Electrified Vehicle Wheel Slip Control Using Responsiveness of Regenerative Braking

Abstract

In vehicles, wheel locking and associated instability issues can be prevented by regulating wheel brake torque during braking. In contrast with conventional vehicles, electrified vehicles have both friction and regenerative braking. Typically, pneumatic friction braking is used for Wheel Slip Regulation (WSR) in Heavy Commercial Road Vehicles (HCRVs). However, the pneumatic brake system has a lower bandwidth compared to a regenerative brake system, thereby affecting the braking performance of the HCRV during WSR application. This article proposes an Integral Sliding Mode Control (ISMC) based WSR to exploit the responsiveness of regenerative brakes during braking. The proposed control strategy was evaluated in a hardware-in-loop experimental setup. For different operating conditions, the experimental results conveyed that the proposed braking strategy incorporating regenerative braking reduced the slip ratio tracking root mean square error and stopping distance in the range of 12.13% to 72% and 2.43% to 4% respectively compared to conventional frictional braking (without regenerative braking).