Simulation and control of reconfigurable modular robot arm based on close-loop real-time feedback

Reconfigurable modular robot is a new aspect in the development of robotics. Compared with the traditional robots, a lot of attentions have been paid to the advantages of the reconfigurable modular robot, such as the variety of structure and the adaptability to the complicated environment. At present, most robotic control methods only use the feedback of motor encoder, not use the feedback of actual end-position of robot arm. However, due to the joint flexibility and integral assembly error, the control accuracy of robot arm is not high only according to the motor feedback. Therefore, this control method is the open-loop approach. In this study, a PowerCube reconfigurable modular robot system is presented with motion simulation and control of close-loop real-time feedback using Optotrak3020 measurement system. The mechanical and electrical layout of PowerCube module robot, the robot motion model, the control concept and implementation of close-loop real-time feedback are investigated respectively. Finally, through a 3D simulation and experiment of modular robot arm for grasping a cup and pumping water, the feasibility and applicability of this control strategy are verified.