Layered Multi Angular Gearless Transmission (L-MAGT) Mechanism for Agile Manipulation = 조작기 민첩 조작을 위한 다층 다각 기어리스 동력 전달 (L-MAGT) 메커니즘

국문 초록 (Abstract)

본 연구에서는 액추에이터와 관절을 분리 배치한 매니퓰레이터에서 사용 가능한 다축 동력전달 메커니즘을 제안하며, 이를 휴머노이드 팔에 적용하기 위해 수정된 Hobson joint 기반의 Multi Angular Gearless Transmission(MAGT)을 중심 요소로 채택하고, 세 층으로 구성된 layered MAGT(L-MAGT)를 통해 동축 입력을 전달하여 손목의 roll-yaw-pitch 3축을 구현하였다. 이 설계는 액추에이터를 말단부에 직접 장착하지 않고 팔꿈치를 관통해 손목으로 동력을 전달함으로써 말단부 질량을 경감시켜 조작 기민성을 향상시키고, MAGT 특유의 등속 특성으로 Cardan joint와 같은 universal joint에서 발생하는 속도 변동을 제거한다. 3D-프린터로 제작한 시제품과 모션 캡처 기반 실험 검증 결과, 일부 백래시와 컴플라이언스가 존재함에도 목표한 동작 범위와 반복 정밀도를 만족하여 제안한 메커니즘의 실현 가능성을 입증하였으며, 가변 각도를 갖는 관절을 통과해 다축 동력을 전달하는 매니퓰레이터 설계 솔루션을 제시하였다.

다국어 초록 (Multilingual Abstract)

This study introduces a multi-axis power transfer mechanism that is applicable when actuators and their corresponding joints are placed separately in a manipulator. In particular, in this work, the humanoid arm is considered the primary target of application. A modified Hobson joint, termed the Multi Angular Gearless Transmission (MAGT), serves as the central mechanism. The system transmits power through the elbow to the wrist without requiring direct placement of the actuator in the distal part of the manipulator. The design uses a layered MAGT (L-MAGT) to convey coaxial inputs. In this study, L-MAGT which employs three layers is applied to implement a wrist with three axes. After L-MAGT transmits inputs, the coupled wrist 3 axes structure converts them into roll, yaw, and pitch motion of the wrist. This approach reduces the weight of the actuator in the distal part of the manipulator. The weight reduction in the distal part leads to more agile manipulation of the manipulator. Furthermore, the MAGT ensures constant velocity transmission across varying elbow angles, eliminating the velocity fluctuation typically associated with universal joints, such as the Cardan joint. Experimental validation using a 3D printed prototype and a motion capture system shows that the mechanism achieves its intended range of motion and maintains acceptable repeatability, despite some backlash and compliance introduced by 3D printed components. The results confirm the feasibility of this mechanism for humanoid arms and manipulators. The proposed mechanism, which passes through a joint with variable angles, offers a multi-axis power transfer mechanism solution to manipulator design.

목차 (Table of Contents)

• 1 Introduction 1
• 2 Proposed Mechanism 7
• 3 Experiment 16
• 4 Discussion 24
• 5 Conclusion 40