An Iterative Learning Controller for Nonholonomic Mobile Robots

Abstract

We present an iterative learning controller that applies to nonholo nomic mobile robots, as well as other systems that can be put in chained form. The learning algorithm exploits the fact that chained- form systems are linear under piecewise-constant inputs. The pro posed control scheme requires the execution of a small number of experiments to drive the system to the desired state in finite time, with nice convergence and robustness properties with respect to model ing inaccuracies as well as disturbances. To avoid the necessity of exactly reinitializing the system at each iteration, the basic method is modified so as to obtain a cyclic controller, by which the system is cyclically steered through an arbitrary sequence of states. As a case study, a carlike mobile robot is considered. Both simulation and experimental results are reported to show the performance of the method.