Mobile robot guidance control with nonlinear observer based state estimation

This study focuses on a mobile robot guidance control system in which a mobile robot tracks the reference trajectory parallel to a guide wall. A laboratory mobile robot which has two driving wheels and two distance measurement sensors on each side to measure distances from the guide wall is considered. Because measured distances are influenced by noise such as guide wall undulations and mobile robot vibrations, a nonlinear observer based on the extended linearization method is adopted to estimate state variables in mobile robot motion dynamics. A mobile robot heading angle and lateral deviation estimation algorithm based on this nonlinear observer are proposed, and the observer stability condition is derived. The estimation algorithm combined with state feedback controller comprises the mobile robot guidance control system. Estimation and control performance of the system are evaluated with a simulation model and the laboratory mobile robot.