  Series elastic actuators (SEA) are playing an increasingly important role in
the fields of physical human-robot interaction. This paper focuses on the
modeling and control of a cable-driven SEA. First, the scheme of the
cable-driven SEA has been proposed, and a velocity controlled DC motor has been
used as its power source. Based on this, the model of the cable-driven SEA has
been built up. Further, a two degrees of freedom (2-DOF) control approach has
been employed to control the output torque. Simulation results have shown that
the 2-DOF method has achieved better robust performance than the PD method.
