Driving Force Control for On-board Motor Electric Vehicles with Adaptive Drivetrain Friction and Phase Stabilization Speed Controller

Driving force control (DFC) has been shown as a successful method for improving the safety and comfort of in-wheel-motor electric vehicles (IWM-EVs). However, DFC for on-board motor (OBM) EVs faces many challenges due to the complexity and parameter uncertainty of the powertrain system, which includes gear, differential, and drive shaft. Aiming to solve the aforementioned issues, this paper presents a new DFC system for OBM-EVs with the force controller in the outer loop, and the motor speed controller in the inner loop. To achieve phase stabilization, the proportional-integral-derivative (PID) controller with a phase lead compensator is proposed for the inner loop. By integrating disturbance observer and least square algorithm, a novel adaptive driving force observer (A-DFO) is proposed to simultaneously estimate the driving force and the viscous friction coefficient of the drivetrain. A hardware-in-the-loop (HIL) experiment is introduced to show that it is possible to design DFC for OBM-EVs using IEMEVs. Numerical simulations and Hardware-in-loop experiments show that the proposed system can accurately estimate and control the driving force. Especially, the tracking errors and vibrations are remarkably reduced in comparison with some existing control approaches.