Patent US3793890A successfully refreshed from Google Patents.
US3793890A
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Digital electronic integrating accelerometer
Assignee: United States Department of the Navy
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Filing: 1972-05-22
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Granted: 1974-02-26
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Expires: 1992-05-22
Abstract
Abstract An acceleration signal is integrated over a determinable time period to develop a digital count which is a function of velocity; that signal is then again integrated over an identical time period to produce a digital count as a function of the distance traveled during the acceleration periods. The distance signal is compared to a reference signal to determine whether a missile, for example, undergoing the detected acceleration has traveled a sufficient distance from its launching site,or vehicle such as an aircraft, to be safely armed for detonation. A digital distance signal equal to the reference signal affects arming of the missile by aligning an explosive train, for example, for detonation. First and second interlocks in the system are responsive to a ready-to-launch signal and an initial minimum acceleration signal, respectively, to ready the system for arming. The final step of arming is accomplished by a cam driven into arming position by simultaneously actuated drive members which are pivotably attached to the arming cam. If only one of the two drive members is actuated by a spurious signal, for example, the cam is pivotably displaced and locked into a nonarmed position.
Inventors
- 👤 M Anderson
- 👤 S Redmond
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 13:06
CPC Classifications
F; F42; F42C; F42C15/00; F42C15/40; G; G01; G01P; G01P15/00; G01P15/02; G01P15/08; G01P15/12; G01P15/121; G01P7/00
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
167 words
An apparatus for producing a digital output representation of velocity in response to an acceleration signal developed during a determinable fixed time period comprising: an up-down binary counter; a source of constant frequency signals connected as an input to said counter; a signal source producing first and second alternate states normally of equal duration within repetitive cycles of said determinable fixed time period, and being connected to said binary counter for causing an up count of said constant frequency signals during one of said states and a down count curing the other of said states; an accelerometer for producing an electrical signal as a function of its instantaneous acceleration; said electrical signal being connected to said signal source for producing changes of opposite sense in the respective duration of said first and second states without changing said determinable fixed time period; whereby the net count accumulated by said counter is the time integral of acceleration during each said determinable fixed time period, and is representative of velocity.
Claim 2
Independent Claim
167 words
An apparatus for producing a digital output representation of velocity in response to an acceleration signal developed during a determinable fixed time period comprising: an up-down binary counter; a source of constant frequency signals connected as an input to said counter; a signal source producing first and second alternate states normally of equal duration within repetitive cycles of said determinable fixed time period, and being connected to said binary counter for causing an up count of said constant frequency signals during one of said states and a down count curing the other of said states; an accelerometer for producing an electrical signal as a function of its instantaneous acceleration; said electrical signal being connected to said signal source for producing changes of opposite sense in the respective duration of said first and second states without changing said determinable fixed time period; whereby the net count accumulated by said counter is the time integral of acceleration during each said determinable fixed time period, and is representative of velocity.
Claim 3
Dependent Claim
61 words
An apparatus for producing a digital output representative of distance in response to an acceleration signal developed during a determinable fixed time period, including the apparatus as claimed in claim 1 and further comprIsing: means for integrating said net count over an additional time period for producing an output signal as a function of the distance traveled during said time periods.
Claim 4
Dependent Claim
29 words
An apparatus for producing a digital output representative of velocity as claimed in claim 1 wherein said signal source producing first and second states is a square wave generator.
Claim 5
Dependent Claim
38 words
An apparatus for producing a digital output representative of velocity as claimed in claim 3 wherein said square wave generator is a free-running multivibrator having two symmetrically identical stages of electrical elements including a commonly connected resistive element.
Claim 6
Dependent Claim
39 words
An apparatus for producing a digital output representative of velocity as claimed in claim 4 wherein said accelerometer displaces a variable tap on said commonly connected resistive element to produce said electrical signal as a function of instantaneous acceleration.
Claim 7
Independent Claim
132 words
A method for providing a digital count representative of the time integral of acceleration over a determinable fixed time increment comprising the steps of: generating electrical signals alternating between first and second states within a constant cyclic period equal to the determinable fixed time increment and having a cross-over between the two states normally at the mid-point of each cyclic period; causing time displacement of the cross-over within the constant cyclic period responsive to a detected acceleration; applying constant frequency signals of higher frequency to a digital counter capable of counting additively and subtractively; and, controlling the additive count in the digital counter in response to the first state of the electrical signals, and controlling the subtractive count in the digital counter in response to the second state of the electrical signal.
Claim 8
Independent Claim
132 words
A method for providing a digital count representative of the time integral of acceleration over a determinable fixed time increment comprising the steps of: generating electrical signals alternating between first and second states within a constant cyclic period equal to the determinable fixed time increment and having a cross-over between the two states normally at the mid-point of each cyclic period; causing time displacement of the cross-over within the constant cyclic period responsive to a detected acceleration; applying constant frequency signals of higher frequency to a digital counter capable of counting additively and subtractively; and, controlling the additive count in the digital counter in response to the first state of the electrical signals, and controlling the subtractive count in the digital counter in response to the second state of the electrical signal.
Claim 9
Dependent Claim
29 words
A method as claimed in claim 6 wherein the electrical signals alternating between first and second states within a constant cyclic period are in the form of square waves.
Claim 10
Dependent Claim
23 words
A method as claimed in claim 7 wherein the square waves are formed by alternate states of positive potential and substantially zero potential.
Claim 11
Dependent Claim
20 words
A method as claimed in claim 6 including the further step of resetting the digital counter after each cyclic period.
Claim 12
Dependent Claim
35 words
A method as claimed in claim 6 including the further step of averaging the digital count for two successive time increments to produce a digital count representative of average velocity over the second time increment.
Claim 13
Dependent Claim
44 words
A method as claimed in claim 6 including the further step of integrating the digital count representative of the time integral of acceleration over an additional identical time increment to provide a digital count representative of the distance traveled during the period of acceleration.
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) | 1977-02-25 | 1977-08-27 | 1978-02-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-25 | 1981-08-27 | 1982-02-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-25 | 1985-08-27 | 1986-02-26 | $7700.00 | Window Closed / Lapsed |