AT509606B1

AT509606B1 - Probe, use of the probe, and method for the photogrammetric measurement of a diameter and a position of a cylindrical roll

Info

Publication number: AT509606B1
Application number: AT982011A
Authority: AT
Inventors: Wolfgang Ing Hausleithner; Johann Roland
Original assignee: Siemens Vai Metals Tech Gmbh
Priority date: 2011-01-25
Filing date: 2011-01-25
Publication date: 2011-10-15
Also published as: CN102620652A; DE102011084522A1; AT509606A4

Description

Austrian Patent Office AT 509 606 B1 2011-10-15

description

PROBE, USE OF THE PROBE, AND METHOD FOR THE PHOTOGRAMMETRIC MEASUREMENT OF A DIAMETER AND A POSITION OF A CYLINDRICAL ROLL

The present invention relates to a probe, a measuring system, the use of the probe for scanning a strand guide roller in a continuous casting machine and a method for photogrammetric measurement of a diameter and a position of a cylindrical roller by a measuring system.

Specifically, the invention relates to a probe for scanning a cylindrical roller, comprising a probe body which is rigidly connected to at least a first sensing surface.

From the sales prospectus of the company AICON 3D Systems GmbH entitled "Moenpect Technology, Modular portable CMMs " (see http://www.aicon.de/daten/downloads/products/Mobilelnspe_ctTechnology/AICON MIT-brochure en.pdf) is a probe with a designed as a handle probe body is known, the probe body is rigidly connected to a single first touch surface , Although this probe is well-suited for scanning any surface contours, its use in cylindrical rollers is disadvantageous because several, more specifically at least three, surface points must be scanned separately to allow photogrammetric measurement of a diameter and location of the roll. A probe for sensing a cylindrical roller capable of detecting the diameter and position of the roller (ie, the position and the diameter by the probe using a measuring system by means of a single scanning operation of the roller) by a single scanning operation is not understood not known to the art.

From the document EP 0 881 461 A2 a method for the photogrammetric measurement of a surface point by a measuring system and by means of a probe is known. However, there is no indication as to how the known method would be modified, so that a diameter and a position of a cylindrical roller can be determined by means of a single scanning step and a single measurement image (single shot).

The object of the invention is to provide a probe and a method for photogrammetric measurement of a diameter and a position of a cylindrical roller, so that by means of the probe and a measuring system both the position and the diameter of the roll with high accuracy by means of a single scanning step of the roll and can be determined by means of a single measurement image.

This object is achieved by a probe of the aforementioned type, wherein the probe has at least two first touch surfaces which are rigidly connected to the probe body, wherein at least two points on a lateral surface of the roller simultaneously touched by the first touch surfaces are; - At least a second touch surface which is connected to a measuring bracket, wherein the measuring bracket is designed to be movable relative to the probe body, so that at least one point on the lateral surface of the second sensing surface can be touched; and [0009] - a plurality of first and second target elements, wherein at least two first target elements are assigned to the touch probe body and at least one second target element is assigned to the measuring bow.

The particular embodiment of the probe by a probe body, the at least two first touch surfaces and two first target elements are assigned, and a measuring bracket, which is assigned at least a second touch surface and at least a second target element, allows the detection of the diameter and the position of a Roll by means of a single scan of the roll. Whether the probe body is realized as a single component or, for example, by means of a plurality of sheet-metal bent parts plays no role in the function of the probe. By the first touch surfaces at least two points are detected on the lateral surface of the roller. Another point on the lateral surface of the roller is detected by a measuring bracket, which is relatively movable to the probe body. Since, according to the laws of geometry, three points span a plane, this uniquely determines the position of the roll as well as the diameter of the roll. The first and second target elements, which may be formed, for example, as reflectors, as transmitters or else as so-called active reflectors, allow a measuring system to unambiguously determine the position and the diameter of the roller, the probe body having at least two, preferably greater than or equal four , first target elements, and the measuring bracket at least one, preferably greater than or equal to two, second target elements are assigned. As a result of this embodiment of the measuring probe, the time for determining a diameter and a position of a roll is reduced to at least one third, since at least three separate scanning operations of the lateral surface of the roll are necessary with the prior art measuring probes.

According to an advantageous embodiment, the probe body on a handle for holding the probe. This will increase the ergonomics of the probe.

According to an advantageous embodiment, the handle has a trigger for triggering a camera of a measuring system, wherein the trigger signal is technically connectable to the camera. As a result, both the scanning of the role as well as the triggering of a camera of a measuring system by a single person by means of one-handed operation possible.

According to one embodiment, the measuring bracket is rotatably arranged on the probe body. According to an alternative embodiment, the measuring bracket is slidably disposed on the probe body, for example. That the measuring bracket is pressed against the lateral surface of the roller via a prestressed spring.

By a cylindrical or spherical configuration of a first or second sensing surface of the contact between a tactile surface and the lateral surface of the roller is reliably ensured; This increases the accuracy of the measurement. The design of the touch surfaces with a hardness of more than 38 HRC ensures that the probe is wear-resistant, whereby a high measurement accuracy is ensured even after repeated use.

According to one embodiment, a first or second target element is designed as a reflector for reflection of electromagnetic waves in the visible light, infrared or ultrasound.

According to a further embodiment, a first or second target element as a transmitter for emitting electromagnetic waves in the visible light, infrared or ultrasound is formed, preferably in the range of the wavelength of a laser in the visible light range.

According to an advantageous embodiment, a first or second target element on both a reflector and a transmitter, this combination is often referred to as so-called. "Active reflector". (See, for example, http://www.sy-merger.de/MOPS/web-content/Radarreflek-tor.html) is called.

A measuring system for the photogrammetric measurement of a diameter and a position of a cylindrical roll by means of a single scanning operation comprises - at least four reference target elements which are positionable in the spatial environment of the roll; A probe; At least one camera, preferably at least three cameras, for capturing an image; and [0022] - an evaluation unit which can be connected to the camera by signal technology, the Austrian Patent Office AT 509 606 B1 2011-10-15

Evaluation unit for photogrammetric measurement of a diameter and a position of the roller is formed.

The reference target elements serve to define the position of the stationary or mobile camera or the cameras with respect to the touch probe. One or preferably several cameras are used to take a picture, so that the position and the diameter of the roll can be determined photogrammetrically by means of the evaluation unit from the image.

According to a simple embodiment, the evaluation unit is designed as a PC.

Due to the many strand guide rollers in a continuous casting machine, which must be precisely adjusted or readjusted after wear of the rollers, it is advantageous to use the probe or the measuring system for scanning a strand guide roller in a continuous casting machine. It is of course equally advantageous to use the probe for scanning roller table rollers in a rolling mill.

The object according to the invention is likewise achieved by a method of the type mentioned at the outset, having the following steps: calibrating the measuring system, comprising at least four reference target elements, a measuring probe, at least one camera, and an evaluation unit; - Scanning of the role by the probe, so that at least two first touch surfaces and at least a second touch surface of the probe touch a lateral surface of the roller; - Recording at least one measurement image by means of the at least one camera, wherein the measurement image at least three first and second target elements and a plurality of reference target elements images; - Determining the position and the diameter of the roll by a photogrammetric evaluation of the measurement image.

Advantageously, the following steps are carried out during the calibration of the measuring system: - Positioning of a marking body in the spatial vicinity of the roll; - Attaching at least four reference target elements in the spatial proximity of the roll; - Recording at least one reference image by means of the at least one camera, wherein the reference image images at least the marking body and the reference target elements.

A marking body is e.g. known from DE 10 2006 021063 B3. Due to the position of the marker body and the reference target elements, the position of the camera with respect to the reference target elements is clearly defined. As a result, when taking a measurement image in the course of the photogrammetric measurement of a roll, it is even possible to move the camera with respect to the roll. The reference target elements are substantially fixed target elements (e.g., reflectors or transmitters, see claims 6 to 7), e.g. be mounted on the segment frame of a strand guide segment.

If the camera can be kept stationary in the time between the recording of multiple measurement images, it is advantageous that after the calibration, the position and the position of the camera relative to the reference target elements by a photogrammetric evaluation of the reference image is determined the position and position of the camera are the basis for the simultaneous determination of the position and the diameter of the roll.

Further advantages and features of the present invention will become apparent from the following description of non-limiting embodiments, reference being made to the following figures, which show: Figure 1a is an elevational view of a first type of probe 3/13 Austrian Patent Office 1, 2, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 6, 5, 6, 5, 6, 5, 6, 5, 6, 5, 6, 5, 6, 5, 6. FIG. 7 is a side view of the probe of FIG. 1a; FIG. 2a and 2b each have an elevational view of the probe according to FIGS. 1a and 1b during the scanning of a cylindrical roller; 3 is a perspective view of a second type of probe in scanning a roll; 4 is a perspective view of a third embodiment of a probe when scanning a roll; 5 is a perspective view of a fourth design of a probe; 6 shows an overview image with a measuring system for the photogrammetric measurement of a diameter and a position of a roll by means of a single scanning process; and an overview picture showing the steps in the calibration of the measuring system.

In Figures 1a and 1b, a first embodiment of a probe 1 for scanning a cylindrical roller in the course of the photogrammetric measurement of the diameter and the position of the roller is shown. The probe 1 comprises a rigid measuring probe body 3 made of sheet metal, which is connected to two first sensing surfaces 4a and 4b. A measuring bracket 7 is designed to be movable relative to the probe body 3 via a rotation axis 17 arranged on the probe body 3, a second sensing surface 5 being arranged at one end of the measuring bracket 7. In order to enable the photogrammetric measurement of the roller, both the probe body 3 and the measuring bracket 7 on a plurality of target elements 8 and 9, wherein five target elements on the probe body 3 and two target elements on the measuring bracket 7 are arranged. In order to ensure a well-defined contact between the roller and the first and second touch surfaces 4a, 4b and 5, these touch surfaces are cylindrical. It can be seen from FIG. 1b that the probe body 3 is connected to a handle 10, the handle 10 preferably having a trigger 11 for triggering a camera of a measuring system.

In the figures 2a and 2b of the probe 1 according to the figures 1a and 1b in the sampling of a cylindrical strand guide roller 2 is shown. In this case, the probe 1 is placed on the roller 6, so that the probe 1 via the first touch surfaces 4a and 4b with the lying on the outer surface 6 of the roller points and P2 and the second touch surface 5 with the point P3 is connected without play. The measuring bracket 7 in conjunction with the second target elements 9 ensures that even different diameters of strand guide rollers (FIG. 2 a shows a strand guide roller with a smaller diameter than FIG. 2 b) can be reliably measured. In this case, a change in the diameter leads to a different skew angle α of the measuring bow 7 with respect to the symmetry axis of the probe body 3.

Figure 3 shows a second design of a probe 1. The difference from the first design according to Figures 1a and 1b is that - the handle 10 is arranged in the same plane as the probe body 3, wherein the handle rigidly with is connected to the probe body 3, that both the probe body 3 and the handle 10 have first target elements 8, and [0051] that the first and second touch surfaces 4a, 4b and 5 are spherical.

4 shows a third design of a probe 1. This design has four first touch surfaces 4a ... 4d, so that a secure contact between the first touch surfaces 4a ... 4d and the lateral surface 6 of the cylindrical roller 2 is ensured. The measuring bracket 7 is in turn rotatably connected to the probe body 3, so that different diameters of the 4/13 Austrian Patent Office AT 509 606 B1 2011-10-15

Role 2 can be identified by a photogrammetric evaluation safely and with high accuracy.

5 shows a fourth appeal of a probe 1 with four first touch surfaces 4a ... 4d and a hidden behind the probe body 3 second sensing surface 5. In order to increase the accuracy of the detection system, the probe body 3 has five first target elements and the measuring bracket 7 a total of three second target elements 9. In order to increase the ergonomics of the probe, the handle 10 has an oblique angle of attack γ with respect to the probe body 3. In addition, in this embodiment, the first and second touch surfaces 4a ... 4d, 5 formed interchangeable, so that they can be easily replaced in case of damage or wear.

Common to all embodiments is that the first and second aiming elements 8, 9 are formed as reflectors for reflecting electromagnetic waves in the visible light region; Alternatively, an embodiment of the target elements 8, 9 would be possible as a transmitter or as so-called active reflectors. Also, a shift of the wavelengths of the electromagnetic waves in the range of infrared or ultrasound is possible.

FIG. 6 shows a measuring system 13 for the photogrammetric measurement of a diameter of a layer of a cylindrical roll 2 by means of a single scanning step of the roll. The measuring system comprises a camera 12, four reference target elements 14 designed as reflectors, transmitters or active reflectors, a probe 1 and an evaluation unit 15 formed as a PC.

In the photogrammetric measurement of the diameter and the position of a roll 2, the procedure is as follows: After calibration of the measuring system 10, the roller 2 is scanned by the probe 1, so that at least two first touch surfaces and at least one second touch surface of the probe Contact surface of roller 2. Subsequently, a measurement image is taken by the camera 12, wherein the measurement image images at least a plurality of first and second target elements 8, 9 of the probe 1 and a plurality of reference target elements 14. In the simplest geometric case, the two first touch surfaces and the second touch surface span a plane that uniquely defines the position of the roller 2. In addition, the diameter of the roll is clearly defined by the first and second touch surfaces. The evaluation of the position and the diameter of the roll takes place in the evaluation unit 16, which is designed as a PC.

An improvement in the measurement accuracy can be achieved by using a plurality of cameras 12 and / or a plurality of first and second touch surfaces 8,9.

During the calibration of the measuring system 13, a so-called reference image is taken by the camera 12 after the placement of at least four reference target elements 14 and at least one marking body 16 in the spatial vicinity of the roll 2. The position of the camera 12 with respect to the reference target elements 14 is defined by the measurement image, so that it is possible to move the camera 12 between the acquisition of a plurality of measurement images.

In Fig. 7, the steps in the calibration of the measuring system are shown schematically. In this case, a marking body 16, which in turn has a plurality of target elements, and at least four reference target elements 14 are placed in the spatial proximity of a roll. When measuring a plurality of strand guide rollers of a strand guide segment, it is particularly useful to fix the reference target elements 14 on the segment frame. Subsequently, at least one reference image of at least one camera-in FIG. 7, two cameras 12 -is recorded, wherein the cameras are signal-wise connected to the evaluation unit 15. By means of the reference image, the measuring system is completely calibrated.

REFERENCE LIST 1 Probe 2 Roller 3 Probe Body 5/13

Claims

Austrian Patent Office 4a, 4b, 4c, 4d first sensing surface 5 second sensing surface 6 lateral surface 7 measuring bracket 8 first target element 9 second target element 10 handle 11 trigger 12 camera 13 measuring system 14 reference target element 15 evaluation unit 16 marking body 17 Rotational axis P1... P5 point on lateral surface of the roller .alpha., .Gamma. Angles (1) for scanning a cylindrical roller (2), comprising a probe body (3) with at least one first sensing surface (4a, 4b, 4c, 4d) is rigidly connected, characterized by - at least two first touch surfaces (4a, 4b, 4c, 4d) which are rigidly connected to the probe body (3), wherein at least two points (P ^ P2, P3, P4) on a lateral surface ( 6) of the roller (2) can be touched simultaneously by the first touch surfaces (4a, 4b, 4c, 4d); - At least a second touch surface (5) which is connected to a measuring bracket (7), wherein the measuring bracket (7) is designed to be movable relative to the probe body (3), so that at least one point (P5) on the lateral surface (6) of the second Touch surface (5) can be touched; and - a plurality of first and second target elements (8, 9), wherein at least two first target elements (8) the probe body (3) and at least one second target element (9) are associated with the measuring bracket (7).
2. Probe according to claim 1, characterized in that the probe (1) has a handle (11) for holding the probe (1).
3. Probe according to claim 2, characterized in that the handle (11) has a trigger (12) for triggering a camera (12) of a measuring system (13), wherein the trigger (12) is technically connectable to the camera (12) ,
4. Probe according to one of claims 1 to 3, characterized in that the measuring bracket (7) is rotatably mounted on the probe body (3).
5. Probe according to one of claims 1 to 3, characterized in that the measuring bracket (7) is displaceably arranged on the probe body (3).
6. Probe according to one of the preceding claims, characterized in that a first or a second touch surface (4a ... 4d, 5) is cylindrical or spherical.
7. Probe according to one of claims 1 to 6, characterized in that a first or a second target element (8, 9) is designed as a reflector for the reflection of electromagnetic waves in the visible light, infrared or ultrasound.
8. A probe according to one of claims 1 to 7, characterized in that a first or a second target element (8, 9) is designed as a transmitter for emitting electromagnetic waves in the visible light, infrared or ultrasound. 6/13 Austrian Patent Office AT 509 606 B1 2011-10-15
9. measuring system (13) for the photogrammetric measurement of a diameter and a position of a cylindrical roller (2) by means of a single scanning operation, comprising - at least four reference target elements (14) which are positionable in the spatial environment of the roller (2), a probe (1) according to one of claims 1 to 8, - at least one camera (12), preferably at least three cameras, for capturing an image, - an evaluation unit (15) which is signal-technically connectable to the camera (12), wherein the Evaluation unit (15) for photogrammetric measurement of a diameter and a position of the roller (2) is formed.
10. Use of the probe (1) according to one of claims 1 to 8 for scanning a strand guide roller in a continuous casting machine.
11. A method for the photogrammetric measurement of a diameter and a position of a cylindrical roller (2) by a measuring system (13) according to claim 9, characterized by the following steps: - calibrating the measuring system (13), comprising at least four reference target elements (14), a probe (1), at least one camera (12), and an evaluation unit (15); - Scanning of the roller (2) by a probe (1) according to one of claims 1 to 8, so-that at least two first touch surfaces (4a ... 4d) and at least one second touch surface (5) of the probe (1) has a lateral surface (6) touch the roller (2); - Recording at least one measurement image by means of the at least one camera (12), wherein the measurement image at least three first and second target elements (8,9) of the probe (1) and a plurality of reference target elements (14) images; - Determination of the position and the diameter of the roll (2) by a photogrammetric evaluation of the measurement image.
12. The method according to claim 11, characterized in that during the calibration of the measuring system (13) the following steps are carried out: positioning a marking body (16) in the spatial proximity of the roller (2); Attaching at least four reference target elements (14) in the spatial proximity of the roll (2); Taking at least one reference image by means of the at least one camera (12), wherein the reference image images at least the marking body (16) and the reference target elements (14).
13. The method according to claim 12, characterized in that the marking body (16) is removed or covered after taking the reference image.
14. The method according to claim 12, characterized in that after the calibration, the position and the position of the camera (12) relative to the reference target elements (14) is determined by a photogrammetric evaluation of the reference image, wherein the position and the position of the camera (12) the simultaneous determination of the position and diameter of the roll (2). For this 6 sheets drawings 7/13