For a self-reconfigurable robot, how to metamorphose to adapt itself to environment is a difficult problem. To solve this problem, a new relative orientation model which describes modules and their surrounding grids was given, a module motion rules database which enables the robot to avoid obstacles was established, and finally a three-layer planner based on dynamic meta-modules was developed. The firstlayer planner designates the category of each module in robot by evaluation functions and picks out the modules in dynamic meta-modules. The second-layer planner plans the dynamic meta-module path according to output parameters of the first-layer planner. The third-layer planner plans the motion of the modules in dynamic meta-module using topology variation oriented methods. To validate the efficiency of the three-layer planner, two simulations were given. One is the simulation of a single dynamic meta-module, the other is the simulation of planning with an initial configuration composed of 8 modules in complicated environment. Results show that the methods can make robot with any initial configuration move through metamorphosis in complicated environment efficiently.
Configuration information acquisition and matching are two important steps in the self-reconfiguring process of self-reconfigurable robots. The process of configuration information acquisition was introduced, and a self-reconfiguring configuration matching strategy based on graded optimization mechanism was proposed. The first-grade optimization was to search common connection between matching scheme and goal configuration. The second-grade optimization, whose object function was constructed in terms of configuration connectivity, was to search connnon topology according to the results of the first-grade optimization. The entire process of configuration information acquisition and matching was verified by an experiment and genetic algorithm （GA）. The result shows the accuracy of the configuration information acquisition and the effectiveness of the configuration matching method.
