The thesis develops a trajectory planner which operates in a formula racing scenario. The proposed trajectory planner gives time-optimal off-road trajectory planning solutions and generates sequences of control signals for the vehicle to follow the trajectory. Outputs of the trajectory planner are time-optimal trajectory, steering angle, resultant force of brake and throttle. The trajectory planner is designed to have two modes, the Exploring mode which is based on Rapidly-exploring Random Tree (RRT), and the optimization mode which is built upon optimal Rapidly-exploring random tree (RRT*). The exploring mode can generate a valid and safe trajectory in real time, but the solution is not optimal; optimization mode gives optimal trajectories but it can only do offline planning. The system structure makes it possible that the exploring mode keeps running while the optimization mode runs in the background; once the optimization process is complete, the vehicle could then follow the optimal trajectory. A local trajectory planning method which considers the constraint of off-road vehicle dynamics is designed and integrated in the planner. System performance is evaluated by simulations on a racing track. Many aspects including time optimality, vehicle stability have been taken into account. A new, fast, local steering method has been proposed; the method generates trajectory based on random input. By a more efficient implementation of the planner in the future, for example by using parallel computing, the optimization mode is promising for real-time trajectory generation. ; Detta examensarbete utvecklar en trajektoriegenerering som baseras på ett Formula racing scenario. Den föreslagna trajektoriegenerering ger en tidsoptimal off-road-lösning och medför sekventiella kontrollsignaler till fordonen att följa trajektorien. Utsignaler från trajektoriegenerering är den tidsoptimal trajektorien, styrvinkel och motsvarande kraft for broms och gaspådrag. Trajektoriegenerering är designad med två funktioner, utforskningsläget ...
Trajectory Planning for Off-road Autonomous Driving
2018-01-01
Theses
Electronic Resource
English
DDC: | 629 |
FOCUSED TRAJECTORY PLANNING FOR AUTONOMOUS ON-ROAD DRIVING
British Library Conference Proceedings | 2013
|SAGE Publications | 2021
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