A PATH TRACKING CONTROL-SYSTEM FOR AUTONOMOUS MOBILE ROBOTS - AN EXPERIMENTAL INVESTIGATION

A path tracking control system developed for autonomous mobile robots driven by wheels is described. In conventional approaches, the path is usually planned by smooth curves with curvature-continuity and a path tracking controller is independently designed to compensate the path error occurring in the navigation. However, smooth path planning is di fficult to execute on-line due to the computational burden. In additio n, the conventional path tracking algorithm often causes unpredictable tracking motion when large path error occurs. In previous work, the p resent authors presented a bang-bang path tracking algorithm by which smooth and stable tracking motion could be obtained even for the path given by simple combination of straight lines or circles and its effec tiveness was proven via preliminary simulation studies. However, there still remained the problem that the design parameter called landing c oefficient could not be optimally chosen and performance verification through real system application was not accomplished. In this study, w e improve the algorithm which can determine the design parameters anal ytically and verify its performance by implementing the algorithm in a n actual mobile robot control system designed using a personal compute r. To investigate the performance of the control system, a series of p ath tracking experiments was conducted for a two-wheel driven robot de veloped in the laboratory.