AN ITERATIVE LEARNING CONTROLLER FOR NONHOLONOMIC MOBILE ROBOTS

We present an iterative learning controller that applies to nonholonom ic mobile robots, as well as other systems that can be put in chained form. The learning algorithm exploits the fact that chained form syste ms are linear under piecewise-constant inputs. The proposed control sc heme requires the execution of a small number of experiments to drive the system to the desired state infinite time, with nice convergence a nd robustness properties with respect to modeling 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 obtai n a cyclic controller by which the system is cyclically steered throug h an arbitrary sequence of states. As a case study, a carlike mobile r obot is considered. Both simulation and experimental results are repor ted to show the performance of the method.