Backstepping variable structure control of slip-based kinematics and dynamics for improved AGV cornering performance

Tracking accuracy in ground vehicle path following is an important topic addressed by vehicle steering control. While several controllers exist, this controller aims to provide improved path following while cornering on sloped terrain. Towards this goal, this work develops a new kinematic controller that considers the effect of slip and a new dynamic controller that better compensates modelling error and actuator disturbances. The kinematic controller uses a new kinematic model and applies backstepping architecture with variable structure control manifolds to assure smooth and graceful yaw rate commands. The dynamic controller is also based upon backstepping, but introduces integrator states to the architecture and derives a new controller to improve yaw rate tracking. Simulations and field experiments demonstrate resulting performance improvements, which are compared to prior work to highlight contributions of this work.