Adaptive fuzzy PID sliding mode controller of uncertain robotic manipulator

Abstract

This paper presents a novel adaptive fuzzy sliding mode controller (AFSMC) that combines a PID sliding mode control (SMC) and adaptive fuzzy control (AFC) for robotic manipulator in the presence of uncertainties and external disturbances. First, the controller is developed based on PID sliding mode framework. Then, two fuzzy logic systems are applied, a fuzzy logic system is used to replace the discontinuous control term, and an adaptive fuzzy inference engine is utilized to approximate the unknown term in the equivalent control part of SMC. Thus, the system not only can handle the large uncertainties and does not require the knowledge of their upper bounds to be known in advance, but can also attenuate the chattering phenomenon in conventional SMC without degrading the system robustness. Finally, the simulation results of a two-link robot manipulator are presented to demonstrate the effectiveness of the proposed control method.