Parametric Output Function based Path Following Controller For Nonholonomic Robotic Systems

Abstract

Nonholonomic wheeled mobile robots (WMRs) are being used for various applications starting from survey to surveillance. Few of these applications demand autonomous movement of the WMR through various predefined paths like circular, elliptical, straight line, rectangular, and square shaped paths in an input-output feedback linearization based path-following control framework. Basic difficulty is that there is a requirement of defining an individual output function for each type of aforementioned path, which leads to a loss of user-friendliness. Based on the desired path to be tracked, it is also repeatedly required to derive and analyze the decoupling matrix, which is normally computationally complex, for individual path based output functions. In this article, a unified parametric output function based path following controller is proposed and subsequently designed to maneuver the WMR along various smooth (Circular, Elliptical etc.) and non-smooth (Rectangular, Square etc.) geometrical paths through variation of parameters only. The function further augments the capability of generating a unique parametric decoupling matrix. Non-singular parametric decoupling matrix also ensures the existence of the input-output feedback linearization based path-following control law. The proposed unified framework brings user-friendliness, reduces mathematical complexity and shows better simulated performance compared with the existing individual path definition based path-following as well as traditional trajectory tracking control schemes, when applied to nonholonomic WMR.