We have been developing a teleoperation type robotic system for hot line maintenance. In the system, a dualarm robot is operated by manual control and automatic control. The range information of objects is very useful for the automatic operation. We have developed a range sensor system in which a range sensor measures the distances to an object and the robot manipulates the object based on the range data. This paper describes the range sensor system. The range sensor consists of a spot laser source and two CCD cameras, and computes ranges using triangulation method. In order to reduce the influence of sunlight, the laser emission synchronizes with the frame signal of the camera. A differential images are obtained by subtraction of two sequential raw images and a minimum image is computed from the differential images. The laser spot on an object is detected in the minimum image. Calibration is essential for a sensor-based robot. This paper also mentions the calibration method, and lastly the application examples for robot manipulation and robot base approach are presented.
