Abstract: “Pneumatic artificial Muscles (PAMs) are, nowadays, widely used in factory floor automation as well as in robotics. One of the major appeals about PAMS is the high force to weight ratio as well as their light weight, structural flexibility. Furthermore, PAMS do not exhibit any mechanical wear they are relatively low in cost. However PAMs are known to exhibit hysteresis nonlinearities between the input pressure and the output force as well as the contraction ratio and the input pressure. Such nonlinearities are known to cause oscillations in the open-loop system’s responses, as well as poor tracking performance and potential instabilities. This work reviews the some of the available models used to simulate the hysteresis nonlinearities in PAMs which will facilitate to study the effects of these nonlinearities in order to characterize and to enable the design of controllers for compensating for the hysteresis effects”

Keywords: PAMs, robotics, modelling, hysteresis, nonlinearities