Wheel-speed based Driving Force Control for On-board Motor Electric Vehicles with Absolute Stability Analysis and HIL Evaluation

Driving force control (DFC) has been well-developed for in-wheel-motor electric vehicles (IWM-EVs). However, due to the powertrain complexity, DFC for on-board motor electric vehicles (OBM-EVs) is still an open challenge, especially in system configuration and stability analysis. To address these issues, this paper proposes (i) a novel cascade two-degree-of-freedom DFC for OBM-EVs and (ii) an absolute stability analysis of the overall system with respect to the maximum allowable wheel speed, which depends on the driving situation. In the outer layer, a feedback-feedforward reaction force controller directly generates the wheel speed references. In the inner layer, a feedback-feedforward speed controller generates the motor torque. By utilizing a real IWM-EV, a hardware-in-the-loop (HIL) system is developed to imitate the OBM-EV properly. HIL results show that the proposed stability analysis can effectively predict the system behavior. The proposed system successfully improves the DFC performances with quick response, less vibration, and accurate tracking.