Volume 22 Issue 10/11- Publication Date: 1 October 2003
Predictive Tracking of Lines by Industrial Robots
F. Lange and G. Hirzinger Institute of Robotics and Mechatronics, Deutsches Zentrum für Luft-und Raumfahrt (DLR), Oberpfaffenhofen, D-82234 Wessling, Germany

Many tasks for industrial robots can be described by high precision line following at high speed. This can be executed accurately if the lines are sensed by a camera since then not only the desired pose at the current time step is sensable, but also a segment of the desired path can be predicted. We propose polynomials to represent the progression of the elements of the desired pose. This allows us to realize a dynamical sensor control architecture that considers the two main problems: low sampling rate and delays in image processing, and deviations from commanded paths due to the robot dynamics. In contrast to previous publications we now present the complete formulae to control translation and orientation of the robot by tracking (curved) lines that are visible for a single eye-in-hand camera. Experiments using off-the-shelf hardware show that the robot can be precisely controlled at high speed.

Multimedia Key
= Video = Data = Code = Image
Example One: Robot motion along two sensed lines. (0.6MB)
Example Two: Camera view during motion along two sensed lines. (0.9MB)
Example Three: Robot motion along a single. (0.7MB)
Example Four: Camera view during motion along a single sensed line. (0.7MB)
Return to Contents