METHOD OF MEASURING HEIGHT AND DETECTING OBSTACLES, A RADIOALTIMETER, AND AN AIRCRAFT

• US 20120229325A1
• Filed: 03/07/2012
• Published: 09/13/2012
• Est. Priority Date: 03/11/2011
• Status: Active Grant

• Current Assignee: Airbus Helicopters
• Original Assignee: Eurocopter
• Inventors: Dutruc, Herve
• Granted Patent: US 9,239,381 B2
• Time in Patent Office: Days
• US Class Current: 342/29
• CPC Class Codes: G01S 13/87 Combinations of radar systems, e.g. primary radar and secondary radar
• CPC Class Codes: G01S 13/882 for altimeters measuring height using barometric means G01C5/06
• CPC Class Codes: G01S 13/91 for traffic control G01S13/93 takes precedence
• CPC Class Codes: G01S 13/933 of aircraft or spacecraft
• CPC Class Codes: G01S 13/935 for terrain-avoidance
• CPC Class Codes: G01S 7/03 Details of HF subsystems specially adapted therefor, e.g. common to transmitter and receiver

Abstract

A radioaltimeter (5) having a signal generator-receiver (10) and signal transceiver means (20) connected to the generator-receiver (10), and a display member (30), said transceiver means (20) comprising a transceiver main member (21) for sending a signal towards a ground (S) in order to determine the height (H) between said main member (21) and said ground (S), said display member (30) having main display means (31) for displaying said height (H). Furthermore, the radioaltimeter (5) includes switch means (40) together with a control unit (50), and secondary display means (32) of said display member (30).

Claims

1. A radioaltimeter having a signal generator-receiver and signal transceiver means connected to the generator-receiver, and a display member, said transceiver means comprising a transceiver main member for sending a signal towards the overflow ground (S) in order to determine a height (H) between said main member and said ground (S), said display member having main display means for displaying said height (H), wherein the radioaltimeter includes switch means together with a control unit, and secondary display means of said display member, the transceiver means including at least one transceiver secondary member for detecting an obstacle other than the ground (S), said main member and each secondary member being connected to the switch means, said radioaltimeter including a member for evaluating detected obstacles to determine a level of danger for each detected obstacle, said display member including secondary display means for displaying information relating to the detected obstacle that presents the highest level of danger, said control unit being connected to the switch means to put said main member and each secondary member (22) in direct connection with said signal generator-receiver (10) in a cycle and for modifying said cycle if an obstacle is detected.

2. A radioaltimeter according to claim 1, wherein said control unit is connected to the generator-receiver to receive information relating to the propagation duration of a signal transmitted by a secondary member and reflected by an obstacle back to said secondary member, and said control unit is connected to the display means to display information relating to at least one detected obstacle on the secondary display means.

3. A radioaltimeter according to claim 1, including at least one position-determination member for determining the position of an aircraft, said member being selected from a list including:

means for detecting the forward speed of an aircraft;

mapping means;

means for detecting the altitude of an aircraft; and

means for detecting the attitude of an aircraft.

4. A radioaltimeter according to claim 1, including manual selector means connected to the control unit to enable an individual to select said cycle from a predetermined catalog.

5. A radioaltimeter according to claim 4, wherein said catalog includes at least one of the following cycles:

a first cycle including scanning the main member and at least one secondary member selected from a plurality of secondary members;

a second cycle including scanning the main member and each secondary member; and

a third cycle including scanning the main member and each secondary member, secondary members detecting obstacles being used during each cycle for a first number of times, and secondary members not detecting obstacles being used during each cycle for a second number of times, less than said first number of times.

6. A radioaltimeter according to claim 1, including alarm means for indicating the presence of an obstacle.

7. An aircraft, including a radioaltimeter according to claim 1 for measuring the height (H) of the aircraft and for detecting obstacles other than the ground overflown by the aircraft, in a spherical volume surrounding said aircraft.

8. An aircraft according to claim 7, wherein said aircraft extends longitudinally from a rear end to a front end, in elevation from a bottom portion to a top portion, and transversely from a left side to a right side, said aircraft being included in a spherical volume presenting a bottom main sector between the ground and the bottom portion of the aircraft, at least one front secondary sector facing the front end, at least one rear secondary sector facing the rear end, at least one left side secondary sector facing the left side, and at least one right side secondary sector facing the right side, said main member having the function of pointing towards said bottom main sector, and said radioaltimeter comprises at least:

a front secondary member for detecting an obstacle in the front secondary sector;

a rear secondary member for detecting an obstacle in the rear secondary sector;

a left side secondary member for detecting an obstacle in the left side secondary sector; and

a right side secondary member for detecting an obstacle in the right side secondary sector.

9. A method of making safe the flight of an aircraft by avoiding obstacles other than the ground overflown by the aircraft, said aircraft extends longitudinally from a rear end to a front end, in elevation from a bottom portion to a top portion, and transversely from a left side to a right side, a spherical volume surrounding said aircraft and including a main sector directed towards the ground and at least one secondary sector, the method comprising the following steps:

transmitting successively in a given modifiable cycle;

firstly a main signal in the main sector to measure the height (H) between the aircraft and the overflown ground (S); and

secondly secondary signals into each of said secondary sectors in order to detect the presence of obstacles in said secondary sectors;

if an obstacle is detected in a given secondary sector, then referred to as a risky sector, modifying said cycle to increase the first number of signals transmitted into said risky sector compared with the second number of signals transmitted into the other secondary sectors and the main sector;

establishing a level of danger for each obstacle detected in secondary sectors; and

displaying the height (H) of the aircraft on main display means, and displaying information relating to the detected obstacle having the highest level of danger.

10. A method according to claim 9, wherein said given cycle is established with the help of selector means operable by the pilot of the aircraft.

11. A method according to claim 9, wherein once an obstacle has been detected in a front secondary sector situated in front of the aircraft relative to the forward direction of said aircraft, the safety distance between the aircraft and the obstacle is established and then the time to a potential impact with said obstacle is established, the level of danger being established as a function of said time or of said distance.

12. A method according to claim 11, wherein when the forward speed of the aircraft is less than a predetermined threshold, the level of danger is established as a function of said safety distance;

and wherein when the forward speed of the aircraft is greater than or equal to the predetermined threshold, the level of danger is established as a function of said time.

13. A method according to claim 9, wherein once an obstacle has been detected in a side secondary sector of said spherical volume situated on the left side or on the right side of the aircraft relative to the forward direction of said aircraft, the distance between the aircraft and the obstacle is established, and the level of danger is established as a function of said distance.

14. A method according to claim 9, wherein for an aircraft having a rotary wing describing a circle of given radius (R), the measured distance between the obstacle and the transceiver means of the aircraft is established and the level of danger is established as a function of the security distance that is equal to the difference between said radius (R) and said measured distance.