CA2002039A1 - Helmet pointing apparatus - Google Patents
Helmet pointing apparatusInfo
- Publication number
- CA2002039A1 CA2002039A1 CA002002039A CA2002039A CA2002039A1 CA 2002039 A1 CA2002039 A1 CA 2002039A1 CA 002002039 A CA002002039 A CA 002002039A CA 2002039 A CA2002039 A CA 2002039A CA 2002039 A1 CA2002039 A1 CA 2002039A1
- Authority
- CA
- Canada
- Prior art keywords
- helmet
- light sources
- light
- arrival
- sensors
- Prior art date
- 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.)
- Abandoned
Links
- 230000003287 optical effect Effects 0.000 claims abstract description 4
- 230000005672 electromagnetic field Effects 0.000 description 2
- 238000012952 Resampling Methods 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000005070 sampling Methods 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000013598 vector Substances 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F41—WEAPONS
- F41G—WEAPON SIGHTS; AIMING
- F41G3/00—Aiming or laying means
- F41G3/22—Aiming or laying means for vehicle-borne armament, e.g. on aircraft
- F41G3/225—Helmet sighting systems
-
- 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
- G01S5/00—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations
- G01S5/16—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations using electromagnetic waves other than radio waves
- G01S5/163—Determination of attitude
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- General Physics & Mathematics (AREA)
- Radar, Positioning & Navigation (AREA)
- Remote Sensing (AREA)
- Aviation & Aerospace Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Length Measuring Devices By Optical Means (AREA)
- Position Input By Displaying (AREA)
Abstract
ABSTRACT
HELMET POINTING APPARATUS
A helmet pointing apparatus enabling a pilots line of sight to be determined relative to a fixed coordinate system within a cockpit comprises at least 3 LED light sources 10,12,14 mounted on the helmet 2 and at least 2 direction-of-arrival optical sensors 6,8 mounted fixedly in the cockpit. The direction of arrival of the light from the sources to the sensors can be employed to compute the orientation of the helmet. The sensors are of a "mirror-cube" type.
HELMET POINTING APPARATUS
A helmet pointing apparatus enabling a pilots line of sight to be determined relative to a fixed coordinate system within a cockpit comprises at least 3 LED light sources 10,12,14 mounted on the helmet 2 and at least 2 direction-of-arrival optical sensors 6,8 mounted fixedly in the cockpit. The direction of arrival of the light from the sources to the sensors can be employed to compute the orientation of the helmet. The sensors are of a "mirror-cube" type.
Description
~`` ~
HELMET POINTING APPARATUS
This invention relates to an apparatus for determining the line of s~ght and optionally orientation in space of a helmet and particularly, but not exclusively, to helmets as worn by military personnel.
Military helmet po~nting systems are known, and represent an alternative solution to the aiming of guns or ;~
missiles. For example, the traditional method for a fighterpilot to aim a missile at a desired target relies ~
on the pilot aligning the aircraft generally in the ~ ~-direction of the target by use of an aiming graticule ~ -displayed in front of him; this is known as boresight aiming. With a helmet pointing system, the pilot merely `
looks in the direction of the target (which could be off-axis in relation to the aircraft direction), aided by an aiming graticule on, for instance, the helmet visor. A
sensing system is provided in the cockpit for determining the line of sight and optionally the orientation in space `~
of the helmet, and for computing the geometrical relationship between the helmet line of sight axis and the missile longitudinal axis. The latter is typically the ~ ~;
same as the aircraft longitudinal axis when the missile waits to be fired. The off-axis relationship is passed to the guidance system of the missile, which then has the neces~ary information for heading in the direction of the ``;
off-axi~ target when fired. Such helmet pointing systems can be similarly used for controlling gun aiming (e.g. in helicopters or tanks) or even in non-military environments. One example of the latter would be the use of such a he~met in crowd control: the direction of pointing of a remotely-controlled camera could be com~anded by an operator wearing such a helmet and viewing ~;
the crowd from an environment which was equipped with the necessary optics and electronics.
One known helmet po~nting system relies on the -, i~
HELMET POINTING APPARATUS
This invention relates to an apparatus for determining the line of s~ght and optionally orientation in space of a helmet and particularly, but not exclusively, to helmets as worn by military personnel.
Military helmet po~nting systems are known, and represent an alternative solution to the aiming of guns or ;~
missiles. For example, the traditional method for a fighterpilot to aim a missile at a desired target relies ~
on the pilot aligning the aircraft generally in the ~ ~-direction of the target by use of an aiming graticule ~ -displayed in front of him; this is known as boresight aiming. With a helmet pointing system, the pilot merely `
looks in the direction of the target (which could be off-axis in relation to the aircraft direction), aided by an aiming graticule on, for instance, the helmet visor. A
sensing system is provided in the cockpit for determining the line of sight and optionally the orientation in space `~
of the helmet, and for computing the geometrical relationship between the helmet line of sight axis and the missile longitudinal axis. The latter is typically the ~ ~;
same as the aircraft longitudinal axis when the missile waits to be fired. The off-axis relationship is passed to the guidance system of the missile, which then has the neces~ary information for heading in the direction of the ``;
off-axi~ target when fired. Such helmet pointing systems can be similarly used for controlling gun aiming (e.g. in helicopters or tanks) or even in non-military environments. One example of the latter would be the use of such a he~met in crowd control: the direction of pointing of a remotely-controlled camera could be com~anded by an operator wearing such a helmet and viewing ~;
the crowd from an environment which was equipped with the necessary optics and electronics.
One known helmet po~nting system relies on the -, i~
- 2 -. _ transmission of electromagnetic field vectors from a fixed antenna to a receiving antenna on the helmet. The transmitted electromagnetic field provides a fixed reference in space, and as the helmet moves in the field the receiving antenna provides signals to a sensing unit which is able to compute the helmet orieatation relative to the fixed field. Such systems are descr$bed in, for example, US-A-4 287 809 and 4 394 831. A disadvantage of systems based on electromagnetism i8 that they are ~ -susceptible to unwanted influence from other magnetic -fields in the environment (e.g. in the aircraft cockpit).
With any helmet pointing system for use by a pilot, one difficulty is sampling the data relating to helmet position fast enough bearing in mind that the pilot's head is sometimes moving at a rate greater than 100 per ;~
second. Unless the system is capable of rapid resampling, helmet position errors will be introduced. The present invention relates to a helmet pointing system which ~
enables the data to be sampled rapidly and with an ;
accuracy suitable for use in the cockpit of, say, fighter aircxaft.
According to the invention, there is provided a helmet pointing apparatus which comprises a first plurality of light sources, a second plurality of direction-of-arrival sensors each for receiving a beam of light from the said light sources, either the first plurality or the second plurality being fixed to a helmet whose line of sight and, optionally, orientation it is desired to compute, and the other of said pluralitie~ -being fixed at fixed reference points, and mean~
responsive to signals received by said direction-of-arrival sensors for relating each respective signal to specific light sources, for computing the direction-of-arrival from any given sensor to any given light source, and for computing line-of-sight signals and "~ ~ .`', '~ ' ~ '' " 1~
With any helmet pointing system for use by a pilot, one difficulty is sampling the data relating to helmet position fast enough bearing in mind that the pilot's head is sometimes moving at a rate greater than 100 per ;~
second. Unless the system is capable of rapid resampling, helmet position errors will be introduced. The present invention relates to a helmet pointing system which ~
enables the data to be sampled rapidly and with an ;
accuracy suitable for use in the cockpit of, say, fighter aircxaft.
According to the invention, there is provided a helmet pointing apparatus which comprises a first plurality of light sources, a second plurality of direction-of-arrival sensors each for receiving a beam of light from the said light sources, either the first plurality or the second plurality being fixed to a helmet whose line of sight and, optionally, orientation it is desired to compute, and the other of said pluralitie~ -being fixed at fixed reference points, and mean~
responsive to signals received by said direction-of-arrival sensors for relating each respective signal to specific light sources, for computing the direction-of-arrival from any given sensor to any given light source, and for computing line-of-sight signals and "~ ~ .`', '~ ' ~ '' " 1~
optionally orientation siqnals with respect to the fixed reference points for said helmet.
Direction-of-arrival sensors (DOAS) are commercially available and these may be used in the invention. One known DOAS is termed a quadrant detector and consists of four planar photodetectors, one each d~sposed in the four --quadrants of a plane about imaginary X-Y axes. Any beam of light striking the detectors is first focussed by a ` ;~
lens. The actual direction of arrival of the light beam ~
determines precisely where, upon the four quadrants, the ~ --focussed beam strikes. The relative conduction of the four photodetectors can then be translated into a geometrical direction of arrival. Such a device is available from Integrated Photomatrix Ltd., Dorchester, UK
(part IPL 10130) and has a focussed light spot about 1 mm -in diameter.
A further DOAS replaces the four quadrant photodetectors with a CCD array. Again, depending upon ;
where the focussed beam strikes the array, the received `` `
signal can be translated into a direction of arrival. A
suitable CCD array is a Sony ICX021CL, which is a solid ;~
state image device designed for black/white TV. It has a focussed light spot about 20 ~Im in diameter. ~ ~
Preferable, however, the present invention employs -`
DOAS of the type described and claimed in our copending patent application of even date entitled ~Optical ;~
Sensor~. Most preferably each DOAS is of the ~ `-~mirror-cube~ type specifically described in said patent application. A copy of the specification of the latter application is attached for reference. An advantage of the ~mirror-cube~ type DOAS is that it can be manufactured `~
in min~ature format to give high accuracy, repeatability and sensitivity within the close confines of a pilot's ` ;`~
cockpit. i Preferred features of the invention will now be ~ '''"'`"'~''`'"' ' described, by way of example, with reference to the accompanying drawing, which illustrates schematically a preferred form of the invention as employed ~n the cockpit of an aircraft.
Referring to the drawing, a pilot's helmet 2 is shown disposed within the cockpit 4. The cockpit carries at least 2 DOAS 6,8 of the ~mirror-cube~ type already described. On the helmet is mounted at least 3 LED
(light-emitting diode) light sources 10,12,14.
The LEDs emit spherical light waves which are sensed -~
by the DOAS. The size of the DOAS relative to their distance from the LEDs is arranged to be sufficiently small that, for practical purposes, each DOAS can be considered to receive planar light waves from each LED.
The helmet is independent of the remainder of the ~ -system and includes a battery power supply for the LEDs -and for oscillators to tone modulate each LED at different frequencies. The DOAS receive the tone modulated light signals and discriminate between each LED by filtering the received signals. From each discriminated isignal the direction of arrival of the light beam (i.e. the direction in space from the DOAS to the LED in question) may be computed as described in the said copendinq patent application.
In a perfect system, the position ~n space of any one LED ought to be defined by the intersection of the computed directions-of-arrival from two spaced-apart DOAS
to the LED. In practice, these lines may not exactly coincide and it is convenient to choose, as the LED
position, the midpoint of the shortest line segment which ~oins two computed lines. With the poisitions in Qpace of three separate LEDs having been determined, it is then a simply trigonometric matter to translate these positions into the orientation of the helmet in space, and to the pilot's line of sight.
~, ~
I
Direction-of-arrival sensors (DOAS) are commercially available and these may be used in the invention. One known DOAS is termed a quadrant detector and consists of four planar photodetectors, one each d~sposed in the four --quadrants of a plane about imaginary X-Y axes. Any beam of light striking the detectors is first focussed by a ` ;~
lens. The actual direction of arrival of the light beam ~
determines precisely where, upon the four quadrants, the ~ --focussed beam strikes. The relative conduction of the four photodetectors can then be translated into a geometrical direction of arrival. Such a device is available from Integrated Photomatrix Ltd., Dorchester, UK
(part IPL 10130) and has a focussed light spot about 1 mm -in diameter.
A further DOAS replaces the four quadrant photodetectors with a CCD array. Again, depending upon ;
where the focussed beam strikes the array, the received `` `
signal can be translated into a direction of arrival. A
suitable CCD array is a Sony ICX021CL, which is a solid ;~
state image device designed for black/white TV. It has a focussed light spot about 20 ~Im in diameter. ~ ~
Preferable, however, the present invention employs -`
DOAS of the type described and claimed in our copending patent application of even date entitled ~Optical ;~
Sensor~. Most preferably each DOAS is of the ~ `-~mirror-cube~ type specifically described in said patent application. A copy of the specification of the latter application is attached for reference. An advantage of the ~mirror-cube~ type DOAS is that it can be manufactured `~
in min~ature format to give high accuracy, repeatability and sensitivity within the close confines of a pilot's ` ;`~
cockpit. i Preferred features of the invention will now be ~ '''"'`"'~''`'"' ' described, by way of example, with reference to the accompanying drawing, which illustrates schematically a preferred form of the invention as employed ~n the cockpit of an aircraft.
Referring to the drawing, a pilot's helmet 2 is shown disposed within the cockpit 4. The cockpit carries at least 2 DOAS 6,8 of the ~mirror-cube~ type already described. On the helmet is mounted at least 3 LED
(light-emitting diode) light sources 10,12,14.
The LEDs emit spherical light waves which are sensed -~
by the DOAS. The size of the DOAS relative to their distance from the LEDs is arranged to be sufficiently small that, for practical purposes, each DOAS can be considered to receive planar light waves from each LED.
The helmet is independent of the remainder of the ~ -system and includes a battery power supply for the LEDs -and for oscillators to tone modulate each LED at different frequencies. The DOAS receive the tone modulated light signals and discriminate between each LED by filtering the received signals. From each discriminated isignal the direction of arrival of the light beam (i.e. the direction in space from the DOAS to the LED in question) may be computed as described in the said copendinq patent application.
In a perfect system, the position ~n space of any one LED ought to be defined by the intersection of the computed directions-of-arrival from two spaced-apart DOAS
to the LED. In practice, these lines may not exactly coincide and it is convenient to choose, as the LED
position, the midpoint of the shortest line segment which ~oins two computed lines. With the poisitions in Qpace of three separate LEDs having been determined, it is then a simply trigonometric matter to translate these positions into the orientation of the helmet in space, and to the pilot's line of sight.
~, ~
I
- 5 ~
For greater accuracy, a larger number of DOAS and LEDs may be employed. It is also possible to reverse the positions of the LEDs and DOAS - so that the latter are upon the heLnet. This is less practical as it is likely `;~
to necessitate connecting the helmet to the aircraft's `~
electronic systems. ~-`
With the apparatus of the invention it is possible ,`~
to determine not only the line of sight of the pilot relative to the cockpit, but also the orientation of his -~
head about this line-of-sight. This latter information may, in fact, not be necessary if, for example, the line of sight is to be employed to fire a missile upon an off-aircraft-axis trajectory.
,. . ,~ ,~ ., ``"``' i '`,.`"`~` ',`'`~'.'.`
, `~'.', ' ~',' , .. .....
` .... `. -','`
`''",',,~ ~,.' .`~.: ~.,.`
'',''" :''~.
; ., ,. ~ . :;
For greater accuracy, a larger number of DOAS and LEDs may be employed. It is also possible to reverse the positions of the LEDs and DOAS - so that the latter are upon the heLnet. This is less practical as it is likely `;~
to necessitate connecting the helmet to the aircraft's `~
electronic systems. ~-`
With the apparatus of the invention it is possible ,`~
to determine not only the line of sight of the pilot relative to the cockpit, but also the orientation of his -~
head about this line-of-sight. This latter information may, in fact, not be necessary if, for example, the line of sight is to be employed to fire a missile upon an off-aircraft-axis trajectory.
,. . ,~ ,~ ., ``"``' i '`,.`"`~` ',`'`~'.'.`
, `~'.', ' ~',' , .. .....
` .... `. -','`
`''",',,~ ~,.' .`~.: ~.,.`
'',''" :''~.
; ., ,. ~ . :;
Claims (11)
1. A helmet pointing apparatus which comprises a first plurality of light sources, a second plurality of direction-of-arrival sensors each for receiving a beam of light from the said light sources, either the first plurality or the second plurality being fixed to a helmet whose line of sight and, optionally, orientation it is desired to compute, and the other of said pluralities being fixed at fixed reference points, and means responsive to signals received by said direction-of-arrival sensors for relating each respective signal to specific light sources, for computing the direction-of-arrival from any given sensor to any given light source, and for computing line-of-sight signals and optionally orientation signals with respect to the fixed reference points for said helmet.
2. An apparatus according to claim 1 wherein the first plurality is fixed to the helmet.
3. An apparatus according to claim 1 or 2 wherein each light source emits a beam of light uniquely identifiable from the other light sources.
4. An apparatus according to claim 3 which comprises means for modulating the beams of light emitted by the light sources.
5. An apparatus according to claim 4 wherein the relating means comprises filter means for discriminating between modulated signals received from said direction-of-arrival sensors.
6. An apparatus according to any of claims 1 to 5 which comprises at least three light sources and at least two optical sensors.
7. An apparatus according to any of claims 1 to 6 wherein the light sources are light-emitting diodes.
8. An apparatus according to any of claims 1 to 7 wherein each direction-of-arrival sensor comprises a mirror-cube type sensor.
9. An apparatus according to claim 8 wherein each sensor comprises a planar base and a three-dimensional body extending therefrom, said three-dimensional body being constituted by at least four planar contiguous reflective surfaces disposed such that the join lines of adjacent surfaces lie parallel to one another and perpendicular to the base, at least four optical sensors being disposed on the surface on said base, one for each reflective surface, each sensor extending outwardly on said base surface from the edge where its reflective surface contacts the base surface.
10. An apparatus according to claim 9 wherein said three-dimensional body is a rectangular parallelepiped.
11. An apparatus according to claim 10 wherein the parallelepiped is a cube.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB8825706A GB2239366A (en) | 1988-11-03 | 1988-11-03 | Helmet pointing apparatus |
| GB8825706.8 | 1988-11-03 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2002039A1 true CA2002039A1 (en) | 1990-05-03 |
Family
ID=10646228
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002002039A Abandoned CA2002039A1 (en) | 1988-11-03 | 1989-11-02 | Helmet pointing apparatus |
Country Status (5)
| Country | Link |
|---|---|
| CA (1) | CA2002039A1 (en) |
| DE (1) | DE3936700A1 (en) |
| FR (1) | FR2657154A1 (en) |
| GB (1) | GB2239366A (en) |
| IT (1) | IT1237026B (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2686439A1 (en) * | 1992-01-20 | 1993-07-23 | Data Stream Corp | Wireless input peripheral element for computer |
| GB2284957B (en) * | 1993-12-14 | 1998-02-18 | Gec Marconi Avionics Holdings | Optical systems for the remote tracking of the position and/or orientation of an object |
| DE4412073A1 (en) * | 1994-04-08 | 1995-10-12 | Moeller J D Optik | Surgical microscope unit |
| SE506517C3 (en) * | 1995-06-19 | 1998-02-05 | Jan G Faeger | Procedure for saturating objects and apparatus for obtaining a set of objects with kaenda laegen |
| GB2332052B (en) * | 1997-12-04 | 2002-01-16 | Olivetti Res Ltd | Detection system for determining orientation information about objects |
| RU2208758C2 (en) * | 2000-11-22 | 2003-07-20 | Казенное предприятие "Центральное конструкторское бюро "Арсенал" | Helmet-mounted target designating system |
| DE10226398B4 (en) * | 2002-06-13 | 2012-12-06 | Carl Zeiss Ag | Method and device for detecting the position of an object in space |
| FR2905455B1 (en) * | 2006-09-05 | 2008-10-17 | Thales Sa | METHOD FOR DETECTING THE ORIENTATION AND POSITION OF AN OBJECT IN THE SPACE |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2399033A1 (en) * | 1977-07-29 | 1979-02-23 | Thomson Csf | DEVICE FOR LOCATING A RADIANT SOURCE AND DIRECTION TRACKING SYSTEM INCLUDING SUCH A DEVICE |
-
1988
- 1988-11-03 GB GB8825706A patent/GB2239366A/en not_active Withdrawn
-
1989
- 1989-10-31 IT IT04850489A patent/IT1237026B/en active IP Right Grant
- 1989-11-02 CA CA002002039A patent/CA2002039A1/en not_active Abandoned
- 1989-11-03 DE DE3936700A patent/DE3936700A1/en not_active Withdrawn
- 1989-11-03 FR FR8914407A patent/FR2657154A1/en not_active Withdrawn
Also Published As
| Publication number | Publication date |
|---|---|
| IT8948504A1 (en) | 1991-05-01 |
| FR2657154A1 (en) | 1991-07-19 |
| IT1237026B (en) | 1993-05-13 |
| DE3936700A1 (en) | 1991-01-03 |
| GB2239366A (en) | 1991-06-26 |
| IT8948504A0 (en) | 1989-10-31 |
| GB8825706D0 (en) | 1990-06-13 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP1203285B1 (en) | Head tracker system | |
| EP0294101B1 (en) | System for measuring the angular displacement of an object | |
| US5396243A (en) | Infrared laser battlefield identification beacon | |
| US4439755A (en) | Head-up infinity display and pilot's sight | |
| US4111555A (en) | Apparatus for measuring the angular displacement of a body | |
| US7046215B1 (en) | Head tracker system | |
| US5114227A (en) | Laser targeting system | |
| US10408574B2 (en) | Compact laser and geolocating targeting system | |
| US5040885A (en) | Telescope designator | |
| US6491253B1 (en) | Missile system and method for performing automatic fire control | |
| US4946277A (en) | Opto-electronic device for detecting and locating a radiant source | |
| WO2008060662A2 (en) | Dual fov imaging semi-active laser system | |
| EP1515162B1 (en) | Device for detecting optical and optoelectronic objects | |
| US7773202B2 (en) | Laser spot tracker and target identifier | |
| US4097155A (en) | Target locating system | |
| CA2002039A1 (en) | Helmet pointing apparatus | |
| EP0235944B1 (en) | Optical aiming device | |
| US4562769A (en) | Spatially modulated, laser aimed sighting system for a ballistic weapon | |
| EP0433538A2 (en) | Optic-electronic telemetry device with variable base | |
| US6249589B1 (en) | Device for passive friend-or-foe discrimination | |
| JP2025530731A (en) | Observation optics with software functions implemented by the enabler | |
| GB2347573A (en) | Head tracker system | |
| RU2242019C2 (en) | Method for determination of co-ordinates of distant object on terrain and device for its realization | |
| EP4520211A1 (en) | Identification friend or foe apparatus | |
| US4179085A (en) | Optical boresight method for nutating system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Discontinued |