Optical 3D motion measurement

This paper presents a CCD-camera based system for high-speed and accurate measurement of the three-dimensional movement of reflective targets. These targets are attached to the moving object under study. The system has been developed at TU Delft and consists of specialized hardware for real-time multi-camera image processing at 100 frames/s and software for data acquisition, 3D reconstruction and target tracking. An easy-to-use and flexible but accurate calibration method is employed to calibrate the camera setup. Applications of the system are found in a wide variety of areas; biomechanical motion analysis for research, rehabilitation, sports and ergonomics, motion capture for computer animation and virtual reality, and motion analysis of technical constructions like wind turbines. After a more detailed discussion of the image processing aspects of the system the paper will focus on image modeling and parameter estimation for the purpose of camera calibration and 3D reconstruction. A new calibration method that has recently been developed specifically for the measurement of wind turbine blade movements is. Test measurements show that with a proper calibration of the system a precision of 1:3000 relative to the field of view dimensions can be achieved. Future developments will further improve this result