An approach to absolute position control of mobile robot by PSD based robust control

The purpose of this research is to realize an absolute position control of mobile robot. Several researches with respect to position control of mobile robot considering its nonholonomic constraints have already reported. They are so powerful, but there are still some issues to improve the control performance. First, the disturbances such as wheel slip, modeling error, and so on deteriorate the position response. So the disturbances suppression should be considered. Second, it is difficult to predetermine the trajectory to reach the desired position because of the nonholonomic constraints. To improve the performance of the position convergence, it is strongly required to develop the trajectory generation algorithm independently of the nonholonomic constraints. In the proposed approach, the absolute position detected by PSD is used to construct the robust position controller. Furthermore, the virtual forces to swing the mobile robot and to modify its orientation are arbitrarily generated to guarantee the convergence to the desired position even if the position response is affected by slip motion or uneven floor. Several numerical and experimental results are shown to verify the validity of the proposed approach.