A hierarchical energy efficiency optimization control strategy for distributed drive electric vehicles

Abstract

Distributed drive electric vehicle with four in-wheel motors is widespread with various characteristics, such as performance potentials for independent wheel drive control and energy efficiency. However, in future, one of the biggest obstacles for its success in the automotive industry would be its limited energy storage. This paper proposes a hierarchical control method that involves a high-level motion controller that uses sliding mode control to calculate the total desired force and yaw moment and a low-level allocation controller in which an optimal energy-efficient control allocation scheme is presented to provide optimally distributed torques of four in-wheel motors in all the normal cases. A practicable motor energy efficiency model as a motor actuator is proposed by incorporating the electric motor efficiency map based on measured data into the motor efficiency experiment and a current closed-loop motor model. Moreover, both tracking performance and energy-saving are carried out in this research and evaluated via a co-simulation approach using MATLAB/Simulink and CarSim. A ramp maneuver at a constant speed and New European Driving Cycle and Urban Dynamometer Driving Schedule maneuvers have been conducted. To conclude, it is demonstrated that distributed drive electric vehicle with four in-wheel motors can reduce total power consumption and enhance tracking performance compared with a simple control allocation in which the torques are the fixed ratio distribution.

An adaptive-prediction-horizon model prediction control for path tracking in a four-wheel independent control electric vehicle

“…For the above, based on the four-wheel independent control electric vehicle (FWIC-EV) (provided with independent driving/braking/steering and realizing autonomous driving with more dynamic flexibility [23][24][25][26] ), this paper proposes a path tracking controller basing adaptive-prediction-horizon MPC (APH-MPC), in which the potentiality of the MPC path tracking controller is deeply exploited by adjusting online the prediction horizon to variable requirements of dynamic stability and tracking accuracy. Meanwhile, the dynamic stability is quantized with the vehicle sideslip-feature phase plane.…”

Coordinated control of stability and economy based on torque distribution of distributed drive electric vehicle

“…Considering the safety and economy of the DDEV, the coordinated torque distribution control is considered from both safety and economic aspects. 18–20…”

“…The results show that the proposed method can both improve tracking performance and reduce the total power consumption. 20…”

“…Considering the safety and economy of the DDEV, the coordinated torque distribution control is considered from both safety and economic aspects. [18][19][20] Li et al 18 comprehensively consider the steer-bywire system and the four-wheel drive system, and propose a coordinated control algorithm based on vehicle dynamics and energy optimization of the drive system. Chen and Wang 19 proposed a hierarchical control structure based on dynamic sliding mode control (SMC) and adaptive energy-efficient control allocation (A-EECA) scheme, which is used to track the driving trajectory of DDEV and achieve the optimal energy consumption.…”

“…The results show that the proposed method can both improve tracking performance and reduce the total power consumption. 20 Considering the research status of domestic and foreign research in recent years, most of the torque distribution methods of DDEV are only aimed at safety or economy. The torque distribution mode is single, and the torque is not based on the current driving conditions of the vehicle.…”