Method for measuring data representative of the contents of at least one gas present on the ground, drone and associated measurement kit

Abstract

Method for measuring data representative of contents of at least one gas present on the ground, associated drone and measurement kit This method comprises: - movement on a measurement path on the ground, of an operator and / or a robot carrying a measurement assembly (16) comprising a support, and, carried by the support, a sensor for measuring data representative of contents of the at least one gas and a sensor for positioning the measurement assembly (16), and - successive measurements of data representative of contents of the at least one gas along the measurement path, The method comprises, before movement on the ground, reversible disassembly of the measurement assembly (16) from a drone for measuring data representative of contents of at least one gas, and / or after movement on the ground, reversible reassembly of the measurement assembly (16) on a drone for measuring data representative of contents of at least one gas. Figure for abstract: figure 4

Description

Title of the invention: Method for measuring data representative of the contents of at least one gas present on the ground, drone and associated measurement kit

[0001] The present invention relates to a method for measuring data representative of contents of at least one gas present in the ground, comprising the following step:

[0002] - movement on a ground measurement path, of an operator and / or a robot carrying a measuring assembly comprising a support, and, carried by the support, a sensor for measuring data representative of contents of at least one gas and a sensor for positioning the measuring assembly; and

[0003] - successive measurements of data representative of contents of at least one gas along the measurement path.

[0004] The gas to be measured is, for example, a greenhouse gas such as methane or carbon dioxide or an atmospheric gas such as hydrogen.

[0005] Concerns about environmental protection have contributed to the strengthening of legislation on polluting emissions, particularly in Europe.

[0006] As a result, industrial units, such as those present in the oil or chemical industry, must adapt to increasingly demanding environmental constraints.

[0007] In particular, greenhouse gases are emitted during operations of exploitation, transport, refining, and deposition of hydrocarbons. These emissions are monitored by operators and are regularly subject to reduction measures.

[0008] It is particularly necessary to characterize what the sources of greenhouse gases are and what the quantities emitted by these sources are in order to ensure their control and report the progress made.

[0009] However, the identification of greenhouse gas emission sources and the quantification of diffuse and fugitive emissions are not entirely satisfactory.

[0010] Indeed, emissions are very difficult to measure, because they are often not channeled and result from leaks, and potentially near basins or lakes or in inaccessible places, for example at height or in the middle of the unit.

[0011] Even if it is possible to detect the general area in which an emission source is located, it is sometimes difficult to locate it more precisely within a multitude of equipment.

[0012] Gas content detection devices are implemented on the ground to allow an operator or a robot to carry out measurements on site. However, these devices are generally not very precise and / or give a limited number of measurements.

[0013] An aim of the invention is to provide a measuring method making it possible to locate very precisely a source of gas emission in a ground installation and / or to quantify more accurately the flow of gas emitted by this source.

[0014] To this end, the invention relates to a method of the aforementioned type, characterized by, before moving on the ground, a reversible disassembly of the measuring assembly from a drone for measuring data representative of contents of at least one gas, and / or after moving on the ground, a reversible reassembly of the measuring assembly on a drone for measuring data representative of contents of at least one gas.

[0015] The method according to the invention may comprise one or more of the following characteristics, taken in isolation or in any technically possible combination:

[0016] - the sensor for measuring the representative data comprises at least one cell of open measurement in the atmosphere, each measurement comprising, for the or each measuring cell, the injection into the measuring cell of a first laser beam at a first wavelength characteristic of a first gas to be detected by at least one first laser source and the capture by a detector of a first measurement signal coming from the measuring cell and resulting from the injection of the first laser beam into the measuring cell;

[0017] - it includes the measurement of geographic position data of the set of measurement along the measurement path by the positioning sensor together with successive measurements of data representative of contents of at least one gas;

[0018] - the measuring assembly is equipped with at least one wind, temperature and temperature measuring sensor temperature, pressure and / or humidity, the method comprising measuring wind, temperature, pressure and / or humidity data along the ground measurement path;

[0019] - the frequency of successive measurements of data representative of water contents at least one gas along the ground measurement path is greater than 1 Hz, in particular between 10 Hz and 100 Hz;

[0020] - the measuring assembly comprises at least one battery carried by the support, the method comprising the autonomous power supply of the sensor for measuring data representative of contents of at least one gas and of the sensor for positioning the measuring assembly by the battery along the measuring path;

[0021] - the measuring assembly comprises a data collection unit, the method comprising storing the representative data measured along the measurement path in the data collection unit, and / or the measurement assembly comprises a remote transmission system, the method comprising the remote transmission of the representative data measured and stored in the data collection unit along the measurement path on the ground;

[0022] - it includes the establishment, by an electronic mapping system, of a map of contents of at least one gas along the measurement path, and the detection, on the map, of at least one source of emission of the at least one gas;

[0023] - the measurement path is implemented in an industrial installation comprising equipment, the method comprising loading by the mapping system a map of the geographical positioning of the equipment in the industrial installation and superimposing the map of contents of the at least one gas along the measurement route on the map of the geographical positioning of the equipment in the industrial installation;

[0024] - the map of contents of at least one gas along the measurement path and the map of geographical positioning of equipment in the industrial installation are three-dimensional maps;

[0025] - it includes before the reversible disassembly, a flight of the drone carrying the assembly of measurement in a measurement volume above an area of ​​interest on the ground, and prior successive measurements of data representative of contents of at least one gas in the measurement volume, the method advantageously comprising the establishment of at least part of the measurement path on the ground in the area of ​​interest from the representative data obtained during the prior successive measurements;

[0026] - it includes after the reversible reassembly, a flight of the drone carrying the assembly of measurement in a measurement volume following an in-flight measurement trajectory, and subsequent successive measurements of data representative of contents of at least one gas on the in-flight measurement trajectory, the method advantageously comprising establishing the in-flight measurement trajectory from the representative data obtained during the successive measurements along the ground measurement path;

[0027] - the movement on the ground of the operator and / or the robot is carried out at a speed average between 1 km / h and 30 km / h;

[0028] - ground movement is carried out by the operator on foot or using a vehicle on the ground, especially a motor vehicle or bicycle.

[0029] The invention also relates to a drone for measuring data representative of the contents of at least one gas present in the atmosphere on the ground, comprising:

[0030] - a box;

[0031] - at least one propulsion member, configured to move the housing in the atmosphere, away from the ground;

[0032] - a measuring assembly carried by the housing, the measuring assembly comprising a support, and, carried by the support, a sensor for measuring data representative of contents of at least one gas and a sensor for positioning the measuring assembly, configured to carry out successive measurements of data representative of contents in at least one gas along a ground measurement path, characterized in that the measurement assembly is reversibly removable from a configuration mounted on the housing to a configuration removed from the housing, the measurement assembly being configured in the configuration removed from the housing to be movable on the ground by an operator and / or by a robot and to be able to carry out successive measurements of data representative of contents of at least one gas along a ground measurement path without being connected to the housing.

[0033] The invention also relates to a measuring assembly comprising a drone as defined above and a device for holding the measuring assembly on an operator and / or a robot, the measuring assembly in the configuration disassembled from the housing being configured to be mounted reversibly on the holding device.

[0034] The invention will be better understood on reading the following description, given solely by way of example, and made with reference to the appended drawings, in which:

[0035] - [Fig.l] [Fig.l] is a schematic top view of an industrial installation in which the position of an emission source is determined by means of a measuring method according to the invention;

[0036] - [Fig.2] [Fig.2] is a view of a drone equipped with a measuring assembly reversibly mountable, intended for implementing the method according to the invention;

[0037] - [Fig.3] [Fig.3] is a view of the measuring assembly in its configuration disassembled from the drone case;

[0038] - [Fig.4] [Fig.4] is a view of the measuring assembly of [Fig.3], mounted on a holding device worn by an operator for implementing a measurement path in the method according to the invention;

[0039] - [Fig.5] [Fig.5] is a view of an example of a measurement trajectory followed by the drone in flight, when the measuring assembly is in its configuration mounted on the drone housing; and

[0040] - [Fig.6] [Fig.6] is a schematic view illustrating the implementation steps of an example of a method according to the invention.

[0041] A first measurement kit 6 according to the invention is illustrated by figures 2 and 4. The measurement kit 6 comprises a drone 10, visible in [Fig.2], equipped with a removable measurement assembly 16, intended to measure data representative of contents of at least one gas during a flight of the drone 10 following a measurement trajectory 130 shown in [Fig.5].

[0042] The measuring assembly 16 further advantageously comprises a device 8 for holding the measuring assembly 16 on an operator and / or a robot, visible in [Fig. 4], to carry out measurements on the ground following a measurement path 132 visible in [Fig. 1], before or after the flight of the drone 10. The movement on the ground is carried out by the operator on foot or using a ground vehicle, in particular a motor vehicle or a bicycle,

[0043] The representative data are for example measured with respect to an industrial installation 110, such as an oil installation, in particular an installation for exploitation, transport, refining, treatment or depot of hydrocarbons.

[0044] The gas(es) whose content is measured are preferably methane and carbon dioxide or, alternatively, hydrogen.

[0045] In variants, other gases are measurable, such as aromatic gases, in particular benzene, or butadiene, ethane, carbon monoxide. More generally, the measured content is that of a set of volatile organic compounds (or "VOCs") to determine a footprint of these compounds.

[0046] A gas is measurable if it has a defined spectral signature, for example in the infrared (in particular for wavelengths between 700 nm and 2 pm) or in the ultraviolet (in particular for wavelengths between 10 nm and 380 nm).

[0047] The drone 10 is intended to move in the atmosphere above and around the installation 110 to carry out at various points in the atmosphere above and around the installation 110, measurements of data representative of the contents of at least one gas, preferably of at least two gases.

[0048] As illustrated in [Fig.2], the drone 10 comprises a housing 12, a propulsion assembly 14, suitable for allowing the housing 12 to take off away from the ground, and its movement while flying in the atmosphere above the ground.

[0049] The drone 10 further comprises the measuring assembly 16 which is reversibly removable relative to the housing 12, between a configuration mounted on the housing 12 and a configuration removed from the housing 12. In the mounted configuration, the measuring assembly 16 is for example positioned under the housing 12.

[0050] With reference to [Fig.2], the propulsion assembly 14 comprises a plurality of propulsion members 18, which are here propellers driven in rotation by a motor.

[0051] The propulsion assembly 14 further comprises an energy source 20 formed here by a battery and a system 22 for locating and controlling the movement of the drone 10 in the atmosphere.

[0052] In this example, the drone 10 is a multi-rotor rotary wing drone. It has no wings, its lift being provided by the propulsion assembly 14.

[0053] The drone 10 is for example a rotary-wing quadcopter drone, in particular a DJI M300 drone marketed by the company DU.

[0054] The propulsion members 18 are here propellers rotating around substantially vertical axes. By “substantially vertical”, it is generally meant that the axes of rotation of the propellers are inclined by less than 20° relative to the vertical.

[0055] When the propeller motors are electrically powered by the battery, the propellers are rotated around their axis, causing a downward air flow, which is capable of partially sweeping the housing 12.

[0056] The location and control system 22 comprises a position sensor, in particular a GPS and / or an inertial unit. It further comprises a control unit, capable of controlling the movement of the drone 10 along a trajectory pre-recorded before the flight and loaded into the system 22, or remotely and manually via a remote control.

[0057] The drone 10 is thus capable of automatically following a predefined trajectory, or alternatively, of being piloted manually by an operator.

[0058] With reference to [Fig. 3], the measuring assembly 16 comprises a support 24 carrying a sensor 26 for measuring data representative of the contents of at least one gas, mounted on the support 24, advantageously via dampers 27. It further comprises sensors 28, 29 for measuring temperature and pressure and advantageously, an altitude sensor 30. It comprises a position sensor 30A intended to indicate the geographical position of the measuring assembly 16 during its measurement path 132 on the ground in the configuration removed from the housing 12.

[0059] The measuring assembly 16 further comprises, carried by the support 24, a control system 31, a remote transmission system 31A and a battery 33 intended to ensure the electrical autonomy of the measuring assembly 16 when it is removed from the casing 12 of the drone 10 to be received on the holding device 8.

[0060] The support 24 here comprises an openwork frame, formed of members 32. In the example shown in [Fig.2], the frame is rectangular in shape. It has members 32 along the sides of a rectangle, and members 32 along the diagonals of the rectangle.

[0061] The members 32 are for example made of polymer, to lighten the measuring assembly 16. The polymer is for example chosen from polyetheretherketone, poly(acrylonitrile butadiene styrene), poly(polylactic acid), poly(acrylonitrile styrene acrylate).

[0062] As illustrated in [Fig.2], the members 32 of the frame define a first region 34 for supporting the control system 31, and a second region 36 for supporting the or each measurement sensor 26, offset relative to the first region 34.

[0063] With reference to Figures 2 and 3, the representative data measurement sensor 26 comprises a measurement cell 50 open to the atmosphere, at least one first laser source 52, intended for the detection of a first gas, and possibly, a second laser source 54, intended for the detection of a second gas. It comprises, for the or each laser source 52, 54, a detector 56A, 56B intended to receive the signals allowing the detection respectively of the first gas and the second gas (or a common detector), the signals coming respectively from the first source 52 and the second source 54.

[0064] The sensor 26 further advantageously comprises heat exchange plates 58 mounted respectively on each source 52, 54 and on each detector 56A, 56B.

[0065] The measuring cell 50 is here a single cell for measuring in the same volume the data representative of the contents of the first gas and possibly of the second gas.

[0066] The measuring cell 50 comprises two facing supports 60A, 60B, and connecting bars 62 connecting the supports 60A, 60B. The measuring cell 50 further comprises facing mirrors 64A, 64B, carried respectively by the supports 60A, 60B, the mirrors 64A, 64B delimiting between them a measuring cavity 66.

[0067] In this example, the supports 60A, 60B are mounted parallel to each other, perpendicular to a longitudinal axis A-A' of the measuring cavity 66. The axis A-A' is preferably horizontal when the measuring assembly 16 rests on a horizontal plane support.

[0068] The supports 60A, 60B here have a prismatic shape and a polygonal, preferably square, outer contour.

[0069] The connecting bars 62 fix the distance between the supports 60A, 60B. In this example, the connecting bars 62 extend between the vertices of the polygon defining the outline of the supports 60A, 60B. They extend parallel to each other, delimiting intermediate passage spaces.

[0070] The measuring cavity 66 is therefore open in at least one direction, preferably in at least two directions, between the facing supports 60A, 60B and between the connecting bars 62.

[0071] The length of the measuring cavity 66, taken between the supports 60A, 60B is for example less than 50 cm and in particular between 5 cm and 20 cm.

[0072] The length of the measuring cavity 66 is adapted according to the range of contents expected for the gas to be measured. For example, the length of the measuring cavity 66 is greater if the gas is in trace amounts and / or if its response to the measured wavelength is low. On the contrary, the length of the measuring cavity 66 is less important if the gas to be measured is present with a relatively high content or if its response to the measured wavelength is strong.

[0073] The mirrors 64A, 64B are each mounted respectively on a support 60A, 60B to be placed opposite each other. The mirrors 64A, 64B are concave, with their concavities opposite each other.

[0074] A first support 60A and a first mirror 64A comprise at least one hole, here two holes 68, 70 to respectively allow the injection of a first beam coming from the first laser source 52 and possibly, from a second beam coming from the second laser source 54.

[0075] The second mirror 64B opposite the first mirror 64A, and the second support 64B comprise at least one hole (not visible) for signal extraction, to allow each detector 56A, 56B to receive a signal from the measuring cavity 66.

[0076] The first laser source 52 and the second laser source 54 when present, are mounted on one face of the first support 60A, outside the measuring cavity 66, on either side of the longitudinal axis A-A' of the cavity.

[0077] Each source 52, 54 comprises a laser component 74 and a temperature control element 76, for example a Peltier element.

[0078] The laser component 74 of the first source 52 is for example capable of emitting a first laser beam centered on a first wavelength AL. The laser component 74 of the second source 54 is capable of emitting a second laser beam centered on a second wavelength A2, distinct from the wavelength AL.

[0079] The wavelengths A1, A2 are preferably advantageously separated by at least 5 nm, in particular by at least 100 nm.

[0080] For example, for the detection of methane, the first source 52 is capable of emitting the first laser beam centered on the wavelength Al between 3230 nm and 3250 nm, in particular between 3238 nm and 3242 nm.

[0081] For the detection of carbon dioxide, the second source 54, when present, is suitable for example for emitting the second laser beam centered on the wavelength A2 between 4210 nm and 4250 nm, in particular between 4225 nm and 4235 nm.

[0082] More generally, the wavelength associated with a target molecule is chosen according to the spectral signature of each target molecule and any interfering molecules. The selection of the wavelength depends on the measurement environment (pressure, temperature, concentration of target and interfering molecules, etc.).

[0083] In the example just described, each laser component of the first laser source 52 and the second laser source 54 is for example a laser diode. A laser diode is an optoelectronic component made from semiconductor materials. It emits coherent monochromatic light. It is for example formed from a semiconductor junction, which has three characteristic zones: an n-type confinement layer, an active zone and a p-type confinement layer. The diode is for example a distributed feedback diode.

[0084] As indicated above, the measuring cell 50 operates by direct absorption of laser light in the measuring cavity 66, in contact with the gases whose content is at measure. It is therefore a 50 measuring cell for performing direct laser absorption spectroscopy (Direct Laser Absorption Spectrometry in English).

[0085] The measuring cavity 66 makes it possible to carry out multiple reflections of the laser beams injected from the first source 52 or from the second source 54 to increase the length of the optical path. The measuring cell is thus a multi-pass spectroscopic cell, or Herriott cell.

[0086] The temperature control element 76 is suitable for stabilizing the temperature of the sources 52, 54. In the example shown in the figures, the heat exchange plates 58 are mounted at the rear of the first laser source 52 of the second laser source 54 and of the detectors 56A, 56, in thermal contact with the temperature control elements 76.

[0087] The heat exchange plates 58 are formed of metal, for example aluminum. They protrude relative to the sources 52, 54, to be swept by the air flow generated by the propulsion members 18 during the rotation of the propellers.

[0088] Thus, the calories taken by the temperature control element 76 are evacuated using the heat exchange plates 58, without it being necessary to mount an additional fan to control the temperature of the sources 52, 54 or the detectors 56A, 56B. This lightens the drone 10.

[0089] Each detector 56A, 56B is capable of detecting the intensity of a signal extracted from the measuring cavity 66 respectively at wavelengths including the wavelength A1 of the emission beam of the first laser source 52 and, where appropriate, the wavelength A2 of the emission beam of the second laser source 54.

[0090] Thus, the measured intensity can be related to the incident intensity by the Beer-Lambert law as described below:

[0091] I = 10 exp(LNK)

[0092] where I is the measured intensity, lo is the incident intensity, L is the length of the optical path traveled in the measuring cell 50, N is the number of molecules of the gas studied in the path and K is the absorption coefficient of this gas.

[0093] The dampers 27, when present, comprise spring wires 80 connecting the support 24 to each of the supports 60A, 60B of the measuring cell 50. These spring wires 80 are capable of partially absorbing the vibrations of the propulsion assembly 14 and of the movement in the air of the drone 10.

[0094] The temperature measuring sensor 28 is arranged between the facing supports 60A, 60B. The sensor 28 is for example a thermistor, or a thermocouple, suitable for measuring an electrical resistance of a metallic element which varies according to the temperature.

[0095] The pressure measurement sensor 29 comprises, for example, a pressure measurement tube opening into the measurement cavity 66.

[0096] The presence of a temperature measurement sensor 28 and a pressure measurement sensor 29 directly within the measurement cell 50, preferably in the measurement cavity 66, reinforces the reliability of the data collected, in particular taking into account the low concentration of the gases to be measured in the measurement cavity 66.

[0097] The altitude sensor 30, when present, comprises an altimeter, provided for example with a laser pointing towards the ground to measure the height at which the drone 10 is located.

[0098] The position measurement sensor 30A is for example a GPS sensor, an inertial unit, or a hybrid GPS-inertial unit sensor.

[0099] The control system 31 comprises a unit 90 for selectively supplying electricity to each of the sources 52, 54, a unit 92 for collecting data measured by each detector 56A, 56B and at least one heat exchanger 94, capable of discharging the heat generated by the units 90, 92 without their own ventilation. These units are housed in a housing 96.

[0100] The electrical power supply unit 90 is capable of selectively and successively supplying the first laser source 52 and, where appropriate, the second laser source 54 to obtain a first phase of illumination of the measurement cavity 66 exclusively by the first laser source 52, without illumination by another laser source such as the second laser source 54, then a second phase of illumination of the measurement cavity 66 exclusively by the second laser source 54, without illumination by another laser source, in particular by the first laser source 52.

[0101] Thus, successive measurement phases of data representative of the first content of a first gas, and of the second content of a second gas, can be carried out in the same measurement cavity 66 of the measurement cell 50.

[0102] The electrical power supply unit 90 is for example connected to the energy source 20 of the propulsion member 18 when the measuring assembly 16 is mounted on the housing 12 of the drone 10 or to the battery 33, when the measuring assembly 16 is removed from the housing 12.

[0103] The data collection unit 92 comprises at least one memory, suitable for storing the light intensity spectra as a function of the wavelength recorded at different times by each detector 56A, 56B.

[0104] The data are stored for example at a frequency greater than 1 Hz, in particular between 10 Hz and 100 Hz, on the ground or in flight, whatever the configuration of the measuring assembly 16 relative to the housing 12. The stored spectra preferably comprise a number of points greater than 256, and for example between 256 and 2696 points.

[0105] Thus, a very good resolution is obtained to determine the intensity of the peaks measured in the measuring cell 50 as a function of the wavelength, which allows to deduce contents from it, even if these contents are very low.

[0106] The data collection unit 92 is connected to the remote transmission system 31A to enable the data to be exported to a ground reception station, during the flight of the drone or during a ground measurement campaign, at a frequency which may be lower than the acquisition frequency, for example between 1 Hz and 5 Hz.

[0107] The heat exchanger 94 is in thermal contact with each of the power supply units 90 and data collection units 92. It is capable of discharging the heat produced by these units 90, 92.

[0108] The heat exchanger 94 is capable of being swept by the air flow generated by the propulsion members 18, to evacuate the heat produced by the units 90, 92. Thus no fan is necessary in the housing 96 to cool the units 90, 92, which reduces the weight and the electrical consumption of the drone 10.

[0109] The remote transmission system 31A comprises a transmitter, capable of transmitting data to a ground station, this data being for example the data collected by the unit 92 or a fraction of this data.

[0110] The ground station preferably comprises at least one computer, comprising in particular at least one processor and a memory comprising software modules capable of being executed by the processor to execute functions.

[0111] The calculator thus preferably comprises at least one module for calculating the contents of the or each gas at each geographical measurement position from the data collected by the unit 92.

[0112] It possibly includes a module for calculating a flow of each gas emitted by the or each source from the data collected by the unit 92.

[0113] The calculator advantageously comprises a module for determining a positioning zone of the or each source of emission of a gas, from the data collected by the unit 92 and a model of dispersion of gas coming from a source, in order to determine potential zones of an industrial installation 110 where a source of emission of a gas may be located.

[0114] It optionally comprises a module for determining a route to be taken on the ground capable of determining at least certain sections of a route to be taken on the ground with the measuring assembly 16, using the positioning zone(s) determined by the positioning zone determination module.

[0115] According to the invention, the measuring assembly 16 is reversibly removable between a configuration mounted on the housing 12, visible in [Fig. 2], and a configuration removed from the housing 12, visible in [Fig. 3], for example by means of one or more mechanical and / or electrical connectors arranged on the housing 12 and / or on the support 24 of the measuring assembly 16.

[0116] In the example shown in [Fig.2], the support 24 comprises at least one side upright 100, preferably two side uprights 100 projecting upwards to attach reversibly to connectors 102 provided on the housing 12 and occupy its configuration mounted on the housing 12.

[0117] In the disassembled configuration of the housing 12, the support 24 is configured to be reversibly fixed to the holding device 8, to be carried and manipulated by an operator and / or a robot on the ground.

[0118] For this purpose, in the example of [Fig. 4], the holding device 8 comprises a harness 104 provided with straps 106 configured to attach reversibly to the support 24, in particular to the uprights of the support 24. An operator is thus able to put on the harness 104, then to attach the straps 106 to the support 24 to carry the support 24 using the harness 104 and move it on the ground on foot, by bicycle or in a motor vehicle.

[0119] The anchor points of the straps 106 are thus configured to allow the use of the same straps as those of a remote control of the drone 10, used when the measuring assembly 16 is carried by the drone 10. Thus,

[0120] In one embodiment (not shown), the holding device 8 comprises a handle intended to be mounted under the measuring assembly 16, advantageously by being fixed to a mechanical connection system to a landing gear of the drone 10.

[0121] A first method for measuring the contents of at least one gas present in the atmosphere, preferably with regard to an industrial installation 110, with a view to detecting and quantifying a source 112 of gas within the installation 110 will now be described, with reference to [Fig.6].

[0122] This first method comprises a phase 200 of in-flight measurements via the measuring assembly 16 in its mounted configuration carried by the drone 10, followed by a phase 202 of ground measurements via the same measuring assembly 16 in its configuration dismantled from the drone 10 and carried by an operator and / or a robot using the holding device 8.

[0123] The in-flight measurement phase 200 is intended to identify and quantify a flow of at least one gas measured by the measurement assembly 16, the or each gas being present in a plume emitted from at least one source 112 within the installation 110.

[0124] The ground measurement phase 202 is intended to more precisely identify the position of the source 112 within the installation.

[0125] Initially, in step 204, to carry out the in-flight measurement phase, the measurement assembly 16 is mounted on the housing 12 of the drone 10.

[0126] In step 206, the drone 10 is then put into flight. The propulsion members 18 are activated by the location and control system 22 to allow the drone 10 to take off and move towards the area where the measurements are to be carried out.

[0127] The propulsion members 18 generate a lift force. The loca system The system 22 controls the movement of the drone 10, either under the effect of a remote manual command or by following an automatic program loaded into the system 22.

[0128] During the flight of the drone 10, at step 208, measurements are carried out along a measurement trajectory 130, an example of which is given in [Fig.5].

[0129] In the example of [Fig.5], the measurement trajectory 130 follows, for example, a creeping ladder movement, as illustrated by [Fig.5].

[0130] The drone 10 moves along a plurality of lines 150 parallel to a first direction D1, with a connection segment 152 between each pair of adjacent parallel lines 150. The connection segment 152 takes place along a second direction D2 transverse to the first direction DL

[0131] Here, the first direction D1 is a horizontal direction and the second direction D2 is a vertical direction.

[0132] In this example, all the parallel lines 150 swept by the drone 10 extend substantially in the same vertical measurement plane Pm.

[0133] The extent El of the lines 150 along the first direction Dl is chosen as a function of the width of the plume emitted by the source, to sweep the entire plume 16. This extent El is generally greater than 20 m and is between 20 m and 500 m.

[0134] The distance between the lines 50 is defined by an extent E2 of the connection segments 52 along the second direction. This extent E2 is for example greater than 1 m and in particular between 1 m and 50 m.

[0135] The position, extent and orientation of the measurement trajectory 130 are for example determined from an assumed position of the source 112 and the direction of the wind, as for example described in French patent application No. 22 12559 of the Applicant.

[0136] When the drone 10 moves along the measurement trajectory 130, the representative data measurement sensor 26, the temperature measurement sensor 28, the pressure measurement sensor 29 and possibly the altitude sensor 30 when it is present, are activated successively, advantageously at the measurement frequency described above.

[0137] The measurements by the different sensors 26, 28, 29, 30 are carried out during the movement of the drone 10, without having to immobilize the drone 10. The frequency of the measurements is advantageously greater than 1 Hz, in particular between 10 Hz and 100 Hz.

[0138] For this purpose, the electrical power supply unit 90 selectively and successively supplies the first laser source 52, then the second laser source 54, when it is present.

[0139] Advantageously, during each activation phase of the first laser source 52, the laser component 74 of the second laser source 54 is deactivated. The laser component 74 of the first laser source 52 emits a first laser beam at the wavelength Al which is injected via the injection hole 68 into the measuring cavity 66.

[0140] As indicated above, the thickness of the first laser beam is greater than 1 mm, and in particular between 3 mm and 6 mm. This makes it possible to avoid measurement artifacts that may be created by particles suspended in the measurement cavity 66.

[0141] The first laser beam is reflected successively on the mirrors 64A, 64B, moving back and forth in the measuring cavity 66 to increase the length of the optical path L.

[0142] A first signal is collected through the sampling hole, resulting from the first beam emitted by the first source 52.

[0143] This first signal is captured by the detector 56A and the data captured by the detector 56A is sent to the data collection unit 92 to be stored.

[0144] Then, if necessary, in each activation phase of the second laser source 54, the laser component 74 of the first source 52 is deactivated. The laser component 74 of the second source 54 emits a second laser beam at the wavelength A2 distinct from the wavelength AL. This laser beam is introduced via the injection hole 70 into the measuring cavity 66.

[0145] As previously, the thickness of the second laser beam is greater than 1 mm, and in particular between 3 mm and 6 mm.

[0146] The second laser beam is reflected successively on the mirrors 64A, 64B, moving back and forth in the measuring cavity 66 to increase the length of the optical path L.

[0147] A second signal is collected through the sampling hole 72 resulting from the second beam thus emitted by the second source 54. This second signal is picked up by the detector 56B and the data picked up by the detector 56B is sent to the data collection unit 92 to be stored.

[0148] The measurements being carried out successively make it possible to determine light intensities at two wavelengths A1, A2, representative of the content of a first gas and possibly of the content of a second gas.

[0149] When the drone 10 has finished its mission and returns to the ground, the spectra recorded by the detectors 56A, 56B and stored in the memory of the data collection unit 92, are transmitted by the remote transmission system 31A to the ground station.

[0150] In the ground station, these spectra are stored in association with geographical position data of the drone 10 measured by the location and control system 22, with the temperature and pressure measured by the sensors 28, 29, possibly with the altitude measured by the altitude sensor 30 and with the time at which the measurement was taken.

[0151] The ground station computer calculates the contents of each gas at each measurement point from the representative data measured by the drone 10 along the measurement trajectory. It then implements a method for calculating a flow of the or each gas emitted by the source 14 into the atmosphere, from the contents of each gas in the atmosphere measured by the drone 10.

[0152] Examples of flow calculation methods are given in WO2021204941 or in WO2021234017.

[0153] In a variant, the drone 10 comprises a calculation unit (not shown) embedded on the support 24. The calculation unit is capable of processing the data collected by the detector 56A, 56B at each instant, in particular the light intensity spectra measured at each instant, to calculate contents of the or each gas at different instants, from the representative data collected by each detector 56A, 56B and from a prior calibration.

[0154] The data remote transmission system 20 is then capable of transmitting the content values ​​calculated by the calculation unit, replacing the light intensity data spectra, which reduces the transmission of data in real time and makes it possible to obtain more measurements of the contents of the or each gas in real time. The ground station then collects the contents of each gas calculated by the on-board calculation unit.

[0155] When it has traveled the measurement trajectory, the drone 10 is landed.

[0156] In the first method according to the invention, when the trajectory of the drone 10 determines a flow of at least one unwanted gas in the atmosphere from the installation 110, the measuring assembly 16 is dismantled from the housing 12 to move into its dismantled configuration, at step 210.

[0157] It is then mounted on the holding device 8, in order to be carried by an operator and / or a robot on the ground. As illustrated by [Fig.l], the operator and / or the robot then moves on the ground while searching for the emission source 112.

[0158] In step 212, the operator and / or the robot follows a measurement path 132 on the ground which scans the equipment 114 of the installation. Advantageously, at least certain sections of the measurement path 132 on the ground are determined beforehand by the path determination module of the computer of the ground station, from the data obtained in flight by the drone 10.

[0159] For example, the measurement path 132 is determined to pass in the vicinity of one or each positioning zone of the or each gas emission source. Each positioning zone is determined from the data measured during the flight of the drone 10, collected by the unit 92, using for example dispersion models.

[0160] During the measurement path 132 on the ground, in step 214, the representative data measurement sensor 26, the temperature measurement sensor 28, the pressure measurement sensor 29, the position measurement sensor 30A and possibly the altitude sensor 30 when it is present, are activated successively.

[0161] The frequency of measurement of data on the ground is the same as in flight, for example greater than 1 Hz and in particular between 10 Hz and 100 Hz.

[0162] The battery 33 of the measuring assembly 16 provides the electrical power supply to each of the sensors 26, 28, 29, 30 and 30A, so that they provide data.

[0163] The frequency of the data collected on the ground being very high, this ensures effective detection of the emission zones, or even of the or each individual source 112 directly on the ground, in addition to the measurements obtained by the drone 10.

[0164] The movement on the ground of the operator and / or the robot is carried out at an average speed of between 1 km / h and 30 km / h.

[0165] When the operator is moving on foot, his average speed when taking measurements is generally between 1 km / h and 5 km / h. When he is moving by bicycle, his average speed when taking measurements is generally between 5 km / h and 15 km / h. When he is moving by motor vehicle, his average speed when taking measurements is generally between 15 km / h and 30 km / h.

[0166] Advantageously, at least the representative data measurement sensor 26 is positioned upwind of the operator, in order to limit interference with the gases emitted by the operator (in particular carbon dioxide, methane and water).

[0167] Thanks to the high data measurement frequency, advantageously greater than 1 Hz, in particular between 10 Hz and 100 Hz, it is not necessary to specifically target an area on the ground to find the source 112, but a wide scan by the measuring assembly 16 carried by the operator and / or the robot, coupled with the very high acquisition frequency, ensures detection of the potential sources 112 of gas emitted by the installation 110.

[0168] It is thus possible to locate areas of interest following a campaign to quantify emissions using the drone 10. This then makes it possible to find the location of the sources of gas emissions more precisely, and then to define the action plan for reducing the emissions of these gases.

[0169] Thanks to the presence of the position sensor 30A on the measuring assembly 16, it is also possible to have very precise access to the horizontal position of the measuring assembly 16.

[0170] Thus, after the measuring assembly 16 has carried out measurements along the measuring path 132 on the ground, the measured data are advantageously supplied to an electronic mapping system, for example present within the computer of the ground station, to determine a map of contents of at least one gas along the measurement path 132, and to position, on the map, at least one source 112 of emission of the at least one gas.

[0171] This includes the loading by the mapping system of a map of the geographical positioning of the equipment 114 in the industrial installation 110 and the superposition of the map of contents of at least one gas along the measurement path 132 on the map of the geographical positioning of the equipment in the installation 112.

[0172] The map of contents of at least one gas along the measurement path 132 and the map of geographical positioning of the equipment in the industrial installation 110 are advantageously three-dimensional maps.

[0173] In a variant, an anemometric measurement sensor is present on the measurement assembly 16. It is thus possible to carry out, at each measurement instant, a wind measurement to allow a more precise location of the source. The anemometric measurement sensor is configured to measure the direction and / or the speed of the wind. This makes it possible in particular to pinpoint a location of a source during the measurement.

[0174] The anemometric measurement sensor is for example fixed to the measurement assembly via a removable connection, in particular via a support tube mounted on a quick fixing point.

[0175] The speed and / or wind data measured at each point can further be transmitted to the mapping system and included synchronously as an overlay on the geographic positioning map and / or the content map.

[0176] When an anemometric measurement sensor is present, it is also preferably positioned upwind of the operator. This allows the direction of the wind arriving at the sensor to be reflected.

[0177] In a second method according to the invention, the measuring assembly 16 is first dismantled from the casing 12 of the drone 10.

[0178] The ground measurement path 132 as described in [Fig.l] is initially carried out using the measurement assembly 16 in its disassembled configuration, as described previously.

[0179] Then, if a source 112 of gas emission is detected on the ground, the same measuring assembly 16 is switched to its configuration mounted on the housing of the drone 12.

[0180] A measurement trajectory 130 is then defined for the drone 10 on the basis of the position of the source 112, obtained from the content data measured during the path 132 of the measurement assembly 16 on the ground. This is done for example by orienting the plane of the measurement trajectory 130 and the assumed distance to the source 112 from the content data measured on the ground, and possibly from a wind measurement, as described for example in French patent application No. 22 12559 of the De- lady.

[0181] Then, the propulsion assembly 14 of the drone 10 is activated so that the drone 10 carries out the measurement trajectory 130 in flight and collects data.

[0182] The content measurements obtained along the measurement trajectory 130 are then used to determine the gas flow emitted by the source 112.

[0183] Examples of flow calculation methods are given in WO2021204941 or in WO2021234017.

[0184] Carrying out a ground measurement campaign before a flight measurement campaign makes it possible to concentrate quantification flights, which are costly to prepare and require authorizations, only on the areas of interest. Furthermore, the ground measurement campaign makes it possible to carry out these flights on all detectable sources within a site.

[0185] In another variant, the measuring assembly 16 comprises several measuring cells 50, of a structure similar to the measuring cell 50 described above, each being dedicated to the detection of at least two distinct gases.

Claims

Claims

1. Method for measuring data representative of contents of at least one gas present on the ground, comprising the following step: - movement on a measurement path (132) on the ground, of an operator and / or a robot carrying a measuring assembly (16) comprising a support (24), and, carried by the support (24), a sensor (26) for measuring data representative of contents of the at least one gas and a positioning sensor (30A) of the measuring assembly (16), and - successive measurements of data representative of contents of the at least one gas along the measurement path (132), characterized by: - ​​before movement on the ground, reversible disassembly of the measuring assembly (16) from a drone (10) for measuring data representative of contents of at least one gas, and / or after movement on the ground, reversible reassembly of the measuring assembly (16) on a drone (10) for measuring data representative of contents of at least one gas.

2. Method according to claim 1, in which the representative data measurement sensor (26) comprises at least one measurement cell (50) open to the atmosphere, each measurement comprising, for the or each measurement cell (50), the injection into the measurement cell (50) of a first laser beam at a first wavelength characteristic of a first gas to be detected by at least one first laser source (52) and the capture by a detector (56A) of a first measurement signal coming from the measurement cell (50) and resulting from the injection of the first laser beam into the measurement cell (50).

3. Method according to claim 1 or 2, comprising the measurement of geographical position data of the measuring assembly (16) along the measuring path (132) by the positioning sensor (30A) together with the successive measurements of data representative of contents of the at least one gas.

4. A method according to any one of the preceding claims, wherein the measuring assembly (16) is equipped with at least one sensor (28, 29) for measuring wind, temperature, pressure and / or humidity, the method comprising measuring wind, temperature, pressure and / or humidity data along the measuring path (132) on the ground.

5. A method according to any preceding claim, in in which the frequency of successive measurements of data representative of contents of at least one gas along the measurement path (132) on the ground is greater than 1 Hz, in particular between 10 Hz and 100 Hz.

6. Method according to any one of the preceding claims, in which the measuring assembly (16) comprises at least one battery (33) carried by the support (24), the method comprising the autonomous power supply of the measurement sensor with data representative of contents of the at least one gas (26) and of the positioning sensor (30A) of the measuring assembly (16) by the battery (33) along the measurement path (132).

7. A method according to any one of the preceding claims, wherein the measuring assembly (16) comprises a data collection unit (92), the method comprising storing the representative data measured along the measuring path (132) in the data collection unit (92), and / or wherein the measuring assembly (16) comprises a remote transmission system (31 A), the method comprising remote transmission of the representative data measured and stored in the data collection unit (92) along the measuring path (132) to the ground.

8. Method according to any one of the preceding claims, comprising establishing, by an electronic mapping system, a map of contents of the at least one gas along the measurement path (132), and detecting, on the map, at least one source (112) of emission of the at least one gas.

9. Method according to claim 8, in which the measurement path (132) is implemented in an industrial installation (110) comprising equipment (114), the method comprising the loading by the mapping system of a map of geographical positioning of the equipment (114) in the industrial installation (110) and the superpositioning of the map of contents of the at least one gas along the measurement path (132) on the map of geographical positioning of the equipment (114) in the industrial installation (110).

10. Method according to claim 9, in which the map of contents of the at least one gas along the measurement path and the map of geographical positioning of the equipment (114) in the industrial installation (110) are three-dimensional maps.

11. A method according to any preceding claim, comprising before the reversible disassembly, a flight of the drone (10) carrying the measuring assembly (16) in a measuring volume above an area of ​​interest on the ground, and prior successive measurements of data representative of contents of the at least one gas in the measuring volume, the method advantageously comprising the establishment of at least part of the measuring path (132) on the ground in the area of ​​interest from the representative data obtained during the prior successive measurements.

12. Method according to any one of the preceding claims, comprising after the reversible reassembly, a flight of the drone (10) carrying the measurement assembly (16) in a measurement volume following an in-flight measurement trajectory (130), and subsequent successive measurements of data representative of contents of the at least one gas on the in-flight measurement trajectory (130), the method advantageously comprising the establishment of the in-flight measurement trajectory (130) from the representative data obtained during the successive measurements along the measurement path (132) on the ground.

13. Method according to any one of the preceding claims in which the movement on the ground of the operator and / or the robot is carried out at an average speed of between 1 km / h and 30 km / h.

14. A method according to claim 13, wherein the ground movement is performed by the operator on foot or using a ground vehicle, in particular a motor vehicle or a bicycle.

15. Drone (10) for measuring data representative of contents of at least one gas present in the atmosphere on the ground, comprising: - a housing (12); - at least one propulsion member (18), configured to move the housing (12) in the atmosphere, away from the ground; - a measuring assembly (16) carried by the housing (12), the measuring assembly (16) comprising a support (24), and, carried by the support (24), a sensor (26) for measuring data representative of contents of the at least one gas and a positioning sensor (30A) of the measuring assembly (16), configured to carry out successive measurements of data representative of contents of the at least one gas along a measurement path (132) on the ground, characterized in that the measuring assembly (16) is reversibly removable from a configuration mounted on the housing (12) to a configuration removed from the housing (12), the measuring assembly (16) being configured in the disassembled configuration of the housing (12) to be movable on the ground by an operator and / or by a robot and to be able to carry out successive measurements of data representative of contents of at least one gas along a measurement path (132) on the ground without being connected to the housing (12).

16. Measuring kit (6), comprising a drone (10) according to claim 15 and a holding device (8) for the measuring assembly (16) on an operator and / or a robot, the measuring assembly (16) in the configuration disassembled from the housing being configured to be reversibly mounted on the holding device (8).

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