Event-Triggered Controller Design of a Pneumatic Muscle Joint System with Dead-Zone Input

In this paper, an event-triggered adaptive controller is designed by backstepping techniques for a pneumatic muscle joint system with dead-zone input. In addition to unknown dead-zone parameters, unknown system parameters and unknown nonlinear terms caused by the unknown modelling error and external disturbance are also considered. We proved that for any signal, the error between the signal obtained by the trigger signal after dead-zone transformation and the signal obtained by direct dead-zone transformation is bounded by an unknown constant. This error and the error generated by the linear approximation of the dead-zone are handled together as a disturbance-like term. These uncertainties will be compensated for by estimating the upper bound of the disturbance-like term. It is shown that the proposed event-triggered adaptive controller can ensure all signals in the closed-loop system bounded and the tracking error can converges to zero. Finally, simulation studies are used to verify the effectiveness of the proposed scheme.