Event-triggered adaptive fuzzy optimal control of modular robot manipulators using zero-sum differential game through value iteration

In this article, a novel event-triggered zero-sum differential game through value iteration (VI)-based adaptive fuzzy control is proposed for modular robot manipulators (MRMs) with uncertain disturbance. The subsystem dynamic of MRMs is established by joint torque feedback (JTF) technology. An identifier based on fuzzy logic model (FLM) is established to identify unknown system dynamics. Then, the trajectory tracking control issue of MRMs with uncertain disturbance is transformed into a two-player zero-sum differential game. On the basis of event-triggered mechanism and VI algorithm, the event-triggered Hamilton-Jacobi-Issacs (HJI) equation is approximately solved through establishment of actor-critic structure. Different from the traditional adaptive dynamic programming (ADP) algorithm, this scheme is based on adaptive fuzzy optimal control through an actor-critic structure, which refers to adaptation of both optimal cost function and optimal control policy. Moreover, tracking errors of closed-loop MRM system are demonstrated to be uniformly ultimately bounded (UUB) under Lyapunov stability theorem. At last, experimental examples and comparisons show the reliability and effectiveness of this method.