US3750019A — Speed detection method and apparatus

Claim 1

Independent Claim 200 words

The method of detecting the speed of an object moving along a given path past a sensor which develops two electrical signals, each enduring for a time interval that varies inversely with the speed of the moving object and that also varies as an inverse function of the distance between the object and the sensor, said signals being spaced by a time gap that varies inversely with the speed of the moving object and that also varies as a function of the distance between the object and the sensor, said method comprising the following steps: A. maintaining a capacitor circuit in an initial charge condition before initiation of said signals; B. initiating a change in the charge condition of said capacitor circuit through a first network having a given time constant upon initiation of the first of said signals; C. continuing said change in the charge condition of said capacitor circuit through a modified network having a substantially different time constant upon expiration of the first signal; and D. interrupting the change in charge condition of said capacitor circuit upon initiation of the second signal, the residual charge on the capacitor circuit being indicative of the speed of the object.

Claim 2

Independent Claim 200 words

The method of detecting the speed of an object moving along a given path past a sensor which develops two electrical signals, each enduring for a time interval that varies inversely with the speed of the moving object and that also varies as an inverse function of the distance between the object and the sensor, said signals being spaced by a time gap that varies inversely with the speed of the moving object and that also varies as a function of the distance between the object and the sensor, said method comprising the following steps: A. maintaining a capacitor circuit in an initial charge condition before initiation of said signals; B. initiating a change in the charge condition of said capacitor circuit through a first network having a given time constant upon initiation of the first of said signals; C. continuing said change in the charge condition of said capacitor circuit through a modified network having a substantially different time constant upon expiration of the first signal; and D. interrupting the change in charge condition of said capacitor circuit upon initiation of the second signal, the residual charge on the capacitor circuit being indicative of the speed of the object.

Claim 3

Dependent Claim 59 words

The method of detecting the speed of a moving object, according to claim 1, in which said capacitor circuit is charged to a given initial voltage in step A, discharged at a first rate determined by said given time constant in step B, and discharged at a substantially faster rate determined by said different time constant in step C.

Claim 4

Dependent Claim 30 words

actuating said secondary switching means in each sampler to connect said capacitor circuit to said secondary network in each sampler upon termination of the sensor signal for that sampler; and

Claim 5

Dependent Claim 30 words

actuating said secondary switching means in each sampler to connect said capacitor circuit to said secondary network in each sampler upon termination of the sensor signal for that sampler; and

Claim 6

Dependent Claim 110 words

actuating said preliminary switching means and said secondary switching means in each sampler to disconnect said capacitor circuit from both said networks, in each sampler, upon initiation of the sensor signal for the other sampler or upon expiration of an extended time interval longer than the longest possible time gap within said speed range, whichever first ocurs; comparison means for comparing the residual charges on said capacitor circuits to determine which has changed the least from said initial charge condition and thereby determine the direction of movement of said object; and output means for measuring the terminal charge on the least-changed capacitor circuit to determine the speed of said object.

Claim 7

Dependent Claim 110 words

actuating said preliminary switching means and said secondary switching means in each sampler to disconnect said capacitor circuit from both said networks, in each sampler, upon initiation of the sensor signal for the other sampler or upon expiration of an extended time interval longer than the longest possible time gap within said speed range, whichever first ocurs; comparison means for comparing the residual charges on said capacitor circuits to determine which has changed the least from said initial charge condition and thereby determine the direction of movement of said object; and output means for measuring the terminal charge on the least-changed capacitor circuit to determine the speed of said object.

Claim 8

Dependent Claim 61 words

The method of detecting the speed of a moving object, according to claim 1, including the further steps of modifying the charge on an additional storage capacitor in accordance with the terminal charge condition of said capacitor circuit at step D, and subsequently holding the charge on the additional storage capacitor, independently of changes in charge condition of said capacitor circuit.

Claim 9

Dependent Claim 51 words

The method of detecting the speed of a moving object, according to claim 3, including the further step of restoring said capacitor circuit ot its initial charge condition, after step D and after holding of the charge on said storage capacitor has been initiated, in preparation for a subsequent speed measurement.

Claim 10

Independent Claim 379 words

The method of detecting the velocity of an object moving along a given path past a sensor which develops two electrical signals on different circuits, each signal enduring for a time interval that varies inversely with the speed of the moving object and that also varies as an inverse function of the distance between the object and the sensor, said signals being spaced by a time gap that varies inversely with the speed of the moving object and that also varies as a function of the distance between the object and the sensor, within a given speed range, said method comprising the following stEps: A. maintaining a first capacitor circuit and a second capacitor circuit in an initial charge condition before initiation of said signals; B. initiating a change in the charge condition of said first capacitor circuit through a first network having a given time constant upon initiation of one of said signals; C. continuing said change in the charge condition of said first capacitor circuit through a modified network having a substantially different time constant upon expiration of said one signal; D. interrupting the change in charge condition of said first capacitor circuit upon expiration of an extended time interval longer than the longest possible time gap within said speed range or upon initiation of the other signal, whichever first occurs; E. initiating a change in the charge condition of said second capacitor circuit through a second network having a time constant equal to said given time constant upon initiation of the other signal; F. continuing said change in the charge condition of said second capacitor circuit through a modified discharge network having a time constant equal to said different time constant upon expiration of said other signal; G. interrupting the change in charge condition of said second capacitor circuit upon expiration of an extended time interval longer than the longest possible time gap within said speed range or upon initiation of said one signal, whichever first occurs; and H. comparing the residual charges on said capacitor circuits to determine which charge has changed the least from the initial charge condition, the residual charge on the least-changed capacitor circuit being indicative of the speed of the object and the least-changed capacitor circuit identifying the direction of movement.

Claim 11

Independent Claim 379 words

The method of detecting the velocity of an object moving along a given path past a sensor which develops two electrical signals on different circuits, each signal enduring for a time interval that varies inversely with the speed of the moving object and that also varies as an inverse function of the distance between the object and the sensor, said signals being spaced by a time gap that varies inversely with the speed of the moving object and that also varies as a function of the distance between the object and the sensor, within a given speed range, said method comprising the following stEps: A. maintaining a first capacitor circuit and a second capacitor circuit in an initial charge condition before initiation of said signals; B. initiating a change in the charge condition of said first capacitor circuit through a first network having a given time constant upon initiation of one of said signals; C. continuing said change in the charge condition of said first capacitor circuit through a modified network having a substantially different time constant upon expiration of said one signal; D. interrupting the change in charge condition of said first capacitor circuit upon expiration of an extended time interval longer than the longest possible time gap within said speed range or upon initiation of the other signal, whichever first occurs; E. initiating a change in the charge condition of said second capacitor circuit through a second network having a time constant equal to said given time constant upon initiation of the other signal; F. continuing said change in the charge condition of said second capacitor circuit through a modified discharge network having a time constant equal to said different time constant upon expiration of said other signal; G. interrupting the change in charge condition of said second capacitor circuit upon expiration of an extended time interval longer than the longest possible time gap within said speed range or upon initiation of said one signal, whichever first occurs; and H. comparing the residual charges on said capacitor circuits to determine which charge has changed the least from the initial charge condition, the residual charge on the least-changed capacitor circuit being indicative of the speed of the object and the least-changed capacitor circuit identifying the direction of movement.

Claim 12

Dependent Claim 56 words

The method of detecting the velocity of a moving object, according to claim 5, in which the comparison of step H is initiated immediately following the first interruption of change in charge condition to occur (steps D and G), the direction of movement being indicated by a crossover between the charge conditions of said capacitor circuits.

Claim 13

Dependent Claim 90 words

The method of detecting the velocity of a moving object, according to claim 6, comprising the following additional steps: I. Modifying the charge on a storage capacitor in accordance with the terminal charge condition of the least-changed capacitor circuit as determined by step H, and subsequently holding the charge on said storage capacitor, thereafter, independently of further changes in charge condition of said capacitor circuits; and J. restoring both capacitor circuits to said initial charge condition, upon completion of steps A through G, in preparation for a subsequent speed measurement.

Claim 14

Dependent Claim 63 words

The method of detecting the velocity of a moving object, according to claim 7, in which said capacitor circuits are charged to a given initial voltage in step A, discharged at a first rate determined by said given time constant in steps B and E, and discharged at a substantially faster rate determined by said different time constant in steps C and F.

Claim 15

Dependent Claim 298 words

A speed detector for detecting the speed of an object moving along a given path past a sensor which develops two electrical signals each enduring for a time interval that varies inversely with the speed of the moving object and that also varies as an inverse function of the distance between the object and the sensor, said signals being spaced by a time gap that varies inversely with the speed of the moving object and that also varies as a function of the distance between the object and the sensor, said speed detector comprising: a capacitor circuit; charge-establishing means for normally maintaining said capacitor circuit in a given charge condition; a preliminary network, having a given time constant when connected to said capacitor circuit; a secondary network having a substantially different time constant when connected to said capacitor circuit; charge switching means, preliminary switching means, and secondary switching means for connecting said capacitor circuit to said charge-establishing means, to said preliminary network, and to said secondary network, respectively; logic means, coupled to said sensor, and to all of said switching means, for actuating said switching means in accordance with the following operational program: A. actuating said charge switching means and said preliminary switching means to disconnect said capacitor circuit from said charge-establishing means and to connect said capacitor circuit to said preliminary network upon initiation of the first of said signals; B. actuating said secondary switching means to connect said capacitor circuit to said secondary network upon termination of said first signal; and C. actuating said preliminary switching means and said secondary switching means to disconnect said capacitor circuit from both said networks upon initiation of the second signal; and output means for measuring the terminal charge on said capacitor circuit to determine the speed of said object.

Claim 16

Dependent Claim 298 words

A speed detector for detecting the speed of an object moving along a given path past a sensor which develops two electrical signals each enduring for a time interval that varies inversely with the speed of the moving object and that also varies as an inverse function of the distance between the object and the sensor, said signals being spaced by a time gap that varies inversely with the speed of the moving object and that also varies as a function of the distance between the object and the sensor, said speed detector comprising: a capacitor circuit; charge-establishing means for normally maintaining said capacitor circuit in a given charge condition; a preliminary network, having a given time constant when connected to said capacitor circuit; a secondary network having a substantially different time constant when connected to said capacitor circuit; charge switching means, preliminary switching means, and secondary switching means for connecting said capacitor circuit to said charge-establishing means, to said preliminary network, and to said secondary network, respectively; logic means, coupled to said sensor, and to all of said switching means, for actuating said switching means in accordance with the following operational program: A. actuating said charge switching means and said preliminary switching means to disconnect said capacitor circuit from said charge-establishing means and to connect said capacitor circuit to said preliminary network upon initiation of the first of said signals; B. actuating said secondary switching means to connect said capacitor circuit to said secondary network upon termination of said first signal; and C. actuating said preliminary switching means and said secondary switching means to disconnect said capacitor circuit from both said networks upon initiation of the second signal; and output means for measuring the terminal charge on said capacitor circuit to determine the speed of said object.

Claim 17

Dependent Claim 59 words

A speed detector according to claim 9, in which said capacitor circuit comprises a plurality of individual capacitors connected in series with each other, and in which said charge-establishing means, said preliminary network and said secondary network each include a corresponding plurality of individual resistors each connectable in parallel with a selected one of the capacitors in said network.

Claim 18

Dependent Claim 148 words

A speed detector according to claim 10, in which said charge switching means comprises a plurality of solid-state switching devices, one connected in series with each resistor in said charge-establishing means, said preliminary switching means comprises a plurality of solid-state switching devices, one connected in series with each resistor in said preliminary network, and said secondary switching means comprises a plurality solid-state switching devices, one connected in series with each resistor in said secondary network, for connecting said resistors to and disconnecting said resistors from said capacitors in said capacitor circuit, all of said switching devices being coupled to said logic means. 12. A speed detector according to claim 10, in which said charge-establishing means comprises a regulated voltage supply for charging said capacitor circuit to a given voltage, and in which said preliminary network and said secondary network comprise discharge resistor networks for discharging said capacitor circuit.

Claim 19

Dependent Claim 44 words

A speed detector according to claim 9, in which said output means comprises a sample-hold amplifier for maintaining the terminal charge from said capacitor circuit in storage for a substantial period of time, independently of further changes in the charge on said capacitor circuit.

Claim 20

Dependent Claim 229 words

A speed detector for detecting, within given speed range, the speed of an object moving along a given path past a sensor which develops two electrical signals A and B occurring in a sequence indicative of the direction of movement of said object and each enduring for a time interval that varies inversely with the speed of the moving object and that also varies as an inverse function of the distance between the object and the sensor, said signals being spaced by a time gap that varies inversely with the speed of the moving object and that also varies as a function of the distance between the object and the sensor, said speed detector comprising: an A signal sampler and a B signal sampler, each including: a capacitor circuit; a charge-estabshing means for normally maintaining said capacitor circuit in an initial charge condition; a preliminary network having a given time constant when connected to said capacitor circuit; a secondary network having a substantially different time constant when connected to said capacitor circuit; and charge switching means, preliminary switching means, and secondary switching means for connecting said capacitor circuit to said charge-establishing means, to said preliminary network, and to said secondary network, respectively; logic means, coupled to said sensor and to the switching means in both said samplers, for actuating said switching means in accordance with the following operational program:

Claim 21

Dependent Claim 229 words

A speed detector for detecting, within given speed range, the speed of an object moving along a given path past a sensor which develops two electrical signals A and B occurring in a sequence indicative of the direction of movement of said object and each enduring for a time interval that varies inversely with the speed of the moving object and that also varies as an inverse function of the distance between the object and the sensor, said signals being spaced by a time gap that varies inversely with the speed of the moving object and that also varies as a function of the distance between the object and the sensor, said speed detector comprising: an A signal sampler and a B signal sampler, each including: a capacitor circuit; a charge-estabshing means for normally maintaining said capacitor circuit in an initial charge condition; a preliminary network having a given time constant when connected to said capacitor circuit; a secondary network having a substantially different time constant when connected to said capacitor circuit; and charge switching means, preliminary switching means, and secondary switching means for connecting said capacitor circuit to said charge-establishing means, to said preliminary network, and to said secondary network, respectively; logic means, coupled to said sensor and to the switching means in both said samplers, for actuating said switching means in accordance with the following operational program:

Claim 22

Dependent Claim 56 words

A velocity detector according to claim 14, in which the capacitor circuit in each sampler comprises a plurality of capacitors connected in series, and in which said charge-establishing means, said preliminary network, and said secondary network, in each sampler, each comprises a corresponding plurality of resistors individually connectable in parallel with individual ones of said capacitors.

Claim 23

Dependent Claim 77 words

A velocity detector according to claim 15, in which said charge-establishing means in each sampler includes a voltage-regulated power supply for charging the capacitor circuit of said sampler to an initial voltage, the distribution of charge on the individual capacitors in the capacitor circuit being determined by the relative resistances of the resistors in said charge-establishing means, and in which said preliminary and secondary networks in each sampler comprise discharge networks for discharging their respective capacitor circuits.

Claim 24

Dependent Claim 55 words

A velocity detector according to claim 16, in which there are three capacitors in said capacitor circuit in each sampler and in which the capacitors in each capacitor circuit and the resistors in each preliminary network are selected to discharge said capacitors approximately in accordance with the function F(t) 235.5e 156.1t+ 54.5e 29.8t+ 9.0e 4.6t+1.

Claim 25

Dependent Claim 105 words

A velocity detector according to claim 16 in which said charge switching means comprises a plurality of solid-state switching devices, one in series with each resistor in said charge-establishing means, said preliminary switching means comprises a plurality of solid-state switching devices, one connected in series with each resistor in said preliminary network, and said secondary switching means comprises a plurality of solid-state switching devices, one connected in series with each resistor in said secondary network, in each sampler, for connecting said resistors to and disconnecting said resistors from said capacitors in said capacitor circuits, all of said switching devices being coupled to said logic means.

Claim 26

Dependent Claim 20 words

A velocity detector according to claim 14 in which each sampler includes a sample-hold amplifier connected to said capacitor circuit.

Claim 27

Dependent Claim 58 words

A velocity detector according to claim 19 in which said comparison means includes a crossover detector comprising a differential amplifier having two inputs, each input connected to the output of the sAmple-hold amplifier in a respective one of said samplers, the output of said differential amplifier having a polarity indicative of the direction of movement of said object.

Claim 28

Dependent Claim 96 words

A velocity detector according to claim 19, in which said output means comprises an output sample-hold amplifier, a first solid-state switching device connecting the input of said output amplifier to the output of said A sampler, and a second solid-state switching device connecting the input of said output amplifier to the output of said B sampler, said solid-state switching devices being actuated by said comparison means so that said output sample-hold amplifier stores the terminal charge of said least-changed capacitor circuit even though the capacitor circuits of both samplers are returned to their initial charge condition.

Claim 29

Independent Claim 213 words

The method of detecting the speed of an object moving along a given path past a sensor which develops two electrical sensor signals, each enduring for a time interval that varies inversely with the speed of the moving object and that also varies as an inverse function of the distance between the object and the sensor, said sensor signals being spaced by a time gap that varies inversely with the speed of the moving object and that also varies as a function of the distance between the object and the sensor, said method comprising the following steps: A. maintaining an electrical signal storage circuit in an initial signal storage condition before initiation of said sensor signals; B. initiating a change in the signal storage condition of said storage circuit through a first network having a given time constant upon initiation of the first of said sensor signals; C. continuing said change in the signal storage condition of said storage circuit through a modified network having a substantially different time constant upon expiration of the first sensor signal; and D. interrupting the change in signal storage condition of said storage circuit upon initiation of the second sensor signal, the residual signal stored in the storage circuit being indicative of the speed of the object.

Claim 30

Independent Claim 213 words

The method of detecting the speed of an object moving along a given path past a sensor which develops two electrical sensor signals, each enduring for a time interval that varies inversely with the speed of the moving object and that also varies as an inverse function of the distance between the object and the sensor, said sensor signals being spaced by a time gap that varies inversely with the speed of the moving object and that also varies as a function of the distance between the object and the sensor, said method comprising the following steps: A. maintaining an electrical signal storage circuit in an initial signal storage condition before initiation of said sensor signals; B. initiating a change in the signal storage condition of said storage circuit through a first network having a given time constant upon initiation of the first of said sensor signals; C. continuing said change in the signal storage condition of said storage circuit through a modified network having a substantially different time constant upon expiration of the first sensor signal; and D. interrupting the change in signal storage condition of said storage circuit upon initiation of the second sensor signal, the residual signal stored in the storage circuit being indicative of the speed of the object.

Claim 31

Independent Claim 406 words

The method of detecting the velocity of an object moving along a given path past a sensor which develops two electrical sensor signals on different circuits, each sensor signal enduring for a time interval that varies inversely with the speed of the moving object and that also varies as an inverse function of the distance between the object and the sensor, said sensor signals being spaced by a time gap that varies inversely with the speed of the moving object and that also varies as a function of the distance between the object and the sensor, within a given speed range, said method comprising the following steps: A. maintaining a first electrical signal storage circuit and a second electrical signal storage circuit in an initial signal storage condition before initiation of said sensor signals; B. initiating a change in the signal storage condition of said first signal storage circuit through a first network having a given time constant upon initiation of one of said sensor signals; C. continuing said change in the signal storage condition of said first storage circuit through a modified network having a substantially different time constant upon expiration of said one sensor signal; D. interrupting the change in signal storage condition of said first storage circuit upon expiration of an extended time interval longer than the longest possible time gap within said speed range or upon initiation of the other sensor signal, whichever first occurs; E. initiating a change in the signal storage condition of said second storage circuit through a second network having a time constant equal to said given time constant upon initiation of the other sensor signal; F. continuing said change in the signal storage condition of said second storage circuit through a modified discharge network having a time constant equal to said difFerent time constant upon expiration of said other sensor signal; G. interrupting the change in signal storage condition of said second storage circuit upon expiration of an extended time interval longer than the longest possible time gap within said speed range or upon initiation of said one sensor signal, whichever first occurs; and H. comparing the residual signals stored in said storage circuits to determine which stored signal has changed the least from the initial signal storage condition, the residual stored signal in the least-changed storage circuit being indicative of the speed of the object and the least-changed signal storage circuit identifying the direction of movement.

Claim 32

Independent Claim 406 words

The method of detecting the velocity of an object moving along a given path past a sensor which develops two electrical sensor signals on different circuits, each sensor signal enduring for a time interval that varies inversely with the speed of the moving object and that also varies as an inverse function of the distance between the object and the sensor, said sensor signals being spaced by a time gap that varies inversely with the speed of the moving object and that also varies as a function of the distance between the object and the sensor, within a given speed range, said method comprising the following steps: A. maintaining a first electrical signal storage circuit and a second electrical signal storage circuit in an initial signal storage condition before initiation of said sensor signals; B. initiating a change in the signal storage condition of said first signal storage circuit through a first network having a given time constant upon initiation of one of said sensor signals; C. continuing said change in the signal storage condition of said first storage circuit through a modified network having a substantially different time constant upon expiration of said one sensor signal; D. interrupting the change in signal storage condition of said first storage circuit upon expiration of an extended time interval longer than the longest possible time gap within said speed range or upon initiation of the other sensor signal, whichever first occurs; E. initiating a change in the signal storage condition of said second storage circuit through a second network having a time constant equal to said given time constant upon initiation of the other sensor signal; F. continuing said change in the signal storage condition of said second storage circuit through a modified discharge network having a time constant equal to said difFerent time constant upon expiration of said other sensor signal; G. interrupting the change in signal storage condition of said second storage circuit upon expiration of an extended time interval longer than the longest possible time gap within said speed range or upon initiation of said one sensor signal, whichever first occurs; and H. comparing the residual signals stored in said storage circuits to determine which stored signal has changed the least from the initial signal storage condition, the residual stored signal in the least-changed storage circuit being indicative of the speed of the object and the least-changed signal storage circuit identifying the direction of movement.

Claim 33

Dependent Claim 58 words

The method of detecting the velocity of a moving object, according to claim 23, in which the comparison of step H is initiated immediately following the first interruption of change in signal storage condition to occur (steps D and G), the direction of movement being indicated by a crossover between the signal storage conditions of said storage circuits.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1976-07-30	1977-01-29	1977-07-31	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1980-07-30	1981-01-29	1981-07-31	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1984-07-30	1985-01-29	1985-07-31	$7700.00	Window Closed / Lapsed

Speed detection method and apparatus

Abstract

Inventors

Bibliographic Details

Claims Analysis

References Cited (Backward Citations)

USPTO Annuity & Maintenance Windows

Assigned Categories & Tags

Assign Category Tag