Variable Impedance Control of Cable Actuated Continuum Manipulators

Continuum manipulators are a class of special compliant robots that have important potential applications in the field of human-machine interactive operations, or work in cluttered and constrained environments. In these application scenarios, the most popular operation tasks are those with coupling force-position constraints. To simultaneously stabilize the desired operation force and the position of the manipulator, variable impedance control issues of the cable driven continuum manipulators are investigated in this paper. On the basis of constructing a novel Lyapunov function, a variable impedance control law is presented and the stability of the closed-loop system has also been analyzed. Then the operation space variable impedance control for a single segment cable driven continuum manipulator is realized by the aid of a pseudo-rigid-body model. Some numerical simulations also demonstrate the stability of the variable impedance control system.