FR3073942A1 - AMBIENT AIR QUALITY MEASURING UNIT COMPRISING AIR INTAKE HANDLES DESIGNED TO AVOID THE INTRODUCTION OF RAIN, AND ASSOCIATED MEASUREMENT MODULE - Google Patents

Abstract

The invention relates to a measuring box (1) for mounting on a vehicle, comprising a chamber (2) containing at least electronic sensors measuring characteristics of an air flow inside the housing. The chamber (2) is covered with a cover (4) having on the side a plurality of openings (7) of air inlets on the sidewall extending by a straight conduit ending in a wall (8) called "Impactor" forming a plane perpendicular to the direction of the conduit. The bottom of the conduit opens on a first passage along the impactor in the direction of the base of the housing to evacuate by gravity the non-gaseous elements, and on a second passage (9) along the impactor in another direction and giving access to inside the room. The impactor thus stops the water particles by evacuating them by gravity downwards, while the gaseous component of the ambient air runs along the impactor laterally and penetrates inside the housing.

Description

Ambient air quality measurement box with air intake vents designed to prevent the introduction of rain, and associated measurement module

1. Field of the invention

The invention relates to the measurement of ambient air quality using a housing comprising sensors and moving within an area while being mounted on a vehicle. The invention relates more particularly to the fact that the housing has air inlet gills extending inside the housing by a duct, the gills are protected from rain by an impactor placed at the bottom of each duct and discharging non-gaseous particles from below.

2. State of the art

Nowadays, air pollution mapping systems based on sensors installed in fixed stations are known, but the spatial resolution of the service obtained is limited by the density of the stations. Devices on board vehicles are also known comprising means for communicating directly with a remote information system, these devices have sensors for measuring the quality of the ambient air, such as:

a temperature sensor, a humidity sensor, a sensor to measure the density of fine particles in suspension, a sensor of gases such as nitrogen oxides, CO2 and / or CO, ...

These boxes also include a GSM module, a Wifi module and a Bluetooth module, in particular for communicating the measurements made to a remote server. These modules are generally present in the form of specific circuits implemented on a printed circuit comprising a control unit for the management, the processing of the measurements and the transmission of the data. Environmental measurement sensors are designed to be in contact with ambient air and to measure its characteristics, but the other circuits are rather intended to be placed in computers, and not in contact with outside air.

The ambient air can be charged with rain which can distort the measurements and also damage the measurement sensors. The manufacturers recommend that certain sensors be protected from the ambient environment, such as the thermometer, this detector should not be exposed to the sun so as not to be heated by radiation and thus see its functioning disturbed. It is also known for bent conduits leading to an opening which is directed downwards so that heavy particles (rain, snow, polen, dust, ...) do not enter the conduit carried by the air flow. This type of arrangement does not allow easy entry of at least a portion of an ambient air flow, requires creating an air flow using a fan. According to another embodiment, the sensors can be placed in a box closed by a cover whose opening and closing are motorized. At the time of measurement, the cover opens and closes when all the sensors have completed their work. This arrangement is suitable for fixed stations, but not for mobile boxes. Indeed, if it rains and the cover opens, the rain caused by the air flow caused by the movement enters the housing and risks flooding the interior.

To avoid the introduction of raindrops, it is known to reduce the size of the inlet openings, by protecting the opening with a woven element, for example. However, this equipment reduces the exchanges between the interior of the case and the ambient air, thus risking distorting the measurements, preventing the measurement of certain particles in suspension in the air which cannot pass through the tissue, and disturbing the temperature measurement by considerably reducing the ventilation inside the measuring box.

There is therefore a real need for equipment intended to measure the characteristics of the ambient air, which is protected from rain, snow and other bad weather. The realization of the measurement box must remain simple, inexpensive to manufacture and simple assembly allowing easier maintenance and quick cleaning.

3. Statement of the invention

The invention aims to overcome the drawbacks set out above, as well as others which will appear in the rest of this document.

To this end, the subject of the invention is a measurement box intended to be mounted on a vehicle, comprising a chamber containing at least electronic sensors measuring characteristics of an air flow inside the box. The chamber is covered with a cover comprising on each side a plurality of air inlets extending by a straight duct ending in a wall called an “impactor” forming a plane perpendicular to the direction of the duct. The bottom of the conduit leads to a first passage along the impactor in the direction of the base of the housing to evacuate by gravity the non-gaseous elements, and to a second passage along the impactor in another direction and giving access to the interior. from the room.

In this way, the impactor stops the water particles and, by reducing their kinetic energies, evacuates them by gravity at the foot of the impactor without them entering inside the housing. The gaseous component of the ambient air also hits the impactor, but being lighter, it breaks up into a multitude of air flows which enter the chamber along the impactor laterally.

According to a first embodiment, the housing is of rectangular shape and has inlet openings at each corner. These louvers comprise an impactor having a shape which follows that of the corner of the housing and which is extended by a vertical wall disposed perpendicularly to the side of the housing to laterally close said louver, the air entering through said corner louvers passing over the wall vertical to enter the room. In this way, the ambient air animated by the movement of the housing can also enter the room through the corners.

According to another embodiment, the two lateral ends of the impactors of the inlet openings placed at each corner extend to reach a second passage allowing access to the air chamber coming from a side opening of the housing.

According to another embodiment, the vents serve both as an inlet means for the air flow inside the housing and as an outlet means for this air. In this way, the housing can be oriented in various directions relative to that of the wind.

Advantageously, the housing has inside a continuous wall surrounding the printed circuit supporting the sensors and placed behind said impactors. In this way, the box has a second protection in case water particles succeed in crossing the obstacle constituted by the impactors.

According to another aspect, the invention relates to a module for measuring the characteristics of the ambient air comprising a measurement box as described above, and a base intended to be fixed on a vehicle and constituting a bucket for receiving said box. The periphery of this base has a wall extending vertically and surrounding the lower part of the housing while leaving a space allowing an air flow to be inserted.

According to another embodiment, the side turned towards the outside of said wall of the base has a face inclined upwards in the direction of the top part of the housing. In this way, most of the ambient air which is pushed by the wind passes over the shell of the housing and only part of the air flow passes between the wall and the sides of the housing.

According to another embodiment, the upper part of the wall exceeds in height the edge surmounting the top of the air inlet openings. In this way, even if the rain arrives horizontally in front of the side of the housing, it cannot penetrate directly into the duct of the inlet.

4. List of figures

Other characteristics and advantages of the invention will emerge from the description below, provided by way of nonlimiting example, and made with reference to the appended drawings, in which:

- Figure 1 shows a front view, seen in profile and the interior seen on top, of a housing for measuring the quality of the ambient air according to an exemplary embodiment;

- Figure 2 shows the housing on its base seen from above according to a particular embodiment, the whole forming a module for measuring the characteristics of the ambient air;

- Figure 3 shows the housing of the previous figure seen in section, and mounted on its base;

- Figure 4 shows the base shown in the previous figure and seen from above, intended to receive the housing shown in the previous figures;

- Figure 5 shows a view from below the base 3 of the housing 1 shown in the previous figures;

- Figure 6 shows a side view of the housing shown in the previous figures;

- Figure 7 shows a perspective view in section of a detail of the housing and the base shown in the previous figures.

5. Detailed description of the invention

Identical elements in the different figures have the same references.

Fig. 1 shows a front view, seen in profile and the interior seen on top, of a housing for measuring the quality of the ambient air according to an exemplary embodiment.

The profile view presents a housing 1 of substantially planar shape comprising inside a chamber 2 constituted by a base 3 and a flattened upper shell 4. The housing is preferably intended to be fixed to the exterior body of a vehicle, preferably on the roof. The vehicle may be a car, a truck, a transport vehicle, etc. The base 3 and the shell 4 constituting the outer envelope of the housing 1 are preferably made of plastic by molding. The interior of the chamber 2 includes in particular a printed circuit 5 on which integrated circuits and environmental sensors 6 are welded. Among the sensors 6 capable of equipping said box to measure the quality of the ambient air, there may be mentioned:

a temperature sensor, a humidity sensor, a sensor for measuring the quantity of fine particles suspended in the ambient air (these particles having a size of 10 μm maximum), a sensor of gases such as oxides of nitrogen, CO2 and / or CO, ...

According to an improvement, the sensors of the same type are in duplicate on the card, this replica makes it possible to verify their operations. Indeed, if the values provided by the two sensors are too different, then we can suspect that one of them is malfunctioning and a signal is sent to a remote server to report this fact. The electronic card has a microprocessor, which processes the measured values, and a means of communication (Wi-Fi network, Bluetooth or GSM, acronym for Global System Mobile) enabling this data to be sent to a remote server. This means of communication is advantageously a GSM electronic module fixed on the printed circuit.

The housing 1 is advantageously fixed to the outside of a mobile vehicle. The box includes a GNSS module (acronym for "Global Navigation Satellite System") for geolocating the measured data. The box can also use the location information of the different fixed bases of the communication network and operate by triangulation to determine its position. The box 1 is connected to the vehicle battery for the power supply. According to a variant, the housing has a battery inside and is thus perfectly autonomous.

Ambient air enters the chamber through inlet openings 7 and can thus come into contact with the sensors 6. The air flows passing through the chamber are represented by dotted arrows in FIG. 1. By placing the box 1 horizontally on the roof of a vehicle, the air circulates around the box 1 and a part penetrates inside of it by the inlet openings 7. The ambient air spreads into the room and passes to the sensors which can thus make measurements and determine the environmental characteristics.

The housing 1 cannot be completely sealed because the ambient air could not then enter the interior. However, it is subject to bad weather and the presence of water in the housing 1 could damage the sensors 6 or the other components of the electronic card 5.

To prevent water from entering the chamber, the inlet openings form a preferably straight conduit which ends inside the housing by a vertical wall, called an “impactor” 8. The housing is open at the base of this impactor, and at least on one of its sides, a lateral opening 9 is made to give access to the interior of the chamber, as shown by the four arrows in FIG. 1.

In this way, the non-gaseous components, such as rainwater, are stopped by the impactor 8 and are evacuated by gravity at the bottom of the duct delimited by the internal wall 10 and the shell 4 where they are evacuated exterior of the housing, while the gaseous elements enter the chamber through at least one second passage which opens horizontally on the side of the impactor 8. In this way, the non-gaseous components such as rainwater, fall by gravity and are discharged to the bottom of the conduit by a first passage opening at the base of the impactor, while the gaseous elements enter the chamber by at least a second passage which opens horizontally on the side of the impactor.

Advantageously, the openings 7 are arranged on the four sides of the cover 4. In this way, the housing offers no preferred direction relative to the vehicle, any of its four sides can be placed towards the front of the vehicle. However, it is not recommended to place the housing at an angle. The openings 7 have the same structure regardless of the side on which they are arranged, and can be used as air inlet channels in the chamber as well as air outlet channels outside the housing 1 .

The housing 1 can be stowed on the roof of a vehicle, on a gallery bar for example, using a screw and nut system. According to a preferred embodiment, the housing 1 is fixed on a base 10 itself secured to the vehicle and constituting a bucket for receiving the housing. The mechanical connection between the housing 1 and the base allows easy disassembly, during a maintenance operation for example.

Fig. 2 shows the housing 1 on its base 10 seen from above according to a particular embodiment. The mounting of the box on its base constitutes a module for measuring the characteristics of the ambient air. Fig. 2 as well as the following present diagrams of the prototype produced and tested presented as an exemplary embodiment of the present invention. The prototype has a parallelepiped shape whose dimensions are approximately: 11 centimeters on the side and 4 centimeters in height. In this figure, the upper shell 2 of the housing can be seen, showing on its periphery the various air inlet openings 7, and the sides of the base 10 extending all around the housing 1.

Fig. 3 shows the housing 1 of FIG. 2 seen in section and mounted on its base 10. FIG. 2 showing the approximately square shape of the housing and FIG. 3 having a flattened shell 4 with substantially straight sides, illustrate the parallelepiped shape of the housing.

The base 10 has a wall 11 curved inward at its top and surrounding the lower part of the housing. The aerodynamics of the assembly allows most of the air to be directed over the top of the case. A small part of the air is inserted between the wall 11 and the side of the housing 1 and can thus be introduced inside the inlet openings arranged on the sides of the housing. By inserting into this tight space, the air flow loses its speed and the water particles are more easily stopped by the impactors at the bottom of the gills 7. The presence of the wall 11 extending vertically around the housing protects from the rain and limits the ingress of water while allowing air to enter the gills. The path of the gaseous component of the ambient air carried by the movement of the vehicle and passing through the chamber of the housing is shown in this figure. This path is illustrated by two dotted arrows showing the air flow which enters an air intake opening and which exits through another opening on the opposite side.

Advantageously, the upper part of the wall 11 protrudes in height from the ridge surmounting the top of the air intake vents 7. In this way, even if the rain arrives horizontally in front of the flank of the housing, it cannot penetrate directly in the inlet duct.

Fig. 4 shows the base seen from above, the base being intended to receive the housing 1 shown in the preceding figures. The mechanical connection between the housing 1 and the base 10 is clearly visible. The connection is made by slightly rotating the housing with respect to the base, via indexing clips fixed below the housing and fitting into holes 12 placed in the base.

The width of the space between the wall and the edge of the base is of the order of 4 millimeters. This width is large enough to allow the housing to rotate about 10 ° and its separation from the base 10.

Fig. 4 shows the position of an anti-theft mechanical locking system 13 placed at the bottom of the base, this system comprises a latch which is blocked by a locking tab. This tab is pushed back from the latch by the introduction of a specific tool, which makes it possible to release the latch and to remove the housing 1 from its base 10. The latch passes through the plate at the bottom of the base in an oblong cut so as to follow the rotational movement of the housing during its separation. A set of electrical connectors 14 consisting of pins mounted on springs is mounted in the center of the base, which makes it possible to minimize the displacements during the rotation of the housing. These connectors electrically supply the printed circuit 5 of the housing and possibly make a wired connection allowing communication with the control unit. This connector is not used when the unit is autonomous with a battery and on-board radio communication circuits.

Fig.4 also shows elongated orifices 15 for evacuating rainwater or snow which are located below groups of inlet openings 7 when the housing 1 is mounted on the base 10. From in this way, the particles of water flowing from the inlet openings following their contact with the impactors 8, are easily evacuated downwards through sufficiently large orifices. It can also be seen that these orifices (denoted “15 '” in FIG. 4) are also present under the four corners of the housing 1. According to an improvement, air intake openings are also present at the corners of the housing 1.

Fig. 5 shows the base 3 of the housing 1 shown in the preceding figures and seen from below, the two faces shown in FIGS. 4 and 5 being intended to come opposite one another. In this figure, the air intake vents on the side are visible and gathered in the figure in groups 16 highlighted by a rectangle on the sides and a figure in an arc on the corners. Each group 16 of louvers 7 discharges the water downwards using the same elongated discharge orifice 15 visible in the preceding figure. The impactors 8 associated with each hole 7 on the sides of the housing appear at the bottom of each conduit in the form of a black rectangle. The four inlet openings 7 ′ placed at the four corners of the housing also appear. These louvers are characterized by the fact that they have an impactor (not shown in the figure) in the shape of an arc of a circle and that they are not associated with an air intake which is specific to them. Indeed, the two lateral ends of the impactors extend to reach the lateral opening of a hole 7 on the side of the housing. In other words, the inlet openings 7 'placed at the corners of the housing 1 pass through the lateral openings of the side openings 7 to allow the ambient air which runs along the impactors placed at the corners, to enter the housing. This is illustrated by the two dotted arrows representing the paths of the gaseous component of the air which enters a hole 7 ′ of air inlet and which enters the chamber.

Fig. 5 also shows a stop 17 of the tongue of the anti-theft mechanical locking system (referenced 13 in FIG. 4), as well as the indexing clips 18 which are housed in the holes of the base (12 in FIG. 4) . We can also see in this figure, the locations 19 of the screw holes which join the upper shell to the base 3. A central opening is made to give access to the interior of the chamber and thus allow the passage of the electrical connectors 14 visible in the previous figure

Fig. 6 shows a view on the side of the housing (noted 1 in Figs. 2 and 3) shown in the previous figures. The side openings 7 and two corner openings 7 'are clearly visible on the side of the housing. The impactor 20 at the bottom of the corner openings follows the rounded shape of the corner of the housing with a recess and is extended by a vertical wall 21 arranged perpendicular to the side of the housing to laterally close said opening. The air entering through the vents at the four corners of the housing passes over the vertical wall 21 to reach the lateral opening 9 giving access to the chamber, the hearing 7 from the side closest to a corner also using this opening side to give access to the bedroom.

Fig. 7 shows a perspective view in section of a detail of the housing and the base shown in the previous figures. The air flows are represented by dotted arrows, and the water path by an arrow with a solid line. We can see that the upper part of the wall 11 exceeds in height the edge surmounting the top of the air intake vents 7. According to an improvement, the housing 1 comprises a continuous wall 22 surrounding the electronic elements. This wall which is also visible in FIG. 3 is placed behind the impactors 8 and follows the same shape as the sides of the housing. The face turned towards the outside of this wall is extended downwards by water discharge orifices 23. The air entering through the vents passes over this wall through spaces made under the upper shell

4. This wall constitutes a last protection in the event that residual elements (raindrops, water particles, dust, ...) come to pass through the lateral openings 9, these particles would still be blocked by this wall which surrounds the electronic card and plays the role of a dam surrounding the electronic circuits.

Although the present invention has been described with reference to the particular embodiments illustrated, it is in no way limited by these embodiments, but is only limited by the appended claims. In particular, the present invention can be used to measure all the characteristics of a gas present outside or in a room. Note that changes or modifications may be made by the skilled person.

Claims (9)

1. Measuring unit (1) intended to be mounted on a vehicle, comprising a chamber (2) containing at least electronic sensors measuring characteristics of an air flow inside the housing, said chamber (2) being covered with a cover (4) comprising on the side a plurality of gills (7) of air inlets on the side extending by a straight duct ending in a wall (8) called “impactor” forming a plane perpendicular to the direction of the conduit, the bottom of the conduit leads to a first passage along the impactor (8) in the direction of the base of the housing to evacuate by gravity the non-gaseous elements, and to a second passage (9) along the impactor in another direction and giving access to the interior of the chamber. 2. Measuring box (1) according to claim 1, characterized in that the box (1) is of parallelepipedal shape and has inlet openings (7 ') at each corner, these openings comprising an impactor (8) having a shape which follows that of the corner of the housing and which is extended by a vertical wall (21) disposed perpendicularly to the side of the housing to laterally close said opening, the air entering through said corner openings (7 ') passing over the vertical wall (21) to enter the chamber. 3. Measuring unit (1) according to claim 2, characterized in that the two lateral ends of the impactors of the inlet openings (7 ') placed at each corner extend to reach a second passage (9) allowing access to the air chamber from a hole (7) on the side of the housing. 4. Measuring unit (1) according to claim 1, characterized in that the openings (7, 7 ') serve both as an inlet means for the air flow inside the unit as an outlet means for this air. 5. Measuring unit (1) according to any one of the preceding claims, characterized in that it comprises inside a continuous wall (22) surrounding the printed circuit supporting the sensors and placed behind said impactors (8). 6. Module for measuring ambient air characteristics comprising a measurement box (1) according to any one of the preceding claims, and characterized in that it further comprises a base (10) intended to be fixed on the vehicle and constituting a tub for receiving said housing, the periphery of said base having a wall (11) extending vertically and surrounding the lower part of the housing (1) while leaving a space allowing air to be inserted. 7. Measuring module according to claim 6, characterized in that the side facing outward of said wall of the base has a face inclined upwards in the direction of the top part of the housing 1. 8. Measuring module according to claim 6 or 7, characterized in that the upper part of the wall (11) exceeds in height the edge surmounting the top of the air inlet openings (7). 9. Measuring module according to any one of claims 6 to 8, characterized in that the base (10) has elongated orifices for discharging (15) rainwater which are located below groups of '' inlet vents (7) when the housing 1 is mounted on the base (10).