A piecewise affine system modeling approach of thin McKibben muscle servo actuator

Abstract

Dynamic characteristic of thin McKibben muscle has not yet been fully investigated. Therefore, the objective of this study is to propose a piecewise affine system to model a thin McKibben muscle servo actuator. The static and dynamic modeling of the actuator has been performed using first principle approach. Different models for extension and retraction operations have been presented. The step input responses of the model have been simulated and compared to the actual system response. Result shows that the model’s response is similar to the actual system with steady-state errors of 1.18% for 0.2 MPa input and 0% for 0.25 and 0.3 MPa inputs. The evidence from this study suggests that a piecewise affine system can be used to model a thin McKibben muscle servo actuator, which would facilitate future development of a novel switching controller.