Energy Management And Coordinated Slip Ratio Control For Hybrid All-terrain Vehicle

All-Terrain Vehicle(ATV)has been widely used in sports,outdoor work and other fields due to its advantages of small size and good maneuverability.With the development of the economy and society,people’s living standards have improved,the vehicles that can drive freely in extreme road conditions such as deserts,jungles and swamps are increasingly demanded,with the sign that allterrain vehicles have ushered in another golden period.However,in recent years,stringent environmental regulations have challenged ATVs that are mainly pursuing power performance.How to improve the fuel economy of the vehicle while ensuring its power has become a difficult and critical issue for ATV research.Aiming at the problem that the ATV is prone to wheel slip when accelerating or braking on low adhesion roads,this paper conducts a research on the slip ratio coordinated control based on the planetary hybrid ATV system.The main research contents include:First,in accordance with the research objectives of this article,develop a planetary hybrid all-terrain vehicle system configuration scheme,build a mathematical model of the planetary gear power coupling device based on the dynamic analysis results inside the planetary gear mechanism in the Matlab/Simulink software environment.Build a simulation model of the entire vehicle and key power components.Aiming at the configuration characteristics of the hybrid ATV system,the speed and torque decoupling between the engine and the wheel can be realized.By analyzing the energy flow mode,a steady-state energy management strategy based on the optimal working curve of the engine is developed.Test cycle conditions were simulated and verified.Moreover,the establishment of a model capable of describing the dynamic characteristics of tires is a prerequisite for the coordinated control of ATV slip ratio.Aiming at the research objectives of this research topic,the LuGre tire model was selected as the research object.Through the study of LuGre friction theory,a dynamic tire model oriented to slip rate control was established.The distributed LuGre tire model was analyzed for steady-state characteristics to coordinate the slip rate.The calculation of the target slip ratio in the control provides a theoretical basis;the tire model parameters are identified based on the least squares method,and the effects of tire longitudinal stiffness,Coulomb friction coefficient,static friction coefficient,and road adhesion conditions on the friction characteristics are analyzed based on the identified results.Furthermore,to solve the problem of the slip ratio coordination control of hybrid all-terrain vehicle,based on the system’s multiple power source characteristics and the control objectives of this study,a slip rate coordination controller based on adaptive Backstepping control theory was designed;The control targets of the controller were simulated on the low adhesion coefficient uniform road,high adhesion coefficient uniform road,and joint road.The designed slip ratio coordination controllers were simulated and tested.The results show that the braking and driving capabilities have been improved to a certain extent,and the control strategy can basically make ATVs adapt to changes in the road surface,and the control effect is better.