Structure design and motion analysis of a modular robot with minimal vibration.

In this paper, a serial reconfigurable modular robot is presented. Each module is a cubic structure. Each surface of this cube has a connection interface. It has three rotational degrees of freedom, which are distributed along the three directions of its local coordinate system. A new and reliable docking mechanism is designed to realize the connection among adjacent modules. With the novel structure, the vibration of the modular robot is negligible. Then, based on the characteristics of the module, an eigenvector to describe the state information of a single module and an adjacency matrix to express the topology structure of a multi-module system are defined. Based on the screw theory, a kinematic model of the serial modular robot is proposed. Using an exponential product formula, the modular expressions of the kinematic equations are obtained automatically. According to the motion characteristics of each module and the structure characteristics of the modular robot, we can simplify the module which provides redundant degrees of freedom to a connecting rod. This method can reduce the complexity of solving the inverse kinematic solution. To solve the inverse kinematics automatically, we decompose it into two sub-motion models and propose the conditions of applying the subproblem method. Finally, a simulation by MATLAB is used to verify the correctness of the automatic generation of the forward and inverse kinematics. [ABSTRACT FROM AUTHOR]