Hybrid modeling of McKibben pneumatic artificial muscle systems

This paper presents a hybrid modeling method for a pneumatic artificial muscle that vertically suspends a mass. The modeling mainly consists of mechanical and hydrodynamic equations and is developed with empirical modifications. A feature of this approach is that it allows the model to include if-then formulation and nonlinearity such as flow dynamics and friction. And the model includes a novel mass flow model which allows the mass flow rate to converge to zero in steady-state operation. Furthermore, in order to show validation of the obtained hybrid model using a practical testbed system of the PAM we made.