Kinematics analysis of morphing process in multi-module robot systems

The multi-module robot systems consist of a set of homogeneous modules. In the paper, seven connecting types of cuboid modules are analyzed. For deriving the transformation matrix of each connecting type, the concepts of basic group are proposed. Then, the geometric relationships of each connecting type are derived with the group theory. With the rotary motion around the neighboring module, the morphing process from a quadruped to two-leg modular robot is shown. For the automatic generation of the kinematics of each modular robot, an approach has been adopted by a series of elemental matrixes multiplication with product of matrix exponentials. Examples of the kinematics on a quadruped and a two-leg modular robot are given to demonstrate the applicability of the proposed methods generating kinematics.