tailieunhanh - Advances in Theory and Applications of Stereo Vision Part 10

Tham khảo tài liệu 'advances in theory and applications of stereo vision part 10', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Address-Event based stereo Vision with Bio-inspired Silicon Retina Imagers 215 4. Quick calibration method for ultrasonic 3D tag system Measurement and calibration In the ultrasonic 3D tag system that the authors have developed calibration means calculation of receivers positions and measurement means calculation of transmitters positions as shown in Fig. 14. Essentially both problems are the same. As described in the previous section the robustness of the ultrasonic 3D tag system can be improved by increasing the number of ultrasonic receivers. However as the space where the receivers exist widens it becomes more difficult to calibrate receivers positions because a simple calibration method requires almost the same size of a calibration device which has multiple transmitters. This paper describes a calibration method which requires relatively small number of transmitters such as three or more and therefore doesn t require the same size of the calibration system as that of the space where the receivers exist. Fig. 14. Calibration and measurement Quick calibration method In the present paper we describes a global calibration based on local calibration GCLC method and two constraints that can be used in conjunction with the GCLC method. The procedure for GCLC is described below. 1. Move the calibration device arbitrarily to multiple positions A B and c in Fig. 15 . 2. Calculate the positions of the receivers in a local coordinate system with the local origin set at the position of the calibration system. The calculation method was described in the previous section. 3. Select receivers for which the positions can be calculated from more than two calibration system positions. 4. Select a global coordinate system from among the local coordinate systems and calculate the positions of the calibration device in the global coordinate system using the receivers selected in Step 3. Then calculate transformation matrices Ml and M2 in Fig. 15 . 5. Calculate the receiver