Robot Pose Correction using Photogrammetric Tracking

摘要

Traditionally, one of the driving forces behind the development of industry robots was the goal to replace tedious or hazardous manual work such as welding or varnishing. However, as robot prices are falling cosntantly, the use of robots becomes an economically sound solution in more and more applications - including areas which have nothing in common with the traditional "harsh environment" scenario. with the wider application scope, there also come more and tighter requirements, one of them certainly being accuracy. The accuracy of a robot can be asserted by measuring the position and orientation of its end effector. For this purpose there exist a number of techniques, one of them being photogrammetric measurement. Robot manufacturers have used photogrammetry since several years in order to carry out a factory calibration. HOwever, there is a growing need for systems which are able to calibrate and constantly monitor a robot on the factory floor. This paper describes the possibilities which are offered by recent developments in sensors, image processing and close range photogrammetry. It then shows first results towards an on-line photogrammetric robot tracking system which have been obtained by a research group at the University of Stuttgart, Germany.