Synthesis Methodology for Task Based Reconfiguration of Modular Manipulator Systems

In this paper, we deal with two important issues in relation to modular reconfigurable manipulators, namely, the determination of the modular assembly configuration optimally suited to perform a specific task and the synthesis of fault tolerant systems. We present a numerical approach yielding an assembly configuration that satisfies four kinematic task requirements: reachability, joint limits, obstacle avoidance and measure of isotropy. Further, because fault tolerance is a must in critical missions that may involve high costs if the mission were to fail due to a failure in the manipulator system, we address the property of fault tolerance in more detail. Initially, no joint limits are considered, in which case we prove the existence of fault tolerant manipulators and develop an analysis tool to determine the fault tolerant work space. We also derive design templates for spatial fault tolerant manipulators. When joint limits are introduced, analytic solutions become infeasible but instead a numerical solution procedure can be used, as is illustrated through an example.