Academic Journals Database
Disseminating quality controlled scientific knowledge

Experimental validation of a 3-D vision-based measurement system applied to robot calibration

Author(s): Motta J. M. S. T. | McMaster R. S.

Journal: Journal of the Brazilian Society of Mechanical Sciences
ISSN 0100-7386

Volume: 24;
Issue: 3;
Start page: 220;
Date: 2002;
Original page

Keywords: Robot calibration | 3-D machine vision | absolute accuracy | camera calibration | robotic measurement systems

One of the problems that slows the development of off-line programming is the low static and dynamic positioning accuracy of robots. Robot calibration improves the positioning accuracy and can also be used as a diagnostic tool in robot production and maintenance. A large number of robot measurement systems are now available commercially. Yet, there is a dearth of systems that are portable, accurate and low cost. In this work a measurement system that can fill this gap in local calibration is presented. The measurement system consists of a single CCD camera mounted on the robot tool flange with a wide angle lens, and uses space resection models to measure the end-effector pose relative to a world coordinate system, considering radial distortions. Scale factors and image center are obtained with innovative techniques, making use of a multiview approach. The target plate consists of a grid of white dots impressed on a black photographic paper, and mounted on the sides of a 90-degree angle plate. Results show that the achieved average accuracy varies from 0.2mm to 0.4mm, at distances from the target from 600mm to 1000mm respectively, with different camera orientations.
Affiliate Program      Why do you need a reservation system?