Tracking control of pneumatic muscle using Lyapunov based control method

Presently pneumatic muscles (PMs) are used in various applications due to their simple construction, lightweight and high force to weight ratio. However, pneumatic muscles are facing various problems due to their nonlinear characteristic in various mechanical applications. The model of PM is nonlinear and time-varying. In this paper, a Lyapunov-based control (LBC) approach is proposed for the control of PM. Based on the nonlinear characteristic of PM, a dynamic model of the PM actuator with pulling a mass against gravity is formed. Control objectives are both a regulation and an asymptotic tracking of a desired trajectory. Stability analysis based on Lyapunov method with respect to our proposed control law is discussed. The simulation results show the validity, effectiveness and enhancing robustness of the proposed method.