Architecture of industrial close-range photogrammetric system with multi-functional coded targets

This paper describes an industrial close-range photogrammetric system that is being developed by the authors. We describe the system's architecture based on an iterative scheme, which allows using fast heuristic point matching algorithms with the follow-up result verification. We also describe the design of our multi-functional coded targets that allow using those algorithms. Besides, this design allows the exact and robust determination of cameras pose and orientation in low-light scenes. We propose to use these coded targets as the scale reference in some fields of application, thus eliminating the necessity to use high priced precision scale bar. We also propose a technique for calibration of the base points of coded targets that increases measurement accuracy. We estimated the accuracy of our proposed approach both by simulation modelling and by real experiment. The implementation of the proposed multi-functional coded targets can significantly reduce the system's price and increase its usability in several application fields.