The paper deals with the problem of output feedback trajectory tracking with a unicycle mobile robot system. The situation is considered in which the absolute Cartesian coordinates of the mobile robot are measured, but its orientation angle is unknown. A state-feedback controller for the nonlinear error dynamics of the robot is combined with an observer that estimates the orientation error based on available trajectory information and measurement of the position coordinates. Thus a result of Jakubiak et al. (2002) is extended. A complete stability analysis of the resulting output-feedback trajectory tracking controller is given; it proves exponential tracking. The controller is implemented on an experimental mobile robot system to test the results in real time.
Reviewer: Bojidar Cheshankov (Sofia)