体视2D-3cPIV相机标定方法研究

基于针孔相机成像模型,利用共线方程建立了像平面坐标与粒子三维空间坐标之间的映射关系,在此基础上采用Tsai’s算法开展了相机内外参数标定方法的研究。使用微位移机构负载二维平面标定板完成了片光厚度内多个位置的单视场非共面标定。改进后的Wong-Trinder算子提高了标定板上目标像中心的定位精度。利用标准图像对其进行了仿真实验。结果表明,该标定方法具有标定速度快、精度高的特点,适合于多种流场的2D-3cPIV测量。

Study on method of camera calibration of stereoscopic 2D-3cPIV technique

According to the geometrical collinear equation founded on the pinhole camera model.The mapping relation between the image plane and three-dimensional real space is constructed.Furthermore Tsai's algorithm is utilized to obtain the intrinsic and extrinsic parameters of the camera.Driven by the tiny displacement machine,the two-dimensional calibration plate translates in the out-of-plane direction and their images at several locations in light sheet thickness are recorded so that monoview non-coplanar calibration procedure could be successfully completed.Moreover Wong-Trinder operator is improved to obtain higher subpixel precision of the target marker centers on image plane.The experimental result of the synthetic image proved the calibration method to be accurate and rapid and is suited for 2D-3cPIV measurement of varied flow fields.