Highly accurate deflectometric shape measurement including the non ideal properties of a display as reference plane

高精度偏转形状测量，包括作为参考平面的显示器的非理想特性

基本信息

批准号：
298137953
负责人：
Professor Dr. Ralf Bernhard Bergmann
金额：
--
依托单位：
BIAS - Bremer Institut für Angewandte Strahltechnik GmbH
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2015
资助国家：
德国
起止时间：
2014-12-31 至 2018-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/298137953?language=en
关键词：
Highly accurate deflectometric shape measurement

项目摘要

Phase-measuring deflectometry is a highly sensitive, 2-D optical measurement method that can determine details of reflective surfaces very accurately. It measures quantitatively the distortion of a reference structure (often represented by a computer monitor) that is reflected by the surface to be measured. The measured quantity resulting from the distortion measurement is the slope for each point of the object surface. By differentiating the data, the local surface curvature can be obtained, and the very high sensitivity of the method with regard to local disturbances leads to a height resolution on the order of one nanometre with little effort. Therefore, this method has found its way into industrial quality inspection. Integration of the slope data to determine the absolute object form is by far the harder task. While various methods for calibration of the camera and the system geometry have been modelled and tested successfully, very little is known about the deviations that a real display imparts to a reference pattern assumed to be ideal in all hitherto existing analyses. Large displays can no longer be regarded as planar surfaces, and neither the impact of the scattering screen located in front of the luminescent pixels nor the influence of the observation angle on the intensity have hitherto been systematically investigated.The goal of the proposed project is to do research on an adequate characterization of the display, including the camera and measurement system calibration in order to reduce the measurement uncertainty of measurement systems based on deflectometry using a monitor from currently around 4 to 15 µm at flat or shallow curved surfaces by around one order of magnitude to smaller than 0,5 µm even for stronger curved surfaces. Within the project, the following sub-goals have to be achieved: i) Characterization of displays and development of a model describing the behavior of real displays. ii) Integration of the display model in the vision ray calibration of the camera. iii) Novel system calibration including the display model and the vision ray calibration for procedures for the measurement of steady and unsteady surfaces. iv) Empirically based results to systematically describe deviations of the measurement procedure via qualification measurements using flat and curved test samples. v) Experimental evidence of reduced measurement uncertainty comparing results without and with consideration of the properties of real displays and improved system calibration.The project is designed as a cooperation of two applicants. During the first part of the project, IPROM investigates the influence of the behavior of real displays, while BIAS formulates and experimentally verifies extended approaches of system calibration for measurement systems based on deflectometry. Towards the end of the project, a joint measurement system will be realized.

相位测量演示是一种高度敏感的2D光学测量方法，可以非常准确地确定反射表面的细节。它定量测量参考结构的失真（通常由计算机监视器表示），该参考结构由要测量的表面反映。失真测量结果产生的测量数量是对象表面每个点的斜率。通过区分数据，可以获得局部表面曲率，并且该方法在局部灾害方面的灵敏度非常高，从而导致一个纳米计的高度分辨率在一个纳米计的顺序上，却很少。因此，这种方法已进入工业质量检查。到目前为止，确定绝对对象形式的斜率数据的集成是更艰巨的任务。尽管已经成功地建模和测试了相机校准和系统几何形状的各种方法，但对于迄今为止所有现有分析中的所有参考模式，真实的显示iMpparts to The Comeuction Impparts都对参考模式却是理想的，鲜为人知。大型显示器不再被视为平面表面，并且既不是在发光像素前面的散射屏幕的影响，也不是迄今已系统地研究观察角对强度的影响。该项目的目的是对显示器的适当表征进行研究，包括对摄像机和测量系统的适当表征，包括对摄像机和测量系统校准的表征，并进行研究。从目前在平坦或浅弯曲表面上的4到15 µm左右，即使对于更强的弯曲表面，甚至小于0.5 µm。在项目中，必须实现以下子目标：i）描述描述真实显示行为的模型的显示和开发。 ii）在摄像机的视觉射线校准中将显示模型集成。 iii）新型系统校准，包括显示模型和视觉射线校准，用于测量稳定和不稳定表面的过程。 iv）基于经验的结果通过使用扁平和弯曲的测试样品进行资格测量系统地描述测量程序的出发。 v）测量不确定性降低的实验证据比较结果，而没有并考虑实际显示的特性和改进的系统校准。该项目被设计为两种应用的协调。在项目的第一部分中，IPROM研究了真实显示行为的影响，而偏差则进行了制定和实验验证基于eNoThemetry的测量系统的系统校准的扩展方法。在项目结束时，将实现一个联合测量系统。