Laser-radar-based three-dimensional sensor for teaching robot paths

Abstract

Implementation and test results of a 3-D sensor based on time-of-flight (TOF) laser radar are presented. A sensor capable of measuring 3-D positions and orientations in a large working space is used for interactive teaching of robot paths and environments. It consists of a pointing device, a laser rangefinder, and a video tracker. The 3-D position and orientation of the pointer are obtained by measuring the distance from two separate points on the pointer arm to a tracking receiver and by using the tracking-camera image for detecting the angle of the pointer on the plane that is perpendicular to the optical axis of the tracking system. The rangefinder uses a new active target operating principle, including fiber-coupled transmitters attached to the pointer arm. The distance and angle measurement accuracies were measured to be better than ± 5 mm and ± 5 deg in the ranges of 2.3 to 4.7 &mum and ± 40 deg, respectively, using ordinary technology. The operating range is likely to be increased and the accuracy enhanced by using the latest state-of-the-art TOF rangefinding technique.