Abstract
An offset compensation method using reflection-type photoelectric switches is studied with the aim of achieving a low-cost and highly accurate positioning control system. This system uses an open-loop control type robotic mechanism consisting of pulse motors and ball screws to reduce the cost. To make an optical connection in an automated optical cross-connect switching system, the robot must position optical fiber plugs at desired positions. The “on” region of the photoelectric switches is determined by scanning the plug grasped by the robot hand in front of the photoelectric switches. Offset compensation is achieved by calculating the difference between the initial position of the center of the region and the newly measured value. Experimental results show that the repetition error of the offset detection is less than 5μm (about 0.1% of the control position pitch) and the position variation of the center of the “on” region is less than 30μm when the distance between the switch and the plug is 0.1-1.0mm. The feasibility of this compensation method using photoelectric switches was confirmed by installing it into the automated optical cross-connect switching system.
