Application of Shape Memory Effect to Digital Control Actuator

抄録

An actuator made of a Ti-Ni spring and a plastic wire, to which the Shape Memory Effect (SME) is applied has been developed. The recovery process is controlled by a electrical pulse heating. The movement of the actuator is controlled sequentially by changing the pulse width. Instead of the conventional potentiometer, the actuator is positioned by feed back control utilizing the relation between the recovery strain and electric resistance change of Ti-Ni alloy during the process of SME. The actuator has been structurally simplified and miniaturized since it consists of materials and electric device. It has been found that it operates within ±2% positioning error without any overshoot by this feed back control.