Using fuzzy PD controllers for soft motions in a car-like robot

Abstract

This paper deals with the control problem for nonholonomic wheeled mobile robots moving on the plane, and in particular, the use of a Fuzzy controller technique for achieving a given motion task which consists of following a rectilinear trajectory until an obstacle occurs on the path. After a background part, in which the fundamental knowledge of Fuzzy control is considered, the problem of the avoidance of an obstacle is taken into consideration. When an obstacle occurs on the path, the drive assistant provides for its avoidance calculating the minimal distance from which the avoidance maneuver starts. Conditions on the parameters of a PD controller are calculated using a Fuzzy based approach. An observer is designed to obtain unmeasurable states to be used in the control loop. In the Appendix of this paper a formal demonstration of a Proposition is proven in which the convergence of the system state estimation of the observer is shown. Simulations considering a real transporter vehicle for a storage service are shown.