A novel traction control of EV based on maximum effective torque estimation

Controlling an immeasurable state with an indirect control input is a difficult problem faced in traction control of a vehicle. Research on motion control of electric vehicles has progressed considerably, but anti-slip control has not been so sophisticated and practical because of this difficulty. Therefore, this work takes advantage of the features of motors to estimate the maximum friction force from road in real time based on a pure kinematic relationship between the wheel and the chassis. Then, a half-closed loop controller makes use of the estimated value to limit the maximum torque output to the wheel. The resulting control design approach is shown to be effective and practical on an experimental electric vehicle as well as through simulations.