passive pulley
Design and Development of a Remotely Wire-Driven Walking Robot
Hattori, Takahiro, Kawaharazuka, Kento, Okada, Kei
Operating in environments too harsh or inaccessible for humans is one of the critical roles expected of robots. However, such environments often pose risks to electronic components as well. To overcome this, various approaches have been developed, including autonomous mobile robots without electronics, hydraulic remotely actuated mobile robots, and long-reach robot arms driven by wires. Among these, electronics-free autonomous robots cannot make complex decisions, while hydraulically actuated mobile robots and wire-driven robot arms are used in harsh environments such as nuclear power plants. Mobile robots offer greater reach and obstacle avoidance than robot arms, and wire mechanisms offer broader environmental applicability than hydraulics. However, wire-driven systems have not been used for remote actuation of mobile robots. In this study, we propose a novel mechanism called Remote Wire Drive that enables remote actuation of mobile robots via wires. This mechanism is a series connection of decoupled joints, a mechanism used in wire-driven robot arms, adapted for power transmission. We experimentally validated its feasibility by actuating a wire-driven quadruped robot, which we also developed in this study, through Remote Wire Drive.
A Universal Wire Testing Machine for Enhancing the Performance of Wire-Driven Robots
Suzuki, Temma, Kawaharazuka, Kento, Okada, Kei
Abstract-- Compared with gears and linkages, wires constitute a lightweight, low-friction transmission mechanism. However, because wires are flexible materials, they tend to introduce large modeling errors, and their adoption in industrial and research robots remains limited. In this study, we built a Universal Wire T esting Machine that enables measurement and adjustment of wire characteristics to improve the performance of wire-driven mechanisms. Using this testing machine, we carried out removal of initial wire stretch, measurement of tension transmission efficiency for eight different diameters of passive pulleys, and measurement of the dynamic behavior of variable-length wires. Finally, we applied the data obtained from this testing machine to the force control of an actual wire-driven robot, reducing the end-effector force error . Compared with gears and linkages, wires offer a low-friction, low-inertia transmission mechanism.