Method for controlling transmission power and aircraft anti-collision system for implementing such a method

• US 10,132,923 B2
• Filed: 06/09/2016
• Issued: 11/20/2018
• Est. Priority Date: 06/10/2015
• Status: Expired due to Fees

• Current Assignee: Airbus Operations SAS (Airbus SE)
• Original Assignee: Airbus Operations SAS (Airbus SE)
• Inventors: Robin, Jean-Luc
• Primary Examiner(s): Windrich, Marcus E
• Application Number:
  US15/735,512
• Publication Number:
  US 20180156912A1
• Time in Patent Office: 894 Days
• Field of Search: 342 29, 342 30, 342 42
• CPC Class Codes: G01S 13/765 with exchange of information between interrogator and responder
• CPC Class Codes: G01S 13/933 of aircraft or spacecraft
• CPC Class Codes: G01S 7/282 Transmitters
• CPC Class Codes: G01S 7/4013 involving adjustment of the transmitted power

Abstract

A method and system for controlling the transmission of power of request-response messages implemented by a system to prevent collisions between a first aircraft and a second aircraft. The method comprises measuring at least the value, referred to as the quality value, of a quantity representative of the reception quality of the transponder of the second aircraft and, implemented by the anti-collision device of the first aircraft, and a control step to control the transmission power of the radio-frequency signals carrying the request-response messages according to the quality value or values contained in the response messages sent by the transponder.

Claims

1. A method for controlling a transmission power of response request messages carried out by a TCAS system for preventing a collision of a first aircraft and a second aircraft, said system being of a type comprising an anti-collision apparatus with which said first aircraft is provided and a transponder with which said second aircraft is provided, said method comprising the following steps which are carried out by the anti-collision apparatus:

transmitting request messages in a form of radiofrequency signals which carry said messages, and

receiving radiofrequency signals which carry response messages which are transmitted by said transponder in response to the request messages,

said method further comprising the following steps which are carried out by said transponder;

receiving radiofrequency signals which carry request messages which are transmitted by said anti-collision apparatus, and

transmitting radiofrequency signals which carry response messages in response to request messages,

measuring at least one value, referred to as a quality value, of a variable which represents the quality of reception by a reception channel of the radiofrequency signals which carry request messages transmitted by the anti-collision apparatus, and

encapsulating data which represent said at least one quality value in said response message and,

a further step, carried out by said anti-collision apparatus;

controlling a transmission power of the radiofrequency signals which carry said request messages in accordance with the at least one quality value which is encapsulated in the response messages which are transmitted by said transponder,

wherein the control step comprises;

comparing the quality value with a threshold value,

increasing the transmission power of a next request message to be transmitted when a quality represented by the quality value is less than the quality represented by the threshold value, and

decreasing the transmission power of the next request message to be transmitted when the quality represented by the quality value is greater than the quality of the threshold value,

further comprising establishing aeronautical data and modifying the threshold value in accordance with values of said aeronautical data.

2. The method for controlling power as claimed in claim 1, wherein the quality value of the radiofrequency signal measured in the measuring step is the value of at least one of the following characteristics:

a reception power of the radiofrequency signals which carry a request message Req received by the transponder,

a signal-to-noise ratio of the radiofrequency signal which carries a request message Req received by the transponder, or

a bit error rate of the radiofrequency signal which carries a request message Req received by the transponder.

3. A method for controlling a transmission power of response request messages carried out by an anti-collision apparatus of a TCAS system to prevent a collision of a first aircraft and a second aircraft, said system being of a type comprising the anti-collision apparatus with which said first aircraft is provided and a transponder with which said second aircraft is provided, said method comprising the following steps:

transmitting request messages in a form of radiofrequency signals which carry said request messages, and

receiving radiofrequency signals which carry response messages which are transmitted by said transponder in response to said request messages, and

controlling a transmission power of the radiofrequency signals which carry said request messages in accordance with one or more quality values encapsulated in the response messages transmitted by said transponder,

wherein the control step comprises;

comparing the quality value with a threshold value,

increasing the transmission power of a next request message to be transmitted when a quality represented by the quality value is less than the quality represented by the threshold value, and

decreasing the transmission power of the next request message to be transmitted when the quality represented by the quality value is greater than the quality of the threshold value,

further comprising establishing aeronautical data and modifying the threshold value in accordance with values of said aeronautical data.

4. The method for controlling power as claimed in claim 3, further comprising a step of re-initializing the transmission power at a value greater than a current value if the receiving step does not receive any response to a request message previously transmitted by the anti-collision apparatus.

5. The method for controlling power as claimed in claim 4, wherein said re-initializing step re-initializes the transmission power at the maximum power.

6. The method for controlling power as claimed in claim 3, further comprising a step of adjusting the threshold value.

7. The method for controlling power as claimed in claim 6, wherein said adjusting step comprises establishing a frequency of absences of any response to the request messages and correcting the threshold value in accordance with the established frequency.

8. The method for controlling power as claimed in claim 3, further comprising controlling the transmission power of a next request message to be transmitted as:

Pt=Pmax+20 Log(r/10),

Pt being the transmission power, Pmax being a predetermined maximum power and r being a distance which separates the aircraft provided with the anti-collision apparatus and the aircraft which is provided with the transponder, said control step being carried out when the response message received does not contain data relating to the quality value of the radiofrequency signals previously received by said transponder.

9. The method for controlling power as claimed in claim 3, wherein said aeronautical data are at least one of the following:

a time before collision,

a distance between the first aircraft and the second aircraft,

a relative speed defined as being a variation over time of the distance,

a precision of a bearing defined as being an angle between a direction of the second aircraft and a heading of the first aircraft, and

a relative altitude of the first and second aircraft or the derivative thereof in relation to time.

10. The method for controlling power as claimed in claim 9, wherein the threshold value can be decreased when:

the distance between the first and second aircraft decreases,

the time before collision decreases over time,

the relative speed between the first and second aircraft increases,

the bearing oscillates greatly on a navigation display,

at least one of the relative altitude decreases or its derivative increases.

11. A method for controlling power carried out by a transponder of a first aircraft, comprising:

receiving the radiofrequency signals which carry a request message transmitted by a TCAS anti-collision apparatus of a second aircraft,

processing a response message, the response message being usable by the TCAS anti-collision apparatus to determine a distance between the first aircraft and the second another aircraft, a relative speed between the first aircraft and the second aircraft, an estimated time before a possible collision, and an angle between a heading of the first aircraft and a direction of the second aircraft,

measuring a quality of the radiofrequency signals received in the receiving step,

encapsulating, in the response message processed in the processing step, data which represent a quality value Q which is measured, and

transmitting, in the form of radiofrequency signals, the response message which results from the processing and encapsulating steps.

12. A TCAS system for preventing the collision of a first aircraft and a second aircraft, of the type comprising an anti-collision apparatus which is fitted to said first aircraft and a transponder which is fitted to said second aircraft, said anti-collision apparatus comprising:

a transmission channel for transmitting request messages in the form of radiofrequency signals which carry said messages and

a receiver for receiving radiofrequency signals which carry response messages which are transmitted by said transponder in response to said request messages,

said transponder comprising;

a reception channel for receiving radiofrequency signals which carry request messages which are transmitted by an anti-collision apparatus and

a transmitter for transmitting radiofrequency signals which carry response messages in response to request messages,

wherein said transponder comprises a measuring unit for measuring at least one value, referred to as a quality value, of a variable which represents the quality of reception by the reception channel of the radiofrequency signals which carry request messages which are transmitted by the anti-collision apparatus and an encapsulation unit for encapsulating said at least one quality value in said response message, and

wherein said anti-collision apparatus comprises a control unit for controlling a transmission power of the transmission channel in accordance with the at least one quality value which is encapsulated in the response messages transmitted by said transponder,

wherein the control step comprises;

comparing the quality value with a threshold value,

increasing the transmission power of a next request message to be transmitted when a quality represented by the quality value is less than the quality represented by the threshold value, and

decreasing the transmission power of the next request message to be transmitted when the quality represented by the quality value is greater than the quality of the threshold value,

the control step further comprising establishing aeronautical data and modifying the threshold value in accordance with values of said aeronautical data.

13. The anti-collision apparatus of a system for preventing the collision of the first aircraft and the second aircraft as claimed in claim 12, said anti-collision apparatus comprising a transmission channel for transmitting request messages in the form of radiofrequency signals which carry said messages to the transponder of the second aircraft and the receiver for receiving radiofrequency signals which carry response messages which are transmitted by said transponder in response to said request messages, wherein said anti-collision apparatus comprises a control unit for controlling the transmission power of the transmission channel in accordance with the at least one quality values which is encapsulated in the response messages which are transmitted by said transponder.

14. The transponder of a system for preventing the collision of the first aircraft and the second aircraft as claimed in claim 12, said transponder comprising the reception channel for receiving radiofrequency signals which carry request messages which are transmitted by an anti-collision apparatus and a transmitter for transmitting radiofrequency signals which carry response messages in response to request messages, wherein the transponder comprises the measuring unit for measuring at least the at least one quality value of the variable which represents the quality of reception by the reception channel of the radiofrequency signals which carry request messages which are transmitted by the anti-collision apparatus and the encapsulation unit for encapsulating said at least one quality value in said response message.