Tip-Positioning Control of a Tendon-Wire-Driven Mechanism (Modeling and Reference Compensator Design)

A tip position of a wire-driven mechanism is controlled by an electric motor, so the three problems : slack in the wire, friction between the wire and coil sheaths protecting it, and change in the form of the tube must be solved. A model of the wire-driven mechanism was devised, and a method for controlling the wire-driven mechanism was then developed. First, a model base on a nonlinear dynamic equation including friction and wire slack was mode, then a reference-filter controller, which compensates the phase delay of the wire-driven positioning system, was designed. Positioning experiment was confirmed that the controller effectively improved the following performance regarding the target trajectory without the need for an additional sensor.