Stability Control of 4 Wheel Motored Electric Vehicle utilizing Electric Motor's Advanced Controllability

点击翻译按钮获取中文摘要

Electric vehicles (EV) have much advantage which is not in gasoline engine vehicles, One is the traction control utilizing electric motor's quick torque response and another is the high performance vehicle attitude control by multi motored-wheel vehicles.On the first subject we developed novel adhesion control methods and good experimental results were obtained by using UOT March I, which is our first test vehicle. This time, we developed the second vehicle UOT March II, 4 motored wheel vehicle. and the following results have been obtained mainly on the two-dimensional vehicle attitude control.(1) adhesion controlWe investigated electric rail cars and ABS systems of gas engine vehicle, where adhesion control are being applied. We also studied generation mechanism of tire friction force and rolling resistance. We optimized some controller parameters of already proposed MFC, the optimal slip ratio control, etc.(2) road condition estimationWe proposed the driving force observer which is n … More eeded for adhesion control as the road condition estimator. We applied the fixed trace method to estimate the slope of the road friction curve form time derivatives of the slip ratio and the road friction coefficient. Also, we developed the maximum friction coefficient estimation technique using precise tire model and nonlinear search algorithm, skid detection method without using vehicle speed, and so on.(3) two-dimensional vehicle attitude controlWe developed various types of vehicle attitude stabilization techniques using nonlinear state equations expressing vehicle dynamics. For example, anti-windup yaw rate control considering traction force saturation, maximum braking force control at emergency and its application to anti-spin control with drivers' steering action, dynamic driving force dispatch control, and so on. 4 motored EV can generate the yaw moment force directly as the controlled input variable, which realizes a completely different system from the conventional 4WD or 4WS vehicles.(4) manufacturing of the real vehicle and experimentsWe took much effort in making the hand-made UOT March II.It was completed and we are still performing experiments on a tire maker's test course. We expect much more experimental results in the near future.When we will succeed in the above technology development, danger of tire slip will be reduced drastically, safety of drive on slippery road will be increased by high performance attitude control, and if we use lower loss tire we can increase the range of one battery charge. In summary, we can say that we have succeeded in basic experiments to show great advantage of electric vehicles in "control". Less