US3636336A
Expired / Lapsed
US
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Digital function generator for collision avoidance system
Assignee: Bendix Corp
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Filing: 1969-09-16
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Granted: 1972-01-18
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Expires: 1989-09-16
Abstract
Abstract Each pulse in a pulse train resets a counter to a predetermined initial state. A frequency generator generates a plurality of timing signals each of which comprises a different predetermined frequency. A gating means controlled by the state of the counter selects one of the timing signals to count down the counter. The state of the counter at the time of counter reset is thus related to the pulse repetition frequency of the pulses. Scaling of the system parameters permits the system to generate a sequence of straight line segments which approximate a desired function. In particular, proper scaling of the system parameters permits the system to operate as a digital altitude rate generator if the pulses represent fixed values of altitude change.
Inventors
- 👤 Samuel R Everett
- 👤 Wayne G Shear
- 👤 Jorge E Ardila
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 20:07
CPC Classifications
G; G01; G01S; G01S11/00; G01S11/02; G01S11/08; G06; G06F; G06F1/00; G06F1/02; G06F7/00; G06F7/60; G06F7/68
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
104 words
A function generator for computing the pulse repetition frequency between adjacent pulses in a pulse train comprising: means for generating a crossover signal upon detection of each said pulse; counting means reset to a predetermined initial state by said crossover signals, said counting means being strobed by timing signals; means for generating a plurality of said timing signals, each having a predetermined frequency; gating means responsive to the instantaneous state of said counting means for applying one out of said plurality of timing signals to said counting means; and, means responsive to said crossover signals for determining the instantaneous state of said counting means.
Claim 2
Dependent Claim
104 words
A function generator for computing the pulse repetition frequency between adjacent pulses in a pulse train comprising: means for generating a crossover signal upon detection of each said pulse; counting means reset to a predetermined initial state by said crossover signals, said counting means being strobed by timing signals; means for generating a plurality of said timing signals, each having a predetermined frequency; gating means responsive to the instantaneous state of said counting means for applying one out of said plurality of timing signals to said counting means; and, means responsive to said crossover signals for determining the instantaneous state of said counting means.
Claim 3
Dependent Claim
36 words
A function generator as recited in claim 1 wherein said pulses are generated by the change of state of a digital altimeter and wherein said means for generating a crossover signal comprises a pulse edge detector.
Claim 4
Dependent Claim
41 words
A function generator as recited in claim 2 with additionally means responsive to the change of state of the least significant bit and the least significant bit +1 contained in said altimeter for determining whether said altitude is increasing or decreasing.
Claim 5
Dependent Claim
40 words
A function generator as recited in claim 1 wherein said means for determining the instantaneous state of said counting means comprises a memory means for reproducing therein in response to said crossover signal said instantaneous state of said counting means.
Claim 6
Dependent Claim
27 words
A function generator as recited in claim 4 wherein said counting means comprises a binary counter with the count therein being arranged in parallel by bit format.
Claim 7
Dependent Claim
32 words
A function generator as recited in claim 5 wherein said timing signal generator comprises a plurality of digital dividers for deriving said plurality of timing signals from a single master timing signal.
Claim 8
Dependent Claim
104 words
Means for instantaneously calculating the rate of altitude change of an aircraft wherein end point signals are produced at the end points of predetermined standard altitude increments, comprising: counting means for counting pulses and which is reset to a predetermined initial state by each of said end point signals; a source of pulses to be counted by said counting means, the pulse repetition frequency of said pulses being related to the count contained in said counting means; and, means responsive to said end point signals for determining the instantaneous state of said counting means, said state as determined being said rate of altitude change.
Claim 9
Dependent Claim
104 words
Means for instantaneously calculating the rate of altitude change of an aircraft wherein end point signals are produced at the end points of predetermined standard altitude increments, comprising: counting means for counting pulses and which is reset to a predetermined initial state by each of said end point signals; a source of pulses to be counted by said counting means, the pulse repetition frequency of said pulses being related to the count contained in said counting means; and, means responsive to said end point signals for determining the instantaneous state of said counting means, said state as determined being said rate of altitude change.
Claim 10
Dependent Claim
18 words
Means as recited in claim 7 with additionally means for determining whether said altitude is increasing or decreasing.
Claim 11
Dependent Claim
99 words
Means as recited in claim 7 wherein aircraft altitude is stored in binary form in a binary counter, the number in said binary counter increasing when said altitude changes a fixed incremental amount in one direction and the number in said binary counter decreasing when said altitude changes a fixed incremental amount in the other direction, said calculating means additionally including means examining the state and change of state of the least significant bit and least significant bit plus one for generating a signal indicative of whether said altitude as stored in said binary counter is increasing or decreasing.
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) | 1975-01-17 | 1975-07-19 | 1976-01-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-17 | 1979-07-19 | 1980-01-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-17 | 1983-07-19 | 1984-01-18 | $7700.00 | Window Closed / Lapsed |