Abstract: To demonstrate the benefit of a reconfiguration mechanism with powerful driving force and large workspace to enhance the locomotion ability of mobile robot, a reconfigurable mobile robot based on serial and parallel mechanism is presented, and it is composed of three modules which can dock and disconnect with each other by docking mechanisms. Firstly, two screw and sliding mechanisms with high torque amplifying ratio are proposed to be the branches of a parallel mechanism. Then an active spherical joint mechanism is realized by serially connecting the parallel mechanism with a rotating mechanism whose axes are orthonormal with each other and intersect at one point. The serial and parallel mechanism is attractive in the characteristics of high output torque, large work space and small structure. Secondly, the kinemics converse formula of the mechanism is deduced to be the basis of motion control, and the static formula is also concluded to determine the drivable workspace under certain load. Furthermore, a docking mechanism being capable of compensating the position and direction error in plane is designed to realize the docking and disconnecting action between two modules. To testify the formulas and the availability of the mechanisms, a prototype named JL-1 is designed. Finally a series of successful on-site tests confirm the principles described above and the validity of the active spherical joint mechanism and the docking mechanism. The results show that the powerful reconfiguration abilities can obviously enhance the adaptability of mobile robot to rugged terrain.

Key words: Parallel mechanism, Reconfigurable robot, Serial mechanism, Spherical joint