물리적 인간-로봇 상호작용 시스템을 위한 안전 조인트의 개발

To achieve a safe joint, passive compliant elements such as springs and dampers are preferred to active elements because they can provide fast and reliable performance. However, nonlinear stiffness adjustment of springs is difficult. In this study, a safe joint using the differential gear instead of elastic elements is proposed in order to reduce human injuries in the robotic workspace. If a manipulator linked with one of the output shafts is restrained by external loads, the shaft will not rotate and another shaft will rotate with two times of an input speed; so humans who collide against the manipulator can be safe with the proposed joint. In addition, after the remove of external loads, the proposed joint can work immediately toward target angles. The experimental results show that the proposed joint provides sufficient safety and fast responses. The joint can be applied to a lot of manipulator which require safe interaction with humans.