Design of a stable controller for accurate path tracking of automated guided vehicles systems

This paper deals with the path tracking and stability of motion of automated guided vehicle systems and wheeled mobile robots. A two degree-of-freedom dynamic model is developed to represent the plane motion of the vehicle. This model along with the instantaneous posture errors (position and orientation errors) of the vehicle are used to formulate their path-tracking problem in state space format. Implementation of stability criterion and application of the actual physical limits of the pertinent parameters of the system are the strategies used to design the controller. It is shown that implementation of a control strategy based on the vehicles’ position and orientation errors gives satisfactory results in vehicles’ path tracking. The feasibility of the approach and the performance of the controlled system are demonstrated by using a prototype vehicle.