Particle-Swarm Backstepping Control for Angle Tracking of Electric Motor Steer-by-Wire System

Electric motor steer-by-wire (EMSbw) for full self-driving vehicles requires precise tracking of angle demand in the process of steering, making steering angle rapid response paramount. This is particularly challenging for steering wheels precisely without handwheel, for which external disturbance information is scarce. While much of the research on steer-by-wire has focused on improving the stability of vehicle dynamics, comparatively little is known about the steering angle demand control of full self-driving vehicles. Here, we discuss a series of studies on the electric motor steering that collectively design an angle demand control approach of how the particle-swarm backstepping control (psBSC) algorithm steers the front wheels. The designed approach can not only cope with the system uncertainties in the plant model but also obtain the optimized stepping control parameters (SCPs) in the backstepping scheme effectively. The developed approach has been downloaded into a steering control unit (SCU) and tested in real-world conditions using steering test vehicle to fully realize practical application of electric motor steering.