Advanced search options

Advanced Search Options 🞨

Browse by author name (“Author name starts with…”).

Find ETDs with:

in
/  
in
/  
in
/  
in

Written in Published in Earliest date Latest date

Sorted by

Results per page:

Sorted by: relevance · author · university · dateNew search

You searched for subject:(Online Trajectory Generation). Showing records 1 – 3 of 3 total matches.

Search Limiters

Last 2 Years | English Only

No search limiters apply to these results.

▼ Search Limiters


University of California – Berkeley

1. Tsai, Chi-Shen. Online Trajectory Generation for Robot Manipulators in Dynamic Environment  – An Optimization-based Approach.

Degree: Mechanical Engineering, 2014, University of California – Berkeley

Interest in robot manipulators interacting with dynamic environments has been continuously growing because of the increasing demand for industrial robot collaboration. Human-robot collaboration and robot-robot collaboration are the two scenarios of robot collaboration that have generally been considered. The difficulties of such applications may be described from two perspectives: a good perception of environment and a proper algorithm to react to the dynamic environment for the robot manipulators. Online trajectory generation is one of the approaches for robot reaction. In the generation of the trajectory, the transformation between joint space and task space is necessary since the sensor measurement of the environment is in task space and the trajectory of the robot manipulator is in joint space. The transformation needs to be done online in a dynamic environment and hence easily results in an exponential increase of the computational load.This dissertation proposes a safety index and the associated robot safety system in order to assess and ensure the safety of the agent in the collaboration scenarios. The agent could be a human worker in human-robot collaboration or another robot in robot-robot collaboration. In the robot safety system, the online trajectory generation algorithm is formulated in the optimization-based trajectory planning framework. The safety index is evaluated using the ellipsoid coordinates attached to the robot links that represents the distance between the robot manipulator and the agent. To account for the inertial effect, the momentum of therobot links are projected onto the coordinates to generate additional measures of safety. The safety index is used as a constraint in the formulation of the optimization problem so that a collision-free trajectory within a finite time horizon is generated online iteratively for the robot to move toward the desired position. To reduce the computational load for real-time implementation, the formulated optimization problem is further approximated by a quadratic problem. Moreover, a heuristic strategy is proposed to select the active constraints for the next iteration so as to further reduce the computational load. The safety index andthe proposed online trajectory generation algorithm are simulated and validated in both a two-link planar robot and a seven-DOF robot in human-robot collaboration and robot-robot collaboration. Simulation results show that the proposed algorithm and robot safety system are capable of generating collision-free and smooth trajectories online.The proposed algorithm has been extended to consider measurement noise in the agent information. Two possible approaches have been proposed for handling zero-mean Gaussian noise in the agent information.

Subjects/Keywords: Mechanical engineering; obstacle avoidance; online trajectory generation; Optimization

Record DetailsSimilar RecordsGoogle PlusoneFacebookTwitterCiteULikeMendeleyreddit

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Tsai, C. (2014). Online Trajectory Generation for Robot Manipulators in Dynamic Environment  – An Optimization-based Approach. (Thesis). University of California – Berkeley. Retrieved from http://www.escholarship.org/uc/item/3x02b7x5

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Tsai, Chi-Shen. “Online Trajectory Generation for Robot Manipulators in Dynamic Environment  – An Optimization-based Approach.” 2014. Thesis, University of California – Berkeley. Accessed January 21, 2021. http://www.escholarship.org/uc/item/3x02b7x5.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Tsai, Chi-Shen. “Online Trajectory Generation for Robot Manipulators in Dynamic Environment  – An Optimization-based Approach.” 2014. Web. 21 Jan 2021.

Vancouver:

Tsai C. Online Trajectory Generation for Robot Manipulators in Dynamic Environment  – An Optimization-based Approach. [Internet] [Thesis]. University of California – Berkeley; 2014. [cited 2021 Jan 21]. Available from: http://www.escholarship.org/uc/item/3x02b7x5.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Tsai C. Online Trajectory Generation for Robot Manipulators in Dynamic Environment  – An Optimization-based Approach. [Thesis]. University of California – Berkeley; 2014. Available from: http://www.escholarship.org/uc/item/3x02b7x5

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation


University of Lund

2. Ghazaei, Mahdi. On Trajectory Generation for Robots.

Degree: 2016, University of Lund

A fundamental problem in robotics is the generation of motion for a task. How to translate a task to a set of movements is a non-trivial problem. The complexity of the task, the capabilities of the robot, and the desired performance, affect all aspects of the trajectory; the sequence of movements, the path, and the course of motion as a function of time.This thesis is about trajectory generation and advances the state of the art in several directions. Special attention to trajectories in constrained situations when interaction forces are involved is paid. We bring a control perspective to trajectory generation and propose novel solutions for online trajectory generation with a rapid response to sensor inputs. We formulate and find optimal trajectories for various problems, closing the gap between path planning and trajectory generation. The inverse problem of finding the control signal corresponding to a desired trajectory is investigated and we extend the applicability of an existing algorithm to a broader class of problems.To collect human-generated trajectories involving force interactions, we propose a method to join two robotic manipulators to form a haptic interface for task demonstration. Furthermore, fast algorithms for fixed-time point-to-point trajectory generation are investigated. More importantly, two optimal closed-loop trajectory generation methods are proposed. We derive an optimal controller for the fixed-time trajectory-generation problem with a minimum-jerk cost functional. The other method is based on Model Predictive Control, which allows a more generic form of system dynamics and constraints. In addition, a ball-and-finger system is modeled for studying trajectory generation where interaction plays an important role. Efficient movements for rotating the ball are numerically computed and simulated.Iterative Learning Control (ILC) finds a proper control signal for obtaining a desired trajectory. We derive frequency-domain criteria for the convergence of linear ILC on finite-time intervals that are less restrictive than existing ones in the literature.

Subjects/Keywords: Robotics; Control Engineering; Haptic Interface; Fixed-Time Point-to-Point Trajectory Generation; Online Trajectory Generation; Dynamic Simulation and Optimization; Dynamics with Varying Contacts; Iterative Learning Control

Record DetailsSimilar RecordsGoogle PlusoneFacebookTwitterCiteULikeMendeleyreddit

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Ghazaei, M. (2016). On Trajectory Generation for Robots. (Doctoral Dissertation). University of Lund. Retrieved from https://lup.lub.lu.se/record/a17ad6f3-1e6b-4209-ae9f-92a6d80ed994 ; https://portal.research.lu.se/ws/files/17350248/thesis_mahdi_v161115.pdf

Chicago Manual of Style (16th Edition):

Ghazaei, Mahdi. “On Trajectory Generation for Robots.” 2016. Doctoral Dissertation, University of Lund. Accessed January 21, 2021. https://lup.lub.lu.se/record/a17ad6f3-1e6b-4209-ae9f-92a6d80ed994 ; https://portal.research.lu.se/ws/files/17350248/thesis_mahdi_v161115.pdf.

MLA Handbook (7th Edition):

Ghazaei, Mahdi. “On Trajectory Generation for Robots.” 2016. Web. 21 Jan 2021.

Vancouver:

Ghazaei M. On Trajectory Generation for Robots. [Internet] [Doctoral dissertation]. University of Lund; 2016. [cited 2021 Jan 21]. Available from: https://lup.lub.lu.se/record/a17ad6f3-1e6b-4209-ae9f-92a6d80ed994 ; https://portal.research.lu.se/ws/files/17350248/thesis_mahdi_v161115.pdf.

Council of Science Editors:

Ghazaei M. On Trajectory Generation for Robots. [Doctoral Dissertation]. University of Lund; 2016. Available from: https://lup.lub.lu.se/record/a17ad6f3-1e6b-4209-ae9f-92a6d80ed994 ; https://portal.research.lu.se/ws/files/17350248/thesis_mahdi_v161115.pdf

3. Desormeaux, Kevin. Temporal models of motions and forces for Human-Robot Interactive manipulation : Modèles temporels du mouvement et des forces pour la manipulation Interactive Homme-Robot.

Degree: Docteur es, Robotique, Informatique, 2019, Université Toulouse III – Paul Sabatier

L'intérêt pour la robotique a débuté dans les années 70 et depuis les robots n'ont cessé de remplacer les humains dans l'industrie. L'automatisation à outrance n'apporte cependant pas que des avantages, car elle nécessite des environnements parfaitement contrôlés et la reprogrammation d'une tâche est longue et fastidieuse. Le besoin accru d'adaptabilité et de ré-utilisabilité des systèmes d'assemblage force la robotique à se révolutionner en amenant notamment l'homme et le robot à interagir. Ce nouveau type de collaboration permet de combiner les forces respectives des humains et des robots. Cependant l'homme ne pourra être inclus en tant qu'agent actif dans ces nouveaux espaces de travail collaboratifs que si l'on dispose de robots sûrs, intuitifs et facilement reprogrammables. C'est à la lumière de ce constat qu'on peut deviner le rôle crucial de la génération de mouvement pour les robots de demain. Pour que les humains et les robots puissent collaborer, ces derniers doivent générer des mouvements sûrs afin de garantir la sécurité de l'homme tant physique que psychologique. Les trajectoires sont un excellent modèle pour la génération de mouvements adaptés aux robots collaboratifs, car elles offrent une description simple et précise de l'évolution du mouvement. Les trajectoires dîtes souples sont bien connues pour générer des mouvements sûrs et confortables pour l'homme. Dans cette thèse nous proposons un algorithme de génération de trajectoires temps-réel basé sur des séquences de segments de fonctions polynomiales de degré trois pour construire des trajectoires souples. Ces trajectoires sont construites à partir de conditions initiales et finales arbitraires, une condition nécessaire pour que les robots soient capables de réagir instantanément à des événements imprévus. L'approche basée sur un modèle à jerk-contraint offre des solutions orientées performance: les trajectoires sont optimales en temps sous contraintes de sécurité. Ces contraintes de sécurité sont des contraintes cinématiques qui dépendent de la tâche et du contexte et doivent être spécifiées. Pour guider le choix de ces contraintes, nous avons étudié le rôle de la cinématique dans la définition des propriétés ergonomiques du mouvement.[...]

It was in the 70s when the interest for robotics really emerged. It was barely half a century ago, and since then robots have been replacing humans in the industry. This robot-oriented solution doesn't come without drawbacks as full automation requires time-consuming programming as well as rigid environments. With the increased need for adaptability and reusability of assembly systems, robotics is undergoing major changes and see the emergence of a new type of collaboration between humans and robots. Human-Robot collaboration get the best of both world by combining the respective strengths of humans and robots. But, to include the human as an active agent in these new collaborative workspaces, safe and flexible robots are required. It is in this context that we can apprehend the crucial role of motion…

Advisors/Committee Members: Sidobre, Daniel (thesis director).

Subjects/Keywords: Génération de trajectoires en temps-réel; Interaction homme-robot; Contrôle réactif de trajectoires; Trajectoires souples; Ergonomie du mouvement; Online Trajectory Generation; Human-Robot Interaction; Reactive Trajectory Control; Smooth Trajectories; Motion Ergonomics

Record DetailsSimilar RecordsGoogle PlusoneFacebookTwitterCiteULikeMendeleyreddit

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Desormeaux, K. (2019). Temporal models of motions and forces for Human-Robot Interactive manipulation : Modèles temporels du mouvement et des forces pour la manipulation Interactive Homme-Robot. (Doctoral Dissertation). Université Toulouse III – Paul Sabatier. Retrieved from http://www.theses.fr/2019TOU30221

Chicago Manual of Style (16th Edition):

Desormeaux, Kevin. “Temporal models of motions and forces for Human-Robot Interactive manipulation : Modèles temporels du mouvement et des forces pour la manipulation Interactive Homme-Robot.” 2019. Doctoral Dissertation, Université Toulouse III – Paul Sabatier. Accessed January 21, 2021. http://www.theses.fr/2019TOU30221.

MLA Handbook (7th Edition):

Desormeaux, Kevin. “Temporal models of motions and forces for Human-Robot Interactive manipulation : Modèles temporels du mouvement et des forces pour la manipulation Interactive Homme-Robot.” 2019. Web. 21 Jan 2021.

Vancouver:

Desormeaux K. Temporal models of motions and forces for Human-Robot Interactive manipulation : Modèles temporels du mouvement et des forces pour la manipulation Interactive Homme-Robot. [Internet] [Doctoral dissertation]. Université Toulouse III – Paul Sabatier; 2019. [cited 2021 Jan 21]. Available from: http://www.theses.fr/2019TOU30221.

Council of Science Editors:

Desormeaux K. Temporal models of motions and forces for Human-Robot Interactive manipulation : Modèles temporels du mouvement et des forces pour la manipulation Interactive Homme-Robot. [Doctoral Dissertation]. Université Toulouse III – Paul Sabatier; 2019. Available from: http://www.theses.fr/2019TOU30221

.