Dynamic modeling of a pneumatic muscle actuator with two-direction motion

•New investigation on dynamics of a vibrating pendulum with PAM is discussed.•Dynamic model of the vibrating system based on the static force model is developed.•The model corresponds to a PAM of any length and diameter with any pressure.•It can also determine the nonlinear stiffness and damping properties of PAM.

In this paper a new dynamic model for an actuator applied as a pneumatic artificial muscle (PAM) is developed. The model simulates the two-direction motion of a PAM caused by a nonlinear force which depends on pressure and deformation. Parameters of the acting force are obtained analytically, applying the optimal parameter identification method, and experimentally proved on the model tested on an experimental rig. In the dynamic model the stiffness and also the damping are nonlinear functions of displacement. The nonlinear displacement force causes self-excited vibrations of PAM. Influence of different loadings on the system is investigated. Using MS Excel software and MATLAB Simulink the simulation of motion of the system is given.