排序方式: 共有15条查询结果,搜索用时 16 毫秒
1.
为了提高条纹投影三维(3D)测量系统的测量速度和准确度,提出了一种改进的相位高度转换映射模型。通过建立虚拟相机坐标系以及分析条纹信息在投射器坐标系与相机坐标系之间的转换关系,在相机坐标系中建立了从相位到高度的一一映射模型,并在映射模型中校正了相机镜头的畸变。该模型结构简单,便于结合查表(LUT)法使用。应用查表法后,模型算法复杂度极低,可以应用在高速测量中。同时,提出了一种针对映射模型的标定方法,并在相机标定过程中利用逆向投影优化过程对相机的参数进行迭代优化。标定方法简单高效,不需要参考平面,且对系统中的相机和投射器的相对位姿没有严格的要求。实验结果表明所提映射模型及标定方法可以实现快速准确的三维测量。 相似文献
2.
3.
A two-step method for pose estimation based on five co-planar reference points is studied.In the first step, the pose of the object is estimated by a simple analytical solving process.The pixel coordinates of reference points on the image plane are extracted through image processing.Then,using affine invariants of the reference points with certain distances between each other,the coordinates of reference points in the camera coordinate system are solved.In the second step,the results obtained in the first step are used as initial values of an iterative solving process for gathering the exact solution.In such a solution,an unconstrained nonlinear optimization objective function is established through the objective functions produced by the depth estimation and the co-planarity of the five reference points to ensure the accuracy and convergence rate of the non-linear algorithm.The Levenberg-Marquardt optimization method is utilized to refine the initial values.The coordinates of the reference points in the camera coordinate system are obtained and transformed into the pose of the object.Experimental results show that the RMS of the azimuth angle reaches 0.076°in the measurement range of 0°-90°;the root mean square(RMS) of the pitch angle reaches 0.035°in the measurement range of 0°-60°:and the RMS of the roll angle reaches 0.036°in the measurement range of 0°-60°. 相似文献
4.
SO2 monitoring in the flue gas of a coal burning boiler is important for environmental protection. The non- linearity of practical condition causes deviation from theoretical law. On the basis of the Lambert-Beer Law, a new four-step calibrntion method is introduced. This method includes cross section interpola- tion, weighting spectral region combination, acquiring the spectrum with new calibration devices, and least-square fitting. Compared with conventional methods, this new method is low cost, convenient, and accurate. In the proof test, SO2 samples with different concentrations are measured. The average errors are less than 1.5%, while the maximum deviation is less than 4.5%. 相似文献
5.
A 3D acquisition system combination of structured-light scanning and shape from silhouette 总被引:1,自引:0,他引:1
A robust and accurate three dimensional (3D) acquisition system is presented, which is a combination of structured-light scanning and shape from silhouette. Using common world coordinate system, two groups of point data can be integrated into the final complete 3D model without any integration and registration algorithm. The mathematics model of structured-light scanning is described in detail, and the shape from silhouette algorithm is introduced as well. The complete 3D model of a cup with a handle is obtained successfully by the proposed technique. At last the measurement on a ball bearing is performed, with the measurement precision better than 0.15 mm. 相似文献
6.
设计了一种高速扫描频闪激光光栅条纹实时投射系统。系统通过现场可编程门阵列(FPGA)实时监测光电探测器信号并控制激光器的调制输出,使高速旋转的多面棱镜与线激光器调制信号精确配合产生稳定、清晰、精密的频闪激光光栅条纹。系统结合了光栅条纹整体投射和线激光光源高精度的特性,具有刷新速度快、条纹分布精度高的特点,且亮度、频率、脉宽、相移可动态编程实时控制。应用该系统对微小尺寸器件进行了测量,获得了准确反映被测器件三维形貌的相位和特征点数据。该系统在高精度快速三维形貌测量中,尤其是工业现场精密器件在线三维检测场合具有广泛的应用前景。 相似文献
7.
The pose estimation method based on geometric constraints is studied.The coordinates of the five feature points in the camera coordinate system are calculated to obtain the pose of an object on the basis of the geometric constraints formed by the connective lines of the feature points and the coordinates of the feature points on the CCD image plane;during the solution process,the scaling and orthography projection model is used to approximate the perspective projection model.The initial values of the coordinates of the five feature points in the camera coordinate system are obtained to ensure the accuracy and convergence rate of the non-linear algorithm.In accordance with the perspective projection characteristics of the circular feature landmarks,we propose an approach that enables the iterative acquisition of accurate target poses through the correction of the perspective projection coordinates of the circular feature landmark centers.Experimental results show that the translation positioning accuracy reaches ±0.05 mm in the measurement range of 0-40 mm,and the rotation positioning accuracy reaches ±0.06° in the measurement range of 4°-60°. 相似文献
8.
9.
10.
In order to estimate the position and orientation of an object with a single camera, a novel measurement method based on pinhole camera model with five reference points is presented. Taking the specially designed planar target with the monocular vision system, the projection line of the reference points is built. According to the projection model, the coordinates of the reference points in the camera coordinate system are estimated with the least-squares algorithm. Thus the position and orientation of the target are worked out. Experimental result shows that the measurement precision of angle is less than 0.2°, and that of displacement is less than 0.1 mm. 相似文献