No abstract

We design, fabricate and test a non-explosive separation actuator(NEA) that can replace the pyro-type device. Considering installation space, generative force, actuation time and shock level due to actuation, the proposed NEA employs a wire-type shape memory alloy(SMA). Through theoretical analysis and experiment, the specifications of the SMA wire to activate the separation device are determined. Then, an NEA with two wire-type SMAs is fabricated to activate two times. One is the primary actuator and the other one is redundant in case the primary actuator fails. In order to increase the reliability of the device, operation tests are performed more than 10 times. In addition, a release shock test under zero gravity condition was also carried, and this testrevealed very low shock compared to that of the pyro-type device. Conclusively, we developed an NEA that can operate reliably within 0.7 sec while generating less than 30G in the shock response spectrum(SRS).

This paper describes development of a non-explosive separation device which can be equipped on small satellites. The spur geared micro DC motor, which has high reliability and advantage of price, is adopted as an actuator. The proposed separation device has resettability and it does not need extra jig to reload. In addition, the simple structure makes it easy to fabricate and assemble. To verify the performance of the proposed device, the response time tests, maximum preload tests and maximum shock level tests were performed. Also, through the vibration tests and thermal vacuum tests, feasibility of the proposed separation device was shown in launching and space environments. Therefore, we expect that the proposed separation device can replace the imported separation devices in near future.

Recently, a piezo actuator based linear motor has been actively studied because of its higher power density, compactness and quick response. However, the characteristic of small displacement makes the application of a piezo actuator limitative. In order to overcome this limitation, some actuation mechanisms using a piezo actuator are designed by bi-metal composite or more than two piezo actuators. Therefore, it enables to generate large displacement and have high resolution. In the proposed piezo motor, we have designed a bi-directional linear motor that can be operated by only one piezo actuator. In addition, it is activated with low frequency of the applied voltage, since, we utilize first mode shape of structure of motion generator to vibrate. Finally, moving direction can be simply controlled by changing the ratio of input frequency to natural frequency of structure of motion generator.