US3878724A
Expired / Lapsed
US
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Physically realizable optimum predictor filter technique for transducers, sensors, and other massive devices, based upon inverse transfers function synthesis
Assignee: Individual
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Filing: 1972-11-16
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Granted: 1975-04-22
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Expires: 1992-11-16
Abstract
Abstract Extending the application of transfer function cancellation or compensation via a separate filter to the sensormedia regime itself; with the objective of cancelling out sensor response time lags. This is achieved by first analyzing the transfer function of the sensor-media combination of interest, then synthesizing a filter that essentially cancels out that transfer function. Prior filter (electronic, mechanical, etc.) art has presumed the output of a sensor or transducer to be the reference input for all practical purposes of analysis and synthesis. To rapidly and practically derive this transfer function, the inventor has developed a graphical technique that directly extracts exponential terms from time-response data plotted on semilogarithmic graph paper, thereby directly yielding terms of the corresponding transfer function; i.e., Laplace transform of response as a function of time. The effective cancellation of heretofore-accepted sensor response-time limitations, makes possible drastic reductions in measurement and system response times, where these response times are primarily limited by the mechanical, electronic, acoustic, thermodynamic, or particle limitations of the sensors or transducers employed.
Inventors
- 👤 Gerald F Allen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 18:47
CPC Classifications
G; G01; G01K; G01K7/00; G01K7/42; G01K13/00; G01K13/20
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
112 words
A method of reducing the response time of a sensor positioned in a medium under observation comprising the steps of: a. placing the sensor in the medium under observation, b. feeding output signals from the sensor to filter means having a transfer function equal to the reciprocal of the sensor/medium characteristic function, said sensor/medium characteristic function corresponding to a sensor/medium response function f(t) represented by a sum of at least two exponential terms, each term having the form ae Mt, where a and M are constants and t is the time parameter, c. modulating said signals by said filter means, and d. feeding output signals from said filter means to indication means.
Claim 2
Independent Claim
112 words
A method of reducing the response time of a sensor positioned in a medium under observation comprising the steps of: a. placing the sensor in the medium under observation, b. feeding output signals from the sensor to filter means having a transfer function equal to the reciprocal of the sensor/medium characteristic function, said sensor/medium characteristic function corresponding to a sensor/medium response function f(t) represented by a sum of at least two exponential terms, each term having the form ae Mt, where a and M are constants and t is the time parameter, c. modulating said signals by said filter means, and d. feeding output signals from said filter means to indication means.
Claim 3
Independent Claim
112 words
A method of reducing the response time of a sensor positioned in a medium under observation comprising the steps of: a. placing the sensor in the medium under observation, b. feeding output signals from the sensor to filter means having a transfer function equal to the reciprocal of the sensor/medium characteristic function, said sensor/medium characteristic function corresponding to a sensor/medium response function f(t) represented by a sum of at least two exponential terms, each term having the form ae Mt, where a and M are constants and t is the time parameter, c. modulating said signals by said filter means, and d. feeding output signals from said filter means to indication means.
Claim 4
Independent Claim
112 words
A method of reducing the response time of a sensor positioned in a medium under observation comprising the steps of: a. placing the sensor in the medium under observation, b. feeding output signals from the sensor to filter means having a transfer function equal to the reciprocal of the sensor/medium characteristic function, said sensor/medium characteristic function corresponding to a sensor/medium response function f(t) represented by a sum of at least two exponential terms, each term having the form ae Mt, where a and M are constants and t is the time parameter, c. modulating said signals by said filter means, and d. feeding output signals from said filter means to indication means.
Claim 5
Dependent Claim
18 words
A method of reducing response times as recited in claim 1 wherein said sensor comprises temperature transducer means.
Claim 6
Dependent Claim
47 words
A method of reducing response times as recited in claim 1 further comprising the steps of: rapidly positioning said sensor in the medium, and determining said filter transfer function by the steps of: measuring the sensor/medium response function, approximating said sensor/medium response function f(t) by the relation
Claim 7
Dependent Claim
18 words
A method of minimizing response time as recited in claim 3 wherein said sensor comprises temperature transducer means.
Claim 8
Independent Claim
125 words
A method of reducing the response time of a sensor positioned in a medium under observation comprising the steps of: a. rapidly positioning the sensor in the medium under observation, b. feeding output signals from the sensor to filter means having a transfer function equal to the reciprocal of the sensor/medium characteristic function, said sensor/medium characteristic function corresponding to a sensor/medium response function f(t) substantially approximated by a sum of two exponentials having the form f(t) A1 e M t + A2 e M t where f(t) o at t O and A1 , M1 , A2 , M2 are constants and t is the time parameter, modulating said signals by said filter means and feeding output signals from said filter means to indication means.
Claim 9
Independent Claim
125 words
A method of reducing the response time of a sensor positioned in a medium under observation comprising the steps of: a. rapidly positioning the sensor in the medium under observation, b. feeding output signals from the sensor to filter means having a transfer function equal to the reciprocal of the sensor/medium characteristic function, said sensor/medium characteristic function corresponding to a sensor/medium response function f(t) substantially approximated by a sum of two exponentials having the form f(t) A1 e M t + A2 e M t where f(t) o at t O and A1 , M1 , A2 , M2 are constants and t is the time parameter, modulating said signals by said filter means and feeding output signals from said filter means to indication means.
Claim 10
Dependent Claim
122 words
Apparatus for sensing a basic excitation provided by a medium under observation comprising: sensor means having an input responsive to the basic excitation of the medium, said sensor means having an output, said sensor output providing output signals having a sensor/medium response function approximately represented by a sum of at least two exponential terms, compensating filter means connected to receive said sensor output signals, said compensating filter means having A transfer function equal to the reciprocal of the sensor/medium characteristic function G(s), said sensor/medium response function f(t) substantially approximated by a sum of at least two exponential terms of the form Ae t/T, where T and A are constants, and s is the Laplace complex variable and t is the time parameter.
Claim 11
Dependent Claim
122 words
Apparatus for sensing a basic excitation provided by a medium under observation comprising: sensor means having an input responsive to the basic excitation of the medium, said sensor means having an output, said sensor output providing output signals having a sensor/medium response function approximately represented by a sum of at least two exponential terms, compensating filter means connected to receive said sensor output signals, said compensating filter means having A transfer function equal to the reciprocal of the sensor/medium characteristic function G(s), said sensor/medium response function f(t) substantially approximated by a sum of at least two exponential terms of the form Ae t/T, where T and A are constants, and s is the Laplace complex variable and t is the time parameter.
Claim 12
Dependent Claim
14 words
Apparatus as defined in claim 6, wherein said sensor means comprises temperature transducer means.
Claim 13
Dependent Claim
16 words
Apparatus as defined in claim 6, wherein said compensating filter means comprises electrical filter circuit means.
Claim 14
Dependent Claim
28 words
Apparatus as defined in claim 6, wherein said sensor means comprises a thermometer probe having electrical transducer means therein, and said compensating filter means comprises electrical filter means.
Claim 15
Dependent Claim
13 words
Apparatus as defined in claim 9, wherein said transducer means comprises a thermistor.
Claim 16
Dependent Claim
17 words
Apparatus as defined in claim 9, which includes a disposable resilient sheath releasably engaged over said probe.
Claim 17
Dependent Claim
28 words
Apparatus as recited in claim 6 wherein said sensor/medium response function is approximately by f(t) A1e t/T + A2e t/T and said filter transfer function is proportional to
Claim 18
Dependent Claim
37 words
Apparatus as recited in claim 12 wherein said compensating filter means comprises a. operational amplifier means, b. input impedance means connected to said operational amplifier means, and c. feedback impedance means connected to said operational amplifier means.
References Cited (Backward Citations)
US3792363A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-04-21 | 1978-10-21 | 1979-04-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-21 | 1982-10-21 | 1983-04-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-21 | 1986-10-21 | 1987-04-22 | $7700.00 | Window Closed / Lapsed |