道路交通事故摄影测量定焦距内外参数分步标定模型

The Model Which Interior Parameters and Exterior Parameters Calibrated Separately for Photogrammetry of Traffic Accident Scene Using Fixed Focus Camera

为了获得稳定准确的三维信息,在道路交通事故现场摄影测量等应用中,采用固定焦距的普通非量测数码相机,在实验室条件下,采用二维平面标靶对数码相机的内部参数进行高精度预标定,照相机的外部参数利用预制标定点,采用现场在线标定的方法获得。该方法可减少现场在线标定过程中待辨识参数的数量,提高内外参数标定精度,并降低对现场标定点空间分布的要求。试验表明,采用内外参数分步标定技术,在10 m范围内,摄影测量误差小于1%,能够满足道路交通事故现场勘测要求。

In order to obtain the accurate and robust three-dimensions information, the fixed focus camera was used to measure the traffic accident scene. Interior parameters of fixed focus camera were calibrated accurately before the camera was used to do photogrammetry in laboratory, and coplanar points were used to calibrate interior parameters. The reference points were set on scene, and the exterior parameters were calibrated rapidly using them. For general camera, the number of parameters which must be calibrated is not less than 10. For the model which interior parameters and exterior parameters calibrated separately, the number of parameters which calibrated on scene is only 6.The precisions of estimated camera parameters were improved, and the requirement for distribution of reference points was lowered. The result of the test shows that the measurement error of the presented method is less than 1% for 10 m distance. It can be used to measure traffic accident scene rapidly and accurately.