Redundancy resolution and control of manipulators driven by antagonistic pneumatic muscles

Pneumatic artificial muscles feature lightweight and compact construction, in combination with high obtainable forces and an intrinsic compliance. This makes them well suited for the actuation of kinematically redundant manipulators, but due to the limited deflection of the single muscles and the highly nonlinear static and dynamic characteristics, a whole new set of challenges arises. In this contribution, redundancy resolution and control strategies are presented, which take the main actuator non-linearities into account to make effective use of the advantages provided by the pneumatic muscle actuators. The presented approach is demonstrated on a manipulator consisting of modular segments each actuated by a pair of antagonistic pneumatic muscle actuators. The approach proves to allow the avoidance of the pressure- and deflection-dependent joint limits to ensure a maximum of controllability of the manipulator at each point in the workspace.