Research On Stability Control Of Four-Wheel Independent Drive Electric Vehicle Under The Typical Operating Conditions

The recent twenty years has witnessed the rapid development and wide use of electric vehicles which own the characteristics of environmental protection and energy saving.Based on its flexible control and quick response,4WID(Four Wheel Independent Drive)electric vehicles,which possess an ideal drive mode,have become a hot spot of research.How to distribute the torque of four tires reasonably plays an important role in the research of control of stability.Only by this,can we use adhesive force of 4WID electric vehicles legitimately,drive steadily and optimize it.The object of this essay is 4WID electric vehicles.Main researches are as follows:1.System features and the key technology of 4WID electric vehicles are analyzed,while integrated control algorithm is studied.The control structure of this essay is established according to hierarchical control.This kind of structure is consisted of upper integrated control layer and the lower distribution layer.2.Based on the joint simulation platform Carsim-Simulink,full vehicle model,Dugoff tire model,direct current dynamo model and ideal reference model are established.Therefore,the control algorithm of upper integrated control layer is built on the basis of model control theory.3.The control algorithm of lower distribution layer is designed according to the minimum adhesive rate of tires.Constraint optimization problems are analyzed and solved in this essay.In the meantime,the inverse model of Dugoff tires are set up on account of inverse derivation.4.In order to verify the control effects of integrated control algorithm of 4WID electric vehicles,emulation proof of typical driving condition is processed on the basis of the joint simulation platform Carsim-Simulink.Results show that this integrated algorithm can control the utilization rate of tires,decrease the maximum rate and promote their adhesive ability.Compared with vehicles controlled by ESP,these ones have less possibilities of spin side slip and higher stability.