US3873050A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Attitude sensing method and apparatus
Assignee: Johns Hopkins University
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Filing: 1973-10-29
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Granted: 1975-03-25
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Expires: 1993-10-29
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 static voltmeter having a single voltage sensing probe which is referenced to a ground connection for determining the difference in voltage between the probe and ''''ground'''' in an object, such as an aircraft, carrying the probe. The probe senses the static voltage in the vertically-oriented electrostatic gradient in the earth''s atmosphere, this sensed voltage being compared to the potential at the ground connection to indicate the orientation of the probe relative to ground. A change in vertical orientation of the probe relative to the ground connection produces a voltage signal which is proportional to the magnitude of the difference in vertical orientation between the probe and the ground connection, this signal being utilizable in a known fashion to stabilize the aircraft or other object relative to the earth''s surface.
Inventors
- 👤 Maynard L Hill
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 05:34
CPC Classifications
G; G05; G05D; G05D1/00; G05D1/08; G05D1/0808
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
111 words
Apparatus for detecting the attitude 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 said electrostatic field; ground connection means on said vehicle; referencing means electrically connected to the probe means and the ground connection means for comparing the response to the electrostatic field sensed by said probe means to the potential existing at said ground connection means, said referencing means producing an output signal proportional thereto, said output signal indicating alignment between a reference line taken between said probe means and said ground connection means and an equipotential line existing in said earth''s electrostatic field.
Claim 2
Dependent Claim
111 words
Apparatus for detecting the attitude 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 said electrostatic field; ground connection means on said vehicle; referencing means electrically connected to the probe means and the ground connection means for comparing the response to the electrostatic field sensed by said probe means to the potential existing at said ground connection means, said referencing means producing an output signal proportional thereto, said output signal indicating alignment between a reference line taken between said probe means and said ground connection means and an equipotential line existing in said earth''s electrostatic field.
Claim 3
Dependent Claim
36 words
The apparatus of claim 1 and further comprising: stabilizing means on said vehicle responsive to said output signal for adjusting the attitude of said vehicle to cause said reference line to align with said equipotential line.
Claim 4
Dependent Claim
15 words
The apparatus of claim 1 wherein said probe means comprises an electrostatic voltage sensing probe.
Claim 5
Dependent Claim
18 words
The apparatus of claim 1 wherein the probe means is located along the longitudinal axis of the vehicle.
Claim 6
Dependent Claim
17 words
The apparatus of claim 1 wherein the probe is located along a transverse axis of the vehicle.
Claim 7
Dependent Claim
12 words
The apparatus of claim 1 wherein the referencing means is a voltmeter.
Claim 8
Dependent Claim
13 words
The apparatus of claim 1 wherein the referencing means is a current meter.
Claim 9
Dependent Claim
17 words
The apparatus of claim 7 wherein the probe means comprises a flat plate of electrically conductive material.
Claim 10
Dependent Claim
150 words
The apparatus of claim 1 wherein said probe means comprises a pair of static voltage sensing probes disposed on the airborne vehicle, a first probe and the ground connection means being disposed along a line substantially parallel to the roll axis of the vehicle and a second probe and the ground connection means being disposed along a line substantially parallel to the pitch axis of the vehicle, and wherein said referencing means comprises two voltmeters, one of said voltmeters being electrically connected to the first probe and the other of said voltmeters being electrically connected to the second probe, each said voltmeter receiving the potentials sensed by the probes, and comparing said sensed potentials to the potential existing at said ground connection means, each voltmeter further producing an output signal which is proportional to the respective difference in sensed potential between each of the probes and said ground connection means.
Claim 11
Dependent Claim
56 words
The apparatus of claim 9 and further comprising: means for adjusting the position of each of the probes to cause the output signal of the voltmeters 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 voltmeters are zero.
Claim 12
Independent Claim
106 words
A method for detecting the attitude of an airborne vehicle operating in the electric field existing in the earth''s atmosphere, comprising the steps of: sensing the potential of said electrostatic field with probe means responsive to the electrostatic field; measuring the potential at a ground connection on the vehicle; comparing the potential sensed by said probe means with the potential measured at said ground connection; and generating an output signal proportional to the difference in the two potentials, said output signal indicating alignment between a reference line taken between said probe means and said ground connection and an equipotential line existing in said earth''s electrostatic field.
Claim 13
Independent Claim
106 words
A method for detecting the attitude of an airborne vehicle operating in the electric field existing in the earth''s atmosphere, comprising the steps of: sensing the potential of said electrostatic field with probe means responsive to the electrostatic field; measuring the potential at a ground connection on the vehicle; comparing the potential sensed by said probe means with the potential measured at said ground connection; and generating an output signal proportional to the difference in the two potentials, said output signal indicating alignment between a reference line taken between said probe means and said ground connection and an equipotential line existing in said earth''s electrostatic field.
Claim 14
Dependent Claim
29 words
The method of claim 11 and further comprising the step of: adjusting the attitude of said vehicle to cause said reference line to align with the aforesaid equipotential line.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-24 | 1978-09-23 | 1979-03-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-24 | 1982-09-23 | 1983-03-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-24 | 1986-09-23 | 1987-03-25 | $7700.00 | Window Closed / Lapsed |