Research On Collision Avoidance Control Strategy At Manned/Unmanned Vehicles Mixed Traffic Intersections

With the development of driver assistance and automatic driving technology,the mixed driving scene of manned vehicles and unmanned vehicles has gradually become normal.It is of far-reaching realistic significance to study how to control unmanned vehicles to avoid collisions in the mixed driving environment,especially in the intersection without signal light control.Traditional vehicle longitudinal assistant system in such a situation exists in the low efficiency of traffic,to solve this problem,based on the unmanned vehicle as the research object,this paper designs a kind of vehicle control strategy.In urban road environment,the control strategy can maximally avoid vehicle collision,ensures the safety of the pedestrian.At the same time,compared with the traditional longitudinal assistance system,it can effectively improve the efficiency of unmanned vehicles passing the intersection.Firstly,the math model of the vehicle is established,including longitudinal braking process analysis and lateral dynamics model.Then,a longitudinal control strategy based on time sequence is designed by using longitudinal kinematics model,which includes three levels of braking strategy.This strategy not only ensures that vehicles do not crash,but also improves the efficiency of vehicles passing through the intersection,and also takes into account the comfort of occupants when braking.For the condition that the longitudinal control strategy cannot control the vehicle to avoid collision,as a supplement,a steering control strategy is designed in this paper,which includes two parts: decision module and controller.In the decision module,the relative position of the two vehicles when the collision is about to happen is analyzed to determine the calculation formula of the lateral displacement required by the unmanned vehicle when the collision can be avoided.Meanwhile,the steering strategy is selected according to the principle of minimum displacement.According to the output of the steering decision module,the steering controller is designed by using the model predictive control method to track the desired trajectory.Based on the Carsim vehicle simulation software provides rich road environment,building manned/unmanned vehicle mixed traffic intersection.At the same time,using the high precision of the vehicle model provided by Carsim software,the unmanned vehicle control strategy designed by this paper is validated,the simulation results show that the control strategy can avoid collision between vehicles as far as possible,and effectively improve the efficiency of vehicles through the intersection.Research of this paper effectively solves the control problem of unmanned vehicle at the manned/unmanned vehicle mixed traffic intersection without traffic light,through lateral and longitudinal control.The unmanned vehicles can avoid collisions as far as possible,while trying not to stop through the intersection,which is helpful to guarantee the traffic safety and improve traffic efficiency at the controlled intersection without traffic lights...