A simple laser-based distance measuring device

Abstract We report on a simple laser-based sensor for distance, velocity and shape measurements. The distance between the sensor and the measurement object is evaluated by a new triangulation principle. A laser beam providing a high spatial resolution is scanned across the measurement object. The triangulation angle is determined by means of a time difference measurement of reflected light focused on two different detectors. The measurement range covers several centimeters to some 10 m, the relative error of a single shot measurement is less than I I% and could be reduced by multiple shot measurements of less than 5%. The measurement repetition rate is up to 200 kHz depending on the emitted laser intensity and the evaluation circuit. Applications of the instrument in industry, quality control and traffic control are discussed.