Coordinated Control Of Stability And Path Tracking Of Four-Wheel Independent Drive Trolley Car

At present,in the development of automobile industry,the electric and intelligent automobile has become the development trend.Electric cars can reduce consumption of non-renewable resources and enhance environmental protection,and their NVH(Noise,Vibration,Harshness)quality can leave traditional fuel cars in the dust.Among them,four-wheel independent drive,as a kind of driving mode with motor mounted on the wheel,can independently and accurately control the driving torque and speed of each wheel,which is more suitable for accurate control algorithm.Unmanned driving technology is the key technology to reduce the incidence of traffic accidents.In order to achieve safe unmanned driving of vehicles,it is necessary to coordinate the control of vehicle trajectory tracking and stability.Therefore,this paper will take the four-wheel independent drive electric vehicle as the object to design a trajectory tracking and stability coordination control strategy for the unmanned vehicle under high-speed conditions.First of all,the Carsim vehicle model is established,and the hub motor Simulink model is established,and the Carsim interface is set according to the control requirements in the following text.After that,a joint verification platform was established to verify the dynamic performance,steering performance and dynamic response of the wheel motor Simulink model of the vehicle model under two conditions of straight driving and step steering.A cooperative control strategy of lateral stability and trajectory tracking was proposed to solve the problem of vehicle stability,dynamic performance and tracking accuracy during vehicle trajectory tracking.Firstly,a multi-objective sliding mode controller for path tracking and lateral stability is established,and the weight coefficients of trajectory tracking and lateral stability are determined by the extension domain idea,and the coordinated control of trajectory tracking and lateral stability is realized by adjusting the weight coefficients online.Because the car is a highly nonlinear system,ignore the lateral movement of the mutual influence will naturally reduce the control effect and reduce the driving safety,and considering the distributed driving ev driving mode is different with the traditional cars,need to establish a suitable for distributed drive torque distribution strategy of electric cars,so in the lower level controller,A tire torque distribution strategy for distributed drive electric vehicle was proposed,which considered both lateral stability and longitudinal velocity stability,and finally realized the coordinated control of vehicle stability and trajectory tracking.In order to verify the effectiveness of the controller,Simulink-CarSim co-simulation is carried out,and the results show that the proposed control strategy makes the vehicle track accurately and ensures the stability of the vehicle when driving.