Network Representation and Design of Criterion Function for Assembly/Disassembly Task Planning

The automatic generation of assembly or disassembly sequences is needed to realize assembly or disassembly tasks with a robot. This problem can be deviled into the following three stages. They are, 1. modelling or representation of the assembly or disassembly network, 2. searching method, 3. decision of the criterion function. In earlier researches, what seems to be lacking in the problem 1 or 2 is a consideration of the task environment. Also, as for the problem 3, little attention has been given to it.In this paper, we propose a new assembly or disassembly sequence planning method. Firstly, we introduce a new assembly network representation with Petri Net graph which includes the environment in the conventional AND/OR graph. Secondly, we propose three criterion functions reflecting stability, manipulability and energy. These criterions fit well with experiences of a human operator. Also, we use the multi-objective Linear Programing to search the best sequence. Finally, we show examples to verify the validity of the proposed planning method.