DESIGN OF CONTINUOUS GAIN SCHEDULED H_∞ CONTROLLER FOR ROBOT MANIPULATOR

A new approach to designing continuous gain scheduled H_∞ controllers for n joint rigid robot manipulator has been presented in this paper. The approach combines gain scheduling theory with H_∞ theory. By linearizing the system at equilibrium points and utilizing state feedback H_∞ technique with poles placement, we design state feedback gain satisfying H_∞ performance and dynamic qualities at every operated regions. The gains are fitted to continuous functions of the states of the system using taylor series expansion. With changes of the states of the system, the controller can get continuous gains using the fitted gain functions. Not only the designed controller can be applied to the plants with fast varying states, but also the system possesses always a good dynamic performance. The presented approach overcomes limitations of the conventional gain scheduling control. Simulation results prove the effectiveness of the designed controller.