Model Predictive Control of an All-Wheel Drive Vehicle Considering Input and State Constraints

Abstract

This paper suggests a novel model-based control scheme for an all-wheel drive (AWD) vehicle. Using transfer case, AWD system is able to transfer the engine torque to all the wheels mechanically, helping the vehicle to maintain traction on a slippery road or to climb a hill. Recently, an active type AWD system that is able to control the torque transmitted through transfer case continuously by the aid of electronic clutch actuator has become popular. In order to realize preemptive operation which is necessary property for AWD system while simultaneously considering states and input constraints which is originated from mechanical and physical characteristics, this paper adopted model predictive control (MPC) concept. The proposed MPC-based controller was designed by using planar full-car model that is based on tire force and motion states, which represents the direct relationship between these states and control input. Therefore, the planar full-car model contributed the suggested controller to follow standard MPC design process. The target states of longitudinal wheel slip and yaw rate, which have commonly been adopted in previous studies, were selected for practical concerns. The advantages of the suggested MPC-based controller that is designed especially for an AWD system were validated by conducting simulations through a SimulinkCarSim-based AWD vehicle model.