Delft University of Technology
Berger, Niels (author).
Lane Change Path Planning: with State-Dependent Safety Constraints.
Degree: 2018, Delft University of Technology
In the past years a number of SAE level 2 driving automation systems have come available in commercial vehicles. An example is Volvo's Pilot Assist, which provides a more comfortable journey for the driver as certain parts of the dynamic driving task are taken away, but it still requires the driver to be attentive in order to supervise the system and resume vehicle operation if necessary. Car manufacturers and high-tech companies all around the world are working on the development of an Automated Driving System (ADS) of level 3 or higher where the driver does not need to supervise, but have so far not been able to introduce any to the public. Operating a vehicle on an empty highway is relatively easy, but roads are getting more and more congested so dense traffic driving needs to be accounted for as well. Unsupervised driving does not only require that a system itself operates the vehicle correctly, but requires that it is able to cope with mistakes of other drivers. In order to take these into account as well as other unpredictable events, current driving automation systems tend to adopt large longitudinal margins with respect to surrounding traffic to use their ability to brake to avoid a collision. In dense traffic situations this conservative behaviour prohibits the ADS from making lane changes. This thesis was setup in cooperation with Volvo Cars / Zenuity to develop a lane change path planning algorithm that can plan active lane changes in dense traffic, by pushing into a gap without compromising the ability to avoid a possible collision. Earlier work at Volvo suggested considering the ability of a vehicle to not only brake, but also to make an evasive maneuver. If an evasion maneuver is available the necessary safety margins are reduced considerably compared to a `braking-only' scenario. In this work, the evasive maneuver was modeled and a constraint formulation was developed that if met, guarantees the availability of the designed evasion maneuver. This constraint translates to a state-dependent safety zone which the ADS should keep the vehicle clear off at all times. Model Predictive Control allows the implementation of such a safety zone by considering it as a constraint on the optimisation, guaranteeing that an evasion maneuver is available along any point on the prediction horizon. This negates the necessity to plan all possible evasion maneuvers separately, and it was therefore chosen as the path planning method. Implementation of the safety zone constraint on multiple surrounding vehicles, spread over multiple lanes in a Model Predictive Control framework, together with the requirements of being able to overtake other vehicles within the prediction horizon, necessitated the development of a novel 3-step algorithm. In this algorithm three Optimal Control Problems are solved consecutively to plan a path which positions the ego-vehicle optimally in the targeted gap without breaching the safety zones. To be able to implement the algorithm in…
Advisors/Committee Members: Keviczky, Tamas (mentor), Shyrokau, Barys (graduation committee), Baldi, Simone (graduation committee), Brännstrom, Mattias (graduation committee), Delft University of Technology (degree granting institution).
Subjects/Keywords: Automated Drving Systems; Model Predictive Control; Nonlinear; Lane Change; Autonomous driving; Self-driving car; Automated driving; Merging
to Zotero / EndNote / Reference
APA (6th Edition):
Berger, N. (. (2018). Lane Change Path Planning: with State-Dependent Safety Constraints. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:03aa26dd-e7e6-4ebb-9cd3-def3e169526f
Chicago Manual of Style (16th Edition):
Berger, Niels (author). “Lane Change Path Planning: with State-Dependent Safety Constraints.” 2018. Masters Thesis, Delft University of Technology. Accessed April 16, 2021.
MLA Handbook (7th Edition):
Berger, Niels (author). “Lane Change Path Planning: with State-Dependent Safety Constraints.” 2018. Web. 16 Apr 2021.
Berger N(. Lane Change Path Planning: with State-Dependent Safety Constraints. [Internet] [Masters thesis]. Delft University of Technology; 2018. [cited 2021 Apr 16].
Available from: http://resolver.tudelft.nl/uuid:03aa26dd-e7e6-4ebb-9cd3-def3e169526f.
Council of Science Editors:
Berger N(. Lane Change Path Planning: with State-Dependent Safety Constraints. [Masters Thesis]. Delft University of Technology; 2018. Available from: http://resolver.tudelft.nl/uuid:03aa26dd-e7e6-4ebb-9cd3-def3e169526f