Laser gas monitoring device based on micro-vibration mirror and scan combined with a cloud platform

Abstract

The utility model provides a kind of laser gas monitoring device based on microvibration mirror and scanning of combination of holder, comprising: holder, microvibration mirror laser telemetry module and power module;Microvibration mirror laser telemetry module includes laser emission optical module, laser receiving optical module, microvibration mirror, laser control unit, main control unit and signal output unit;Microvibration mirror is used to when receiving the voltage provided by power module controlled by main control unit, the detection laser deflected by laser emission optical module is reflected to target detection area after corresponding angle;Laser receiving optical module is used to receive the light signal reflected back by background reflection object after passing through target detection area, being absorbed by target gas, and after photoelectric conversion into electrical signal, it is transmitted to main control unit;Main control unit is used to transmit to signal output unit output after calculating the concentration information of target gas in target detection area.

Description

Technical Field

[0001] This utility model relates to the field of laser gas detection technology, specifically to a laser gas monitoring device based on a combination of micromirror and gimbal scanning. Background Technology

[0002] Traditional pan-tilt-zoom (PTZ) laser gas monitoring systems achieve 360-degree scanning detection by rotating the PTZ and driving the laser telemetry system. However, to achieve 360-degree scanning detection, the PTZ needs to be operated continuously. Since the PTZ uses mechanical transmission components, the rotating parts, transmission devices, and drive motors are very prone to damage during continuous rotation, which undoubtedly increases the system's maintenance costs.

[0003] Furthermore, to address the issues in existing technologies where angle control of the laser telemetry module using an electric pan-tilt unit leads to untimely measurement results and a reduction in the module's precision, Chinese invention patent application CN120102450A, published on June 6, 2025, discloses an all-angle laser gas telemetry device. This device includes a laser telemetry module and a reflector. The reflector is hinged to a reflector bracket, with the hinge axis between the bracket and the reflector extending horizontally. A pitch adjustment mechanism for driving the reflector's pitch adjustment is also provided between the bracket and the reflector. The reflector bracket is rotatably mounted on a housing, with the rotation axis of the bracket and housing extending vertically. The reflector facilitates the reflection of the emitted laser, allowing the laser to be reflected to different positions via mirror movement, facilitating measurements at various locations. However, the solution proposed in this patent application requires the design of a complex bracket and adjustment mechanism. Utility Model Content

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a laser gas monitoring device based on a combination of micro-mirror and gimbal scanning. This solves the problem that existing gimbal scanning laser gas monitoring systems require continuous operation of the gimbal to achieve 360-degree scanning detection. By simply setting up a micro-mirror and eliminating the need for complex structures, the frequency of gimbal scanning can be reduced, thus solving the problem of easy damage to the electric gimbal in the prior art.

[0005] This utility model provides a laser gas monitoring device based on the combined scanning of a micro-mirror and a gimbal, including: a gimbal, a micro-mirror laser telemetry module, and a power supply module for providing power voltage; The micro-mirror laser telemetry module is installed inside the micro-mirror laser gas telemetry chamber on the gimbal, and the gimbal drives the laser telemetry module to rotate under the control of the main control unit. The micromirror laser telemetry module includes a laser emitting optical module, a laser receiving optical module, a micromirror, a laser control unit, a main control unit, and a signal output unit; The micro-mirror is disposed after the laser emitting optical module and electrically connected to the power supply module. When it receives the voltage provided by the power supply module controlled by the main control unit, it deflects the detection laser emitted by the laser emitting optical module by a corresponding angle and reflects it to the target detection area. The laser receiving optical module is used to receive the backlight signal that passes through the target detection area, is absorbed by the target gas, and is reflected back by the background reflective object. After the backlight signal is photoelectrically converted into an electrical signal, the electrical signal is processed and transmitted to the main control unit. The main control unit is used to calculate the concentration information of the target gas in the target detection area based on the received electrical signal, and then transmit it to the signal output unit for output.

[0006] This invention integrates micromirror scanning technology with tunable laser absorption spectroscopy (TDLAS) to design a laser gas monitoring device based on a combination of micromirror and gimbal scanning. By rapidly deflecting the micromirror to change the direction of the detection laser, a wide-range gas remote sensing is achieved. When the gimbal scans a point, the device adjusts the deflection angles of the micromirror along the X and Y axes to achieve real-time monitoring of a large detection range. After scanning that point, the gimbal scans the next point, repeating this cycle to achieve 360-degree omnidirectional scanning. This reduces the frequency of gimbal scanning and lowers gimbal maintenance costs.

[0007] Based on the above, the micromirror described is an electrostatic MEMS micromirror. Electrostatic actuation relies on electrostatic force, i.e., the attractive force between two charged electrodes. Theoretically, this force requires only a very small current to generate and maintain (primarily to overcome capacitor charging and discharging and leakage current). It is particularly suitable for portable and implantable devices that are extremely sensitive to power consumption. Moreover, electrostatic force is inherently very fast; its response time is mainly limited by the inherent resonant frequency of the mechanical structure. Therefore, electrostatic MEMS micromirrors are suitable for high-frequency operation, easily achieving high-speed scanning at kilohertz (kHz) or even tens of thousands of hertz. Compared to electromagnetic actuation (which generates Joule heat) and electrothermal actuation (which itself requires heat generation), electrostatic actuation generates almost no heat during operation.

[0008] The laser emitting optical module includes a semiconductor laser, a targeting laser, a beam combiner, a collimator, a reflector, and a micro-mirror; the laser receiving optical module includes a receiving lens, a secondary focusing system, and a photodetector. The micro-mirror is placed at the edge of the receiving lens; The detection laser emitted by the semiconductor laser and the aiming laser emitted by the aiming laser are combined by the beam combiner and collimated by the collimator, and then reflected by the mirror onto the micro-mirror; the micro-mirror reflects the combined laser beam from the edge of the receiving lens to the target detection area; The reflected light signal, after being focused by the receiving lens and secondary focusing system, is received by the photodetector and converted into an electrical signal.

[0009] The MEMS micromirror is placed at the edge of the receiving lens, and the center of the receiving lens does not need to be drilled. The zero point of the MEMS micromirror is a horizontal position rotated counterclockwise by 45°. The laser collimator illuminates the surface of the reflector with a laser beam, which is then reflected back to the surface of the micromirror. When the MEMS micromirror is at its zero point, the laser beam is emitted parallel to the optical axis of the receiving lens. In this embodiment, the MEMS micromirror is placed at the edge of the receiving lens, and the center of the receiving lens does not need to be drilled, resulting in a simple structure and flexible design.

[0010] To perform visual monitoring of gas concentration, the laser gas monitoring device also includes a camera and a video fusion and transmission module. The camera is installed in the camera compartment on the pan-tilt unit and is used to capture video images of the target detection area when gas detection is performed on the target detection area. The video fusion and transmission module is connected to the signal output unit and the camera and is used to fuse the calculated gas concentration in the target detection area that exceeds the alarm threshold into the video image, and send the fused video image to an external monitoring device for visual monitoring of gas concentration.

[0011] This utility model has substantial features and progress compared to the prior art, specifically: 1. This utility model device can achieve 360-degree all-round scanning detection by rotating the pan-tilt unit four times, which solves the problems of high pan-tilt unit rotation frequency, easy damage to the pan-tilt unit, and high maintenance cost of the existing pan-tilt scanning laser gas monitoring system.

[0012] 2. The micromirror used in this utility model device is not only small in size and can be directly integrated into the optical path system, with a simple optical path structure, does not block effective light, and has a long detection distance; moreover, the scanning of the micromirror can be controlled simply by controlling the electrode voltage of the micromirror, with high synchronization of adjustment, high control precision, and a simple control system.

[0013] 3. This utility model device meets the needs of visual monitoring of gas concentration by using a micro-mirror scanning detection and a camera to capture video. Attached Figure Description

[0014] Figure 1This is a schematic diagram of the principle of this utility model.

[0015] Figure 2 This is a schematic diagram of the structure of the device of this utility model.

[0016] Figure 3 This is a schematic diagram of the micro-mirror laser gas telemetry chamber structure of the device of this utility model.

[0017] Figure 4 This is an exploded view of the micro-mirror laser telemetry module of the present invention.

[0018] Figure 5 This is the high-voltage power supply circuit that provides voltage to the micromirror in the power supply module of the device of this utility model.

[0019] In the diagram: 1 is the micro-mirror laser gas telemetry chamber, 2 is the gimbal, 3 is the device base, 4 is the camera chamber, 5 is the fill light, 6 is the external lead wire of the gimbal, 1-1 is the micro-mirror laser telemetry module, 1-2 is the semiconductor laser, 1-3 is the aiming laser, 1-4 is the power supply module, 1-5 is the video fusion and transmission module, 1-6 is the collimator, 1-7 is the reflector, 1-8 is the micro-mirror, 1-9 is the receiving lens, 1-10 is the filter, 1-11 is the secondary focusing lens, 1-12 is the photodetector, and 1-13 is the laser emission structure. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application. Example 1

[0021] like Figures 1-3 As shown, this embodiment proposes a laser gas monitoring device based on the combined scanning of a micro-mirror and a gimbal, including: a gimbal 2 mounted on the device base 3, a micro-mirror laser telemetry module 1-1, and a power supply module 1-4 for providing power supply voltage; The micro-mirror laser telemetry module 1-1 is installed inside the micro-mirror laser gas telemetry chamber 1 on the gimbal 2. The gimbal 2 drives the laser telemetry module to rotate under the control of the main control unit. The micromirror laser telemetry module 1-1 includes a laser emitting optical module, a laser receiving optical module, a micromirror, a laser control unit, a main control unit, and a signal output unit; The micro-mirror is disposed after the laser emitting optical module and electrically connected to the power supply module 1-4. When it receives the voltage provided by the power supply module 1-4 controlled by the main control unit, it deflects the detection laser emitted by the laser emitting optical module by a corresponding angle and reflects it to the target detection area. The laser receiving optical module is used to receive the backlight signal that passes through the target detection area, is absorbed by the target gas, and is reflected back by the background reflective object. After the backlight signal is photoelectrically converted into an electrical signal, the electrical signal is processed and transmitted to the main control unit. The main control unit is used to calculate the concentration information of the target gas in the target detection area based on the received electrical signal, and then transmit it to the signal output unit for output.

[0022] In this specific embodiment, the micromirror is an electrostatic MEMS micromirror with two axes, X and Y, and two electrodes on each axis. For this micromirror, controlling the voltage of the electrodes (electrodes X1, X2 and Y1, Y2) on the X and Y axes can achieve the reflection of the laser beam after deflection by an angle. Achieve X-axis deflection: The main control unit controls the power supply unit to fix the voltage values ​​of the two electrodes Y1 and Y2 of the micro mirror Y-axis, and provides corresponding voltage values ​​to the two electrodes X1 and X2 of the micro mirror X-axis, so that the laser beam can be deflected to the corresponding angle in the X-axis direction; Achieve Y-axis deflection: The main control unit controls the power supply unit to fix the voltage values ​​of the two electrodes X1 and X2 of the micromirror on the X-axis, and provides corresponding voltage values ​​to the two electrodes Y1 and Y2 of the micromirror on the Y-axis, so that the laser beam can be deflected to the corresponding angle in the Y-axis direction.

[0023] Specifically, in this embodiment, the laser emitting optical module includes a semiconductor laser 1-2, a targeting laser 1-3, a beam combiner, a collimator 1-6, a reflector 1-7, and a micro-mirror 1-8; the laser receiving optical module includes a receiving lens 1-9, a secondary focusing system (including a filter 1-10 and a secondary focusing lens 1-11), and a photodetector 1-12. The micro-mirrors 1-8 are placed at the edge of the receiving lens; The detection laser emitted by the semiconductor laser 1-2 and the aiming laser emitted by the aiming laser 1-3 are combined by the beam combiner and collimated by the collimator 1-6, and then reflected by the reflector 1-7 onto the micro-mirror 1-8; the micro-mirror 1-8 reflects the combined laser from the laser emission structure 1-13 to the target detection area. The reflected light signal, after being converged by the receiving lens 1-9 and the secondary focusing system, is received by the photodetector 1-12 and converted into an electrical signal.

[0024] In this embodiment, the photodetector 1-12 is a detector array responding to the detection laser. The receiving lens 1-9 is coated with an anti-reflection film for the measurement band to improve transmittance and increase the measurement distance. The secondary focusing system includes a secondary focusing lens 1-11 and a filter 1-10. The secondary focusing lens 1-11 is used to refocus the light converged by the receiving lens 1-9 for easy reception by the photodetector 1-12. The filter 1-10 is a bandpass filter that allows the measurement band to pass through. The aiming laser 1-3 is a visible light laser. After being combined with the detection laser by a beam combiner, it is collimated by the collimator 1-6 and reflected by the reflector 1-7 onto the micro-mirror 1-8, and then reflected by the micro-mirror 1-8 to the detection area to indicate the detection position of the detection laser.

[0025] In this embodiment, in order to perform visual monitoring of gas concentration, the laser gas monitoring device also includes a camera and video fusion and transmission modules 1-5; the camera is installed in the camera compartment 4 on the pan-tilt unit 2, and is used to capture video images of the target detection area when gas detection is performed in the target detection area; the video fusion and transmission modules 1-5 are connected to the signal output unit and the camera, and are used to fuse the calculated gas concentration in the target detection area that exceeds the alarm threshold into the video image, and send the fused video image to an external monitoring device for visual monitoring of gas concentration.

[0026] Preferably, in order to enable video image capture even in insufficient lighting conditions, the device in this embodiment is also equipped with a supplementary light 5.

[0027] The detection steps of the device in this embodiment are as follows: S1: After the device is powered on, the gimbal starts to rotate and the camera starts to take pictures. The main control unit in the micro-mirror laser telemetry module 1-1 controls the semiconductor laser 1-2 and the aiming laser 1-3 to emit light and controls the micro-mirror to rotate to the initial position.

[0028] S2: Once the gimbal has rotated to a certain position, the main control unit controls the power supply unit to supply power to the micromirror, controlling the deflection direction of the micromirror, i.e., the micromirror begins scanning the target detection area. The main control unit receives the electrical signal, calculates, and outputs the concentration information of the target gas in the target detection area.

[0029] S3: After scanning a point, control the pan-tilt unit to rotate to the next point and start scanning again. This cycle is repeated to achieve 360-degree all-around gas scanning and monitoring.

[0030] S4: When the target gas concentration in the detected target area exceeds the alarm threshold, the signal output unit in the micromirror laser telemetry module 1-1 sends the gas concentration data to the video fusion and transmission module 1-5. The video fusion and transmission module 1-5 fuses the gas concentration data with the video image and sends it to the external monitoring equipment for visual alarm of the gas concentration. The pan-tilt unit and micromirror continue monitoring along the original scanning path.

[0031] Typically, the corresponding areas of the image can be drawn in different colors according to the gas concentration, thus visually presenting the shape and size of the leaking gas cloud.

[0032] In this step, when the target gas concentration in the detected target area exceeds the alarm threshold, the pan-tilt unit can be kept at that position first, and then the micromirror can be controlled to perform a re-inspection scan according to the preset number of re-inspections. When the re-inspection confirms a gas leak, the signal output unit in the micromirror laser telemetry module 1-1 sends the gas concentration to the video fusion and transmission module 1-5. If the re-inspection confirms no gas leak, the micromirror laser telemetry module 1-1 discards the alarm and controls the micromirror to continue scanning along the original path. S5: When shutting down, control the pan-tilt unit and micromirror to return to zero before turning off the power to other parts of the device. Example 2

[0033] This embodiment takes methane gas monitoring as an example and provides a laser gas monitoring device based on a combination of micromirror and gimbal scanning.

[0034] In this embodiment, a DFB laser with a center wavelength of 1653.7 nm is selected as the light source; an InGaAs detector is selected as the photodetector, and an area array detector is selected for the area scanning detection range; the receiving lens is an aspherical lens coated with an anti-reflection film near 1653.7 nm, which can improve the transmittance of the receiving lens to the measurement laser and increase the telemetry distance; the filter is a bandpass filter near 1653.7 nm; the aiming lasers 1-3 are 532 nm green lasers; The electrostatic MEMS micromirror in this embodiment can be a micromirror from MirrorCare, with a mirror surface size of φ5mm, an angular resolution of ±0.005°, a deflection angle of ±8°, and a gold-plated reflector, achieving a reflectivity of over 95% for 1653.7 nm laser wavelengths. The main control unit can be an STM32H745 microcontroller. Specifically, in the design, it can be implemented using... Figure 5 The high-voltage power supply circuit shown provides voltage to the micromirror to deflect the laser beam.

[0035] The system provided in this application has been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A laser gas monitoring device based on a combination of micromirror and gimbal scanning, characterized in that, include: The gimbal, the micro-mirror laser telemetry module, and the power supply module for providing power voltage; The micro-mirror laser telemetry module is installed inside the micro-mirror laser gas telemetry chamber on the gimbal. The gimbal rotates the laser telemetry module under the control of the main control unit. The micromirror laser telemetry module includes a laser emitting optical module, a laser receiving optical module, a micromirror, a laser control unit, a main control unit, and a signal output unit; The micro-mirror is disposed after the laser emitting optical module and electrically connected to the power supply module. When it receives the voltage provided by the power supply module controlled by the main control unit, it deflects the detection laser emitted by the laser emitting optical module by a corresponding angle and reflects it to the target detection area. The laser receiving optical module is used to receive the backlight signal that passes through the target detection area, is absorbed by the target gas, and is reflected back by the background reflective object. After photoelectric conversion of the backlight signal into an electrical signal, the electrical signal is processed and transmitted to the main control unit. The main control unit is used to calculate the concentration information of the target gas in the target detection area based on the received electrical signal, and then transmit it to the signal output unit for output.

2. The laser gas monitoring device based on a combination of micromirror and gimbal scanning according to claim 1, characterized in that: The micromirror is an electrostatic MEMS micromirror.

3. The laser gas monitoring device based on a combination of micromirror and gimbal scanning according to claim 1 or 2, characterized in that: The laser emitting optical module includes a semiconductor laser, a targeting laser, a beam combiner, a collimator, a reflector, and a micro-mirror; the laser receiving optical module includes a receiving lens, a secondary focusing system, and a photodetector. The micro-mirror is placed at the edge of the receiving lens; The detection laser emitted by the semiconductor laser and the aiming laser emitted by the aiming laser are combined by the beam combiner and collimated by the collimator, and then reflected by the mirror onto the micro-mirror. The micro-mirror reflects the combined laser beam from the edge of the receiving lens to the target detection area; The reflected light signal, after being focused by the receiving lens and secondary focusing system, is received by the photodetector and converted into an electrical signal.

4. The laser gas monitoring device based on a combination of micromirror and gimbal scanning according to claim 1, characterized in that: It also includes cameras, video fusion and transmission modules; The camera is installed in the camera compartment of the pan-tilt unit and is used to capture video images of the target detection area when performing gas detection on the target detection area. The video fusion and transmission module is connected to the signal output unit and the camera, and is used to fuse the calculated gas concentration exceeding the alarm threshold in the target detection area into the video image, and send the fused video image to an external monitoring device for visual monitoring of gas concentration.

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