The impact of module morphologies on modular robots

Many different types of modular robots have been designed in the last two decades. However, limited research has been done on analyzing which module morphology is able to create better robots for a given task. To address this issue, this paper investigates how the number and position of available connection faces in a module influence the evolvability of the modular robot. In contrast to previous research on modular robots, an analysis of the morphology of the module is done in order to improve and simplify its mechanical design. To this end, we designed a homogeneous module called EMeRGE, and defined the number of connection faces and their relative positions as morphological parameters. Afterwards, we evolved the morphology and control of robots composed of EMeRGE modules in a robotic simulation platform. Simulation results indicate that robots containing modules with only two available connection faces were able to acquire better performance than robots that contained modules using more connection faces for a locomotion task. Finally, the simulated robots were transferred to the real world in the actual modular robot to verify the simulation results.