Based on optical triangulation principle,3D sensor based on structure-light has many special characteristics such as non-contact, high efficiency, good precision, which enable it is widely applied in the field of 3D digitization technique. In 3D digitization system, the mapping relationship between real-world 3D information and computer virtual world information is derived by calibration. Calibration technique is the most important technique of 3D digitization technique.
Based on the detailed analysis of present research status, study has been carried out on calibration technique of 3D sensor and mathematical model of 3D sensor based on structure-light is presented in detail. Then, the calibration work of foot 3D scanner is carried out with the “two step” method. Finally the foot scanning system is embedded with the calibrated results, and the scanning experiment on the standard metal gauge is performed to verify the correctness of the calibration theory by analyzing the measuring precision.
The main study and innovation are as follows:
1、The foot 3D scanner is improved by designing and manufacturing the electric control cabinet.
2、The foot 3D scanner is calibrated through two process. First, the detecting algorithm and the sorting algorithm of the corner point of black-white chessboard are improved, then the intrinsic parameters and lens distortion co-efficiency of the camera are solved by Zhang's camera calibration method. Basing on these, the real image coordinate is corrected. Then the linear transformation relation between the ideal image coordinate and the global coordinate is set up by a filament calibration target.
3、The new calibrated parameter is embedded in the system, and the scanning experiment on standard metal gauge is performed. The correctness of the calibration theory is verified by analyzing the measuring precision.
Key words: Linear structure-light; 3D sensor model; Calibration target; Calibration technology
Based on optical triangulation principle,3D sensor based on structure-light has many special characteristics such as non-contact, high efficiency, good precision, which enable it is widely applied in the field of 3D digitization technique. In 3D digitization system, the mapping relationship between real-world 3D information and computer virtual world information is derived by calibration. Calibration technique is the most important technique of 3D digitization technique.
Based on the detailed analysis of present research status, study has been carried out on calibration technique of 3D sensor and mathematical model of 3D sensor based on structure-light is presented in detail. Then, the calibration work of foot 3D scanner is carried out with the “two step” method. Finally the foot scanning system is embedded with the calibrated results, and the scanning experiment on the standard metal gauge is performed to verify the correctness of the calibration theory by analyzing the measuring precision.
The main study and innovation are as follows:
1、The foot 3D scanner is improved by designing and manufacturing the electric control cabinet.
2、The foot 3D scanner is calibrated through two process. First, the detecting algorithm and the sorting algorithm of the corner point of black-white chessboard are improved, then the intrinsic parameters and lens distortion co-efficiency of the camera are solved by Zhang's camera calibration method. Basing on these, the real image coordinate is corrected. Then the linear transformation relation between the ideal image coordinate and the global coordinate is set up by a filament calibration target.
3、The new calibrated parameter is embedded in the system, and the scanning experiment on standard metal gauge is performed. The correctness of the calibration theory is verified by analyzing the measuring precision.
Key words: Linear structure-light; 3D sensor model; Calibration target; Calibration technology