Study On Traction Control Strategy Of Four-wheel Independently Driven Vehicle Based On Threshold Algorithm

Electric vehicle which is driven by hub motors is in possession of someadvantages such as light-weight, almost zero-emission, easily controlled by modernintelligent instrument, high efficiency in energy-consumption and low-noise, Right now,in the democratic and overseas researching field, the research which is about chassistechnology of driven-by-hub-motor electric vehicle is mainly focusing on design of hubmotor and suspension system. At the same time, some researchers put their hands in ABS,TCS, vehicle ride comfort and match between character of motor and vehicle. This paperis based on the item about electric vehicle key technology research which is sponsored bythe first automotive works research and design center and the rich experienceaccumulated by the innovation research team of EV&HEV Key Technology, JilinUniversity. Considering the character of hub-motor, this paper carried out deep researchon TCS of driven-by-hub-motor electric vehicle.Firstly, this paper analyzed the democratic and overseas development status of theapplication of driven-by-hub-motor electric vehicle and its chassis technology anddescribed the TCS in detail.Secondly, focusing on the concrete vehicle model, given that the advantages ofAMESim software, this paper built the whole vehicle model which consists of15freedom chassis model, driver model, motor model. Sensor model and tire model and theinterface of AMESim and Matlab/Simulink etc.Thirdly, this paper distributed the required torque according the front and rear axlelive load, then for some concrete situations changed the front or rear axle torque to theother axle in order to maintain the vehicle dynamic performance., When the tire slip ratiocomes to certain level, the utilized adhesion coefficient can be regarded the roadadhesion coefficient which is crucial for the TCS to chose proper control parameters fordifferent adhesion roads Fourthly, this paper chose the logic threshold algorism which is based on slip ratioand analyzed the principle of logic threshold, then constructed the control structure andcontrol target and built the wheel speed and wheel acceleration speed model, vehiclespeed estimation model, target speed model, control strategy model and TCS start andend model.At last, this paper chose typical, situations to testify the validity and utilization ofpresented control strategy, the results showed that the strategy can work well.