Optical Sensor Setup for Robust Quality Control Measurements On Large Cylindrical Structures

摘要

In the present paper we describe a measurement setup to perform quality control measurements on a rotationally symmetric object. The focus of this setup is on the offset and tilt between the top and bottom lids as these parameters are critical for the final application of the device under test. The achieved accuracy of the system is 0.01 mm (3σ) for displacements and tilt. The proposed system utilises the Discrete Fourier Transform to estimate the unknown parameters of the cylinder based on relative distances measured by two optical 2D range sensors. This approach abandons the need for accurate references which would drastically increase the costs of the system as the inspected cylinders are large compared to the required accuracy. Furthermore, the application of optical sensors allows to perform the quality control measurements accompanying the manufacturing process without interference. The setup imposes only weak limitations on the accuracy of the sensor positioning and imperfections of the manufacturing setup which has been validated using extensive simulations. From the end-user's point of view the system provides a non-invasive, easy to setup, and accurate application to control the quality of the manufacturing process and to provide input for corrections at an early stage of the production. Results of an on-site measurement on a large cylinder conclude this contribution.