Path planning for self-reconfigurable modular robots: a survey

Abstract

Self-reconfigurable modular robots (SRMRs) are a special type of robots that can change their shapes and functions according to different tasks and environments. Such a robot is usually constructed using connected modules, each of which can encapsulate a simple function independently and also communicate with each other. Complex tasks can be completed by those connected modules collaboratively. In recent years, SRMRs have attracted considerable attention from both the academia and industry because of their versatility and flexibility. The path planning problem for the transformation of an SRMR is an important but not a well-solved problem, which can be considered as finding an optimal path in the configuration space where every point represents a feasible configuration of the SRMR. To provide a systematic overview of this research, we review the existing approaches considering five different aspects of SRMRs, including the type of motion on a single module, hardware for different motions, connectivity between modules, representation of a configuration space, and path planning algorithms. Aiming at motivating more research into SRMRs, the problems in existing approaches are analyzed and challenges in future work are summarized at the end of this paper.