US3824015A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of, and apparatus for, the optical measurement of the speed at a moving product
Assignee: Institut de Recherches de la Siderurgie Francaise IRSID
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Filing: 1972-10-24
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Granted: 1974-07-16
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Expires: 1992-10-24
Abstract
Abstract Two similar random time delayed signals representing common characteristics of moving discrete objects or products are picked up by detecting means arranged adjacent to the path of the objects and converted to digital signals. The digital signals are applied to a correlator provided with time delay means, the correlator generating two values of the correlation function of the two signals. These two values are compared to form a control signal for controlling the time delay means through a voltage frequency converter, the initial value of the time delay being fixed by means of a signal generated by an apparatus measuring the speed of the object extremity, said latter-named signal being applied to the input of the voltage frequency converter through summing means receiving the control signal of the time delaying means.
Inventors
- 👤 P Petit
- 👤 P Verjux
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 13:26
CPC Classifications
B; B21; B21B; B21B38/00; G; G01; G01P; G01P3/00; G01P3/64; G01P3/80; G01P3/806; B21B2275/00; B21B2275/02; B21B2275/06
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
307 words
A method for measuring the speed of a moving discontinuous product comprising: detecting first and second electricAl signals at two spaced apart points in the direction of motion of the product, whereby said first signal has a leading edge representative of the passage of the forward edge of the product and a trailing part having a random pattern representative of surface characteristics of the product, and said second electrical signal has a form substantially similar to the form of said first electrical signal, said second signal being delayed relative to said first signal by a time interval that is a function of the distance between said two points and the speed to be measured; measuring the time interval between the leading edges of said first and second electrical signals and deriving therefrom a third signal substantially representative of the mean speed of the product between the respective instants of passage of the forward edge of said product at said two points; generating a fourth signal and a fifth signal by delaying said first electrical signal by two different time delays having an initial mean value that is a function of said third signal; generating two values of the correlation function of said first and second electrical signals by multiplying and integrating respectively said second and fourth signal and said second and fifth signal, whereby said two values of the correlation function correspond to the two values of the time delays applied to said first signal; deriving a differential error signal from said two values of the correlation function; and controlling the time delays applied to said first signal to respectively generate said fourth and said fifth signal so as to maintain said differential error signal at substantially zero; whereby the speed value of said product may be continuously derived from the mean value of said time delays.
Claim 2
Independent Claim
307 words
A method for measuring the speed of a moving discontinuous product comprising: detecting first and second electricAl signals at two spaced apart points in the direction of motion of the product, whereby said first signal has a leading edge representative of the passage of the forward edge of the product and a trailing part having a random pattern representative of surface characteristics of the product, and said second electrical signal has a form substantially similar to the form of said first electrical signal, said second signal being delayed relative to said first signal by a time interval that is a function of the distance between said two points and the speed to be measured; measuring the time interval between the leading edges of said first and second electrical signals and deriving therefrom a third signal substantially representative of the mean speed of the product between the respective instants of passage of the forward edge of said product at said two points; generating a fourth signal and a fifth signal by delaying said first electrical signal by two different time delays having an initial mean value that is a function of said third signal; generating two values of the correlation function of said first and second electrical signals by multiplying and integrating respectively said second and fourth signal and said second and fifth signal, whereby said two values of the correlation function correspond to the two values of the time delays applied to said first signal; deriving a differential error signal from said two values of the correlation function; and controlling the time delays applied to said first signal to respectively generate said fourth and said fifth signal so as to maintain said differential error signal at substantially zero; whereby the speed value of said product may be continuously derived from the mean value of said time delays.
Claim 3
Independent Claim
381 words
An apparatus for measuring the speed of a moving discontinuous product comprising first and second detection means positioned along the path of the product in a spaced apart relationship in the direction of motion of said product for generating first electrical signal and a second electrical signal respectively, said second signal being time-delayed relative to said first signal, whereby said first and second signals represent common characteristics of the product and each having a leading edge representative of the passage of the forward edge of the product, and a trailing part having a random pattern representative of surface characteristics of the product; controllable delay means connected to said first detection means for providing two signals having different delays with respect to said first signal; correlation function generation means, means applying said delayed signals and said second signal to said correlating function generation means, said correlation function generation means being adapted to generate two values of the correlation function of said first and second electrical signals; a differential amplifier connected to said correlation function generator means for generating an error signal from said two values of the correlation function; control means having an input connected to said differential amplifier for receiving said error signal, and an output connected to said delay means for controlling the delay in said delay means; and speed measuring means having first and second inputs connected to said first and said second detection measn respectively, and having an output connected to the input of said control means; said speed measuring means comprising time measuring means for generating a signal corresponding to the time interval between the leading edges of said first and second electrical signals; and inversion means connected to said time measuring means for generating an output signal representative of the inverse value of said time interval; whereby said output signal is substantially representative of the mean value of the speed of the product between the respective instants of passage of the forward edge of said product past said fiRst and second detection means, and means applying said output signal to the input of said control means in order to set the initial mean value of the two delays in said delay means at a value that is a function of said mean speed of the product.
Claim 4
Independent Claim
381 words
An apparatus for measuring the speed of a moving discontinuous product comprising first and second detection means positioned along the path of the product in a spaced apart relationship in the direction of motion of said product for generating first electrical signal and a second electrical signal respectively, said second signal being time-delayed relative to said first signal, whereby said first and second signals represent common characteristics of the product and each having a leading edge representative of the passage of the forward edge of the product, and a trailing part having a random pattern representative of surface characteristics of the product; controllable delay means connected to said first detection means for providing two signals having different delays with respect to said first signal; correlation function generation means, means applying said delayed signals and said second signal to said correlating function generation means, said correlation function generation means being adapted to generate two values of the correlation function of said first and second electrical signals; a differential amplifier connected to said correlation function generator means for generating an error signal from said two values of the correlation function; control means having an input connected to said differential amplifier for receiving said error signal, and an output connected to said delay means for controlling the delay in said delay means; and speed measuring means having first and second inputs connected to said first and said second detection measn respectively, and having an output connected to the input of said control means; said speed measuring means comprising time measuring means for generating a signal corresponding to the time interval between the leading edges of said first and second electrical signals; and inversion means connected to said time measuring means for generating an output signal representative of the inverse value of said time interval; whereby said output signal is substantially representative of the mean value of the speed of the product between the respective instants of passage of the forward edge of said product past said fiRst and second detection means, and means applying said output signal to the input of said control means in order to set the initial mean value of the two delays in said delay means at a value that is a function of said mean speed of the product.
Claim 5
Independent Claim
214 words
A method for measuring the speed of a moving discontinuous object having a detectable discontinuity, of the type wherein first and second detectors are provided at points spaced apart in the direction of movement of the object to provide first and second signals having leading edges corresponding to the passage of the object and trailing parts with random patterns representative of surface characteristics of the objects, comprising producing a third signal corresponding to the time interval between the leading edges of said first and second signals, producing fourth and fifth signals that have different delays with respect to said first signal, initially controlling the delays of said fourth and fifth signals whereby the mean delay is a function of said third signal, multiplying each of said fourth and fifth signals with said second signal and integrating the results of the multiplication steps to produce two values of the correlation function of said first and second signals, deriving a differential error signal from the true values of the correlation function, and controlling the delays of said fourth and fifth signals as a function of said error signal in a sense to reduce the amplitude of the error signal, whereby the mean value of the delays of the fourth and fifth signals correspond to said speed.
Claim 6
Independent Claim
214 words
A method for measuring the speed of a moving discontinuous object having a detectable discontinuity, of the type wherein first and second detectors are provided at points spaced apart in the direction of movement of the object to provide first and second signals having leading edges corresponding to the passage of the object and trailing parts with random patterns representative of surface characteristics of the objects, comprising producing a third signal corresponding to the time interval between the leading edges of said first and second signals, producing fourth and fifth signals that have different delays with respect to said first signal, initially controlling the delays of said fourth and fifth signals whereby the mean delay is a function of said third signal, multiplying each of said fourth and fifth signals with said second signal and integrating the results of the multiplication steps to produce two values of the correlation function of said first and second signals, deriving a differential error signal from the true values of the correlation function, and controlling the delays of said fourth and fifth signals as a function of said error signal in a sense to reduce the amplitude of the error signal, whereby the mean value of the delays of the fourth and fifth signals correspond to said speed.
Claim 7
Dependent Claim
283 words
In an apparatus for measuring the speed of a moving discontinuous object having a detectable discontinuity, of the type wherein first and second detectors are provided at points spaced apart in the direction of movement of the object to provide first and second signals having leading edges corresponding to the passage of the object and trailing parts with random patterns representative of surface characteristics of the objects; the improvement comprising controllable and delay means connected to receive said second signal for producing fourth and fifth signals that have different delays with respect to said second signal, multiplying an integrating means connected to separately multiply each of said fourth and fifth signals with said first signal and to integrate the results of the multiplication for providing signals corresponding to two values of the correlation function of the first and second signals, differential amplifier means connected to said multiplying and integrating means for providing an error signal from the signals corresponding to the two values of the correlation function, means responsive to said error signal connected to control the mean delay of the delays in said delay means in the sense to reduce said error signal, whereby the speed of said object is a function of said mean delay, means connected to said first and second detectors for producing a third signal that is an inverse function of the time interval between the leading edges of said first and second signal, and means applying said third signal to said means for controlling said mean delay for setting the initial mean value of the delays of the fourth and fifth signals whereby said initial mean value is a function of the mean speed of said object.
Claim 8
Dependent Claim
283 words
In an apparatus for measuring the speed of a moving discontinuous object having a detectable discontinuity, of the type wherein first and second detectors are provided at points spaced apart in the direction of movement of the object to provide first and second signals having leading edges corresponding to the passage of the object and trailing parts with random patterns representative of surface characteristics of the objects; the improvement comprising controllable and delay means connected to receive said second signal for producing fourth and fifth signals that have different delays with respect to said second signal, multiplying an integrating means connected to separately multiply each of said fourth and fifth signals with said first signal and to integrate the results of the multiplication for providing signals corresponding to two values of the correlation function of the first and second signals, differential amplifier means connected to said multiplying and integrating means for providing an error signal from the signals corresponding to the two values of the correlation function, means responsive to said error signal connected to control the mean delay of the delays in said delay means in the sense to reduce said error signal, whereby the speed of said object is a function of said mean delay, means connected to said first and second detectors for producing a third signal that is an inverse function of the time interval between the leading edges of said first and second signal, and means applying said third signal to said means for controlling said mean delay for setting the initial mean value of the delays of the fourth and fifth signals whereby said initial mean value is a function of the mean speed of said object.
Claim 9
Dependent Claim
59 words
The apparatus of claim 4 wherein said delay means comprises a shift register having an input and two fixed outputs, means applying said second signal to said input, and means deriving said fourth and fifth signals from separate outputs of said shift register, and wherein said control means is a voltage to frequency converter connected to said shift register.
Claim 10
Dependent Claim
92 words
The apparatus of claim 5 wherein said means for producing said third signal comprises oscilator means, counter means, gate means connected to receive said first and second signals for applying the output of said oscilator means to said counter means only during the time interval between the leading edges of said first and second signals, digital to analogue converter means, and means applying a digital signal that is a function of the count of said counter means to said converter means whereby the output of said converter means is said third signal.
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) | 1977-07-15 | 1978-01-14 | 1978-07-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-07-15 | 1982-01-14 | 1982-07-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-07-15 | 1986-01-14 | 1986-07-16 | $7700.00 | Window Closed / Lapsed |