Method and device for verifying a guidance signal

Patent metadata

Field	Value
Publication number	US-10794727-B2
Application number	US-201715614683-A
Country	US
Kind code	B2
Filing date	Jun 6, 2017
Priority date	Jun 9, 2016
Publication date	Oct 6, 2020
Grant date	Oct 6, 2020

Abstract

A verification method comprising a first step of measuring at least one position parameter of an aircraft and a first set of steps implemented after the flight of at least one aircraft, in an automatic and repetitive manner, comprising computing a geographical height of an aircraft with respect to the runway on the basis of the position parameters of an aircraft, computing an evaluated vertical deviation, between the geographical height and a reference height, and computing a vertical error on the basis of a comparison between the evaluated vertical deviation and the reference vertical deviation.

First claim

The invention claimed is:

1. A method for determining an error in at least one guidance signal representative of a reference deviation between a position of an aircraft and a reference approach trajectory including a vertical guidance signal representative of a reference vertical deviation from the reference approach trajectory, the signals being transmittable to the aircraft each by a ground emitter device to assist the aircraft with landing on a runway, comprising:
measuring and recording in a memory, in a first measurement step, implemented by at least one first measurement module onboard at least one aircraft, in an automatic and repetitive manner, during at least one flight of the aircraft along an approach trajectory of the aircraft, during an approach to the runway, the measuring and recording being of at least one position parameter of the aircraft and a parameter corresponding to the vertical guidance signal;
implementing a first set of steps, after the flight of the at least one aircraft, in an automatic and repetitive manner, the first set of steps comprising, for each of a plurality of different distances with respect to a threshold of the runway along the approach trajectory of the aircraft:
a height computation step, implemented by a first computation module, comprising computing a geographical height of an aircraft with respect to the runway on the basis of the position parameters of an aircraft,
a vertical deviation computation step, implemented by a second computation module, comprising computing a vertical deviation, termed the evaluated vertical deviation, between the geographical height and a reference height,
a vertical error computation step, implemented by a third computation module, comprising computing a vertical error on the basis of a comparison between the evaluated vertical deviation and the reference vertical deviation determined as a function of the parameter corresponding to the vertical guidance signal.

2. The method as claimed in claim 1 , wherein the evaluated vertical deviation is computed with the aid of the following equation: ΔZ dev =H geo −X tan θ, in which:
X is the distance with respect to the threshold of the runway along an approach trajectory of the aircraft,
θ is the slope between the reference approach trajectory and a plane comprising the runway, and
H geo is the geographical height of the aircraft.

3. The method as claimed in claim 1 , wherein
the first measurement step comprises:
measuring a height relative to the ground with the aid of a radio altimeter embedded onboard forming part of the first measurement module,
measuring an attitude of the aircraft with the aid of a geolocation module embedded onboard forming part of the first measurement module,
storing the height, the altitude and the reference vertical deviation in a memory;

the height computation step comprising:
a sub-step of computing the geographical height comprising, for each of a plurality of different distances with respect to the threshold of the runway along the approach trajectory of the aircraft, in computing, as the geographical height of the aircraft, the sum of the reference vertical deviation and the product of a current one of the plurality of different distances with respect to the threshold of the runway and of a tangent of a slope of the reference approach trajectory;
a sub-step of computing a reference terrain profile, implemented by a second computation sub-module, comprising computing, on the basis of the geographical height, a reference terrain profile along an approach axis of an aircraft, the terrain profile representing an evolution of a height of the terrain before the threshold of the runway as a function of the distance with respect to the threshold of the runway,
a sub-step of computing an offset of the reference terrain profile, implemented by a third computation sub-module, comprising computing an offset between the reference terrain profile and a terrain profile determined on the basis of heights measured by the radio altimeter,
a sub-step of computing a straightened terrain profile, implemented by a fourth computation sub-module, comprising setting the reference terrain profile on the terrain profile determined on the basis of heights measured by the radio altimeter by subtracting the computed offset from each distance with respect to the threshold of the runway.

4. The method as claimed in claim 3 , wherein the geographical height is computed with the aid of the following equation:
H geo ( X )= H RA ( X−ΔX )+PrOf( X ), in which:
X is the distance with respect to the threshold of the runway,
ΔX is the offset between the reference terrain profile and the terrain profile determined on the basis of heights measured by the radio altimeter,
H RA (X) is the height measured by the radio altimeter at a distance X with respect to the threshold of the runway,
Prof(X) is the terrain profile determined on the basis of heights measured by the radio altimeter as a function of the distance X with respect to the threshold of the runway.

5. The method as claimed in claim 1 , wherein:
the first measurement step furthermore comprises:
measuring an attitude of the aircraft with the aid of a geolocation module embedded onboard forming part of the first measurement module,
storing the altitude and the reference vertical deviation in a memory;

the height computation step comprises:
a sub-step of computing geographical height comprising, for each of a plurality of different distances with respect to the threshold of the runway along the approach axis of the aircraft:
computing an error constant due to the geolocation module in the altitude measurement, the error constant being at least one of computed by when the aircraft touches the ground or measured by the radio altimeter when the aircraft passes above the threshold of the runway,
computing a geographical height measured by the geolocation module corresponding to the difference between the altitude measured by the geolocation module and an altitude of the threshold of the runway, stored in a memory,
computing the geographical height corresponding to the difference between the geographical height measured by the geolocation module and the error constant engendered by the geolocation module.

6. The method as claimed in claim 5 , wherein the geographical height is computed with the aid of the following equation: H geo (X)=H GPS (X)+ΔH in which:
X is the distance with respect to the threshold of the runway,
H GPS (X) is the height measured by the geolocation module,
ΔH is the error constant engendered by the geolocation module.

7. The method as claimed in claim 1 , wherein
the first measurement step further comprises:
measuring a barometric height of the aircraft, with the aid of a barometric altimeter embedded onboard forming part of the first measurement module,
measuring a total air temperature and a Mach number of the aircraft, with the aid of sensors embedded onboard forming part of the first measurement module,
storing the barometric height, the temperature, the Mach number and the reference vertical deviation in a memory,

the height computation step comprises:
a sub-step comprising, for each of a plurality of different distances with respect to the threshold of the runway along the approach trajectory of the aircraft:
estimating, with the aid of the total air temperature, the Mach number and of the barometric height, a variation of the static temperature dependent on the altitude and a ground temperature,
computing the geographical height with the aid of the barometric height, of the variation of the static temperature and of the ground temperature.

8. The method as claimed in claim 7 , wherein the geographical h

Assignees

• Airbus Operations Sas

Inventors

• Bourret Thierry
• Marconnet Nicolas

Classifications

• G01S19/48 Primary

  by combining or switching between position solutions derived from the satellite radio beacon positioning system and position solutions derived from a further system · CPC title

• G08G5/74

  for monitoring terrain · CPC title

• G08G5/54

  for approach or landing · CPC title

• G08G5/21

  located onboard the aircraft · CPC title

• G05D1/0676

  specially adapted for landing · CPC title