A robust time-delay nonlinear controller for a pneumatic artificial muscle

Abstract

In this paper, we present an effective position tracking control approach based on robust time-delay nonlinear (RTN) technique for a pneumatic artificial muscle (PAM) system. Due to the existence of uncertain, unknown, and highly nonlinear terms in the system dynamics, providing a high-accuracy controller is a challenging work. By dealing with this problem, the control strategy is as follows: first, to actively compensate for the total system dynamics with the reduction of setup cost and computational burden, a time-delay estimator is employed; to overcome the estimation error and to maintain an asymptotic control performance, robust linear and nonlinear compensators are next proposed under sliding mode scheme; convergence of the closed loop system is then confirmed by Lyapunov-based theoretical proof. Effectiveness and feasibility of the designed controller were successfully verified on a real-time PAM system under different working conditions.