Method for vectorial robot movement determination enabling accuracy improvements

Abstract

Promising approaches for robot accuracy improvements belong to the visual servoing methods. These methods comprise closed-loop control systems, which utilize sensors to guide the robot relative to visible features of a workpiece. However, the known methods show limitations regarding their usability for highly accurate applications or tasks without a predetermined process pathway. To overcome this problem, at FAPS a system for high-speed monitoring of the work-piece's movement is investigated. The system enables a closed-loop control of the robots motion, if a deviation between actual and planned movement is determined. For the actual movement determination, a highly efficient and accurate image data processing system, based on a vectorial movement determination of fiducial markers is developed. In this context, a highly efficient and geometrical accurate actual state determination constitutes a significant challenge. Experiments show, that the system allows a position determination in an area of ten microns at a frequency faster than 500 Hz, thus enabling a reactive robot control and accuracy improvement. Keywords-visual servoing; image data processing; robot controlI.