A Modified Bouc-Wen Model of Pneumatic Artificial Muscles in Antagonistic Configuration

Pneumatic Artificial Muscles (PAMs) exhibit hysteresis, nonlinear, and uncertain characteristics. This makes it difficult to build a highly precise model of PAM. In this study, a modified Bouc-Wen model is used to describe the hysteresis in the relationship between internal pressure and joint angle of PAMs in the antagonistic configuration. Through an identification method using particle swarm optimization, it is verified that the proposed model can approximate the behavior of PAM based antagonistic actuator with high accuracy. This could lead to enhancing the tracking performance of PAMs.