조각 거울 자세 제어를 위한 대변위 나노 구동기 개발

다국어 초록 (Multilingual Abstract)

In this paper, we developed of large Range Fine Actuator for the segmented mirror pose control. This actuator uses the Tumbler coupler employed in the James Webb Space Telescope (JWST) to achieve both large displacement motion and fine motion with a single actuator. The fine motion is achieved by generating a Sine waveform motion through the combination of a Compound flexure and an eccentric cam, utilizing a specific linear section of this motion for fine adjustments. The coarse motion employs a Nut moving method, achieving stable linear motion through high structural rigidity. Recognizing the time and cost difficulties in machining parts such as gears, lead screws, and bearings from materials with excellent thermal and mechanical properties, we instead fabricated the actuator using commercially available parts that can operate in extreme cold and vacuum conditions. The required torque for each stage of the large Range Fine Actuator was calculated based on the Load and Position conditions of the Coarse and Fine motion, and an appropriate Step motor was selected. The motion range of the Fine stage was set considering its relationship with the coarse motion, and a Harmonic profile, which is easier to process, was used for the cam profile. The reduction ratio of the Reducer was determined considering the motion range of the Fine stage and the lift of the cam. After the design was completed, the performance of the large Range Fine Actuator's Fine motion and coarse motion was measured and evaluated to verify its performance.

목차 (Table of Contents)

• 제 1 장 서 론 1
• 1.1 연구 배경 1
• 1.2 종래 기술: Fine Coarse dual stage 4
• 1.3 Cryogenic Nano-Actuator: NASA 6
• 1.4 연구 목적 및 내용 8
• 제 2 장 기구 설계 9
• 2.1 개념 설계 9
• 2.2 상세 설계 12
• 제 3 장 실험 절차 및 결과 21
• 3.1 Fine motion 21
• 3.1.1 실험 방법 21
• 3.1.2 Fine stage 특성 분석 24
• 3.1.3 Fine motion 구동 시 문제점 및 해결 33
• 3.2 Coarse motion 42
• 3.2.1 실험 방법 42
• 3.2.2 Lead screw 특성 분석 44
• 3.2.3 Coarse motion 구동 시 문제점 49
• 3.2.4 Tumbler coupler 의 Backlash zone 진입 시 Coarse motion 측정 56
• 3.3 Fine + Coarse motion 64
• 3.3.1 Coarse, Fine 동시 구동 원리 64
• 3.3.2 Simulator 공칭 위치 계산 및 분석 67
• 3.3.3 실험 방법 69
• 3.3.4 공칭 위치 이동 71
• 3.3.5 Tumbler coupler 의 Backlash zone 측정 73
• 3.3.6 Tumbler coupler 의 Backlash zone 진입 시 문제점 75
• 제 4 장 결론 77
• 참고문헌 80
• Abstract 82