Abstract: The present invention is a distance measuring device having a low power laser for use outdoors. The distance measuring device of the invention includes a laser emitting means that emits a pulsed laser beam to an object to be measured and an image reader that takes in irradiations images and stop period images of the object synchronously with an irradiation and stop period of the laser beam. A processing device then subtracts the stop image pixel values from the emission image pixel values to produce differential images. A minimum value image of the differential images is processed and binarized using a binary threshold to produce binary data from which a position where the laser beam is received is found. A calculation apparatus then determines a distance between the laser beam receiving position and the object based on the position where the laser beam is received.

Abstract: A method of detecting and controlling a work start point of a robot of the teaching playback control type is disclosed. The robot has an interpolating function and responds to a position sensor, and a work tool is attached to the robot wrist to be accurately positioned to a work start point of a work object. A shadow of the work tool is produced by an illumination source. The work line of the object, the work tool, and the shadow thereof are image-recognized by a visual sensor. The visual sensor generates position correcting signals along the first and second correcting directions on the basis of the image recognized. The edge of the work tool is moved along the first correcting direction in response to a position correcting signal so as to reduce the distance between the work line and an edge of the work tool on the image recognized.