Adaptive Inverse Control of Cable-Driven Parallel System Based on Type-2 Fuzzy Logic Systems

This paper is concerned with the problem of type-2 fuzzy adaptive inverse control for a cable-driven parallel system. Based on the heuristics and prior knowledge of the system, the system is divided into six subsystems. The proposed control scheme for each subsystem contains a forward model and a fuzzy adaptive inverse controller (FAIC), which are expressed by an interval type-2 fuzzy nonlinear autoregressive exogenous (NARX) model, respectively. To construct the antecedents of the interval type-2 fuzzy NARX forward models and FAICs, the monotonic property of the fuzzy NARX model is first proved, and then, their antecedent parameters can be determined by this property. Furthermore, the consequent parameters of the forward models are computed offline via a constrained least squares algorithm, and the consequent parameters of the FAIC are adjusted online via a recursive least squares algorithm. Experiment results are provided to show that the proposed type-2 fuzzy control scheme can realize the control objectives and achieve a good control performance.