ADVANCED VEHICLE MOTION CONTROL OF ELECTRIC VEHICLE BASED ON THE FAST MOTOR TORQUE RESPONSE

One remarkable merit of Electric Vehicles (EVs) is the electric motor’s excellent performance in motion control. This merit can be summarized as: (1) torque generation is very quick and accurate, (2) output torque is easily comprehensible, (3) and motor can be small enough to be attached to each wheel. To utilize these advantages of EVs, we have carried out some studies on motion control of EVs. First of this paper, the feedback control of wheel velocity is discussed. The controller increases the wheel inertia equivalently and prevents the sudden rise of slip ratio. Experiments with actual EV and slippery road confirmed this effect. We assume that this method should be some minor loop controller. From such viewpoint, we discuss on two applications. One is concerning with lateral motion stability. Our simulation results show that unstable lateral motion on slippery curve can be stabilized with “4 wheel-motored” EV, if the wheel velocity controller is applied to each wheel as “autonomous” stabilizer. The other application is cooperative control of regenerative control and hydraulic ABS. Regenerative braking torque is controlled to have “large” inertia against hydraulic braking torque. This minor loop controller enhances the short-time dynamics of ABS and decreases the braking distance.