Research On Platoon Control Of Commercial Vehicles Based On Safety Spacing Policy

The commercial Vehicle platoon uses on-board sensors,Vehicle-to-vehicle communication,automatic control and other technologies to keep a reasonable workshop distance between vehicles in the platoon,so as to reduce fuel consumption and pollutant emission.Commercial vehicles running in platoon can save energy and reduce emission by shortening vehicle distance,but it also increases the safety risk of rear-end collision.To ensure the stability of the platoon is the prerequisite for preventing rear-end collision and safe driving.Therefore,it is necessary to design reasonable spacing policy and platoon controller to ensure the stability of the platoon.In addition,the target speed and target trajectory of the leading vehicle in the platoon will have an impact on the tracking of the following vehicle,and the lateral and longitudinal driving control of the commercial vehicle platoon is also a problem that needs to be studied in platoon control.Therefore,from the perspective of ensuring the safe and stable running of the platoon,it is of great significance to study the safe spacing policy of commercial vehicle platoon and the lateral and longitudinal controller.To solve the above problems,this paper is financially supported by Jilin Province Science and Technology Development Plan Projects "Research on decision-making and control of automatic lane change of electric vehicle with X-by-Wire chassis"(No.:20230101121JC).Based on the research status of vehicle platoons,this paper designs the safety spacing strategy and the lateral and longitudinal controllers suitable for commercial vehicle platoons.Firstly,a safe spacing policy is designed to keep a reasonable spacing between vehicles in the platoon.Secondly,the longitudinal coupling integral sliding mode controller of the commercial vehicle platoon is intended to ensure the safe and stable driving of the platoon.Then,the target speed and target trajectory of the leading vehicle in the platoon are planned respectively.Finally,the platoon lateral trajectory tracking controller is designed,and the effectiveness of the platoon longitudinal coupling integral sliding mode controller and platoon lateral trajectory tracking controller is verified.The main research work is as follows:(1)Analysis of conventional spacing policy and design of safe spacing strategy.Firstly,the existing traditional spacing strategies are analyzed and compared,and their respective advantages are summarized.Then,based on the traditional spacing policy,according to the influence of road environment and vehicle state on the distance between platoons,a platoon safety spacing policy was proposed which also considered the driving speed,road adhesion coefficient,and braking delay factors.Finally,the designed safety spacing policy is compared with the constant spacing policy,constant time headway spacing policy and variable time headway spacing policy.(2)Design and stability analysis of longitudinal coupled-integral sliding mode controller for commercial vehicle platoon.Firstly,the integrated sliding mode controller is improved by coupling the integrated sliding mode surface,and the longitudinal coupled-integral sliding mode controller is designed based on the proposed platoon safe spacing policy.Then,through Lyapunov stability analysis,it is proved that the coupled-integral sliding mode controller can ensure the stable driving of the platoon.Finally,the designed coupled-integral sliding mode controller is compared with the controller based on adaptive cruise strategy and series PID control strategy to verify the effectiveness of the designed coupled-integral sliding mode controller.(3)Target speed and target trajectory planning of leading vehicle.Firstly,the quadratic programming algorithm is used to design the target speed of the leading vehicle,so that the target speed of the leading vehicle in the platoon satisfies the vehicle dynamics constraints.Then,based on the quintic polynomial trajectory planning algorithm,the target lane-changing trajectory of the leading vehicle is planned.Finally,test and verify the trajectory tracking control strategy of the leading vehicle changing lanes.(4)Design of lateral trajectory tracking controller for commercial vehicle platoon and simulation verification of lateral and longitudinal controllers.Firstly,the LQR algorithm and feed-forward control are used to design the lateral trajectory tracking controller of the platoon,so that the vehicles in the platoon can complete the function of changing lanes.Then,build a co-simulation test platform based on Truck Sim and MATLAB/Simulink,establish a commercial vehicle platoon driving simulation environment,set up the typical working conditions of acceleration and deceleration cruise and emergency braking,and conduct a coupled-integral sliding mode controller,based on adaptive cruise strategy controller and A series of PID controllers is used for simulation comparison verification.Finally,the straight-line driving and lanechanging driving conditions are set,and the simulation test and verification of the lateral trajectory tracking controller and the longitudinal coupling integral sliding mode controller are carried out.