Patent US4484281A successfully refreshed from Google Patents.
US4484281A
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Apparatus for generating a lead signal in an antiskid system
Assignee: Crane Co
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Filing: 1982-08-17
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Granted: 1984-11-20
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Expires: 2002-08-17
Abstract
Abstract An antiskid braking system includes an improved apparatus for generating a lead signal to provide lead compensation. According to one feature of this apparatus the gain is a function of the algebraic sign of the input signal to the apparatus. Preferably, higher gains are used when the input signal corresponds to wheel deceleration than when it corresponds to acceleration. Another feature of the invention is that the apparatus operates to reduce the magnitude of the lead signal when it exceeds a limit value, preferably by clamping the lead signal to a maximum magnitude. A third feature is that first and second order lead signals are utilized in such a way as to preclude adverse cancellation between the two.
Inventors
- 👤 Thomas Skarvada
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 08:07
CPC Classifications
B; B60; B60T; B60T8/00; B60T8/17; B60T8/176; B60T8/1761; B60T8/17616
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
194 words
In an antiskid system including a wheel, a brake coupled to the wheel, means for generating a wheel signal indicative of wheel rotation, means responsive to the wheel signal for generating a brake control signal, and means responsive to the brake control signal for reducing braking action of the brake, the improvement comprising: means for generating a first lead signal as a function of one selected time derivative of the angular velocity of the wheel; means for generating a second lead signal as a function of another selected time derivative of the angular velocity of the wheel, different from the one selected time derivative, said second lead signal on occasion having a polarity different from that of the first lead signal; means for generating a composite lead signal as a function of the first and second lead signals, such that the composite lead signal is no less than the greater of the first and second lead signals, even when the polarity of the first lead signal differs from that of the second lead signal; and means for modifying the brake control signal as a function of the composite lead signal to provide lead compensation.
Claim 2
Dependent Claim
194 words
In an antiskid system including a wheel, a brake coupled to the wheel, means for generating a wheel signal indicative of wheel rotation, means responsive to the wheel signal for generating a brake control signal, and means responsive to the brake control signal for reducing braking action of the brake, the improvement comprising: means for generating a first lead signal as a function of one selected time derivative of the angular velocity of the wheel; means for generating a second lead signal as a function of another selected time derivative of the angular velocity of the wheel, different from the one selected time derivative, said second lead signal on occasion having a polarity different from that of the first lead signal; means for generating a composite lead signal as a function of the first and second lead signals, such that the composite lead signal is no less than the greater of the first and second lead signals, even when the polarity of the first lead signal differs from that of the second lead signal; and means for modifying the brake control signal as a function of the composite lead signal to provide lead compensation.
Claim 3
Dependent Claim
27 words
The invention of claim 1 wherein the one selected time derivative is the first time derivative and the other selected time derivative is the second time derivative.
Claim 4
Dependent Claim
36 words
The invention of claim 1 wherein the means for generating the composite lead signal is operative to set the composite lead signal to a value proportional to the greater of the first and second lead signals.
Claim 5
Dependent Claim
172 words
In an antiskid system including a wheel, a brake coupled to the wheel, means for generating a wheel signal indicative of wheel rotation, means responsive to the wheel signal for generating a brake control signal, and means responsive to the brake control signal for reducing braking action of the brake, the improvement comprising: means for generating a first lead signal as a function of one selected time derivative of the angular velocity of the wheel; means for generating a second lead signal as a function of another selected time derivative of the angular velocity of the wheel, different from the one selected time derivative; means for selecting the one of the first and second lead signals indicative of a greater reduction in braking action; means for generating a composite lead signal as a function of the selected lead signal to prevent the non-selected lead signal from interfering with the selected lead signal; and means for modifying the brake control signal as a function of the composite lead signal to provide lead compensation.
Claim 6
Dependent Claim
172 words
In an antiskid system including a wheel, a brake coupled to the wheel, means for generating a wheel signal indicative of wheel rotation, means responsive to the wheel signal for generating a brake control signal, and means responsive to the brake control signal for reducing braking action of the brake, the improvement comprising: means for generating a first lead signal as a function of one selected time derivative of the angular velocity of the wheel; means for generating a second lead signal as a function of another selected time derivative of the angular velocity of the wheel, different from the one selected time derivative; means for selecting the one of the first and second lead signals indicative of a greater reduction in braking action; means for generating a composite lead signal as a function of the selected lead signal to prevent the non-selected lead signal from interfering with the selected lead signal; and means for modifying the brake control signal as a function of the composite lead signal to provide lead compensation.
Claim 7
Dependent Claim
17 words
The invention of claim 4 wherein the composite lead signal is proportional to the selected lead signal.
Claim 8
Dependent Claim
27 words
The invention of claim 4 wherein the one selected time derivative is the first time derivative and the other selected time derivative is the second time derivative.
Claim 9
Dependent Claim
184 words
In an antiskid system including a wheel, a brake coupled to the wheel, means for generating a wheel signal indicative of wheel rotation, means responsive to the wheel signal for generating a brake control signal as a time integral function of the difference between the angular velocity of the wheel and a threshold velocity, and means responsive to the brake control signal for reducing braking action of the brake, the improvement comprising: means for generating a first lead signal as a function of a first time derivative of the angular velocity of the wheel; means for generating a second lead signal as a function of a second time derivative of the angular velocity of the wheel; means for selecting the one of the first and second lead signals indicative of a greater reduction in braking action; means for generating a composite lead signal as a function of the selected lead signal to prevent the non-selected lead signal from interfering with the selected lead signal; and means for modifying the brake control signal as a function of the composite lead signal to provide lead compensation.
Claim 10
Dependent Claim
184 words
In an antiskid system including a wheel, a brake coupled to the wheel, means for generating a wheel signal indicative of wheel rotation, means responsive to the wheel signal for generating a brake control signal as a time integral function of the difference between the angular velocity of the wheel and a threshold velocity, and means responsive to the brake control signal for reducing braking action of the brake, the improvement comprising: means for generating a first lead signal as a function of a first time derivative of the angular velocity of the wheel; means for generating a second lead signal as a function of a second time derivative of the angular velocity of the wheel; means for selecting the one of the first and second lead signals indicative of a greater reduction in braking action; means for generating a composite lead signal as a function of the selected lead signal to prevent the non-selected lead signal from interfering with the selected lead signal; and means for modifying the brake control signal as a function of the composite lead signal to provide lead compensation.
Claim 11
Dependent Claim
17 words
The invention of claim 7 wherein the composite lead signal is proportional to the selected lead signal.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-11-20 | 1988-05-21 | 1988-11-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-11-20 | 1992-05-21 | 1992-11-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-11-20 | 1996-05-21 | 1996-11-20 | $7700.00 | Window Closed / Lapsed |