Topological metrics for evaluating self-reconfigurable modules properties (connectivity & expansion)

It has been more than a decade since the idea of self-reconfigurable robots was developed, since then various types of these robots with different designs & topologies has been made to best achieve the ability of transformation. Although important, since then there has rarely been a common criterion to compare different properties of suggested topologies and designs. In this paper we focus on this task and develop criteria and an approach named triple metrics approach by which different properties of different designs such as expansiveness, flexibility and connectivity can be properly compared to each other. Development of expansion and connectivity criteria are main issues in this paper and flexibility criterion is briefly introduced.