CN-119555635-B - Calibration method of gas leakage detection and quick tracing device

CN119555635BCN 119555635 BCN119555635 BCN 119555635BCN-119555635-B

Abstract

The invention discloses a calibration method of a gas leakage detection and quick tracing device, which belongs to the calibration of an included angle between an optical axis of a visible light imaging module and an optical spectrum detection module in the gas leakage detection and tracing device, and comprises the gas leakage detection and quick tracing device, when the included angle between two optical axes in the device is calibrated, the calibration method is that the coordinates of laser spots under the coordinate system of the visible light imaging module are restrained after an internal reference matrix and an external reference matrix are calibrated, the centroid of the spots is calculated finally, the optical axis of a tunable semiconductor laser absorption optical spectrum detection module is adjusted, and the adjustment and calibration are completed after the centroid accords with the limit; by the calibration method, the spatial misalignment of concentration data of the gas tunable semiconductor laser absorption spectrum detection module and the radiation value of the central point of the visible light imaging module can be reduced.

Inventors

LAI WENJIE
JIN GUIXIN
CHANG LEI
Gou Liuhui
CAI YONGWEI
LIU GUANGSHUAI

Assignees

成都汉威智感科技有限公司

Dates

Publication Date: 20260508
Application Date: 20241205

Claims (7)

1. The calibration method of the gas leakage detection and quick tracing device is characterized by comprising a gas leakage detection and quick tracing device and a wide spectrum camera, wherein the gas leakage detection and quick tracing device comprises a visible light imaging module, a gas tunable semiconductor laser absorption spectrum detection module, a signal synchronous acquisition module and a data processing unit; the visible light imaging module is used for imaging a leakage gas scene and providing a background and a basic coordinate system for positioning leakage; The gas tunable semiconductor laser absorption spectrum detection module is used for collecting the gas leakage concentration of the leakage point in the scene; The signal synchronous acquisition module is used for synchronizing data acquisition of the visible light imaging module and the gas tunable semiconductor laser absorption spectrum detection module; The data processing unit is used for realizing modeling of a gas leakage model, fitting of a concentration field and projection; an included angle exists between the optical axis of the visible light imaging module and the optical axis of the gas tunable semiconductor laser absorption spectrum detection module And an included angle of The following relationships are satisfied: ; ; Wherein, the As the upper limit of the angle of the lens, Is the distance between the optical center of the visible light imaging module and the optical center of the gas tunable semiconductor laser absorption spectrum detection module, Is the nominal working distance; the spectrum range of the wide spectrum camera covers the spectrum range of the gas tunable semiconductor laser absorption spectrum detection module, and the included angle is formed The calibration steps of (1) are as follows: s1-1, fixing a wide-spectrum camera and a visible light imaging module; step S1-2, calibrating an internal reference of a wide-spectrum camera to a visible light imaging module by using a target Sum-outer parameter matrix ; S1-3, placing a white board with good laser reflection on the gas tunable semiconductor laser absorption spectrum detection module, and calculating a white board plane in a coordinate system of the visible light imaging module according to four marking positions marked on four corners of the white board; S1-4, when the whiteboard plane is perpendicular to the optical axis of the visible light imaging module, determining that the coordinates of the laser spots of the gas tunable semiconductor laser absorption spectrum detection module under the coordinate system of the visible light imaging module are required to meet constraint; step S1-5, combining the internal parameters obtained in step S1-2 according to the constraint obtained in step S1-4 Sum-outer parameter matrix Calculating an image plane coordinate range of the constraint range projected into the wide spectrum camera; S1-6, imaging a laser spot of a gas tunable semiconductor laser absorption spectrum detection module by using a broad spectrum camera; and S1-7, calculating the mass center of the laser spot, adjusting the optical axis of the gas tunable semiconductor laser absorption spectrum detection module, and completing adjustment and calibration when the mass center of the laser spot accords with the limit of the step S1-5.
2. The method for calibrating a gas leakage detection and quick tracing apparatus according to claim 1, wherein in step S1-3, the distance between the wide spectrum camera 2 is set A whiteboard with good laser reflection to the gas tunable semiconductor laser absorption spectrum detection module is placed at the position of the whiteboard, four marking positions are marked on four corners of the whiteboard, and the plane of the whiteboard in the coordinate system of the visible light imaging module is calculated according to the four marking positions.
3. The method for calibrating a gas leakage detection and quick tracing apparatus according to claim 2, wherein in step S1-4, the method comprises the steps of Obtain a distance of 2 When the whiteboard plane is perpendicular to the optical axis of the visible light imaging module, the laser spot of the gas tunable semiconductor laser absorption spectrum detection module is at the coordinate of the coordinate system of the visible light imaging module ) The following constraints need to be met: ; 。
4. The method for calibrating a gas leakage detecting and quick tracing device according to claim 1, wherein in step S1-5, the internal parameters obtained in step 1-2 are combined according to the constraints obtained in step 1-4 Sum-outer parameter matrix The image plane coordinate range of the constraint range projected into the wide spectrum camera is calculated, and a specific calculation formula is as follows: ; 。
5. The method for calibrating a gas leakage detection and quick tracing device according to claim 1, wherein the frame rate of the visible light imaging module in the gas leakage detection and quick tracing device is the same And sampling frequency of gas tunable semiconductor laser absorption spectrum detection module The following conditions are satisfied: ; ; ; ; Wherein, the As the minimum value of the frame rate of the image, At the minimum value of the TDLAS sample rate, The gas leakage detection and quick tracing device is used for detecting the gas leakage and quickly tracing the movement angular speed of the device; take 1 as an empirical value.
6. The method for calibrating a gas leakage detection and rapid tracing apparatus according to claim 1, wherein the distance between the optical center of the visible light imaging module and the optical center of the gas tunable semiconductor laser absorption spectrum detection module is set when the visible light imaging module and the gas tunable semiconductor laser absorption spectrum detection module are installed in the gas leakage detection and rapid tracing apparatus The following conditions are satisfied: ; Wherein, the For the laser beam waist width, Is the laser rayleigh distance; For the empirical value, 10 was taken.
7. The method for calibrating a gas leakage detection and rapid tracing apparatus according to claim 1, wherein the deviation between the time when the signal synchronization acquisition module acquires the image and the time when the gas tunable semiconductor laser absorption spectrum detection module acquires the concentration is controlled within a range when the signal synchronization acquisition module acquires the synchronization data In, and the Expressed as: ; Wherein, the The gas leakage detection and quick tracing device is used for detecting the gas leakage and quickly tracing the movement angular speed of the device; take 1 as an empirical value.

Description

Calibration method of gas leakage detection and quick tracing device Technical Field The invention belongs to the technical field of gas detection, relates to detection and tracing of gas leakage, and particularly relates to a calibration method of a gas leakage detection and quick tracing device. Background The gas leakage detection technology has wide and important application in the fields of atmospheric pollution control, petrochemical industry, industrial process monitoring and the like. For example, in industries such as petrochemical industry, a large number of methane gas storage or transportation devices with complex structures exist, and effective monitoring of leakage conditions of the devices is an important precondition for ensuring safe production. For gas leakage, contact type leakage detecting equipment is widely adopted at present, and a sensor of the equipment needs to be in contact with detection target gas to find leakage. However, some leakage points may be leaking, but most potential leakage points do not leak yet, so that an operator must personally check and detect each potential leakage point, which is very inefficient and may cause harm to the health and safety of an inspector. In addition, the traditional gas leakage detection technology can only realize single-point concentration measurement, and the gas leakage infrared imaging technology developed for methane gas leakage detection has the advantages of large-scale monitoring and quick tracing by imaging leakage gas through utilizing an infrared focal plane detector, but cannot realize quantitative measurement of leakage concentration, and cannot provide accurate situation research and judgment basis for subsequent accident assessment and remedy treatment. The invention patent application with the application number 202010443190X discloses an infrared imaging and concentration detecting device and method for methane gas leakage, the device comprises an infrared thermal imager and a laser methane detecting module, the infrared thermal imager is used for carrying out infrared imaging on a required monitoring area to find out methane gas leakage points, the laser methane detecting module is used for aligning according to the leakage points found by infrared imaging and measuring methane concentration, the laser methane detecting module is embedded in the infrared thermal imager, and the laser beam emitting direction of the laser methane detecting module is adjusted to be consistent with the optical axis direction of the infrared thermal imager, and data interaction is realized by mutual communication between the laser methane detecting module and the laser methane detecting module. The infrared thermal imager can detect a large-area window to judge whether natural gas leaks in the window, the laser methane detection module is used for carrying out remote non-contact measurement on a methane leakage point and obtaining accurate methane gas concentration information, the infrared thermal imaging technology for methane gas leakage detection is combined with the laser methane detection technology, meanwhile, the non-contact large-area rapid search of methane leakage point and the quantitative detection of methane gas concentration are realized, and the comprehensive detection which is more efficient and accurate and quantitative than that of the existing single detection device is realized. In the above-mentioned patent application of infrared imaging and concentration detection device and method, it is realized that the methane leakage point and methane gas concentration are quantitatively detected. However, firstly, the single-point concentration measurement can be realized only as in the traditional gas leakage detection technology, and the concentration field step-by-step cannot be obtained, secondly, the traditional gas leakage tracing mostly uses an infrared sensor to carry out gas imaging, but the infrared sensor has higher price and is not beneficial to popularization and application, and thirdly, the traditional visible light image only provides a site evidence collecting function and does not have the capability of rapid tracing. Therefore, in order to reduce cost and promote application, how to use visible light imaging for tracing gas leakage and realizing rapid tracing of gas leakage is important, and it is necessary to provide a device and a method for detecting and rapidly tracing gas leakage based on visible light imaging and a method for calibrating an included angle of an optical axis in the tracing device. Disclosure of Invention The invention aims to provide a calibration method of a gas leakage detection and quick tracing device, which is used for forming an included angle between an optical axis of a visible light imaging module and an optical axis of a gas tunable semiconductor laser absorption spectrum detection moduleAnd (5) calibrating. The invention adopts the following technical scheme for realizing the purp