Conceptual consideration for the process integration of optical sensors

Abstract

In manufacturing monitoring and inspection is an essential task to maintain a high product quality. Therefore a variety of systems (e.g. tactile systems, acoustic systems, optical systems,...) is used. However there is still a lack in controlling the product quality near the production machine. For the selection and the design of an appropriate monitoring strategy the specification of the applied sensors is of crucial importance. Optical sensors are in general suitable to measure quality relevant features. But they are often not robust enough, to use them in harsh environments such as the workshop floor. However to detect as early as possible if quality runs out off specification, the high resolution of optical measurement systems is often not needed. In these cases optical sensors can be implemented successfully even if their measurement uncertainty is increasing due to the harsh environment. To verify this hypothesis an evaluation of environmental influences has to be made and a comparison between the acceptable and still achieveable measurement uncertainty has to be made. For this reason a conceptual consideration regarding optical sensors developed for in-process monitoring is presented. The focus will be on the investigation of the influence of the environment on the measurement result, and on strategies how these can be estimated. Based on this an appropriate design and construction of the sensor system can be obtained.