Patent EP0427431A2 successfully refreshed from Google Patents.
EP0427431A2
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Navigation systems
Assignee: Smiths Group PLC
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Filing: 1990-10-26
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Granted: —
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Expires: 2010-10-26
Abstract
Abstract An aircraft navigation system has a digital map store 31 of terrain features or man-made features in the region over which the aircraft is flying. Infra-red television cameras 1 to 3 view the surroundings of the aircraft. Their outputs are supplied to processors 21 to 23 in which the camera outputs are compared with a library 24 of features transformed according to the camera viewing angle. Information about those features identified is supplied to a correlator 30 which correlates the features against the map store to identify their location in the map and estimates the aircraft position as an output to a navigation computer 40. The system also indicates aircraft attitude whim may be independent of known-features, from observation of the horizon. Position information can also be provided by dead reckoning from a known initial position by monitoring the change in positional relationship of a feature from the initial position to that at a later position.
Inventors
- 👤 Roger Sean Fitzpatrick
- 👤 Keith Charles Rawlings
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 05:47
CPC Classifications
G; G09; G09B; G09B9/00; G09B9/02; G09B9/08; G09B9/24; G01; G01C; G01C21/00; G01C21/005
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
142 words
A vehicle navigation system, characterised in that the system includes a passive imaging sensor (1, 2, 3) arranged to view the surroundings of the vehicle and to provide an output in accordance therewith, a digital map store (31) of the region in which the vehicle is moving the map store containing information as to the location of individual features in the region, and that the system includes a unit (21, 22, 23) that identifies the presence of the features in the field of view of the sensor (1, 2, 3), and a unit (30) that identifies the position of the vehicle from the location of the features in the field of view of the sensor (1, 2′, 3) and the location of the features in the region as determined by the map store (31) and provides a position output in accordance therewith.
Claim 2
Dependent Claim
142 words
A vehicle navigation system, characterised in that the system includes a passive imaging sensor (1, 2, 3) arranged to view the surroundings of the vehicle and to provide an output in accordance therewith, a digital map store (31) of the region in which the vehicle is moving the map store containing information as to the location of individual features in the region, and that the system includes a unit (21, 22, 23) that identifies the presence of the features in the field of view of the sensor (1, 2, 3), and a unit (30) that identifies the position of the vehicle from the location of the features in the field of view of the sensor (1, 2′, 3) and the location of the features in the region as determined by the map store (31) and provides a position output in accordance therewith.
Claim 3
Dependent Claim
46 words
A vehicle navigation system according to Claim 1, characterised in that the map store (31) contains information in plan as to the location of the features, and that the system performs a transformation in perspective according to the viewing angle of the sensor (1, 2, 3).
Claim 4
Dependent Claim
48 words
A vehicle navigation system according to Claim 2, characterised in that the system includes a scan controller (4) for the sensor (1, 2, 3), and that the system performs the transformation in accordance with an output from the scan controller (4) and an output representative of vehicle attitude.
Claim 5
Dependent Claim
68 words
A vehicle navigation system according to any one of the preceding claims, characterised in that the system includes a unit (92) for entering to the system information as to an initial position of the vehicle when the vehicle is at a known position, and that the system updates the position of the vehicle from the known position in accordance with the output of the sensor (1, 2, 3).
Claim 6
Dependent Claim
100 words
A vehicle navigation system including a passive imaging sensor arranged to view the surroundings of the vehicle and to provide an output in accordance therewith, characterised in that the system includes a unit (92) for entering information of an initial position of the vehicle, and that the system monitors the change in positional relationship of the vehicle with respect to a feature in the field of view of the imaging sensor (1, 2, 3) from the initial position to a later position, and estimates the later position by dead reckoning from the initial position and the change in positional relationship.
Claim 7
Dependent Claim
100 words
A vehicle navigation system including a passive imaging sensor arranged to view the surroundings of the vehicle and to provide an output in accordance therewith, characterised in that the system includes a unit (92) for entering information of an initial position of the vehicle, and that the system monitors the change in positional relationship of the vehicle with respect to a feature in the field of view of the imaging sensor (1, 2, 3) from the initial position to a later position, and estimates the later position by dead reckoning from the initial position and the change in positional relationship.
Claim 8
Dependent Claim
45 words
A vehicle navigation system according to any one of the preceding claims, characterised in that the system derives an indication of the rate of change of viewing angle of a feature, and that the system utilizes the indication in identifying the position of the vehicle.
Claim 9
Dependent Claim
44 words
A vehicle navigation system according to any one of the preceding claims, characterised in that the system derives an indication of the rate of change of viewing angle of a feature, and that the system provides an indication of vehicle motion in accordance therewith.
Claim 10
Dependent Claim
44 words
A vehicle navigation system for an aircraft according to any one of the preceding claims, characterised in that the system provides an indication of roll of the aircraft by monitoring changes in the angular position of the horizon to the side of the aircraft.
Claim 11
Dependent Claim
45 words
A vehicle navigation system for an aircraft according to any one of the preceding claims, characterised in that the system provides an indication of the pitch of the aircraft by monitoring changes in the angular position of the horizon fore or aft of the aircraft.
Claim 12
Dependent Claim
64 words
A vehicle navigation system according to any one of the preceding claims, characterised in that the system identifies a feature absent from the map store (31) but which complies with rules delineating shaped features, that the system derives an indication of the rate of change of viewing angle of the feature, and that the system provides an indication of vehicle motion in accordance therewith.
Claim 13
Dependent Claim
44 words
A vehicle navigation system according to any one of the preceding claims, characterised in that the system includes an inertial navigation system (62), and that the position output is supplied to the inertial navigation system (62) to update information in the inertial navigation system.
Claim 14
Dependent Claim
80 words
A vehicle navigation system according to any one of the preceding claims, characterised in that the system provides an output in respect of vehicle movement relative to the ground, that the system includes an air data system (61) that provides an output indicative of the vehicle movement relative to the air, and that the navigation system provides an output indicative of wind speed and direction in accordance with the difference between the ground movement output and the air movement output.
Claim 15
Dependent Claim
61 words
A vehicle navigation system for an aircraft according to any one of the preceding claims, characterised in that the system includes an air data system (61) that provides an output representative of air speed, and that the system provides an output indicative of height of the aircraft from the angular rate of displacement of a ground feature relative to the aircraft.
References Cited (Backward Citations)
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