Pulse width modulation modeling for efficient pneumatic artificial muscle control

Abstract

The aim of the article is to analyze the properties of artificial muscle system and effectiveness evaluation of the application of pulse width modulation in terms of improving the dynamic properties. In terms of dynamic properties, pneumatic artificial muscles represent a very complicated nonlinear structure. For this reason, the design of a robust positioning control system for pneumatic artificial muscle devices is demanding because, apart from the above-mentioned nonlinearity (because of air compressibility, air flow variability through valves, etc.), this is a time-and-parameter invariant system. The aim of the article is to evaluate the influence of pulse width modulation in pneumatic artificial muscle systems with regard to the accuracy and stability of the position achieved in the repeat mode, as well as the elimination of the adverse effect of the oscillation. The efficiency of the proposed control algorithm is demonstrated by experiments with external workload and no load.