US3831010A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Area navigation computer
Assignee: RTX Corp
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Filing: 1973-06-04
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Granted: 1974-08-20
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Expires: 1993-06-04
Abstract
Abstract Digital signals relating to the north reference and variable phase components of the output of the VOR receiver are used along with slant range corrected output of distance measuring equipment to generate a synthetic, stepped sinewave representing the phasor from the VOR ground station to the aircraft. Stored digital waypoint distance (Rho) and bearing are combined with north reference signals to generate a synthetic, stepped sinewave representing the phasor of the VOR to a selected waypoint. The aircraft phasor is subtracted from the waypoint phasor and the resultant passed through a low pass filter, thereby providing a sinewave, the amplitude of which represents the distance from the aircraft to the waypoint and the phase of which represents the bearing of the aircraft track to the waypoint with respect to north, which comprises the phasor, or vector, to the waypoint. This phasor is resolved into X and Y components (arbitrarily with respect to north) each component then being constant slew rate filtered, and, with north reference signals, synthetic phasors are recreated, summed and filtered so as to provide a slew rate filtered phasor representing the vector from the aircraft to the waypoint, the magnitude of which is used to drive a distance to waypoint indicator, the phasor being combined with OBS track angle information to provide cross track error and to/from indications.
Inventors
- 👤 J Games
- 👤 C Casper
- 👤 B Kupersmith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 07:05
CPC Classifications
G; G01; G01S; G01S1/00; G01S1/02
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
257 words
An aircraft area navigation computer for use in conjunction with radio navigation ground stations, comprising: means for providing clock signals the timing of which are indicative of the bearing of an aircraft to a radio navigation ground station and for providing a signal the magnitude of which is indicative of the distance of an aircraft to the ground station; means responsive to said aircraft bearing and distance signals for synthesizing a stepped sinusoid the steps of which are synchronized to said aircraft bearing signals and the maximum amplitude of which is a function of said aircraft distance signal, thereby approximating a phasor representative of the vector position of the aircraft with respect to the ground station; means for developing clock signals the timing of which are representative of the bearing of a designated waypoint with respect to the ground station and for developing a signal the magnitude of which is a representation of the distance between the designated waypoint and the ground station; means responsive to said waypoint bearing and distance signals for synthetically generating a stepped sinusoid the steps of which are synchronized to said waypoint bearing signals and the maximum amplitude of which is a function of said waypoint distance signal, thereby approximating a phasor representative of the vector position of the waypoint with respect to the ground station; and means responsive to both said stepped sinusoids, including vector summation means and low pass filtering means, for providing a substantially pure sinusoidal phasor representing the vector position of the aircraft with respect to the waypoint.
Claim 2
Dependent Claim
257 words
An aircraft area navigation computer for use in conjunction with radio navigation ground stations, comprising: means for providing clock signals the timing of which are indicative of the bearing of an aircraft to a radio navigation ground station and for providing a signal the magnitude of which is indicative of the distance of an aircraft to the ground station; means responsive to said aircraft bearing and distance signals for synthesizing a stepped sinusoid the steps of which are synchronized to said aircraft bearing signals and the maximum amplitude of which is a function of said aircraft distance signal, thereby approximating a phasor representative of the vector position of the aircraft with respect to the ground station; means for developing clock signals the timing of which are representative of the bearing of a designated waypoint with respect to the ground station and for developing a signal the magnitude of which is a representation of the distance between the designated waypoint and the ground station; means responsive to said waypoint bearing and distance signals for synthetically generating a stepped sinusoid the steps of which are synchronized to said waypoint bearing signals and the maximum amplitude of which is a function of said waypoint distance signal, thereby approximating a phasor representative of the vector position of the waypoint with respect to the ground station; and means responsive to both said stepped sinusoids, including vector summation means and low pass filtering means, for providing a substantially pure sinusoidal phasor representing the vector position of the aircraft with respect to the waypoint.
Claim 3
Dependent Claim
164 words
An aircraft area navigation computer for use in conjunction with radio navigation ground stations, comprising: first means for generating signals representative of the bearing and distance of the aircraft to a radio navigation ground station; second means for presenting signals representative of the bearing and distance of a desired waypoint to the ground station; means responsive to said first and second means for generating a phasor signal representing the vector position of the aircraft with respect to the desired waypoint; resolution means responsive to said phasor signal for generating signals representative of the resolution of said phasor into a pair of orthogonal components; constant slew rate filter means responsive to said orthogonal component signals for providing a pair of corresponding rate-limited orthogonal component signals; and means responsive to said rate-limited orthogonal component signals for generating a rate-limited phasor signal representative of the vector sum of said rate-limited orthogonal component signals, said phasor signal representing the vector position of the aircraft to the desired waypoint.
Claim 4
Dependent Claim
164 words
An aircraft area navigation computer for use in conjunction with radio navigation ground stations, comprising: first means for generating signals representative of the bearing and distance of the aircraft to a radio navigation ground station; second means for presenting signals representative of the bearing and distance of a desired waypoint to the ground station; means responsive to said first and second means for generating a phasor signal representing the vector position of the aircraft with respect to the desired waypoint; resolution means responsive to said phasor signal for generating signals representative of the resolution of said phasor into a pair of orthogonal components; constant slew rate filter means responsive to said orthogonal component signals for providing a pair of corresponding rate-limited orthogonal component signals; and means responsive to said rate-limited orthogonal component signals for generating a rate-limited phasor signal representative of the vector sum of said rate-limited orthogonal component signals, said phasor signal representing the vector position of the aircraft to the desired waypoint.
Claim 5
Dependent Claim
73 words
A navigation computer according to claim 2 further comprising: means for developing a signal indicative of a change in the desired waypoint; and wherein said constant slew rate filter means further comprises means responsive to said waypoint change signal to decrease the time constant of said constant slew rate filter means, thereby to increase the maximum rate limitation applied to said orthogonal component signals in the generation of said rate-limited orthogonal component signals.
Claim 6
Dependent Claim
201 words
The combination of: means providing a pair of signals representing orthogonal components of a phasor indicative of the vector position of an aircraft with respect to a designated waypoint; a pair of active rate limiting filters, each including an amplifier, each normally operable to provide a preselected limit on the rate of change of an output signal with respect to an input signal, each including selectively operable means to increase substantially the rate at which the output signal may change with respect to the input signal; means responsive to the output signal and the input signal of each of said amplifiers for comparing the difference between the input and output of each amplifier with a predetermined limit and for generating an excess signal in response to said difference being greater than said predetermined limit; and timing means responsive to said excess signal for generating a signal for operating said selectively operable means in each of said active filters for a predetermined time interval following the occurrence of said excess signal and including means responsive to a signal indicative of a change in designated waypoint applied thereto for substantially instantaneously causing the generation of said operation signal for a predetermined time interval.
Claim 7
Dependent Claim
201 words
The combination of: means providing a pair of signals representing orthogonal components of a phasor indicative of the vector position of an aircraft with respect to a designated waypoint; a pair of active rate limiting filters, each including an amplifier, each normally operable to provide a preselected limit on the rate of change of an output signal with respect to an input signal, each including selectively operable means to increase substantially the rate at which the output signal may change with respect to the input signal; means responsive to the output signal and the input signal of each of said amplifiers for comparing the difference between the input and output of each amplifier with a predetermined limit and for generating an excess signal in response to said difference being greater than said predetermined limit; and timing means responsive to said excess signal for generating a signal for operating said selectively operable means in each of said active filters for a predetermined time interval following the occurrence of said excess signal and including means responsive to a signal indicative of a change in designated waypoint applied thereto for substantially instantaneously causing the generation of said operation signal for a predetermined time interval.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-08-19 | 1978-02-18 | 1978-08-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-19 | 1982-02-18 | 1982-08-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-19 | 1986-02-18 | 1986-08-20 | $7700.00 | Window Closed / Lapsed |