Fringe projection profilometry using rigid and flexible endoscopes

Abstract

Abstract Quality control is an important aspect of modern production processes. Obtaining quantitative information not only helps to ensure the function of machinery and products, but also enables cost reduction by feedback control of process parameters. A multitude of modern industrial applications feature an increasing amount of highly integrated machinery, resulting in a requirement for new measuring devices. Two new measuring systems are presented for in-situ inspection tasks in confined spaces. A combination of endoscopy techniques with structured illumination enables capturing areal 3-D geometry information of functional elements in integrated machinery. Depending on the requirements for inspection, either rigid or flexible image guides may be used to transport the structured light patterns. While a flexible endoscope allows for a more flexible positioning of the sensor head, its resolution is limited by the number of individual fiber cores. Alternatively, if constraints on the versatility of sensor positioning can be accepted, rigid endoscopes feature higher image quality. Both approaches are described in detail and compared based on evaluations on features of a calibrated micro contour standard.