On the effort of task completion for partially-failed manipulators

Abstract

Adding to a previous work of the authors for task completion for partially failed manipulator, other aspects of the effort are discussed. The paper aims to investigate on the strategies of maximum effort for maintaining the availability of partially failed manipulators. The failures are assumed as the joint lock failures of the manipulators. The main objective is to facilitate the existing manipulators to continue their tasks even if a non catastrophic fault occurs into their joints. The tasks includes motion tasks and force tasks. For each group of tasks a constrained optimality problem is introduced. Then in a case study a required force profile on a desired trajectory using a 3DOF planar manipulator is indicated. Through this study the joint angles and joint torques for a healthy manipulator and a faulty manipulator are shown. It is illustrated that a failure in the second joint is tolerated on the trajectory of end-effector