You searched for +publisher:"Texas A&M University" +contributor:("Jayasuriya, Suhada").
Showing records 1 – 30 of
31 total matches.
◁ [1] [2] ▶
1.
Lan, Chenyang.
Synthesis of controllers for non-minimum phase and unstable systems using non-sequential MIMO quantitative feedback theory.
Degree: MS, Mechanical Engineering, 2005, Texas A&M University
URL: http://hdl.handle.net/1969.1/2245 
► Considered in this thesis is multi-input multi-output (MIMO) systems with non-minimum phase (NMP) zeros and unstable poles where some of the unstable poles are located…
(more)
▼ Considered in this thesis is multi-input multi-output (MIMO) systems with non-minimum phase (NMP) zeros and unstable poles where some of the unstable poles are located to the right of the NMP zeros. In the single-input single-output (SISO) case such systems pose serious difficulties in controller synthesis for performance and stability. In spite of the added degrees of freedom the MIMO case also poses difficulties as has been shown in the stabilization of the X-29 aircraft. When using the MIMO QFT technique the synthesis starts by considering a set of equivalent SISO plants derived from the plant transfer function matrix that are used to develop a controller. In effect the design problem is reduced to several MISO designs with the diagonal entries of as the equivalent SISO plants. Developed is a transformation scheme that can be used to condition the resulting equivalent SISO plants so that the difficult problem of NMP zeros lying to the left of unstable poles is avoided. Examples illustrate the use of the proposed transformation.
Advisors/Committee Members: Jayasuriya, Suhada (advisor), Parlos, Alexander (committee member), Bhattacharyya, Shankar P. (committee member).
Subjects/Keywords: QFT; Nonminimun phase; Unstable; MIMO Control
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Lan, C. (2005). Synthesis of controllers for non-minimum phase and unstable systems using non-sequential MIMO quantitative feedback theory. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/2245
Chicago Manual of Style (16th Edition):
Lan, Chenyang. “Synthesis of controllers for non-minimum phase and unstable systems using non-sequential MIMO quantitative feedback theory.” 2005. Masters Thesis, Texas A&M University. Accessed April 23, 2021.
http://hdl.handle.net/1969.1/2245.
MLA Handbook (7th Edition):
Lan, Chenyang. “Synthesis of controllers for non-minimum phase and unstable systems using non-sequential MIMO quantitative feedback theory.” 2005. Web. 23 Apr 2021.
Vancouver:
Lan C. Synthesis of controllers for non-minimum phase and unstable systems using non-sequential MIMO quantitative feedback theory. [Internet] [Masters thesis]. Texas A&M University; 2005. [cited 2021 Apr 23].
Available from: http://hdl.handle.net/1969.1/2245.
Council of Science Editors:
Lan C. Synthesis of controllers for non-minimum phase and unstable systems using non-sequential MIMO quantitative feedback theory. [Masters Thesis]. Texas A&M University; 2005. Available from: http://hdl.handle.net/1969.1/2245
2.
Woo, Sang-Bum.
Formation control for cooperative surveillance.
Degree: PhD, Mechanical Engineering, 2009, Texas A&M University
URL: http://hdl.handle.net/1969.1/ETD-TAMU-3203
► Constructing and maintaining a formation is critical in applications of cooperative control of multi-agent systems. In this research we address the formation control problem of…
(more)
▼ Constructing and maintaining a formation is critical in applications of cooperative control of multi-agent systems. In this research we address the formation control
problem of generating a formation for a group of nonholonomic mobile agents. The
formation control scheme proposed in this work is based on a fusion of leader-follower
and virtual reference approaches. This scheme gives a formation constraint representation that is independent of the number of agents in the formation and the resulting
control algorithm is scalable. One of the important desired features in controller design is that the formation errors defined by formation constraints should be stabilized
globally and exponentially by the controller. The proposed controller is based on
feedback linearization, and formation errors are shown to be globally exponentially
stable in the sense of Lyapunov. Since formation errors are stabilized globally, the
proposed controller is applicable to both formation keeping and formation construction problems. As a possible application, the proposed algorithm is implemented in
a cooperative ground moving target surveillance scenario. The proposed algorithm
enables the determination of the minimal number of agents required for surveillance
of a moving target. The number of agents returned by this scheme is not optimal
and hence is a conservative solution. However, this is justified by the computational
savings the scheme offers.
Advisors/Committee Members: Jayasuriya, Suhada (advisor), Bhattacharyya, Shankar P. (committee member), Langari, Reza (committee member), Parlos, Alexander (committee member).
Subjects/Keywords: Formation; cooperative; nonholonomic; multi-robot; surveillance
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Woo, S. (2009). Formation control for cooperative surveillance. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-3203
Chicago Manual of Style (16th Edition):
Woo, Sang-Bum. “Formation control for cooperative surveillance.” 2009. Doctoral Dissertation, Texas A&M University. Accessed April 23, 2021.
http://hdl.handle.net/1969.1/ETD-TAMU-3203.
MLA Handbook (7th Edition):
Woo, Sang-Bum. “Formation control for cooperative surveillance.” 2009. Web. 23 Apr 2021.
Vancouver:
Woo S. Formation control for cooperative surveillance. [Internet] [Doctoral dissertation]. Texas A&M University; 2009. [cited 2021 Apr 23].
Available from: http://hdl.handle.net/1969.1/ETD-TAMU-3203.
Council of Science Editors:
Woo S. Formation control for cooperative surveillance. [Doctoral Dissertation]. Texas A&M University; 2009. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-3203
3.
Dharne, Avinash Gopal.
Issues in autonomous mobile sensor networks.
Degree: PhD, Mechanical Engineering, 2009, Texas A&M University
URL: http://hdl.handle.net/1969.1/ETD-TAMU-1343
► Autonomous mobile sensor networks consist of a number of autonomous mobile robots equipped with various sensors and tasked with a common mission. This thesis considers…
(more)
▼ Autonomous mobile sensor networks consist of a number of autonomous mobile
robots equipped with various sensors and tasked with a common mission. This thesis
considers the topology control of such an ad hoc mobile sensor network. In particular,
I studied the problem of controlling the size, with respect to a distance metric, of the network
for general interactive forcing among agents. Developed is a stability result, allowing
one to design force laws to control the spread of the network. Many of the current results
assume a known and/or fixed topology of the graph representing the communication between
the nodes, i.e. the graph laplacian is assumed constant. They also assume fixed and
known force-laws. Hence, the results are limited to time-invariant dynamics. The research
considers stability analysis of sensor networks, unconstrained by specific forcing functions
or algorithms, and communication topologies. Since the graph topologies are allowed to
change as the agents move about, the system dynamics become discontinuous in nature.
Filippov’s calculus of differential equations with discontinuous right hand sides is used to
formally characterize the multi-agent system with the above attributes. Lyapunov’s Stability
Theory, applied to discontinuous systems, is then used to derive bounds on the norm of
the system states given bounds on its initial states and input.
The above derived stability results lend themselves to the derivation of methods for the
design of algorithms or force-laws for mobile sensor networks. The efficacy of the derived
results is illustrated through several examples where it is shown how they may be used for synthesizing a topology managing strategy. Examples are given of designing force-laws
that limit the network in a desired area.
Advisors/Committee Members: Jayasuriya, Suhada (advisor), Bhattacharyya, Shankar (committee member), Parlos, Alexander (committee member), Welch, Jennifer (committee member).
Subjects/Keywords: Mobile Sensor Networks; Filippov's Calculus; Stability Analysis; Fuzzy Logic; Localization
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Dharne, A. G. (2009). Issues in autonomous mobile sensor networks. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-1343
Chicago Manual of Style (16th Edition):
Dharne, Avinash Gopal. “Issues in autonomous mobile sensor networks.” 2009. Doctoral Dissertation, Texas A&M University. Accessed April 23, 2021.
http://hdl.handle.net/1969.1/ETD-TAMU-1343.
MLA Handbook (7th Edition):
Dharne, Avinash Gopal. “Issues in autonomous mobile sensor networks.” 2009. Web. 23 Apr 2021.
Vancouver:
Dharne AG. Issues in autonomous mobile sensor networks. [Internet] [Doctoral dissertation]. Texas A&M University; 2009. [cited 2021 Apr 23].
Available from: http://hdl.handle.net/1969.1/ETD-TAMU-1343.
Council of Science Editors:
Dharne AG. Issues in autonomous mobile sensor networks. [Doctoral Dissertation]. Texas A&M University; 2009. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-1343
4.
Lal, Mayank.
Motion planning algorithms for a group of mobile agents.
Degree: PhD, Mechanical Engineering, 2008, Texas A&M University
URL: http://hdl.handle.net/1969.1/86038
► Building autonomous mobile agents has been a major research effort for a while with cooperative mobile robotics receiving a lot of attention in recent times.…
(more)
▼ Building autonomous mobile agents has been a major research effort for a while
with cooperative mobile robotics receiving a lot of attention in recent times. Motion
planning is a critical problem in deploying autonomous agents. In this research we
have developed two novel global motion planning schemes for a group of mobile agents
which eliminate some of the disadvantages of the current methods available. The first
is the homotopy method in which the planning is done in polynomial space. In this
method the position in local frame of each mobile agent is mapped to a complex
number and a time varying polynomial contains information regarding the current
positions of all mobile agents, the degree of the polynomial being the number of
mobile agents and the roots of the polynomial representing the position in local
frame of the mobile agents at a given time. This polynomial is constructed by finding
a path parameterized in time from the initial to the goal polynomial (represent the
initial and goal positions in local frame of the mobile agents) so that the discriminant
variety or the set of polynomials with multiple roots is avoided in polynomial space.
This is equivalent to saying that there is no collision between any two agents in going
from initial position to goal position. The second is the homogeneous deformation
method. It is based on continuum theory for motion of deformable bodies. In this
method a swarm of vehicles is considered at rest in an initial configuration with no
restrictions on the initial shape or the locations of the vehicles within that shape. A
motion plan is developed to move this swarm of vehicles from the initial configuration to a new configuration such that there are no collisions between any vehicles at
any time instant. It is achieved via a linear map between the initial and desired
final configuration such that the map is invertible at all times. Both the methods
proposed are computationally attractive. Also they facilitate motion coordination
between groups of mobile agents with limited or no sensing and communication.
Advisors/Committee Members: Jayasuriya, Suhada (advisor), Parlos, Alexander (committee member), Bhattacharyya, Shankar P. (committee member), Datta, Aniruddha (committee member).
Subjects/Keywords: motion planning; mobile agent
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Lal, M. (2008). Motion planning algorithms for a group of mobile agents. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/86038
Chicago Manual of Style (16th Edition):
Lal, Mayank. “Motion planning algorithms for a group of mobile agents.” 2008. Doctoral Dissertation, Texas A&M University. Accessed April 23, 2021.
http://hdl.handle.net/1969.1/86038.
MLA Handbook (7th Edition):
Lal, Mayank. “Motion planning algorithms for a group of mobile agents.” 2008. Web. 23 Apr 2021.
Vancouver:
Lal M. Motion planning algorithms for a group of mobile agents. [Internet] [Doctoral dissertation]. Texas A&M University; 2008. [cited 2021 Apr 23].
Available from: http://hdl.handle.net/1969.1/86038.
Council of Science Editors:
Lal M. Motion planning algorithms for a group of mobile agents. [Doctoral Dissertation]. Texas A&M University; 2008. Available from: http://hdl.handle.net/1969.1/86038
5.
Villota Cerna, Elizabeth Roxana.
Control of systems subject to uncertainty and constraints.
Degree: PhD, Mechanical Engineering, 2009, Texas A&M University
URL: http://hdl.handle.net/1969.1/ETD-TAMU-2550
► All practical control systems are subject to constraints, namely constraints aris¬ing from the actuator’s limited range and rate capacity (input constraints) or from imposed operational…
(more)
▼ All practical control systems are subject to constraints, namely constraints aris¬ing from the actuator’s limited range and rate capacity (input constraints) or from imposed operational limits on plant variables (output constraints). A linear control system typically yields the desirable small signal performance. However, the presence of input constraints often causes undesirable large signal behavior and potential insta¬bility. An anti-windup control consists of a remedial solution that mitigates the effect of input constraints on the closed-loop without affecting the small signal behavior. Conversely, an override control addresses the control problem involving output con¬straints and also follows the idea that large signal control objectives do not alter small signal performance. Importantly, these two remedial control methodologies must in¬corporate model uncertainty into their design to be considered reliable in practice. In this dissertation, shared principles of design for the remedial compensation problem are identified which simplify the picture when analyzing, comparing and synthesiz¬ing for the variety of existing remedial schemes. Two performance objectives, each one related to a different type of remedial compensation, and a general structural representation associated with both remedial compensation problems will be consid¬ered. The effect of remedial control on the closed-loop will be evaluated in terms of two general frameworks which permit the unification and comparison of all known remedial compensation schemes. The difference systems describing the performance objectives will be further employed for comparison of remedial compensation schemes under uncertainty considerations and also for synthesis of compensators. On the ba¬sis of the difference systems and the general structure for remedial compensation, systematic remedial compensation synthesis algorithms for anti-windup and override compensation will be given and compared. Successful application of the proposed robust remedial control synthesis algorithms will be demonstrated via simulation.
Advisors/Committee Members: Jayasuriya, Suhada (advisor), Bhattacharyya, Shankar (committee member), Palazzolo, Alan (committee member), Parlos, Alexander (committee member).
Subjects/Keywords: constraints; uncertainty
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Villota Cerna, E. R. (2009). Control of systems subject to uncertainty and constraints. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-2550
Chicago Manual of Style (16th Edition):
Villota Cerna, Elizabeth Roxana. “Control of systems subject to uncertainty and constraints.” 2009. Doctoral Dissertation, Texas A&M University. Accessed April 23, 2021.
http://hdl.handle.net/1969.1/ETD-TAMU-2550.
MLA Handbook (7th Edition):
Villota Cerna, Elizabeth Roxana. “Control of systems subject to uncertainty and constraints.” 2009. Web. 23 Apr 2021.
Vancouver:
Villota Cerna ER. Control of systems subject to uncertainty and constraints. [Internet] [Doctoral dissertation]. Texas A&M University; 2009. [cited 2021 Apr 23].
Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2550.
Council of Science Editors:
Villota Cerna ER. Control of systems subject to uncertainty and constraints. [Doctoral Dissertation]. Texas A&M University; 2009. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2550
Texas A&M University
6.
Shakir, Huzefa.
Control strategies and motion planning for nanopositioning applications with multi-axis magnetic-levitation instruments.
Degree: PhD, Mechanical Engineering, 2007, Texas A&M University
URL: http://hdl.handle.net/1969.1/5942
► This dissertation is the first attempt to demonstrate the use of magnetic-levitation (maglev) positioners for commercial applications requiring nanopositioning. The key objectives of this research…
(more)
▼ This dissertation is the first attempt to demonstrate the use of magnetic-levitation
(maglev) positioners for commercial applications requiring nanopositioning. The key objectives
of this research were to devise the control strategies and motion planning to overcome the
inherent technical challenges of the maglev systems, and test them on the developed maglev
systems to demonstrate their capabilities as the next-generation nanopositioners. Two maglev
positioners based on novel actuation schemes and capable of generating all the six-axis motions
with a single levitated platen were used in this research. These light-weight single-moving
platens have very simple and compact structures, which give them an edge over most of the
prevailing nanopositioning technologies and allow them to be used as a cluster tool for a variety
of applications. The six-axis motion is generated using minimum number of actuators and
sensors. The two positioners operate with a repeatable position resolution of better than 3 nm at
the control bandwidth of 110 Hz. In particular, the Y-stage has extended travel range of 5 mm ÃÂ 5
mm. They can carry a payload of as much as 0.3 kg and retain the regulated position under
abruptly and continuously varying load conditions. This research comprised analytical design and development, followed by experimental
verification and validation. Preliminary analysis and testing included open-loop stabilization and
rigorous set-point change and load-change testing to demonstrate the precision-positioning and
load-carrying capabilities of the maglev positioners. Decentralized single-input-single-output
(SISO) proportional-integral-derivative (PID) control was designed for this analysis. The effect
of actuator nonlinearities were reduced through actuator characterization and nonlinear feedback
linearization to allow consistent performance over the large travel range. Closed-loop system
identification and order-reduction algorithm were developed in order to analyze and model the
plant behavior accurately, and to reduce the effect of unmodeled plant dynamics and inaccuracies
in the assembly. Coupling among the axes and subsequent undesired motions and crosstalk of
disturbances was reduced by employing multivariable optimal linear-quadratic regulator (LQR).
Finally, application-specific nanoscale path planning strategies and multiscale control were
devised to meet the specified conflicting time-domain performance specifications. All the
developed methodologies and algorithms were implemented, individually as well as collectively,
for experimental verification. Some of these applications included nanoscale lithography,
patterning, fabrication, manipulation, and scanning. With the developed control strategies and
motion planning techniques, the two maglev positioners are ready to be used for the targeted
applications.
Advisors/Committee Members: Kim, Won-jong (advisor), Boyd, Jim (committee member), Jayasuriya, Suhada (committee member), Parlos, Alexander (committee member).
Subjects/Keywords: Nanotechnology; Magnetic-levitation; Precision motion control; Path planning; Multiscale control; System identification
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Shakir, H. (2007). Control strategies and motion planning for nanopositioning applications with multi-axis magnetic-levitation instruments. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/5942
Chicago Manual of Style (16th Edition):
Shakir, Huzefa. “Control strategies and motion planning for nanopositioning applications with multi-axis magnetic-levitation instruments.” 2007. Doctoral Dissertation, Texas A&M University. Accessed April 23, 2021.
http://hdl.handle.net/1969.1/5942.
MLA Handbook (7th Edition):
Shakir, Huzefa. “Control strategies and motion planning for nanopositioning applications with multi-axis magnetic-levitation instruments.” 2007. Web. 23 Apr 2021.
Vancouver:
Shakir H. Control strategies and motion planning for nanopositioning applications with multi-axis magnetic-levitation instruments. [Internet] [Doctoral dissertation]. Texas A&M University; 2007. [cited 2021 Apr 23].
Available from: http://hdl.handle.net/1969.1/5942.
Council of Science Editors:
Shakir H. Control strategies and motion planning for nanopositioning applications with multi-axis magnetic-levitation instruments. [Doctoral Dissertation]. Texas A&M University; 2007. Available from: http://hdl.handle.net/1969.1/5942
Texas A&M University
7.
Gu, Jie.
Development of a 6-degree-of-freedom magnetically levitated instrument with nanometer precision.
Degree: MS, Mechanical Engineering, 2004, Texas A&M University
URL: http://hdl.handle.net/1969.1/118
► This thesis presents the design and fabrication of a novel magnetically levitated (maglev) device with six-degree-of-freedom motion capability at nanometer precision. The applications of this…
(more)
▼ This thesis presents the design and fabrication of a novel magnetically levitated (maglev) device with six-degree-of-freedom motion capability at nanometer precision. The applications of this device are manufacture of nanoscale structures, assembly of microparts, vibration isolation of delicate instrumentation, and telerobotics. In this thesis, a single-moving stage is levitated by six maglev actuators. The total mass of the moving stage is 0.2126 kg. Three laser interferometers and three capacitance sensors are used to gather the position information. User interface and real-time control routines are implemented digitally on a VME PC and a digital-signal-processor (DSP) board. The underlying mechanical design and fabrication, electrical system setup, control system design, noise analysis, and test results are presented in this thesis. Test results show a quick step response in all six axes and a resolution of 2.5 nm rms in horizontal motion and 25 nm rms in vertical motion.
Advisors/Committee Members: Kim, Won-jong (advisor), Chan, Andrew K. (committee member), Jayasuriya, Suhada (committee member).
Subjects/Keywords: maglev; mechatronics; nanomanipulation; 6-DOF; nanopositioning
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Gu, J. (2004). Development of a 6-degree-of-freedom magnetically levitated instrument with nanometer precision. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/118
Chicago Manual of Style (16th Edition):
Gu, Jie. “Development of a 6-degree-of-freedom magnetically levitated instrument with nanometer precision.” 2004. Masters Thesis, Texas A&M University. Accessed April 23, 2021.
http://hdl.handle.net/1969.1/118.
MLA Handbook (7th Edition):
Gu, Jie. “Development of a 6-degree-of-freedom magnetically levitated instrument with nanometer precision.” 2004. Web. 23 Apr 2021.
Vancouver:
Gu J. Development of a 6-degree-of-freedom magnetically levitated instrument with nanometer precision. [Internet] [Masters thesis]. Texas A&M University; 2004. [cited 2021 Apr 23].
Available from: http://hdl.handle.net/1969.1/118.
Council of Science Editors:
Gu J. Development of a 6-degree-of-freedom magnetically levitated instrument with nanometer precision. [Masters Thesis]. Texas A&M University; 2004. Available from: http://hdl.handle.net/1969.1/118
Texas A&M University
8.
Srivastava, Abhinav.
Distributed real-time control via the internet.
Degree: MS, Mechanical Engineering, 2004, Texas A&M University
URL: http://hdl.handle.net/1969.1/165
► The objective of this research is to demonstrate experimentally the feasibility of using the Internet for a Distributed Control System (DCS). An algorithm has been…
(more)
▼ The objective of this research is to demonstrate experimentally the feasibility of using the Internet for a Distributed Control System (DCS). An algorithm has been designed and implemented to ensure stability of the system in the presence of upper bounded time-varying delays. A single actuator magnetic ball levitation system has been used as a test bed to validate the proposed algorithm. Experiments were performed to obtain the round-trip time delay between the host PC and the client PC under varying network loads and at different times. A digital real-time lead-lag controller was implemented for the magnetic levitation system. Upper bounds for the artificial and experimental round-trip time delay that can be accommodated in the control loop for the maglev system were estimated. The artificial time delay was based on various probabilistic distributions and was generated through MATLAB. To accommodate sporadic surges in time delays that are more than these upper bounds, a timeout algorithm with sensor data prediction was developed. Experiments were performed to validate the satisfactory performance of this algorithm in the presence of the bonded sporadic excessive time delays.
Advisors/Committee Members: Kim, Won-jong (advisor), Volz, Richard A. (committee member), Jayasuriya, Suhada (committee member).
Subjects/Keywords: Real-Time; the Internet; Control System; Time Delay; Internet Protocols
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Srivastava, A. (2004). Distributed real-time control via the internet. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/165
Chicago Manual of Style (16th Edition):
Srivastava, Abhinav. “Distributed real-time control via the internet.” 2004. Masters Thesis, Texas A&M University. Accessed April 23, 2021.
http://hdl.handle.net/1969.1/165.
MLA Handbook (7th Edition):
Srivastava, Abhinav. “Distributed real-time control via the internet.” 2004. Web. 23 Apr 2021.
Vancouver:
Srivastava A. Distributed real-time control via the internet. [Internet] [Masters thesis]. Texas A&M University; 2004. [cited 2021 Apr 23].
Available from: http://hdl.handle.net/1969.1/165.
Council of Science Editors:
Srivastava A. Distributed real-time control via the internet. [Masters Thesis]. Texas A&M University; 2004. Available from: http://hdl.handle.net/1969.1/165
Texas A&M University
9.
Arora, Sumit.
Online regulations of low order systems under bounded control.
Degree: MS, Mechanical Engineering, 2004, Texas A&M University
URL: http://hdl.handle.net/1969.1/376
► Time-optimal solutions provide us with the fastest means to regulate a system in presence of input constraints. This advantage of time-optimal control solutions is offset…
(more)
▼ Time-optimal solutions provide us with the fastest means to regulate a system in presence of input constraints. This advantage of time-optimal control solutions is offset by the fact that their real-time implementation involves computationally intensive iterative techniques. Moreover, time-optimal controls depend on the initial state and have to be recalculated for even the slightest perturbation. Clearly time-optimal controls are not good candidates for online regulation. Consequently, the search for alternatives to time-optimal solutions is a very active area of research. The work described here is inspired by the simplicity of optimal-aim concept. The "optimal-aim strategies" provide online regulation in presence of bounded inputs with minimal computational effort. These are based purely on state-space geometry of the plant and are inherently adaptive in nature. Optimal-aim techniques involve aiming of trajectory derivative (or the state velocity vector) so as to approach the equilibrium state in the best possible manner. This thesis documents the efforts to develop an online regulation algorithm for systems with input constraints. Through a number of hypotheses focussed on trying to reproduce the exact time-optimal solution, the diffculty associated with this task is demonstrated. A modification of optimal-aim concept is employed to develop a novel regulation algorithm. In this algorithm, aim directions are chosen in a special manner to generate the time-optimal control approximately. The control scheme thus developed is shown to be globally stabilizing for systems having eigenvalues in the CLHP (closed left half-plane). It is expected that this method or its modifications can be extended to higher dimensional systems as a part of future research. An alternative control algorithm involving a simple state-space aiming concept is also developed and discussed.
Advisors/Committee Members: Jayasuriya, Suhada (advisor), Langari, Reza (committee member), Walton, Jay R. (committee member).
Subjects/Keywords: constrained inputs; bounded control; regulation; time-optimal control; optimal-aim; aiming techniques
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Arora, S. (2004). Online regulations of low order systems under bounded control. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/376
Chicago Manual of Style (16th Edition):
Arora, Sumit. “Online regulations of low order systems under bounded control.” 2004. Masters Thesis, Texas A&M University. Accessed April 23, 2021.
http://hdl.handle.net/1969.1/376.
MLA Handbook (7th Edition):
Arora, Sumit. “Online regulations of low order systems under bounded control.” 2004. Web. 23 Apr 2021.
Vancouver:
Arora S. Online regulations of low order systems under bounded control. [Internet] [Masters thesis]. Texas A&M University; 2004. [cited 2021 Apr 23].
Available from: http://hdl.handle.net/1969.1/376.
Council of Science Editors:
Arora S. Online regulations of low order systems under bounded control. [Masters Thesis]. Texas A&M University; 2004. Available from: http://hdl.handle.net/1969.1/376
Texas A&M University
10.
Shah, Chirag Laxmikant.
On the modeling of time-varying delays.
Degree: MS, Mechanical Engineering, 2004, Texas A&M University
URL: http://hdl.handle.net/1969.1/379
► This thesis is an effort to develop generalized dynamic models for systems with time-varying time delays. Unlike the simple time-delay model characterized by a transportation…
(more)
▼ This thesis is an effort to develop generalized dynamic models for systems with time-varying time delays. Unlike the simple time-delay model characterized by a transportation lag in the case of a fixed time delay, time-varying delays exhibit quite different characteristics, making the development of easy to use models a difficult endeavor. First an algorithm is developed to predict the actual input-output behavior when the input signal is directly fed into a device that characterizes the time-varying delay. Input-output behaviour generated with this algorithm serves as the truth model for subsequent approximate model development. Simulation results for different classes of delay and different inputs were obtained using the truth model. The input functions were limited to steps, ramps and sinusoids. This limited class of inputs and delays defines the scope of this thesis and the results are to be interpreted as such. The methodology adopted to identify the basic underpinnings of models was system identification where input-output data came from the truth model. Models for the aforementioned classes of inputs and delays were then derived using elementary system identification tools. These models were then carefully analyzed to extract trends by changing the delay parameter. A satisfactory trend was observed in the case of linearly varying time delay. A generalized model for the linearly varying time delay with step and polynomial inputs was developed. An attempt was also made at developing a generalized model for sinusoidally time-varying time delays. This study proposes a model for linearly time-varying time delay, whose structure is not surprisingly also dependent on the class of inputs. It is shown that the derived model reduces to the well known model in the case of a fixed delay.
Advisors/Committee Members: Jayasuriya, Suhada (advisor), Kim, Won-jong (committee member), Bhattacharyya, Shankar (committee member).
Subjects/Keywords: Time-varying delays; Modeling delays; Variable tansport block
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Shah, C. L. (2004). On the modeling of time-varying delays. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/379
Chicago Manual of Style (16th Edition):
Shah, Chirag Laxmikant. “On the modeling of time-varying delays.” 2004. Masters Thesis, Texas A&M University. Accessed April 23, 2021.
http://hdl.handle.net/1969.1/379.
MLA Handbook (7th Edition):
Shah, Chirag Laxmikant. “On the modeling of time-varying delays.” 2004. Web. 23 Apr 2021.
Vancouver:
Shah CL. On the modeling of time-varying delays. [Internet] [Masters thesis]. Texas A&M University; 2004. [cited 2021 Apr 23].
Available from: http://hdl.handle.net/1969.1/379.
Council of Science Editors:
Shah CL. On the modeling of time-varying delays. [Masters Thesis]. Texas A&M University; 2004. Available from: http://hdl.handle.net/1969.1/379
Texas A&M University
11.
Ambike, Ajit Dilip.
Closed-loop real-time control on distributed networks.
Degree: MS, Mechanical Engineering, 2004, Texas A&M University
URL: http://hdl.handle.net/1969.1/1079
► This thesis is an effort to develop closed-loop control strategies on computer networks and study their stability in the presence of network delays and packet…
(more)
▼ This thesis is an effort to develop closed-loop control strategies on computer networks and study their stability in the presence of network delays and packet losses. An algorithm using predictors was designed to ensure the system stability in presence of network delays and packet losses. A single actuator magnetic ball levitation system was used as a test bed to validate the proposed algorithm. A brief study of real-time requirements of the networked control system is presented and a client-server architecture is developed using real-time operating environment to implement the proposed algorithm. Real-time performance of the communication on Ethernet based on user datagram protocol (UDP) was explored and UDP is presented as a suitable protocol for networked control systems. Predictors were designed based on parametric estimation models. Autoregressive (AR) and autoregressive moving average (ARMA) models of various orders were designed using MATLAB and an eighth order AR model was adopted based on the best-fit criterion. The system output was predicted several steps ahead using these predictors and control output was calculated using the predictions. This control output output was used in the events of excessive network delays to maintain system stability. Experiments employing simulations of consecutive packet losses and network delays were performed to validate the satisfactory performance of the predictor based algorithm. The current system compensates for up to 20 percent data losses in the network without loosing stability.
Advisors/Committee Members: Kim, Won-jong (advisor), Volz, Richard (committee member), Jayasuriya, Suhada (committee member).
Subjects/Keywords: Networked Control System; Distributed Control System
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Ambike, A. D. (2004). Closed-loop real-time control on distributed networks. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/1079
Chicago Manual of Style (16th Edition):
Ambike, Ajit Dilip. “Closed-loop real-time control on distributed networks.” 2004. Masters Thesis, Texas A&M University. Accessed April 23, 2021.
http://hdl.handle.net/1969.1/1079.
MLA Handbook (7th Edition):
Ambike, Ajit Dilip. “Closed-loop real-time control on distributed networks.” 2004. Web. 23 Apr 2021.
Vancouver:
Ambike AD. Closed-loop real-time control on distributed networks. [Internet] [Masters thesis]. Texas A&M University; 2004. [cited 2021 Apr 23].
Available from: http://hdl.handle.net/1969.1/1079.
Council of Science Editors:
Ambike AD. Closed-loop real-time control on distributed networks. [Masters Thesis]. Texas A&M University; 2004. Available from: http://hdl.handle.net/1969.1/1079
Texas A&M University
12.
Konstantinou, Apostolos.
Flow control techniques for real-time media applications in best-effort networks using fluid models.
Degree: MS, Mechanical Engineering, 2004, Texas A&M University
URL: http://hdl.handle.net/1969.1/1085
► Quality of Service (QoS) in real-time media applications is an area of current interest because of the increasing demand for audio/video, and generally multimedia applications,…
(more)
▼ Quality of Service (QoS) in real-time media applications is an area of current interest because of the increasing demand for audio/video, and generally multimedia applications, over best effort networks, such as the Internet. Media applications are transported using the User Datagram Protocol (UDP) and tend to use a disproportionate amount of network bandwidth as they do not perform congestion or flow control. Methods for application QoS control are desirable to enable users to perceive a consistent media quality. This can be accomplished by either modifying current protocols at the transport layer or by implementing new control algorithms at the application layer irrespective of the protocol used at the transport layer.
The objective of this research is to improve the QoS delivered to end-users in real-time applications transported over best-effort packet-switched networks. This is accomplished using UDP at the transport layer, along with adaptive predictive and reactive control at the application layer. An end-to-end fluid model is used, including the source buffer, the network and the destination buffer. Traditional control techniques, along with more advanced adaptive predictive control methods, are considered in order to provide the desirable QoS and make a best-effort network an attractive channel for interactive multimedia applications. The effectiveness of the control methods, is examined using a Simulink-based fluid-level simulator in combination with trace files extracted from the well-known network simulator ns-2. The results show that improvement in real-time applications transported over best-effort networks using unreliable transport protocols, such as UDP, is feasible. The improvement in QoS is reflected in the reduction of flow loss at the expense of flow dead-time increase or playback disruptions or both.
Advisors/Committee Members: Parlos, Alexander (advisor), Welch, Jennifer L. (committee member), Jayasuriya, Suhada (committee member).
Subjects/Keywords: flow control; fluid models; network
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Konstantinou, A. (2004). Flow control techniques for real-time media applications in best-effort networks using fluid models. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/1085
Chicago Manual of Style (16th Edition):
Konstantinou, Apostolos. “Flow control techniques for real-time media applications in best-effort networks using fluid models.” 2004. Masters Thesis, Texas A&M University. Accessed April 23, 2021.
http://hdl.handle.net/1969.1/1085.
MLA Handbook (7th Edition):
Konstantinou, Apostolos. “Flow control techniques for real-time media applications in best-effort networks using fluid models.” 2004. Web. 23 Apr 2021.
Vancouver:
Konstantinou A. Flow control techniques for real-time media applications in best-effort networks using fluid models. [Internet] [Masters thesis]. Texas A&M University; 2004. [cited 2021 Apr 23].
Available from: http://hdl.handle.net/1969.1/1085.
Council of Science Editors:
Konstantinou A. Flow control techniques for real-time media applications in best-effort networks using fluid models. [Masters Thesis]. Texas A&M University; 2004. Available from: http://hdl.handle.net/1969.1/1085
Texas A&M University
13.
Khariwal, Vivek.
Adaptive control of real-time media applications in best-effort networks.
Degree: MS, Mechanical Engineering, 2004, Texas A&M University
URL: http://hdl.handle.net/1969.1/1236
► Quality of Service (QoS) in real-time media applications can be defined as the ability to guarantee the delivery of packets from source to destination over…
(more)
▼ Quality of Service (QoS) in real-time media applications can be defined as the
ability to guarantee the delivery of packets from source to destination over best-effort
networks within some constraints. These constraints defined as the QoS metrics are
end-to-end packet delay, delay jitter, throughtput, and packet losses. Transporting
real-time media applications over best-effort networks, e.g. the Internet, is an area
of current research. Both the Transmission Control Protocol (TCP) and the User
Datagram Protocol (UDP) have failed to provide the desired QoS. This research aims
at developing application-level end-to-end QoS controls to improve the user-perceived
quality of real-time media applications over best-effort networks, such as, the public
Internet.
In this research an end-to-end packet based approach is developed. The end-to-
end packet based approach consists of source buffer, network simulator ns-2, destina-
tion buffer, and controller. Unconstrained model predictive control (MPC) methods
are implemented by the controller at the application layer. The end-to-end packet
based approach uses end-to-end network measurements and predictions as feedback
signals. Effectiveness of the developed control methods are examined using Matlab
and ns-2. The results demonstrate that sender-based control schemes utilizing UDP
at transport layer are effective in providing QoS for real-time media applications
transported over best-effort networks. Significant improvements in providing QoS are
visible by the reduction of packet losses and the elimination of disruptions during the
playback of real-time media. This is accompanied by either a decrease or increase in
the playback start-time.
Advisors/Committee Members: Parlos, Alexander (advisor), Welch, Jennifer (committee member), Jayasuriya, Suhada (committee member).
Subjects/Keywords: QoS; Real-time media; End-to-end packet based approach; Unconstrained Model Predictive Control
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Khariwal, V. (2004). Adaptive control of real-time media applications in best-effort networks. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/1236
Chicago Manual of Style (16th Edition):
Khariwal, Vivek. “Adaptive control of real-time media applications in best-effort networks.” 2004. Masters Thesis, Texas A&M University. Accessed April 23, 2021.
http://hdl.handle.net/1969.1/1236.
MLA Handbook (7th Edition):
Khariwal, Vivek. “Adaptive control of real-time media applications in best-effort networks.” 2004. Web. 23 Apr 2021.
Vancouver:
Khariwal V. Adaptive control of real-time media applications in best-effort networks. [Internet] [Masters thesis]. Texas A&M University; 2004. [cited 2021 Apr 23].
Available from: http://hdl.handle.net/1969.1/1236.
Council of Science Editors:
Khariwal V. Adaptive control of real-time media applications in best-effort networks. [Masters Thesis]. Texas A&M University; 2004. Available from: http://hdl.handle.net/1969.1/1236
Texas A&M University
14.
Bhoite, Sameer Prabhakarrao.
Impact of wireless losses on the predictability of end-to-end flow characteristics in Mobile IP Networks.
Degree: MS, Mechanical Engineering, 2005, Texas A&M University
URL: http://hdl.handle.net/1969.1/1510
► Technological advancements have led to an increase in the number of wireless and mobile devices such as PDAs, laptops and smart phones. This has resulted…
(more)
▼ Technological advancements have led to an increase in the number of wireless and
mobile devices such as PDAs, laptops and smart phones. This has resulted in an ever-
increasing demand for wireless access to the Internet. Hence, wireless mobile traffic
is expected to form a significant fraction of Internet traffic in the near future, over
the so-called Mobile Internet Protocol (MIP) networks. For real-time applications,
such as voice, video and process monitoring and control, deployed over standard IP
networks, network resources must be properly allocated so that the mobile end-user
is guaranteed a certain Quality of Service (QoS). As with the wired and fixed IP
networks, MIP networks do not offer any QoS guarantees. Such networks have been
designed for non-real-time applications. In attempts to deploy real-time applications
in such networks without requiring major network infrastructure modifications, the
end-points must provide some level of QoS guarantees. Such QoS guarantees or QoS
control, requires ability of predictive capabilities of the end-to-end flow characteristics.
In this research network flow accumulation is used as a measure of end-to-end
network congestion. Careful analysis and study of the flow accumulation signal shows
that it has long-term dependencies and it is very noisy, thus making it very difficult
to predict. Hence, this work predicts the moving average of the flow accumulation
signal. Both single-step and multi-step predictors are developed using linear system
identification techniques. A multi-step prediction error of up to 17% is achieved for
prediction horizon of up to 0.5sec.
The main thrust of this research is on the impact of wireless losses on the ability to
predict end-to-end flow accumulation. As opposed to wired, congestion related packet
losses, the losses occurring in a wireless channel are to a large extent random, making
the prediction of flow accumulation more challenging. Flow accumulation prediction
studies in this research demonstrate that, if an accurate predictor is employed, the
increase in prediction error is up to 170% when wireless loss reaches as high as 15% ,
as compared to the case of no wireless loss. As the predictor accuracy in the case of
no wireless loss deteriorates, the impact of wireless losses on the flow accumulation
prediction error decreases.
Advisors/Committee Members: Parlos, Alexander G. (advisor), Pappu, Madhav (committee member), Jayasuriya, Suhada (committee member).
Subjects/Keywords: QoS in MIP Networks; Mobile IP Networks; QoS; Impact of wireless losses; End-to-End dynamics of Mobile IP Networks
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Bhoite, S. P. (2005). Impact of wireless losses on the predictability of end-to-end flow characteristics in Mobile IP Networks. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/1510
Chicago Manual of Style (16th Edition):
Bhoite, Sameer Prabhakarrao. “Impact of wireless losses on the predictability of end-to-end flow characteristics in Mobile IP Networks.” 2005. Masters Thesis, Texas A&M University. Accessed April 23, 2021.
http://hdl.handle.net/1969.1/1510.
MLA Handbook (7th Edition):
Bhoite, Sameer Prabhakarrao. “Impact of wireless losses on the predictability of end-to-end flow characteristics in Mobile IP Networks.” 2005. Web. 23 Apr 2021.
Vancouver:
Bhoite SP. Impact of wireless losses on the predictability of end-to-end flow characteristics in Mobile IP Networks. [Internet] [Masters thesis]. Texas A&M University; 2005. [cited 2021 Apr 23].
Available from: http://hdl.handle.net/1969.1/1510.
Council of Science Editors:
Bhoite SP. Impact of wireless losses on the predictability of end-to-end flow characteristics in Mobile IP Networks. [Masters Thesis]. Texas A&M University; 2005. Available from: http://hdl.handle.net/1969.1/1510
Texas A&M University
15.
Lal, Mayank.
Cascade design of single input single output systems using H∞ and quantitative feedback theory methodologies.
Degree: MS, Mechanical Engineering, 2005, Texas A&M University
URL: http://hdl.handle.net/1969.1/1520
► This thesis considers the design of cascaded SISO control systems using the H∞ and QFT methodologies. In the first part of the thesis the actual…
(more)
▼ This thesis considers the design of cascaded SISO control systems using the H∞
and QFT methodologies. In the first part of the thesis the actual advantages offered by
Single Input Single Output (SISO) cascade loop structures are studied. In Quantitative
Feedback Theory(QFT) it is emphasized that the use of cascaded loops is primarily for
the reduction of bandwidth of the controllers. This in turn helps in considerable
reduction of the adverse effects of high frequency noise. The question that arises then is
whether or not there are any substantial benefits to be gained by cascade loop design in
the low frequencies. It is shown using QFT methodology that there arent any advantages
gained in the low frequencies with the use of cascaded design. In effect it is concluded
that if the design is properly executed a single loop controller closed from the output to
the input will be sufficient to meet the typical performance specifications. This is shown
using an example where the mold level of a continuous casting process is to be
controlled. The plant being used has considerable uncertainty so that features of robust
control can be highlighted.
In the second part the Robust Outer Loop bounds were generated analytically and
examined for certain properties. It was compared to the bounds generated by already
existing algorithms.
In the third part the inner outer QFT design was modified with the inner loop
being designed using H∞ with the concept of sensitivity shaping. This design was very
similar to the pure QFT design with the added advantage of having some automation.
In the fourth part the H∞ methodology was used to design a two loop control
structure. The idea was to compare this design to the QFT design. It was seen that H∞
generated redundant controllers and pre filters.
Advisors/Committee Members: Jayasuriya, Suhada (advisor), Parlos, Alexander (committee member), Bhattacharyya, Shankar P. (committee member).
Subjects/Keywords: Cascade; Quantitative Feedback Theory; H∞
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Lal, M. (2005). Cascade design of single input single output systems using H∞ and quantitative feedback theory methodologies. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/1520
Chicago Manual of Style (16th Edition):
Lal, Mayank. “Cascade design of single input single output systems using H∞ and quantitative feedback theory methodologies.” 2005. Masters Thesis, Texas A&M University. Accessed April 23, 2021.
http://hdl.handle.net/1969.1/1520.
MLA Handbook (7th Edition):
Lal, Mayank. “Cascade design of single input single output systems using H∞ and quantitative feedback theory methodologies.” 2005. Web. 23 Apr 2021.
Vancouver:
Lal M. Cascade design of single input single output systems using H∞ and quantitative feedback theory methodologies. [Internet] [Masters thesis]. Texas A&M University; 2005. [cited 2021 Apr 23].
Available from: http://hdl.handle.net/1969.1/1520.
Council of Science Editors:
Lal M. Cascade design of single input single output systems using H∞ and quantitative feedback theory methodologies. [Masters Thesis]. Texas A&M University; 2005. Available from: http://hdl.handle.net/1969.1/1520
Texas A&M University
16.
Maithripala, Diyogu Hennadige Asanka.
Radar deception through phantom track generation.
Degree: MS, Mechanical Engineering, 2006, Texas A&M University
URL: http://hdl.handle.net/1969.1/3169
► This thesis presents a control algorithm to be used by a team of ECAVs (Electronic Combat Air Vehicle) to deceive a network of radars through…
(more)
▼ This thesis presents a control algorithm to be used by a team of ECAVs (Electronic Combat
Air Vehicle) to deceive a network of radars through the generation of a phantom track.
Each ECAV has the electronic capability of intercepting and introducing an appropriate
time delay to a transmitted pulse of a radar before transmitting it back to the radar, thereby
deceiving the radar into seeing a phantom target at a range beyond that of the ECAV. A radar
network correlates targets and target tracks to detect range delay based deception. A team of
cooperating ECAVs, however, precisely plans their trajectories in a way all the radars in the
radar network are deceived into seeing the same phantom. Since each radar in the network
confirms the target track of the other, the phantom track is considered valid. An important
feature of the algorithm achieving this is that it translates kinematic constraints on the
ECAV dynamic system into constraints on the phantom point. The phantom track between
two specified way points then evolves without violating any of the system constraints. The
evolving phantom track in turn generates the actual controls on the ECAVs so that ECAVs
have flyable trajectories. The algorithms give feasible but suboptimal solutions. The main
objectives are algorithm development for phantom track generation through a team of cooperating
ECAVs, development of the algorithms to be finite dimensional searches and
determining necessary conditions for feasible solutions in the immediate horizon of the
searches of the algorithm. Feasibility of the algorithm in deceiving a radar network through
phantom track generation is demonstrated through simulation results.
Advisors/Committee Members: Jayasuriya, Suhada (advisor), Datta, Aniruddha (committee member), Parlos, Alexander (committee member).
Subjects/Keywords: Autonomous systems; Cooperative control; Optimization algorithms
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Maithripala, D. H. A. (2006). Radar deception through phantom track generation. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/3169
Chicago Manual of Style (16th Edition):
Maithripala, Diyogu Hennadige Asanka. “Radar deception through phantom track generation.” 2006. Masters Thesis, Texas A&M University. Accessed April 23, 2021.
http://hdl.handle.net/1969.1/3169.
MLA Handbook (7th Edition):
Maithripala, Diyogu Hennadige Asanka. “Radar deception through phantom track generation.” 2006. Web. 23 Apr 2021.
Vancouver:
Maithripala DHA. Radar deception through phantom track generation. [Internet] [Masters thesis]. Texas A&M University; 2006. [cited 2021 Apr 23].
Available from: http://hdl.handle.net/1969.1/3169.
Council of Science Editors:
Maithripala DHA. Radar deception through phantom track generation. [Masters Thesis]. Texas A&M University; 2006. Available from: http://hdl.handle.net/1969.1/3169
Texas A&M University
17.
Gupta, Deepanker.
Multi-step-ahead prediction of MPEG-coded video source traffic using empirical modeling techniques.
Degree: MS, Mechanical Engineering, 2006, Texas A&M University
URL: http://hdl.handle.net/1969.1/3201
► In the near future, multimedia will form the majority of Internet traffic and the most popular standard used to transport and view video is MPEG.…
(more)
▼ In the near future, multimedia will form the majority of Internet traffic and
the most popular standard used to transport and view video is MPEG. The MPEG
media content data is in the form of a time-series representing frame/VOP sizes.
This time-series is extremely noisy and analysis shows that it has very long-range
time dependency making it even harder to predict than any typical time-series. This
work is an effort to develop multi-step-ahead predictors for the moving averages of
frame/VOP sizes in MPEG-coded video streams.
In this work, both linear and non-linear system identification tools are used to
solve the prediction problem, and their performance is compared. Linear modeling is
done using Auto-Regressive Exogenous (ARX) models and for non linear modeling,
Artificial Neural Networks (ANN) are employed. The different ANN architectures
used in this work are Feed-forward Multi-Layer Perceptron (FMLP) and Recurrent
Multi-Layer Perceptron (RMLP).
Recent researches by Adas (October 1998), Yoo (March 2002) and Bhattacharya
et al. (August 2003) have shown that the multi-step-ahead prediction of individual
frames is very inaccurate. Therefore, for this work, we predict the moving average
of the frame/VOP sizes instead of individual frame/VOPs. Several multi-step-ahead
predictors are developed using the aforementioned linear and non-linear tools for
two/four/six/ten-step-ahead predictions of the moving average of the frame/VOP
size time-series of MPEG coded video source traffic.
The capability to predict future frame/VOP sizes and hence the bit rates will
enable more effective bandwidth allocation mechanism, assisting in the development
of advanced source control schemes needed to control multimedia traffic over wide
area networks, such as the Internet.
Advisors/Committee Members: Parlos, Alexander G (advisor), Datta, Aniruddha (committee member), Jayasuriya, Suhada (committee member).
Subjects/Keywords: MPEG; prediction; empirical modeling techniques; neural networks
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Gupta, D. (2006). Multi-step-ahead prediction of MPEG-coded video source traffic using empirical modeling techniques. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/3201
Chicago Manual of Style (16th Edition):
Gupta, Deepanker. “Multi-step-ahead prediction of MPEG-coded video source traffic using empirical modeling techniques.” 2006. Masters Thesis, Texas A&M University. Accessed April 23, 2021.
http://hdl.handle.net/1969.1/3201.
MLA Handbook (7th Edition):
Gupta, Deepanker. “Multi-step-ahead prediction of MPEG-coded video source traffic using empirical modeling techniques.” 2006. Web. 23 Apr 2021.
Vancouver:
Gupta D. Multi-step-ahead prediction of MPEG-coded video source traffic using empirical modeling techniques. [Internet] [Masters thesis]. Texas A&M University; 2006. [cited 2021 Apr 23].
Available from: http://hdl.handle.net/1969.1/3201.
Council of Science Editors:
Gupta D. Multi-step-ahead prediction of MPEG-coded video source traffic using empirical modeling techniques. [Masters Thesis]. Texas A&M University; 2006. Available from: http://hdl.handle.net/1969.1/3201
Texas A&M University
18.
Kim, Kihwan.
Feedback control of flow separation using synthetic jets.
Degree: PhD, Mechanical Engineering, 2006, Texas A&M University
URL: http://hdl.handle.net/1969.1/3252
► The primary goal of this research is to assess the effect of synthetic jets on flow separation and provide a feedback control strategy for flow…
(more)
▼ The primary goal of this research is to assess the effect of synthetic jets on flow separation
and provide a feedback control strategy for flow separation using synthetic jets.
The feedback control synthesis is conducted based upon CFD simulation for a rounded
backward-facing step. The results of the synthetic jet experiments on an airfoil showed
that synthetic jets have the potential for controlling the degree of flow separation beyond
delaying the onset of flow separation. In the simulation, while the jet is ejected slightly
upstream from the separation point, the feedback pressure signal is acquired at a downstream
wall point where the vortex is fully developed. Due to the uniqueness of synthetic
jets, i.e. "zero-net-mass flux", the profile of synthetic jet velocity cannot be arbitrarily generated.
The possible control variables are the magnitude or frequency of the oscillating jet
velocity. Consequently, the fluidic system in simulation consists of the actuator model and
the NARMAX (Nonlinear Auto Regressive Moving Average with eXogenous inputs) flow
model. This system shows a strong nonlinear pressure response to the input jet frequency.
Low-pass filtering of the pressure response, introduced for pressure recovery, facilitates
a quasi-linear approximation of the system in the frequency domain using the describing
function method. The low-pass filter effectively separates the pressure response into two
frequency bands. The lower frequency band below the filter pass frequency includes the
quasi-linear response targeted by the feedback control and the higher band above the filter
stop frequency contains the attenuated higher harmonics, which are treated as nonlinear disturbances. This quasi-linear approximation is utilized to design a PI controller for the
fluidic system including the synthetic jet. To ensure one-to-one correspondence of the jet
frequency and the filtered pressure response, the upper bound of the jet frequency is set at
the frequency of the maximum pressure. The response of the resulting closed loop feedback
control system, comprised of a PI controller, low-pass filter, SJA model and NARMAX
model, is shown to track the desired pressure command with an improvement in the
transient response over the open-loop system.
Advisors/Committee Members: Jayasuriya, Suhada (advisor), Beskok, Ali (committee member), Parlos, Alexander (committee member), Rediniotis, Othon (committee member).
Subjects/Keywords: Flow Control; Synthetic Jets
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Kim, K. (2006). Feedback control of flow separation using synthetic jets. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/3252
Chicago Manual of Style (16th Edition):
Kim, Kihwan. “Feedback control of flow separation using synthetic jets.” 2006. Doctoral Dissertation, Texas A&M University. Accessed April 23, 2021.
http://hdl.handle.net/1969.1/3252.
MLA Handbook (7th Edition):
Kim, Kihwan. “Feedback control of flow separation using synthetic jets.” 2006. Web. 23 Apr 2021.
Vancouver:
Kim K. Feedback control of flow separation using synthetic jets. [Internet] [Doctoral dissertation]. Texas A&M University; 2006. [cited 2021 Apr 23].
Available from: http://hdl.handle.net/1969.1/3252.
Council of Science Editors:
Kim K. Feedback control of flow separation using synthetic jets. [Doctoral Dissertation]. Texas A&M University; 2006. Available from: http://hdl.handle.net/1969.1/3252
Texas A&M University
19.
Pandey, Amit Nath.
Fault detection of multivariable system using its directional properties.
Degree: MS, Mechanical Engineering, 2006, Texas A&M University
URL: http://hdl.handle.net/1969.1/3354
► A novel algorithm for making the combination of outputs in the output zero direction of the plant always equal to zero was formulated. Using this…
(more)
▼ A novel algorithm for making the combination of outputs in the output zero direction of
the plant always equal to zero was formulated. Using this algorithm and the result of
MacFarlane and Karcanias, a fault detection scheme was proposed which utilizes the
directional property of the multivariable linear system. The fault detection scheme is
applicable to linear multivariable systems. Results were obtained for both continuous and
discrete linear multivariable systems. A quadruple tank system was used to illustrate the
results. The results were further verified by the steady state analysis of the plant.
Advisors/Committee Members: Jayasuriya, Suhada (advisor), Parlos, Alexander (committee member), Bhattacharyya, Shankar (committee member).
Subjects/Keywords: fault detection; transmission zero; input zero direction; output zero direction
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Pandey, A. N. (2006). Fault detection of multivariable system using its directional properties. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/3354
Chicago Manual of Style (16th Edition):
Pandey, Amit Nath. “Fault detection of multivariable system using its directional properties.” 2006. Masters Thesis, Texas A&M University. Accessed April 23, 2021.
http://hdl.handle.net/1969.1/3354.
MLA Handbook (7th Edition):
Pandey, Amit Nath. “Fault detection of multivariable system using its directional properties.” 2006. Web. 23 Apr 2021.
Vancouver:
Pandey AN. Fault detection of multivariable system using its directional properties. [Internet] [Masters thesis]. Texas A&M University; 2006. [cited 2021 Apr 23].
Available from: http://hdl.handle.net/1969.1/3354.
Council of Science Editors:
Pandey AN. Fault detection of multivariable system using its directional properties. [Masters Thesis]. Texas A&M University; 2006. Available from: http://hdl.handle.net/1969.1/3354
Texas A&M University
20.
Zhang, Junjie.
Practical Issues in Formation Control of Multi-Robot Systems.
Degree: PhD, Mechanical Engineering, 2010, Texas A&M University
URL: http://hdl.handle.net/1969.1/ETD-TAMU-2010-05-7886
► Considered in this research is a framework for effective formation control of multirobot systems in dynamic environments. The basic formation control involves two important considerations:…
(more)
▼ Considered in this research is a framework for effective formation control of multirobot
systems in dynamic environments. The basic formation control involves two important
considerations: (1) Real-time trajectory generation algorithms for distributed control
based on nominal agent models, and (2) robust tracking of reference trajectories under
model uncertainties.
Proposed is a two-layer hierarchical architecture for collectivemotion control ofmultirobot
nonholonomic systems. It endows robotic systems with the ability to simultaneously
deal with multiple tasks and achieve typical complex formation missions, such as collisionfree
maneuvers in dynamic environments, tracking certain desired trajectories, forming
suitable patterns or geometrical shapes, and/or varying the pattern when necessary.
The study also addresses real-time formation tracking of reference trajectories under
the presence of model uncertainties and proposes robust control laws such that over each
time interval any tracking errors due to system uncertainties are driven down to zero prior to
the commencement of the subsequent computation segment. By considering a class of nonlinear
systems with favorable finite-time convergence characteristics, sufficient conditions
for exponential finite-time stability are established and then applied to distributed formation
tracking controls. This manifests in the settling time of the controlled system being finite
and no longer than the predefined reference trajectory segment computing time interval,
thus making tracking errors go to zero by the end of the time horizon over which a segment
of the reference trajectory is generated. This way the next segment of the reference trajectory is properly initialized to go into the trajectory computation algorithm. Consequently
this could lead to a guarantee of desired multi-robot motion evolution in spite of system
uncertainties.
To facilitate practical implementation, communication among multi-agent systems is
considered to enable the construction of distributed formation control. Instead of requiring
global communication among all robots, a distributed communication algorithm is employed
to eliminate redundant data propagation, thus reducing energy consumption and
improving network efficiency while maintaining connectivity to ensure the convergence of
formation control.
Advisors/Committee Members: Jayasuriya, Suhada (advisor), Palazzolo, Alan (committee member), Kim, Won-jong (committee member), Song, Dezhen (committee member).
Subjects/Keywords: Formation Control; Multi-Robot Systems; Uncertainty; Finite-Time Stability; Robust Control; Time-Delay
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Zhang, J. (2010). Practical Issues in Formation Control of Multi-Robot Systems. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-2010-05-7886
Chicago Manual of Style (16th Edition):
Zhang, Junjie. “Practical Issues in Formation Control of Multi-Robot Systems.” 2010. Doctoral Dissertation, Texas A&M University. Accessed April 23, 2021.
http://hdl.handle.net/1969.1/ETD-TAMU-2010-05-7886.
MLA Handbook (7th Edition):
Zhang, Junjie. “Practical Issues in Formation Control of Multi-Robot Systems.” 2010. Web. 23 Apr 2021.
Vancouver:
Zhang J. Practical Issues in Formation Control of Multi-Robot Systems. [Internet] [Doctoral dissertation]. Texas A&M University; 2010. [cited 2021 Apr 23].
Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2010-05-7886.
Council of Science Editors:
Zhang J. Practical Issues in Formation Control of Multi-Robot Systems. [Doctoral Dissertation]. Texas A&M University; 2010. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2010-05-7886
Texas A&M University
21.
Ye, Dan.
Control of real-time multimedia applications in best-effort networks.
Degree: PhD, Mechanical Engineering, 2009, Texas A&M University
URL: http://hdl.handle.net/1969.1/ETD-TAMU-1157
► The increasing demand for real-time multimedia applications and the lack of quality of service (QoS) support in public best-effort or Internet Protocol (IP) networks has…
(more)
▼ The increasing demand for real-time multimedia applications and the lack
of quality of service (QoS) support in public best-effort or Internet Protocol (IP)
networks has prompted many researchers to propose improvements on the QoS of such
networks. This research aims to improve the QoS of real-time multimedia applications
in public best-effort networks, without modifying the core network infrastructure or
the existing codecs of the original media applications.
A source buffering control is studied based on a fluid model developed for a single
flow transported over a best-effort network while allowing for flow reversal. It is shown
that this control is effective for QoS improvement only when there is sufficient flow
reversal or packet reordering in the network.
An alternate control strategy based on predictive multi-path switching is studied
where only two paths are considered as alternate options. Initially, an emulation study
is performed, exploring the impact of path loss rate and traffic delay signal frequency
content on the proposed control. The study reveals that this control strategy provides
the best QoS improvement when the average comprehensive loss rates of the two paths
involved are between 5% and 15%, and when the delay signal frequency content is
around 0.5 Hz. Linear and nonlinear predictors are developed using actual network
data for use in predictive multi-path switching control. The control results show
that predictive path switching is better than no path switching, yet no one predictor developed is best for all cases studied. A voting based control strategy is proposed
to overcome this problem. The results show that the voting based control strategy
results in better performance for all cases studied. An actual voice quality test is
performed, proving that predictive path switching is better than no path switching.
Despite the improvements obtained, predictive path switching control has some
scalability problems and other shortcomings that require further investigation. If
there are more paths available to choose from, the increasing overhead in probing
traffic might become unacceptable. Further, if most of the VoIP flows on the Internet
use this control strategy, then the conclusions of this research might be different,
requiring modifications to the proposed approach. Further studies on these problems
are needed.
Advisors/Committee Members: Parlos, Alexander (advisor), Jayasuriya, Suhada (committee member), Kim, Won-jong (committee member), Sanchez-Sinencio, Edgar (committee member).
Subjects/Keywords: VoIP; QoS control; Internet modeling; predictive path switching.
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Ye, D. (2009). Control of real-time multimedia applications in best-effort networks. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-1157
Chicago Manual of Style (16th Edition):
Ye, Dan. “Control of real-time multimedia applications in best-effort networks.” 2009. Doctoral Dissertation, Texas A&M University. Accessed April 23, 2021.
http://hdl.handle.net/1969.1/ETD-TAMU-1157.
MLA Handbook (7th Edition):
Ye, Dan. “Control of real-time multimedia applications in best-effort networks.” 2009. Web. 23 Apr 2021.
Vancouver:
Ye D. Control of real-time multimedia applications in best-effort networks. [Internet] [Doctoral dissertation]. Texas A&M University; 2009. [cited 2021 Apr 23].
Available from: http://hdl.handle.net/1969.1/ETD-TAMU-1157.
Council of Science Editors:
Ye D. Control of real-time multimedia applications in best-effort networks. [Doctoral Dissertation]. Texas A&M University; 2009. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-1157
Texas A&M University
22.
Lan, Chen-Yang.
A novel feedback design method for mimo QFT with application to the X-29 flight control problem.
Degree: PhD, Mechanical Engineering, 2009, Texas A&M University
URL: http://hdl.handle.net/1969.1/ETD-TAMU-3006
► Quantitative Feedback Theory (QFT) method employs a two degree of freedom control configuration that includes a feedback controller and a prefilter in the feedforward path.…
(more)
▼ Quantitative Feedback Theory (QFT) method employs a two degree of freedom
control configuration that includes a feedback controller and a prefilter in the feedforward
path. When applied to multi-input multi-output (MIMO) systems, the QFT
method calls for a special decomposition of the MIMO system. Specifically, the MIMO
system is decomposed into multiple multi-input single-output (MISO) equivalent
systems, and is followed by the single-input single-output (SISO) QFT design of each
equivalent system. Depending on pole-zero structure of the equivalent SISO plants so
obtained, the QFT design may become unnecessarily difficult/conservative or even
infeasible. This situation is especially true for linear time invariant (LTI) systems with
non-minimum phase (NMP) zero(s) and unstable pole(s).
This unnecessary design difficulty and the challenge of dealing with MIMO
systems that have unstable poles and NMP transmission zeros in undesirable locations,
when MIMO QFT is considered, is investigated and addressed in this research. A new
MIMO QFT design methodology was developed using the generalized formulation. The
key idea of the generalized formulation is to utilize appropriate modifications at the plant input and/or the output to obtain a better conditioned plant that in turn can be used to
execute a standard MIMO QFT design. The formulation is based on a more general
control structure, where input and output transfer function matrices (TFM) are included
to provide additional degrees of freedom in the typical decentralised MIMO QFT
feedback structure, which facilitates the exploitation of directions in MIMO QFT
designs. The formulation captures existing design approaches for a fully populated
MIMO QFT controller design and provides for a directional design logic involving the
plant and controller alignment and the directional properties of their multivariable poles
and zeros. As a case in point Horowitz’s Singular-G design methodology is placed in the
context of this generalized formulation, and the Singular-G design for the X-29 is
analysed and redesigned using both non-sequential and sequential MIMO QFT
demonstrating its utility.
The results highlight a fundamental trade-off between multivariable controller
directions for stability and performance in classically formulated MIMO QFT design
methodologies, which elucidate the properties of Singular-G designed controllers for the
X-29 and validate the developed new MIMO QFT design method.
Advisors/Committee Members: Jayasuriya, Suhada (advisor), Bhattacharyya, Shankar P. (committee member), Kim, Won-jong (committee member), Parlos, Alexander (committee member).
Subjects/Keywords: QFT; MIMO; Control
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Lan, C. (2009). A novel feedback design method for mimo QFT with application to the X-29 flight control problem. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-3006
Chicago Manual of Style (16th Edition):
Lan, Chen-Yang. “A novel feedback design method for mimo QFT with application to the X-29 flight control problem.” 2009. Doctoral Dissertation, Texas A&M University. Accessed April 23, 2021.
http://hdl.handle.net/1969.1/ETD-TAMU-3006.
MLA Handbook (7th Edition):
Lan, Chen-Yang. “A novel feedback design method for mimo QFT with application to the X-29 flight control problem.” 2009. Web. 23 Apr 2021.
Vancouver:
Lan C. A novel feedback design method for mimo QFT with application to the X-29 flight control problem. [Internet] [Doctoral dissertation]. Texas A&M University; 2009. [cited 2021 Apr 23].
Available from: http://hdl.handle.net/1969.1/ETD-TAMU-3006.
Council of Science Editors:
Lan C. A novel feedback design method for mimo QFT with application to the X-29 flight control problem. [Doctoral Dissertation]. Texas A&M University; 2009. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-3006
Texas A&M University
23.
Bhattacharya, Aninda.
Flow control of real-time unicast multimedia applications in best-effort networks.
Degree: PhD, Mechanical Engineering, 2009, Texas A&M University
URL: http://hdl.handle.net/1969.1/ETD-TAMU-1553
► One of the fastest growing segments of Internet applications are real-time mul- timedia applications, like Voice over Internet Protocol (VoIP). Real-time multimedia applications use the…
(more)
▼ One of the fastest growing segments of Internet applications are real-time mul-
timedia applications, like Voice over Internet Protocol (VoIP). Real-time multimedia
applications use the User Datagram Protocol (UDP) as the transport protocol because
of the inherent conservative nature of the congestion avoidance schemes of Transmis-
sion Control Protocol (TCP). The e®ects of uncontrolled °ows on the Internet have
not yet been felt because UDP tra±c frequently constitutes only » 20% of the total
Internet tra±c. It is pertinent that real-time multimedia applications become better
citizens of the Internet, while at the same time deliver acceptable Quality of Service
(QoS).
Traditionally, packet losses and the increase in the end-to-end delay experienced
by some of the packets characterizes congestion in the network. These two signals
have been used to develop most known °ow control schemes. The current research
considers the °ow accumulation in the network as the signal for use in °ow control.
The most signi¯cant contribution of the current research is to propose novel end-
to-end °ow control schemes for unicast real-time multimedia °ows transmitting over
best-e®ort networks. These control schemes are based on predictive control of the
accumulation signal. The end-to-end control schemes available in the literature are
based on reactive control that do not take into account the feedback delay existing
between the sender and the receiver nor the forward delay in the °ow dynamics. The performance of the proposed control schemes has been evaluated using the
ns-2 simulation environment. The research concludes that active control of hard real-
time °ows delivers the same or somewhat better QoS as High Bit Rate (HBR, no
control), but with a lower average bit rate. Consequently, it helps reduce bandwidth
use of controlled real-time °ows by anywhere between 31:43% to 43:96%. Proposed
reactive control schemes deliver good QoS. However, they do not scale up as well as
the predictive control schemes. Proposed predictive control schemes are e®ective in
delivering good quality QoS while using up less bandwidth than even the reactive con-
trol schemes. They scale up well as more real-time multimedia °ows start employing
them.
Advisors/Committee Members: Parlos, Alexander G (advisor), Jayasuriya, Suhada (committee member), Kim, Won-Jong (committee member), Zhang, Xi (committee member).
Subjects/Keywords: Flow control; multimedia; unicast; best-effort networks
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Bhattacharya, A. (2009). Flow control of real-time unicast multimedia applications in best-effort networks. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-1553
Chicago Manual of Style (16th Edition):
Bhattacharya, Aninda. “Flow control of real-time unicast multimedia applications in best-effort networks.” 2009. Doctoral Dissertation, Texas A&M University. Accessed April 23, 2021.
http://hdl.handle.net/1969.1/ETD-TAMU-1553.
MLA Handbook (7th Edition):
Bhattacharya, Aninda. “Flow control of real-time unicast multimedia applications in best-effort networks.” 2009. Web. 23 Apr 2021.
Vancouver:
Bhattacharya A. Flow control of real-time unicast multimedia applications in best-effort networks. [Internet] [Doctoral dissertation]. Texas A&M University; 2009. [cited 2021 Apr 23].
Available from: http://hdl.handle.net/1969.1/ETD-TAMU-1553.
Council of Science Editors:
Bhattacharya A. Flow control of real-time unicast multimedia applications in best-effort networks. [Doctoral Dissertation]. Texas A&M University; 2009. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-1553
Texas A&M University
24.
Lee, Jaeyong.
Deployment and coverage maintenance in mobile sensor networks.
Degree: PhD, Mechanical Engineering, 2009, Texas A&M University
URL: http://hdl.handle.net/1969.1/ETD-TAMU-1564
► Deployment of mobile nodes in a region of interest is a critical issue in building a mobile sensor network because it affects cost and detection…
(more)
▼ Deployment of mobile nodes in a region of interest is a critical issue in building a mobile
sensor network because it affects cost and detection capabilities of the system. The deployment
of mobile sensors in essence is the movement of sensors from an initial position to a
final optimal location. Considerable attention has recently been given to this deployment
issue. Many of the distributed deployment schemes use the potential field method. In most
cases, the negative gradient of the potential function becomes the feedback control input
to a node. This assumes that the potential function is differentiable over the entire region.
This assumption is valid primarily when the topology of the network is fixed.
In this research, we analyze the stability of a network that uses piecewise smooth
potential functions. A gravitation-like force is proposed to deploy a group of agents and to
form a certain configuration. We use a nonsmooth version of the Lyapunov stability theory
and LaSalle’s invariance principle to show asymptotic stability of the network which is
governed by discontinuous dynamics.
We propose a hierarchical structure using potential fields for mobile sensor network
deployment. A group of mobile nodes first form a cluster using a potential field method
and then cluster heads are used to establish a hexagonal structure that employs a higher
level potential field.
We consider specifically the problem of deploying a mobile sensor network so that a
certain area coverage is realized and maintained. And we propose an algorithm for main taining the desired coverage that assumes the availability of a stochastic sensor model. The
model reflects the decline of the sensor accuracy as the distance increases from the sensor.
It is further assumed that each node’s sensor has a different sensing range to represent
sensor performance deterioration due to power decay. The network deployment scheme
combines artificial forces with individual sensor ranges. The validity and the effectiveness
of the proposed algorithm are compared to the conventional methods in simulations. Simulation
results confirm the effectiveness of the proposed algorithms with respect to a defined
performance metric.
Advisors/Committee Members: Jayasuriya, Suhada (advisor), Kim, Won-jong (committee member), Parlos, Alexander (committee member), Welch, Jennifer L. (committee member).
Subjects/Keywords: mobile sensor network; coverage; deployment
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Lee, J. (2009). Deployment and coverage maintenance in mobile sensor networks. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-1564
Chicago Manual of Style (16th Edition):
Lee, Jaeyong. “Deployment and coverage maintenance in mobile sensor networks.” 2009. Doctoral Dissertation, Texas A&M University. Accessed April 23, 2021.
http://hdl.handle.net/1969.1/ETD-TAMU-1564.
MLA Handbook (7th Edition):
Lee, Jaeyong. “Deployment and coverage maintenance in mobile sensor networks.” 2009. Web. 23 Apr 2021.
Vancouver:
Lee J. Deployment and coverage maintenance in mobile sensor networks. [Internet] [Doctoral dissertation]. Texas A&M University; 2009. [cited 2021 Apr 23].
Available from: http://hdl.handle.net/1969.1/ETD-TAMU-1564.
Council of Science Editors:
Lee J. Deployment and coverage maintenance in mobile sensor networks. [Doctoral Dissertation]. Texas A&M University; 2009. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-1564
Texas A&M University
25.
Wang, Lin.
Induction motor bearing fault detection using a sensorless approach.
Degree: PhD, Mechanical Engineering, 2009, Texas A&M University
URL: http://hdl.handle.net/1969.1/157905
► Continuous condition assessment of induction motors is very important due to its potential to reduce down-time and manpower needed in industry. Rolling element bearing faults…
(more)
▼ Continuous condition assessment of induction motors is very important due to
its potential to reduce down-time and manpower needed in industry. Rolling element
bearing faults result in more than 40% of all induction motor failures. Vibration
analysis has been utilized to detect bearing faults for years. However, vibration
sensors and expert vibration interpretation are expensive. This limitation prevents
widespread monitoring of continuous bearing conditions in induction motors, which
provides better performance compared to periodic monitoring, a typical practice for
motor bearing maintenance in industry. A strong motivation exists for finding a costeffective
approach for the detection of bearing faults. Motor terminal signals have
attracted much attention. However, not many papers in the literature address this
issue as it relates to bearing faults, because of the difficulties in effective detection.
In this research, an incipient bearing fault detection method for induction motors
is proposed based on the analysis of motor terminal voltages and currents. The basic
idea of this method is to detect changes in amplitude modulation between the spatial
harmonics caused by bearing faults and the supply fundamental frequency. This
amplitude modulation relationship can be isolated using the phase coupling property.
An Amplitude Modulation Detector (AMD), developed from higher order spectrum
estimation, correctly captures the phase coupling and isolates these modulation relationships.
In this research, in-situ bearing damage experiments are conducted so that the
accelerated life span of the bearing can be recorded and investigated. Experimental
results shown in this dissertation are based on different power supplies, load levels, VSI
control schemes, and motor operating conditions. Taking the mechanical vibration
indicator as a reference for fault detection, the proposed method is demonstrated to
be effective in detecting incipient bearing faults in induction motors. If motors are
operating at near steady state conditions, then experimental results show that the
bearing fault detection rate of the proposed approach is 100%, while no false alarms
are recorded.
Advisors/Committee Members: Parlos, Alexander G (advisor), Jayasuriya, Suhada (committee member), Kim, Won-jong (committee member), Sanchez-Sinencio, Edgar (committee member).
Subjects/Keywords: Induction Motor; Fault Detection; Bearing Fault; Sensorless; Electrical Signal Analysis; Power Supply
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Wang, L. (2009). Induction motor bearing fault detection using a sensorless approach. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/157905
Chicago Manual of Style (16th Edition):
Wang, Lin. “Induction motor bearing fault detection using a sensorless approach.” 2009. Doctoral Dissertation, Texas A&M University. Accessed April 23, 2021.
http://hdl.handle.net/1969.1/157905.
MLA Handbook (7th Edition):
Wang, Lin. “Induction motor bearing fault detection using a sensorless approach.” 2009. Web. 23 Apr 2021.
Vancouver:
Wang L. Induction motor bearing fault detection using a sensorless approach. [Internet] [Doctoral dissertation]. Texas A&M University; 2009. [cited 2021 Apr 23].
Available from: http://hdl.handle.net/1969.1/157905.
Council of Science Editors:
Wang L. Induction motor bearing fault detection using a sensorless approach. [Doctoral Dissertation]. Texas A&M University; 2009. Available from: http://hdl.handle.net/1969.1/157905
Texas A&M University
26.
Yang, Baozhong.
On the characteristics of fault-induced rotor-dynamic bifurcations and nonlinear responses.
Degree: PhD, Mechanical Engineering, 2004, Texas A&M University
URL: http://hdl.handle.net/1969.1/1135
► Rotor-dynamic stability is a very important subject impacting the design, control, maintenance, and operating safety and reliability of rotary mechanical systems. As rotor-dynamic nonlinearities are…
(more)
▼ Rotor-dynamic stability is a very important subject impacting the design, control, maintenance, and operating safety and reliability of rotary mechanical systems. As rotor-dynamic nonlinearities are significantly more prominent at higher rotary speeds, the demand for better and improved performance achievable through higher speeds has rendered the use of a linear approach for rotor-dynamic analysis both inadequate and ineffective. To establish the fundamental knowledge base necessary for addressing the need, it is essential that nonlinear rotor-dynamic responses indicative of the causes of nonlinearity, along with the bifurcated dynamic states of instability, be fully characterized. The objectives of the research are to study the various rotor-dynamic instabilities induced by crack breathing and bearing fluid film forces using a model rotor-bearing system and to investigate the applicability of the fundamental concept of instantaneous frequency for characterizing rotor-dynamic nonlinear responses. A comprehensive finite element model incorporating translational and rotational inertia, bending stiffness and gyroscopic moment is developed. The intrinsic modes extracted using the Empirical Mode Decomposition along with their instantaneous frequencies resolved using the Hilbert transform are applied to characterize the inception and progression of bifurcations suggestive of the changing rotor-dynamic state and impending instability. The dissertation presents and demonstrates an effective approach that integrates nonlinear rotor-dynamics, instantaneous time-frequency analysis, advanced notions of dynamic system diagnostics and numerical modeling applied to the detection and identification of sensitive variations indicative of a bifurcated dynamic state. All presented studies on rotor response subjected to various system configurations and ranges of parameters show good agreements with published results. Under the influence of crack opening, the rotor-bearing model system displays transitional behaviors typical of a nonlinear dynamic system, going from periodic to period-doubling, chaotic to eventual failure. When film forces are also considered, the model system demonstrates very different behaviors and failures from different settings and ranges of control parameters. As a result, a dynamic failure curve differentiating zones of stability and bifurcated instability from zones of dynamic failure is constructed and proposed as an alternative to the traditional stability chart. Observations and results such as these have important practical implications on the design and safe operation of high performance rotary machinery.
Advisors/Committee Members: Chan, Andrew K. (advisor), Suh, Chii-Der S. (advisor), Parlos, Alexander G. (committee member), Jayasuriya, Suhada (committee member).
Subjects/Keywords: rotordynamics; bifurcation; nonlinear responses; nonlinear instability
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Yang, B. (2004). On the characteristics of fault-induced rotor-dynamic bifurcations and nonlinear responses. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/1135
Chicago Manual of Style (16th Edition):
Yang, Baozhong. “On the characteristics of fault-induced rotor-dynamic bifurcations and nonlinear responses.” 2004. Doctoral Dissertation, Texas A&M University. Accessed April 23, 2021.
http://hdl.handle.net/1969.1/1135.
MLA Handbook (7th Edition):
Yang, Baozhong. “On the characteristics of fault-induced rotor-dynamic bifurcations and nonlinear responses.” 2004. Web. 23 Apr 2021.
Vancouver:
Yang B. On the characteristics of fault-induced rotor-dynamic bifurcations and nonlinear responses. [Internet] [Doctoral dissertation]. Texas A&M University; 2004. [cited 2021 Apr 23].
Available from: http://hdl.handle.net/1969.1/1135.
Council of Science Editors:
Yang B. On the characteristics of fault-induced rotor-dynamic bifurcations and nonlinear responses. [Doctoral Dissertation]. Texas A&M University; 2004. Available from: http://hdl.handle.net/1969.1/1135
Texas A&M University
27.
Xu, Hao.
Synthesis and design of PID controllers.
Degree: PhD, Electrical Engineering, 2005, Texas A&M University
URL: http://hdl.handle.net/1969.1/1480
► controllers for discrete-time systems and time-delayed systems. By using bilinear transformation and orthogonal transformation, earlier research results obtained in the continuous-time case are extended to…
(more)
▼ controllers for discrete-time systems and time-delayed systems. By using bilinear
transformation and orthogonal transformation, earlier research results obtained in
the continuous-time case are extended to discrete-time situation. The complete set of
stabilizing PID controllers for the discrete-time systems is thus obtained. Moreover,
this set remains to be a union of convex sets when one particular parameter is fixed.
Thus a method to design robust and non-fragile digital PID controllers is proposed
by following a similar design procedure for the continuous-time systems. In order to
find the stabilizing controller set for systems with time-delays, the relationship between
the Nyquist Criterion and Pontryagins theory is investigated. The conditions
under which one can correctly apply the Nyquist Criterion to time-delayed systems
are derived. Then, the complete set of stabilizing PID controllers for arbitrary order
LTI systems with time-delay up to a given value is obtained. Furthermore, the stability
issue of a system with fixed-delay is also studied and a formula which provides
complete knowledge of the distribution of the closed-loop poles is presented. Based
on this formula, stabilizing P and PI controller sets for the system with fixed-delay
can be computed.
Advisors/Committee Members: Datta, Aniruddha (advisor), Halverson, Don R. (committee member), Bhattacharyya, Shankar P. (committee member), Jayasuriya, Suhada (committee member).
Subjects/Keywords: PID; LTI; discrete-time; time-delay; stabilization
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Xu, H. (2005). Synthesis and design of PID controllers. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/1480
Chicago Manual of Style (16th Edition):
Xu, Hao. “Synthesis and design of PID controllers.” 2005. Doctoral Dissertation, Texas A&M University. Accessed April 23, 2021.
http://hdl.handle.net/1969.1/1480.
MLA Handbook (7th Edition):
Xu, Hao. “Synthesis and design of PID controllers.” 2005. Web. 23 Apr 2021.
Vancouver:
Xu H. Synthesis and design of PID controllers. [Internet] [Doctoral dissertation]. Texas A&M University; 2005. [cited 2021 Apr 23].
Available from: http://hdl.handle.net/1969.1/1480.
Council of Science Editors:
Xu H. Synthesis and design of PID controllers. [Doctoral Dissertation]. Texas A&M University; 2005. Available from: http://hdl.handle.net/1969.1/1480
Texas A&M University
28.
Sugathevan, Suranthiran.
Nonlinear and distributed sensory estimation.
Degree: PhD, Mechanical Engineering, 2005, Texas A&M University
URL: http://hdl.handle.net/1969.1/2246
► Methods to improve performance of sensors with regard to sensor nonlinearity, sensor noise and sensor bandwidths are investigated and new algorithms are developed. The necessity…
(more)
▼ Methods to improve performance of sensors with regard to sensor nonlinearity, sensor noise and sensor bandwidths are investigated and new algorithms are developed. The necessity of the proposed research has evolved from the ever-increasing need for greater precision and improved reliability in sensor measurements. After describing the current state of the art of sensor related issues like nonlinearity and bandwidth, research goals are set to create a new trend on the usage of sensors. We begin the investigation with a detailed distortion analysis of nonlinear sensors. A need for efficient distortion compensation procedures is further justified by showing how a slight deviation from the linearity assumption leads to a very severe distortion in time and in frequency domains. It is argued that with a suitable distortion compensation technique the danger of having an infinite bandwidth nonlinear sensory operation, which is dictated by nonlinear distortion, can be avoided. Several distortion compensation techniques are developed and their performance is validated by simulation and experimental results. Like any other model-based technique, modeling errors or model uncertainty affects performance of the proposed scheme, this leads to the innovation of robust signal reconstruction. A treatment for this problem is given and a novel technique, which uses a nominal model instead of an accurate model and produces the results that are robust to model uncertainty, is developed. The means to attain a high operating bandwidth are developed by utilizing several low bandwidth pass-band sensors. It is pointed out that instead of using a single sensor to measure a high bandwidth signal, there are many advantages of using an array of several pass-band sensors. Having shown that employment of sensor arrays is an economic incentive and practical, several multi-sensor fusion schemes are developed to facilitate their implementation. Another aspect of this dissertation is to develop means to deal with outliers in sensor measurements. As fault sensor data detection is an essential element of multi-sensor network implementation, which is used to improve system reliability and robustness, several sensor scheduling configurations are derived to identify and to remove outliers.
Advisors/Committee Members: Jayasuriya, Suhada (advisor), Parlos, Alexander G. (committee member), Bhattacharyya, Shankar P. (committee member), Kim, Won-jong (committee member).
Subjects/Keywords: Nonlinear Sensors; Sensor Arrays; Sensor Fusion; Signal Processing; Control Systems
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Sugathevan, S. (2005). Nonlinear and distributed sensory estimation. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/2246
Chicago Manual of Style (16th Edition):
Sugathevan, Suranthiran. “Nonlinear and distributed sensory estimation.” 2005. Doctoral Dissertation, Texas A&M University. Accessed April 23, 2021.
http://hdl.handle.net/1969.1/2246.
MLA Handbook (7th Edition):
Sugathevan, Suranthiran. “Nonlinear and distributed sensory estimation.” 2005. Web. 23 Apr 2021.
Vancouver:
Sugathevan S. Nonlinear and distributed sensory estimation. [Internet] [Doctoral dissertation]. Texas A&M University; 2005. [cited 2021 Apr 23].
Available from: http://hdl.handle.net/1969.1/2246.
Council of Science Editors:
Sugathevan S. Nonlinear and distributed sensory estimation. [Doctoral Dissertation]. Texas A&M University; 2005. Available from: http://hdl.handle.net/1969.1/2246
Texas A&M University
29.
Hu, Tiejun.
Design and control of a 6-Degree-of-Freedom levitated positioner with high precision.
Degree: PhD, Mechanical Engineering, 2005, Texas A&M University
URL: http://hdl.handle.net/1969.1/2360
► This dissertation presents a high-precision positioner with a novel superimposed concentrated-field permanent-magnet matrix. This extended-range multi-axis positioner can generate all 6-DOF (degree-of-freedom) motions with only…
(more)
▼ This dissertation presents a high-precision positioner with a novel superimposed
concentrated-field permanent-magnet matrix. This extended-range multi-axis positioner can
generate all 6-DOF (degree-of-freedom) motions with only a single moving part. It is actuated
by three planar levitation motors, which are attached on the bottom of the moving part. Three
aerostatic bearings are used to provide the suspension force against the gravity for the system.
The dynamic model of the system is developed and analyzed. And several control techniques
including SISO (single input and single output) and MIMO (multi inputs and multi outputs)
controls are discussed in the dissertation. The positioner demonstrates a position resolution of 20
nm and position noise of 10 nm rms in x and y and 15 nm rms in z. The angular resolution
around the x-, y-, and z-axes is in sub-microradian order. The planar travel range is 160 mm ??
160 mm, and the maximum velocity achieved is 0.5
m/s at a 5-
m/s2 acceleration, which can
enhance the throughput in precision manufacturing. Various experimental results are presented in
this dissertation to demonstrate the positioner??s capability of accurately tracking any planar
trajectories. Those experimental results verified the potential utility of this 6-DOF high-precision
positioner in precision manufacturing and factory automation.
Advisors/Committee Members: Kim, Won-jong (advisor), Jayasuriya, Suhada (committee member), Parlos, Alexander (committee member), Toliyat, Hamid A. (committee member).
Subjects/Keywords: high precision motion control; permanent magnet synchronous planar motor; nano-positioning
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Hu, T. (2005). Design and control of a 6-Degree-of-Freedom levitated positioner with high precision. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/2360
Chicago Manual of Style (16th Edition):
Hu, Tiejun. “Design and control of a 6-Degree-of-Freedom levitated positioner with high precision.” 2005. Doctoral Dissertation, Texas A&M University. Accessed April 23, 2021.
http://hdl.handle.net/1969.1/2360.
MLA Handbook (7th Edition):
Hu, Tiejun. “Design and control of a 6-Degree-of-Freedom levitated positioner with high precision.” 2005. Web. 23 Apr 2021.
Vancouver:
Hu T. Design and control of a 6-Degree-of-Freedom levitated positioner with high precision. [Internet] [Doctoral dissertation]. Texas A&M University; 2005. [cited 2021 Apr 23].
Available from: http://hdl.handle.net/1969.1/2360.
Council of Science Editors:
Hu T. Design and control of a 6-Degree-of-Freedom levitated positioner with high precision. [Doctoral Dissertation]. Texas A&M University; 2005. Available from: http://hdl.handle.net/1969.1/2360
Texas A&M University
30.
Verma, Shobhit.
Development of novel high-performance six-axis magnetically levitated instruments for nanoscale applications.
Degree: PhD, Mechanical Engineering, 2005, Texas A&M University
URL: http://hdl.handle.net/1969.1/2602
► This dissertation presents two novel 6-axis magnetic-levitation (maglev) stages that are capable of nanoscale positioning. These stages have very simple and compact structure that is…
(more)
▼ This dissertation presents two novel 6-axis magnetic-levitation (maglev) stages that are capable of nanoscale positioning. These stages have very simple and compact structure that is advantageous to meet requirements in the next-generation nanomanufacturing. The 6-axis motion generation is accomplished by the minimum number of actuators and sensors. The first-generation maglev stage is capable of generating translation of 300 ??
m in x, y and z, and rotation of 3 mrad about the three orthogonal axes. The stage demonstrates position resolution better than 5 nm rms and position noise less than 2 nm rms. It has a light moving-part mass of 0.2126 kg. The total power consumption by all the actuators is only around a watt. Experimental results show that the stage can carry, orient, and precisely position an additional payload as heavy as 0.3 kg. The second-generation maglev stage is capable of positioning at the resolution of a few nanometers over a planar travel range of several millimeters. A novel actuation scheme was developed for the compact design of this stage that enables 6-axis force generation with just 3permanent-magnet pieces. Electromagnetic forces were calculated and experimentally verified. The complete design and construction of the second-generation maglev stage was performed. All the mechanical part and assembly fixtures were designed and fabricated at the mechanical engineering machine shop. The single moving part is modeled as a pure mass due to the negligible effect of the magnetic spring and damping. Classical as well as advanced controllers were designed and implemented for closed-loop feedback control. A nonlinear model of the force was developed and applied to cancel the nonlinearity of the actuators over the large travel range. Various experiments were conducted to test positioning, loading, and vibration-isolation capabilities. This maglev stage has a moving-part mass of 0.267 kg. Its position resolution is 4 nm over a travel range of 5 ?? 5 mm in the x-y plane. Its actuators are designed to carry and precisely position an additional payload of 2 kg. Its potential applications include semiconductor manufacturing, micro-fabrication and assembly, nanoscale profiling, and nano-indentation.
Advisors/Committee Members: Kim, Won-jong (advisor), Bhattacharyya, Shankar P. (committee member), Jayasuriya, Suhada (committee member), Parlos, Alexander (committee member).
Subjects/Keywords: nanopositioning; magnetic levitation; feedback control
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Verma, S. (2005). Development of novel high-performance six-axis magnetically levitated instruments for nanoscale applications. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/2602
Chicago Manual of Style (16th Edition):
Verma, Shobhit. “Development of novel high-performance six-axis magnetically levitated instruments for nanoscale applications.” 2005. Doctoral Dissertation, Texas A&M University. Accessed April 23, 2021.
http://hdl.handle.net/1969.1/2602.
MLA Handbook (7th Edition):
Verma, Shobhit. “Development of novel high-performance six-axis magnetically levitated instruments for nanoscale applications.” 2005. Web. 23 Apr 2021.
Vancouver:
Verma S. Development of novel high-performance six-axis magnetically levitated instruments for nanoscale applications. [Internet] [Doctoral dissertation]. Texas A&M University; 2005. [cited 2021 Apr 23].
Available from: http://hdl.handle.net/1969.1/2602.
Council of Science Editors:
Verma S. Development of novel high-performance six-axis magnetically levitated instruments for nanoscale applications. [Doctoral Dissertation]. Texas A&M University; 2005. Available from: http://hdl.handle.net/1969.1/2602
◁ [1] [2] ▶
. 
Open Access Theses and Dissertations
