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

Abstract

SummaryIn 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.

Dynamic triggered‐based tracking approach for connected vehicle system via extended observer

“…The event trigger mechanism can be used to replace the fixed time step sampling, which can reduce the sampling frequency and improve the system performance. Based on the backstepping control law (23), we combine the event trigger mechanism to design the final control law below:…”

“…▪ Theorem 3. Considering ESO in (7), backstepping control law (23), and dynamic event trigger mechanism (34), (35), and (36), all signals in vehicle system ( 5) can be ultimately uniformly bounded, and Zeno behavior does not occur.…”

“…[19][20][21] Different from the traditional fixed cycle trigger, the update and sampling of the controller by the event trigger mechanism depend on specific trigger rules, which can significantly reduce the burden and consumption of network resources, and maintain the ideal performance at the same time, therefore, many researches related to this have been carried out. 22,23 It should be noted that in order to verify the effectiveness of the event triggering mechanism, it is necessary to prove that Zeno behavior does not occur, Zeno behavior refers to that in event triggered control, relevant signals are triggered infinitely in a limited time. In reference 24, event triggered control is used to reduce communication costs.…”