Research On PowerCube Reconfigurable Modular Robots

Reconfigurable Modular Robots are of high-flexibility, consisting of a series of modular joints and links of various sizes and types. New configurations, based on new special tasks, can be established by interchanging and re-arranging of the modular joints and links. By means of reconfigurable robotic technology, mechanical systems can be reconstructed, and control systems can also work independently. In modern industrial applications and scientific experiments, the tasks are no longer fixed, so we need for a number of different configurations of robots.Using Reconfigurable Modular Robots can greatly reduce the costs and improve the efficiency.In this paper, we conducted a preliminary study on the PowerCube reconfigurable modules by a German company Amtec. Then by using one PowerCube wrist module, two PowerCube rotating modules, and some auxiliary modules, we have designed two different configurations of four-DOF robots in order to complete the space and plane task respectively.It is one of the main tasks to establish the unification model of the kinematic analysis of Reconfigurable Modular Robots. The kinematic model contains forward kinematic model and inverse kinematic one. In this paper, a general method of attatching local coordinate frams is obtained according to the DH approach, and the 4×4 matrix motion equations of this robot are derived. The initial position of the robot as an example we do the calculation of the positive solution. The correctness of the equations can be verified to some extent by checking the results of the calculations in relation to the initial position.From the view of the engineering application, inverse kinematics may be more valuable, in that it is the base of robot motion planning. This paper presents the inverse motion equations of the PowerCube modular robots. A separation of the variables of unknown and know in the matrix equation is conducteded by moving the unknown to the left before gettig its solution. Repeating in this way, we can get all the variables in each joint. It is necessary to observe and analyze the configuration and find the independent equations due to the fact that not all equations are independent with each other.Finally, we studied on such technology as the control system of the PowerCube Modular Robots, the programming language, the electrical control interface, and the CAN bus as the communication between the modules and a PC. In addition, a brief study on DLL (dynamic link library) has been done and an analysis to an available program is also completed, forming a foundation for the future research.