TDLAS-Based 3D Gas Detection Device for Measuring Specific Gases in the Surrounding Environment Mounted on a Mobile Robot

Abstract

A TDLAS-based 3D gas detection device for measuring a specific gas in an surrounding environment, mounted on a mobile robot according to the present invention, comprises a mobile robot platform and a TDLAS-based gas detection sensor mounted on the mobile robot platform and coupled to the mobile robot platform so as to be rotatable to a measurement target within a predetermined range of angles, and for measuring a gas concentration at a specific absorption wavelength through laser irradiation in a measurement direction, wherein the gas detection sensor specifies the intersection point of the laser irradiation paths where the gas detected at different points is detected as the gas detection point based on whether gas is detected on a plurality of laser irradiation paths measured at an arbitrary point and whether gas is detected on a plurality of laser irradiation paths measured at another arbitrary point.

Description

Technology Field

[0001] The present invention relates to a gas detection device mounted on a mobile robot for measuring gases present in the surrounding environment. Specifically, it relates to a gas detection device that detects gas concentrations at multiple points using the TDLAS (Tunable Diode Laser Absorption Spectroscopy) method and generates a three-dimensional gas distribution map based on this. Background Technology

[0002] Traditionally, various sensors and devices have been used in industrial sites, indoor environmental monitoring, and research facilities to determine gas leaks or detect hazardous gases. A diverse range of gas measurement technologies exists, including patented chemical sensors, infrared sensors, and optical sensors.

[0003] Conventional gas detection systems had limitations in that they measured only the gas concentration at a single point from a fixed location. Furthermore, even when using mobile sensors, it was common practice to measure only two-dimensional distributions. There is a need for the development of technology to accurately measure and visualize gas distribution in three-dimensional space. The problem to be solved

[0004] The present invention aims to provide a gas detection device capable of creating a three-dimensional gas detection map of space through a detection sensor mounted on a mobile robot, moving away from a method of measuring gas detection at only a single point.

[0005] In addition, the present invention aims to provide a three-dimensional gas detection device capable of specifying a specific gas detection location in space. means of solving the problem

[0006] According to one embodiment of the present invention for achieving the above objective, a TDLAS-based three-dimensional gas detection device for measuring a specific gas in an surrounding environment mounted on a mobile robot comprises: a mobile robot platform; and a TDLAS-based gas detection sensor mounted on the mobile robot platform, coupled to the mobile robot platform so as to be rotatable as a measurement target within a predetermined range of angles, and capable of measuring a gas concentration at a specific absorption wavelength through laser irradiation in a measurement direction; wherein the gas detection sensor specifies the intersection point of the laser irradiation paths where the gas detected at different points is detected as the gas detection point, based on whether gas is detected on a plurality of laser irradiation paths measured at an arbitrary point and whether gas is detected on a plurality of laser irradiation paths measured at another arbitrary point.

[0007] In one embodiment, the mobile robot platform includes a position recognition unit for recognizing the movement position of the mobile robot platform at a location to be detected and the direction of the mobile robot platform, and the gas detection sensor confirms the measurement position of the detection sensor based on the position of the mobile robot platform transmitted from the position recognition unit.

[0008] In one embodiment, the position recognition unit recognizes the movement position and direction based on the relative position with the position recognition indicators installed at multiple locations of the location to be detected.

[0009] In one embodiment, the mobile robot platform determines the direction of movement and the position of movement of the mobile robot platform based on a pre-stored detection map corresponding to the location to be detected and relative position information with the position recognition indicator.

[0010] In another embodiment, the mobile robot platform determines an arbitrary direction of movement and a position of movement, creates and updates a detection map of the location to be detected at the corresponding point, and determines the direction of movement and the position of the mobile robot platform based on the created detection map and relative position information with the position recognition indicator.

[0011] In one embodiment, the gas detection sensor obtains a first gas concentration measurement result through laser irradiation in each measurement direction at a predetermined angle according to a first rotation direction in the horizontal direction at any point and a second gas concentration measurement result through laser irradiation in each measurement direction at a predetermined angle according to a second rotation direction in the vertical direction at any point, and calculates the intersection point of each measurement direction where gas is detected based on the first gas concentration measurement result and the second gas concentration measurement result at a plurality of points different from the arbitrary point, thereby obtaining a three-dimensional gas detection result at the location to be detected.

[0012] In another embodiment, the gas detection sensor obtains gas concentration measurement results by laser irradiating each measurement direction at a predetermined angle according to the horizontal rotation direction at any one point, and calculates the intersection points of each measurement direction where gas is detected based on the gas concentration measurement results according to each measurement direction at a predetermined angle at the arbitrary one point and a plurality of other points, thereby obtaining gas detection results at the location to be detected.

[0013] In one embodiment, the gas detection sensor stores the location where gas is detected at the gas detection target location, creates a gas distribution map of the gas detection target location based on this, and selects the previously stored gas detection location as a priority monitoring target.

[0014] In one embodiment, the gas detection sensor adjusts the angle for laser irradiation at any point randomly or sequentially in a predetermined direction. Effects of the invention

[0015] The TDLAS-based 3D gas detection device according to the present invention attempts to detect gas from multiple angles using a TDLAS-based gas detection sensor mounted on a mobile robot, recognizes gas detection at a specific point and a specific angle based on the gas concentration detected in a specific direction, and recognizes gas detection at another specific point and another specific angle to identify the intersection point as a gas detection point, thereby having the effect of creating a three-dimensional gas detection map of space.

[0016] In addition, the TDLAS-based 3D gas detection device according to the present invention has the effect of creating a 3D gas detection map in addition to a 2D gas detection map by rotating the gas detection sensor in a horizontal direction and irradiating a laser at multiple angles, and also rotating it in a vertical direction and irradiating a laser at multiple angles.

[0017] In addition, the TDLAS-based 3D gas detection device according to the present invention not only creates a movement map of the detection target space through position recognition of a mobile robot platform, but also displays previously detected gas detection locations within the area for priority management, thereby enabling the location to be inspected first when gas is detected in the future. Brief explanation of the drawing

[0019] FIG. 1 shows a schematic configuration of a TDLAS-based three-dimensional gas detection device according to one embodiment of the present invention. Figure 2 is a schematic diagram briefly showing the internal configuration of a TDLAS-based 3D gas detection device. Figure 3 shows the operating principle of a TDLAS-based gas detection sensor. FIG. 4 schematically illustrates a method for specifying a gas detection point of a gas detection sensor according to the present invention. Figure 5 shows the detection process of a TDLAS-based three-dimensional gas detection device according to the present invention. Specific details for implementing the invention

[0020] Preferred embodiments according to the present invention will be described in detail below with reference to the attached drawings. Prior to this, terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, and should be interpreted in a meaning and concept consistent with the technical spirit of the present invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention.

[0021] Therefore, the embodiments described in this specification and the configurations illustrated in the drawings are merely the most preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention; thus, it should be understood that various equivalents and modifications that can replace them may exist at the time of filing this application.

[0022] FIG. 1 shows a schematic configuration of a TDLAS-based three-dimensional gas detection device according to one embodiment of the present invention.

[0023] Referring to FIG. 1, the TDLAS-based three-dimensional gas detection device (100) according to the present invention includes a mobile robot platform (110) and a TDLAS-based gas detection sensor (120).

[0024] The mobile robot platform (110) is equipped with a driving motor, a control unit, a power supply unit, a communication module, etc., and can move autonomously or semi-autonomously indoors and outdoors. Additionally, the mobile robot platform (110) may be additionally equipped with an obstacle detection and avoidance system.

[0025] Additionally, the mobile robot platform (110) may be provided with a vibration reduction device or support to stably operate the TDLAS-based gas detection sensor (120).

[0026] For example, the mobile robot platform (110) may include a Simultaneous Localization and Mapping (SLAM) system, an Inertial Measurement Unit (IMU), and an encoder system.

[0027] In addition, the mobile robot platform (110) is equipped with a sensor module on a four-wheel drive autonomous robot. The robot may be configured to enable position recognition and mapping by including a LiDAR sensor that performs SLAM, an IMU, GPS, etc.

[0028] Figure 2 is a schematic diagram briefly showing the internal configuration of a TDLAS-based 3D gas detection device.

[0029] Referring to FIG. 2, the mobile robot platform (110) may include a location recognition unit (110) and a map storage unit (112).

[0030] The position recognition unit (111) functions to recognize the movement position and the direction of the mobile robot platform at the location to be detected by the mobile robot platform. Through the position of the mobile robot platform provided by the position recognition unit (111), the gas detection sensor (120) is able to confirm the measurement position measured by the detection sensor.

[0031] In addition, the location recognition unit (111) can recognize the movement position and direction based on the relative position with the location recognition indicator installed at multiple locations of the location to be detected. Through this, the mobile robot platform (110) can determine the movement direction and movement position of the mobile robot platform based on the detection map stored in the map storage unit (112) corresponding to the location to be detected and the relative position information with the location recognition indicator. In another example, the mobile robot platform (110) can determine an arbitrary movement direction and movement position without including the map information of the location to be detected stored in advance, create and update the detection map of the location to be detected at the corresponding point, and determine the movement direction and movement position of the mobile robot platform based on the detection map created and stored in the map storage unit (112) and the relative position information with the location recognition indicator.

[0032] Meanwhile, the TDLAS-based gas detection sensor (120) is mounted on a mobile robot platform (110), combined with the mobile robot platform so that it can be rotated to a measurement target within a predetermined range of angles, and functions to measure gas concentration at a specific absorption wavelength through laser irradiation in the measurement direction.

[0033] The TDLAS-based gas detection sensor (120) is, for example, a diode laser assembly using a laser light source and forms an optical path including a gas cell, radius, or lens. Then, the concentration is calculated by measuring the absorbance of the target gas through a specific absorption spectrum, i.e., a laser wavelength. The TDLAS-based gas detection sensor (120) may utilize optical fibers, splitters, rotary scanning mirrors, or multiple laser elements through multi-channel, i.e., multi-point measurement. For example, the TDLAS-based gas detection sensor (120) may include a tunable diode laser light source, a photodetector and signal processing unit, a multipath optical system, and a high-speed optical scanning system, and additionally may include a MEMS mirror-based beam steering device and a 3-axis linear motor-based optical system driving mechanism.

[0034] Tunable diode laser absorption spectroscopy (TDLAS) technology measures the concentrations of impurities in gas processes online in real time, from sub-ppm levels to percentage levels. This technology has the advantage of being applicable to a wide range of applications for measuring moisture (H₂O), carbon dioxide (CO₂), hydrogen sulfide (H₂S), ammonia (NH₃), acetylene (C₂H₂), and other compounds.

[0035] Figure 3 shows the operating principle of a TDLAS-based gas detection sensor.

[0036] In the embodiment illustrated in FIG. 3, in one embodiment, the TDLAS-based gas detection sensor (120) receives factory gas from a sampling probe into the sample cell of the gas detection sensor, and a variable diode laser emits near-infrared (NIR) and visible light that can be absorbed by the object to be analyzed. The laser light enters the sample cell, passes through the gas, is reflected by one or more mirrors, and is finally received by a photodiode detector.

[0037] The shielding glass serves to separate the laser and detector from the process gas. This component prevents contact between the gas sample and critical components within the gas detection sensor. According to the Beer-Lambert law, molecules in the gas absorb or reduce the intensity of light in direct proportion to the concentration of the gas being analyzed.

[0038] The gas detection sensor measures the intensity of the transmitted laser and the laser wavelength received by the gas detection sensor, as shown in Graphs 1 and 2 of Fig. 3. In Graph 1, the absorbed wavelength is not visible, while in Graph 2, the absorbed wavelength is visible in a form where a specific section sags downward. To improve the detection sensitivity of this absorbed wavelength, a second harmonic (2f signal) method can be used for wavelength modulation spectroscopy (WMS).

[0039] Graph 3 in Fig. 3 represents the second harmonic, which uses an amplifier to improve detection sensitivity and remove noise, thereby significantly improving the signal-to-noise ratio. The second harmonic signal can be processed through an algorithm to calculate the concentration of the analyte.

[0040] In one embodiment, a TDLAS-based gas detection sensor (120) uses a semiconductor laser diode to measure a spectrum that absorbs methane (CH4), etc., at a specific wavelength (e.g., 1,650 nm). It calculates a target gas concentration while scanning the laser output and frequency.

[0041] The TDLAS-based gas detection sensor (120) is capable of detecting multiple types of gases. By additionally arranging multiple laser elements corresponding to gases with different absorption spectra, such as methane, carbon dioxide, and carbon monoxide, it is possible to measure multiple types of gases simultaneously. Furthermore, the TDLAS-based gas detection sensor (120) is applicable to outdoor environments. Through hardware design that enables robot operation in harsh outdoor conditions and waterproof / dustproof design, it can also be utilized for monitoring gas leaks in industrial complexes and areas outside chemical plants.

[0042] And the TDLAS-based gas detection sensor (120) can be designed to include an automatic alarm system so that when a concentration above a certain level is detected, the robot automatically generates an alarm sound or visual alarm, or immediately transmits data to a control server to respond.

[0043] Meanwhile, the TDLAS-based gas detection sensor (120) according to the present invention is capable of multi-point measurement, that is, measurement in multiple directions or angles. For example, the TDLAS-based gas detection sensor (120) acquires data from multiple angles in the up, down, left, and right directions through a rotating mirror or a plurality of laser elements mounted on the sensor module. A separate collection channel is provided for each measurement beam to read absorbance data in real time. Then, the absorbance spectrum is analyzed in a processor to calculate the gas concentration (ppm or %). At the same time, it is matched with the position (3D coordinates) of the robot.

[0044] In addition, the TDLAS-based gas detection sensor (120) according to the present invention can generate a 3D gas distribution map using the detected gas locations. Concentration data collected from multiple points is processed using spatial interpolation or a machine learning-based spatial prediction technique to finally generate a 3D distribution map. The map can be transmitted to a local (robot-mounted PC) or remote server for visualization.

[0045] The acquisition of the three-dimensional gas detection result of the present invention will be explained in detail with reference to FIG. 4.

[0046] FIG. 4 schematically illustrates a method for specifying a gas detection point of a gas detection sensor according to the present invention.

[0047] Figure 5 shows the detection process of a TDLAS-based three-dimensional gas detection device according to the present invention.

[0048] Referring to FIGS. 4 and 5, the gas detection sensor (120) can identify the intersection point of the laser irradiation paths where the gas detected at different points is detected as the gas detection point, based on whether gas is detected on a plurality of laser irradiation paths measured at any one point and whether gas is detected on a plurality of laser irradiation paths measured at another arbitrary point.

[0049] For example, when the mobile robot platform (110) is positioned at the first measurement location (S11), information regarding the point and the direction the mobile robot platform is facing is transmitted to the gas detection device (120), and the gas detection device (120) rotates in multiple directions and irradiates lasers at multiple angles, i.e., multiple directions, to check for gas detection in the corresponding direction (S12). Then, it checks whether gas is detected for each direction (S13).

[0050] At this time, the gas detection device (120) may randomly adjust the angle for laser irradiation at any point, or may sequentially adjust the angle in a specific direction.

[0051] Then, when the mobile robot platform (110) is positioned at the second measurement location (S14), information regarding the point and the direction the mobile robot platform is facing is transmitted to the gas detection device (120), and the gas detection device (120) rotates in various directions and irradiates lasers at various angles, i.e., in various directions, to check for gas detection in the corresponding direction (S15). Then, it checks whether gas is detected for each direction (S16).

[0052] Then, the direction in which gas is detected for each direction is crossed at two points or multiple points, and the crossed point is designated as the gas detection location (S17).

[0053] In one embodiment, the gas detection sensor (120) obtains a first gas concentration measurement result through laser irradiation in each measurement direction at a predetermined angle according to a first rotation direction in the horizontal direction at any point and a second gas concentration measurement result through laser irradiation in each measurement direction at a predetermined angle according to a second rotation direction in the vertical direction at any point, and calculates the intersection point of each measurement direction where gas is detected based on the first gas concentration measurement result and the second gas concentration measurement result at a plurality of points different from the arbitrary point, thereby obtaining a three-dimensional gas detection result at the location to be detected.

[0054] In addition, in another embodiment, the gas detection sensor (120) obtains a gas concentration measurement result by laser irradiating each measurement direction at a predetermined angle according to the rotational direction in the horizontal direction at any one point, and calculates the intersection point of each measurement direction where gas is detected based on the gas concentration measurement result according to each measurement direction at a predetermined angle at the arbitrary one point and a plurality of other points, thereby obtaining a gas detection result at the location to be detected. This process may be performed through the gas detection specific part (121) of the gas detection sensor (120).

[0055] In addition, the gas detection sensor (120) according to the present invention stores the location where gas is detected at the gas detection target location, creates a gas distribution map of the gas detection target location based on this (S17), and can select the previously stored gas detection location as a priority monitoring target. That is, by creating a 3D or 2D gas distribution map, it is possible to check the history of gas generation in a specific area and take measures to inspect that area first when gas is detected in the future, or to conduct multiple inspections from various angles at multiple points. The created gas distribution map may be stored in the map storage unit (112) of FIG. 2 or may be stored in a separate gas detection result map storage unit.

[0056] At this time, the gas detection sensor (120) generates a 3D gas distribution map of the location to be detected using a 3D gas distribution modeling algorithm. For example, the algorithm can be processed through a 3D mapping algorithm, interpolation, machine learning-based correction, etc.

[0057] A method for generating a 3D gas distribution map based on these 3D gas detection results can collect measurement data from multi-point TDLAS-based gas detection sensors while a mobile robot platform moves, match the collected data with spatial coordinates—that is, the robot position—and then visualize it using 3D volume rendering or a mesh method. In addition, it may be possible to generate time-series 3D data by tracking changes in gas concentration over time.

[0058] Thus, the TDLAS-based 3D gas detection device according to the present invention attempts to detect gas from multiple angles using a TDLAS-based gas detection sensor mounted on a mobile robot, recognizes gas detection at a specific point and a specific angle based on the gas concentration detected in a specific direction, and recognizes gas detection at another specific point and another specific angle to identify the intersection point as a gas detection point, thereby having the effect of creating a three-dimensional gas detection map of space.

[0059] In addition, the TDLAS-based 3D gas detection device according to the present invention has the effect of creating a 3D gas detection map in addition to a 2D gas detection map by rotating the gas detection sensor in a horizontal direction and irradiating a laser at multiple angles, and also rotating it in a vertical direction and irradiating a laser at multiple angles.

[0060] In addition, the TDLAS-based 3D gas detection device according to the present invention not only creates a movement map of the detection target space through position recognition of a mobile robot platform, but also displays previously detected gas detection locations within the area for priority management, thereby enabling the location to be inspected first when gas is detected in the future.

[0061] As described above, although the present invention has been explained by limited embodiments and drawings, the present invention is not limited thereto, and it is obvious that various modifications and variations are possible within the scope of the technical spirit of the present invention and the equivalent scope of the claims described below by those skilled in the art to which the present invention belongs. Explanation of the symbols

[0062] 100: TDLAS-based 3D gas detection device 110: Mobile Robot Platform 120: Gas detection sensor 111: Location recognition unit 112: Map Storage 121: Gas detection specific part

Claims

Claim 1 A TDLAS-based 3D gas detection device for measuring specific gases in a surrounding environment mounted on a mobile robot, comprising: a mobile robot platform; A TDLAS-based gas detection sensor is mounted on the mobile robot platform and coupled to the mobile robot platform so as to be rotatable as a measurement target within a predetermined range of angles, and is configured to measure gas concentration at a specific absorption wavelength through laser irradiation in a measurement direction; wherein the gas detection sensor specifies the intersection point of the laser irradiation paths where gas is detected at different points as the gas detection point based on whether gas is detected on a plurality of laser irradiation paths measured at an arbitrary point and whether gas is detected on a plurality of laser irradiation paths measured at another arbitrary point; wherein the gas detection sensor obtains a first gas concentration measurement result through laser irradiation in each measurement direction at a predetermined angle according to a first rotation direction in the horizontal direction at an arbitrary point and a second gas concentration measurement result through laser irradiation in each measurement direction at a predetermined angle according to a second rotation direction in the vertical direction at the arbitrary point; and calculates the intersection point of each measurement direction where gas is detected based on the first gas concentration measurement result and the second gas concentration measurement result at a plurality of points different from the arbitrary point, thereby obtaining a three-dimensional gas detection result at the location of the detection target. 3D gas detection device. Claim 2 A TDLAS-based 3D gas detection device according to claim 1, wherein the mobile robot platform includes a position recognition unit for recognizing the movement position of the mobile robot platform at a location to be detected and the direction of the mobile robot platform, and the gas detection sensor confirms the measurement position of the detection sensor based on the position of the mobile robot platform transmitted from the position recognition unit. Claim 3 A TDLAS-based 3D gas detection device according to claim 2, wherein the position recognition unit recognizes the movement position and direction based on the relative position with respect to a plurality of position recognition indicators installed at a location to be detected. Claim 4 A TDLAS-based 3D gas detection device according to claim 3, characterized in that the mobile robot platform determines the movement direction and movement position of the mobile robot platform based on a pre-stored detection map corresponding to the location to be detected and relative position information with the position recognition indicator. Claim 5 A TDLAS-based 3D gas detection device according to claim 3, wherein the mobile robot platform determines an arbitrary direction of movement and a position of movement, creates and updates a detection map of a location to be detected at the corresponding point, and determines the direction of movement and the position of movement of the mobile robot platform based on the created detection map and relative position information with the position recognition indicator. Claim 6 delete Claim 7 A TDLAS-based 3D gas detection device according to claim 1, wherein the gas detection sensor obtains gas concentration measurement results by laser irradiation in each measurement direction at a predetermined angle according to a rotational direction in the horizontal direction at any one point, and calculates the intersection points of each measurement direction where gas is detected based on gas concentration measurement results according to each measurement direction at a predetermined angle at a plurality of points different from the arbitrary one point, thereby obtaining gas detection results at a location to be detected. Claim 8 A TDLAS-based 3D gas detection device according to claim 1, characterized in that the gas detection sensor stores the location where gas is detected at the location to be detected, creates a gas distribution map of the location to be detected based on this, and selects the previously stored gas detection location as a priority monitoring target. Claim 9 A TDLAS-based three-dimensional gas detection device according to claim 1, characterized in that the gas detection sensor performs angle adjustment for laser irradiation at any point randomly or sequentially in a predetermined direction.

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