The Kinematics Analysis of a Novel Self-Reconfigurable Modular Robot Based on Screw Theory

This paper introduces our newly designed self-reconfigurable modular robot named Larva-Bot, which has two DOFs with intersecting rotation axis normal to each other. Each module has autonomous mobility, and can assemble with other modules to form various configurations. In this study, a typical 6-DOF structure, composed of Larva-Bots, is proposed to analyze the kinematic characteristics of the modular robot. The common kinematics model of the robot is based on the Denavit-Hartenberg (D-H) parameter method, while its inverse kinematics has inefficient calculation and complicated solutions. To solve the problems, the screw theory method is applied in this paper. The forward kinematics model is constructed by using the product of exponentials (POEs) formula, while the inverse kinematics analysis is based on Paden-Kahan Sub-problems. Finally, the reliability of the method has been proved by computations and simulation.