Research On Lane Keeping Control For Commercial Vehicle Based On Improved Artificial Potential Field Algorithm

With the rapid development of logistics industry in China,commercial vehicles undertake the heavy logistics and freight tasks as the main strength of road transportation.Meanwhile traffic accident caused by driving fatigue is frequent.Lane keeping system(LKS)can keep the vehicle along the target lane according to the road environment and vehicle states,which can play an important role in reducing traffic accident.Due to the characteristics of large load and high center of mass,commercial vehicles are prone to be instable.Therefore,the driving stability of commercial vehicles is an important index,which cannot be ignored in the process of lane keeping control.Based on the background,the lane keeping control strategy for commercial vehicles considering driving stability is proposed and it focus on the prevention of instability that is reflected in the upper control level of lane keeping rather than the executive level.The vehicle dynamics characteristics are fully taken into account and the controller parameters are optimized,which could improve the efficiency and safety of vehicle control.The main work is as followed:(1)According to the parameters of prototype vehicle,the vehicle model and road model are built in TruckSim.The vehicle dynamic model is established as the reference of the controller,and compared with the vehicle model in TruckSim.The parameters of electronically controlled hybrid power steering(ECHBPS)are matched,and the dynamic model of ECHBPS is built under the condition of unmanned driving.According to the kinematic geometry,the TLC calculation under straight and curve condition are deduced.(2)The steering stability of commercial vehicle is analyzed,including the influence of the front wheel angle on the dynamic parameters and the formation mechanism of sideslip and rollover.TLC,yaw rate and lateral acceleration repulsion potential fields are constructed on the basis of the traditional road artificial potential field(APF),and a lane keeping controller for commercial vehicles is designed based on the improved APF.The Lyapunov stability of the new control system is proved,and the range of gains of potential field function is obtained.(3)In order to keep a balance between the path tracking accuracy and driving stability,a comprehensive evaluation index of lane keeping control for commercial vehicles is established.The steering angle tracking controller based on integral separation PID control for ECHBPS is designed,and the tracking control effect is verified under the input conditions of step,hook and sinusoidal angle.Taking the comprehensive evaluation index as the fitness function,the adaptive inertia weighted particle swarm optimization(AIWPSO)algorithm is used to optimize the parameters of the controller to obtain the optimal gain of each potential field function.(4)The optimization result is put into the controller and the co-simulation analysis is carried out.The analysis result shows that the improved APF control reduces the overshoot of lateral deviation by 65.99% and 22.78% respectively,compared with the road APF and the single-point preview driver model under the straight road condition at the speed of 70km/h.It can be seen that the control response is faster and the deviation correction ability is stronger.Under the double lane change condition,the improved APF control precision is higher and it has peak-clipping effect on yaw rate and roll angle in big corner obviously,which makes yaw rate and roll angle lower than the instability limit.In terms of the comprehensive evaluation index,the value is reduced by23.4% and 6.5% respectively.(5)The hardware-in-loop test of lane keeping control strategy based on the improved APF algorithm designed in this paper is carried out on the VCU HiL platform.The test result shows that the proposed control strategy can function effectively in the real controller,which meets the requirement of lane keeping control,and has a good effect in prevention of instability control.In conclusion,the lane keep control strategy for commercial vehicles considering driving stability is put forward in this paper,which provides the beneficial reference for lateral vehicle dynamics control research of commercial vehicle,and has positive social benefits in terms of reducing traffic accidents.In addition,this study also enriches the theory development and practical application of artificial potential field method in the field of intelligent driving.