Basic characteristics of tendon-driven manipulator using belt pulleys

In this paper, we propose a new belt pulley mechanism based in rolling of a blade spring. This pulley can transmit wire tension by transforming itself into an ellipse. By inserting the belt pulleys into the route of wires instead of a complex mechanism, we can easily actualize a flexible tendon-driven manipulator. Internal force among the wires can drastically change the joint stiffness of the manipulator. Compared to other tendon-driven manipulators with variable stiffness, the belt pulley has some advantages such as simple design, low cost, less friction and light weight. Based on the characteristics of belt pulley, we developed tendon driven manipulators. The angle dependency is investigated experimentally though a one-link tendon manipulator. In order to overcome the difficulty of short stroke, we improved the belt pulley and developed a two-link manipulator.