Automated motion of the forerunner mobile manipulator over the tube sheets

This paper describes algorithm for the automated motion over the tube sheets of steam generators implemented in the Forerunner manipulator. Forerunner belongs to a group of lightweight mobile manipulators for eddy current testing and repair actions of heat exchangers, primarily vertical steam generators in nuclear power plants of PWR type. Its task is to move along the tube sheet and position different tools at the entrance of the desired pipe. In order to facilitate the manipulator navigation, the high level of autonomy is integrated in the system so that operator only selects a group of tubes to be tested while the algorithms for automated motion decompose the command on sequential series of moves that must be made. Searching for the optimal path among several thousand tubes represents a real challenge from the mathematical point of view. The robustness of the proposed algorithm can be summarized in the following statement: if there is a solution to make the manipulator positioning in a given group of tubes, the algorithm will find it.