Non-Contact Measurements for Industrial Quality Control

提出的研究旨在开发改进的方法非接触测试和质量控制的工业产品和过程。这些技术很有吸引力，因为它们对生产流程的影响最小。它们可以提供实时信息，并允许对材料质量和过程控制进行快速决策。为了给出一个具体的重点，我从木材工业中非接触测试的两种应用的角度制定了我的研究计划，但实际应用远远超出了这个范围。拟议的工作扩展和建立在以前对木材工业中用于材料质量控制的非接触式光学和x射线传感器的发展研究的基础上。******木材颗粒角度测量***为了在国际市场上有效竞争，加拿大锯木厂必须用可用的原材料生产出最高价值的产品。对于建筑产品，木材强度是主要关注的焦点。然而，木材的巨大可变性对强度评估提出了严重的挑战，因此质量控制变得非常保守。这种方法虽然安全性好，但严重浪费了大量高价值材料。******木材的强度直接取决于纹理方向。大约15度的偏差会使木材的强度减半。因此，颗粒角度是一个非常有效的木材强度指标。现有的测量方法只能测量表面（面内）颗粒角，而不能测量下潜（面外）颗粒角，存在一定的局限性。这里探索的定向反射方法的独特之处在于它可以测量两个角度。该方法利用木材表面的特性，在垂直于纹理的平面上优先反射入射光。在提出的工作中，探索了一种新型几何形状的测量装置，以使晶粒角轮廓扫描能够在大范围的晶粒角上进行。******工业锯片张力测量***在锯木厂，木材原料消耗约75%的总成本。因此，非常重要的是，工业锯应该尽可能薄，以产生最少的锯末废料，同时也要足够厚，以在一条直线上切割。允许的锯片厚度可以通过一种称为“张紧”的过程在锯体中施加应力来进一步减小。为了确定有效的加工条件，有必要单独评估每条锯。这种评估包括观察非常小的形状变化，这些变化很难以一致的方式测量。本文提出了一种测量锯片微小变形的方法——电子散斑干涉法（ESPI）。剪切成像ESPI技术特别适合，因为它测量地表斜率，因此可以更好地检测局部变形细节。********

The proposed research aims to develop improved methods for non-contact testing and quality control of industrial products and processes. Such techniques are attractive because they minimally impact production flow. They can give real-time information and allow prompt decision making for material quality and process control. To give a specific focus, I have framed my research program from the perspective of two applications of non-contact testing in the wood industry, but practical applications reach substantially beyond. The proposed work extends and builds on prior research on the development of non-contacting optical and X-ray sensors for material quality control in the wood industry.******LUMBER GRAIN ANGLE MEASUREMENT***To compete effectively in the international market, Canadian sawmills must produce the highest value products from the available raw material. For construction products, wood strength is a primary focus. However, the substantial variability of wood presents a serious challenge to strength assessments, so quality control becomes very conservative. While of good safety, this approach seriously wastes a lot of high value material.******The strength of wood depends directly on grain direction. A deviation of about 15 deg. halves wood strength. Consequently, grain angle is a very effective wood strength indicator. Established measurement methods are limited because they can measure only the surface (in-plane) grain angle, but not the diving (out-of-plane) angle. The directional reflection method explored here is unique in that it can measure both angles. The method exploits the characteristic of a wood surface to reflect incident light preferentially in a plane perpendicular to the grain. In the proposed work, a measurement device of novel geometry is explored to enable grain angle profile scans to be made over a wide range of grain angles.******INDUSTRIAL SAWBLADE TENSIONING MEASUREMENT***In sawmills, the wood raw material consumes about 75% of total costs. Thus, it is very important that industrial saws should be as thin as possible to produce minimum sawdust waste, while also being thick enough to cut in a straight line. The allowable sawblade thickness can be further reduced by inducing stresses into the saw body by a process called "tensioning". To determine effective processing conditions, it is necessary to assess each saw individually. This assessment involves observing very small shape changes that are difficult to measure in a consistent way. Electronic Speckle Pattern Interferometry (ESPI) is proposed here as a means of measuring the small deformations in sawblades. The shearographic ESPI technique is particularly well suited because it measures surface slope and so can better detect local deformation details.********