Research On The Multi-Vehicle Cooperative Automated Lane Change Maneuver Based On Vehicle-to-vehicle Communication

Automated driving is a hot area in industrial circle and academia.It is important to make researches on the automated lane change,one of the main automated driving technology.The present researches on automated lane change only concentrated on the one vehicle lane change in the scenario.However,it is still a new area for more complicated scenarios.Simultaneously,with vehicle-to-vehicle communication developing,it is possible to do researches on multi-vehicles cooperative lane change.Therefore,for the scenario of eighty vehicles on three lanes,multi-vehicles cooperative automated lane change maneuver based on vehicle-to-vehicle communication is proposed.With the object of the scenario of eighty vehicles on three lanes,the same-direction cooperation and intersectant-direction cooperation lane change are proposed according to the two vehicles' lane change directions.In the two cooperation scenarios,the vehicle to make cooperative decision gains the information of surrounding vehicles,on base of which all of trajectories are cooperatively made to be distributed to all surrounding vehicles.And all vehicles track their own reference trajectory.For this point,multi-vehicles cooperative automated lane change maneuver is proposed,which is comprised of cooperative trajectory planning and trajectory tracking.Cooperative trajectory planning is composed of muti-vehicles safety spacing model and trajectory making.In the process of lane change,to guarantee the safety of all vehicles,cooperation lane change safety spacing model is proposed and the minimum safety model between the vehicles to keep straight and the lane change vehicles,which build a constraint of trajectory planning.To make trajectories,quantic polynomial is employed as the parametric equations.And the problem of solving parameters is converted to optimization problems with two parameters(lane-change time and longitudinal displacement)with the goal of safety,comfort and lane change efficiency,and on the constraints of vehicle dynamics and safety spacing models,which can be solved through interior point method.To simplify the control of the vehicles to keep straight,their movements are planned to drive with uniform motion.In order to implement the tracking,trajectory tracking based on model predictive control method is designed.Vehicle kinematics model with three DOF that is firstly linearize and discretized is converted to error predictive model.With the object of tracking errors and control increment,it is converted to quadratic optimization.Finally,the desired velocity and front wheel steering angle are optimized,which is converted to the controller inputs with driving torque and steering wheel angle.In order to verify the validity of the proposed multi-vehicles cooperative automated lane change maneuver,the united simulation platform combining MATLAB/Simulink with CarSim is build.Several representative working conditions are simulated and analyzed systematically.On the other hand,a hardware-in-the-loop(HIL)test bench is developed for four representative working conditions.The results of both simulation and test show that the proposed multi-vehicles cooperative automated lane change maneuver based on vehicle-to-vehicle communication can achieve simultaneous lane-change of two vehicles,and increase lane-change efficiency under the guarantee of the lane-change safety and comfort and in the scenario.