SMAアクチュエータの変位量に対する応答特性の変化

抄録

In this study, we investigated the optimal conditions for achieving higher response of Ni-Ti based shape memory alloy (SMA) wire actuator. High speed driving of SMA actuators have been said to be difficult because their deformation speeds depend on temperature change; especially, cooling speed is important factor, and many studies focus on it. We had developed a method for improving the response of SMA actuators by adding DC bias to the input voltage signal. As opposed to the methods for improving cooling performance, this method has the advantage in non-necessity of external devices. In order to examine the optimum conditions, we connected SMA actuator and spring in series and conducted experiments of changing DC biases voltage applied to the single frequency input. From the result of experiments, we found that response of SMA actuator changed depending on the displacements, and the maximum response was obtained when the strain was 4.51 % in 200 Hz input signal.