M-Blocks : three dimensional modular self-reconfigurable robots

Abstract

This thesis details the development of the 3D M-Blocks modular robot system. Modular self-reconfigurable robots (MSRR) are robotic systems which contain many modules that can form and break connections with other modules, and move on a lattice of other modules in order to form different configurations. The 3D M-Blocks is a new system which attempts to investigate the feasibility of using inertial actuation from reaction wheels in order to pivot modules on a 3D lattice. Many existing systems described in related literature are able to exhibit reconfiguration, but usually these systems are only able to do so under limited circumstances, e.g. they only work in 2 dimensions or in the absence of gravity. The 3D M-blocks is one of the only systems which is able to move modules according to a general lattice movement model in full three dimensional space under the effects of gravity. The 3D M-Blocks rotate relative to one another through the use of temporary magnetic hinges, and form bonds with each other through the use of permanent magnets. Rules describing the movement framework under which the modules move, called the Pivoting Cube Model (PCM), are discussed in depth. Each 50 mm 3D M-Block module contains all of the components necessary to operate autonomously and communicate over WiFi. Each module contains a cubic frame which supports the rotation and magnetic bonding with neighbors, and which holds the core robot assembly, including an inertial actuator and electronics. The inertial actuator is a reaction wheel with a fast acting band brake which is used to generate pulses of torque sufficient to induce lattice pivoting motions. Experiments characterizing the performance of the inertial actuator and the magnetic hinges are described. Additionally, experiments validating individual lattice movements demonstrate the feasibility of this approach to general 3D reconfiguration. Experiments describing modules modules individually and as groups are also presented.