Parametric function based fuzzy tuned path-following controller for nonholonomic mobile robotic systems: Experimental performance and analysis

Abstract

This research introduces a unified parametric output function based control law for autonomous navigation of nonholonomic Wheeled Mobile Robots (WMRs) through various predefined paths, such as straight line, circular, elliptical, square, rectangular, and their combinations, achieved by adjusting parameters. This approach simplifies path-following control paradigm by eliminating the need for generating separate output functions and relevant independent decoupling matrices for each path. Uncertainties of WMR are considered and embedded within the control framework. Analytical proof is provided to ensure the existence of the control law, which is proposed for the new framework using the unified parametric function that represents various paths, for all time. Further, a fuzzy rule-base driven gain parameter scheduling framework is adopted for efficient real-life implementation of the controller, avoiding actuator saturation. After successfully achieving the desired performance maneuver in a simulated environment, experiments are conducted for validation. A Pioneer P3-DX WMR is utilized to implement the control law towards maneuvering through aforementioned paths generated by the unified function, which is relevant in robotic applications. The WMR demonstrates the ability to navigate effectively with higher accuracy along the aforementioned paths at varying velocities, including zero velocity. The zero velocity feature helps to accomplish the required functionality, such as picking up an object, at an intermediate step, thus surpassing traditional trajectory tracking methods. Eventually, the unified function based path following control framework outperforms several existing controllers, especially for paths that are subjected to substantially large curvature at some portions, as illustrated through experimental performances and subsequent quantification.