US4374422A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automatic speed control for heavy vehicles
Assignee: Bendix Corp
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Filing: 1980-10-27
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Granted: 1983-02-15
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Expires: 2000-10-27
Abstract
Abstract An automatic speed control for a heavy duty vehicle includes a controller which regulates communication between a compressed air source and an air actuated throttle mechanism. The controller generates a control signal which is a function of a speed error signal and the position of the air actuated throttle to regulate the compressed air source. The speed error signal is calculated as the difference between a commanded speed signal and an actual speed signal. To generate the control signal, the error signal and throttle position signal are operated on by different lead-lag transfer functions. These lead-lag terms are thereafter combined with a proportional speed error term to yield the desired control signal. The system further includes a throttle control feature for powering auxiliary equipment when the actual speed signal is zero. Another feature of the control limits the commanded speed signal to a set value when it exceeds a predetermined limit.
Inventors
- 👤 Patrick J. O'Keefe, Jr.
- 👤 II Harold E. Weissler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 06:21
CPC Classifications
F; F02; F02D; F02D11/00; F02D11/06; F02D11/10; F02D11/105; B; B60; B60K; B60K26/00; B60K26/04; B60K31/00; B60K31/06; B60K31/10; B60K31/102; B60K31/105; B60W; B60W50/00; B60W2050/0001; B60W2050/0002; B60W2050/0012; B60W2710/00; B60W2710/06; B60W2710/0605; F02D41/00; F02D41/02; F02D41/14; F02D41/1401; F02D2041/141
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
169 words
An automatic speed control system for a vehicle comprising means for generating a speed error signal proportional to the difference between an actual speed signal and a commanded speed signal; and means for generating a control signal as a function of said speed error signal wherein said control signal positions a throttle member regulating the actual speed of the vehicle to reduce said error signal; said control signal generating means including: means for generating a proportional error signal dependently upon said speed error signal and of the same sign as said control signal; means for generating a feedforward error signal of the opposite sign of said control signal which is proportional to the change in the speed error signal; means for generating a feedback position signal of the opposite sign of said control signal which is proportional to the change in the position of the throttle member; and means for combining said proportional error signal, said feedforward error signal, and said feedback position signal to form said control signal.
Claim 2
Dependent Claim
169 words
An automatic speed control system for a vehicle comprising means for generating a speed error signal proportional to the difference between an actual speed signal and a commanded speed signal; and means for generating a control signal as a function of said speed error signal wherein said control signal positions a throttle member regulating the actual speed of the vehicle to reduce said error signal; said control signal generating means including: means for generating a proportional error signal dependently upon said speed error signal and of the same sign as said control signal; means for generating a feedforward error signal of the opposite sign of said control signal which is proportional to the change in the speed error signal; means for generating a feedback position signal of the opposite sign of said control signal which is proportional to the change in the position of the throttle member; and means for combining said proportional error signal, said feedforward error signal, and said feedback position signal to form said control signal.
Claim 3
Dependent Claim
54 words
An automatic speed control system as defined in claim 1, wherein the vehicle includes a diesel engine having a fuel governor controlled by said throttle member, and wherein: said control signal positions said throttle member such that the speed regulation of the vehicle is not mismatched with the governing action of the fuel governor.
Claim 4
Dependent Claim
45 words
An automatic speed control system as defined in claim 2 wherein the governor is a min-max governor, and wherein: said control signal positions said throttle member such that the speed regulation of the vehicle is not mismatched with the governing action of the max-min governor.
Claim 5
Dependent Claim
45 words
An automatic speed control system as defined in claim 2, wherein the governor is an all-speed governor, and wherein: said control signal positions said throttle member such that the speed regulation of the vehicle is not mismatched with the governing action of the all-speed governor.
Claim 6
Dependent Claim
39 words
An automatic speed control system as defined in claim 1, wherein said feedforward error signal generating means includes: means for differentiating said error signal and for generating a derivative error signal proportional to the changes in said error signal.
Claim 7
Dependent Claim
35 words
An automatic speed control system as defined in claim 5, wherein said feedforward error signal generating means further includes: means for generating a historic error signal which decays with time from said derivative error signal.
Claim 8
Dependent Claim
58 words
An automatic speed control system as defined in claim 5, wherein the transfer function of said feedback error signal generating means comprises: FES=VES(S K1)/(T1 S+1) where VES is said error signal, FES is said feedforward error signal, K1 is a predetermined gain, S is the Laplace operator in the frequency domain, and T1 is a predetermined time constant.
Claim 9
Dependent Claim
41 words
An automatic speed control system as defined in claim 1, wherein said feedback position signal generating means includes: means for differentiating said throttle position signal and for generating a derivative position signal proportional to the changes in said throttle position signal.
Claim 10
Dependent Claim
34 words
An automatic speed control system as defined in claim 8, wherein said feedback position signal generating means includes: means for generating a historic position signal which decays with time from said derivative position signal.
Claim 11
Dependent Claim
59 words
An automatic speed control system as defined in claim 9, wherein the transfer function of said feedback position signal generating means comprises: FPS=THL(S K2)/(T2 S+1) where THL is said throttle position signal FPS is said feedback position signal K2 is a predetermined gain T2 is a predetermined time constant, and S is the Laplace operator in the frequency domain.
Claim 12
Dependent Claim
138 words
An automatic speed control system as defined in claim 1 wherein: the transfer function of said proportional error signal generating means comprises, PES=VES K where VES is said error signal PES is said proportional error signal, and K is a predetermined gain; the transfer function of said feedforward error signal generating means comprises, FES=VES(S K1)/(T1 S+1) where VES is said error signal, FES is said feedforward error signal, K1 is a predetermined gain, T1 is a predetermined time constant, and S is the Laplace operator in the frequency domain; and the transfer function of said feedback position signal generating means comprises, FPS=THL(S K2)/(T2 S+1) where THL is said throttle position signal FPS is said feedback position signal K2 is a predetermined gain T2 is a predetermined time constant, and S is the Laplace operator in the frequency domain.
Claim 13
Dependent Claim
21 words
An automatic speed control system as defined in claim 11, wherein: K is greater than K1 which is greater than K2.
Claim 14
Dependent Claim
16 words
An automatic speed control system as defined in claim 12, wherein: T1 is longer than T2.
Claim 15
Dependent Claim
44 words
An automatic speed control system as defined in claim 11 wherein the said vehicle includes a diesel engine having a fuel governor controlled by said throttle member, and wherein: the gain K2 varies depending upon the type of governor controlled by said throttle member.
Claim 16
Dependent Claim
45 words
An automatic speed control system as defined in claim 14, wherein the governor is a min-max governor, and wherein: said control signal positions said throttle member such that the speed regulation of the vehicle is not mismatched with the governing action of the max-min governor.
Claim 17
Dependent Claim
45 words
An automatic speed control system as defined in claim 15, wherein the governor is an all-speed governor, and wherein: said control signal positions said throttle member such that the speed regulation of the vehicle is not mismatched with the governing action of the all-speed governor.
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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) | 1986-02-14 | 1986-08-16 | 1987-02-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-02-14 | 1990-08-16 | 1991-02-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-02-14 | 1994-08-16 | 1995-02-15 | $7700.00 | Window Closed / Lapsed |