CN113959647B - Leakage detection method and system suitable for high-speed scanning - Google Patents
Leakage detection method and system suitable for high-speed scanning Download PDFInfo
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- CN113959647B CN113959647B CN202111240268.9A CN202111240268A CN113959647B CN 113959647 B CN113959647 B CN 113959647B CN 202111240268 A CN202111240268 A CN 202111240268A CN 113959647 B CN113959647 B CN 113959647B
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- 238000001514 detection method Methods 0.000 title claims abstract description 35
- 230000007246 mechanism Effects 0.000 claims abstract description 47
- 238000000034 method Methods 0.000 claims abstract description 28
- 230000008569 process Effects 0.000 claims abstract description 19
- 238000001914 filtration Methods 0.000 claims abstract description 17
- 238000012545 processing Methods 0.000 claims abstract description 7
- 230000003750 conditioning effect Effects 0.000 claims description 9
- 230000004044 response Effects 0.000 claims description 9
- 238000006073 displacement reaction Methods 0.000 claims description 7
- 238000012360 testing method Methods 0.000 claims description 7
- 230000003321 amplification Effects 0.000 claims description 6
- 238000003199 nucleic acid amplification method Methods 0.000 claims description 6
- 238000013507 mapping Methods 0.000 claims description 3
- 238000011084 recovery Methods 0.000 claims description 3
- 238000011282 treatment Methods 0.000 claims description 3
- 238000007781 pre-processing Methods 0.000 claims 1
- 239000007789 gas Substances 0.000 description 19
- 238000010586 diagram Methods 0.000 description 3
- 230000005611 electricity Effects 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000035484 reaction time Effects 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 230000001360 synchronised effect Effects 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M3/00—Investigating fluid-tightness of structures
- G01M3/02—Investigating fluid-tightness of structures by using fluid or vacuum
- G01M3/04—Investigating fluid-tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point
Abstract
The invention discloses a leak detection system suitable for high-speed scanning, which comprises a sensor module, a detected piece filled with leakage gas, a scanning mechanism, a collecting card, a computer and an ink-jet marking device, wherein the sensor module and the ink-jet marking device are both arranged on the scanning mechanism, the sensor module and the scanning mechanism are both electrically connected with the collecting card, and the scanning mechanism and the collecting card are both electrically connected with the computer. In the invention, after the scanning process is separated from the signal processing process, a zero-phase digital filter can be adopted to avoid position deviation caused by filtering phase delay, and a peak searching algorithm can be adopted to eliminate position deviation related to the leak rate; after the leak point marking process is separated from the scanning process, the scanning mechanism can accurately position the target position for ink-jet marking, and the leak point marking error is reduced. In addition, the method improves the accuracy of the leak location marks without sacrificing the leak detection efficiency.
Description
Technical Field
The invention relates to the technical field of seal detection, in particular to a leak detection method and a leak detection system suitable for high-speed scanning.
Background
The leak detection method using the nitrogen-hydrogen gas as the leakage gas is applied due to the advantages of economy and high precision. At present, in the application of dynamic leak detection, the method of locating and marking leakage in suspicious leak areas such as high-speed scanning welding lines is adopted, leakage signals are collected in the scanning process (some cases can carry out some advanced filtering), and under the condition that the amplitude of the leakage signals or derived signals thereof is higher than a certain threshold value, the existence of the leakage points in the positions is judged, and ink jet is carried out.
The existing leak positioning and marking method has two disadvantages, firstly, positioning deviation exists, a sensor sweeps from the upper part of a leak hole at a certain scanning speed, based on the response characteristic of the sensor, the distance between the position triggering the leakage threshold value and the position of the actual leak point is related to the scanning speed, as shown in fig. 3 delta t1 and delta t2 are related to signal intensity ssi, signal intensity ssi is related to the scanning speed v and the concentration r near the leak point, the concentration r near the leak point is related to the leakage rate Q, and delta t1 and delta t2 are unknown functions of the scanning speeds v and Q, so the corresponding delta s1 and delta s2 cannot be compensated. Meanwhile, the adopted non-zero phase filtering can generate phase delay delta t3, wherein delta t3 is an unknown function of the scanning speed v, Q and the leakage signal frequency f, and cannot be determined to be compensated. Secondly, there is a deviation in the reaction time of the inkjet marking device, and the difference is in the order of 100ms, which may generate marking errors. In a high-speed scanning leak detection method for calculating marks while scanning, the positioning mark position error is in the order of several cm.
Therefore, a method for improving the positioning accuracy and the identification accuracy of the leakage points under high beat conditions is required.
Disclosure of Invention
The invention aims at: in order to solve the above problems, a leak detection method and a leak detection system suitable for high-speed scanning are proposed.
In order to achieve the above purpose, the present invention adopts the following technical scheme:
the utility model provides a be suitable for leak detection system of high-speed scanning, includes sensor module, is full of the piece of examining of leakage gas, scanning mechanism, acquisition card, computer, inkjet marking device, sensor module and inkjet marking device all install on scanning mechanism, sensor module and scanning mechanism all with acquisition card electric connection, scanning mechanism and acquisition card all with electromechanical connection.
Preferably, the sensor module selects a gas sensitive sensor, the gas sensitive sensor is composed of a sensitive element, an adapter plate and a signal conditioning module, the sensitive element is welded on the adapter plate, the adapter plate is connected with the signal conditioning module through a signal wire, and the signal conditioning module performs power amplification, operational amplification, filtering and other treatments on signals and then outputs the signals to the acquisition card through a cable.
Preferably, the scanning mechanism comprises a driving motor, an encoder and a control system, the position information of the encoder can be output to the acquisition card, and the movement of the encoder is controlled by a computer.
Preferably, the computer is provided with signal processing and leakage point positioning software which is independently developed, the leakage point positioning software adopts zero-phase digital filtering pretreatment, and the leakage point position is obtained through a peak searching algorithm and is fed back to a control system of the scanning mechanism.
A detection method based on the leak detection system, comprising the steps of:
s1: placing a detected piece filled with leakage gas on a detection table, and determining time domain deviation delta t through a sensor characteristic test;
s2: replacing the detected piece;
s3: filling a certain pressure of leakage gas into the replaced detected piece, and starting signal acquisition at t6 before the mechanism scans, wherein t6 is not smaller than the width of a zero-phase FIR digital filtering window, and t6 is acquisition time in advance;
s4: the scanning mechanism drives the sensor module to scan along the suspicious region at a certain speed, and a leakage threshold value is determined;
s5: after the scanning is finished, starting to recycle gas, and delaying for a time t6 to stop collecting data;
s6: carrying out zero-phase filtering pretreatment on the signal, obtaining displacement s1 of a peak value corresponding position through a peak searching algorithm, obtaining corresponding displacement deltas through time domain deviation deltat, obtaining a position s0 of a leakage point through compensation of s 1-deltas, and feeding back the position of the leakage point to a scanning mechanism;
s7: the scanning mechanism is positioned to the position of the leakage point and performs ink-jet marking in the process of returning to the original point;
s8: after the gas recovery is finished, the whole detection period is finished, and the step 1 is re-executed.
Preferably, the process of returning the scanning mechanism to the origin does not participate in the acquisition of leakage signals, and the time t4 is reduced by improving the speed of returning the mechanism to the origin so as to meet the time sequence requirement.
Preferably, the leak threshold is determined by scanning leak holes for leak rate under the same conditions.
Preferably, the time domain deviation Δt is determined by the response characteristic of the sensor, and can be compensated by testing the response characteristic of the sensor and mapping to the location domain.
In summary, due to the adoption of the technical scheme, the beneficial effects of the invention are as follows:
in the method, after the scanning process is separated from the signal processing process, a zero-phase digital filter can be adopted to avoid position deviation caused by filtering phase delay, and a peak searching algorithm can be adopted to eliminate position deviation related to the leak rate; after the leak point marking process is separated from the scanning process, the scanning mechanism can accurately position the target position for ink-jet marking, so that the leak point marking error is reduced, and meanwhile, the leak point positioning marking precision is improved by the method without sacrificing the leak detection efficiency.
Drawings
FIG. 1 illustrates a leak detection timing diagram provided in accordance with an embodiment of the present invention;
FIG. 2 shows a schematic diagram of a leak detection system provided in accordance with an embodiment of the present invention;
fig. 3 shows a schematic diagram of a positioning mark error structure provided according to an embodiment of the present invention.
Wherein, (1) and (2) are concentration distribution curves around the leakage holes with different leakage rates, (3) and (4) are signal curves with different intensities, and (5) is a displacement curve.
Legend description:
1. a sensor module; 2. a test piece filled with a leakage gas; 3. a scanning mechanism; 4. a collection card; 5. a computer; 6. an ink marking device.
Description of the embodiments
The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
Referring to fig. 1-3, the present invention provides a technical solution:
the utility model provides a leak detection system suitable for high-speed scanning, including sensor module 1, be full of the detected piece 2 of leaking gas, scanning mechanism 3, collection card 4, computer 5, inkjet marking device 6, sensor module 1 and inkjet marking device 6 are all installed on scanning mechanism 3, sensor module 1 and scanning mechanism 3 all are connected with collection card 4 electricity, scanning mechanism 3 and collection card 4 all are connected with computer 5 electricity;
the sensor module 1 selects a gas sensitive sensor, the gas sensitive sensor is composed of a sensitive element, an adapter plate and a signal conditioning module, the sensitive element is welded on the adapter plate, the adapter plate is connected with the signal conditioning module through a signal wire, the signal conditioning module performs power amplification, operational amplification, filtering and other treatments on signals, and then the signals are output to the acquisition card 4 through a cable, the gas sensitive sensor is a hot wire semiconductor gas sensitive sensor MR511, has low cross sensitivity to background gas and high response speed, and the acquisition card 4 selects a multichannel acquisition card and has the function of high-speed synchronous acquisition;
the scanning mechanism 3 comprises a driving motor, an encoder and a control system, the position information of the encoder can be output to the acquisition card 4, the movement of the encoder is controlled by the computer 5, and the positioning precision of the scanning mechanism 3 is at least one order of magnitude higher than the positioning precision of expected leakage;
the computer 5 is provided with signal processing and leakage point positioning software which is independently developed, the leakage point positioning software adopts zero-phase digital filtering pretreatment, the leakage point position is obtained through a peak searching algorithm and is fed back to the control system of the scanning mechanism 3, the computer 5 adopts a grinding industrial personal computer carrying a Kui 7 processor, the signal processing speed is high, and the deltat 3 can be eliminated by adopting a zero-phase digital filter.
A detection method based on a leak detection system, comprising the steps of:
s1: placing the detected piece 2 filled with the leakage gas on a detection table, and determining a time domain deviation delta t through a sensor characteristic test;
s2: replacing the detected piece;
s3: filling a certain pressure of leakage gas into the replaced detected piece, and starting signal acquisition at t6 before the mechanism scans, wherein t6 is not smaller than the width of a zero-phase FIR digital filtering window, and t6 is acquisition time in advance;
s4: the scanning mechanism 3 drives the sensor module 1 to scan along the suspicious region at a certain speed, a leakage threshold value is determined, and the scanning speed is determined according to the detection efficiency requirement;
s5: after the scanning is finished, starting to recycle gas, and delaying for a time t6 to stop collecting data;
s6: carrying out zero-phase filtering pretreatment on the signal, obtaining displacement s1 of a peak value corresponding position through a peak searching algorithm, obtaining corresponding displacement deltas through time domain deviation deltat, obtaining a position s0 of a leakage point through compensation of s 1-deltas, and feeding back the position of the leakage point to a scanning mechanism 3;
s7: the scanning mechanism 3 is positioned to the position of the leakage point and performs ink-jet marking in the process of returning to the original point;
s8: after the gas recovery is finished, the whole detection period is finished, and the step 1 is re-executed.
The original point returning process of the scanning mechanism 3 does not participate in leakage signal acquisition, and the time t4 is reduced by improving the original point returning speed of the mechanism so as to meet the time sequence requirement, wherein t4 is the time for the scanning mechanism 3 to return to the original point.
Specifically, as shown in fig. 2, the leak threshold should be determined by scanning the leak holes for leak rate under the same conditions.
Specifically, as shown in fig. 3, the time domain deviation Δt is determined by the response characteristic of the sensor, and can be compensated by testing the response characteristic of the sensor and mapping the response characteristic to the location domain.
In summary, compared with the conventional leak detection, the leak detection method and the system thereof suitable for high-speed scanning provided in this embodiment, after the scanning process is separated from the signal processing process, the zero-phase digital filter can be used to avoid the position deviation caused by the filtering phase delay, the peak searching algorithm is used to eliminate the position deviation related to the leak rate, after the leak marking process is separated from the scanning process, the scanning mechanism 3 can accurately position the target position for performing the inkjet marking, so as to reduce the leak marking error, and meanwhile, the method does not sacrifice the leak detection efficiency for improving the leak positioning marking precision.
The previous description of the embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (4)
1. The method adopts a leakage detection system which comprises a sensor module (1), a detected piece (2) filled with leakage gas, a scanning mechanism (3), a collecting card (4), a computer (5) and an inkjet marking device (6), wherein the sensor module (1) and the inkjet marking device (6) are both arranged on the scanning mechanism (3), the sensor module (1) and the scanning mechanism (3) are both electrically connected with the collecting card (4), and the scanning mechanism (3) and the collecting card (4) are both electrically connected with the computer (5);
the sensor module (1) is a gas sensitive sensor, the gas sensitive sensor consists of a sensitive element, an adapter plate and a signal conditioning module, the sensitive element is welded on the adapter plate, the adapter plate is connected with the signal conditioning module through a signal wire, and the signal conditioning module performs power amplification, operational amplification, filtering and other treatments on signals and then outputs the signals to the acquisition card (4) through a cable;
the scanning mechanism (3) comprises a driving motor, an encoder and a control system, the position information of the encoder can be output to the acquisition card (4), and the movement of the encoder is controlled by the computer (5);
the computer (5) is provided with signal processing and leakage point positioning software which is independently developed, the leakage point positioning software adopts zero-phase digital filtering pretreatment, and obtains the position of a leakage point through a peak searching algorithm and feeds back the position of the leakage point to a control system of the scanning mechanism (3);
the method comprises the following steps:
s1: placing a detected piece (2) filled with leakage gas on a detection table, and determining a time domain deviation delta t through a sensor characteristic test;
s2: replacing the detected piece;
s3: filling a certain pressure of leakage gas into the replaced detected piece, and starting signal acquisition at t6 before the mechanism scans, wherein t6 is not smaller than the width of a zero-phase FIR digital filtering window, and t6 is acquisition time in advance;
s4: the scanning mechanism (3) drives the sensor module (1) to scan along a suspicious region at a certain speed, and a leakage threshold value is determined;
s5: after the scanning is finished, starting to recycle gas, and delaying for a time t6 to stop collecting data;
s6: zero-phase filtering preprocessing is carried out on the signals, the displacement s1 of the position corresponding to the peak value is obtained through a peak searching algorithm, the corresponding displacement deltas is obtained through time domain deviation deltat, the position s0 of the leakage point is obtained through compensation of s 1-deltas, and the position of the leakage point is fed back to the scanning mechanism (3);
s7: the scanning mechanism (3) is positioned to the position of the leakage point and performs ink-jet marking in the process of returning to the original point;
s8: after the gas recovery is finished, the whole detection period is finished, and the step 1 is re-executed.
2. The leak detection method suitable for high-speed scanning according to claim 1, wherein the return-to-origin process of the scanning mechanism (3) does not participate in the collection of the leak signal, and the time t4 is reduced by increasing the return-to-origin speed of the mechanism to meet the time sequence requirement, and t4 is the return-to-origin time of the scanning mechanism (3).
3. A leak detection method for high speed scanning as defined in claim 2, wherein the leak threshold is determined by scanning leak holes at the same condition.
4. A leak detection method for high speed scanning as defined in claim 3, wherein the time domain deviation Δt is determined by the response characteristic of the sensor, and is compensated by testing the response characteristic of the sensor and mapping to the location domain.
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