Abstract
The actuators using shape memory alloy can work as an actuator to control or retain positioning without using sensor device. In order to utilize the shape memory effect, the external force is required to deform the shape memory alloy in martensitic phase. For a method to give an external force to, a bias mode and an antagonism mode are used. In this work, the effects of a control displacement and an external load on the positioning characteristics by an antagonism type actuator are investigated. The Ti-Ni-Cu alloy wire is used as an actuator element. The positioning characteristics such as settling velocities, position error, and position stability are discussed in relation to a control displacement and an external load. The results show that settling velocity of an antagonism in heating process is slower than those of two bias mode of a const mass and a bias spring, but in cooling process, settling velocity of an antagonism is faster than those of two bias modes. Furthermore, position error is not affected by an external load. However, position stability in heating process is affected by an external load.
