Adaptive Perturbation Suppression Control for Multiple Nonholonomic Mobile Robot Clusters Against Composite Motion Constraints

The composite velocity and acceleration constraints suffered by nonholonomic mobile robots during motion severely hamper the stability and smoothness of the cluster. This paper presents an applicable control framework for the robust and smooth implementation of distributed formations based on nonholonomic mobile robot clusters against velocity and acceleration saturation. The decoupled feedback linearization control of cascaded position, heading and wheel velocity is used to achieve distributed time-varying formations with modular and scalable stabilization of the triple-level errors. The adaptive auxiliary dynamics are incorporated into the distributed coincident errors to reduce velocity and acceleration saturation, which improves the overall transient results and stability range. The adaptive saturation extended observer in the substrate dynamics is conceived to simultaneously estimate the lumped disturbances and suppress undesired peaks, smoothly enhancing the robustness of wheel velocity control. Ultimately, comparative simulations and extensive experiments for mobile robots are performed to test validity and practicality.