GB1572474A - Creación de Inventos y Patentes con Inteligencia Artificial

GB1572474A – Method of guiding aerodynes when landing
– Google Patents

GB1572474A – Method of guiding aerodynes when landing
– Google Patents
Method of guiding aerodynes when landing

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Publication number
GB1572474A

GB1572474A
GB17137/77A
GB1713777A
GB1572474A
GB 1572474 A
GB1572474 A
GB 1572474A
GB 17137/77 A
GB17137/77 A
GB 17137/77A
GB 1713777 A
GB1713777 A
GB 1713777A
GB 1572474 A
GB1572474 A
GB 1572474A
Authority
GB
United Kingdom
Prior art keywords
camera
aerodyne
contrasting
respect
landing
Prior art date
1976-04-29
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)

Expired

Application number
GB17137/77A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)

Societe de Fabrication dInstruments de Mesure SFIM SA

Original Assignee
Societe de Fabrication dInstruments de Mesure SFIM SA
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
1976-04-29
Filing date
1977-04-25
Publication date
1980-07-30

1977-04-25
Application filed by Societe de Fabrication dInstruments de Mesure SFIM SA
filed
Critical
Societe de Fabrication dInstruments de Mesure SFIM SA

1980-07-30
Publication of GB1572474A
publication
Critical
patent/GB1572474A/en

Status
Expired
legal-status
Critical
Current

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Classifications

G—PHYSICS

G01—MEASURING; TESTING

G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES

G01S3/00—Direction-finders for determining the direction from which infrasonic, sonic, ultrasonic, or electromagnetic waves, or particle emission, not having a directional significance, are being received

G01S3/78—Direction-finders for determining the direction from which infrasonic, sonic, ultrasonic, or electromagnetic waves, or particle emission, not having a directional significance, are being received using electromagnetic waves other than radio waves

G01S3/782—Systems for determining direction or deviation from predetermined direction

G01S3/785—Systems for determining direction or deviation from predetermined direction using adjustment of orientation of directivity characteristics of a detector or detector system to give a desired condition of signal derived from that detector or detector system

G01S3/786—Systems for determining direction or deviation from predetermined direction using adjustment of orientation of directivity characteristics of a detector or detector system to give a desired condition of signal derived from that detector or detector system the desired condition being maintained automatically

G01S3/7864—T.V. type tracking systems

G—PHYSICS

G05—CONTROLLING; REGULATING

G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES

G05D1/00—Control of position, course or altitude of land, water, air, or space vehicles, e.g. automatic pilot

G05D1/04—Control of altitude or depth

G05D1/06—Rate of change of altitude or depth

G05D1/0607—Rate of change of altitude or depth specially adapted for aircraft

G05D1/0653—Rate of change of altitude or depth specially adapted for aircraft during a phase of take-off or landing

G05D1/0676—Rate of change of altitude or depth specially adapted for aircraft during a phase of take-off or landing specially adapted for landing

G—PHYSICS

G05—CONTROLLING; REGULATING

G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES

G05D1/00—Control of position, course or altitude of land, water, air, or space vehicles, e.g. automatic pilot

G05D1/08—Control of attitude, i.e. control of roll, pitch, or yaw

G05D1/0808—Control of attitude, i.e. control of roll, pitch, or yaw specially adapted for aircraft

G05D1/0858—Control of attitude, i.e. control of roll, pitch, or yaw specially adapted for aircraft specially adapted for vertical take-off of aircraft

Description

(54) METHOD OF GUIDING AERODYNES WHEN LANDING
(71) We, SOCIETE DE FABRICA
TION D’INSTRUMENTS DE MESURE (S.F.I.M) of 13, Avenue Marcel Ramolfo
Garnier 91301, Massy, France, a French
Societe Anonyme, do hereby declare the invention for which we pray that a Patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:
The present invention relates to a method of guiding aerodynes when landing.
Aerodynes are usually guided by means of ground-installed ratio-electric devices, some of which transmit position data to the
aerodyne in flight. With other devices, a
radio-electric beam is transmitted and the
aerodyne must be maintained in the centre of
this beam so as to arrive at the desired landing point.
These radio-electric transmitter devices are heavy, bulky and expensive and can only be used for landing grounds which are permanently installed and equipped, whilst one of the essential characteristics of certain
aerodynes such as helicopters is their ability to land anywhere.
Furthermore, the radio-electric transmis
sions are easily locatable, this rendering their
use detrimental in military applications.
Finally, the slope of landing of the
aerodyne towards the point of landing is
imposed by the ground equipment and the
pilot cannot control this.
The present invention intends to eliminate
these drawbacks by proposing a new method
of guiding in which the data necessary for
landing are established in the aerodyne itself
and not by means of a ground equipment, so
that the aerodyne is no longer dependent on
an installation on an equipped landing
ground, but may on the contrary land any
where, even with automatic pilot.
The method of guiding according to the
invention comprises the steps of:
– optically sighting an object placed on the landing ground by means of a television camera carried in the aerodyne, said object having a luminance in the visible or I.R. spectrum contrasting with the background,
– maintaining the contrasting object in the field of the camera.
– locating the direction of the contrasting object with respect to a reference axis of the aerodyne,
– determining the attitude of the aerodyne,
– deducing therefrom, by a change in coordinates, the elevation and bearing of the aerodyne with respect to the object,
– and piloting the aerodyne according to the elevation and bearing data thus determined.
The method according to the invention therefore requires on the ground only an object having a luminance contrasting in the visible or I.R. spectrum with respect to the luminous background which surrounds it.
The object may be active (for example a light source) or passive (for example a marker).
The object may be dropped from the aerodyne itself onto the place chosen for landing, in order to avoid the need to resort to any human activity on the landing place.
From the aerodyne elevation and bearing data, landing is preferably carried out by automatic flight, the data being transmitted to an automatic pilot which establishes a programmed landing sequence, along a chosen path, until the aerodyne lands.
The camera may be free to rotate and automatically servo-controlled so as to maintain, by automatic tracking, the object sighted on the optical axis of the camera, or the camera may be fixed and the direction of the contrasting object with respect to the aerodyne be located by measuring the deviation of the position of the image of the object on the optoelectric sensitive screen of the camera from two axes.
The apparatus used for carrying out this method may comprise a television camera and also a means for locating the attitude of the aerodyne with respect to a ground reference axis, as well as an electronic computer assembly receiving both the aerodyne attitude data and the contrasting object direction data to convert said latter into data for oreientation of the aerodyne with respect to said ground reference axis, these data then being an indication of the elevation and bearing of the aerodyne with respect to the sighted object.
The system of locating the attitude of the aerodyne is a gyro unit or platform which is normally provided in an aerodyne.
If desired, two (or more) contrasting objects may be used, placed at a known distance from one another in a known direction (for example vertical), the distance between the images of the said objects on the sensitive screen of the camera enabling the altitude of the aerodyne to be determined.
The invention will be more readily understood on reading the following description with reference to the accompanying drawings, in which:
Figure 1 schematically shows an aerodyne above its landing point;
Figure 2 is a general view of an apparatus carried in a helicopter, for performing the preferred method of the invention; and
Figure 3 is a geometric representation of the relative position of the camera and a double contrasting object enabling the altitude of the aerodyne to be determined.
Referring now to the drawings, Figure 1 shows an aerodyne, in the present case a helicopter 10, above a landing ground 12 on which it has dropped an object 14 which defines a reference for indicating the desired landing spot.
The object 14 has the characteristic of being optically visible with respect to the background which surrounds it: it must present a sufficient luminance contrast with respect to said background for a television camera which observes it in its field of sight to supply a video signal which is sufficiently contrasting for the presence of the object 14 to be electronically detectable in this video signal.
Of course, the object may be placed in position at the desired landing spot, instead of being dropped from the helicopter.
The method of guiding when landing, according to the invention, consists normally in training a television camera 16 located in the helicopter 10 on the object 14, and in causing this camera to follow this object, locating at each instant the elevation s and bearing g (not shown in Figure 1) of the helicopter with respect to the object.
If its field is sufficient, the television camera 16 may be fixed; the object 14 is located by its position in the field by a two-axis measurement of the deviation of the position of the image of the object on the sensitive screen of the camera. If necessary, the camera will be provided with optical means with variable fields such as a zoom lens or switchable Galilean lenses with programmed or controlled positioning.
If the camera 16 is free to turn, an electronic tracking assembly and a camera positioning unit are associated therewith (not shown in Figure 1) which are capable of automatically swivelling the camera 16 to maintain the object 14 on the optical axis of the camera by using as control signals the above two-axis deviation measurements.
The direction of the optical axis of the camera with respect to a reference axis of the aerodyne is thereby determined, and the pilot of the helicopter or the automatic pilot receives this direction data and deduces therefrom the navigation data to be used in order to land at the desired spot.
As above indicated, the direction of the optical axis of the camera is located in terms of angular measurements with respect to the reference axis of the helicopter. Use is made of the data on the attitude of the helicopter course, pitch, roll), furnished by a gyro unit (or platform) on board the helicopter, in order to convert the direction of the optical axis of the camera with respect to a ground reference co-ordinate system (i.e. vertical, true north). This direction is permanently an indication of the elevation and bearing of the helicopter with respect to the object 14 and the automatic or manual flight is made on the basis of these data.
All the equipment necessary for guiding the landing of the helicopter is therefore mounted on board, this making the method according to the invention all the more advantageous.
Figure 2 schematically shows the apparatus on board the aerodyne for carrying out the preferred method according to the invention. The apparatus comprises a television camera 20, rotatably mounted on a positioning unit which comprises a pivot support 22 of the universal joint type and two electric motors 24 and 26 for rotating the camera 20 about axes 28 and 30 respectively of the universal joint and therefore swivelling it in any desired direction.
This positioning unit receives control signals via connections 32 and 34 (to the electric motors 24 and 26) from an electronic tracking unit 36 which is connected to the output of the camera 20 (via a connection 38) and which carries out the following functions: it receives the video signal coming from the camera and analyses it to determine the distribution of luminance in the field sighted by the camera; it elaborates two co-ordinate voltages, supplied to motors 24 and 26 respectively, representing the position of the image of the sighted object 14 with respect to the optical axis of the camera, in order to rotate the camera in the direction tending to annul these co-ordinate voltages, i.e. in a direction tending to maintain the optical axis of the camera centred on the object.
French Patent No. 2, 113, 939 reaches how to construct such an electronic unit. It functions by analysis of the contrast of the image produced by the camera, inside an electronic window which isolates a part of the field of the camera in order to analyse it.
This electronic window may move in the whole field of sight, automatically due to the electronic unit 36 or manually due to a window position control member 40 connected to the electronic unit 36 and provided with a manipulating handle 42 for manual actuation thereof.
The manipulator 42 is actuated in two directions to bring the electronic window onto the image of the object 14, which is checked on a television display 44 which receives signals from the electronic unit 36 (connection 50) and visualises both the image 46 of the video signal produced by the camera (in particular the image of the object 14) and an image of the electronic window or a reticle 48 representing the centre of the electronic window. It is the displacement of the electronic window in the field of the camera, either by means of the manipulator 42 or by automatic tracking, which produces height and width co-ordinate voltages which serve to control the motors swivelling the camera to maintain the electronic window of sight always at the centre of the display and so the optical axis of the camera on the object.
The manipulator 42 comprises a supplementary control knob 52 which serves to trigger the automatic tracking after the operator has manually brought the electronic window onto the contrasting object (i.e. after he has brought the recticle 48 onto the image 46 of the object 14). From the moment when the knob 52 is placed in automatic tracking position, the electronic unit 36 analyses at each instant the contrast of the image scanned in the electronic window, to maintain the image of the contrasting object inside the window.
If the object tends to move away from the centre of the electronic window, the electronic unit 36 tends to return the window towards the object in order to maintain the initial balance of contrasts, and the diplacement of the window will produce deviation voltages which are supplied to the motors to move the camera until the electronic window is at the centre of the TV display, and the optical axis of the camera centred on the sighted object.
There is therefore in fact a double tracking in the preferred method; tracking of the image of the object by the electronic window to maintain the window centered on the object, and tracking to maintain the window (and hence the image of the object) centrered in the TV display, this latter tracking being eliminated if the field of the camera is sufficient. Only the two axis measurements on the sensitive screen of the camera determine the direction of the sighted object according to the position of the electronic window which is no longer maintained at the centre of the TV display.
As may be seen in the above-mentioned
Patent, the electronic window is divided into four surface portions in which the luminance signal of the camera is integrated, and the results of the integrations are compared two by two in order to produce voltages controlling lateral displacement and vertical displacement of the electronic window in a direction tending to maintain the balance of the luminances integrated in each portion of window. The position of the window in the
TV display is measured by two voltage signals, and a deviation of the window with respect to a reference position (for example the centre of the TV display) causes the delivery of deviation voltages furnished to the motors swivelling the camera to return the window to the reference position.
The direction of the optical axis of the camera 20 is located at each instant by angular position measuring members 54 and 56, which are in the present case synchrotransmitters respectively coupled to the shafts of the motors 24 and 26 to transmit via connections 58 and 60 analogue signals representing the angle of rotation of each motor with respect to a reference position.
These signals furnish a calculator 62 with an indication, in the form of two angular co-ordinates, of the swivelling of the camera 20 with respect to a reference axis of the helicopter.
The calculator 62 also receives at each instant data on the attitude of the helicopter (course, pitch and roll), furnished by a gyrounit or platform 64 on board the helicopter; the calculator uses the data from the synchro-transmitters and those of the gyro to supply on two output connections 66 and 68 signals representing the direction of the camera in a ground axis reference system (east, true north, vertical).
These signals may be directly used for manual or automatic flight, as they represent at each instant the elevation and bearing of the helicopter with respect to the object 14, referred to ground.
It is also advantageous to know the altitude of the helicopter above the marker 14. Figure 3 shows how this may be done using a double contrasting object, i.e. two contrasting objects 14′ and 14″ connected by an arm of known length L. The two objects are to this end mounted on a chassis 70 which is so pivoted and unbalanced that the straight line joining these two markers is automatically vertical.
The tracking system is then similar to that of Figure 2 but the electronic unit 36 is capable of producing two tracking windows instead of one, each being able to take on one of the objects and follow it at each instant.
The position of the centre point between the two windows then serves as reference to supply deviation voltages so as to return this centre point at each instant to the centre of the field of sight of the camera.
Figure 3 shows the geometrical values connecting the elevation s of the helicopter (calculated from the swivelling of the camera as has been described with reference to Figure 2), the known horizontal length L between the markers 14′ and 14″, the altitude h which is sought and the distance e between the two electronic windows in the focal plane of the camera: h ‘ Lcossfsins = ewherefis the focal distance of the camera. In practice, the ratio of the distance e will be expressed as a voltage representing the deviation of the two windows centred on the images of the two objects furnished by the camera.
An electronic calculator receiving this voltage as well as the value s (calculated by the assembly 62 of Figure 2) calculates the altitude h by the above formula.
The pilot of the helicopter therefore has all the necessary data on the position of the helicopter with respect to the object on the ground to indicate the point of landing.
WHAT WE CLAIM IS:
1. A method of guiding an aerodyne, comprising the steps of:
– optically sighting an object placed on the landing ground by means of a television camera carried in the aerodyne, said object having a luminance in the visible or I.R. spectrum contrasting with the background,
– maintaining the contrasting object in the field of the camera,
– locating the direction of the contrasting object with respect to a reference axis of the aerodyne,
– determining the attitude of the aerodyne,
– deducing therefrom, by a change in coordinates, the elevation and bearing of the aerodyne with respect to the object,
– and piloting the aerodyne according to the elevation and bearing data thus determined.
2. The method as claimed in Claim 1, wherein the direction of the contrasting object with respect to the reference axis of the aerodyne is located by a deviation measurement according to the position of the image of the contrasting object on the electronic sensitive screen of the camera, the direction of the optical axis of the camera being determined with respect to the reference axis of the aerodyne.
3. The method as claimed in claim 1, wherein the camera is free to rotate and the contrasting object is maintained on the optical axis of the camera by automatic tracking of the image of the said object.
4. The method as claimed in Claims 1 to 3, wherein the contrasting object is dropped from the aerodyne, prior to the sighting operation, onto the landing site.
5. A method of guiding an aerodyne, substantially as hereinbefore described with reference to the accompanying drawings.
**WARNING** end of DESC field may overlap start of CLMS **.

Claims (5)

**WARNING** start of CLMS field may overlap end of DESC **. is so pivoted and unbalanced that the straight line joining these two markers is automatically vertical. The tracking system is then similar to that of Figure 2 but the electronic unit 36 is capable of producing two tracking windows instead of one, each being able to take on one of the objects and follow it at each instant. The position of the centre point between the two windows then serves as reference to supply deviation voltages so as to return this centre point at each instant to the centre of the field of sight of the camera. Figure 3 shows the geometrical values connecting the elevation s of the helicopter (calculated from the swivelling of the camera as has been described with reference to Figure 2), the known horizontal length L between the markers 14’ and 14″, the altitude h which is sought and the distance e between the two electronic windows in the focal plane of the camera: h ‘ Lcossfsins = ewherefis the focal distance of the camera. In practice, the ratio of the distance e will be expressed as a voltage representing the deviation of the two windows centred on the images of the two objects furnished by the camera. An electronic calculator receiving this voltage as well as the value s (calculated by the assembly 62 of Figure 2) calculates the altitude h by the above formula. The pilot of the helicopter therefore has all the necessary data on the position of the helicopter with respect to the object on the ground to indicate the point of landing. WHAT WE CLAIM IS:

1. A method of guiding an aerodyne, comprising the steps of:
– optically sighting an object placed on the landing ground by means of a television camera carried in the aerodyne, said object having a luminance in the visible or I.R. spectrum contrasting with the background,
– maintaining the contrasting object in the field of the camera,
– locating the direction of the contrasting object with respect to a reference axis of the aerodyne,
– determining the attitude of the aerodyne,
– deducing therefrom, by a change in coordinates, the elevation and bearing of the aerodyne with respect to the object,
– and piloting the aerodyne according to the elevation and bearing data thus determined.

2. The method as claimed in Claim 1, wherein the direction of the contrasting object with respect to the reference axis of the aerodyne is located by a deviation measurement according to the position of the image of the contrasting object on the electronic sensitive screen of the camera, the direction of the optical axis of the camera being determined with respect to the reference axis of the aerodyne.

3. The method as claimed in claim 1, wherein the camera is free to rotate and the contrasting object is maintained on the optical axis of the camera by automatic tracking of the image of the said object.

4. The method as claimed in Claims 1 to 3, wherein the contrasting object is dropped from the aerodyne, prior to the sighting operation, onto the landing site.

5. A method of guiding an aerodyne, substantially as hereinbefore described with reference to the accompanying drawings.

GB17137/77A
1976-04-29
1977-04-25
Method of guiding aerodynes when landing

Expired

GB1572474A
(en)

Applications Claiming Priority (1)

Application Number
Priority Date
Filing Date
Title

FR7612735A

FR2353893A1
(en)

1976-04-29
1976-04-29

METHOD AND APPARATUS FOR GUIDING AERODYNE ON LANDING

Publications (1)

Publication Number
Publication Date

GB1572474A
true

GB1572474A
(en)

1980-07-30

Family
ID=9172455
Family Applications (1)

Application Number
Title
Priority Date
Filing Date

GB17137/77A
Expired

GB1572474A
(en)

1976-04-29
1977-04-25
Method of guiding aerodynes when landing

Country Status (3)

Country
Link

DE
(1)

DE2718698C2
(en)

FR
(1)

FR2353893A1
(en)

GB
(1)

GB1572474A
(en)

Cited By (1)

* Cited by examiner, † Cited by third party

Publication number
Priority date
Publication date
Assignee
Title

US9891632B1
(en)

2016-08-15
2018-02-13
The Boeing Company
Point-and-shoot automatic landing system and method

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* Cited by examiner, † Cited by third party

Publication number
Priority date
Publication date
Assignee
Title

DE3644478A1
(en)

1986-12-24
1988-07-07
Licentia Gmbh

SYSTEM FOR LANDING AID FOR AIRCRAFT WITH OWN ON-BOARD RADAR

DE102007019806A1
(en)

2007-04-26
2009-05-14
Esg Elektroniksystem- Und Logistik-Gmbh
Helicopter’s horizontal movement condition determining device, has ground detection device i.e. infrared camera, which is provided at helicopter, where device detects predetermined ground area

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Publication number
Priority date
Publication date
Assignee
Title

FR1404404A
(en)

1961-09-22
1965-07-02
Bristol Aircraft Ltd

Advanced missile guidance

FR1605307A
(en)

1964-06-23
1974-08-02

FR2113939B1
(en)

1970-11-13
1974-09-27
Saab Scania Ab

DE2238615C2
(en)

1972-08-05
1974-03-07
Messerschmitt-Boelkow-Blohm Gmbh, 8000 Muenchen

On-board autonomous bad weather landing procedure

1976

1976-04-29
FR
FR7612735A
patent/FR2353893A1/en
active
Granted

1977

1977-04-25
GB
GB17137/77A
patent/GB1572474A/en
not_active
Expired

1977-04-27
DE
DE2718698A
patent/DE2718698C2/en
not_active
Expired

Cited By (2)

* Cited by examiner, † Cited by third party

Publication number
Priority date
Publication date
Assignee
Title

US9891632B1
(en)

2016-08-15
2018-02-13
The Boeing Company
Point-and-shoot automatic landing system and method

US20180046202A1
(en)

2016-08-15
2018-02-15
The Boeing Company
Point-and-shoot automatic landing system and method

Also Published As

Publication number
Publication date

FR2353893B1
(en)

1982-08-27

DE2718698A1
(en)

1977-11-10

FR2353893A1
(en)

1977-12-30

DE2718698C2
(en)

1981-11-12

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