Sideslip Angle Control of Electronic-four-wheel Drive Vehicle Using Backstepping Controller

This paper presents our investigation into creating a sideslip angle control system for an electronic-four-wheel drive (e-4WD) vehicle. In keeping with the growing demand for fun-to-drive vehicles, our e-4WD vehicle, which is equipped with in-wheel motor systems (IWMs) on the front wheels and an active differential on the rear axle, is mainly aimed at improving cornering performance. The vehicle system in this paper is based on a bicycle model, which has a recursive structure in terms of the sideslip angle and yaw moment, a backstepping controller is utilized as they have proven to be effective for this kind of structure. The backstepping controller generates the desired yaw moment while its feed-forward control term actively reflects the sideslip angle reference, improving both the convergence rate and responsiveness of control actions. Then, the desired yaw moment is distributed through the IWM torques on the front wheels and shaft torques on the rear axle. A Daisy-chaining method is utilized for distribution of the IWM torques while taking into consideration practical issues. Using the simulation software CarSim, it was found that some cornering performance evaluation factors are improved in this proposed controller when compared to conventional feedback controllers.