Patent US3147640A successfully refreshed from Google Patents.
Patent US3843076A successfully refreshed from Google Patents.
US3843076A
Expired / Lapsed
US
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Projectile trajectory correction system
Assignee: Northrop Grumman Space and Mission Systems Corp
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Filing: 1972-01-03
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Granted: 1974-10-22
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Expires: 1992-01-03
Abstract
Abstract A system for correcting the terminal portion of the trajectory of a projectile in free fall so as to minimize the error between the actual and the intended impact point. The projectile may be an artillery rocket, cannon shell, or a similar ballistic body, which is caused to roll during its free fall trajectory. The intended target or impact point is illuminated by a light source and this light is received at the projectile by a sensor consisting of optics and a plurality of detectors arranged in a plane, and along an annular area. The sensor is made to have a hollow conical field of view, such that the ground area in the vicinity of the target covered by the field of view is reduced as the projectile approaches the target. Thus, when the target appears in the field of view its image will fall on one of the detectors to determine the polar coordinates of the target with respect to the uncorrected impact point. Electronic means are provided for firing a lateral thruster at a predetermined time commensurate with the polar position of the detector that has detected the target image. This will apply a lateral impulse to the projectile to change the trajectory so as to minimize the terminal error.
Inventors
- 👤 R King
- 👤 W Massey
- 👤 J Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 08:46
CPC Classifications
F; F41; F41G; F41G7/00; F41G7/20; F41G7/22; F41G7/222; F41G7/226; F41G7/2273; F41G7/2293; F42; F42B; F42B10/00; F42B10/60; F42B10/66; F42B10/661
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
146 words
The method of correcting the terminal portion of the trajectory of a projectile in free fall and rotating about its axis, the projectile being directed toward a target, said method comprising the steps of: a. illuminating the target; b. detecting the light reflected from the target within a predetermined hollow cone extending between the rotating projectile and the ground as the projectile approaches the target; c. applying a single lateral impulse to the projectile in accordance with the image of the light reflected from the target; and d. determining the polar coordinates of the image of the target received at the projectile, thereby to determine the instant of time when the single lateral impulse is applied to the projectile, whereby the direction of the impulse applied to the projectile and the instant the impulse is applied is determined by the polar coordinates of the target image.
Claim 2
Independent Claim
146 words
The method of correcting the terminal portion of the trajectory of a projectile in free fall and rotating about its axis, the projectile being directed toward a target, said method comprising the steps of: a. illuminating the target; b. detecting the light reflected from the target within a predetermined hollow cone extending between the rotating projectile and the ground as the projectile approaches the target; c. applying a single lateral impulse to the projectile in accordance with the image of the light reflected from the target; and d. determining the polar coordinates of the image of the target received at the projectile, thereby to determine the instant of time when the single lateral impulse is applied to the projectile, whereby the direction of the impulse applied to the projectile and the instant the impulse is applied is determined by the polar coordinates of the target image.
Claim 3
Independent Claim
148 words
A system for correcting the terminal portion of the trajectory of a projectile directed toward a target, said system comprising: a. a light source for illuminating the target; b. means for causing said projectile to roll at a predetermined rate; c. a plurality of detectors disposed on said rolling projectile and responsive to the light of said light source reflected by the target, said detectors being disposed in a plane and along an annular area; d. means associated with said detectors for limiting the field of view of said detectors to a cone of predetermined angle; e. a thruster disposed on said projectile for supplying to said projectile a single predetermined lateral impulse; and f. electronic means coupled to said detectors and said thruster for energizing said thruster upon a particular one of the rotating detectors receiving light from the illuminated target within the field of view thereof.
Claim 4
Independent Claim
148 words
A system for correcting the terminal portion of the trajectory of a projectile directed toward a target, said system comprising: a. a light source for illuminating the target; b. means for causing said projectile to roll at a predetermined rate; c. a plurality of detectors disposed on said rolling projectile and responsive to the light of said light source reflected by the target, said detectors being disposed in a plane and along an annular area; d. means associated with said detectors for limiting the field of view of said detectors to a cone of predetermined angle; e. a thruster disposed on said projectile for supplying to said projectile a single predetermined lateral impulse; and f. electronic means coupled to said detectors and said thruster for energizing said thruster upon a particular one of the rotating detectors receiving light from the illuminated target within the field of view thereof.
Claim 5
Dependent Claim
25 words
A system as defined in claim 2 wherein said detectors extend over a portion only of said annular area to provide a detector-free annular segment.
Claim 6
Dependent Claim
73 words
A system as defined in claim 3 wherein electronic means is connected to each of said detectors for generating an electronic output signal in response to light falling on a particular one of said detectors, said electronic means being coupled to said thruster for energizing it at an instant of time depending on the position of said particular detector with respect to said segment for minimizing the error of the projectile''s impact point.
Claim 7
Independent Claim
215 words
A system for correcting the terminal portion of the trajectory of a projectile in free fall directed toward a target, said system comprising: a. a light source for illuminating the target; b. means for causing said projectile to roll at a predetermined rate; c. a plurality of detectors, each for detecting the light reflected by the illuminated target, said detectors being arranged in a plane along an annular area extending over a portion only of said annular area to provide a detector-free annular segment; d. means for limiting the field of view of said detectors to a hollow cone of predetermined interior and exterior angles, whereby said cone covers successively smaller areas as said rolling projectile approaches ground; e. a thruster connected to said projectile for imparting thereto a predetermined lateral impulse; f. electronic means connected to each of said detectors for creating an output signal in response to the image of the illuminated target falling on a particular one of said detectors, said electronic means being coupled to said thruster for energizing said thruster at an instant of time depending on the angular position of said particular detector with respect to said segment, thereby to impart a lateral impulse to said projectile in a direction to minimize the errors of the projectile''s impact point.
Claim 8
Independent Claim
215 words
A system for correcting the terminal portion of the trajectory of a projectile in free fall directed toward a target, said system comprising: a. a light source for illuminating the target; b. means for causing said projectile to roll at a predetermined rate; c. a plurality of detectors, each for detecting the light reflected by the illuminated target, said detectors being arranged in a plane along an annular area extending over a portion only of said annular area to provide a detector-free annular segment; d. means for limiting the field of view of said detectors to a hollow cone of predetermined interior and exterior angles, whereby said cone covers successively smaller areas as said rolling projectile approaches ground; e. a thruster connected to said projectile for imparting thereto a predetermined lateral impulse; f. electronic means connected to each of said detectors for creating an output signal in response to the image of the illuminated target falling on a particular one of said detectors, said electronic means being coupled to said thruster for energizing said thruster at an instant of time depending on the angular position of said particular detector with respect to said segment, thereby to impart a lateral impulse to said projectile in a direction to minimize the errors of the projectile''s impact point.
Claim 9
Dependent Claim
34 words
A system as defined in claim 5 wherein said thruster is disposed circumferentIally at such an angle with respect to said segment as to correct for the buildup and decay of the thruster''s thrust.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-10-21 | 1978-04-22 | 1978-10-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-21 | 1982-04-22 | 1982-10-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-21 | 1986-04-22 | 1986-10-22 | $7700.00 | Window Closed / Lapsed |