US3797894A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Combination peak detector and level detector for use in an adaptive braking system
Assignee: Bendix Corp
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Filing: 1973-01-24
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Granted: 1974-03-19
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Expires: 1993-01-24
Abstract
Abstract A peak detector for use in an adaptive braking system includes a current source which supplies current to a memory capacitor to maintain the voltage thereacross equal to an input signal so long as the input signal remains above a first threshold. While the input signal is decreasing below the first threshold, current is drawn from the memory capacitor so that the voltage thereacross continues to track the input voltage. However, when the input signal subsequently begins to increase below the first threshold, diodes prevent current from entering or being drawn from the memory capacitor so that the voltage across the capacitor remains constant and equal to the negative peak value of the input signal. The voltage across the capacitor is applied as one input to a comparator while only a portion of the input signal voltage is applied as the second input to the comparator. Accordingly, when the input signal voltage increases by an amount related to the above mentioned portion the comparator generates an output.
Inventors
- 👤 R Carp
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 17:57
CPC Classifications
B; B60; B60T; B60T8/00; B60T8/17; B60T8/172; Y; Y10; Y10S; Y10S303/00; Y10S303/05
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
404 words
In an adaptive braking system which operates to produce an electrical signal correlated to the performance of a wheeled vehicle, said electrical signal having a voltage level above a base level when correlated to the performance of a decelerating vehicle wheel, and below the base level when correlated to the performance of a vehicle accelerating wheel, and which acts to relieve vehicle braking force when certain vehicle performance criteria are attained and further acts to generate an output signal which is applied to restore braking force when said electrical signal reaches a pre-determined threshold while moving away from said base level or when said electrical signal attains a peak level less than said pre-determined threshold and subsequently moves toWard said base level by a second predetermined amount, a circuit for generating said output signal in response to said electrical signal, comprising: first means for producing a voltage level essentially equal to said base voltage level; a capacitor; a first unidirectional current device; a first operational amplifier operated open looped and having first and second input terminals and an output terminal, said first means being connected to apply said voltage level to said first input terminal and said adaptive braking system being connected to apply said electrical signal to said second input terminal; a second operational amplifier having first and second input terminals and an output terminal, said second operational amplifier first input terminal being connected to receive said electrical signal, and said unidirectional current device being connected between said first operational amplifier output terminal and said second operational amplifier second input terminal; a second unidirectional current device connected between said second operational amplifier output and second input terminals; a resistor; a reference voltage level bus; a constant current device serially connected to said resistor to form a second circuit having one end connected to receive said electrical signal and another end connected to said reference voltage level bus; a third operational amplifier operated open looped and having a first input terminal connected to the junction between said resistor and said constant current device, a second input terminal connected to said second operational amplifier second input terminal, one plate of said capacitor being connected to the common connection thereof and the second plate of said capacitor being connected to said bus, and an output terminal upon which said output signal appears; and, resistance means connected between said second operational amplifier output terminal and said bus.
Claim 2
Dependent Claim
404 words
In an adaptive braking system which operates to produce an electrical signal correlated to the performance of a wheeled vehicle, said electrical signal having a voltage level above a base level when correlated to the performance of a decelerating vehicle wheel, and below the base level when correlated to the performance of a vehicle accelerating wheel, and which acts to relieve vehicle braking force when certain vehicle performance criteria are attained and further acts to generate an output signal which is applied to restore braking force when said electrical signal reaches a pre-determined threshold while moving away from said base level or when said electrical signal attains a peak level less than said pre-determined threshold and subsequently moves toWard said base level by a second predetermined amount, a circuit for generating said output signal in response to said electrical signal, comprising: first means for producing a voltage level essentially equal to said base voltage level; a capacitor; a first unidirectional current device; a first operational amplifier operated open looped and having first and second input terminals and an output terminal, said first means being connected to apply said voltage level to said first input terminal and said adaptive braking system being connected to apply said electrical signal to said second input terminal; a second operational amplifier having first and second input terminals and an output terminal, said second operational amplifier first input terminal being connected to receive said electrical signal, and said unidirectional current device being connected between said first operational amplifier output terminal and said second operational amplifier second input terminal; a second unidirectional current device connected between said second operational amplifier output and second input terminals; a resistor; a reference voltage level bus; a constant current device serially connected to said resistor to form a second circuit having one end connected to receive said electrical signal and another end connected to said reference voltage level bus; a third operational amplifier operated open looped and having a first input terminal connected to the junction between said resistor and said constant current device, a second input terminal connected to said second operational amplifier second input terminal, one plate of said capacitor being connected to the common connection thereof and the second plate of said capacitor being connected to said bus, and an output terminal upon which said output signal appears; and, resistance means connected between said second operational amplifier output terminal and said bus.
Claim 3
Dependent Claim
22 words
The circuit of claim 1 wherein said first input terminals are non-inverting input terminals and said second terminals are inverting input terminals.
Claim 4
Dependent Claim
17 words
The circuit recited in claim 2 wherein said first and third operational amplifiers are connected as comparators.
Claim 5
Dependent Claim
79 words
The circuit of claim 1 wherein said constant current device includes an NPN transistor connected to pass constant current in its collector-emitter circuit, and wherein said resistor is connected in said collector-emitter circuit, and said first unidirectional current means is connected to deliver current from the output terminal of said first operational amplifier to the first plate of said capacitor and wherein said second unidirectional current device is connected to leak current from the first plate of said capacitor.
Claim 6
Dependent Claim
19 words
The circuit of claim 4 wherein said first and second unidirectional current devices comprise first and second diodes respectively.
Claim 7
Dependent Claim
301 words
In an adaptive braking system which operates to produce an electrical signal correlated to the acceleration and deceleration of a sensed vehicle wheel, said electrical signal having a voltage level of one sense with respect to a base level when the sensed wheel is decelerating, and of opposite sense with respect to the base level when the sensed wheel is accelerating, and which acts to release vehicle braking force when certain vehicle performance criteria are attained and further acts to generate an output signal which is applied to restore braking force when said electrical signal reaches a pre-determined threshold while moving away from said base level or when said electrical signal attains a peak level less than said predetermined threshold and then subsequently moves towards the base level by a predetermined amount, a circuit for generating said output signal in response to said electrical signal, comprising: first means for producing a reference voltage level; charge storage means; operational amplifier means having first and second input terminals and an output terminal, said first input terminal being connected to receive said electrical signal; unidirectional current means connected between said second input terminal and said output terminal; first means responsive to said electrical signal and said reference voltage level for moving charges to said first input terminal while said electrical signal is displaced in a first direction from said reference voltage level and moving away therefrom, said charge storage means being connected to said second input terminal; means responsive to said electrical signal for generating a second electrical signal which is offset from said electrical signal and including means for decreasing the offset when said electrical signal attains a predetermined threshold; and, comparator means responsive to said second electrical signal and the voltage level at said second input terminal for generating said output signal.
Claim 8
Dependent Claim
301 words
In an adaptive braking system which operates to produce an electrical signal correlated to the acceleration and deceleration of a sensed vehicle wheel, said electrical signal having a voltage level of one sense with respect to a base level when the sensed wheel is decelerating, and of opposite sense with respect to the base level when the sensed wheel is accelerating, and which acts to release vehicle braking force when certain vehicle performance criteria are attained and further acts to generate an output signal which is applied to restore braking force when said electrical signal reaches a pre-determined threshold while moving away from said base level or when said electrical signal attains a peak level less than said predetermined threshold and then subsequently moves towards the base level by a predetermined amount, a circuit for generating said output signal in response to said electrical signal, comprising: first means for producing a reference voltage level; charge storage means; operational amplifier means having first and second input terminals and an output terminal, said first input terminal being connected to receive said electrical signal; unidirectional current means connected between said second input terminal and said output terminal; first means responsive to said electrical signal and said reference voltage level for moving charges to said first input terminal while said electrical signal is displaced in a first direction from said reference voltage level and moving away therefrom, said charge storage means being connected to said second input terminal; means responsive to said electrical signal for generating a second electrical signal which is offset from said electrical signal and including means for decreasing the offset when said electrical signal attains a predetermined threshold; and, comparator means responsive to said second electrical signal and the voltage level at said second input terminal for generating said output signal.
Claim 9
Dependent Claim
17 words
The circuit of claim 6 wherein said reference voltage level is essentially equal to said base level.
Claim 10
Dependent Claim
59 words
The circuit of claim 6 wherein said means for generating a second electrical signal comprises an additional circuit having said electrical signal impressed thereacross and comprising: a constant current source designed to saturate when said electrical signal attains said predetermined threshold; and, means responsive to the current flowing through said constant current source for generating said second electrical signal.
Claim 11
Dependent Claim
67 words
The circuit of claim 6 wherein said means for generating a second electrical signal comprises an additional circuit having said electrical signal impressed thereacross and comprising: a voltage source having a low impedance bias point; and, a voltage divider serially connected with said voltage source and having one end connected to said bias point, said second electrical signal being generated at a point in said voltage divider.
Claim 12
Dependent Claim
33 words
The circuit of claim 6 wherein said first and second means comprise first additional and second additional operational amplifiers respectively, said first and second additional operational amplifiers being operated open looped as comparators.
Claim 13
Dependent Claim
39 words
The circuit of claim 10 wherein said charge storage means comprises a capacitor having one plate connected to said first input terminal and including resistance means connected between said operational amplifier means output terminal and said capacitor second plate.
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) | 1977-03-18 | 1977-09-17 | 1978-03-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-03-18 | 1981-09-17 | 1982-03-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-03-18 | 1985-09-17 | 1986-03-19 | $7700.00 | Window Closed / Lapsed |