Improving Adaptive Fuzzy Control for MIMO Nonlinear Time-Delay Systems

Combining adaptive fuzzy control with adaptive fuzzy identification, this paper presents an improving observer-based indirect adaptive fuzzy control scheme for MIMO nonlinear time-delay systems. In this paper, an observer is designed to observe the system state, and an identifier is designed to identify the unknown part of the systems. By the observation error and the identification error, the parameter adjusting laws are derived. Both errors improve the performance of the system by regulating the parameters. Adaptive time-delay fuzzy logic systems are implemented to estimate the unknown functions, and a compensator eliminates fuzzy approximation errors and external disturbances. The control scheme guarantees system stability. The simulation results of 2-link manipulator demonstrate that the improving control scheme is effective.