Research On Stability Control Strategy Of Vehicle Body Of Four Wheel Drive Electric Vehicle

With the problem of environmental pollution and energy conservation issuesbecoming increasingly prominent, it has become a trend that electric vehicle willgradually replace the traditional car, and with the improvement of the vehicle activesecurity requirements, how to improve the stability of the body of electric vehicle is oneof the main research directions. This thesis focuses on the design of four-wheel-driveelectric vehicle adaptive control system, in order to improve the ability of vehiclestability. The main work is as follows：1. Researched the mathematical model of four-wheel drive electric vehicle, andbased on the DYNAware car model, the simulation model of four-wheel-drive electricvehicle is modeled. In the same and typical condition, the simulation model offour-wheel-drive electric vehicle and the traditional car model of DYNAware weresimulated and compared.2. Using the linear two degree of car model as the ideal reference model of4WDEV, the thesis researches the stability of reference model, analyses yaw rate andslip angle to the significance of vehicle stability. The method of designing controller isresearched, that is based on the theory of model reference adaptive control, the thesishas designed an adaptive controller of four-wheel-drive electric vehicle, which is basedon the ideal reference model. Due to the restrictions of the adhesion ability of road andthe unpredictability of road surface friction coefficient, the thesis design a dynamicadjusting strategy of yaw rate, which is based on slip angle and the simulation resultsshow that the effectiveness of the adaptive controller and a dynamic adjustmentachieves the desired goals.3. Based on the above work，the thesis uses the four-wheel-drive electric vehicleadaptive controller in control system, combined with dynamic adjusting strategy of yawrate. The control system is simulated in MATLAB and DYNAware, and the results showthat the response output of four-wheel-drive electric vehicle can track the output of thereference model, meet the driver’s expectations, limit the increasing of slip angle at the same time and enhance the maneuverability and the ability of vehicle stability offour-wheel-drive electric vehicle.