Fuzzy Optimization Design of Adaptive Robust Control for Uncertain Cooperative Robots with Servo Constraints

In this paper, the reference trajectory tracking issue of cooperative robots system with bounded uncertainty is investigated from a novel standpoint of servo constraint-following. The bound of uncertainty is not known but can be characterized by the fuzzy set theory. Then, establishes the dynamical model of cooperative robots system with fuzzy uncertainty. The process of the proposed controller design contains two steps. First, an adaptive robust control is investigated which can render the desired servo constraint to be followed even if there exists uncertainty in the system, and through stability analysis by selecting appropriate Lyapunov function which proves uniform boundedness and ultimate uniform boundedness of tracking error. The second step is to find a parameter selection guideline for the optimal control parameter. Based on the fuzzy description of system uncertainty, a performance index consisting of system performance and control cost can be developed. Then, the selection of optimal control parameters translates into finding the parameter that makes the performance index minimized. Finally, numerical simulations are performed on a two-planar two-link manipulator system for evaluating the performance of the proposed method.