Abstract: In view of problem in all possible uncertain behavior of vehicle unable existed by the traditional path planning algorithm, a modeling method was proposed which deemed a moving vehicle as a hybrid system switching dynamically between continuous and discrete mode, modeled an optimal trajectory for vehicle obstacle avoidance by using a single security target location, and built a safe state reachable set based on the trajectory beam of multiple security target locations. On this basis, the condition of the inevitable collision of vehicle was analyzed, and the optimal control problem with loose constraints for the vehicle obstacle avoidance was proposed. The simulation results show that the method can not only plan trajectories for vehicle avoiding obstacle, but also infer the reachable range of security state of vehicle,and the predictive power of vehicle state security is enhanced within a future time interval.

Key words: safety path, road traffic, hybrid systems, reachable set, trajectory planning