A Characteristics Measurement of Two-Dimensional Range Scanner and its Application

This paper shows the result of the characteristics measurement of a two-dimensional active range scanner, URG made by Hokuyo Automatic Co., Ltd. which was released in 2004 and is spreading widely as an external sensor for mobile robot. The following items were clarified from the characteristics measurement of URG-X002S in various conditions. (1) In the case that the object has a gloss surface or a black surface, the error rate (the frequency that the scanner judges to be impossible to measure and an error code is output) rises when the oblique angle of object becomes large and also the distance to object becomes long. (2) In the case that the object has a white surface or a rough surface, not only the error rate is zero but also the margin of error becomes dozens of millimeters and the varying is small, if the oblique angle is smaller than 60 deg and the distance is shorter than 1 m. (3) The lateral error is negligibly small if the distance to detect is shorter than 1 m. Moreover it shows the result of the examination to apply the range scanner in the Step-On Interface (SOI), in which the scanner is used for detection and measurement of the stepping of an operator. Based on the measured results, we designed the judgment method of the stepping, the installation position of the scanner, and the placement of buttons in the direction screen to apply the range scanner to the SOI for operation of a mobile robot.