Measurement of dimensions using robot constructed utilizing optical fiber signal transmission system having reference capability

This paper describes the optical signal transmission system constructed using direct intensity modulation technique which is capable of transmitting a signal through a movable optical fiber, and its application to the measurement of dimensions using a robot. This system simultaneously transmits the signal and reference lights from a transmitter to a receiver. At the receiver, the signal is normalized by the reference so as to provide the correct output signal. When the optical fiber was bent with a bending radius of 10 mm at a bending angle of 180 degrees, the transmission error was 0.28 in the conventional single-path system. Under the same bending conditions, the error was improved to 0.03 in the proposed system due to the reference capability. This system was experimentally applied to transmit data from the displacement sensor to the recorder when the displacement sensor was attached to the arm of the robot through the movable optical fiber installed in the arm of the robot. The proposed system can transmit an optical dimension signal with the minimum error through a movable optical fiber. The experiment was successful.