Development and verification of simple tension distribution considering tension limits for 2-joint arm with 3 pairs of 6 tendons

Safety and general versatility are necessary for robots to perform various tasks in human living area. There are tendon based manipulators with nonlinear springs as a manipulator for the requirement. Tension distribution which converts from joint space to tendon space are necessary to control such tendon mechanisms. A conventional tension distribution method using pseudo inverse matrix or inverse matrix of jacobian can not consider tension limits. On the other hand, advantages of structures utilizing bilogical extremities attract much attention. In this paper, we focus on an advantage of musculoskeletal model which contributes to simple algebraic calculation when deriving tension commands. And we develop a tension distribution method which can consider tension limits for musculoskeletal model of biological extremities. Its effectiveness as a part of whole control system is verified by simulations.