US3868074A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for attitude detection and stabilization of an airborne vehicle using the electrostatic field in the earth{3 s atmosphere
Assignee: Johns Hopkins University
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Filing: 1972-10-27
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Granted: 1975-02-25
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Expires: 1992-10-27
Abstract
Abstract A method and apparatus for utilizing the earth''s static electric field as a reference for generating an information-bearing electrical signal. In a particular embodiment, the invention provides a differential static voltmeter having spaced voltage sensing probes and a differential static amplifier which determines the difference in voltage sensed by the probes. Since the probes measure the static voltage which occurs as a vertically oriented gradient in the earth''s atmosphere, the voltage difference signal produced by the differential static amplifier is a measure of the disposition of the probes relative to a line usually parallel to the earth''s surface, the voltmeter thereby being particularly useful as a pitch and roll stabilization reference and control system for airborne vehicles. In other embodiments, the invention also provides apparatus for defining a horizontal reference plane in the atmosphere and apparatus for sensing the roll or pitch rate of an airborne vehicle.
Inventors
- 👤 Maynard L Hill
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 15:37
CPC Classifications
G; G01; G01R; G01R29/00; G01R29/12; G01C; G01C9/00; G01C9/18; G01P; G01P3/00; G01P3/42; G01P3/50; G01P3/52
Claims Analysis
Total Claims: 51
Claim 1
Independent Claim
133 words
A method for stabilization relative to the surface of the earth of at least one axis of an airborne vehicle operating in the static electric field existing in the earth''s atmosphere, comprising the steps of: sensing the electrostatic potential at each of two spaced points disposed substantially along a line extending in the same direction as the axis about which the vehicle is to be stabilized; generating a potential difference signal proportional to the magnitude of the difference in the two sensed potentials, the magnitude of the signal being proportional to the angular misalignment of the aforesaid axis and an equipotential line intersecting said axis; and, angularly displacing the position of the axis of the vehicle to align with the aforesaid equipotential line in response to the magnitude of the potential difference signal.
Claim 2
Independent Claim
133 words
A method for stabilization relative to the surface of the earth of at least one axis of an airborne vehicle operating in the static electric field existing in the earth''s atmosphere, comprising the steps of: sensing the electrostatic potential at each of two spaced points disposed substantially along a line extending in the same direction as the axis about which the vehicle is to be stabilized; generating a potential difference signal proportional to the magnitude of the difference in the two sensed potentials, the magnitude of the signal being proportional to the angular misalignment of the aforesaid axis and an equipotential line intersecting said axis; and, angularly displacing the position of the axis of the vehicle to align with the aforesaid equipotential line in response to the magnitude of the potential difference signal.
Claim 3
Dependent Claim
43 words
The method of claim 1 and further comprising the steps of: measuring the magnitude of the potential gradient existing in the static electric field; and, adjusting the gain of the potential difference signal in proportion to the magnitude of the measured potential gradient.
Claim 4
Independent Claim
206 words
A method for stabilization along the pitch and roll axes of an airborne vehicle operating in the static electric field existing in the earth''s atmosphere, comprising the steps of: sensing the electrostatic potential at each point of two non-linear pairs of spaced points disposed on the airborne vehicle, a first pair of points lying along a line extending in essentially the same direction as the longitudinal or pitch axis of the vehicle and a second pair of points lying along a line extending in essentially the same direction as the transverse or roll axis of the vehicle; generating a potential difference signal proportional to the magnitude of the difference in the potential sensed at each point in each pair of points, the magnitude of the difference signal generated between the points in the first pair of points being proportional to the pitch angle of the vehicle and the magnitude of the difference signal generated between the points in the second pair of points being proportional to the roll angle of the vehicle; and, angularly displacing both the pitch and roll axis of the vehicle to reduce the respective potential difference signals to zero, the displacements being responsive to the magnitude of the respective potential difference signals.
Claim 5
Independent Claim
206 words
A method for stabilization along the pitch and roll axes of an airborne vehicle operating in the static electric field existing in the earth''s atmosphere, comprising the steps of: sensing the electrostatic potential at each point of two non-linear pairs of spaced points disposed on the airborne vehicle, a first pair of points lying along a line extending in essentially the same direction as the longitudinal or pitch axis of the vehicle and a second pair of points lying along a line extending in essentially the same direction as the transverse or roll axis of the vehicle; generating a potential difference signal proportional to the magnitude of the difference in the potential sensed at each point in each pair of points, the magnitude of the difference signal generated between the points in the first pair of points being proportional to the pitch angle of the vehicle and the magnitude of the difference signal generated between the points in the second pair of points being proportional to the roll angle of the vehicle; and, angularly displacing both the pitch and roll axis of the vehicle to reduce the respective potential difference signals to zero, the displacements being responsive to the magnitude of the respective potential difference signals.
Claim 6
Dependent Claim
44 words
The method of claim 3 and further comprising the steps of: measuring the magnitude of the potential gradient existing in the static electric field; and, adjusting the gain of the respective potential difference signals in proportion to the magnitude of the measured potential gradient.
Claim 7
Independent Claim
55 words
A method for stabilization of at least one axis of an airborne vehicle operating in the static electric field eXisting in the earth''s atmosphere, comprising the steps of: defining an equipotential line existing in the static electric field present in the earth''s atmosphere; and, aligning the axis of the airborne vehicle with the equipotential line.
Claim 8
Independent Claim
55 words
A method for stabilization of at least one axis of an airborne vehicle operating in the static electric field eXisting in the earth''s atmosphere, comprising the steps of: defining an equipotential line existing in the static electric field present in the earth''s atmosphere; and, aligning the axis of the airborne vehicle with the equipotential line.
Claim 9
Independent Claim
59 words
A method for stabilization along the pitch and roll axes of an airborne vehicle operating in the static electric field existing in the earth''s atmosphere, comprising the steps of: defining an equipotential plane existing in the static electric field present in the earth''s atmosphere; and, aligning the pitch and the roll axes of the vehicle with the equipotential plane.
Claim 10
Independent Claim
59 words
A method for stabilization along the pitch and roll axes of an airborne vehicle operating in the static electric field existing in the earth''s atmosphere, comprising the steps of: defining an equipotential plane existing in the static electric field present in the earth''s atmosphere; and, aligning the pitch and the roll axes of the vehicle with the equipotential plane.
Claim 11
Independent Claim
199 words
A method for stabilization along the pitch and roll axes of an airborne vehicle operating in the static electric field existing in the earth''s atmosphere, comprising the steps of: sensing the electrostatic potential at each of at least three non-linear points disposed on the airborne vehicle; generating a potential difference signal proportional to the magnitude of the difference in potential between at least two of the points, the two points lying along a line extending in essentially the same direction as one of the axes of the vehicle, the magnitude of the difference signal being proportional to the angular misalignment of the said axis and an equipotential line intersecting said axis; angularly displacing the position of the aforesaid axis to align with the aforesaid equipotential line in response to the magnitude of the generated potential difference signal; generating a second potential difference signal proportional to the magnitude of the difference inpotential between a third point and the line joining the aforementioned two points; and, displacing the third point relative to the line joining the aforementioned two points to reduce the second potential difference signal to zero, the displacement being responsive to the magnitude of the second potential difference signal.
Claim 12
Independent Claim
199 words
A method for stabilization along the pitch and roll axes of an airborne vehicle operating in the static electric field existing in the earth''s atmosphere, comprising the steps of: sensing the electrostatic potential at each of at least three non-linear points disposed on the airborne vehicle; generating a potential difference signal proportional to the magnitude of the difference in potential between at least two of the points, the two points lying along a line extending in essentially the same direction as one of the axes of the vehicle, the magnitude of the difference signal being proportional to the angular misalignment of the said axis and an equipotential line intersecting said axis; angularly displacing the position of the aforesaid axis to align with the aforesaid equipotential line in response to the magnitude of the generated potential difference signal; generating a second potential difference signal proportional to the magnitude of the difference inpotential between a third point and the line joining the aforementioned two points; and, displacing the third point relative to the line joining the aforementioned two points to reduce the second potential difference signal to zero, the displacement being responsive to the magnitude of the second potential difference signal.
Claim 13
Independent Claim
110 words
A method for stabilization along at least one axis of an airborne vehicle operating in the static electric field existing in the earth''s atmosphere, comprising the steps of: disposing at least two electrically conductive members on the vehicle about an axis thereof, the members being electrically connected; generating a signal proportional to the current flowing between the conductive members on displacement of the vehicle about the axis, the magnitude of the current flow being proportional to the rate of angular displacement of the vehicle about the axis; and, damping the rate of angular displacement of the vehicle about the aforesaid axis to inhibit displacement of the vehicle about said axis.
Claim 14
Independent Claim
110 words
A method for stabilization along at least one axis of an airborne vehicle operating in the static electric field existing in the earth''s atmosphere, comprising the steps of: disposing at least two electrically conductive members on the vehicle about an axis thereof, the members being electrically connected; generating a signal proportional to the current flowing between the conductive members on displacement of the vehicle about the axis, the magnitude of the current flow being proportional to the rate of angular displacement of the vehicle about the axis; and, damping the rate of angular displacement of the vehicle about the aforesaid axis to inhibit displacement of the vehicle about said axis.
Claim 15
Dependent Claim
98 words
Apparatus for stabilization about at least one axis of an airborne vehicle operating in the electric field existing in the earth''s atmosphere, comprising: at least two static voltage sensing probes disposed on the airborne vehicle; means electrically connected to the probes for receiving the potentials sensed by said probes and for producing an output signal proportional to the difference in sensed potential between the probes; and, means for adjusting the position of at least one of the probes to cause the output signal to be zero, the line joining the probes thereby being aligned along an equipotential line.
Claim 16
Dependent Claim
98 words
Apparatus for stabilization about at least one axis of an airborne vehicle operating in the electric field existing in the earth''s atmosphere, comprising: at least two static voltage sensing probes disposed on the airborne vehicle; means electrically connected to the probes for receiving the potentials sensed by said probes and for producing an output signal proportional to the difference in sensed potential between the probes; and, means for adjusting the position of at least one of the probes to cause the output signal to be zero, the line joining the probes thereby being aligned along an equipotential line.
Claim 17
Dependent Claim
22 words
The apparatus of claim 9 wherein the probes are disposed along a line parallel to the roll axis of the airborne vehicle.
Claim 18
Dependent Claim
25 words
The apparatus of claim 9 wherein the probes are located along a line disposed at an angle to the roll axis of the airborne vehicle.
Claim 19
Dependent Claim
12 words
The apparatus of claim 11 wherein the angle is less than 45*.
Claim 20
Dependent Claim
22 words
The apparatus of claim 9 wherein the probes are disposed along a line parallel to the pitch axis of the airborne vehicle.
Claim 21
Dependent Claim
25 words
The apparatus of claim 9 wherein the probes are located along a line disposed at an angle to the pitch axis of the airborne vehicle.
Claim 22
Dependent Claim
12 words
The apparatus of claim 14 wherein the angle is less than 45*.
Claim 23
Dependent Claim
13 words
The apparatus of claim 9 wherein said first-mentioned means comprises a differential amplifier.
Claim 24
Dependent Claim
202 words
Apparatus for stabilization relative to the surface of the earth about the pitch and roll axes of an airborne vehicle operating in the static electric field existing in the earth''s atmosphere, comprising: two pairs of static voltage sensing probes disposed on the airborne vehicle, one said pair being disposed along a line substantially parallel to the roll axis of the vehicle and the other pair being disposed along a line substantially parallel to the pitch axis of the vehicle, the probes in each pair of probes being disposed at spaced, co-planar points on the vehicle; two differential amplifiers, one each being electrically connected to one pair of probes for receiving the potentials sensed by the probes of each pair of probes, each said amplifier producing an output signal which is proportional to the difference in sensed potential between the sensing probes of each pair of probes; and, means for adjusting the position of at least one of the probes in each pair of probes to cause the output signal of the amplifiers respectively connected thereto to be zero, the vehicle thus being stabilized relative to the equipotential plane in which the probes lie when the output signals of both amplifiers are zero.
Claim 25
Dependent Claim
202 words
Apparatus for stabilization relative to the surface of the earth about the pitch and roll axes of an airborne vehicle operating in the static electric field existing in the earth''s atmosphere, comprising: two pairs of static voltage sensing probes disposed on the airborne vehicle, one said pair being disposed along a line substantially parallel to the roll axis of the vehicle and the other pair being disposed along a line substantially parallel to the pitch axis of the vehicle, the probes in each pair of probes being disposed at spaced, co-planar points on the vehicle; two differential amplifiers, one each being electrically connected to one pair of probes for receiving the potentials sensed by the probes of each pair of probes, each said amplifier producing an output signal which is proportional to the difference in sensed potential between the sensing probes of each pair of probes; and, means for adjusting the position of at least one of the probes in each pair of probes to cause the output signal of the amplifiers respectively connected thereto to be zero, the vehicle thus being stabilized relative to the equipotential plane in which the probes lie when the output signals of both amplifiers are zero.
Claim 26
Dependent Claim
112 words
The apparatus of claim 17 and further comprising: a pair of vertically disposed static voltage sensing probes, one probe of the pair being disposed above the plane containing the four aforementioned probes and the other probe being disposed below the aforesaid plane; means for receiving the potentials sensed by the vertically disposed probes and for producing an output signal proportional to the static voltage gradient between the probes; and, gain control adjustment means responsive to the last-mentioned output signal to provide automatic control of the gain required to render the first-mentioned output signals of sufficient magnitude to actuate the means for adjusting the position of the probes in each pair of probes.
Claim 27
Dependent Claim
119 words
Apparatus for detecting the attitude relative to the surface of the earth of an airborne vehicle operating in the electrostatic field existing in the earth''s atmosphere, comprising: probe means mounted on said vehicle and responsive to the magnitude of said electrostatic field at a first preselected point relative to a second preselected point, said first and second preselected points being spaced apart and defining a reference line on said vehicle; and, means connected to said probe means for producing an output signal proportional to the difference in relative magnitude of said electrostatic field at said first and second preselected points, said output signal indicating misalignment between said reference line and an equipotential line existing in said earth''s electrostatic field.
Claim 28
Dependent Claim
119 words
Apparatus for detecting the attitude relative to the surface of the earth of an airborne vehicle operating in the electrostatic field existing in the earth''s atmosphere, comprising: probe means mounted on said vehicle and responsive to the magnitude of said electrostatic field at a first preselected point relative to a second preselected point, said first and second preselected points being spaced apart and defining a reference line on said vehicle; and, means connected to said probe means for producing an output signal proportional to the difference in relative magnitude of said electrostatic field at said first and second preselected points, said output signal indicating misalignment between said reference line and an equipotential line existing in said earth''s electrostatic field.
Claim 29
Dependent Claim
45 words
The apparatus of claim 19 further including stabilizing means on said vehicle responsive to said output signal for adjusting the attitude of said vehicle to cause said output signal to be zero and thereby align the reference line on said vehicle with said equipotential line.
Claim 30
Dependent Claim
195 words
The apparatus specified in claim 20, wherein said probe means comprises two pairs of static voltage sensing probes disposed on the airborne vehicle, one said pair being disposed along a line substantially parallel to the roll axis of the vehicle and the other pair being disposed along a line substantially parallel to the pitch axis of the vehicle, the probes in each pair of probes being disposed at spaced, substantially horizontal co-planar points on the vehicle; wherein said output signal producing means comprises two differential amplifiers, one each being electrically connected to one pair of probes for receiving the potentials sensed by the probes of each pair of probes, each said amplifier producing an output signal which is proportional to the difference in sensed potential between the sensing proBes of each pair of probes; and, wherein said stabilizing means comprises means for adjusting the position of at least one of the probes in each pair of probes to cause the output signal of the amplifiers respectively connected thereto to be zero, the vehicle thus being stabilized relative to the equipotential plane in which the probes lie when the output signals of both amplifiers are zero.
Claim 31
Dependent Claim
124 words
The apparatus of claim 21 and further comprising: a pair of vertically disposed voltage sensing probes, one probe of the pair being disposed above the substantially horizontal plane containing the four aforementioned probes and the other probe being disposed below the aforesaid substantially horizontal plane; means for receiving the potentials sensed by the vertically disposed probes and for producing an output signal proportional to the static voltage gradient between the probes; and, gain control adjustment means responsive to the output signal proportional to said static voltage gradient to provide automatic control of the gain required to render the output signals produced by said differential amplifiers of sufficient magnitude to actuate the means for adjusting the position of the probes in each pair of probes.
Claim 32
Dependent Claim
32 words
The apparatus specified in claim 19 wherein said probe means comprises at least first and second electrostatic voltage sensor probes mounted on said vehicle at said first and second preselected points respectively.
Claim 33
Dependent Claim
22 words
The apparatus of claim 23 wherein the probes are disposed along a line parallel to the roll axis of the airborne vehicle.
Claim 34
Dependent Claim
25 words
The apparatus of claim 23 wherein the probes are located along a line disposed at an angle to the roll axis of the airborne vehicle.
Claim 35
Dependent Claim
12 words
The apparatus of claim 25 wherein the angle is less than 45*.
Claim 36
Dependent Claim
22 words
The apparatus of claim 23 wherein the probes are disposed along a line parallel to the pitch axis of the airborne vehicle.
Claim 37
Dependent Claim
25 words
The apparatus of claim 23 wherein the probes are located along a line disposed at an angle to the pitch axis of the airborne vehicle.
Claim 38
Dependent Claim
12 words
The apparatus of claim 28 wherein the angle is less than 45*.
Claim 39
Dependent Claim
16 words
The apparatus specified in claim 19 wherein said output signal producing means comprises a differential amplifier.
Claim 40
Independent Claim
93 words
A method for detecting the attitude relative to the surface of the earth of at least one axis of an airborne vehicle in the static electric field existing in the earth''s atmosphere, comprising the steps of: defining an equipotential line in the electrostatic field existing in the earth''s atmosphere, which line is substantially parallel to the surface of the earth; and, generating a signal indicative of misalignment between the axis of said vehicle and said equipotential line, and thus the misalignment between the axis of the vehicle and the surface of the earth.
Claim 41
Independent Claim
93 words
A method for detecting the attitude relative to the surface of the earth of at least one axis of an airborne vehicle in the static electric field existing in the earth''s atmosphere, comprising the steps of: defining an equipotential line in the electrostatic field existing in the earth''s atmosphere, which line is substantially parallel to the surface of the earth; and, generating a signal indicative of misalignment between the axis of said vehicle and said equipotential line, and thus the misalignment between the axis of the vehicle and the surface of the earth.
Claim 42
Dependent Claim
23 words
The method specified in claim 31 and further including the step of aligning said axis of said airborne vehicle with said equipotential line.
Claim 43
Dependent Claim
46 words
The method specified in claim 31 and further including the steps of: defining a second equipotential line existing in the electrostatic field to define an equipotential plane existing in said electrostatic field; and, aligning the pitch and roll axes of the vehicle with said equipotential plane.
Claim 44
Dependent Claim
42 words
The method specified in claim 31 wherein the step of defining said equipotential line includes the step of: sensing said electrostatic field with probe means responsive to the relative magnitude of the electro-static field at two spaced points defining said vehicle axis.
Claim 45
Dependent Claim
107 words
The method specified in claim 34, wherein the step of sensing the relative magnitude of said electrostatic field comprises the step of sensing the electrostatic potential at each of two spaced points disposed along a substantially horizontal line extending in the same direction as the axis about which the vehicle is to be stabilized; and, wherein the step of generating said misalignment indicatiNg signal comprising the step of generating a potential difference signal proportional to the magnitude of the difference in the two sensed potentials, the magnitude of the signal being proportional to the angular misalignment of the aforesaid axis and an equipotential line intersecting said axis.
Claim 46
Dependent Claim
47 words
The method as specified in claim 35 and further comprising the steps of: measuring the magnitude of the vertical potential gradient existing in the static electric field; and, adjusting the gain of the potential difference signal in proportion to the magnitude of the measured vertical potential gradient.
Claim 47
Dependent Claim
73 words
The method as specified in claim 34, and further comprising the steps of: disposing at least two electrically conductive members on the vehicle about the axis thereof, the members being electrically connected; and, generating a signal proportional to the current flowing between the conductive members on displacement of the vehicle about the axis, the magnitude of the current flow being proportional to the rate of angular displacement of the vehicle about the axis.
Claim 48
Independent Claim
119 words
A method for detecting the attitude relative to the surface of the earth of at least one axis of an airborne vehicle operating in the static electric field existing in the earth''s atmosphere, comprising the steps of: sensing the electrostatic potential at a first point in the atmosphere; locating a second point in the atmosphere having the same electrostatic potential as the first point to define an equipotential line in the static electric field, the equipotential line being substantially parallel to the surface of the earth; and, generating a signal indicative of misalignment between the axis of the vehicle and the equipotential line, and thus the misalignment between the axis of the vehicle and the surface of the earth.
Claim 49
Independent Claim
119 words
A method for detecting the attitude relative to the surface of the earth of at least one axis of an airborne vehicle operating in the static electric field existing in the earth''s atmosphere, comprising the steps of: sensing the electrostatic potential at a first point in the atmosphere; locating a second point in the atmosphere having the same electrostatic potential as the first point to define an equipotential line in the static electric field, the equipotential line being substantially parallel to the surface of the earth; and, generating a signal indicative of misalignment between the axis of the vehicle and the equipotential line, and thus the misalignment between the axis of the vehicle and the surface of the earth.
Claim 50
Dependent Claim
31 words
The method of claim 38 wherein the two points are disposed substantially along the line extending in the same direction as the axis about which the vehicle is to be stabilized.
Claim 51
Dependent Claim
30 words
The method of claim 38 and further comprising the step of: aligning the axis of the airborne vehicle in response to the generated signal with the equipotential line thus defined.
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USPTO Annuity & Maintenance Windows
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|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-02-24 | 1978-08-26 | 1979-02-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-24 | 1982-08-26 | 1983-02-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-24 | 1986-08-26 | 1987-02-25 | $7700.00 | Window Closed / Lapsed |