DE202016008273U1 - Device for measuring the width of a metal strip produced by strip rolling - Google Patents

Abstract

Apparatus for determining a first searched distance (x1) of a first edge of a metal strip from a first imaginary measurement line (g1) perpendicular to the width (b) of the metal strip, comprising: at least a first microwave device (S1) of a first type and at least two each of which is arranged at first known distances (y1, y3) first microwave devices (E1, E3) of a second type, which are arranged together on the first imaginary measuring line (g1), wherein the device is arranged to: determine respective first transit times of the microwave signals reflecting, reflected from the first edge of the metal strip, respective first distances (d2 + d1, d2 + d3) between the first first type microwave device (S1) and the second type second microwave devices (E1, E3); Determining the respective first distances (d2 + d1, d2 + d3) from the respective first propagation times of the microwave signals; and determining the first sought distance (x1) by means of trigonometric relationships between the first known distances (y1, y3) and the distances (d2, d1, d3) which can be determined therefrom and from the first distances (d2 + d1, d2 + d3) first microwave device (S1) of the first type and the first microwave device (E1, E3) of the second type of the first edge of the metal strip.

Description

Technical area:

The invention relates to a device for determining the positions of the edges and the width of a metal strip.

State of the art:

Such devices are z. B. off DE 10 2005 051 053 A1 . DE 41 24 034 A1 . DE 198 39 287 A1 . DE 41 26 921 A1 and DE 34 42 154 A1 known.

For technological reasons, non-contact and wear-free devices for bandwidth measurement are to be used as a priority. Sensors for measuring the width of metal strips in the current production are also partially exposed to elevated temperatures or intense dust (possibly also metallic abrasion) and in particular high humidity and mist of rolling emulsion or oil. As a result, optical measuring systems (as in, for example, DE 10 2005 051 053 A1 and DE 41 24 034 A1 ), such as cameras or laser scanners for non-contact measurement of bandwidth susceptible to interference, thus inaccurate, and often fail completely.

In addition, the practical operation of conventional optical measuring systems for determining the width of metal strips also results in incorrect measurements due to flatness deviations (waviness) and vibrations.

Inductive sensors (as in eg DE 41 26 921 A1 ) do not achieve the accuracy in the sub-mm range by far, as z. B. to ensure the guaranteed order width on the finished cold strip is required. Therefore, they are only used to record the deviation from the center of the belt and the middle of the machine in the case of belt running controls, since accuracy in the mm range is sufficient here. This equally applies to bandwidth measurement applications based on ultrasonic sensors (as in e.g. DE 34 42 154 A1 ).

EP 1 813 912 A1 discloses a device for determining the position of metallic bands by means of radar. In a comparatively general description, this patent application describes distance measurements at the edges of steel strips by radar, but only for the center positioning of these steel strips as they pass through annealing furnaces. With the solution there, a sufficiently accurate determination in the sub-mm range of the actual width of the continuous band can not be made. In one embodiment of this device so-called Vivaldi sensors in the low frequency range (0.8-4 GHz) are used by the company EMG. As a result, the sensor resolution and thus the measurement accuracy is limited (practically in the mm range).

The goal of EP 1 813 912 A1 is, in accordance with its application for the tape running control, only the determination of the position of the tape edges and from this the position of the tape center (for the determination of the exact bandwidth, however, is not required) relative to the surrounding equipment, which is traversed by the tape. The influence of banding, flatness defects u. Ä. On the measurement accuracy, as z. B. is also important in optical systems, additionally affects the measurement error and could by the in the EP 1 813 912 A1 described measuring arrangement can not be compensated.

Disclosure of the invention:

The object of the invention is therefore to provide a robust and simplified device which enables the detection of the bandwidth with a measurement accuracy and reproducibility in the long-term use in the sub-mm range (preferably below 0.1 mm) even under the adverse conditions of use of the rolling mills ( Vapors, dust / emulsion in the atmosphere, high temperatures).

The object is achieved with the subject matter of the independent claims.

The basic idea of the invention is to determine the band edge position or the bandwidth of metallic bands with two or more radar sensors, preferably high-frequency sensors in the range 30 to 300 GHz of the type FMCW: Frequency Modulated Continuous Wave.

A radar sensor consists of an oscillator that generates microwaves with the frequency between 0.3 and 300 GHz (microwave radiation) and transmits them by means of an antenna. A receiver detects the radiation reflected by objects in the vicinity of the radar sensor via a second antenna. The distance of the radar sensor to each tape location is proportional to the transit time between transmitted and received wave.

The device according to the invention is designed to determine the position of both band edges and from there the bandwidth of a metal band. The metal band can be steel, aluminum or non-ferrous metal.

In one embodiment, the device has on each side of the metal strip two or more radar sensors (including evaluation units) on an imaginary measuring straight line perpendicular to the width of the metal strip, which detect the position of the strip edges. In other words, the distances between the sensors and the respective edge of the metal strip are measured. With the help of these distances and the known positions of the radar sensors, the width of the metal strip can be determined.

An advantageous embodiment of the invention provides to use radar sensors with separate transmitting and receiving antenna to detect and compensate for disturbances such as band vibrations / edge ripples. At least two, better three receiving antennas and one transmitting antenna (no antenna array) should be used, as in 1 shown. In this case, the respective band edge is detected by the three receivers, from which the distances d ₁ , d ₂ , and d ₃ or d ₄ , d ₅ and d ₆ result. Ideally, ie if there are no interferences, the distances d ₁ and d ₃ or d ₄ and d _{6 are} equal, and the band edge positions relevant for determining the bandwidth are d ₂ and d ₅ . If the tape swings down ( 2 ), the decisive for the bandwidth determination distance x ₁ (or x ₂ ) from the signals of the transmitter / receiver, and determine the trigonometric relationships of the sensor arrangement. If the band swings upwards, a corresponding situation results which allows an analogous determination of the band edge position or bandwidth.

In this way it is possible to determine the width of a metal strip very precisely.

In an advantageous embodiment of the arrangement, the receivers E1 and E3 or E4 and E6 are displaceable, so that the distance y ( 2 ) can be adapted to the installation situation and the amplitude of the occurring band vibrations / ripples.

In one embodiment of the arrangement according to the invention ( 3 ), additional sensors can be used to compensate for a possibly occurring transverse bow (cross bow) in the bandwidth determination.

It may also be sufficient to use fewer receivers, as in 4 displayed.

The determination of the strip edge position or bandwidth with the arrangement according to the invention is possible with a better accuracy, because steam and other impurities in the propagation path of the electromagnetic radiation in comparison to a light radiation have less influence. A radar measuring system is more robust compared to an optical measuring system. The required installation space is comparatively low. Due to the better accuracy and availability of the band edge position or bandwidth measurement according to the invention, the product quality and process stability can be increased and trimming scrap can be saved.

Brief description of the drawings

The invention is explained in more detail below with reference to an embodiment shown in the drawing.

Show it:

1 1 is a schematic representation of an exemplary embodiment of an arrangement according to the invention for determining the strip edge position or bandwidth;

2 a schematic representation of the arrangement for the compensation of band vibrations / ripples (here, by way of example, the case that the band oscillates after lower),

3 a schematic representation of the arrangement for the compensation of band vibrations / undulations and cross bow,

4 a schematic representation of the arrangement with fewer receivers,

5 a schematic representation of the trigonometric relationships in the arrangement with fewer receivers, based on the determination of the band edge position can be done,

6 a schematic representation of the arrangement for determining the width of a metal strip.

1 1 schematically shows an exemplary embodiment with the metal strip 1 whose bandwidth b is to be determined, and two radar sensors each installed at a distance from the strip edge consisting of two receivers E1 (or E4) and E3 (or E6) and one transmitter / receiver Unit E2 + S1 (or E5 + S2). In the ideal situation shown (without band vibrations / ripples), the distances d ₂ and d _{5 are} sufficient for determining the bandwidth.

Now swing the tape down, as in 2 ₁ , the distance x ₁ relevant for the determination of the bandwidth can be determined from the signals of the transmitter / receiver and the trigonometric relationships of the sensor arrangement. To this end, each receiver provides a distance which is e = c * T * fb / B, where c represents the propagation velocity of the electromagnetic waves in space, T the length of the frequency modulated signal, fb the intermediate frequency and B the modulation bandwidth. Each distance e ₁ = d ₁ + d ₂ to e ₆ = d ₅ + d ₆ comprises the sum of the distances from the transmitter to the metal band and from there back to the corresponding receiver. The distance x ₁ results from the combination of trigonometric relations (Pythagoras, cosine phrase, etc.). Even in certain embodiments, a triple-redundant determination of x _{1 is} possible.

In 3 is an advanced array of radar sensors that serves to compensate for any possible transverse bow in addition to band vibrations / ripples. Of course, any number can be used above the band, but at least one sensor (E8 + S4), but better three sensors (E7 + S3, E8 + S4 and E9 + S5).

4 shows an arrangement of the sensor units with only one transmitter S1 (or S2) and two receivers E1 and E3 (or E4 and E6). Thus, an accurate determination of the bandwidth with compensation of the band oscillations / ripples is possible.

For such an arrangement is based on 5 shown as the distance x _{1 of} the first edge of the metal strip of a first imaginary measuring straight line g1, which is perpendicular to the width b of the metal strip, can be determined.

5 shows a first microwave transmitter S1 and at least two of them respectively disposed in the first known distances y _1, y ₃ first microwave receivers E1, E3, which are arranged together on the first imaginary straight line g1 measurement.

In one step, the respective first propagation times of the microwave signals can be determined, which reflect from the first edge of the metal strip respective first distances e ₁ = d ₂ + d ₁ and e ₃ = d ₂ + d ₃ between the first microwave transmitter S1 and the first Return microwave receivers E1, E3 of the second type.

In a further step, the respective first distances e ₁ and e ₃ can be determined from the respective first transit times of the microwave signals.

In a further step, the first sought distance x _{1 of} the first edge of the metal strip from the measuring line g ₁ can then be determined by trigonometric relationships between the first known distances y ₁ , y ₃ and the first and the first distances e ₁ = d ₂ + d ₁ and e ₃ = d ₂ + d ₃ determinable distances d ₂ , d ₁ , d _{3 of} the first microwave transmitter S1 and the first microwave receiver E1, E3 are determined from the first edge of the metal strip as follows.

The following five equations can for the five unknown distances x ₁ , z, d ₁ , d ₂ , d ₃ in the arrangement according to 5 be set up: x ₁ ² + (y ₁ + z) ² = d ₁ ² Equation 1 x ₁ ² + z ² = d ₂ ² Equation 2 x ₁ ² + (y ₃ - z) ² = d ₃ ² Equation 3 d ₁ + d ₂ = e ₁ Equation 4 d ₂ + d ₃ = e ₃ Equation 5

From Equation 1 follows: x ₁ ² + y ₁ ² + 2y ₁ z + z ² - d ₁ ² = 0 Equation 6

From equation 3 follows: x ₁ ² + y ₃ ² - 2y ₃ z + z ² - d ₃ ² = 0 Equation 7

From equation 2 follows: x ₁ ² = d ₂ ² - z ² Equation 8

If equation 8 is used in equation 6, it follows:

If equation 8 is used in equation 7, it follows:

From equation 4 follows: d ₁ = e ₁ -d ₂ Equation 11

From equation 5 follows: d ₃ = e ₃ - d ₂ Equation 12

If equation 9 is used in equation 10, it follows:

If equation 11 and equation 12 are used in equation 13, it follows that

By equation 14, d ₂ can be calculated. By equation 11 and equation 12, d ₁ and d ₃ can be calculated. By equation 9 or equation 10, z can be calculated. Finally, by equation 8, the first searched distance x ₁ can be calculated. x ₁ = √ d₂² - z²

6 shows a device for determining the width b of a metal strip between a first and a second edge of the metal strip. The apparatus comprises a first microwave transmitter S1 and at least two first microwave receivers E1, E3, each arranged at first known distances y ₁ , y ₃ , which together lie on a first imaginary measuring line g ₁ which is perpendicular to the width b of the metal strip first sought distance x ₁ are arranged.

In addition, the device has a second microwave transmitter S2 and at least two second microwave receivers E4, E6, each arranged at second known distances y ₄ , y ₆ , which together extend on a second imaginary measuring line g ₂ which is perpendicular to the width b of the metal strip a second sought distance x ₂ are arranged.

The apparatus is configured to determine respective first durations of the microwave signals reflected from the first edge of the metal strip by respective first distances d ₂ + d ₁ , d ₂ + d ₃ between the first microwave transmitter S1 and the first microwave receivers E1, E3. The device is further configured to determine the respective first distances d ₂ + d ₁ , d ₂ + d ₃ from the respective first propagation times of the microwave signals.

The apparatus is further configured to determine the first sought distance x ₁ using trigonometric relationships between the first known distances y ₁ , y ₃ and the one therefrom and the first distances e ₁ = d ₂ + d ₁ and e ₃ = d ₂ + d ₃ determinable distances d ₂ , d ₁ , d _{3 of} the first microwave transmitter (S1) and the first microwave receiver (E1, E3) from the first edge of the metal strip.

The apparatus is configured to determine respective second propagation times of the microwave signals reflecting from the second edge of the metal strip respective second distances e ₄ = d ₅ + d ₄ and e ₆ = d ₅ + d ₆ between the second microwave transmitter S2 and the second microwave receivers Travel E4, E6. The device is further configured to determine the respective first distances e ₄ and e ₆ from the respective second propagation times of the microwave signals.

The apparatus is further configured to determine the second sought distance x ₂ using trigonometric relationships between the second known distances y ₄ , y ₆ and the one therefrom and the second distances e ₄ = d ₅ + d ₄ and e ₆ = d ₅ + d ₆ determinable distances d ₅ , d ₄ , d _{6 of} the second microwave transmitter S2 and the second microwave receiver (E4, E6) of the second edge of the metal strip.

Furthermore, the device is configured to determine the width b as the difference between the known distance d of the first of the second imaginary parallels and the first x ₁ and the second x ₂ sought distances, which respectively consist of trigonometric relationships from the first distances d ₁ , d ₃ and the first known distances y ₁ , y ₃ and the second distances d ₄ , d ₆ and the second known distances y4, y6.

Finally, the device is configured to determine the width b of the metal strip as the difference between the known distance d of the first imaginary measuring line g ₁ from the second g ₂ imaginary measuring line g ₂ and the first searched distance x ₁ and the second searched distance x ₂ .

In this case, the first searched distance x ₁ and the second searched distance x _{2 can be} as after 5 be determined. As in 3 can add additional microwave receivers E2, E5 at the microwave transmitter S1 and S2 are provided. Then, the distances d ₂ and d _{5 of} the microwave transmitters S1 and S2 from the first and second edges of the metal strip can be more easily determined from the transit times to the microwave receivers E2, E5. This is followed easily by the equations 11 and 12, the distances d ₁ and d ₃ and, analogously, the distances d ₄ and d ₆ .

und entsprechend

und damit

For the arrangement in 6 also applies according to the cosine theorem d ₃ ² = d ₁ ² + (y ₁ + y ₃ ) ² - 2d ₁ (y ₁ + y ₃ ) cosθ ₁ . Furthermore, applies sinθ ₁ = x₁ / d₁. So that applies

and accordingly

and thus

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102005051053 A1 [0002, 0003]
• DE 4124034 A1 [0002, 0003]
• DE 19839287 A1 [0002]
• DE 4126921 A1 [0002, 0005]
• DE 3442154 A1 [0002, 0005]
• EP 1813912 A1 [0006, 0007, 0007]

Claims (10)

Apparatus for determining a first searched distance (x ₁ ) of a first edge of a metal strip from a first imaginary measurement line (g ₁ ) perpendicular to the width (b) of the metal strip, comprising: at least one first microwave device (S1) of a first type; at least two first microwave devices (E1, E3) of a second type arranged respectively at first known distances (y ₁ , y ₃ ), which are arranged together on the first imaginary measuring line (g ₁ ), the device being arranged to: determine respective first propagation times of the microwave signals reflecting from the first edge of the metal strip respective first distances (d ₂ + d ₁ , d ₂ + d ₃ ) between the first first type microwave device (S1) and the first microwave devices (E1, E3) second type back; Determining the respective first distances (d ₂ + d ₁ , d ₂ + d ₃ ) from the respective first propagation times of the microwave signals; and determining the first sought distance (x ₁ ) by means of trigonometric relationships between the first known distances (y ₁ , y ₃ ) and the distances that can be determined therefrom and from the first distances (d ₂ + d ₁ , d ₂ + d ₃ ) ( d ₂ , d ₁ , d ₃ ) of the first microwave device (S1) of the first type and the first microwave devices (E1, E3) of the second type of the first edge of the metal strip. The apparatus of claim 1, wherein the at least one first microwave device (S1) of the first type comprises at least one microwave transmitter and the at least two first microwave devices (E1, E3) of the second type comprise at least two microwave receivers. The apparatus of claim 1, wherein the at least one first microwave device (S1) of the first type comprises at least one microwave receiver and the at least two first microwave devices (E1, E3) of the second type comprise at least two microwave transmitters. Device according to one of claims 1 to 3 for determining the width (b) of the metal strip based on a second searched distance (x ₂ ) of a second edge of the metal strip from a second imaginary measuring line (g ₂ ) perpendicular to the width (b) of the Metal bands extends, further comprising: at least one second microwave device (S2) of the first type and at least two of them in second known distances (y ₄ , y ₆ ) arranged second microwave devices (E4, E6) of a second type, which together on the second imaginary measuring straight lines (g ₂ ) are arranged, wherein the device is further adapted to: determine respective second propagation times of the microwave signals reflecting from the second edge of the metal strip respective second distances (d ₅ + d ₄ , d ₅ + d ₆ ) between the second microwave device (S2) of the first type and the second microwave devices (E4, E6) of the second type; Determining the respective second distances (d ₅ + d ₄ , d ₅ + d ₆ ) from the respective second propagation times of the microwave signals; and determining the second distance (x ₂₎ using trigonometric relationships between the second known distances (y _4, y ₆₎ and the thereof, and from the second distance (d ₅ + d _4, d ₅ + d ₆₎ determinable intervals (d ₅ , d ₄ , d ₆ ) of the second microwave device (S2) of the first type and the second microwave devices (E4, E6) of the second type of the second edge of the metal strip; and determining the width (b) as a difference from the known distance (d) of the first (g ₁ ) from the second (g ₂ ) imaginary measuring line and the first (x ₁ ) and the second (x ₂ ) sought distances. Apparatus according to claim 4, wherein the at least one first microwave device (S1) of the first type comprises at least one microwave transmitter and the at least two first microwave devices (E1, E3) of the second type comprise at least two microwave receivers. Apparatus according to claim 4, wherein the at least one first microwave device (S1) of the first type comprises at least one microwave receiver and the at least two first microwave devices (E1, E3) of the second type comprise at least two microwave transmitters. An apparatus according to claim 4, wherein the first and second microwave devices (S1, S2) of the first type each have an additional first and second microwave device (E2, E5) of the second type to additionally define their respective first and second distances (d ₂ , d ₅ ) of the first and second edges, respectively, based on the propagation times of the microwave signals reflecting first and second edges (e ₂ , e ₅ ) of the first and second microwave devices (S1, S2) from the first and second edges of the metal strip, respectively Type and the additional first and second microwave device (E2, E5) of the second type. Apparatus according to claim 7, wherein the first and second microwave devices (S1, S2) of the first type and the additional first and second microwave devices (E2, E5) of the second type are arranged on a transversal to the metal band imaginary middle straight through the metal strip. Device according to one of claims 4 to 8, wherein the first (y ₁ , y ₃ ) and second (y ₄ , y ₆ ) known distances of the first microwave devices (E1, E3) of the second type of the first microwave device (S1) from the first Type and the second microwave devices (E4, E6) of the second type of the second microwave device (S2) of the first type are all the same size (y = y ₁ = y ₃ = y ₄ = y ₆ ), whereby in the case that d ₁ = d ₃ and d ₄ = d _{6 is} determined, simplifies x ₁ and x ₂ to x ₁ = d ₂ and x ₂ = d ₅ can be determined. Device according to one of the preceding claims, further comprising at least one, preferably three, further microwave transmitter (s) (S3, S4, S5), each together with at least one, preferably three, further microwave receiver (s) (E7, E8, E9) an imaginary parallel to the width (b) of the metal strip are arranged above this in order to determine the distance, preferably the respective distances (d ₇ , d ₈ , d ₉ ), preferably, the third microwave receiver (s) (s) (E7, E8, E9) of the metal strip to compensate for a possible transverse arc of the metal strip when determining the width (b) of the metal strip.

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