Path controller implementation for an autonomous mobile robot

This paper proposes an implementation of a path controller for an autonomous mobile robot. The problem of controlling mobile vehicles lies in the fact, that such systems have three degrees of freedom but only two control inputs. By introducing a reference path with velocity profiles for translation and rotation the path controller has to ensure that the autonomous mobile robot tracks the reference path. Classical linear control methods cannot be used because the system is nonlinear and nonholonomic. Using a canonical state space model of the linearized kinematic model of the robot a controller is designed by pole assignment. There is a demand for a simple tool which allows rapid and easy implementation of controllers on generic real systems. To satisfy this demand we have developed a real-time environment founded on the simulation toolbox Simulink of the package MATLAB. With experimental results the high accuracy of the closed loop system is shown. Even for great initial disturbances the controller is able to achieve tracking of the reference path.