Two approaches to force control by rubbertuator-driven mechanism: application of IMC and SMC

The Rubbertuator has been developed as a new kind of actuator. A pair of Rubbertuators are generally used in a joint with one degree of freedom because it can generate only a unidirectional force. An experimental system and its dynamic characteristics are described. Modeling of a Rubbertuator-driven mechanism is described first, and then two methods, internal model control (IMC) and sliding mode control (SMC), are applied to the force by the Rubbertuator-driven mechanism. It is shown that the two methods can produce good performance. They are sufficiently robust to deal with model errors, process nonlinearities, and force disturbance. They are easier to tune than proportional-integral-derivative (PID) control