Multi-sensor geometry measurement on large-scaled gears

新的尺寸测量系统对于满足不断提高的生产公差要求是必不可少的。大体积计量应用对测量系统动态范围的要求不断提高。以大型齿轮为例，公差随直径和模数的增加而增大，但所需的测量不确定度与测量体积之比减小。与直径有关，评估大型齿轮的总轮廓偏差所需的测量不确定度必须比小型齿轮的测量不确定度小一个数量级。此外，三坐标测量机和齿轮测量仪在测量大型齿轮时很快达到极限。它们是为串行数据采集而设计的，只提供有限的测量体积。因此，这些设备速度很慢，而且很难扩展。目前用于大体积计量的测量系统要么在一定程度上用于串行数据采集，要么不能提供所需的测量不确定度。该项目旨在解决大型物体尺寸测量的挑战，涉及测量系统的动态范围和可扩展性，以及后勤工作和测量时间。目的是通过将基于模型的方法与光学距离传感器的多传感器设置相结合，以大型齿轮为例，介绍一种用于大型物体尺寸测量的测量系统。由于其模块化结构，多传感器系统可以很容易地适应所需的测量体积。因此，它非常适合于测量大型物体或作为原位测量系统。利用快速传感器同时获取物体表面多个点的能力，减少了测量时间。本项目的重点在于基于模型的实际齿轮几何形状参数（基径）的评估和基于测量不确定度分析的多传感器系统的优化设计。因此，对于直径为2m的测量对象，形状参数的不确定度应达到< 5µm。单个距离传感器所需的动态范围也是研究的主题，因为测量范围的增加通常伴随着测量不确定性的增加。因此，是否可以在不增加测量不确定度的情况下，利用自适应光学元件快速跟踪测量区域的位置，是一个需要明确的问题。基于光学传感器的多传感器系统将在现有的大型三坐标测量机上进行验证。此外，将首次分析测量系统和基于模型的评估是否以及如何扩展到更复杂的几何形状。

New dimensional measuring systems are essential to keep pace with the raised requirements concerning production tolerances. The needed dynamic range of the measurement system is steadily increasing for applications of large volume metrology. For large-scaled gears, for instance, the tolerances increase with increasing diameter and module, but the ratio of needed measurement uncertainty and measuring volume decreases. Relating to the diameter, the required measurement uncertainty for assessing the total profile deviation of a large-scaled gear has to be one order of magnitude less than for a small gear. Furthermore, coordinate measuring machines and gear measuring instruments quickly reach their limits when measuring large-scaled gears. They are designed for a serial data acquisition and provide only a limited measuring volume. Thus, these devices are slow and hardly scalable. Current measuring systems for large volume metrology are either designed for serial data acquisition to some extent or do not provide the required measurement uncertainty.The intended project addresses the challenges of the dimensional measurement of large objects concerning the dynamic range and the scalability of the measuring system as well as the logistic effort and measurement time. The objective is to introduce a measuring system for the dimensional measurement of large objects using the example of large-scaled gears by combining a consequent model-based approach with a multi-sensor setup of optical distance sensors. Due to its modular architecture, the multi-sensor system can be easily adapted to the required measuring volume. Therefore, it is well suited for the measurement of large objects or as an in-situ measuring system. The capability of simultaneously acquiring multiple points on the object's surface by means of fast sensors reduces the measuring time.The focus of this project lies on the model-based evaluation of a form parameter of the actual gear geometry (base diameter) and on an optimal design of the multi-sensor system, based on a measurement uncertainty analysis. As a result, for a measuring object with a diameter of 2 m, an uncertainty of the form parameter < 5 µm should be reached. The required dynamic range of the individual distance sensors is also a subject of the research, as increasing the measuring range typically goes along with an increased measurement uncertainty. Thus, it should be clarified whether the location of the measuring zone could be quickly tracked with adaptive optic components without increasing the measurement uncertainty. The characterized multi-sensor system, which is based on optic sensors, will be validated by means of an existing large coordinate measuring machine. Moreover, it will be analyzed for the first time, whether and how both the measuring system and the model-based evaluation can be extended to more complex geometries.