车载移动式视觉跟踪与测量系统在实际应用中,快速便捷地进行视觉系统与场地坐标系的全局统一是关键技术。结合视觉系统与现场特点,阐述了系统标定原理,给出了视觉跟踪与测量系统相对于场地坐标系转换数学模型。该方法的基本思路是转台视轴分别指向场地坐标系内的两个控制点,根据两点对应的俯仰角、方位角及距离确定两坐标系的转换关系。仿真分析和实验结果表明:角度和距离精度分别达到0.03°和0.52%。该方法便捷、高效,对移动式视觉测量系统坐标系快速统一有实用价值。
Expeditious calibration of vision measurement system with field coordinate system is fundamental and crucial, especially for movable visual tracking and measurement system. The calibrating principle of coordinate transformation was elaborated based on their characteristic, and mathematical model of the algorithm was proposed to calibrate the visual measurement system with field coordinate system. Two control points that parallel the axis in field coordinate were used as target. The calibrating results were computed based on azimuth and pitch angle of the visual measurement system when the line-of-sight collimated the control points. Simulation analysis and real data experiment results show that the angle error is 0.03°, and length error is 0.52%. The proposed algorithm is practical, convenient and wieldy to movable vision measurement coordinate system expeditious calibration.