JP2017110984A - Gas detection system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable good and accurate gas detection.SOLUTION: The above problem is cleared by providing a gas detection system 100 comprising a plurality of mobile bodies 10A, 10B, and a detection controller 60 configured to detect a target gas present between the plurality of mobile bodies by projecting and receiving measurement light that travels between the plurality of mobile bodies, the measurement light having a wavelength in an absorption wavelength band of the target gas. The system may be configured to have one mobile body with a light projector 21 for projecting the measurement light and the other mobile body with a light receiver 22 for receiving the measurement light, or to have one mobile body with both the light projector for projecting the measurement light and the light receiver for receiving the measurement light and the other mobile body with a reflector 20B for reflecting the measurement light.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a gas detection system using a moving body.

  As a method of detecting gas leakage due to deterioration of piping in city gas or chemical plants, etc., a traveling vehicle equipped with a gas sensor is autonomously driven in the gas detection area, and when the gas is detected, the traveling vehicle is further rotated 360 °. Thus, a method has been proposed in which the direction of the gas generation source is specified and the position of the gas generation source is detected more accurately (see, for example, Patent Document 1).

  As another method of gas detection, a light projecting means and a light receiving means for projecting measurement light in the gas absorption wavelength band are mounted on a traveling vehicle or airplane, and reflected light of measurement light irradiated on a background object or the ground is used. There has been proposed a method of detecting light from a decrease in the amount of light received due to gas absorption (see, for example, Patent Document 2).

  As another method of gas detection, a light source unit that is installed at a high position in the gas detection area and projects measurement light in the gas absorption wavelength band, and a swivel tilt that makes the projection direction and elevation angle of the measurement light variable. A mechanism that includes a mechanism and a mobile station that moves in the gas detection area and receives measurement light, and receives the measurement light at various locations in the gas detection area, and performs gas detection from a decrease in the amount of light received due to gas absorption. Has been proposed (see, for example, Patent Document 3).

Japanese Patent No. 3620886 Japanese Patent No. 4695827 Japanese Patent No. 4823020

However, since the prior art of Patent Document 1 performs gas detection using a metal oxide semiconductor gas sensor, it is easily affected by wind and the like, and measurement at a single point of the gas present at the measurement position is possible. There was a problem that the range was narrow and it was difficult to identify the leak location.
In the prior art of Patent Document 2, gas detection is performed by receiving measurement light in a gas absorption wavelength band by laser light. However, since reflected light of measurement light irradiated on a background object or the ground is used, irradiation is performed. It is easily affected by the state, structure, material, etc. of the surface of the object, and in this case as well, it is difficult to accurately detect the gas.
Furthermore, the prior art of Patent Document 3 has a problem in that gas detection cannot be performed for an area shielded by undulations or buildings on the ground because the light source unit is installed at a fixed position.

  The present invention has been made in view of the above problems in the prior art, and an object of the present invention is to perform gas detection well and accurately.

The invention according to claim 1 for solving the above-described problems is provided in a gas detection system.
Multiple mobiles,
A detection control unit that performs gas detection between the plurality of moving bodies by projecting and receiving measurement light in an absorption wavelength band of the gas to be detected across the plurality of moving bodies. .

The invention according to claim 2 is the gas detection system according to claim 1,
One of the moving bodies includes a light projecting unit that projects the measurement light,
Another one of the moving bodies includes a light receiving unit that receives the measurement light.

The invention described in claim 3 is the gas detection system according to claim 1,
One of the moving bodies includes a light projecting unit that projects the measurement light and a light receiving unit that receives the measurement light,
Another one of the moving bodies includes a reflection part that reflects the measurement light.

The invention according to claim 4 is the gas detection system according to any one of claims 1 to 3,
The detection control unit performs gas detection by wavelength modulation spectroscopy.

Invention of Claim 5 is a gas detection system as described in any one of Claim 1 to 4,
One of the mobile bodies includes a route storage unit that stores a travel route,
Gas detection is performed on the travel route.

The invention according to claim 6 is the gas detection system according to any one of claims 1 to 4,
One of the moving bodies is
An area storage unit for storing detection area information;
A movement control unit for autonomously moving in the detection area,
Gas detection is performed in the detection area.

The invention according to claim 7 is the gas detection system according to any one of claims 1 to 6,
When the gas is detected between the two moving bodies, the detection control unit performs gas detection by reducing a distance between the two moving bodies.

The invention according to claim 8 is the gas detection system according to any one of claims 1 to 7,
All of the moving bodies are flying bodies.

The invention according to claim 9 is the gas detection system according to claim 8,
When the gas is detected between the two flying bodies, the detection control unit performs gas detection by changing the height of the two flying bodies.

The invention according to claim 10 is the gas detection system according to any one of claims 1 to 7,
One of the moving bodies is a flying body,
Another one of the moving bodies is a traveling vehicle.

The invention according to claim 11 is the gas detection system according to any one of claims 1 to 10,
A projection direction adjusting mechanism for adjusting the projection direction of the measurement light is provided.

According to the present invention, gas detection is performed between a plurality of moving bodies by projecting and receiving the measurement light in the absorption wavelength band of the gas to be detected across the plurality of moving bodies. The leakage position can be accurately estimated. In addition, since the measurement light passes between the moving body and the moving body, unlike the case of irradiating the background object or the ground with the measurement light, the influence of the surface condition of the projection destination is sufficiently reduced and highly accurate gas detection is possible. Can be performed.
Furthermore, since gas detection is performed among a plurality of moving bodies, gas detection can be performed by moving to a place that is susceptible to the influence of undulations on the ground and shielding by buildings, and gas detection can be performed. The range can be expanded dramatically.

It is a top view of a schematic structure of a gas detection system of a first embodiment. It is a block diagram of the gas detection system of a first embodiment. It is explanatory drawing which shows the detection area and movement route of a gas detection system. It is operation | movement explanatory drawing of 1st detail detection control. It is operation | movement explanatory drawing of 2nd detailed detection control. It is a flowchart of the gas detection operation | movement of a gas detection system. It is a block diagram of the gas detection system of a second embodiment. It is a side view of schematic structure of the gas detection system of 3rd embodiment. It is explanatory drawing which shows the example which provided the light projection direction adjustment mechanism side by side with the light projection part.

[First embodiment]
A gas detection system according to a first embodiment of the present invention will be described with reference to the drawings. The following is one embodiment of the present invention and does not limit the present invention.
FIG. 1 is a plan view of a schematic configuration of a gas detection system 100 according to the present embodiment as viewed from above, and an X-axis direction and a Y-axis direction in the drawing indicate horizontal directions orthogonal to each other. Further, the Z-axis direction shown in other figures described later indicates a vertical vertical direction orthogonal to both the X-axis direction and the Y-axis direction.

The gas detection system 100 is for detecting a location where a gas such as methane or carbon dioxide is generated.
As shown in FIGS. 1 to 3, the gas detection system 100 is composed of flying bodies 10 </ b> A and 10 </ b> B as two moving bodies. Measurement of the absorption wavelength band of the gas G to be detected across the two aircrafts 10A and 10B while these two aircrafts 10A and 10B move throughout the predetermined detection area A. Gas detection is performed by projecting and receiving light. That is, the measuring light projecting / receiving direction (horizontal direction) between the flying object 10A and the flying object 10B is the main scanning direction, and the moving direction of each flying object 10A, 10B (in principle, the horizontal direction perpendicular to the projecting direction) is the sub-scanning direction. As the scanning direction, the gas detection of the entire detection area A is performed in a band shape along the movement route R in FIG.

Each of the flying bodies 10A and 10B has four rotors, and can freely move up and down, move back and forth, and move forward and backward by controlling the output of a motor that is a driving source of each rotor. This is a so-called drone.
The flying object 10A moves in the detection area A according to a predetermined moving route R, and the flying object 10B moves side by side at a certain distance next to the flying object 10A by the function of following the flying object 10A. That is, the flying object 10A and the flying object 10B are in a so-called master-slave relationship.

[Aircraft (Master)]
FIG. 2 is a block diagram showing a control system of the flying bodies 10A and 10B. As illustrated, the flying object 10A includes a light projecting unit 21 for projecting measurement light toward the flying object 10B, a light receiving unit 22 for receiving the measurement light reflected on the flying object 10B, and a front side. A pair of front-view camera L31 and front-view camera R32 as an obstacle detection unit for detecting the obstacle, a positioning unit 41 for detecting the position of the flying object 10A, and an orientation for detecting the direction in which the flying object 10A is facing A sensor 42, a height sensor 43 for detecting the height of the flying object 10A, a driving unit 50 including four motors as driving sources for the moving operation of the flying object 10A, and a control unit 60 for controlling each of the above components. A data storage unit 61 that mainly stores various information and control programs related to the control of the flying object 10A.

The light projecting unit 21 is mainly composed of a light emitting element such as a laser diode and a light projecting optical system that collects measurement light from the light emitting element.
The light emitting element projects the measurement light in the absorption wavelength band absorbed by the gas G to be detected to the side. When the measurement light in the absorption wavelength band passes through the atmosphere of the gas G, it is absorbed and the amount of light decreases. The wavelength band varies depending on the type of gas G to be detected.
For example, when the detection target is methane gas, measurement light having a wavelength of 1.65372 [μm] is a desirable absorption wavelength band.

  The light projecting unit 21 is provided with a modulation unit 23, whereby the measurement light modulated at a predetermined frequency (for example, a range up to about 10 MHz) is projected from the light emitting element. The modulation of the measurement light is a process for performing gas detection by wavelength modulation spectroscopy described later.

The light receiving unit 22 mainly includes a light receiving element such as a photodiode and a light receiving optical system that collects the measurement light from the light projecting unit 21 reflected by the flying object 10B.
The light receiving element is disposed such that the light receiving surface is oriented in the same direction as the light emitting element at the focal length of the condensing lens constituting the light receiving optical system, and receives the reflected measurement light from the side.

The light receiving unit 22 is provided with a demodulation unit 24. The demodulation unit 24 generates a signal obtained by demodulating the received measurement light detection signal at the same frequency as the modulation unit 23 and a signal obtained by demodulating the received measurement light detection signal at a frequency twice that of the modulation unit 23. Further, the demodulator 24 divides the signal demodulated at the same cycle as the modulator 23 by the signal demodulated at a cycle twice that of the modulator 23, thereby generating a detection signal of the gas to be detected, and the control unit Enter 60.
In the control unit 60, the presence or absence of a decrease in received light intensity due to gas absorption is determined from the gas detection signal input from the demodulator 24. If a decrease in received light intensity has occurred, the degree of decrease is determined. Calculate the concentration.
That is, the control unit 60 cooperates with the light projecting unit 21, the modulation unit 23, the light receiving unit 22, and the demodulation unit 24 to perform gas detection between the aircrafts 10A and 10B by wavelength modulation spectroscopy. ”.

The front-view camera L31 and the front-view camera R32 are arranged at a predetermined distance toward the front, and are used for recognizing an obstacle by imaging the front when the flying object 10A is flying.
The captured image data of the front view camera L31 and the front view camera R32 is input to the image processing unit 33. The image processing unit 33 extracts obstacles from the captured images of the front-view camera L31 and the front-view camera R32, and the position of the obstacle in the imaging range of the front-view camera L31 and the imaging of the front-view camera R32. The position of the obstacle within the range is specified and input to the control unit 60.

The controller 60 determines the obstacle based on the position of the obstacle in the imaging range of the front-view camera L31, the position of the obstacle in the imaging range of the front-view camera R32, and the positional relationship between the front-view camera L31 and the front-view camera R32. Calculate the position and distance of the object.
Further, the control unit 60 controls the driving unit 50 based on the calculated position and distance of the obstacle, and controls the flight direction so that the flying object 10A bypasses the obstacle.

The positioning unit 41 is a GPS (Global Positioning System) receiver and measures the current position of the flying object 10A.
The azimuth sensor 42 is a triaxial gyro azimuth sensor, and detects the traveling direction of the flying object 10A and the inclination angle of the aircraft.
The flying object 10A flies along the prescribed movement route R with the front of the aircraft facing the downstream side of the movement route R by the position detection by the positioning unit 41 and the traveling direction detection by the direction sensor 42.
The height sensor 43 is, for example, an optical type, and a known sensor that projects light vertically downward and obtains the height from the phase difference generated in the reflected light is used.
When flying along the moving route R, the flying object 10A detects the height by the height sensor 43 and performs the flight so as to maintain the specified height.

  The control unit 60 is a computer for performing a plurality of processes or control required for gas detection of the flying object 10A, and includes a processor, a communication device, an interface, and the like (not shown).

[Aircraft (slave)]
Regarding the aircraft 10B on the slave side, the same components as those on the aircraft 10A on the master side are denoted by the same reference numerals and redundant description is omitted.
As shown in FIG. 2, the flying object 10 </ b> B includes a reflecting plate 20 </ b> B as a reflecting part that reflects measurement light projected from the flying object 10 </ b> A and a pair of fronts as an obstacle detecting part that detects an obstacle in front. A pair of tracking camera L34B and tracking camera R35B as capturing means for capturing the flying object 10A in the field of view in order to fly following the flying object 10A on the side, and the flying object 10B. Positioning unit 41 for detecting the position of the aircraft, an orientation sensor 42 for detecting the orientation of the flying object 10B, a height sensor 43 for detecting the height of the flying object 10A, and a driving source for the moving operation of the flying object 10B A drive unit 50 including four motors, a control unit 60B for controlling each of the above components, and a data storage unit 61 for storing various information and control programs related to the control of the flying object 10B. Mainly equipped with a door.

The reflecting plate 20B is fixedly supported by the flying object 10B with its reflecting surface facing side (for example, the left side), and the light projecting unit 21 of the flying object 10A emits measurement light from the direction facing the reflecting plate 20B. By performing the light projection, the light receiving unit 22 can receive the reflected measurement light.
The reflection plate 20B is a so-called reflector, and scatters and reflects the measurement light on the reflection surface thereof, so that the light receiving unit 22 of the flying object 10A reflects even if the measurement light does not enter the reflection surface exactly perpendicularly. The measured light can be received.
With these configurations, when a gas is present between the flying object 10A and the flying object 10B, the measurement light projected from the flying object 10A or the reflected measurement light passes through the gas atmosphere and is absorbed, Gas detection can be performed from a decrease in received light intensity.

The follow-up camera L34B and the follow-up camera R35B are arranged apart from each other by a predetermined distance, and are used for recognizing the flying object 10A by imaging the side when the flying object 10B is flying.
The captured image data of the tracking camera L34B and the tracking camera R35B is input to the image processing unit 33B. In this image processing unit 33B, the flying object 10A is extracted from the captured images of the tracking camera L34B and the tracking camera R35B, and the position of the flying object 10A within the imaging range of the tracking camera L34B and the imaging range of the tracking camera R35B. The position of the flying object 10A is identified and input to the control unit 60.

  In principle, the flying object 10B maintains a fixed position with respect to the flying object 10A and performs a follow-up movement so as to maintain a fixed direction with respect to the flying object 10A. Although the sensor 42 is unnecessary, when the obstacle is detected by the foresight camera L31 and the foresight camera R32 and the detour flight is performed, when the flying object 10B is returned to the prescribed moving route R, the positioning unit 41 and An orientation sensor 42 is used.

  The control unit 60B is a computer for performing a plurality of processes or controls required for gas detection of the flying object 10A, and includes a processor, a communication device, an interface, and the like (not shown).

[Control in the control unit of each aircraft]
The control unit 60 of the flying object 10A mainly performs cruise control for performing gas detection while flying in the set detection area A according to a predetermined movement route R, and a position where gas is detected on the movement route R. The first detailed detection control for detecting the gas while approaching the side of the slave aircraft 10B, and narrowing down the gas detection position, and at the position where the gas is detected on the moving route R, the slave aircraft 10B. At the same time, gas detection is performed while moving up or down, and second detailed detection control is performed to narrow down the gas detection position.
Thereby, the control unit 60 functions as a “movement control unit”.

  In addition, the control unit 60B of the flying object 10B performs follow-up control for flying so as to maintain a predetermined position and a predetermined distance on the side (for example, the right side) of the flying object 10A. In this follow-up control, the height is followed and the ascending / descending operation follows the flying object 10A so that the flying object 10B maintains the same height.

[Cruise control]
FIG. 3 shows a detection area A and a travel route R in cruise control. Data regarding the detection area A and the travel route R is input from the outside through a communication device included in the control unit 60, and the received data on the detection area A and the travel route R is stored in the data storage unit 61. That is, the data storage unit 61 functions as a “route storage unit” and an “area storage unit”.
Note that the flying object 10B also receives data related to the detection area A and the moving route R from the outside through the communication device of the control unit 60B and stores the data in the data storage unit 61. Therefore, the data storage unit 61B is also a “route storage unit”. And it functions as an “area storage unit”.

For the detection area A, position data composed of the latitude and longitude indicating the position of the position serving as the reference point of the area shape (for example, each vertex in the case of a polygonal area shape) is input.
For the movement route R, position coordinate data of a plurality of passing points on the movement route R is input. The position coordinate data is data indicating the position of each passing point in the position coordinates based on the coordinate system set in the detection area A. For example, the position coordinates of the passing point of the moving route R are composed of latitude and longitude. When setting by position coordinates, the detection area A may not be determined.
The control unit 60 recognizes the current position of the aircraft and the orientation of the aircraft from the positioning unit 41 and the direction sensor 42 when the flying vehicle 10A moves in cruise control, and flies toward each passing point in a predetermined order. The drive unit 50 is controlled.
In addition, during movement, the measurement light is projected by the light projecting unit 21 and the measurement light is received by the light receiving unit 22 continuously, and the current position and the detected gas concentration are determined at a predetermined sampling period. Record. Further, the control unit 60 determines the presence or absence of gas from the detected gas concentration, and if it is determined that there is gas, the position coordinates (or latitude and longitude) when determining that there is gas are used as the gas detection position. Store in the data storage unit 61.

  Further, during the movement of the movement route R in the cruise control, the control unit 60 of the flying object 10A stops the movement along the movement route R and determines the first detailed detection control and the The second detailed detection control is executed.

[First detailed detection control]
FIG. 4 shows operations of the flying object 10A and the flying object 10B in the first detailed detection control.
In the first detailed detection control, the control unit 60 controls the drive unit 50 to move the flying object 10A closer to the flying object 10B at the position determined to have gas on the moving route R.
As described above, the flying object 10B performs follow-up control so as to maintain a predetermined distance at a predetermined position with respect to the flying object 10A.
In contrast, the data storage unit 61 of the flying object 10A stores location data indicating at which position the flying object 10B is following the flying object 10A by the follow-up control. Therefore, when the first detailed detection control is executed, the position of the flying object 10B is specified from the location data, and the flying object 10A is moved toward the specified position of the flying object 10B. It should be noted that the moving amount of the flying object 10A is within a range that does not cause interference with the flying object 10B. During this movement, gas detection is performed and the change in concentration is recorded.
Then, the control unit 60 records an intermediate point between the position of the flying object 10A and the position of the flying object 10B when the gas concentration becomes the highest as the newly detected gas detection position.

  In the first detailed detection control, when the flying object 10A moves to the flying object 10B side, the flying object 10B is moved in the direction away from the flying object 10A by the follow-up control, and control for maintaining a certain distance is performed. Therefore, the control unit 60 of the flying object 10A communicates with the control unit 60B of the flying object 10B so as to maintain the current position without performing tracking control during execution of the first detailed detection control. Send a command.

[Second detailed detection control]
FIG. 5 shows the operations of the flying object 10A and the flying object 10B in the second detailed detection control.
In the second detailed detection control, the control unit 60 controls the drive unit 50 to raise or lower the flying object 10A within a predetermined height range at a position determined to have gas on the movement route R. .
When the flying object 10A moves up or down, the flying object 10B moves up or down so as to maintain the same height as the flying object 10A by the follow-up control.
And at the time of execution of 2nd detailed detection control, the control part 60 performs gas detection in the ascending, descending or both of the flying body 10A, and records the change in concentration.
Then, the control unit 60 records the height of the flying object 10A when the gas concentration becomes the highest together with the gas detection position.

[Follow-up control]
The control unit 60B of the flying object 10B performs imaging by the tracking camera L34B and the tracking camera R35B during flight. The image processing unit 33B obtains the position of the flying object 10A within the imaging range of the tracking camera L34B and the position of the flying object 10A within the imaging range of the tracking camera R35B, and inputs them to the control unit 60B.
The control unit 60B determines the flying object 10A from the position of the flying object 10A within the imaging range of the tracking camera L34B, the position of the flying object 10A within the imaging range of the tracking camera R35B, and the positional relationship between the tracking camera L34B and the tracking camera R35B. The distance at which the flying object 10B is located is calculated.
Further, the control unit 60B performs follow-up movement control based on the calculated position and distance of the flying object 10B with respect to the calculated flying object 10A. That is, the control unit 60B controls the drive unit 50 based on the calculated position and distance of the flying object 10B with respect to the calculated flying object 10A so that the flying object 10B has a predetermined position and distance with respect to the flying object 10A.

  In addition, the image processing unit 33B and the control unit 60B of the flying object 10B described above are similar to the image processing unit 33 and the control unit 60 of the flying object 10A, from the captured images of the front-view camera L31 and the front-view camera R32. The position and distance are calculated, and detour control for controlling the drive unit 50 so that the flying object 10A detours the obstacle is also executed.

[Gas detection operation by gas detection system]
The gas detection operation by the gas detection system 100 will be described based on the flowcharts of FIGS. 1 to 5 and 6.
When the settings relating to the detection area A and the moving route R are made to the control units 60 and 60B of the flying objects 10A and 10B (step S1), the flying object 10A starts flying along the moving route R based on cruise control. To do. The flying object 10B flies to the side of the flying object 10A by the follow-up control, and the two flying objects 10A and 10B translate along the movement route R (step S3).
While translating along the movement route R, the flying object 10A projects measurement light from the light projecting unit 21 toward the reflector 20B of the flying object 10B, and the reflected light is received by the light receiving unit 22. The gas detection is executed periodically. Then, the control unit 60 of the flying object 10A records the position coordinates and the detected gas concentration when the periodic gas detection is executed.

Further, the control unit 60 of the flying object 10A determines the presence or absence of gas from the gas concentration detected during the flight of the moving route R (step S5).
When it is determined that there is no gas, the process proceeds to the determination of reaching the end point of the moving route R (step S11). When it is determined that there is gas, the translation by the flying bodies 10A and 10B is stopped, and the first detailed detection control is performed. Execute (Step S7). That is, gas detection is performed while the flying object 10A is moved closer to the flying object 10B, and a change in gas concentration is monitored.
Then, the position coordinates of the intermediate point between the flying object 10A and the flying object 10B when the gas concentration reaches the maximum value within the moving range of the approaching movement of the flying object 10A and the detected gas concentration are recorded.

Further, second detailed detection control is executed at a position where it is determined that there is gas and the translation by the flying bodies 10A, 10B is stopped (step S9). That is, gas detection is performed while the flying object 10A and the flying object 10B are moved up or down, and changes in gas concentration are monitored.
Then, the height at which the gas concentration reaches the maximum value within the movement range along the Z-axis direction of the flying object 10A and the detected gas concentration are recorded.

  Next, the control unit 60 of the flying object 10A determines whether or not the end point of the travel route R has been reached (step S11). If the end point has not been reached, the control unit 60 returns to step S3 and uses the flying objects 10A and 10B. If the translation of the movement route R is continued and it is determined that the end point has been reached, the operation is terminated assuming that the gas detection has been completed for the entire detection area A.

[Technical effects of gas detection system]
As described above, in the gas detection system 100, the two aircraft 10A and 10B are projected and received by measuring light in the absorption wavelength band of the gas to be detected across the two aircraft 10A and 10B. Because it detects gas between them, it is difficult to be affected by wind etc., and the leak position can be estimated accurately, and unlike the case of irradiating measurement light to a background object or the ground, the influence of the surface condition of the projection destination It is possible to sufficiently detect gas with high accuracy.
Furthermore, since gas detection is performed between the two aircrafts 10A and 10B, the gas detection can be performed by moving to a position that is easily affected by undulations on the ground or shielding by buildings. It is possible to dramatically expand the possible range.
Further, since the flying bodies 10A and 10B are used as the moving bodies, it is difficult to be influenced by the ground surface and topography like a traveling vehicle, and it is possible to perform gas detection in a wider range and without any difficulty.

  In addition, the flying object 10A includes a light projecting unit 21 that projects measurement light and a light receiving unit 22 that receives the measurement light, and the flying object 10B includes a reflector 20B that reflects the measurement light. Measurement light reflected in a constant reflection state can be used for gas detection, and gas detection can be performed stably and accurately.

Further, the control unit 60 of the flying object 10A performs gas detection between the flying objects 10A and 10B by wavelength modulation spectroscopy in cooperation with the light projecting unit 21, the modulation unit 23, the light receiving unit 22, and the demodulation unit 24. Therefore, even when the received light intensity of the reflected measurement light is low, a weak intensity change due to gas detection can be detected, and gas detection with higher accuracy can be performed.
In addition, since a slight change in the light receiving intensity of the measurement light can be detected, the distance between the aircrafts 10A and 10B can be increased, and gas detection can be performed efficiently even in a wide detection area.

In addition, since the flying object 10A includes the data storage unit 61 that stores the movement route R and performs gas detection on the movement route R, it is possible to perform gas detection as planned within the assumed detection range. Become.
In addition, since the flying object 10A also stores the detection area A in the data storage unit 61, it is possible to perform gas detection without departing from the assumed detection range.

  Furthermore, when gas is detected between the flying object 10A and the control unit 60 of the flying object 10A, the first detailed detection control that performs gas detection by reducing the distance between the two flying objects 10A and 10B. Therefore, it is possible to narrow down the detection position where there is gas more accurately.

  Furthermore, when gas is detected between the flying object 10B and the control unit 60 of the flying object 10A, the second detailed detection control for performing gas detection by changing the height of the two flying objects 10A and 10B is performed. Therefore, it is possible to detect at which height the gas is present at the detection position where the gas is present.

[Second Embodiment]
A gas detection system 100C according to the second embodiment of the present invention is shown in a block diagram of FIG.
This gas detection system 100C is composed of aircrafts 10C and 10D obtained by changing a part of the configuration of the aircrafts 10A and 10B of the gas detection system 100 described above. In the following description, the aircraft 10C and 10D will be described mainly with respect to differences from the aircraft 10A and 10B, and the same components as those of the gas detection system 100 will be denoted by the same reference numerals and redundant description will be omitted.

The flying object 10C on the master side has a configuration in which the light projecting unit 21 and the modulation unit 23 of the flying object 10A are removed. That is, the flying object 10C does not project the measurement light, but only receives the measurement light.
The slave-side flying object 10D has a configuration in which the reflector 20B is removed from the flying object 10B and a light projecting unit 21 and a modulating unit 23 are added. The light projecting unit 21 of the flying object 10D is directed in the same direction as the direction in which the reflecting surface of the reflecting plate 20B is directed. That is, the light projecting unit 21 of the flying object 10D projects the measurement light toward the flying object 10C when the tracking movement of the flying object 10C is performed by the tracking control.

The flying object 10D always projects measurement light from the light projecting unit 21 during flight.
In other cases, the flying bodies 10C and 10D perform gas detection by performing the same control as the flying bodies 10A and 10B.

  With the above configuration, the gas detection system 100C can obtain the same technical effect as the gas detection system 100. Furthermore, since the gas detection system 100C does not use the reflection plate 20B, the measurement light can be directly received without passing through the reflection plate 20B, and the gas detection can be detected with better and high accuracy by suppressing the decrease in the received light intensity. Can be performed. Further, since there is no reflection, it is possible to widen the space between the flying object 10C and the flying object 10D at the time of gas detection.

[Third embodiment]
A gas detection system 100E according to the third embodiment of the present invention is shown in a side view of FIG.
The gas detection system 100E has a configuration in which the moving body on the master side of the gas detection system 100 described above is changed from the flying body 10A to the traveling vehicle 10E, and gas detection is performed by the traveling vehicle 10E and the flying body 10B.
In the following description, the traveling vehicle 10E will be described mainly with respect to differences from the flying object 10A, and the same components as those in the gas detection system 100 will be denoted by the same reference numerals and redundant description will be omitted.

The traveling vehicle 10E on the master side includes the light projecting unit 21 and the light receiving unit 22 (see FIG. 2) facing upward, and does not include the height sensor 43.
The slave aircraft 10B includes a reflector 20B, a follower camera L34B, and a follower camera R35B (see FIG. 2) facing vertically downward.
In this gas detection system 100E, gas detection is performed in a state where the traveling vehicle 10E and the flying object 10B are aligned vertically.
Therefore, the first detailed detection control of the gas detection system 100 is not executed.
In the second detailed detection control, the slave-side flying object 10B performs gas detection while performing ascending or descending operation.

  The gas detection system 100E obtains the same technical effect as the gas detection system 100 except that gas detection cannot be performed in a place where the vehicle cannot travel and the first detailed detection control cannot be performed. be able to. Furthermore, since one moving body is a traveling vehicle, the gas detection system 100E can easily realize operation control for performing gas detection in conjunction with the two moving bodies, compared to the case where both are flying bodies. Is possible.

[Others]
In each said embodiment, although the multicopter which has four rotors as a flying body was illustrated, the number of rotors may differ. A single rotor type or twin rotor type helicopter may also be used.

  In each of the above embodiments, the signal component obtained by modulating the measurement light projected from the light projecting unit 21 at a predetermined frequency and detecting the received light signal of the light receiving unit 22 at twice the modulation frequency (2f detection) is used. Gas detection is performed by the so-called 2f detection method (wavelength modulation spectroscopy) to obtain a gas detection signal divided by the signal component detected at the modulation frequency. You may detect with. In addition to the wavelength modulation spectroscopy, the light projecting unit 21 projects the measurement light in the absorption wavelength band and the measurement light in the non-absorption wavelength band, and the light receiving unit 22 measures the measurement light in the absorption wavelength band and the non-absorption wavelength. A method (differential absorption method) in which the measurement light in the band is received and the control unit 60 detects the gas from the ratio of the amount of the measurement light in the absorption wavelength band and the measurement light in the non-absorption wavelength band may be employed.

Further, in each of the above embodiments, the case where the master-side moving body moves according to the prescribed moving route R has been exemplified. However, the present invention is not limited to such autonomous movement, and the operator moves in the detection area A by remote control. It is good also as a structure made to do.
In addition, even when autonomous movement is performed, the present invention is not limited to movement according to the prescribed movement route R, and the current position is detected and controlled so as not to deviate from the detection area A. Gas detection may be performed while moving so as to fill the entire region in order from the end. Alternatively, the gas detection may be performed while moving so as to fill the entire region while randomly changing the direction while performing control so as not to depart from the detection area A.

Further, in the gas detection system 100, when the gas is detected, the control unit 60 of the flying object 10A executes the first detailed detection control and the second detailed detection control even during the movement route R. Although the case is illustrated, the present invention is not limited to this, and after the gas detection of the entire travel route R by the cruise control is completed, the first detailed detection control and the second detailed detection control are executed for each position where the gas is detected. Also good.
Further, either the first detail detection control or the second detail detection control may be performed first.

  Moreover, in each embodiment, although the case where there were two mobile bodies was illustrated, more mobile bodies may be used. In that case, it is desirable to prepare a plurality of sets of two moving bodies, divide the detection area A into a plurality of sections, and perform gas detection in each section for each set.

Further, when the moving body is a flying body such as a multicopter, an inclination is inevitably generated when the flying body moves.
Therefore, in each of the flying bodies 10A, 10B, 10C, and 10D, a configuration that needs to maintain a constant direction, for example, a light projecting unit 21, a light receiving unit 22, a reflecting plate 20B, a front camera L31, a front camera R32, The follower camera L34B, the follower camera R35B, the height sensor 43, and the like may be provided in the aircraft via a tilt mechanism that can be arbitrarily tilted with respect to the aircraft. In that case, the control unit 60 detects the tilt angle of the airframe by the azimuth sensor 42 during the flight of the flying object, and the light projecting unit 21, the light receiving unit 22, the reflector 20B, the front camera L31, the front camera R32, and the following camera. L34B, follow-up camera R35B, height sensor 43, etc. may control the tilt mechanism so as to maintain the orientation when the aircraft is in a horizontal state.
Further, for the reflector 20B, a reflector having an optical structure that emits the reflected light in parallel with the direction in which the incident light is incident may be used.

  The data storage unit 61 may be composed of a removable recording medium such as a memory card and its reading / writing device.

Moreover, in each said embodiment, although light projection is performed with respect to the reflecting plate 20B or the light-receiving part 22 of the other moving body from the light projection part 21 of one moving body, about this light projection, it is in FIG. As shown, it is good also as a structure which projects light via the light projection direction adjustment mechanism 211 which adjusts the light projection direction of the measurement light from the light projection part 21. FIG. As the light projecting direction adjusting mechanism 211, a mechanism that arbitrarily changes and adjusts the direction of the optical element that performs reflection or refraction can be used. Specifically, a MEMS (Micro Electro Mechanical Systems) mirror or the like is preferable. The MEMS mirror can tilt the mirror uniaxially or biaxially, and the control unit 60 (or 60B) that has acquired the position information of the moving body on the other side determines the mirror angle of the MEMS mirror based on the position information. Control is performed so that light is projected onto the reflecting plate 20B or the light receiving unit 22 of the moving body on the other side. In addition, when the control unit 60 (or 60B) does not acquire the position information of the moving body on the other side, the projection angle is expanded by periodically tilting the mirror angle so that projection is performed with a constant swing width. Control may be performed.
By providing the light projection direction adjusting mechanism 211, the measurement light can be received more favorably, and gas detection can be performed more stably and accurately.

10A, 10B, 10C, 10D Aircraft (moving object)
10E Traveling vehicle (moving body)
20B Reflector (reflector)
DESCRIPTION OF SYMBOLS 21 Light projection part 211 Light projection direction adjustment mechanism 22 Light receiving part 23 Modulation part 24 Demodulation part 33 Image processing part 33B Image processing part 41 Positioning part 42 Direction sensor 43 Height sensor 50 Drive part 60 Control part (detection control part, movement control) Part)
60B control unit 61, 61B data storage unit (route storage unit, area storage unit)
100, 100C, 100E Gas detection system A Detection area G Gas 31 Front-view camera L
32 Front-view camera R
34B Tracking camera L
35B tracking camera R
R Travel route

Claims (11)

Multiple mobiles,
A detection control unit that performs gas detection between the plurality of moving bodies by projecting and receiving measurement light in an absorption wavelength band of the gas to be detected across the plurality of moving bodies. Gas detection system. One of the moving bodies includes a light projecting unit that projects the measurement light,
The gas detection system according to claim 1, wherein another one of the moving bodies includes a light receiving unit that receives the measurement light. One of the moving bodies includes a light projecting unit that projects the measurement light and a light receiving unit that receives the measurement light,
The gas detection system according to claim 1, wherein the other one of the movable bodies includes a reflection unit that reflects the measurement light.   The gas detection system according to any one of claims 1 to 3, wherein the detection control unit performs gas detection by wavelength modulation spectroscopy. One of the mobile bodies includes a route storage unit that stores a travel route,
The gas detection system according to any one of claims 1 to 4, wherein gas detection is performed on the travel route. One of the moving bodies is
An area storage unit for storing detection area information;
A movement control unit for autonomously moving in the detection area,
The gas detection system according to any one of claims 1 to 4, wherein gas detection is performed in the detection area.   The said detection control part performs gas detection by shortening the distance between the said two mobile bodies, when gas is detected between the two said mobile bodies. The gas detection system according to one item.   The gas detection system according to any one of claims 1 to 7, wherein each of the moving bodies is a flying body.   The gas detection system according to claim 8, wherein when the gas is detected between the two flying objects, the detection control unit performs gas detection by changing the height of the two flying objects. One of the moving bodies is a flying body,
The gas detection system according to claim 1, wherein the other one of the moving bodies is a traveling vehicle.   The gas detection system according to any one of claims 1 to 10, further comprising a light projection direction adjustment mechanism that adjusts a light projection direction of the measurement light.

Images