Comprehensive Optimization of Dynamics Performance and Energy Consumption for an Electric Vehicle via Coordinated Control of SBW and FIWMA

This paper presents a coordinated controller for comprehensive optimization of vehicle dynamics performance and energy consumption for a full drive-by-wire electric vehicle, which is driven by a four in-wheel motor actuated (FIWMA) system and steered by a steer-by-wire (SBW) system. In order to coordinate the FIWMA and SBW systems, the mechanisms influencing the vehicle dynamics control performance and the energy consumption of the two systems are first derived. Second, the controllers for each subsystem are developed. For the SBW system, a triple-step control technique is implemented to decouple the yaw rate and sideslip angle controls. The FIWMA system controller is designed with a hierarchical control scheme, which is able not only to satisfy the yaw rate and sideslip angle tracking demands, but also to deal with actuation redundancy and constraints. Finally, coordinated control is proposed to obtain the comprehensive optimization of the vehicle dynamics control performance and energy consumption. The developed coordinated control is convenient for implementation as the structures and control algorithms of the subsystems remain unchanged. In this way, the control algorithms of the subsystems can be developed independently. Simulations are carried out with a CarSim software full-vehicle model under two typical driving scenarios, and with different road conditions. The results show the effectiveness of the developed coordinated control.