DE102023110189A1
Abstract
The measurement method described here is based on the shading technique, which is used for the digitization of almost rotationally symmetrical components during the ongoing process. The accuracy of the method is increased by using an expanded light beam to illuminate the component, which allows any desired increase in the shadow to be achieved. The limits of the enlarged shadow are fully recorded using a discontinuous line detector in order to calculate the radius/diameter of the component. The disturbance parameters of a rotating system are then determined by rotating the component and corrected mathematically. In addition, the advantages of the method are particularly evident in the fact that a light source is used without complex beam guidance optics – as in the case of a telecentric light source.
There are several advantages to the state of the art in radius/diameter measurement (filament winding process). The contactless measurement using shading technology:
– enables higher measurement and repeatability accuracy
– reduces machine downtime
– prevents the measurement results from being influenced by touching the component and handling the measuring device itself (e.g. pulling, measuring tape applied)
– is independent of layer type, number of layers and stacked component wall thickness
– prevents the negative influence of the measurement on the quality of the fiber band and stacked component (necking)
– enables a continuous digitalization of the manufacturing process including possible forecasts and control measures regarding dimensions and quality parameters of the wound component during its production
Claims
This invention relates to a method for the calibration-free determination of the radius of an almost rotationally symmetrical body (2) by means of the shading technique and a device consisting of a discontinuous line detector (5)(6) which is composed of one or more spatially offset and as a whole continuous rows of unlimited length of individual line detectors, as well as a light source which emits a light beam (1) which is divergent in the long axis and partially collimated in the short axis. The device is designed in such a way that the upper (3) and/or lower shadow boundaries (4) of the illuminated body are continuously and clearly recorded with a varying radius of the almost rotationally symmetrical body and are used to calculate the diameter/radius in relation to the axis of rotation. To calculate the average diameter of an almost rotationally symmetrical body, at least one complete revolution of the body in the measuring range or of the entire measuring unit around the axis of rotation of the body is required. pers is necessary, whereas for the calculation of the diameter of an ideal rotationally symmetric body no rotation in the measuring range is necessary. A light beam that strongly diverges in the y-direction and is slightly collimated in the x-direction (1) illuminates a rotating body (2). This creates a shadow projection with two shadow boundaries (3) and (4). The light beam is collimated in the x-direction such that the rows of the individual detectors (5) and (6) would be completely illuminated in the x-direction if there were no rotating body (2). The shadow boundaries (3) and (4) are detected by at least one individual detector (7). Each individual detector provides an intensity curve over the position. To determine the position of the shadow boundaries (3) and (4), only the individual detectors (7) which show a significant change in the intensity curve are used. The positions of the shadow boundaries can be calculated from the intensity curve of the upper shadow boundary (8) and the lower shadow boundary (9).
Schuller, V., Rapmund, P., Schwarz, M., & Schäfer, W. (2024). Method and device for the calibration-free determination of the radius of an almost rotationally symmetrical body using shading technology (DE Patent No. DE102023110189A1). German Patent Office. https://patents.google.com/patent/DE102023110189A1/en