Abstract:   This paper discussed the problem of planar docking between two modules of an underwater self-reconfigurable robot(USR). From the relation between the sensors intensity and coordinate errors of the modules, the optimized function ofthe docking problem was presented. Due to the fact that the module-s kinematics is invertible, the docking problem wasseparated into three sub-optimized problems in the directions of x, y and θ respectively. Based on the concept of centering method, the sub-optimized functions in the threedirections were presented, and the docking controllers in these directions were designed. The discrete model of themodule-s inverse kinematics was derived. To increase the precision of computation, a stabilizing discrete scheme wasproposed. The simulation results illustrate and validate the effectiveness of the proposed docking control method.  

Key words: underwater self-reconfigurable robot (USR), docking control, inverse kinematics, centering method