Mechanism and Control of a 7 D.O.F. Tendon-Driven Robotic Arm with NST.

摘要

If a robot arm which has similar characteristics to human arm is realized, it will open new possibilities in the application of robots. One typical example of such characteristics is viscous-elasticity adjustability. A human arm has muscles far more than the D.O.F. and can adjust the joint stiffness at will. This property allows us to perform various tasks successfully. In this paper, to design a robot which can work with human beings cooperatively, comfortably and safely in the same area, a tendon-driven manipulator which has the following properties is developed. 1. It has 7 D.O.F. and the linkage configuration as well as the dimensions are similar to a human arm. 2. It has ten tendons together with no-linear spring tensioning devices (NST) which make it possible to adjust the mechanical joint stiffness over a very wide range. Using these properties, the robot can match the impedance with the environment including a human coworker and do various tasks effectively.The mechanism and control problems of the 7 D.O.F. tendon-driven robotic arm with non-linear spring tensioning devices are discussed. Several experimental results are also given to show their efficiency.