27. Reconfiguration Analysis of a Fully Reconfigurable Parallel Robot

This paper presents a new method for the topological reconfiguration of a parallel robot. Using the existing structure of a full six degree-of-freedom parallel robot, limited mobility modes can be realized easily without the need to remove branch modules from the robot structure. Instead, branch modules are reconfigured from an unconstrained-active to a constrained-passive state by means of hybrid active/passive motors and reconfigurable universal-to-revolute joints. In doing so, the robot is capable of assuming a configuration that uses only the degrees-of-freedom required to complete a given task. However, due to the system setup, there are multiple candidate configurations available, each with its own workspace and reach capabilities, thus guidance is needed in selecting the appropriate configuration. An isomorphic and workspace analysis are performed to identify the capabilities of each configuration. To accomplish this, a branch-based mobility analysis, and a parametric kinematic constraint equation are formulated. It is shown that limited mobility modes with different isomorphic configurations can be synthesized automatically with this method.