CN117419649A - Non-contact type online measuring method for thickness of aluminum ingot - Google Patents
Non-contact type online measuring method for thickness of aluminum ingot Download PDFInfo
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- CN117419649A CN117419649A CN202311424755.XA CN202311424755A CN117419649A CN 117419649 A CN117419649 A CN 117419649A CN 202311424755 A CN202311424755 A CN 202311424755A CN 117419649 A CN117419649 A CN 117419649A
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- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 title claims abstract description 34
- 229910052782 aluminium Inorganic materials 0.000 title claims abstract description 34
- 238000000034 method Methods 0.000 title claims description 6
- 238000005259 measurement Methods 0.000 claims abstract description 11
- 238000000691 measurement method Methods 0.000 claims abstract description 9
- 238000012937 correction Methods 0.000 claims description 9
- 230000003287 optical effect Effects 0.000 claims description 7
- 238000004364 calculation method Methods 0.000 claims description 6
- 238000012545 processing Methods 0.000 claims description 6
- 101150066718 FMOD gene Proteins 0.000 claims description 3
- AZDRQVAHHNSJOQ-UHFFFAOYSA-N alumane Chemical group [AlH3] AZDRQVAHHNSJOQ-UHFFFAOYSA-N 0.000 claims description 3
- 238000001914 filtration Methods 0.000 claims description 3
- 238000007781 pre-processing Methods 0.000 claims description 3
- 230000008859 change Effects 0.000 description 2
- 238000004891 communication Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
Classifications
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B11/00—Measuring arrangements characterised by the use of optical techniques
- G01B11/02—Measuring arrangements characterised by the use of optical techniques for measuring length, width or thickness
- G01B11/06—Measuring arrangements characterised by the use of optical techniques for measuring length, width or thickness for measuring thickness ; e.g. of sheet material
- G01B11/0616—Measuring arrangements characterised by the use of optical techniques for measuring length, width or thickness for measuring thickness ; e.g. of sheet material of coating
- G01B11/0625—Measuring arrangements characterised by the use of optical techniques for measuring length, width or thickness for measuring thickness ; e.g. of sheet material of coating with measurement of absorption or reflection
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- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Length Measuring Devices By Optical Means (AREA)
Abstract
The invention discloses a non-contact type online measurement method for aluminum ingot thickness, which relates to the technical field of non-contact type thickness measurement, wherein a laser sensor is electrified from start-up and can be used only after waiting for a long time, so that the field use requirement is difficult to meet.
Description
Technical Field
The invention relates to the technical field of non-contact thickness measurement, in particular to a non-contact type online aluminum ingot thickness measurement method.
Background
Since the temperature is in a high temperature state after the aluminum ingot is produced, a non-contact measurement method is adopted, and laser measurement is a common method in the existing non-contact measurement method.
However, the conventional laser sensor is electrified from the start and needs to wait 6000 seconds for use, because the time stability of the sensor is poor, namely, the sensor measures the same position of the same product at different times from the start of the electrification, the measurement results have larger difference, the waiting time is longer, and the waiting time is shortened.
Disclosure of Invention
In order to solve the technical problems in the background technology, the invention provides a non-contact type online measuring method for the thickness of an aluminum ingot.
The invention provides a non-contact type online measurement method for the thickness of an aluminum ingot, which comprises the following steps:
s1, calculating a time stability compensation value: a compensation plate is arranged at the lower limit of the Z-direction measuring range of the laser sensor, the compensation plate is arranged in a hollow mode, the distance between the sensor and the compensation plate is recorded as Zmin, the middle part of a laser line of the laser sensor can be projected onto an aluminum ingot through the compensation plate and used for measuring the distance of the aluminum ingot, the laser lines on two sides of the laser sensor are blocked by the compensation plate and used for compensation, and the numerical value Ztime of the aluminum ingot after the time stability compensation of the laser sensor is calculated;
s2, data acquisition: after waiting for a certain time, the laser sensor irradiates the laser beam to the surface of the aluminum ingot, and the sensor measures the time delay or angle of the reflected laser beam;
s3, signal processing: preprocessing the original data, including denoising and filtering, so as to eliminate interference which may affect the accuracy, and calibrating the original data, so that an accurate relation is established between the sensor output and the actual thickness;
s4, extracting features, namely calculating a reflection optical path, namely the distance from the laser sensor to the surface of the aluminum chain by measuring the time delay or angle of the light beam according to a laser measurement principle;
s5, thickness calculation: through the measured reflection optical path, the thickness of the aluminum heald can be calculated, assuming that d is the thickness of the measured object, c is the speed of light, Δt is the time difference of the laser beam reflected by the object surface, n is the refractive index of the aluminum ingot, and the thickness of the aluminum heald can be calculated by using the following formula:
d＝(c*Δt)/2n。
preferably, the speed of light c is the speed at which the electromagnetic wave propagates in vacuum, taking a value of 299792458m/s.
Preferably, the compensation plate is a rectangular thin plate, a rectangle is uniformly removed from the middle part of the thin plate to form a rectangular hollow groove, so that when the sensor works, the middle part of the laser line can be projected onto a product to be measured through the compensation plate for measuring the distance of the product to be measured, and the laser lines at two side parts are blocked by the compensation plate for compensation.
Preferably, in S1, after the sensor enters a stable working state, the distance value of the compensation plate at Zmin is read and recorded as Zref, and Zref is a reference value at Zmin. Starting the sensor to be electrified, reading the value of the compensation plate at any moment to be Zcomp, and recording the real-time compensation value at the moment at Zmin as delta fmin, wherein delta fmin is;
formula one: Δfmin=zcomp-Zref;
at the lower limit Zmin and the upper limit Zmax of the sensor range, the two indication values have deviation of the value A after the stability, the real-time compensation value Deltafmin at the Zmin can not be directly used for compensating the error value in the whole range, and a compensation correction value needs to be added. In order to obtain the correction value in the range conveniently, a simplified calculation method is adopted, the deviation A is subjected to linear distribution processing in the whole range, and the correction value at any position is marked as Deltafmod. Zobj is used for representing the wall plate measured value obtained by the sensor at any moment, and delta fmod is;
formula II: Δfmod=a (Zobj-Zmin)/(Zmin-Zmin);
by combining the first formula and the second formula, the numerical value Ztime of the measured target after the time stability (drift) compensation of the sensor can be calculated;
formula III: ztime = Zobj- Δf- Δfmod.
The non-contact online measurement method for the thickness of the aluminum ingot has the following beneficial technical effects:
the laser sensor is electrified from the start, can be used after waiting for a long time, is difficult to meet the field use requirement, shortens the waiting time required for the laser sensor to be electrified to a stable state by adding compensation measures, reduces the drift amount, improves the time stability of the sensor, and enables the sensor to enter the stable working state as soon as possible.
Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.
Drawings
FIG. 1 is a front view of the structure of the present invention;
FIG. 2 is a schematic diagram of the structure of the present invention;
FIG. 3 is a schematic diagram of the structure of the present invention.
Detailed Description
Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar symbols indicate like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are exemplary only for explaining the present invention and are not to be construed as limiting the present invention.
It is to be understood that the terms "center," "longitudinal," "transverse," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counter-clockwise," "axial," "radial," "circumferential," and the like are directional or positional relationships as indicated based on the drawings, merely to facilitate describing the invention and to simplify the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be configured and operated in a particular orientation, and therefore should not be construed as limiting the invention.
Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present invention, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise.
In the present invention, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; may be mechanically connected, may be electrically connected or may be in communication with each other; either directly or indirectly, through intermediaries, or both, may be in communication with each other or in interaction with each other, unless expressly defined otherwise. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.
In the present invention, unless expressly stated or limited otherwise, a first feature "up" or "down" a second feature may be the first and second features in direct contact, or the first and second features in indirect contact via an intervening medium. Moreover, a first feature being "above," "over" and "on" a second feature may be a first feature being directly above or obliquely above the second feature, or simply indicating that the first feature is level higher than the second feature. The first feature being "under", "below" and "beneath" the second feature may be the first feature being directly under or obliquely below the second feature, or simply indicating that the first feature is less level than the second feature.
A non-contact online measurement method for the thickness of an aluminum ingot comprises the following steps:
s1, calculating a time stability compensation value: a compensation plate is arranged at the lower limit of the Z-direction measuring range of the laser sensor, the compensation plate is arranged in a hollow mode, the distance between the sensor and the compensation plate is recorded as Zmin, the middle part of a laser line of the laser sensor can be projected onto an aluminum ingot through the compensation plate and used for measuring the distance of the aluminum ingot, the laser lines on two sides of the laser sensor are blocked by the compensation plate and used for compensation, and the numerical value Ztime of the aluminum ingot after the time stability compensation of the laser sensor is calculated;
s2, data acquisition: after waiting for a certain time, the laser sensor irradiates the laser beam to the surface of the aluminum ingot, and the sensor measures the time delay or angle of the reflected laser beam;
s3, signal processing: preprocessing the original data, including denoising and filtering, so as to eliminate interference which may affect the accuracy, and calibrating the original data, so that an accurate relation is established between the sensor output and the actual thickness;
s4, extracting features, namely calculating a reflection optical path, namely the distance from the laser sensor to the surface of the aluminum chain by measuring the time delay or angle of the light beam according to a laser measurement principle;
s5, thickness calculation: through the measured reflection optical path, the thickness of the aluminum heald can be calculated, assuming that d is the thickness of the measured object, c is the speed of light, Δt is the time difference of the laser beam reflected by the object surface, n is the refractive index of the aluminum ingot, and the thickness of the aluminum heald can be calculated by using the following formula:
d＝(c*Δt)/2n。
this is because the distance that the laser beam travels to and from the surface of the ingot is equal to twice the reflected optical path.
The speed of light is the speed at which electromagnetic waves propagate in vacuum, and is 299792458m/s.
In S1, the time stability drift compensation of the laser sensor is carried out, a high-precision compensation plate is arranged at the lower limit of the Z-direction measuring range of the laser sensor, and the distance between the sensor and the compensation plate is recorded as Zmin;
the compensation plate is a rectangular thin plate with the thickness of 100mm multiplied by 50mm, the middle part of the thin plate is uniformly removed with the thickness of 90mm multiplied by 40mm, when the sensor works, the middle 40mm of the laser line can be projected onto a product to be measured through the compensation plate, and the distance between the laser line and the product to be measured is measured. The laser lines with the two sides of 5mm are blocked by the compensation plate for compensation;
after the laser sensor enters a stable operating state (in this embodiment, after 1200S), the distance value of the compensation plate at Zmin is read and recorded as Zref, which is a reference value at Zmin. Starting the sensor to be electrified when the sensor is started, reading the value of the compensation plate at any moment to be Zcomp, and recording the real-time compensation value at the moment at Zmin as Deltafmin, wherein Deltafmin is as follows:
△fmin＝Zcomp-Zref；
at the lower limit Zmin and the upper limit Zmax of the measuring range of the laser sensor, the deviation of the numerical value a exists between the lower limit Zmin and the upper limit Zmax after the laser sensor is stabilized, the measured value a=0.0024mm, the real-time compensation value Δfmin at the Zmin cannot be directly used for compensating the error value in the whole measuring range, and a compensation correction value needs to be added. In order to obtain the correction value in the range conveniently, a simplified calculation method is adopted, the deviation A is subjected to linear distribution processing in the whole range, and the correction value at any position is marked as Deltafmod. Using Zobj to represent the wall panel measurement value obtained by the sensor at any time, Δfmod is:
△fmod＝A(Zobj-Zmin)/(Zmin-Zmin)；
the numerical value Ztime of the measured target after the time stability (drift) compensation of the sensor can be calculated:
Ztime＝Zobj-Δf-Δfmod。
the sensor is electrified from the start, can be used after waiting for a long time, is difficult to meet the field use requirement, shortens the waiting time required for the laser sensor to be electrified to a stable state by adding compensation measures, reduces the drift amount, improves the time stability of the sensor, and enables the sensor to enter the stable working state as soon as possible.
Comparison experiment:
control group: the drift change amount of the laser sensor under normal condition is measured, and the time is recorded, as shown in figure 1;
experimental group: verifying the compensated measurement result, selecting two laser sensors, starting up and powering on, continuously tracking and observing a certain static target to 7000s, and respectively displaying the indication change conditions of the two sensors as shown in fig. 2 and 3;
as shown in fig. 1-3, as can be seen from fig. 2 and 3, both sensors enter a stable working state after being powered on for 1200s, the data fluctuation amount is within ±0.001mm, and compared with the time before adding compensation, the system advances 4800s to enter a stable stage, and the waiting time of the laser sensor from the power on to the stable state is shortened.
And all that is not described in detail in this specification is well known to those skilled in the art.
The foregoing is only a preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art, who is within the scope of the present invention, should make equivalent substitutions or modifications according to the technical scheme of the present invention and the inventive concept thereof, and should be covered by the scope of the present invention.
Claims (4)
1. The non-contact online measurement method for the thickness of the aluminum ingot is characterized by comprising the following steps of:
s1, calculating a time stability compensation value: a compensation plate is arranged at the lower limit of the Z-direction measuring range of the laser sensor, the compensation plate is arranged in a hollow mode, the distance between the sensor and the compensation plate is recorded as Zmin, the middle part of a laser line of the laser sensor can be projected onto an aluminum ingot through the compensation plate and used for measuring the distance of the aluminum ingot, the laser lines on two sides of the laser sensor are blocked by the compensation plate and used for compensation, and the numerical value Ztime of the aluminum ingot after the time stability compensation of the laser sensor is calculated;
s2, data acquisition: after waiting for a certain time, the laser sensor irradiates the laser beam to the surface of the aluminum ingot, and the sensor measures the time delay or angle of the reflected laser beam;
s3, signal processing: preprocessing the original data, including denoising and filtering, so as to eliminate interference which may affect the accuracy, and calibrating the original data, so that an accurate relation is established between the sensor output and the actual thickness;
s4, extracting features, namely calculating a reflection optical path, namely the distance from the laser sensor to the surface of the aluminum chain by measuring the time delay or angle of the light beam according to a laser measurement principle;
s5, thickness calculation: through the measured reflection optical path, the thickness of the aluminum heald can be calculated, assuming that d is the thickness of the measured object, c is the speed of light, Δt is the time difference of the laser beam reflected by the object surface, n is the refractive index of the aluminum ingot, and the thickness of the aluminum heald can be calculated by using the following formula:
d＝(c*Δt)/2n。
2. the method for non-contact on-line measurement of thickness of aluminum ingot according to claim 1, wherein the speed of light c is the speed of electromagnetic wave propagation in vacuum, and is 299792458m/s.
3. The method for non-contact on-line measurement of aluminum ingot thickness according to claim 1, wherein the compensation plate is a rectangular thin plate, a rectangle is uniformly removed from the middle part of the thin plate to form a rectangular hollow groove, when the sensor works, the middle part of the laser line can be projected onto a measured product through the compensation plate for measuring the distance of the measured product, and the laser lines at two side parts are blocked by the compensation plate for compensation.
4. The non-contact online measurement method of aluminum ingot thickness according to claim 1, wherein in S1, the sensor time stability drift is compensated, and after the sensor enters a stable working state, a distance value of a compensation plate at Zmin is read and recorded as Zref, and Zref is a reference value at Zmin. Starting the sensor to be electrified, reading the value of the compensation plate at any moment to be Zcomp, and recording the real-time compensation value at the moment at Zmin as delta fmin, wherein delta fmin is;
formula one: Δfmin=zcomp-Zref;
at the lower limit Zmin and the upper limit Zmax of the sensor range, the two indication values have deviation of the value A after the stability, the real-time compensation value Deltafmin at the Zmin can not be directly used for compensating the error value in the whole range, and a compensation correction value needs to be added. In order to obtain the correction value in the range conveniently, a simplified calculation method is adopted, the deviation A is subjected to linear distribution processing in the whole range, and the correction value at any position is marked as Deltafmod. Zobj is used for representing the wall plate measured value obtained by the sensor at any moment, and delta fmod is;
formula II: Δfmod=a (Zobj-Zmin)/(Zmin-Zmin);
by combining the first formula and the second formula, the numerical value Ztime of the measured target after the time stability (drift) compensation of the sensor can be calculated;
formula III: ztime = Zobj- Δf- Δfmod.
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