Wrench Recovery of Parallel Manipulators for Full Retrieval of Subtasks

Abstract

In this paper, the wrench recovery of parallel manipulators after actuator failure is investigated. To achieve the desired wrench capability, the mobile platform task is divided into the recoverable and non-recoverable subtasks. The presented work is based on the projection of the lost wrench due to total or partial actuator failure onto the range space of the reduced Jacobian matrix. The force/torque of the healthy joints is adjusted such that the secondary goal comprising the 2-norm of the error of non-recoverable wrench and the 2-norm of the vector of the overall forces/torques of the healthy joints is minimized without affecting the recovered components of the wrench.