FR3086545A1 - PREVENTION AND INTERVENTION SYSTEM FOR FIREFIGHTING AND METHOD OF IMPLEMENTING SUCH A SYSTEM - Google Patents

Abstract

The invention relates to a system for securing an area, a central station being in communication link with drones where each drone comprises: - a fire detection unit comprising at least one thermal camera, - an intervention unit on a fire comprising at least one container retaining a gas capable of combining with oxygen to suppress a fire and - a control module comprising a scanning module (MB) of a part (ZS1) of the zone, memorized by the drone, as a function of which a scanning trajectory is calculated, the control module controlling a trigger of the intervention unit during a fire detection and reporting, to the central station, a fire alert comprising at least one piece of information of location.

Description

PREVENTION AND INTERVENTION SYSTEM FOR FIRE FIGHTING AND METHOD OF IMPLEMENTING SUCH A SYSTEM

TECHNICAL FIELD OF THE INVENTION

The technical field of the invention is that of fire prevention and intervention systems. The field relates in particular to mobile firefighting intervention equipment.

TECHNOLOGICAL BACKGROUND OF THE INVENTION

Document DE102016212645 proposes a fire intervention system which combines a fire alarm system comprising a central unit and a plurality of detectors, with a drone. The triggering of a detector sends an alert to the central unit which then sends the drone a set signal comprising an intervention zone and a reference fire state. The drone, while moving to the presumed place of the fire, performs checks by its detection means before triggering an extinguishing action. The drone may in particular comprise a container equipped with a dispersion nozzle for releasing, on fire, an extinguishing agent such as water, foam or carbon dioxide. We understand that such a drone makes it possible to avoid untimely triggering of fire-fighting measures.

SUMMARY OF THE INVENTION

The present invention aims to further improve the responsiveness of existing fire systems.

This objective is achieved by a zone security system, the security system comprising a central station in communication link with drones, each drone comprising at least one localization unit in the zone and a propulsion unit controlled by a trajectory control unit, characterized in that each drone comprises:

- a fire detection unit comprising at least one thermal camera,

a fire intervention unit comprising at least one container retaining a gas capable of combining with oxygen to suppress a fire, this gas being liberable by an opening for expelling the container under the action of a trigger and

a control module comprising a module for scanning a part of the area, memorized by the drone, as a function of which a scanning trajectory for this part of the area is calculated and transmitted to the trajectory control unit, the control module controlling the triggering of the intervention unit during a fire detection by the fire detection unit and the control module going back to the central station, in the event of fire detection, a fire alert including at least drone location information provided by the location unit.

According to a feature of the invention, the station includes a module for distributing drones in the monitored area, this distribution module sending an initialization or an update in memory of each drone, of the part assigned to them.

According to another feature of the invention, in each drone, the control module comprises an alert management module carrying out monitoring of the alerts transmitted by the central station, each alert being associated with an intervention location, the management of alerts calculating a progression trajectory towards localization, as a function of the intervention localization and as a function of the location of the drone, this trajectory being transmitted to the trajectory control unit, the central station comprising a management module alerts for escalation and allocation of each geo-localized alert to one or more drones supporting the drone that issued the fire alert.

According to another feature of the invention, the central station is in communication link with fire detection units each associated with a determined location, these fire detection units being able to send geo-localized alerts to the central station .

According to another feature of the invention, the gas capable of combining with oxygen to smother the fire preferably combines with the hot oxygen molecules, the result of the combination of the gas with the oxygen occurring under the form of a gas harmless to human beings, the gas capable of combining with oxygen to smother the fire being stored in solid form and sublimating in contact with air by promoting its expulsion.

According to another feature of the invention, in each drone, the control unit associates each trigger activation of each container with a memorized duration time delay corresponding to the duration of action of each container, the control unit triggering at minus a second trigger from a second container in the case where the fire detection unit sends a signal representative of a detected fire at the end of the time delay associated with the container previously triggered.

According to another particular feature of the invention, in each drone, the control unit stores the number of containers available, this number being decremented on each new release and transmitted to the central station.

According to another feature of the invention, each extinguisher drone comprises an obstacle detector module in communication with the control unit, the obstacle detector module calculating a new trajectory as a function of the current trajectory and as a function of a solid obstacle detected or as a function of an obstacle corresponding to a space in which the temperature exceeds a maximum memorized threshold.

According to another particular feature of the invention, each drone comprises an anemometer and a module for determining the force and the direction of the wind, the control unit further comprising a module for determining the intervention position from the data provided by the wind strength and direction determination module.

Another object of the invention relates to a method of implementing a security system according to the invention, characterized in that it comprises:

- a scanning step by each extinguisher drone of a part of the monitored area;

- a step of detecting the presence of a fire by the fire detection unit of an extinguisher drone;

- a step of intervention by the extinguisher drone and transmission of its position to the central station.

According to another feature of the invention, the method comprises:

- a step of reception, by the central station, of the geo-localized alert,

- a step of selection, by the central station, of at least one drone coming in reinforcement of the drone having issued the alert

- a step of transmission to said drone coming in reinforcement, of the geolocalized alert,

- a step of receiving the geo-localized alert by the drone coming in for reinforcement and of determining a progression trajectory towards a location corresponding to the geo-localized alert.

According to another feature of the invention, each drone sends to the central station an information message representative of the number of operational containers, each time a new container is triggered.

According to another particular feature of the invention, the method comprises a step of initialization or updating, in memory of each drone, data representative of their part of the area to be scanned.

The invention advantageously provides an automated prevention and intervention system for fighting fires. The reactivity time is improved in particular due to decision-making by the drone, whether rolling or flying, and the fact of diffusing a gas combining with oxygen atoms to smother the fire. Extinguishing drones can, for example, broadcast the entire contents of a cartridge held by an arm and oriented towards fire. A flying drone can also drop a cartridge into or near the fire.

Advantageously, the fire-fighting system according to the present invention is capable of intervening in fires which have not been detected by the central unit. Thus, if the detector closest to the fire is defective or if the communication between this detector and the central unit or between the central unit and the drone is broken, the drone can still intervene in the area where the fire is declared.

Advantageously still, the fire-fighting system according to the present invention makes it possible to improve the efficiency and the reactivity of the existing central system, even in the case for example where the detectors of the centralized surveillance system are not sensitive enough or not numerous enough to cover the entire site, thus preventing certain fires from going undetected or being detected only at an advanced stage.

Advantageously, the fire-fighting system according to the present invention allows intervention at an early stage while ensuring the safety of personnel.

Thanks to the invention, an existing alarm system comprising alarm triggering devices is coupled to a central station and to fire extinguisher drones carrying out both prevention and intervention operations. Each fire extinguisher drone can be assigned to a part of the monitored area that it sweeps regularly. Thus, if a fire occurs during the scanning phase of the extinguisher drone, it is already on site and can directly intervene in the fire, without waiting for instructions from the central station. Fire extinguisher drones can therefore reinforce a detection system and make it possible to detect fires even in the event of a deficiency in alarm detection devices. In addition, fire extinguisher drones can also communicate directly with each other to overcome the limits of the telecommunications network. The system of the invention is therefore a system that is both preventive and reactive, which makes it possible to improve intervention times compared to systems of the prior art.

The invention and its various applications will be better understood on reading the description which follows and on examining the figures which accompany it.

BRIEF DESCRIPTION OF THE FIGURES

The following figures are presented by way of illustrative and non-limiting examples of the invention:

- Figure 1a shows a schematic representation of an exemplary system of the invention;

- Figure 1b shows a schematic representation of an example of an extinguisher drone according to the invention;

- Figure 2 shows a schematic example of the division into parts of the surveillance zones of a site to be protected;

- Figure 3 shows a flowchart of an exemplary method according to the invention;

- Figure 4 shows an example of a drone comprising an on-board control unit according to the invention;

- Figure 5 shows a schematic example of an on-board control unit as illustrated in Figure 4;

- Figure 6 shows an example of implementation of a detection and avoidance function;

- Figure 7 shows an example of implementation of a secure landing function;

- Figure 8 shows an example of implementation of a surface tracking function;

- Figures 9a and 9b each show an example of the route of an area of interest;

- Figure 10 shows a schematic example of a drone according to the invention comprising in particular an on-board control unit and an autopilot module;

- Figure 11 shows in detail an example of flight sequencing in the case of the implementation of a secure landing function;

- Figure 12 shows a schematic example of a drone system according to the invention;

- Figure 13 illustrates an example of a scheduled mission flight plan.

DETAILED DESCRIPTION OF AT LEAST ONE EMBODIMENT OF THE INVENTION

Unless otherwise specified, the same element appearing in different figures has a unique reference.

The SY security system is both a preventive system, that is to say surveillance for fire detection and a reactive system, that is to say rapid intervention on detected fires.

The objective of the intervention may be to extinguish the fire, especially if it is early, or to contain the fire before reinforcements arrive, especially if the fire is widespread.

The site to be protected can be indoors, that is, it can be a closed building like a factory or warehouse, or outdoors, that is, it can be an outside perimeter, like a perimeter around a factory. The site can also be mixed, that is to say include at least one building and a perimeter around the building (s).

The SY system can advantageously supplement a pre-existing fire alarm system on the site to be protected, comprising at least one DA alarm triggering device. DA alarm triggering devices can be manual, such as a push button, or automatic, such as a smoke detector or a heat detector.

The SY system, illustrated in FIG. 1a, comprises a central station SS connected to the DA alarm triggering devices of the fire alarm system. The central station SS receives an alert from a trigger device DA when it has tripped. In FIG. 1a, the central station SS is connected to several DA alarm triggering devices.

The SY security system also includes DR fire extinguisher drones.

DR fire extinguisher drones are unmanned vehicles. DR fire extinguisher drones can be aircraft or land vehicles. These fire extinguisher drones can therefore be flying or rolling or have several modes of mobility including, for example, a flying mode and a rolling mode.

Thanks to their autonomy, fire extinguisher drones can make decisions without receiving instructions from an operator.

The DR fire extinguisher drones, for example of the aircraft type, comprise a control unit UC.

“Control unit” is understood to mean a data processing device comprising for example a processor or other calculation bodies and one or more memories storing, for example, program data, drivers, also known in English as drivers, or data representative of the environment from one or more sensors.

The UC control unit, for example, records and processes data such as mission data and data from sensors. The mission data correspond to the mission assigned to the drone. The control unit addressing commands to the autopilot of the control unit allows the control unit in particular to modify its current mission to adapt to its environment. . The control unit UC carries out, for example, the execution of programs which can call on subroutines to perform functions and sub-functions for processing the stored data.

A functional module is for example composed of one or more functions or sub-functions carried out by one or more programs or sub-programs and executed by one of several calculation bodies, the execution data being stored temporarily or permanently. The control unit UC thus comprises modules which can perform functions and which can communicate with one another so as to be able to cooperate.

Each DR fire extinguisher drone is for example assigned to a ZS part of the monitored area.

As shown by way of example in FIG. 2, each part of the monitored zone ZS comprises at least one fire extinguisher drone DR and at least one device for triggering an alarm DA.

In FIG. 2, the monitored area is divided into five parts of monitoring areas ZS1, ZS2, ZS3, ZS4 and ZS5 of variable sizes. The surveillance zone part ZS1 thus comprises two DR fire extinguishing drones and a DA alarm triggering device, the surveillance zone part ZS2 comprises a DR fire extinguisher drone and a DA alarm triggering device, the surveillance zone part ZS3 has a DR fire extinguisher drone and two DA alarm triggering devices, the surveillance zone part ZS4 has a DR fire extinguisher drone and two DA alarm triggering devices and the surveillance zone part ZS5 has a DR fire extinguisher device and a DA alarm triggering device.

The number of DR fire extinguisher drones and the number of DA alarm triggering devices in a given part of the ZS surveillance zone may for example depend on the area of the part of the ZS surveillance zone or on the probability that a fire declares itself in this part ZS. Indeed, a part of the ZS surveillance zone comprising a toxic products processing unit has a higher probability of a fire breaking out than a part of the surveillance zone comprising an administrative building.

In FIG. 2, the parts of the surveillance zone ZS cover the entire surveillance zone corresponding to the site to be protected. However, it is possible that certain areas of the site to be protected are intentionally not covered, for example an area with an oven or a forge.

It is also possible to envisage memorization by each drone of geographical zones corresponding to zones for which the fire detection thresholds are raised.

It is also possible to envisage carrying out a fire detection as a function of the temperature gradients or of the distribution of the hot zones detected, in comparison with the stored information corresponding to the locations of obstacles or ovens.

In FIG. 1 a, the system SY comprises three drones fire extinguishers DR. Each DR fire extinguisher is capable of communicating with the central station SS. Drones may also be able to communicate directly with each other.

A telecommunications network is for example a mesh network or mesh network according to Anglo-Saxon terminology. “Mesh network” means a network having a topology in which all the hosts are connected peer to peer without a central hierarchy.

A telecommunications network is for example a radio frequency communication network, for example of the Bluetooth or WiFi type.

Several telecommunications networks can also overlap.

The telecommunications network makes it possible in particular to exchange alerts or update or initialization signals between the central station SS and the DR fire extinguisher drones. Thus the central station allows centralization of information and coordination between drones.

The central station SS is thus configured to receive signals from the DR fire extinguisher drones when these detect a fire when scanning their part of the surveillance zone ZS. The central station can also receive alerts, via a wired network, from DA alarm triggering devices. Each alert relating to a fire detection or fire departure is associated with geographic location data.

When a signal comes from a DR fire extinguisher drone, it is for example associated with a PI intervention position which is the position of the fire that the DR fire extinguisher drone has detected. The alert is thus geo-located.

The position of the alert can also correspond to the position of the drone. Advantageously, the autonomy of the drones allows them to detect a fire or a fire starting from an approximate location. The alarm triggering devices generally transmit an approximate position, this geo-localized alert being able to be operated by a drone coming in reinforcement, the geo-localized alert being previously assigned to it by the central station.

The drone with a fire detection module can also provide a precise location of the fire calculated in relation to its current position.

When an alert comes from a DA alarm triggering device, the central station can also associate an intervention zone with it, this zone then being scanned by the drone to which the alert is assigned. For example, if it is a detector, it only detects consequences of the fire such as a rise in temperature or the presence of smoke and if it is an alarm button. Such an alarm only alerts to the presence of a fire nearby. The alert can thus be associated with an intervention zone ZI. This intervention zone will be established near the DA alarm triggering device.

The intervention zone ZI is therefore part of the zone corresponding to the site to be protected. This intervention area can have a size that depends on the type of DA alarm triggering devices and on the general distribution of all the DA alarm triggering devices. An ZI intervention zone may have overlapping parts with the parts of zones assigned to other drones. The drones thus reinforce or supplement the fire surveillance of a system comprising alarm triggering devices.

When a drone receives a geo-localized alert in the form of an intervention zone, its control module will perform a scan of this intervention zone ZI in order to precisely locate the fire or the start of fire before to intervene on the fire.

The drone can also report a false alert to the central station.

The drone can also determine an intervention position, for example depending on the strength and direction of the wind, before intervening on the fire.

The central station SS is also configured to process the alert or the alarm signal and transmit the alert or the alarm signal to at least one DR fire extinguisher. The processing can notably consist in the selection of one or more DR fire extinguisher drones, depending for example on the position of the DR fire extinguisher drones in relation to the PI intervention position associated with the alert or in relation to the area d ZI intervention associated with the alarm signal or depending on the availability of DR fire extinguisher drones. The transmission of the alert or the alarm signal to the DR extinguisher drones allows them in particular to determine a trajectory to go to the intervention position PI or to go to the intervention zone ZI and scan it to locate the 'fire. A scan can also be performed by going to the intervention position. A scan can also be performed around the intervention position.

A DR extinguisher drone, illustrated in FIG. 1b, comprises at least one container RA containing a diffusible extinguishing agent and at least one trigger DE configured for, when activated, to carry out an action on the reserve of diffusing agent RA.

The reserve of diffusible extinguishing agent RA is for example in the form of a cartridge of cylindrical shape closed by a plug. The cap is for example capable of melting from a certain temperature.

The diffusible extinguishing agent can be contained in the reserve of RA extinguishing agent in solid, liquid or gaseous form. It may or may not be under pressure.

The diffusible extinguishing agent is for example in the form of a gas stored in the solid state and sublimates in contact with air. The expelled gas combines with the oxygen molecules to smother the fire. The gas is preferably a gas attracted by the hot gas molecules.

The gas is preferably of a type which does not cause material damage to the elements with which it comes into contact because the result of the combination is predominantly in gaseous form. In addition, the gas expelled and the result of the combination with oxygen is preferably not harmful to human health. Thus drones are not limited in their interventions since even in the event of a false alarm, the diffusion of the extinguishing agent has no other consequence than the reduction of the reserves of diffusible extinguishing agent RA of the drone extinguisher DR. The DR extinguisher drone is thus programmed to intervene early as soon as a fire or the start of a fire is detected. The drone also gains in autonomy compared to the central station SS.

The cartridge used comprises for example a reserve of determined volume in which is stored a compound in the solid state intended to pass directly to the gaseous state in contact with air. Sublimation facilitates expulsion in a directional jet. The expulsion time until exhaustion of the extinguishing agent is for example between 50s and 150s. The weight of the cartridge is for example between 300g and 450g. Such a container can for example be loaded on an unmanned aircraft. One to twenty containers are, for example, loaded on an aircraft. For land drones, the number of containers can be further increased.

For the distribution of the extinguishing agent, a container is for example held by a mobile arm of the drone or fixed to the DR extinguisher drone, its contents being thus released on the fire according to the positioning of the drone. The expulsion orifice is for example closed by a cover intended to be destroyed or another type of plug intended to be removed for the expulsion of the agent. The cover is for example intended to be melted under the effect of a primer.

A container can also be dropped directly onto the fire or into a nearby area. The plug can be removed before dropping or in the case, for example, of a wax plug, the latter can melt directly under the effect of temperature.

Each DR fire extinguisher includes at least one UP propulsion unit and one UT trajectory control unit configured to control the UP propulsion unit so as to obtain a determined trajectory. The trajectory control unit of a flying drone includes for example an autopilot module.

Each DR fire extinguisher drone can include an obstacle detector. Thus an object not listed in a topology memorized by the drone and located on a calculated trajectory of the drone can be avoided.

In addition, the UC control unit communicates with the obstacle detection module and can determine a new trajectory when an obstacle is detected on the current trajectory. The control unit UC can then transmit the new trajectory thus determined to the trajectory control unit UT in order to adapt the trajectory of the fire extinguisher drone DR to the presence of the detected obstacle. The autonomy of the drone is thus reinforced, the presence of an obstacle being taken into account automatically.

Each DR extinguisher drone also includes at least one UD fire detection unit performing detection of a fire or the start of a fire by, for example, a thermal camera or other types of thermal sensors or a detector. smoke.

In the event that a DR fire extinguisher goes to an ZI intervention zone, i.e. without knowing the precise location of the fire, one of the aspects to take into account is the risk of seeing the fire extinguisher DR exposed to excessive heat due to a trajectory too close to the flames. In order to avoid degradation which would result from such exposure, the control unit UC can be configured to determine a new trajectory when a space having too high a temperature is detected. This space has, for example, an average temperature above a critical threshold memorized. This ensures that the DR fire extinguisher drone remains at a sufficient distance from the fire, which avoids damaging it.

The control unit UC can also carry out a video and / or thermal acquisition relayed to the central station for verification by a human operator.

Each DR fire extinguisher includes at least one UL location unit such as for example a GPS module. Each drone can also store topology data of the area to be monitored or of a part of the area to be monitored which is allocated to it.

The control unit UC of each fire extinguisher drone DR includes a module for scanning the area of the MB. "Scanning an area" means the action of traversing that area. This scanning module of the area part MB is configured to determine a scanning trajectory so as to cover the whole of this area part by the thermal camera. The scanning trajectory is transmitted to the trajectory control unit UT. The extinguisher drone DR then follows the scanning trajectory which allows it to cover all of its part of the surveillance zone ZS so as to be able to detect there, if necessary, a fire or the start of a fire using its detection unit. UD fire detection.

The control unit UC of each DR fire extinguisher drone also includes a communication module MA with the central station MA. This communication module sends at least one signal representative of an alert and comprising a location. This location is for example the position of the drone or the position of the detected fire calculated by the intervention module from the position of the drone.

Thus, a DR extinguisher drone automatically generates a signal to signal the presence of a fire detected during the scanning of its part of the surveillance zone. A drone sent to the reinforcement zone will thus confirm the position of the fire or the start of the fire or provide additional information on a extent of the fire not initially known.

The control unit UC of each DR fire extinguisher includes an MG alert management module sent by the central station SS. This MG alert management module receives an alert associated with a ZI location or intervention zone. The alert management module then generates a new trajectory for progression towards the detected fire. The drone can perform a sweep to detect the fire or the start of a fire, all along the new trajectory of the drone or near the indicated location, such as in the intervention zone.

The control unit UC of each DR fire extinguisher includes an MS communication management module. This MS communication module receives an alert signal associated with a PI intervention position issued by the central station SS or by another fire extinguisher drone DR.

The alert management module then determines a new trajectory for progression to a PI intervention position. This new trajectory is transmitted to the trajectory control unit UT.

The control unit UC also includes a module for determining the intervention position MP from the measurements of the fire detection unit UD. When the extinguisher drone DR scans its part of the surveillance zone ZS or its intervention zone ZI and its fire detection unit UD detects a fire, the intervention position determination module MP evaluates the position of PI intervention according to the detected position of the fire. An intervention position is determined thanks to all the parameters characterizing a fire in addition to the environmental data relating to wind or relief.

Each DR fire extinguisher includes a thermal camera and a unit for acquiring one or more images. The intervention position determination unit MP can update the intervention position calculated as a function of the thermal images successively generated by the thermal camera. The evolution of the fire is thus taken into account.

The control unit UC of each extinguisher drone DR also includes an intervention module Ml triggering the release of the extinguishing agent from the container in the event of fire detection or the start of a fire.

For DR type aircraft fire extinguisher, the intervention position can be calculated above the fire or the start of the fire. For example, a container is dropped above the fire. The agent's expulsion port may be destroyed before dropping or the container may be dropped directly into the fire, for example in the case of an expulsion port closed by a wax plug.

The trajectory to the release position is for example calculated as a function of a minimum safety altitude. The UP propulsion unit comprises for example one or more rotary wings so as to allow hovering. More generally, the trajectories can be defined more freely and therefore adapted to each intervention situation.

The container can also be held by a drone in the direction of the fire, at a determined distance from the fire.

Thus, the application of the extinguishing agent is done as close to the fire and allows effective action.

During activation of the trigger, the intervention position calculation unit can generate an intervention trajectory such as a circular trajectory around the position of the fire or departure of the fire.

Each DR extinguisher drone preferably comprises a plurality of containers of RA diffusible extinguishing agent. The intervention module M1 can activate the triggers DE associated with the reserves of diffusible extinguishing agent RA simultaneously or successively. This allows in particular to adapt the diffusion of the extinguishing agent to the evolution of the fire.

It is also important to take into account information regarding weather conditions to generate a PI intervention position and in particular the wind speed and direction. Neglecting these parameters can lead to the dispersion of the extinguishing agent next to the fire, the extinguishant being carried by the wind. In order to take this risk into account, each DR fire extinguisher drone may include an anemometer. The intervention position determination module determines an intervention position from the fire and direction position and from the wind speed. Thus, the presence of wind is taken into account in the distribution of the extinguishing agent.

It may also be useful for an operator to be able to follow the intervention of the DR fire extinguisher drone (s) from the SS central station, in particular to assess the fire that triggered the alert. For this, each DR fire extinguisher drone includes for example a camera and a video acquisition unit performing an acquisition and retransmission of a video stream to the central station SS.

The method as shown in FIG. 3 will now be described.

The drone performs a scanning step E1. Each DR extinguisher drone performs a scan of the part of the surveillance zone ZS which is allocated to it and stored in memory.

The scanning step is for example followed by a step E2 of intervention on a fire or a start of fire triggered by a detection of the presence of a fire or start of a fire by the fire detection unit UD of the DR fire extinguisher. The DR extinguisher drone then intervenes directly on the fire, without having received an alert or signal from the central station SS or another DR extinguisher drone.

The scanning step E1 can also be followed by a substep E11 of reception by the central station SS of an alert associated with an intervention zone ZI, coming from an alarm triggering device DA.

After this reception, the central station performs a next substep E12 of processing and transmitting the alert to the DR fire extinguisher drone. The central station selects the drone. The central station, for example, checks the conditions of proximity of the drone in comparison with the other drones, in relation to the location of the alert. The central station also checks the information stored on the drone's capacities and in particular its reserves of extinguishing agent. The alert is then transmitted to the drone.

The drone then performs a sub-step E13 of receiving the alert and determining a trajectory for progression towards the intervention zone ZI.

After determining the new trajectory, the drone performs a substep E14 of transmitting the trajectory to the trajectory control unit UT. The drone thus scans to the indicated location or to the indicated intervention area.

This sub-step is then followed by the intervention step E2 when the fire or start of fire is detected by the drone.

The scanning step E1 can also be followed by a sub-step E111 of reception by the extinguisher drone DR of a signal associated with an intervention position PI and of determining a trajectory for progression towards the position d IP intervention by the alert management module. The alert is transmitted by the central station SS.

We could also consider a geo-localized alert issued by a drone directly in communication with another drone.

During a following substep E121, the drone transmits the trajectory to the trajectory control unit UT. The drone then performs a scan until the location of the alert.

The drone then performs the E2 intervention stage on fire or the start of fire. The drone is for example placed on an area next to the fire and sprays the agent on the fire. The drone also sends its location along with fire detection or fire start information to the central station.

Advantageously, the position transmitted by the drone is updated and provides additional information on the extent of the fire or its progression. In the case of an alert associated with an intervention zone, the position of the drone also provides more precise information to the central station on the location of the fire.

In a next step E3, the central station performs a step of updating the parts of the surveillance zone allocated to each of the drones. Drones not requisitioned by an alert are for example distributed over a remaining area to be monitored. Each drone in scanning mode resets its trajectory according to the new part of the area memorized. This new trajectory can be calculated based on the data acquired by each DR fire extinguisher concerning its environment, for example by means of the obstacle detector, the smoke sensor or the thermal camera.

The method may also include a step E4 of evaluation, by the control unit UC of the extinguisher drone DR, of the presence of a fire at the end of a time delay corresponding to the duration of action of the container. The drone can thus activate another container to continue its intervention on the fire if a present this fire is detected. One or more containers of extinguishing agent can be triggered simultaneously with each intervention.

DR fire extinguisher drones are, for example, in the form of unmanned aircraft, as shown in FIG. 4. Each drone comprises a control unit UC. The control unit UC includes, for example, a data storage and processing UM unit and one or more CE environment sensors.

The UC control unit is installed on a P100 flying platform including an SV flight control system. This control system notably includes an AP autopilot module. A flying platform means the assembly comprising in particular the carrying structure, the thrusters and the flight control system capable of ensuring the stability of the unmanned aircraft during the flight and the execution of flight commands.

The flight control system also includes an autopilot module for executing received flight commands. These commands can relate, for example, to the execution of a movement, a rotation or a trajectory within the flight space provided by the mission. The P100 flying platform is, for example, of the rotary wing or fixed wing type.

As shown in Figure 4 the flying platform can be in the form of a hexacopter. This hexacopter is here from a commercial drone whose radio frequency control module is for example kept as a safety measure, even if a resumption of commands in manual mode by the operator, would only allow to perform maneuvers approximate in comparison to the control sequences which can be carried out by the control unit UC.

The UM data storage and processing unit is a computing device comprising in particular a processor and a memory connected by communication, addressing and control buses, as well as interfaces and communication lines in connection with the system. flight control system SV of the flying platform and in particular with its autopilot. The means for establishing this data link between the control unit and the flight control system can for example be in the form of a link via a USB port.

The AP autopilot module is capable of managing the flight controls of the flying platform. The autopilot module is for example capable of executing direct instructions such as moving from a first point of determined GPS coordinates to a second point of determined GPS coordinates or traversing a given trajectory or even maintaining the flying platform in hovering flight. above a given point. The autopilot can also be configured to execute instructions such as forward, backward or move right or move left, at a specified speed. The autopilot can also be configured to execute instructions such as moving up or down, at a determined speed, or rotating to the right or left.

The SV flight control system may also include:

-a radiofrequency transmitter / receiver, as described above for a resumption of commands directly by the operator for safety,

- a GPS module allowing in particular the execution of flight commands comprising trajectories between determined geographic coordinates,

-an inertial unit also designated by IMU ("Inertial Mass Unit", in English) and

-a camera.

The transceiver allows for example a direct resumption of control by the operator for safety, but is however not absolutely necessary, even if in practice, this radiofrequency transceiver will be kept for additional safety or in a disabled state.

An environment sensor is for example a rangefinder type sensor, namely a sensor capable of measuring one or more distances between the drone D and one or more objects in its environment. Examples of a range finder type environment sensor are a LIDAR, a RADAR or any other range finder type sensor according to English terminology.

By environmental sensor is meant a sensor generating data representative of its environment, such as for example, a sensor capable of measuring one or more distances between the drone and an object in the environment of the drone, a sensor for receiving sound signals. or digital or analog electromagnetic signals, a sensor for receiving light signals. A range finder can for example measure distances along a line of points according to a viewing angle of the sensor. The viewing angle can be arranged for example under the drone or in front of the drone. The rangefinder can also take measurements in different fields of vision all around the drone. The rangefinder is for example of the "range finder" type such as a LIDAR.

Advantageously, the control unit UC is able to use the data from the environment sensor to modify the control of the drone D by transmitting modified commands to the flight control system SV and in particular by giving commands to Flight modified in the AP autopilot module, without the need for an operator acting from a central station. The central station for unmanned aircraft is also referred to as a ground station. In addition, the decisions taken by the control unit UC on the basis of the environmental data supplied by the environment sensor (s) CE allow adaptability to different types of mission. The control unit programmed specifically for a mission can, for example, execute the mission despite certain incomplete data, such as partially known cartographic data.

Examples of missions are for example, the exploration of a disaster area including the search for mobile terminals, with for example in the event of detection, an approach phase to establish a communication link of sufficient quality, then a stationary phase initiating a data exchange with the detected mobile terminal (s). The exchange of data includes, for example, the transmission of information or questions and the waiting for an answer or an acknowledgment of receipt. The search and communication sensor with mobile terminals is for example used in collaboration with a range finder detecting obstacles around the drone in order to stop a search flight or an approach flight in the event of obstacle detection. For example, a fire detected near a mobile terminal will be treated as a priority.

Another example of a mission includes for example a landing in an unknown or ill-defined zone, as described in more detail below. Landing may be necessary to respond to a fire.

Another example of a mission includes, for example, the deposit of a charge, such as a reserve of extinguishing agent, in an unknown or ill-defined geographical area. Such a load can also be a payload comprising itself one or more sensors and means of communication deployed in the field.

UC control unit architecture

FIG. 5 schematically represents an example of architecture of the on-board control unit UC. The on-board control unit UC includes for example its environment sensor CE generating data representative of the environment of the drone stored in memory of the storage and processing unit of UM data. Data collection is managed here by a TC data collection module. The UM data storage and processing unit can also transmit configuration data to the CE environment sensor.

The UM data storage and processing unit, which includes for example a processor and a memory, allows the execution of programs which can call on subroutines to perform functions and subfunction for processing the stored data. A functional module is thus composed of one or more functions or sub-functions performed by one or more programs or sub-programs.

The computer executes in particular stored programs allowing the transmission of flight command sequences to the AP autopilot module. The SF05 module, which performs the autopilot driver function, allows the transmission of command sequences interpretable by the autopilot.

Among the various modules illustrated in a nonlimiting manner in FIG. 5, there are:

- SF04 and SF08 modules for receiving and transmitting data respectively via the communication link with the central station S;

- An obstacle avoidance S&A module for performing an obstacle detection and avoidance type function, also known in English as "Sense and Avoid";

- A landing module SL for the realization of a secure landing also designated in English by "Safe Landing";

-An FS surface tracking module for performing a remote positioning function of a surface and maintaining this distance when the drone is moving, also known in English as "Follow a surface";

- The SF05 driver communication module with the SV flight control system of the platform and in particular with the AP autopilot module.

-The TC module for data collection and in particular the data from the environment sensor or data from the SV flight control system of the flying platform such as positioning data, provided by the IMU and by GPS ,

-The EX module for executing a memorized programmed mission.

The modules shown diagrammatically in FIG. 5 can be electronic modules physically connected in the control unit UM or can be programs or subroutines installed in the memory of the control unit UC.

The SF04 and SF08 communication modules with a central station are used to establish a data link with the central station. Indeed, the accomplishment of a mission by a drone generally requires feedback from the drone, as for example when the mission requires exploration. The central station S can also transmit parameters to modify the mission, in particular as a function of the data generated by the environment sensor.

The obstacle avoidance S&A module avoids unknown obstacles on the initially programmed path or unexpectedly occurring on this path such as moving objects. An example of implementation of the obstacle avoidance module will be described in more detail below.

Advantageously, a drone having complex functions of adaptability to a partially unknown environment or of adaptability to a changing environment can easily be implemented.

The landing module SL allows in particular the modification, discovery, evaluation or selection of the landing location, by the control unit. For example, an originally planned landing location is no longer accessible or the precise landing location may not be determined in advance. An example of implementation of the landing module will be described in more detail below.

The FS surface tracking module allows for example to facilitate the inspection of a building, without knowing precisely the layout of this building. The surface tracking module can also be used to inspect another object of interest or to carry out an approach phase. An example of implementation of the surface tracking module will be described in more detail below.

Advantageously, these functions provide additional autonomy to the drone by allowing it to react to many situations. Thus a drone losing its communication link will be able, for example, to continue its mission or to stop it in a safe way by a secure landing. Functions can be performed alone or in combination.

Complex missions can thus be carried out by the drone which offers increased decision-making autonomy. The complexity of the missions can result for example from uncertainties on the cartographic data of the environment in which the drone operates or on the data relating to targets to be detected or areas to be inspected.

Obstacle avoidance module

An example of detection and avoidance function is illustrated in FIG. 6. The environment sensor can for example be in the form of a LIDAR type sensor installed on the flying platform with its angle of vision towards the before, the data generated by this sensor being used for the detection of obstacles in front of the drone.

The S&A detection and avoidance module uses, for example, several sub-modules. The S&A detection and avoidance module can thus associate, using the TC data collection module, time information or "timestamp" (according to English terminology) stored with each data acquired by the CE environment sensor. Similarly, the S&A detection and avoidance module associates, with the TC data collection module, time information with each positioning datum provided by the AP autopilot module. Associated positioning data includes, for example, data generated by the IMU and data generated by the GPS. In particular, the IMU generates tilt and roll data. The GPS notably generates longitude, latitude and altitude data.

The data collection module TC includes, for example, a sub-module SF01 for writing dated data from the environment sensor and the flight control system into memory.

The stored dated data coming from the environment sensor is then merged, by a fusion sub-module SF02, with the dated positioning data coming from the flight control system. The positioning data includes in particular the inclination provided by the IMU inertial unit.

The metadata thus obtained are then formatted using the correction sub-module SF03, processing the data representative of the environment as a function of the positioning information of the flying platform, so as to obtain more precise information. The correction consists for example in taking into account the inclinations in pitch and in roll of the drone with respect to the horizontal, for example to eliminate zones of obstacles corresponding in fact to a flat horizontal ground lying under the drone but detected from the tilts.

The corrected information shows, for example, the presence of a surface close enough to the drone, in front of the latter, to be considered an obstacle. The detection threshold applied by the S&A avoidance and detection module is for example adjusted as a function of the advance speed of the drone.

Advantageously, the correction sub-module SF03 allows an interpretation of the data collected to assess whether the detected objects constitute real obstacles. Thus a detected object outside the trajectory followed by the drone is not taken into account and does not trigger an avoidance action.

The S&A detection and avoidance module triggers an avoidance action during obstacle detection. The avoidance action includes, for example, stopping and hovering the drone. The avoidance action may also include a modification of the flight control sequences transmitted to the autopilot, notably resulting in a change of direction in order to circumvent the obstacle.

The S&A detection and avoidance module is for example always active and periodically performs, at a determined frequency, verifications of the corrected distances detected with respect to a detection threshold.

In the event of obstacle detection, the detection and avoidance module S&A can also trigger the activation of a mapping sub-module SF06 classifying in memory the corrected information that triggered the obstacle detection. All of this information on detected obstacles associated with geographic positions of the drone can then be used, this data being representative of a map of obstacles. By triggering bypass actions, the drone then constitutes an increasingly rich mapping of obstacles where the obstacle zones are calculated by the drone itself. The S&A detection and avoidance module comprises for example a sub-module SF09 for selecting an action from among several determined avoidance actions.

The decision taken by the sub-module SF09 for selecting the avoidance action may result, for example, in:

-A activation of a sub-module for calculating a new trajectory SF07 comprising as input parameter in particular the obstacle mapping data and transmission of a new sequence of flight commands;

-Emergency stop and hover stabilization, for example for a rotary-wing aircraft type drone;

- A reduction in speed;

- A return to the secure position;

- Sending a request for instructions to the central station.

The determination of a new trajectory, for example involves the transmission of the new flight command sequence to the driver module SF05 in order to be transmitted to the autopilot module AP. The SF05 driver module then formats the commands addressed to the autopilot.

Advantageously, by simply changing the driver module SF05, it is easy to implement the obstacle detection and avoidance function, or another function, for another platform. Another such flying platform comes from a commercial drone, for example.

If the decision made by the sub-module SF09 to select an avoidance action is to stop the flight and put the platform in hovering flight, this instruction is for example transmitted to the autopilot module AP, via the driver module SF05 .

If the decision taken by the sub-module SF09 for selecting an avoidance action is to request instructions from the central station, the request for an instruction request is for example sent to the sending module SF08 to the central station .

On reception of the message from the central station, a reception sub-module SF04 performs for example the reception and addressing of the instructions in the on-board control unit.

The sub-module SF09 for selecting the avoidance action can also trigger several actions simultaneously or sequentially.

Again, the UC control unit and its S&A obstacle avoidance module provide increased range for the drone.

The obstacle avoidance S&A module can also call the sub-module SF08 for processing and sending data, such as data from the CE environment sensor, to the central station.

The on-board processing and storage unit comprises a radio transceiver 70 in communication link with the central station.

Landing module

An example of implementation of the landing module SL is illustrated in FIG. 7. Its purpose is for example to perform, by means of an environment sensor CE such as a LIDAR arranged with its field of vision vertically under the drone , a scan of the destination area of drone D and a search for an acceptable point for landing. The drone lands for example as close to the fire to intervene on it.

The landing module SL comprises, for example, the data collection module TC comprising itself, as described above:

- the sub-module SF01 for writing in memory dated data from the environment sensor and the flight control system,

- the merging SF02 sub-module, with dated positioning data coming for example from the flight control system,

- the SF03 correction sub-module, processing data representative of the environment based on positioning information from the flying platform.

The landing module SL can also include the mapping sub-module SF06. Data representative of an obstacle map can be used but also enriched by data representative of obstacles detected on the ground. Several types of obstacles are for example memorized during the activation of the sub-module SF06 of cartography according to the type and the configuration of the environment sensor (s). A space with an average temperature above a stored critical temperature, for example, will be considered as an obstacle at the same time as a target which should be approached as much as possible.

The map updated by the mapping sub-module SF06 is used by the sub-module SF10 for selecting a landing zone for the drone D. The selection of the point or the landing zone is made on the basis previously determined criteria, such as the need for a relatively small slope, a flat surface with a determined extent of the area or even the absence of mobile obstacles. The obstacle map, for example, shows an extended fixed area for which the sub-module SF10 for selecting a landing area has calculated a slope and an inclination below the acceptable thresholds memorized. The sub-module SF10 for selecting a landing zone then stores the data representative of the geographic positioning of this validated landing zone.

The trajectory calculation sub-module SF07 can then be activated by the landing module SL to determine the trajectory to the memorized validated landing zone.

The flight control sequences up to the validated landing zone, generated by the trajectory calculation sub-module SF07, are then supplied to the command formatting sub-module SF05, the formatted flight control sequences then being transmitted to the AP autopilot.

In the event that the SF10 sub-module for selecting a landing zone cannot determine a valid zone for a safe landing, the drone can perform an exploration action, including enriching the obstacle mapping data .

An SF11 safe landing sub-module can also be activated simultaneously. The safe landing sub-module SF11 triggers, during the loss of altitude, as a function of the data provided by the data collection module TC, an assessment of the landing zone, the accuracy of this assessment s '' increasing as the drone loses altitude. The SF11 safe landing submodule may also include an emergency stop function causing, for example, the drone to stop in hovering flight. The safe landing SF11 sub-module can in particular invalidate the landing zone to trigger the search for a new landing zone.

Surface tracking module

An example of implementation of the FS surface tracking module is illustrated in FIG. 8. Its purpose is, for example, to perform, using an CE environment sensor such as a LIDAR arranged with its field of vision frontally or laterally. compared to the drone, monitoring at height and distance from a substantially vertical area to be covered. The area thus traversed is for example simultaneously analyzed by another analysis sensor or by a camera of the flying platform. The analyzed data thus collected are for example associated with the detected environmental data or with the positioning data generated by the flying platform. A building can thus be analyzed quickly and precisely. It is thus possible to inspect the surface of an object whose arrangement, in particular its external surface and its orientation, is not known in advance. We could also consider tracking a surface on a moving object.

The surface monitoring module FS comprises for example the data collection module TC comprising itself, as described above:

- the sub-module SF01 for writing in memory dated data from the environment sensor and the flight control system,

- the merging SF02 sub-module, with dated positioning data coming for example from the flight control system,

- the SF03 correction sub-module, processing data representative of the environment based on positioning information from the flying platform.

From the data representative of a distance between the drone and the inspected surface, provided by the TC data collection module, a sub-module SF12 for controlling the distance between the drone D and the surface of interest generates flight commands on the one hand to maintain constant this distance and on the other hand to traverse a determined memorized zone. The constant distance from the obstacle is kept within a tolerance threshold, stored in memory. Commands to move in or out, depending on the direction in which measurements are taken, are generated to maintain the desired distance. Furthermore, the area to be inspected can be traversed according to a linear route diagram, a two-dimensional route diagram as shown in FIG. 9a or a three-dimensional route diagram as shown in FIG. 9b.

The two-dimensional path is for example determined by an entry point B95, an exit point E97, an inspection height H99, an inspection step S96 and an inspection width D98 stored.

The three-dimensional path is for example determined by an entry point B92, an exit point E93, an inspection height H94, an inspection width W91, an inspection depth L90 and an inspection step S89 memorized.

The SF12 sub-module is thus adapted to generate flight commands, so as to maintain a substantially constant distance between the drone D and the surface to be inspected while traversing this surface. The adaptation of the mission is then carried out permanently.

The flight commands thus determined are supplied to the SF05 formatting driver sub-module which processes them and transmits them in executable form to the AP autopilot module.

The surface monitoring module FS calls, for example, the sub-module SF08 for formatting data intended for the central station. This SF08 module transfers for example:

-analysis data of the surface generated by an analysis sensor,

- positioning data generated by GPS or IMU - data provided by a thermal camera of the flying platform (P100)

-data provided by the TC module for collecting data generated by the environment sensor (s).

Advantageously, the FS surface inspection module facilitates the implementation of a surface examination. The surface examination is all the more effective as it is based on an increased adaptability of the drone to its environment.

Advantageously still, certain advanced modules use the same sub-modules, which facilitates the implementation of the control unit and facilitates a parallel execution of several modules.

FIG. 10 shows an example of a drone D comprising different hardware components.

The UC on-board control unit includes an CE environment sensor and a UM data storage and processing unit. The on-board control unit UC also includes an energy supply module E.

Drone D includes a P100 flying platform including an autopilot and controlled by the control unit. The flying platform P100 comprising a flight control system SV, in communication with the control unit, and a support structure P as well as a propulsion unit. The propulsion unit includes, for example, drive motors of several propellers.

The flying platform P can be of rotary wing or fixed wing. The flying platform also includes an energy supply module.

In addition to the AP autopilot module, the P100 flying platform includes C flight instruments such as a GPS, an IMU ("Inertial Mass Unit") or a camera, such as a thermal imaging camera.

The P100 flying platform is therefore able to execute flight commands given to it.

The flight control system SV may also include a radio frequency communication module for communicating with a central station, in particular to allow, for security reasons, to take back commands from the central station, as explained above.

Among the environment sensor (s) we find for example:

- rangefinder or "rangefinder" type measuring one or more distances between drone D and an object present in the environment of drone D, or even several rangefinders covering several areas around the drone,

- an optical sensor having characteristics specific to a mission, or even several of these sensors covering several areas around the drone,

- a thermal or infrared detector, or even several of these detectors covering several areas around the drone.

The P100 flying platform also includes a load transport system allowing the dropping of an extinguishing agent cartridge or the deployment in situ of a payload such as a measuring instrument in communication link with the central station .

A D drone can thus drop payloads in different places. Again, this type of complex mission can be carried out on the basis of reasonable technical, human and financial resources.

FIG. 11 illustrates an example of sequencing the flight of the drone D in the case of a landing function. As shown in Figure 11, the flight sequencing performed by the UM control unit gives the drone significant autonomy.

More particularly, FIG. 11 illustrates the relationships between the functions implemented by the control unit UC and the flight phases of the flying platform P100. Among the flight phases are:

- "Transit": movement of the drone D according to a predetermined trajectory;

- “Approach”: the drone is approaching its destination;

- "Still Fligth": hovering until instructions are given to the AP autopilot module.

When approaching the landing zone, the control unit UC can for example carry out an analysis of the landing zone to determine a point suitable for the landing of the drone D. The analysis can for example be a sweeping of the ground carried out using the environment sensor.

If the UC control unit identifies a point that meets the criteria for a safe landing, the UC control unit gives instructions to the AP autopilot module to initiate a landing procedure also known as "Landing".

During this landing phase, the control unit UC can also activate the obstacle avoidance module so as to detect unforeseen obstacles which may come into play in the landing zone. If such an obstacle is detected, the control unit UC can then take the decision to interrupt the landing procedure and return to the base station or seek another landing zone.

If for example during a search phase of a landing zone, no suitable point is detected, the control unit can trigger a search by ground sweep. The control unit can also initiate a return to the base station or its take-off point, after a determined number of unsuccessful attempts to find landing zones. A mode of waiting for instructions from the base station can also be triggered by sending a specific request to the base station.

The UC control unit can also trigger an emergency landing in degraded mode, for example if the drone's Batt battery level is too low. In this degraded mode, the landing zone can be selected, for example according to the inclination and the flatness, but according to greater tolerance thresholds or according to the criterion of the least ailments.

The drone system S comprising the drone D and the central station is also suitable for many missions due to the considerable autonomy of the drone. The mission can for example be continued despite a temporary interruption of data link with the central station. The drone is notably able to trigger actions to re-establish this data link. The mission may also include partially known areas to be explored with feedback to the central station.

FIG. 12 illustrates an example of an S drone system comprising:

- Elements intended for the ground 81;

- The drone D;

- Data transmission means 80;

- Power supply tools 79.

The elements 81 intended for the ground essentially comprise a central station B. The central station B can include power supply means, data processing and storage means, means of communication with the drone.

The base station B makes it possible to recover the information sent by the drone D, including any instruction requests if the control unit UC cannot make a decision. A ground operator can for example use the base station B to send settings to the drone D.

Drone D includes the UC control unit and the P100 flying platform.

The flying platform includes:

-A power supply module E comprising a Batt battery and a PdM power distribution module;

-A SV flight control system comprising a radio communication radio module, a GPS module, an IMU inertial unit, an AP autopilot module, an FLC camera such as a thermal camera;

- A flying platform P comprising a mechanical support structure Str and propulsion means Prop.

The UC control unit includes:

-The UM storage and processing unit for mission data and data from the CE environment sensor;

- One or more CE environment sensors depending on the mission

- A load transport module C,

- A radio communication module for radio frequencies, “ground / onboard communication”.

The FLC camera can be included in the on-board control unit UC or in the flight control unit SV.

The UC control unit thus includes modules allowing it to both interface with the P100 flying platform and to interpret the data acquired in particular by its CE environment sensor (s).

The drone system S, for example, enables complex missions to be carried out autonomously, without requiring operator intervention on the ground.

The data communication means 80 comprise a communication link L established between a ground communication interface GL and a flight communication interface AL. In the present description, this in-flight communication interface is included in the on-board control unit, unless otherwise indicated.

The power supply tools 79 include in particular the batteries of central station B. The on-board control unit is for example supplied with energy by the battery of the flying platform.

FIG. 13 represents an example of a flight plan stored for a given mission. This flight plan is for example initially memorized by the on-board control unit. The flight plan includes, for example, a take-off point P50, a landing point P51 and various waypoints such as P49 and P48. Each point includes its latitude, longitude and altitude. The height is calculated in relation to a cartographic frame of reference. The profile of flight 47 at different heights is also stored. The map is for example presented in the background on the central station, when the flight plan is displayed.

Examples of use cases

Fire intervention type mission

During missions of the fire intervention type, the real environment is generally modified and any mapping of the region used is therefore obsolete. The drone has functions allowing it to adapt to the situation by taking into account, for example, environmental parameters for the execution of its mission.

The drone S can also be configured during the flight, in a simple manner, for example by indicating to it an area to be monitored. For example, the operator identifies a risk area and transmits the coordinates of this area of interest to the drone. The operator communicates with the drone from the central station in communication link with the drone. This simple parameter allows the drone to adapt its mission in real time. Adaptation is in fact largely based on environmental sensors.

During the flight, drone D indeed detects its environment, using an environment sensor, for example a thermal camera, a laser rangefinder or an infrared detector, or using a sensor dedicated to the detection of mobile terminals communicating by radio such as for example in WiFi, Bluetooth, GSM, LTE.

The detected environment can be under the drone, above the drone, in front, behind or on the sides. The detections carried out by the drone are for example memorized and formatted by being associated with a corresponding geographical position before being transmitted to the central station. For example, the operator will have the option of establishing communication with detected cell phones to request information directly from people on site.

For example, the drone returns to its starting point once the surveillance zone is fully covered.

The functions performed by the drone will be for example:

- The detection of lights or the start of lights and the location of their position,

- The use of location data to present a map showing the positions of the lights or the start of fires, this map can be used later by people working on the ground,

- Detect obstacles and their nature, such as landslides, fire zones or flooded areas.

Load deployment type mission

Another example of use case concerns for example the deployment of a charge or the activation of a cartridge.

It appears here that the drone S can take into account its real environment to accomplish its mission without requiring a high precision preliminary location. It is the drone itself which acquires the data on the field of operations in order to land, for example on the roof of a building.

The drone S allows an efficient deployment in a simplified way by landing in an unknown or approximately known area. The effective deployment of a load or the activation of a cartridge of extinguishing agent indeed requires a precise location of the environment and the landing zone.

Drone D when it arrives near a fire location, for example, will detect and find a landing zone with a sufficient level of security.

After landing, drone D activates, for example, the transported load such as one or more cartridges of extinguishing agent.

We can then plan a flight of the drone to its takeoff point or to another point scheduled for its landing.

Toxic gas detection

Another example concerns the detection by drone D of toxic gases forming, for example, a cloud. Some factories have a need to detect toxic clouds that can form from their site of establishment. The drone system makes it possible to carry out this type of mission simply and at low cost. This type of toxic cloud detection can be performed preventively or in the event of an accident on the site.

For example, drone D has a surveillance zone in memory where a toxic cloud is likely to be present. This data representative of a geographic exploration area can be programmed at the same time as the mission or updated in real time by the central station, via an AL communication link established with the drone. The operator can confirm the execution of the mission after acknowledging receipt of an update of the geographic exploration data.

The drone uses for example one or more CE detectors during its flight to assess its environment. The CE environment sensor (s) used are for example optical sensors used to detect opaque smoke or a color specific to a toxic cloud or even sensors for detecting chemical components and in particular toxic gases. Such a probe will for example be kept at a distance from the drone to limit the aerodynamic disturbances generated by the drone. When detecting the elements sought, the data representative of the environment are for example stored in memory, in correspondence with positioning data. The drone's positioning data includes, for example, the latitude, longitude and altitude as well as the inclinations of the drone. The memorization of environmental data is only involved for areas of interest. The control unit can also slow down, or even take short breaks, for a closer look at its surroundings, before resuming a faster pace out of remarkable areas.

If a fire is detected by the drone, the latter then intervenes in the fire.

The detection of a smoke cloud or a heat source can also constitute the detection of an obstacle taken into account by the drone performing an avoidance maneuver.

Claims (13)

1. System (SY) for securing an area, the securing system comprising a central station (SS) in communication link with drones, each drone comprising at least one localization unit (UL) in the area and one unit propulsion (UP) controlled by a trajectory control unit (UT), characterized in that each drone comprises: - a fire detection unit (UD) comprising at least one thermal camera, a fire intervention unit comprising at least one container retaining a gas capable of combining with oxygen to suppress a fire, this gas being liberable by an opening for expelling the container under the action of a trigger and - a control module comprising a scanning module (MB) of a part of the area, memorized by the drone, according to which a scanning trajectory of this part of the area is calculated and transmitted to the control unit trajectory (UT), the control module controlling the trigger of the intervention unit during a fire detection by the fire detection unit and the control module going back to the central station, in case fire detection, a fire alert comprising at least location information of the drone provided by the location unit. 2. Securing system according to claim 1, characterized in that the station comprises a module for distributing drones in the monitored area, this distribution module sending an initialization or an update to the memory of each drone, from the part of the area assigned to them. 3. Security system according to one of the preceding claims, characterized in that in each drone, the control module comprises an alert management module (MG) monitoring the alerts transmitted by the central station, each alert being associated with an intervention location, the alert management module calculating a progression trajectory towards the location, as a function of the intervention location and as a function of the location of the drone, this trajectory being transmitted to the control unit trajectory (UT), the central station comprising a module for managing the alert alerts and allocating each geo-localized alert to one or more drones coming in reinforcement of the drone having issued the fire alert. 4. A security system according to the preceding claim, characterized in that the central station is in communication link with fire detection units each associated with a determined location, these fire detection units being able to raise geo alerts. located towards the central station. 5. Safety system according to one of the preceding claims, characterized in that the gas capable of combining with oxygen to smother the fire preferably combines with the hot oxygen molecules, the result of the combination of the gas with oxygen being in the form of a gas harmless to human beings, the gas capable of combining with oxygen to smother the fire being stored in solid form and sublimating in contact with air by promoting its expulsion. 6. Securing system according to one of the preceding claims, characterized in that in each drone, the control unit associates each trigger activation of each container with a memorized duration timer corresponding to the duration of action of each container , the control unit triggering at least a second trigger of a second container in the case where the fire detection unit (UD) sends a signal representative of a detected fire at the end of the time delay associated with the container previously triggered. 7. Securing system according to one of the preceding claims, characterized in that in each drone, the control unit stores the number of containers available, this number being decremented at each new release and transmitted to the central station. 8. Security system (SY) according to any one of the preceding claims, characterized in that each extinguisher drone (DR) comprises an obstacle detector module in communication with the control unit (UC), the detector module d obstacle calculating a new trajectory as a function of the current trajectory and as a function of a solid obstacle detected or as a function of an obstacle corresponding to a space in which the temperature exceeds a maximum memorized threshold. 9. Securing system (SY) according to one of the preceding claims, characterized in that each drone comprises an anemometer and a module for determining the force and direction of the wind, the control unit further comprising a module determining the intervention position (MP) from the data provided by the wind strength and direction determination module. 10. Method for implementing a security system (SY) according to one of the preceding claims, characterized in that it comprises: - a step (E1) of scanning by each extinguisher drone (DR) of a part of the monitored area; - a step (E2) of detecting the presence of a fire by the fire detection unit (UD) of an extinguisher drone (DR); - a step of intervention by the extinguisher drone and transmission of its position to the central station. 11. Method according to claim 10, characterized in that it comprises: - a step of reception, by the central station, of the geo-localized alert, - a step of selection, by the central station, of at least one drone coming in reinforcement of the drone having issued the alert - a step of transmission to said drone coming in reinforcement, of the geolocalized alert, - a step of receiving the geo-localized alert by the drone coming in for reinforcement and of determining a progression trajectory towards a location corresponding to the geo-localized alert. 12. The method of claim 10 or 11, characterized in that each drone sends to the central station, an information message representative of the number of operational containers, each time a new container is triggered. 13. Method according to one of claims 10 to 12, characterized in that it comprises a step of initialization or updating, in memory of each drone, of the data representative of their part of the area to be scanned.