US3586268A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Instrument flight system
Assignee: Individual
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Filing: 1969-04-04
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Granted: 1971-06-22
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Expires: 1989-04-04
Abstract
Abstract An aircraft control system particularly useful during approach operations. In the approach mode, a pitch command computer produces a pitch command signal for controlling an aircraft''s pitch to maintain a desired angle of attack, and hence a desired airspeed; and a thrust command computer produces a thrust command signal for controlling the flight path angle to maintain an aircraft on a desired glide path for landing. The command signals control either instrument indicators which visually display the appropriate information to the pilot for manual operation or alternatively control an autopilot and autothrottle for automatic operation of the aircraft. If the aircraft is below the desired glide path but at the desired airspeed, athrust command computer indicates the direction necessary to change the thrust to increase the aircraft''s flight path angle so that the aircraft returns to the glide path. As the thrust level is varied according to the thrust command signal, an angle of attack sensor senses the changes in the angle of attack of the aircraft and a pitch command computer produces a pitch command signal to maintain the angle of attack at a desired level determined from the desired airspeed. In addition to the approach mode, the control system offers advantages in the take off, climb, hold, maximum range, severe turbulence, and descent modes of an aircraft''s operation. The cruise mode operates similar to prior art systems.
Inventors
- 👤 William W Melvin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 23:10
CPC Classifications
G; G05; G05D; G05D1/00; G05D1/04; G05D1/06; G05D1/0607; G05D1/0653; G05D1/0676; G05D1/0615; G05D1/0638
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
122 words
The method of controlling an aircraft in an approach mode with respect to maintaining a desired glide path and airspeed comprising the steps of: a. correcting for vertical displacements from the glide path by controlling the thrust level of the aircraft to vary the flight path angle of the aircraft, b. simultaneously controlling the pitch of the aircraft to maintain a desired angle of attack, said correcting step further comprising: c. determining the rate of which said aircraft is being displaced from said glide path and controlling the thrust level to reduce this rate to zero, and d. determining the linear displacement of said aircraft from said glide path and controlling the thrust level to return the aircraft to the glide path.
Claim 2
Independent Claim
122 words
The method of controlling an aircraft in an approach mode with respect to maintaining a desired glide path and airspeed comprising the steps of: a. correcting for vertical displacements from the glide path by controlling the thrust level of the aircraft to vary the flight path angle of the aircraft, b. simultaneously controlling the pitch of the aircraft to maintain a desired angle of attack, said correcting step further comprising: c. determining the rate of which said aircraft is being displaced from said glide path and controlling the thrust level to reduce this rate to zero, and d. determining the linear displacement of said aircraft from said glide path and controlling the thrust level to return the aircraft to the glide path.
Claim 3
Dependent Claim
82 words
The method of claim 1 wherein said step for controlling the pitch of said aircraft comprises: a. determining the rate at which the angle of attack of said aircraft is being displaced from said desired angle of attack and controlling the pitch of said aircraft to reduce this rate to zero, and b. determining the angular displacement of said aircraft from said desired angle of attack and controlling the pitch to return the angle of attack to the desired angle of attack.
Claim 4
Dependent Claim
48 words
The meThod of claim 2 further comprising: a. determining a desired rate of return to the desired angle of attack as a predetermined variable function of said angular displacement, and b. controlling the pitch to return the aircraft to said desired angle of attack at said desired rate.
Claim 5
Dependent Claim
45 words
The method of claim 1, wherein the magnitude of the thrust level control varies in a predetermined, but variable, manner relative to the magnitude of the aircraft''s vertical displacement from the glide path in order to produce a smooth return to a desired glide path.
Claim 6
Dependent Claim
58 words
The method of claim 1 wherein the magnitude of the pitch control varies in a predetermined, but variable, manner relative to the magnitude of the difference between the aircraft''s actual angle of attack and its desired angle of attack in order to produce a smooth controllable return to a desired angle of attack without producing overcorrections or oscillations.
Claim 7
Dependent Claim
58 words
The method of claim 1 wherein the magnitude of the thrust level control varies in a predetermined, but variable, manner relative to the magnitude of the difference between the actual rate of return to said glide path and the desired rate of return to said glide path in order to produce a smooth return to said glide path.
Claim 8
Dependent Claim
68 words
The method of claim 1 wherein the magnitude of the pitch control varies in a predetermined, but variable, manner relative to the magnitude of the difference between the aircraft''s actual rate of change of the angle of attack and the desired rate of change of the angle of attack in order to produce a smooth controllable return to said desired angle of attack without producing overcorrections or oscillations.
Claim 9
Dependent Claim
47 words
The method of claim 1 wherein said correcting step further comprises: a. determining a desired rate of return to said glide path as a function of said linear displacement, and b. controlling the thrust level to return the aircraft to said glide path at said desired rate.
Claim 10
Dependent Claim
117 words
An aircraft control system for automatically maintaining a desired glide path and a desired angle of attack during the approach mode of the aircraft, and having means to control the pitch level of said aircraft, wherein, said means for controlling said pitch level comprises: a. computing means for determining the angular displacement of said aircraft from said desired angle of attack, and b. computing means for determining the rate at which said aircraft is being angularly displaced from said desired angle of attack, whereby, said aircraft''s angular rate of displacement from said desired angle of attack is first reduced to zero and said aircraft''s angular displacement from said desired angle of attack is secondly reduced to zero.
Claim 11
Dependent Claim
117 words
An aircraft control system for automatically maintaining a desired glide path and a desired angle of attack during the approach mode of the aircraft, and having means to control the pitch level of said aircraft, wherein, said means for controlling said pitch level comprises: a. computing means for determining the angular displacement of said aircraft from said desired angle of attack, and b. computing means for determining the rate at which said aircraft is being angularly displaced from said desired angle of attack, whereby, said aircraft''s angular rate of displacement from said desired angle of attack is first reduced to zero and said aircraft''s angular displacement from said desired angle of attack is secondly reduced to zero.
Claim 12
Dependent Claim
102 words
An aircraft control system for maintaining a desired glide path and airspeed during the approach mode of the aircraft, and having means to control the thrust level of said aircraft, wherein said means for controlling said thrust level comprises: a. computing means for determining the linear displacement of said aircraft from said glide path, and b. computing means for determining the rate at which said aircraft is being displaced from said glide path, whereby said aircraft''s rate of displacement from said glide path is first reduced to zero and said aircraft''s linear displacement from said glide path is then reduced to zero.
Claim 13
Dependent Claim
102 words
An aircraft control system for maintaining a desired glide path and airspeed during the approach mode of the aircraft, and having means to control the thrust level of said aircraft, wherein said means for controlling said thrust level comprises: a. computing means for determining the linear displacement of said aircraft from said glide path, and b. computing means for determining the rate at which said aircraft is being displaced from said glide path, whereby said aircraft''s rate of displacement from said glide path is first reduced to zero and said aircraft''s linear displacement from said glide path is then reduced to zero.
Claim 14
Dependent Claim
97 words
In an aircraft control system the method of producing a correction signal for correcting a displacement of an aircraft to a desired value comprising the steps of: a. determining the magnitude of the displacement of the aircraft from the desired value; b. determining the desired rate of return to said desired value in proportion to the magnitude of said displacement; c. determining the actual rate of return to said desired value; and d. determining the difference between said desired rate of return and said actual rate of return to produce a correction signal proportional to said difference.
Claim 15
Dependent Claim
97 words
In an aircraft control system the method of producing a correction signal for correcting a displacement of an aircraft to a desired value comprising the steps of: a. determining the magnitude of the displacement of the aircraft from the desired value; b. determining the desired rate of return to said desired value in proportion to the magnitude of said displacement; c. determining the actual rate of return to said desired value; and d. determining the difference between said desired rate of return and said actual rate of return to produce a correction signal proportional to said difference.
Claim 16
Dependent Claim
40 words
The method as defined in claiM 11 wherein said desired value is a desired angle of attack of said aircraft during an approach mode, and said displacement is the angular displacement of said aircraft from said desired angle of attack.
Claim 17
Dependent Claim
38 words
The method as defined in claim 11 wherein said desired value is a desired glide path of said aircraft during an approach mode, and said displacement is the linear displacement of said aircraft from said desired glide path.
Claim 18
Dependent Claim
109 words
An aircraft control system for producing a correction signal for correcting a displacement of an aircraft to a desired value comprising: a. means for determining the magnitude of the displacement of the aircraft from the desired value; b. means for determining the desired rate of return to said desired value in proportion to the magnitude of said displacement; c. means for determining the actual rate of return to said desired value, d. means for determining the difference between said desired rate of return and said actual rate of return to produce a correction signal proportional to said difference and means responsive to said correction signal to control said aircraft.
Claim 19
Dependent Claim
109 words
An aircraft control system for producing a correction signal for correcting a displacement of an aircraft to a desired value comprising: a. means for determining the magnitude of the displacement of the aircraft from the desired value; b. means for determining the desired rate of return to said desired value in proportion to the magnitude of said displacement; c. means for determining the actual rate of return to said desired value, d. means for determining the difference between said desired rate of return and said actual rate of return to produce a correction signal proportional to said difference and means responsive to said correction signal to control said aircraft.
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) | 1974-06-21 | 1974-12-21 | 1975-06-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-06-21 | 1978-12-21 | 1979-06-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-06-21 | 1982-12-21 | 1983-06-22 | $7700.00 | Window Closed / Lapsed |