CN116119006A - Methane detection system and method based on unmanned aerial vehicle-mounted laser methane detector - Google Patents

Abstract

The invention discloses a methane detection system and detection method based on an unmanned aerial vehicle-mounted laser methane detector, including a ground control terminal, an unmanned aerial vehicle, and a laser methane detection module; At the bottom of the man-machine, the methane detection module includes a laser and an alignment camera. The laser beam of the laser is arranged parallel to the optical axis of the alignment camera and is located on the same vertical plane. The laser is used to detect the methane concentration in the inspection area. The camera is used to take images of the inspection area; the system uses a drone equipped with a laser methane telemeter and a visible light pod on a dual-mounted platform to perform inspection tasks. There are cumbersome manual operations in pipeline inspections, pipeline leakage monitoring in complex environments, fragmentation and one-sided monitoring of inspection data, leakage caused by third-party occupancy or destruction, etc.

Description

Methane detection system and detection method based on unmanned aerial vehicle-mounted laser methane detector

technical field

The invention relates to the field of gas pipeline leakage detection systems, in particular to a methane detection system and detection method based on an unmanned aerial vehicle-mounted laser methane detector.

Background technique

With the continuous development of society, gas, a green and clean energy, has become more and more important in human life, and the gas industry has also ushered in opportunities for rapid development. However, the development of gas is accompanied by a huge crisis. Vicious accidents caused by sudden natural gas leakage occur frequently, causing heavy casualties and property losses, and severely damaging the ecological environment. The damage caused by the leakage of the gas pipeline network is large and the consequences are serious.

High-pressure gas pipelines have the characteristics of long distances, wide ranges, and complex landforms. Many locations are restricted by unfavorable factors such as harsh environments and inconvenient transportation. To a certain extent, it has brought difficulties to regular inspections of pipelines. Mainly rely on manual daily inspections. The staff are equipped with corresponding hand-held inspection equipment to conduct gas pipeline inspections by walking or driving. This method is greatly affected by climate, high equipment failure rate, and poor data signals in mountainous areas. The impact of the inspection results in scattered inspection data throughout the year, and the recording process of the inspection result data is time-consuming and labor-intensive. In many cases, the inspection data cannot fully reflect whether there is leakage and the specific circumstances of the leakage. At the same time, many hidden dangers cannot be discovered and dealt with in a timely manner. , leading to accidents.

With the continuous acceleration of pipeline construction, more and more pipelines need to pass through populated areas, which has led to frequent incidents of illegal occupation by third parties. In this case, due to the failure of normal inspection and maintenance of the pipeline, it is easy to corrode and perforate, resulting in leakage; at the same time, the occupation of pressure causes pipeline deformation and cracking events, resulting in gas leakage; after gas leakage, it cannot be repaired in time, resulting in secondary disasters, etc. The existing UAV high-pressure gas pipeline inspection scheme only carries methane monitoring equipment for inspection. A certain pitch angle will be generated when turning, etc., which will cause the methane detection equipment to leave the detection area, and at the same time make it difficult for the camera to take a clear picture of the pipeline environment information, and thus cannot determine whether there is a third-party occupation.

Contents of the invention

Aiming at the problems existing in the prior art, the present invention provides a methane detection system and detection method based on a drone-borne laser methane detector. Platform to perform inspection tasks. This system has a simple structure, reasonable design and high intelligence, which can effectively solve the cumbersome manual operations in existing pipeline inspections, pipeline leakage monitoring in complex environments, and one-sided inspection data fragmentation monitoring. Problems such as globalization, third-party occupation or destruction lead to leakage and other issues.

The present invention is achieved through the following technical solutions:

A methane detection system based on an unmanned aerial vehicle-mounted laser methane detector, comprising a ground control terminal, an unmanned aerial vehicle (1) and a laser methane detection module;

The laser methane detection module is arranged on the bottom of the unmanned aerial vehicle through an electric hanger, and the methane detection module includes a laser (21) and an alignment camera (22), a laser beam of the laser (21) and an alignment camera (22) The optical axis of is arranged in parallel, and is positioned at same vertical plane, and laser (21) is used for detecting the methane concentration of inspection area, aligns with camera and is used for taking the image of inspection area;

The drone is used to adjust the angle of the laser methane detection module according to the pitch angle, so that the laser methane detection module is always located in the current inspection area;

The laser methane detection module is connected to the ground control terminal through the UAV, and the ground control terminal is used to fuse the methane concentration information, flight path and video information according to time to generate the methane concentration change map of the detection area.

Preferably, the alignment camera is fixed at the bottom of the laser, and the alignment camera and the laser move synchronously.

Preferably, the adjustment range of the electric hanger is -10°-90°.

Preferably, the drone includes a drone body, and a power system module, a control module, a wireless communication module and a GPS positioning module arranged thereon;

The power system module is used to provide flight power for the UAV body;

GPS positioning module, used to provide real-time location information to the drone body;

The wireless communication module is used for data interaction between the UAV body and the ground control terminal;

The control module is used for adjusting the angle of the electric hanger according to the pitch angle of the drone.

A detection method of a methane detection system based on an unmanned laser methane detector, comprising the following steps:

Plan the flight path of the UAV according to the pipeline map, and set the detection angle of the laser methane detection module;

Obtain the pitch angle of the drone in real time. When the pitch angle exceeds the set threshold range of the set pitch angle, the control unit of the drone adjusts the detection angle of the laser methane detection module through the electric hanger according to the current pitch angle of the drone. , the adjusted laser methane detection module detects methane in the predetermined detection area, obtains a clear image of the detection area at the same time, and determines the occupancy of the detection area according to the image of the detection area;

The ground control terminal obtains the flight path, methane detection information and image information of the UAV in real time, and fuses the flight path, methane detection information and image information according to time to generate a methane concentration distribution map of the inspection area.

Preferably, the detection angle is the angle between the laser beam and the vertical plane, and the angle is 30°.

Preferably, the ground control terminal obtains the flight data of the UAV in real time, connects the position data of the UAV in real time to obtain the actual flight trajectory of the UAV, and compares the actual flight trajectory with the planned flight path Determine whether to deviate from the inspection route;

When the actual flight trajectory of the UAV deviates from the planned flight path, and when the yaw distance is greater than the set maximum yaw distance, the planned flight path is used to correct the UAV's trajectory.

Preferably, when the methane concentration in the detection area exceeds the initial set threshold, the ground control terminal outputs an alarm signal, and the automatic inspection mode of the UAV is modified to a manual inspection mode, and the staff of the ground control terminal is in the alarm area. Perform orbital flight detection;

After the detection of the alarm area is completed, the UAV is switched to the automatic inspection mode, and the UAV updates the navigation path with the set flight path as the target, and continues to perform the inspection task according to the updated navigation path.

Compared with the prior art, the present invention has the following beneficial technical effects:

The methane detection system based on the UAV-mounted laser methane detector provided by the present invention is equipped with a laser and an alignment camera on the bottom of the UAV through an electric hanger, and according to the pitch angle of the fusion of the UAV, combined with the electric hanger. The pitch angle of the laser and the alignment camera is adjusted so that the laser is always in the detection area, while ensuring the clarity of the image captured by the alignment camera. The laser is responsible for the detection of methane concentration. It uses a beam of laser light with a specific wavelength to pass through the measured space. If the There are methane molecules in the space, and the methane molecules absorb the laser to be detected. At the same time, the camera is aligned to solve the problem of poor visibility of the indicating laser under long-distance and high-brightness conditions, and it is impossible to clearly determine the detection point. According to the high-definition images taken by it Determine whether there is an occupation problem in the detection area. Secondly, the location information of the drone, the detection information of the laser, and the captured images are fused according to time to form a concentration change map that changes with the location, which is convenient for more quickly determining the specific location of the methane leak.

Description of drawings

Fig. 1 is the structural representation of the inspection drone of the present invention;

Fig. 2 is the structural block diagram of methane detection system of the present invention;

Fig. 3 is a flow chart of the detection method of the methane detection system of the present invention.

In the figure: 1. UAV; 2. Information collection module; 21 is a laser, 22 is an alignment camera, 23 is a high-definition camera, and 24 is an electric hanger.

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings, which are explanations rather than limitations of the present invention.

Referring to Fig. 1, a kind of methane detection system based on unmanned aerial vehicle-borne laser methane detector, comprises ground control terminal, unmanned aerial vehicle 1 and information collection module 2; Described unmanned aerial vehicle comprises unmanned aerial vehicle body, and is arranged on The power system module, flight control module, wireless communication module and GPS positioning module on the board.

The power system module is used to provide flight power for the UAV body; the GPS positioning module is used to provide real-time position information for the UAV body; the wireless communication module is used for real-time communication between the UAV body and the ground control terminal to realize wireless The transmission or reception of interactive data between the man-machine body and the control terminal; the airborne flight control module is used to realize automatic take-off and automatic landing according to the instructions of the control terminal, and perform inspection operations according to the specified route. All data between the ground station and the UAV is communicated through the wireless communication module. The ground control terminal receives the downlink data link sent from the UAV, and at the same time sends the uplink data link to the UAV.

The information collection module 2 includes a camera module and a methane detection module.

The camera module includes a high-definition camera 23, which is used to capture and collect target image information during the flight of the drone body;

The methane detection module includes a laser 21 and an alignment camera 22. The laser methane detection module is mainly composed of a laser, an alignment camera and an electric hanger. The laser is used for methane concentration detection, which uses a beam of laser light with a specific wavelength to pass through the measured space , if there are methane molecules in this space, the methane molecules will absorb the laser light and be detected. At the same time, the measured concentration data is transmitted to the ground control system in real time through the wireless communication module of the UAV system for real-time monitoring.

Aligning the camera is used to solve the problem of poor visibility of the indicating laser under long-distance and high-brightness conditions, and it is impossible to clearly determine the detection point. It is convenient for real-time observation and determination of the detection target. The display content is also transmitted to the UAV system through the wireless communication module. ground control system. The electric hanger is responsible for meeting the needs of multi-directional methane detection. Under the control of the remote control of the ground control system, the laser can be automatically adjusted from +10° to -90° to change the direction of laser emission.

The laser and the alignment camera are installed side by side under the electric hanger, and the electric hanger is connected to the UAV. The optical path of the alignment lens of the alignment camera is parallel to the detection laser light path of the laser, and the center of the picture captured by the lens is the alignment of the methane detector. Location.

Referring to Figures 2 and 3, the detection method of the methane detection system based on the unmanned laser methane detector provided by the present invention is described in detail below, including the following processes:

Step 1. Before the UAV performs the inspection mission, plan the flight path of the UAV through the ground control terminal according to the pipeline map that needs to be inspected; set the wavelength of the laser so that the wavelength is in the absorption band of natural gas; set the methane concentration Detection threshold; set the maximum yaw distance.

Step 2. Adjust the optical path angle of the laser through the electric hanger. In order to make the methane molecules diffused vertically upward appear on the detection optical path as much as possible, generally set the angle between the optical path direction of the laser and the horizontal flight direction of the drone to be 72° .

Step 3. After the UAV takes off, it will fly according to the set flight path. The ground control terminal will control the flight state of the UAV in real time. The flight state includes the flight speed, flight altitude, flight attitude and suspension of the UAV. stop time.

Step 4. The GPS positioning and navigation module is embedded in the UAV system, which can track the inspection trace in real time, accurately locate the detection point, and send the flight path of the UAV to the ground control terminal to form a map of the inspection trajectory. The flight path of the man-machine deviates from the path of the pipeline. When the yaw distance is greater than the set maximum yaw distance, the trajectory of the UAV is corrected with the pipeline path.

Connect the position data of the UAV in real time to obtain the actual flight trajectory of the UAV, and compare the actual flight trajectory with the designed flight trajectory to determine whether it deviates from the inspection route.

Step 5, during the inspection process of the UAV, the laser 21 transmits the methane concentration information detected on the flight path to the ground control terminal in real time, and simultaneously aligns the video information captured by the camera 22 and the high-definition camera and sends it to the ground control terminal. The data display unit of the terminal displays methane concentration information and video information, and integrates the methane concentration information, flight path, and video information according to time to form a concentration change map that changes with the location, which is convenient for more quickly determining the specific location of the methane leak.

Step 6. If the detected methane concentration exceeds the initial set threshold, the ground control terminal will output an alarm signal, and the automatic inspection mode of the drone will be changed to manual inspection mode, and the staff of the ground control terminal will be in the alarm area. Hover detection, or flying detection around, to obtain more information about the leakage area, after completing the detection of the alarm area, switch the UAV to the automatic inspection mode, and the UAV updates the navigation path with the set flight path as the target , and continue to execute the inspection task according to the updated navigation path.

Step 7. When the optical path emitted by the laser deviates, adjust the angle of the pod on the electric hanger 24 to realize the adjustment of the pitch angle of the optical path of the laser. The adjusted laser detects methane in the predetermined detection area and aligns it with the camera to obtain The detection area has a clear image, and the occupancy of the detection area is determined according to the image.

The specific adjustment method is as follows:

S7.1. Before the UAV performs the inspection task, set the optical path angle of the laser and the alignment camera, so that the alignment camera can obtain images of the shooting area.

In this embodiment, since the alignment camera is fixedly installed at the bottom of the laser, the optical path of the laser is set parallel to the optical axis of the alignment camera, and the two are synchronously adjusted by the electric hanger, and the pitch angle of the laser is 60°, that is, the optical path The horizontal angle with the drone is 60°.

S7.2. Obtain the pitch angle of the UAV fusion in real time. When the pitch angle is greater than the set threshold, the set angle of the laser light path is used as the starting angle, and the laser light path angle is adjusted according to the pitch angle. The adjustment value is Ipitch The opposite of the angle.

The electric hanger is responsible for the adjustment of the optical path angle of the laser. The adjustment plane is the plane where the pitch angle of the aircraft occurs, and the adjustment angle is +10°～-90°. Because the angle of movement of the electric pod only exists in the pitch angle plane, it is necessary to maintain a stable roll angle and a correct flight heading (guarantee the yaw angle) during the flight of the drone. The roll angle and yaw angle of the aircraft are mainly updated iteratively by the navigation module in the flight control. Through a certain extended Kalman filter algorithm for real-time solution.

During the inspection mission of the UAV, the rotorcraft will have a larger roll angle only when it makes a large-angle coordinated turn. However, the pipeline is generally straight and the turn is also a small angle. The roll angle can also be ignored here. For the impact on laser alignment, the position measured by the laser during the drone inspection is not directly below the aircraft, but an angle of about 30° directly below the front for laser emission detection, mainly considering the changes in the pitch angle of the aircraft. The problem of laser alignment is that the rotorcraft will produce a certain pitch angle when it starts and stops, accelerates and decelerates, turns, etc., and it is mainly caused by the head-up situation. If the drone’s head-up is too large, the laser cannot be aimed at the predetermined area, and errors may occur. detection, missed detection, etc., and at the same time cause the problem of unclear image shooting. The design of the electric turntable is to solve this problem.

When the aircraft is performing a flight mission, when the fused attitude angle exceeds the threshold of ±15°, adjust the angle of the electric hanger with 30° as the center, and the adjusted value is the opposite number of the pitch angle. The core control MCU of the UAV outputs a PWM to control the rotation of the steering gear of the electric hanger to realize the adjustment of the pitch angle of the laser. The ground station software is used for control. The ground operator can adjust the initial deflection angle through the real-time data returned by the high-definition camera, and the real-time angle rotation is output by the flight control, so as to solve the problem of accurate positioning of the aircraft and ensure that the measured area is as expected area.

The methane detection system based on the UAV-mounted laser methane detector provided by the present invention is equipped with a laser and an alignment camera on the bottom of the UAV through an electric hanger, and according to the pitch angle of the fusion of the UAV, combined with the electric hanger. The pitch angle of the laser and the alignment camera is adjusted so that the laser is always in the detection area, while ensuring the clarity of the image captured by the alignment camera. The laser is responsible for the detection of methane concentration. It uses a beam of laser light with a specific wavelength to pass through the measured space. If the There are methane molecules in the space, and the methane molecules absorb the laser to be detected. At the same time, the camera is aligned to solve the problem of poor visibility of the indicating laser under long-distance and high-brightness conditions, and it is impossible to clearly determine the detection point. According to the high-definition images taken by it Determine whether there is an occupation problem in the detection area. Secondly, the location information of the drone, the detection information of the laser, and the captured images are fused according to time to form a concentration change map that changes with the location, which is convenient for more quickly determining the specific location of the methane leak.

The above content is only to illustrate the technical ideas of the present invention, and cannot limit the protection scope of the present invention. Any changes made on the basis of the technical solutions according to the technical ideas proposed in the present invention shall fall within the scope of the claims of the present invention. within the scope of protection.

Claims (8)

1. The methane detection system based on the unmanned aerial vehicle-mounted laser methane detector is characterized by comprising a ground control terminal, an unmanned aerial vehicle (1) and a laser methane detection module;

the laser methane detection module is arranged at the bottom of the unmanned aerial vehicle through an electric hanging bracket, the methane detection module comprises a laser (21) and an alignment camera (22), the laser beams of the laser (21) and the optical axes of the alignment camera (22) are arranged in parallel and are positioned on the same vertical plane, the laser (21) is used for detecting the methane concentration of a patrol area, and the alignment camera is used for shooting images of the patrol area;

the unmanned aerial vehicle is used for adjusting the angle of the laser methane detection module according to the pitch angle, so that the laser methane detection module is always located in the current inspection area;

the laser methane detection module is connected with a ground control terminal through an unmanned aerial vehicle, and the ground control terminal is used for fusing methane concentration information, a flight path and video information according to time to generate a methane concentration change map of a detection area.

2. A methane detection system based on an unmanned airborne laser methane detector according to claim 1, wherein the alignment camera is fixed to the bottom of the laser and the alignment camera and the laser move synchronously.

3. A methane detection system based on an unmanned airborne laser methane detector according to claim 1, wherein the adjustment range of the electric hanger is-10 ° -90 °.

4. The methane detection system based on an unmanned aerial vehicle-mounted laser methane detector according to claim 1, wherein the unmanned aerial vehicle comprises an unmanned aerial vehicle body, and a power system module, a control module, a wireless communication module and a GPS positioning module which are arranged on the unmanned aerial vehicle body;

the power system module is used for providing flight power for the unmanned aerial vehicle body;

the GPS positioning module is used for providing real-time position information for the unmanned aerial vehicle body;

the wireless communication module is used for data interaction between the unmanned aerial vehicle body and the ground control terminal;

and the control module is used for adjusting the angle of the electric hanger according to the pitch angle of the unmanned aerial vehicle.

5. A method of detecting a methane detection system based on an unmanned on-board laser methane detector according to any one of claims 1 to 4, comprising the steps of:

planning a flight path of the unmanned aerial vehicle according to the pipeline map, and setting a detection angle of the laser methane detection module;

acquiring a pitch angle of the unmanned aerial vehicle in real time, adjusting a detection angle of a laser methane detection module by an electric hanging bracket according to the current pitch angle of the unmanned aerial vehicle when the pitch angle exceeds a set threshold range of the set pitch angle, performing methane detection on a preset detection area by the adjusted laser methane detection module, acquiring a clear image of the detection area, and determining the occupation condition of the detection area according to the image of the detection area;

the ground control terminal acquires the flight path, methane detection information and image information of the unmanned aerial vehicle in real time, and fuses the flight path, the methane detection information and the image information according to time to generate a methane concentration distribution map of the inspection area.

6. The method of claim 5, wherein the detection angle is an angle between the laser beam and the vertical plane, and the angle is 30 °.

7. The detection method of the methane detection system based on the unmanned aerial vehicle-mounted laser methane detector according to claim 5, wherein the ground control terminal acquires flight data of the unmanned aerial vehicle in real time, performs point connection on the position data of the unmanned aerial vehicle in real time to obtain an actual flight path of the unmanned aerial vehicle, and compares the actual flight path with a planned flight path to judge whether the actual flight path deviates from a patrol route;

when the actual flight path of the unmanned aerial vehicle and the planned flight path are yawed, and when the yawing distance is larger than the set maximum yawing distance, the planned flight path is used for correcting the flight path of the unmanned aerial vehicle.

8. The detection method of the methane detection system based on the unmanned aerial vehicle-mounted laser methane detector, according to claim 5, is characterized in that when the methane concentration of the detection area exceeds an initial set threshold value, the ground control terminal outputs an alarm signal, the automatic inspection mode of the unmanned aerial vehicle is modified to a manual inspection mode, and the staff of the ground control terminal performs surrounding flight detection in the alarm area;

after the detection of the alarm area is completed, the unmanned aerial vehicle is switched to an automatic inspection mode, the unmanned aerial vehicle updates the navigation path by taking the set flight path as a target, and the inspection task is continuously executed according to the updated navigation path.

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