A global calibration method for large-scale multi-sensor visual measurement systems

Each sensor in a multi-sensor visual measurement system has its own local coordinate system to which its measurements are referred. To use the measurement results, the data need to be transformed into a global coordination system. This indicates that all of the local sensor systems relative to the global coordinate system need to be calibrated by a global calibration method. In this paper, a method for calibrating the coordinate systems of a large-scale multi-sensor visual measurement system is introduced. The method utilizes a theodolite coordinate measurement system based on a theodolite pair to realize the global calibration. During the global calibration process, the theodolite coordinate measurement system measures the 3D coordinates of the feature points within each visual sensor relative to a global coordinate system. Then the global calibration can be implemented by means of direct and indirect transformation methods depending on the calibration targets. The calibration method has been successfully applied in practical applications. (C) 2004 Elsevier B.V. All rights reserved.