Research On Steering Stability Control Of Distributed Drive Vehicle Based On Optimal Drive/Brake Mode

Vehicle stability control has always been the focus of research in the field of vehicle active safety.Distributed drive electric vehicles are different from traditional vehicles due to their structure,and the improvement of its stability control scheme is one of the current research hotspots.Aiming at the problems that the current stability control scheme of distributed driving vehicles is not perfect in the stability region division in the instability determination method,and it fails to make full use of the flexible and variable advantages of its driving/braking mode,this paper uses four-wheel hub Motor distributed driving vehicles are the research object,aiming at optimizing the instability determination method and improving the ultimate stability of the vehicle,the instability determination process based on the stability index is proposed,and the optimal driving/braking stability control scheme is designed.Research on vehicle steering stability control:Firstly,the influencing factors and characterization parameters of vehicle stability are analyzed,and reasonable control variables are selected.Based on the yaw rate error band method and the five-parameter rhombic phase plane of the side slip angle-side slip angle velocity,a method for judging vehicle instability is proposed.By exploring the influence of different driving/braking modes on the boundary of the vehicle stability region,the optimal mode under extreme conditions is obtained.Secondly,a hierarchical optimal drive/brake mode steering stability control scheme is designed.The vehicle speed following and slip rate control modules during the steering process are established,and the β-ω combined sliding mode controller is designed based on the direct yaw moment method,and the stability index is used for the control ratio distribution,and finally the additional yaw moment is decided.In the lower layer,factors such as road adhesion utilization rate,load transfer and optimal driving/braking mode are considered for optimal torque distribution.Then based on the Carsim-Matlab/Simulink simulation software,a co-simulation platform for the steering stability control scheme is constructed,including the vehicle simulation model,the driver’s road model and the control model.Finally,the simulation results of dynamic load and optimal drive/brake control scheme are compared under open-loop and closed-loop conditions.And put forward the control effect evaluation system with control efficiency as the index.A comparative analysis of the dynamic load and the ability of the optimal drive/brake control scheme to control error peaks is carried out.The results show that the optimal drive/brake control has a better control effect and can more effectively improve the steering stability of the vehicle.The research results of this paper are conducive to giving full play to the structural advantages of distributed drive electric vehicles,improving the ultimate stability of the vehicle,optimizing the design of driver assistance systems,and expanding the application of theoretical research in engineering practice.