Fuzzy continuous gain scheduled H∞ control based on Taylor series fitting for robotic manipulators

A new approach to the design of a fuzzy continuous gain scheduled H-infinity controller based on Taylor series fitting for n-joint rigid robotic manipulators, which guarantees satisfactory dynamic characteristics in the whole movement range, is presented. This scheme combines the gain scheduled H-infinity theory with the Linear Matrix Inequalities (LMI) approach to design a continuous gain scheduled H-infinity controller, which is applicable to systems with fast state variations so that the deficiency of the coventional gain scheduled controllers is overcome, with the use of Taylor series fitting. Fuzzy control is then incorporated so that the design controller possesses the characteristics of a fast response for large errors and a well-damped response for small errors. The system thus always has a good dynamic performance along with the variations of the system states. Simulations and experiments demonstrate the effectiveness of the designed controller.