Basic Study on Wheel Speed Based Driving Force Control for Multi-motor Electric Vehicles with Glocal Stability Analysis

This paper presents a novel driving force control (DFC) strategy for electric vehicles driven by multi-motors. The proposed system is designed hierarchically, with driving force control in the outer-layer, and wheel speed control in the inner-layer. Notably, the outer-layer controller directly outputs the wheel speed references. This configuration does not requires the vehicle speed to calculate the wheel speed as the traditional DFC, thereby reducing system complexity. Moreover, this paper shows that the proposed system can be modelled as a multi-agent system with generalized frequency variable and a physical interaction matrix of rank-1. This allows us to guarantee the stability of the total system (global) with respect to the actuator dynamics (local). In particular, this paper establishes a D-stability condition, which is independent of the number of motor actuators. The proposed strategy is applied to range extension control via energy optimization by driving force distribution and control.