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.

相位测量偏转法是一种高灵敏度的二维光学测量方法，可以非常准确地确定反射表面的细节，它可以定量测量被表面反射的参考结构（通常由计算机显示器表示）的变形。畸变测量得到的测量量是物体表面每个点的斜率，通过对数据进行微分，可以获得局部表面曲率，并且该方法对局部扰动的非常高的灵敏度导致了。的高度分辨率因此，这种方法已经应用于工业质量检测，以确定绝对物体形状，而相机和系统的各种校准方法是迄今为止最困难的任务。虽然几何形状已经成功建模和测试，但人们对真实显示器对参考图案的偏差知之甚少，而在迄今为止的所有分析中，大型显示器都被认为是理想的，并且也不能再将其视为平面。位于前面的散射屏迄今为止，发光像素和观察角度对强度的影响都尚未得到系统研究。拟议项目的目标是研究显示器的充分表征，包括相机和测量系统校准，以减少测量不确定性使用监视器的基于偏转测量的测量系统从目前在平坦或浅弯曲表面上的约 4 至 15 µm 提高约一个数量级到小于 0.5 µm，即使对于更强的弯曲表面也是如此在该项目中，以下子目标。有要实现的目标： i) 显示器的表征和描述真实显示器行为的模型的开发 ii) 将显示模型集成到相机的视觉光线校准中 iii) 包括显示模型和视觉光线的新型系统校准。稳定和不稳定表面测量程序的校准 iv) 基于经验的结果，通过使用平面和弯曲测试样品进行资格测量来系统地描述测量程序的偏差 v) 比较不考虑和考虑的结果，减少测量不确定性的实验证据。的属性真实显示器和改进的系统校准。该项目是由两个申请人合作设计的。在项目的第一部分，IPROM 研究了真实显示器行为的影响，而 BIAS 则制定并实验验证了测量系统校准的扩展方法。在项目结束时，将实现基于偏转测量的系统。