Abstract:

A real-time motion planning algorithm based on initiative optimization was developed for the motion planning of autonomous bus to achieve its real-time, comfort and safety. A Station-Lateral coordinate system was established, regarding the lane center line as the reference line. Cost functions were proposed considering indicators such as comfort. The sampling space was limited to ensure real-time performance. A better combination of lateral offset and longitudinal velocity was generated as the basic trajectory. The kinematics model of autonomous bus was used to generate trajectory, which optimized the trajectory quality initiatively. The virtual simulation test and the real vehicle test were implemented. The results show that the algorithm calculation time is 48.3 ms on average, on the low-power embedded computing platform of the vehicle; the real-time performance meets the typical urban road conditions. the standard deviation of trajectory curvature change rate by using the algorithm is reduced by 18.35% on average compared with that by using single sampling method. Therefore, it makes autonomous bus being better comfort and safety.

Key words: autonomous driving, autonomous buses, motion planning, trajectory generation, comfort and safety