Dynamitic model and stability analysis of force-driven series elastic actuator

Dynamitic model of force-driven series elastic actuator is established in this paper. The driven source is considered to be an ideal force source and the elastic component is considered to be a parallel link of a damper and a spring. Transfer function is derived using Laplace transform. Furthermore, Bode and Nyquist diagrams are illustrated using the transfer function to show the characteristics in frequency domain and the stability of the model. The step and sinusoidal responses of the system are simulated using control and dynamitic simulation software. The experiments are accomplished using DSpace and SEA prototype. It is proved by the above simulations and experiments that the model established in this paper is accurate.