A Vehicle Torque Distribution Method Combining Nonlinear Control and Optimization Techniques

Good stability is a prerequisite for vehicle operation. However, under certain extreme conditions, the vehicle’s state can quickly change and stability can be lost. In order to improve the stability of distributed drive electric vehicles (DDEVs) under these conditions, this paper proposes a hierarchical control strategy. The upper-level controller adopts a backstepping nonlinear control method to achieve stable yaw rate control. The lower-level controller combines backstepping and optimization to take into account the desired tire slip ratio while minimizing driver intervention and considering limited motor torque. Experimental results show that the proposed control strategy is superior to the average distribution (AD) strategy. The proposed control strategy can meet various requirements such as longitudinal/lateral stability, while reducing the interference on the driver’s torque demand in hazardous situations.