System and method for anti-collision monitoring of an aircraft participating in a formation flight.

Abstract

System and method for collision avoidance monitoring of an aircraft participating in a formation flight. The collision avoidance monitoring system (10) of a follow aircraft (1, 1S) includes electronic circuitry (14) configured to store (30a) an initial power value of a radio frequency signal (22) received from a lead aircraft (1L) and to repeatedly perform the following steps: - receive (30) power level information from the radio frequency signal (22) received from the lead aircraft; - store (33) a value of said power level, called the current power value; - calculate (34) a difference between the current power value and the initial power value; - determine (35) a first risk of collision between the follow aircraft and the lead aircraft if the calculated difference is greater than a power threshold;and - in the event of the determination of the first risk of collision, order (36) the issuance of an alert in the cockpit of the following aircraft and order a disengagement of the following aircraft from the formation flight. Figure for the abbreviation: Fig. 2;

Description

Title of the invention: System and method for anti-collision monitoring of an aircraft participating in a formation flight.

[0001] The invention relates to the field of formation flight. As is known, formation flight of a group of aircraft reduces the overall fuel consumption of the group. In formation flight, a follower aircraft flies close to a vortex generated by the lead aircraft it is following. Thus, the various aircraft participating in a formation flight fly in close proximity to one another. It is important to ensure the safety of the various aircraft participating in the formation flight by preventing any risk of collision between them. All transport aircraft are equipped with a collision avoidance system called TCAS (Traffic Collision Avoidance System). This system is designed to detect a risk of collision between aircraft and to initiate an avoidance maneuver when such a risk is detected.

[0002] During a formation flight, given that the aircraft fly close to each other, it would be interesting to find a solution allowing for redundancy in the anti-collision monitoring of aircraft flying in formation.

[0003] As previously stated, the term "formation flight" is commonly used to refer to a predefined flight geometry in which aircraft fly close to one another. In other circumstances, aircraft may fly in a predefined geometry, for example, when a follow aircraft is expected to fly at a substantially constant distance from a lead aircraft, even if the aircraft are not flying close to one another. Since the invention also allows monitoring of compliance with such a substantially constant distance, in the following description, the term "formation flight" includes the flight of aircraft in a predefined geometry. Description of the invention

[0004] The present invention aims in particular to provide a solution to this problem. It relates to a collision avoidance monitoring system for a follower aircraft participating in a formation flight in which the follower aircraft flies near a vortex generated by a lead aircraft, the monitoring system comprising electronic circuitry integrated into at least one avionics computer of the aircraft, in which the electronic circuitry is configured to implement the following steps:

[0005] - receive activation information for a guidance mode, such as flight in formation of the follow aircraft; and

[0006] - receive identification information from the lead aircraft.

[0007] The system is remarkable in that the electronic circuitry is configured to:

[0008] - receive power level information from a received radio frequency signal of the lead aircraft by the follow aircraft, the radio frequency signal received by the follow aircraft corresponding to a radio frequency signal intended to be emitted by the lead aircraft with a substantially constant power throughout a phase of the formation flight; and

[0009] - to store a value of said power level, called the initial power value, in response to receiving the activation information for the formation flight guidance mode of the following aircraft and the identification information of the lead aircraft,

[0010] and in that the electronic circuitry is further configured to repeatedly implement the following steps during the participation of the follow aircraft in the formation flight:

[0011] - receive power level information from the radio frequency signal received from the lead aircraft by the follow aircraft;

[0012] - to store a value of said power level, called the current power value, at a current moment;

[0013] - calculate a difference between the current power value and the initial value of power ;

[0014] - determine a first risk of collision between the following aircraft and the leading aircraft if the calculated difference is greater than a power threshold; and

[0015] - in the event of determination of the first collision risk, order the emission from an alert in the cockpit of the following aircraft and command a disengagement of the following aircraft from the formation flight.

[0016] Thus, the collision avoidance monitoring system detects an increase in the power level of the radio frequency signal received from the lead aircraft. This increase in power level corresponds to a decrease in the distance between the following aircraft and the lead aircraft. When this distance decreases sufficiently for the power level increase to reach the power threshold, the monitoring system determines a risk of collision between the following aircraft and the lead aircraft and issues an alert in the cockpit. The collision avoidance monitoring system is therefore redundant with the TCAS system since it issues an alert when the following aircraft approaches too closely to the lead aircraft.

[0017] According to various embodiments which may be taken individually or in combination:

[0018] - the radio frequency signal received by the following aircraft corresponds to a signal radio frequency emitted by a DME or ADS-B type system of the lead aircraft;

[0019] - the power level information of the radio frequency signal received from the aircraft leader corresponds to a peak power level;

[0020] - said power threshold is chosen in a range [6dB ; 18dB], preferably 12dB;

[0021] - the electronic circuitry is further configured to receive information from The system uses the position of the following aircraft, obtained from a receiver of the following aircraft's satellite positioning system, and the position of the lead aircraft, obtained from a receiver of the lead aircraft's satellite positioning system. This information is used to determine the distance between the following and lead aircraft based on their respective position data, and to determine a second collision risk between the following and lead aircraft when this distance is less than a specified threshold. In one embodiment, the electronic circuitry is configured to trigger an alert in the cockpit of the following aircraft and to disengage the following aircraft from the formation flight if either the first or second collision risk is determined.According to another embodiment, the electronic circuitry is configured to trigger the issuance of an alert in the cockpit of the following aircraft and to trigger a disengagement of the following aircraft from the formation flight in the event of the determination of the first collision risk and the second collision risk.

[0022] The invention also relates to a method for anti-collision monitoring of a follower aircraft participating in a formation flight in which the follower aircraft flies close to a vortex generated by a lead aircraft, the method comprising the following steps implemented by electronic circuitry integrated into at least one avionics computer of the aircraft:

[0023] - receive activation information for a guidance mode, such as flight in formation of the follow aircraft; and

[0024] - receive lead aircraft identification information.

[0025] The process is remarkable in that it comprises the following steps:

[0026] - receive power level information from a received radio frequency signal of the lead aircraft by the follow aircraft, the radio frequency signal received by the follow aircraft corresponding to a radio frequency signal intended to be emitted by the lead aircraft with a substantially constant power throughout a phase of the formation flight; and

[0027] - to store a value of said power level, called the initial power value, in response to receiving the activation information for the formation flight guidance mode of the following aircraft and the identification information of the lead aircraft,

[0028] and in that it further comprises the following steps implemented repeatedly during the participation of the follow aircraft in the formation flight:

[0029] - receive power level information from the radio frequency signal received from the lead aircraft by the follow aircraft;

[0030] - to store a value of said power level, called the current power value, at a current moment;

[0031] - calculate a difference between the current power value and the initial value of power ;

[0032] - determine a first risk of collision between the following aircraft and the leading aircraft if the calculated difference is greater than a power threshold; and

[0033] - in the event of determination of the first collision risk, order the emission from an alert in the cockpit of the following aircraft and command a disengagement of the following aircraft from the formation flight.

[0034] In one embodiment, the method further comprises steps of receiving position information from the follower aircraft from a receiver of a satellite positioning system of the follower aircraft, as well as position information from the leader aircraft from a receiver of a satellite positioning system of the leader aircraft, of determining a distance between the follower aircraft and the leader aircraft on the basis of the position information of the follower aircraft and the leader aircraft and of determining a second risk of collision between the follower aircraft and the leader aircraft when this distance is less than a distance threshold.

[0035] The invention also relates to an aircraft comprising such an anti-collision monitoring system. Description of the implementation methods

[0036] The invention will be better understood upon reading the following description and examining the accompanying figures.

[0037] Fig. 1 is a view of an aircraft comprising an anti-collision monitoring system according to an embodiment of the invention.

[0038] Fig. 2 schematically illustrates an anti-collision monitoring system for a follow aircraft, according to one embodiment of the invention.

[0039] Fig. 3A illustrates a first situation of a follower aircraft in relation to a lead aircraft.

[0040] Fig. 3B illustrates a second situation of a follower aircraft in relation to a lead aircraft.

[0041] Fig. 3C illustrates a third situation of a follower aircraft in relation to a lead aircraft.

[0042] Figure 4 represents a method for anti-collision monitoring of a following aircraft, conforming to an embodiment of the invention.

[0043] The collision avoidance monitoring system 10 shown in [Fig. 2] is installed on board an aircraft such as aircraft 1 shown in [Fig. 1]. This collision avoidance monitoring system comprises electronic circuitry 14 integrated into at least one avionics computer of the aircraft, for example, an avionics computer installed in an avionics bay 2 of aircraft 1. The electronic circuitry 14 is connected as input to a radio frequency receiver 12 of the aircraft. More specifically, the radio frequency receiver 12 is configured to determine and transmit power level information from a radio frequency signal 22 received from a radio frequency transmitter 20 of a lead aircraft when aircraft 1 is participating in a formation flight as the follow aircraft of the lead aircraft.The radio frequency signal 22 considered corresponds to a radio frequency signal intended to be emitted by the lead aircraft with substantially constant power throughout a phase of the formation flight. Such a radio frequency signal corresponds, for example, to a radio frequency signal from a DME (Distance Measuring Equipment) or ADS-B (Automatic Dependent Surveillance-Broadcast) type system. The electronic circuitry 14 is also connected as an input to an information source 13 configured to determine and transmit identification information for a lead aircraft when aircraft 1 participates, as a follower aircraft, in a formation flight. The electronic circuitry 14 is also connected as an input to an information source 15 configured to determine and transmit activation information for a formation flight guidance mode for aircraft 1 as a follower aircraft.The electronic circuitry 14 is connected at the output to a display system 18 in the cockpit of aircraft 1, as well as to a guidance system 16 of aircraft 1.

[0044] During the initialization of a formation flight, the various aircraft participating in this formation flight position themselves relative to one another, according to a geometry such that a follow aircraft flies close to a vortex generated by a lead aircraft. The distances between the aircraft are chosen to ensure the flight safety of the various aircraft participating in the formation flight. In the remainder of this description, aircraft 1 is considered to be participating in the formation flight as a follow aircraft of a lead aircraft. When the various aircraft participating in the formation flight are correctly positioned according to this geometry, a formation flight guidance mode is activated for at least some of the aircraft participating in the formation flight as follow aircraft, including at least aircraft 1.According to a first alternative, the activation of the formation flight guidance mode is carried out automatically by a management system. of the formation flight system comprising at least one avionics computer on board aircraft 1. In particular, the information source 15 configured to determine and transmit the activation information for a formation flight guidance mode corresponds to this avionics computer. According to a second alternative, the activation of the formation flight guidance mode is performed manually by an aircraft pilot using a human-machine interface in the aircraft cockpit. In particular, the information source 15 configured to determine and transmit the activation information for a formation flight guidance mode corresponds to this human-machine interface or to a computer connected to this human-machine interface. The reception by the processing unit 14 of the activation information for a formation flight guidance mode corresponds to a step 31, labeled a1a, of the process illustrated in [Fig. 4].

[0045] At the latest at the time of initialization of the formation flight, the identity of the lead aircraft that aircraft 1 will follow as the follow aircraft is known on board aircraft 1. According to a first alternative, the formation flight is managed automatically by a formation flight management system comprising at least one avionics computer on board aircraft 1, and the information source 13 configured to determine and transmit the identification information of the lead aircraft then corresponds to this avionics computer. According to a second alternative, the identity of the lead aircraft is known to a pilot of aircraft 1 and is entered manually by this pilot using a human-machine interface in the aircraft's cockpit.In particular, the information source 13 configured to determine and transmit the lead aircraft identification information then corresponds to this human-machine interface or to a computer connected to this human-machine interface. The reception by the processing unit 14 of the lead aircraft identification information corresponds to a step 32, labeled a2, of the process illustrated in [Fig. 4].

[0046] Repeatedly during formation flight, or even during formation flight initiation, in a step 30 of the process, labeled A in [Fig. 4], the radio frequency receiver 12 receives radio frequency signals 22 from the radio frequency transmitter 20 of the lead aircraft. The radio frequency receiver 22 determines a power level information for the radio frequency signals 22, in particular a peak power level information, and transmits this information to the electronic circuitry 14. Following formation flight initiation, in response to receiving the lead aircraft identification information from the information source 13, as well as the formation flight guidance mode activation information from the information source 15, the processing unit 14 stores a value of the power level received from the radio frequency receiver 12. In the rest of the description, this stored value of power level is called the initial power value.

[0047] According to a first alternative, immediately after receiving the identification information of the lead aircraft, from the information source 13, as well as the activation information of the formation flight type guidance mode, from the information source 15, the processing unit 14 stores a current value of the power level received from the radio frequency receiver 12. In the following description, this stored value of power level is referred to as the initial power value.

[0048] According to a second alternative, in particular if the processing unit 14 had not yet received power level information from the radio frequency receiver 12 when receiving the lead aircraft identification information and the formation flight guidance mode activation information, the processing unit stores as the initial power value the first power level information it receives from the radio frequency receiver 12 after receiving the lead aircraft identification information and the formation flight guidance mode activation information.

[0049] According to a third alternative, the processing unit stores, as an initial power value, an average of the first power level information it receives from the radio frequency receiver 12 during a time interval after (or before) receiving the lead aircraft identification information and the formation flight guidance mode activation information. In particular, the duration of the time interval is chosen to be at most 2 minutes, preferably at most 30 seconds. The storage of the initial power value by the processing unit 14 corresponds to step 30a, labeled a3, of the method illustrated in [Fig. 4].

[0050] During the participation of aircraft 1 in the formation flight, the processing unit 14 repeatedly implements the following steps as illustrated in [Fig.4]:

[0051] - a step 33, labeled B in [Fig.4], for memorizing a value of the level of power received from the radio frequency receiver 12, called current power value. In particular, this power level value corresponds, at a current instant, to the last value of the power level received from the radio frequency receiver 12, or to an average of the last values ​​of the power level received from the radio frequency receiver 12 during a time interval whose duration is, for example, at most equal to 1 minute, preferably at most equal to 30 seconds;

[0052] - a step 34, labeled C in the figure, of calculating a difference between the value current power and initial power value;

[0053] - a step 35, labeled D in the figure, for determining a first risk of collision between aircraft 1 and the lead aircraft if the difference calculated in step 34 is greater than a power threshold.

[0054] When positive, the difference calculated in step 34 corresponds to an increase in the power level of the radio frequency signal 22 received by the radio frequency receiver 12, between the time the initial power value was memorized and the current time. Since the radio frequency signal 22 is emitted by the lead aircraft with substantially constant power, an increase in the power level received by the radio frequency receiver 12 between these two times corresponds to a decrease in the distance between the lead aircraft and the follow aircraft 1. This is illustrated in Figures 3A, 3B, and 3C. In [Fig. 3A], a follow aircraft 1S is flying near a vortex V emitted by a lead aircraft IL. These two aircraft are separated by a distance L. This situation corresponds, for example, to a nominal aircraft positioning, such as at the start of formation flight.The power level of the radio frequency signal 22 then corresponds to the initial power value. In the situation illustrated in [Fig. 3B], aircraft 1S and IL have moved closer together, and the distance between them is now only half (L / 2) of the distance L. It follows from the laws of physics that the level of the radio frequency signal received by the radio frequency receiver 12 of the following aircraft 1S is inversely proportional to the square of the distance between the two aircraft. Therefore, the current power value is then +6dB (decibels) higher than the initial power value. In the situation illustrated in [Fig. 3C], aircraft 1S and IL have moved even closer together, and the distance between them is now only a quarter (L / 4) of the distance L. Therefore, the current power value is then +12dB (decibels) higher than the initial power value.

[0055] Consequently, the power threshold considered in step 35 corresponds to a decrease in the distance separating the follow aircraft 1S from the lead aircraft IL between the initiation of the formation flight and a current time. This threshold is chosen such that the corresponding distance between the follow aircraft and the lead aircraft ensures the safe flight of the aircraft without risk of collision. In one embodiment, it is chosen within a range of +6dB to +18dB, preferably equal to +12dB, which corresponds to the situation illustrated in [Fig. 3C].

[0056] In the absence of a risk of collision, the procedure is repeated from step 30. If a risk of collision is determined in step 35, during step 36, labeled E in [Fig. 4], the processing unit sends a signal to the display system 18 to trigger an alert in the cockpit of the following aircraft 1. This alert can be either visual or audible. In addition, the processing unit 14 sends a signal to the guidance system 16 to trigger a disengagement of the When the follow aircraft participates in the formation flight, the formation flight guidance mode is deactivated. The first follow aircraft is then piloted, either manually or automatically, to move away from the other aircraft participating in the formation flight, in order to avoid any risk of collision.

[0057] In a particular embodiment, the electronic circuitry 14 is further configured to receive position information from the following aircraft from a receiver of a satellite positioning system of the following aircraft, in particular from an MMR (Multi-Mode Receiver), as well as position information from the lead aircraft from a receiver of a satellite positioning system of the lead aircraft, to determine a distance between the following aircraft and the lead aircraft based on the position information of the following and lead aircraft and to determine a second risk of collision between the following and lead aircraft when this distance is less than a distance threshold. The position information of the lead aircraft is, for example, transmitted from the lead aircraft to the following aircraft by means of an ADS-B type system.The determination of the second risk is therefore redundant with the determination of the first risk in step 35.

[0058] According to a first embodiment, the processing unit 14 combines the first risk and the second risk using a logical AND operation to trigger the issuance of an alert in the cockpit of the follow aircraft and to disengage the follow aircraft from the formation flight. The redundancy in this first embodiment ensures that the issuance of the alert and the disengagement of the follow aircraft from the formation flight are only triggered if the determination of the first risk is confirmed by the determination of the second risk.

[0059] According to a second embodiment, the processing unit 14 combines the first risk and the second risk according to a logical OR to trigger the issuance of an alert in the cockpit of the follow aircraft and to disengage the follow aircraft from the formation flight. The redundancy according to this second embodiment ensures that the issuance of the alert and the disengagement of the follow aircraft from the formation flight are triggered even if there is a failure in determining which of the first and second risks is the most likely.

Claims

1. Demands 1) Collision avoidance monitoring system (10) of a follow aircraft (1, 1S) participating in a formation flight in which the follow aircraft flies in the vicinity of a vortex (V) generated by a lead aircraft (IL), the monitoring system comprising electronic circuitry (14) integrated into at least one avionics computer of the aircraft, in which the electronic circuitry is configured to implement the following steps: - receive (31) an activation notification for a guidance mode, such as formation flight, of the following aircraft; and - receive (32) lead aircraft identification information, characterized in that the electronic circuitry is configured to: - receive (30) power level information from a radio frequency signal (22) received from the lead aircraft by the follow aircraft, the radio frequency signal received by the follow aircraft corresponding to a radio frequency signal intended to be emitted by the lead aircraft with substantially constant power throughout a phase of formation flight; and - to memorize (30a) a value of said power level, called initial power value, in response to receiving the activation information of the formation flight guidance mode of the following aircraft and the identification information of the lead aircraft, and in that the electronic circuitry is further configured to repeatedly implement the following steps during the participation of the follow aircraft in the formation flight: - receive (30) a power level information of the radio frequency signal (22) received from the lead aircraft by the follow aircraft; - to memorize (33) a value of said power level, called current power value, at a current instant; - calculate (34) a difference between the current power value and the initial power value; - determine (35) a first risk of collision between the following aircraft and the leading aircraft if the calculated difference is greater than a power threshold; and - if the first risk of collision is determined, order (36) the issuance of an alert in the cockpit of the following aircraft and order a disengagement of the follow aircraft's participation in the formation flight.

2. 2) System according to claim 1, characterized in that said radio frequency signal (22) received by the follow aircraft corresponds to a radio frequency signal emitted by a DME type or ADS-B type system of the lead aircraft.

3. 3) System according to any one of claims 1 or 2, characterized in that the power level information of the radio frequency signal received from the lead aircraft corresponds to a peak power level.

4. 4) System according to any one of the preceding claims, characterized in that said power threshold is chosen in an interval [6dB; 18dB, preferably 12dB.

5. 5) System according to any one of the preceding claims, characterized in that the electronic circuitry (14) is further configured to receive position information from the follower aircraft (1, 1S) from a receiver of a satellite positioning system of the follower aircraft, and position information from the leader aircraft (IL) from a receiver of a satellite positioning system of the leader aircraft, to determine a distance between the follower aircraft and the leader aircraft on the basis of the position information of the follower aircraft and the leader aircraft and to determine a second risk of collision between the follower aircraft and the leader aircraft when this distance is less than a distance threshold.

6. 6) System according to claim 5, characterized in that the electronic circuitry is configured to control the issuance of an alert in the cockpit of the follow aircraft and to control a disengagement of the follow aircraft's participation in the formation flight in the event of determination of the first risk of collision or the second risk of collision.

7. 7) System according to claim 5, characterized in that the electronic circuitry is configured to control the issuance of an alert in the cockpit of the follow aircraft and to control a disengagement of the follow aircraft's participation in the formation flight in the event of determination of the first collision risk and the second collision risk.

8. 8) A method for collision avoidance monitoring of a follower aircraft (1, 1S) participating in a formation flight in which the follower aircraft flies in the vicinity of a vortex (V) generated by a lead aircraft (IL), the method comprising the following steps implemented by an electronic circuitry (14) integrated into at least one avionics computer of the aircraft: - receiving (31) an activation information for a guidance mode, of the formation flight type, of the follow aircraft; and - receiving (32) an identification information for the lead aircraft, characterized in that the method comprises: - receiving (30) a power level information of a radio frequency signal received from the lead aircraft by the follow aircraft, the radio frequency signal received by the follow aircraft corresponding to a radio frequency signal intended to be emitted by the lead aircraft with a substantially constant power throughout a phase of the formation flight;and - store (30a) a value of said power level, referred to as the initial power value, in response to the reception of the activation information of the formation flight guidance mode of the follow aircraft and the identification information of the lead aircraft, and in that it further comprises the following steps carried out repeatedly during the participation of the follow aircraft in the formation flight: - receive (30) power level information of the radio frequency signal received from the lead aircraft by the follow aircraft; - store (33) a value of said power level, referred to as the current power value, at a current time; - calculate (34) a difference between the current power value and the initial power value; - determine (35) a first risk of collision between the follow aircraft and the lead aircraft if the calculated difference is greater than a power threshold;and - in the event of determination of the first risk of collision, order (36) the issuance of an alert in the cockpit of the following aircraft and order a disengagement of the following aircraft from the formation flight.;

9. 9) A method according to claim 8, characterized in that it further comprises steps for receiving position information from the following aircraft from a receiver of a positioning system

10. by satellites of the following aircraft, as well as position information of the lead aircraft from a receiver of a satellite positioning system of the lead aircraft, determination of a distance between the following aircraft and the lead aircraft on the basis of the position information of the following aircraft and the lead aircraft and determination of a second risk of collision between the following aircraft and the lead aircraft when this distance is less than a distance threshold. 10) Aircraft (1), characterized in that it comprises a surveillance system (10) according to any one of claims 1 to 7.

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