Lyapunov fuzzy Markov game controller for two link robotic manipulator

Abstract

Markov game based controllers are robust but lack guarantee on the stability of the designed controller. In this work, we attempt to address this shortcoming by proposing a lyapunov fuzzy Markov game controller for safe and stable tracking control of two link robotic manipulators. Lyapunov theory has been used to generate fuzzy linguistic rules for implementing a reinforcement learning (RL) based Markov game controller. We employ fuzzy inference system as a generic function approximator to deal with the “curse of dimensionality” issue. Proposed RL based Markov game controller is self-learning, adaptive and optimal. We implement the proposed control paradigm on: a) Two link robot manipulator and b) SCARA manipulator for the cases: i) controller handles disturbances and parameter variations, and ii) disturbances and no parameter variations. We give comparative evaluation of our approach against: a) fuzzy Q learning controller, and b) fuzzy Markov game controller. Simulation results illustrate stable and superior tracking performance and advantage in terms of lower control torque requirements.