Hardware Design

ModRED is a homogeneous modular robot system based on 4 per module degree-of-freedom (DOF), including a prismatic DOF to increase the versatility to its reconfiguration and locomotion capabilities. The ModRED modules are developed with mechanically latched docking interfaces that allow chain configuration and leading toward hybrid configuration with the proposed RoGenSiD (Rotaryplate Genderless Single-sided Docking) connector mechanism allowing multifaceted docking of the modules.

Each of the ModRED modules has 4 DOF - 3 rotational and 1 prismatic. The module has five distinct segments i.e., two end brackets containing the docking interfaces and three box-shaped segments housing the actuators, transmission, circuit components and power source. The docking brackets have a rotation range of ±90°. Relative to the central box segment, one end segment has an infinite angle of twist whereas the other end box segment has a 0-1 inch linear range of displacement. A module is capable of producing pitch, yaw, and roll and one extension DOF.










Simulation and implementation of locomotion gaits

In this work various locomotion gaits are simulated through Webots software and implemented in the real ModRED system to achieve gait table-based locomotion tasks. Simulation of the system is essential to fully understand and refine its kinematics. We can accurately control forces with which each part’s action is effected so that the desired motion is obtained.



Self-reconfiguration problem

One of the principal computational challenges in MSRs is to solve the self-reconfiguration problem, i.e., how to adapt their shape autonomously so that they can change tasks or continue their operation after encountering obstacles or occlusions that impede their movement. We model the self-reconfiguration problem as an instance of the graph-based coalition formation problem. We formulate the problem as linear program that finds the 'best' partition or coalition structure among a set of ModRED modules.