Abstract Four-wheel-drive electric vehicles (4WD Evs) utilize in-wheel electric motors and Electro-Hydraulic Braking system (EHB). Then, all wheels torque can be controlled independently, and the braking pressure can be controlled more accurately and more fast than conventional braking system. Because of these advantages, 4WD Evs have potential applications in control engineering. In this paper, the in-wheel electric motors and EHB are applied as actuators in the vehicle stability control system. Based on the Direct Yaw-moment Control (DYC), the optimized wheel force distribution is given, and the coordination control of the hydraulic braking and the motor braking torque is considered. Then the EHB hardware-in-the- loop test bench is established in order to verify the effectiveness of the vehicle stability control algorithm through experiments. The simulation and experiment results show that the stability control system with in-wheel electric motors and EHB as actuators can improve the stability of the 4WD Evs effectively. Introduction Electric vehicles (EVs) have attracted attention because they are a promising solution to energy and environmental problems. In addition, for 4WD Evs, each wheel is driven individually by in-wheel-motors. Independent driven wheels provides another steering control input, i.e. the torque steering, which can be used in vehicle stability control system to generate the yaw moment. Besides, the EHB in electric vehicle can control the braking pressure more accurately and more fast than conventional braking system. Because of these advantages, not only conventional control methods can be easily implemented, but also some advanced control strategies can be realized in stability control system for 4WD EVs with EHB. The most commonly used control method of stability control system is referred as Direct Yaw-moment Control (DYC). It has been proved that DYC is more effective in enhancing vehicle stability than four wheel steering [ 1]. Actually, the yaw moment resulting from difference in longitudinal tire force of left and right wheels are less influenced by lateral acceleration [ 2]. For 4WD Evs, the fundamental control method of stability control system is also the DYC method. At present, researches mainly focused on the optimization of yaw moment control and wheel torque distribution methods. Some advanced methods are explored for optimal yaw moment control [ 3, 4, 5, 6]. In some literatures, the problem of what the wheel force should be distributed to generate the required yaw moment is considered [7, 8]. To take full advantage of the adhesion potential of each wheel, wheel forces distribution method to make the tire adhesion utilization rate minimum is proposed. As the stability control algorithm has been much discussed, this paper is focused on the specific application of in-wheel- motors and EHB in stability control system. Based on the DYC method, optimized wheel force distribution is given, and the coordination control of the hydraulic braking and the motor braking torque is considered. Since the control of in-wheel- motor is quite complex and it is difficult to establish the model and the experimental environment. So the consideration of motor control in this paper is relatively simple. For the other actuator, EHB model and hardware-in-the-loop test bench are established. Firstly, the simulation of the vehicle stability control algorithm is studied by use of the four-wheel-drive electric Stability Control of Four-Wheel-Drive Electric Vehicle with Electro-Hydraulic Braking System2014-01-2539 Published 09/28/2014 Dongmei Wu, Haitao Ding, and Konghui Guo Jilin Univ. Yong Sun China Automotive Technology and Research Yang Li Jilin Univ. CITATION: Wu, D., Ding, H., Guo, K., Sun, Y. et al., "Stability Control of Four-Wheel-Drive Electric Vehicle with Electro- Hydraulic Braking System," SAE Technical Paper 2014-01-2539, 2014, doi:10.4271/2014-01-2539. Copyright © 2014