A Regenerative Braking Strategy for Independently Driven Electric Wheel Accounting for Contemporary Use of Electric and Hydraulic Brakes

The growth of electric mobility showed the possibility of reinventing the vehicle powertrain layout. The adoption of one motor per wheel allows to precisely control the driving and braking torque on each wheel. However, conventional friction brakes are necessary to guarantee top braking performance of the car since, in general, the braking toque by electric motor is not enough to perform maximum deceleration manoeuvres. A suitable blended braking distribution strategy must be designed to distribute the torques on the wheel by accounting for the vehicle state, the driver request, and the torque vectoring request by stability control algorithm. This paper presents and optimal control strategy that distributed the braking torques on the wheel accounting for electric and hydraulic brakes. The control algorithm considers than the regulations requirements, the wheel vertical load condition both in longitudinal and lateral dynamics conditions, and the request by driver and stability control.