3PAC: A Plug-and-Play System for Distributed Power Sharing and Communication in Modular Robots

In modular robotics, there is classically a compromise between coupling complexity and functionality. The mechanical and electrical designs are linked, such that adding electrical features often requires redesigning the mechanical components. However, increasing the functionality of each electrical contact adds capabilities or redundancies to existing robots without redesigning the coupling and allows for fewer contacts in new designs. This article presents a power distribution and local communication system for modular robotics, using only three electrical contacts between modules. The proposed system can be easily recreated, modeled, and outfitted into an existing modular robotic coupling to introduce power sharing, communication, or redundancy, without increasing the couplings mechanical complexity. By focusing on local power transfer, the system is scalable in number as well as coherent with modularity. We demonstrate that, through this system, distributed power sharing can improve the runtime of a simple modular robotic system by up to 62% while maintaining local communication streams. The circuit is modeled through empirical characteristics and therefore the same methods can predict the power distribution accurately in any other modular robot.