CN-121978004-A - Tunnel harmful gas scanning type monitoring method and equipment

CN121978004ACN 121978004 ACN121978004 ACN 121978004ACN-121978004-A

Abstract

The invention provides a tunnel harmful gas scanning type monitoring method and equipment, and relates to the technical field of tunnel construction safety monitoring. The method comprises the following steps of S1, synchronously scanning at least two monitoring devices, recording direction angle data and gas concentration measurement values of each ray, obtaining tunnel boundary point cloud data, S2, calculating potential intersection points of rays from different devices in a tunnel space, screening effective intersection points, S3, constructing a three-dimensional network model of a tunnel surface through a Delaunay triangulation algorithm based on the tunnel boundary point cloud data, S4, grading the three-dimensional network model in a three-dimensional grid according to concentration values from low to high, assigning values to voxels through which effective laser rays pass, and reconstructing a three-dimensional concentration field, and S5, generating a tunnel harmful gas concentration distribution three-dimensional model. The method converts the path integral concentration data into accurate three-dimensional space distribution information, can accurately identify the three-dimensional coordinates of the gas escape sources, realizes the accurate positioning of the harmful gas escape sources, and effectively solves the problems of missed detection and misjudgment caused by positioning ambiguity.

Inventors

LI YOUGUI
ZHANG YONGGANG
SU PEIDONG
XIAO DIAN
TANG TAO
LEI MINGYU
Geng Bochuan
QIU PENG
YANG QING
LV FEI

Assignees

西南石油大学
川藏铁路技术创新促进会
川藏铁路技术创新中心有限公司

Dates

Publication Date: 20260505
Application Date: 20251218

Claims (9)

1. The scanning type monitoring method for the harmful gas in the tunnel is characterized by comprising the following steps of: s1, controlling monitoring equipment arranged at least two different positions in a tunnel to synchronously scan, emitting laser rays on a plurality of azimuth angles and pitch angles by each monitoring equipment, and synchronously recording direction angle data, pitch angle data, monitoring equipment numbers and concentration integral values of each laser ray; S2, screening laser rays with concentration integral value larger than 0 as effective laser rays; pairing the effective laser rays from different detection devices in pairs based on the direction angle data and the pitch angle data of the effective laser rays, and calculating potential intersection points of each pair of the effective laser rays in a space range defined by a tunnel design contour and initial concentration estimated values of the potential intersection points; s3, constructing a three-dimensional network model of the tunnel surface through a Delaunay triangulation algorithm based on the three-dimensional boundary point cloud data of the tunnel; S4, defining a three-dimensional grid in the three-dimensional network model, and carrying out grading treatment according to the concentration integral values of all the effective laser rays and the sequence from low to high on the basis of a gradual projection algorithm; S5, based on the three-dimensional gas concentration field, visualization is carried out through an isosurface, slicing or transparent body drawing mode, and a tunnel harmful gas concentration distribution three-dimensional model is generated.
2. The method for scanning and monitoring harmful gases in tunnels according to claim 1, wherein the number of the monitoring devices is two, and the monitoring devices are respectively arranged on two sides of the same end of the tunnels.
3. The method for monitoring the harmful gas in the tunnel according to claim 1, wherein the step S2 of calculating the potential intersection point comprises the steps of calculating three-dimensional direction vectors of a plurality of laser rays according to the position, azimuth angle and pitch angle parameters of the monitoring equipment to obtain the nearest intersection point of two laser rays from different monitoring equipment in space, and setting an intersection point tolerance threshold value, wherein the nearest intersection point is the potential intersection point which is smaller than or equal to the intersection point tolerance threshold value.
4. The method for scanning tunnel harmful gas monitoring according to claim 1, wherein calculating the initial concentration estimation value at the potential intersection point in step S2 includes calculating a mean value of the concentration integration values of each pair of laser rays as the initial concentration estimation value of the spatial point.
5. The method for monitoring tunnel harmful gas in a scanning manner according to claim 4, wherein the grading process in step S4 specifically includes dividing the gas concentration measurement values of all laser rays into a plurality of concentration levels on a logarithmic scale, sequentially processing rays in each concentration level from low to high according to the concentration levels, judging voxels through which each ray passes, if the voxels are not assigned, directly assigning a threshold value of the concentration level, if the voxels are assigned, comparing the threshold value of the current concentration level with the assigned value, and reassigning smaller values.
6. A tunnel harmful gas scanning monitoring method according to claim 5, wherein voxels not traversed by any laser radiation are filled in on the basis of the nearest neighbor interpolation algorithm by the concentration value of the neighboring assigned voxels.
7. A scanning type monitoring device using the scanning type monitoring method according to any one of claims 1 to 6, comprising a laser sensor module, a pitch angle adjusting component, a control component, an azimuth angle adjusting component and a bracket, wherein the azimuth angle adjusting component is installed on the bracket, the control component is installed on the azimuth angle adjusting component, the laser sensor module is installed on the control component through the pitch angle adjusting component, and the laser sensor module, the pitch angle adjusting component and the azimuth angle adjusting component are electrically connected with the control component.
8. The scanning monitoring device of claim 7, wherein the laser sensor module comprises a methane laser sensor, a carbon monoxide laser sensor, a carbon dioxide laser sensor, and a laser ranging sensor.
9. The scanning monitoring device of claim 7, further comprising a cleaning module including a drive device and a cleaning brush, the cleaning module being mounted on the laser sensor module and electrically connected to the control assembly.

Description

Tunnel harmful gas scanning type monitoring method and equipment Technical Field The invention relates to the technical field of tunnel construction safety monitoring, in particular to a tunnel harmful gas scanning type monitoring method and equipment. Background In the tunnel construction process, effective monitoring and controlling of the concentration of harmful gas are key links for guaranteeing construction safety. For example, controlling the methane (CH 4) concentration below a safe threshold prevents a fire accident, while strict monitoring of gases such as carbon monoxide (CO), carbon dioxide (CO 2) and the like avoids personnel poisoning risks. Therefore, accurate detection of the concentration of the harmful gas becomes a precondition for effective gas management. At present, the method for detecting harmful gas in the tunnel is mostly based on the coal mine gas monitoring technology. In the coal mine environment, the gas mainly originates from the coal seam, and the escape point is closely related to the position of the coal seam, so that the vast majority of risks can be covered by detecting the gas in the coal seam area. The monitoring means adopted correspondingly mainly comprise manual detection and fixed pumping automatic monitoring equipment. However, as tunnel engineering gradually advances to complicated strata such as western mountain areas, harmful gas escape phenomena occur in a large number of non-coal strata, the escape points of the harmful gas escape phenomena are distributed in a poor regularity and are random in positions, and the traditional method is difficult to cover the whole area. Once the detection is missed, serious accidents such as combustion, explosion and the like are extremely easy to occur. In the comprehensive view, the conventional harmful gas detection method has the following limitations that firstly, the manual detection has poor real-time performance and high cost, and is easy to form a detection dead angle due to the limitation of the detection range, and secondly, the fixed pumping automatic monitoring equipment can realize continuous detection, but the monitoring point position can not be flexibly adjusted, the potential risk area in the tunnel is difficult to cover completely, and the detection dead zone exists. In recent years, laser gas detection technology solves the problems of real-time and remote detection to a certain extent, but the method detects the average concentration or the whole concentration of the gas in a laser light path, and only the maximum concentration value and the approximate area thereof can be identified. Under the complex construction environment of the tunnel, the method can have larger deviation on the actual positioning of the gas escape source, even cause missed detection, and can not accurately reflect the gas space distribution condition. Disclosure of Invention The invention aims to provide a tunnel harmful gas scanning type monitoring method and equipment, which can solve the problems of the background technology aiming at the defects of the prior art. In order to solve the technical problems, the invention adopts the following technical scheme: a tunnel harmful gas scanning type monitoring method comprises the following steps: s1, controlling monitoring equipment arranged at least two different positions in a tunnel to synchronously scan, emitting laser rays on a plurality of azimuth angles and pitch angles by each monitoring equipment, and synchronously recording direction angle data, pitch angle data, monitoring equipment numbers and concentration integral values of each laser ray; S2, screening laser rays with concentration integral value larger than 0 as effective laser rays; pairing the effective laser rays from different detection devices in pairs based on the direction angle data and the pitch angle data of the effective laser rays, and calculating potential intersection points of each pair of the effective laser rays in a space range defined by a tunnel design contour and initial concentration estimated values of the potential intersection points; s3, constructing a three-dimensional network model of the tunnel surface through a Delaunay triangulation algorithm based on the three-dimensional boundary point cloud data of the tunnel; S4, defining a three-dimensional grid in the three-dimensional network model, and carrying out grading treatment according to the concentration integral values of all the effective laser rays and the sequence from low to high on the basis of a gradual projection algorithm; S5, based on the three-dimensional gas concentration field, visualization is carried out through an isosurface, slicing or transparent body drawing mode, and a tunnel harmful gas concentration distribution three-dimensional model is generated. Preferably, the number of the monitoring devices is two, and the monitoring devices are respectively arranged at two sides of the same end of the tunnel. Further, calculatin