Motion switching control of robotic manipulators and reducing a throughput time in handling semiconductor wafers

This paper considers control design problems for a robotic manipulator that is used for handling silicon semiconductor wafers, and how to reduce the throughput time of the total task of the manipulator. In this paper, we propose discontinuous switchings of controllers which are already designed and realize appropriate motions for each translatory and rotational motions. We show that such a controller switching algorithm can be derived by utilizing an invariant set of the rotating motion dynamics of the manipulator. Effectiveness of our proposed algorithm is evaluated through experiment of the wafer transfer robot.