Anti-Disturbance Direct Yaw Moment Control of a Four-Wheeled Autonomous Mobile Robot

Profiting from its remarkable maneuverability and efficiency, the four-wheeled autonomous mobile robot (FAMR) is appealing for intelligent manufacturing and automation applications. However, the suppression of unknown disturbances and system uncertainties remains a challenge for formulating a precise trajectory-tracking control scheme. This paper achieves the anti-disturbance direct yaw moment control of a developed FAMR by proposing a robust super-twisting sliding mode controller (RSSMC) to enhance the dynamic tracking and disturbance rejection property simultaneously. One of the major contributions is that the presented RSSMC method is constructed with a novel reaching law to eliminate the matched perturbations and time-varying lumped disturbances. As another distinguishing feature, this method is capable of driving the resultant FAMR trajectory into a bounded switching region and maintaining it therein for subsequent periods in finite time. To guarantee the closed-loop stability and finite-time convergence, new sufficient conditions for specifying the variable gains are determined utilizing Lyapunov functions. Finally, under the direct yaw moment control framework, simulation experiments of a developed FAMR system are offered to verify the practicability of the RSSMC scheme.