Patent US4924397A successfully refreshed from Google Patents.
US4924397A
Expired / Lapsed
US
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Vehicle cruise control system
Assignee: Honda Motor Co Ltd
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Filing: 1987-12-07
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Granted: 1990-05-08
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Expires: 2007-12-07
Abstract
Abstract A vehicle cruise control system, comprising a control circuit for producing a control signal for maintaining a speed of a vehicle at a fixed level according to a difference between an actual vehicle speed and a target vehicle speed, and a drive circuit for producing a drive signal for selectively driving an actuator in a direction either to accelerate the vehicle or to decelerate the vehicle according to the control signal from the control circuit. The drive circuit is provided with a transistor bridge circuit comprising four drive transistors for producing the drive signal. The control circuit is provided with a detection means for detecting an abnormal state of the system and an inhibiting means which brings at least one of the drive transistors into an non-conductive state when any abnormal state is detected by the detecting means. The control circuit may be programmed to perform a certain diagnostic procedure for testing the soundness of the drive transistors. Thus, erratic behavior of the cruise control system and destruction of the drive transistors can be effectively prevented.
Inventors
- 👤 Norimitsu Kurihara
- 👤 Masahiko Asakura
- 👤 Mitsuru Matsui
- 👤 Yasuhiko Otsuka
- 👤 Kazuhiko Tachikawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 12:18
CPC Classifications
B; B60; B60K; B60K31/00; B60K31/02; B60K31/04; B60K31/042; B60K31/045; B60K31/047; B60W; B60W50/00; B60W50/02; B60W50/0205; B60W2050/021
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
158 words
A vehicle cruise control system, comprising: a control circuit for producing a control signal for maintaining a speed of a vehicle at a fixed level according to a difference between an actual vehicle speed and a target vehicle speed; and a drive circuit for producing a drive signal for selectively driving an actuator in a direction either to accelerate the vehicle or to decelerate the vehicle according to the control signal from the control circuit, wherein: the drive circuit is provided with a transistor bridge circuit comprising four drive transistors for producing the drive signal; and the control circuit is provided with a detecting means for detecting an abnormal control signal and for detecting an abnormal drive signal, and an inhibiting means which switches at least one of the drive transistors into a nonconductive state when any abnormal control signal is detected by the detecting means and when any abnormal drive signal is detecting by the detecting means.
Claim 2
Dependent Claim
158 words
A vehicle cruise control system, comprising: a control circuit for producing a control signal for maintaining a speed of a vehicle at a fixed level according to a difference between an actual vehicle speed and a target vehicle speed; and a drive circuit for producing a drive signal for selectively driving an actuator in a direction either to accelerate the vehicle or to decelerate the vehicle according to the control signal from the control circuit, wherein: the drive circuit is provided with a transistor bridge circuit comprising four drive transistors for producing the drive signal; and the control circuit is provided with a detecting means for detecting an abnormal control signal and for detecting an abnormal drive signal, and an inhibiting means which switches at least one of the drive transistors into a nonconductive state when any abnormal control signal is detected by the detecting means and when any abnormal drive signal is detecting by the detecting means.
Claim 3
Dependent Claim
71 words
A vehicle cruise control system as defined in claim 1, wherein the inhibiting means at one time switches into conductive states the transistors in a first path in the bridge for driving the actuator in the direction to accelerate the vehicle and at a second time switches into conductive states the other transistors in a second path in the bridge for driving the actuator in the direction to decelerate the vehicle.
Claim 4
Dependent Claim
77 words
A vehicle cruise control system as defined in claim 1, wherein the inhibiting means at one time switches into nonconductive state at least one of the transistors in a first path in the bridge for driving the actuator in the direction to accelerate and at a second time switches into a conductive state at least one of the transistors in a second path in the bridge for driving the actuator in the direction to decelerate the vehicle.
Claim 5
Dependent Claim
37 words
A vehicle cruise control system as defined in claim 1, wherein the control circuit comprises a micro processor and the detection means comprises a circuit which monitors for abnormal signals at an output of the micro processor.
Claim 6
Dependent Claim
38 words
A vehicle cruise control system as defined in claim 1, wherein the detector means comprises a circuit connected to at least one of the drive transistors for monitoring the state of at least one of the drive transistors.
Claim 7
Dependent Claim
58 words
A vehicle cruise control system as defined in claim 1, wherein a brake switch is interposed in a first power line leading to one of the transistors located in a first path for accelerating the vehicle, and one of the transistors located in a second path for decelerating the vehicle is directly connected to a second power line.
Claim 8
Dependent Claim
31 words
A vehicle cruise control system as defined in claim 1, wherein the drive circuit further comprises a transistor for controlling an electromagnetic clutch interposed in output shaft means of the actuator.
Claim 9
Dependent Claim
37 words
A vehicle cruise control system as defined in claim 7, wherein a brake switch which opens upon pressing of a brake pedal is interposed in a power line leading to the transistor for controlling the electromagnetic clutch.
Claim 10
Dependent Claim
111 words
A vehicle cruise control system as defined in claim 7 wherein: the actuator comprises a limit switch for indicating a limit of a stroke of the output shaft means of the actuator in a direction to decelerate the vehicle; and the detection means disconnects the electromagnetic clutch when it has detected that the limit of the stroke of the output shaft means of the actuator in a direction to decelerate the vehicle has been reached and that a drive signal to decelerate the vehicle is being produced from the control circuit, and connects the electromagnetic clutch when it has thereafter detected that a drive signal to accelerate the vehicle is produced.
Claim 11
Dependent Claim
43 words
A vehicle cruise control system a defined in claim 9, wherein the control circuit supplies a drive signal for accelerating the vehicle to the drive circuit when the detection means reconnects the electromagnetic clutch after the detection means has disconnected the electromagnetic clutch.
Claim 12
Dependent Claim
149 words
A vehicle cruise control system comprising: a control circuit for producing a control signal for maintaining a speed of a vehicle at a fixed level according to a difference between an actual vehicle speed and a target vehicle speed; and a drive circuit for producing a drive signal for selectively driving an actuator in a direction either to accelerate the vehicle or to decelerate the vehicle according to the control signal from the control circuit; wherein: the drive circuit comprises an acceleration drive circuit and a direction drive circuit; and the acceleration drive circuit is connected to a first power line by way of a brake switch which opens upon pressing of a brake pedal while the deceleration drive circuit is directly connected to a second power line; wherein the drive control further comprises a transistor for controlling an electromagnetic clutch interposed in an output shaft of the actuator.
Claim 13
Dependent Claim
149 words
A vehicle cruise control system comprising: a control circuit for producing a control signal for maintaining a speed of a vehicle at a fixed level according to a difference between an actual vehicle speed and a target vehicle speed; and a drive circuit for producing a drive signal for selectively driving an actuator in a direction either to accelerate the vehicle or to decelerate the vehicle according to the control signal from the control circuit; wherein: the drive circuit comprises an acceleration drive circuit and a direction drive circuit; and the acceleration drive circuit is connected to a first power line by way of a brake switch which opens upon pressing of a brake pedal while the deceleration drive circuit is directly connected to a second power line; wherein the drive control further comprises a transistor for controlling an electromagnetic clutch interposed in an output shaft of the actuator.
Claim 14
Dependent Claim
31 words
A vehicle cruise control system as defined in claim 11, wherein the transistor for controlling the electromagnetic clutch is connected to the first power line by way of the brake switch.
Claim 15
Independent Claim
212 words
A method of diagnosing drive transistors in a vehicle cruise control system comprising: a control circuit for producing a control signal for maintaining a speed of a vehicle at a fixed level according to a difference between an actual vehicle speed and a target vehicle speed; an electric actuator for driving a vehicle speed control means either to accelerate or to decelerate a vehicle; an electromagnetic clutch interposed in an output shaft of the actuator; and a drive circuit comprising a transistor bridge circuit having four drive transistors for controlling the actuator and a drive transistor for controlling the electromagnetic clutch, the drive circuit producing a drive signal for selectively driving the actuator in a direction either to accelerate the vehicle or to decelerate the electromagnetic clutch according to the control signal from the control circuit; comprising the steps of: the control circuit sending a signal to switch to a conductive state one of the drive transistors; and testing the capability to be in a nonconductive state of a transistor which is connected in series with the drive transistor which has been switched to a conductive state after a power switch to the vehicle cruise control system is turned on and before a set switch for initiating a cruise control is activated.
Claim 16
Independent Claim
212 words
A method of diagnosing drive transistors in a vehicle cruise control system comprising: a control circuit for producing a control signal for maintaining a speed of a vehicle at a fixed level according to a difference between an actual vehicle speed and a target vehicle speed; an electric actuator for driving a vehicle speed control means either to accelerate or to decelerate a vehicle; an electromagnetic clutch interposed in an output shaft of the actuator; and a drive circuit comprising a transistor bridge circuit having four drive transistors for controlling the actuator and a drive transistor for controlling the electromagnetic clutch, the drive circuit producing a drive signal for selectively driving the actuator in a direction either to accelerate the vehicle or to decelerate the electromagnetic clutch according to the control signal from the control circuit; comprising the steps of: the control circuit sending a signal to switch to a conductive state one of the drive transistors; and testing the capability to be in a nonconductive state of a transistor which is connected in series with the drive transistor which has been switched to a conductive state after a power switch to the vehicle cruise control system is turned on and before a set switch for initiating a cruise control is activated.
Claim 17
Dependent Claim
92 words
A method of diagnosing drive transistors in a vehicle cruise control system as defined in claim 13, further comprising the steps of: testing the capability to be in a nonconductive state of the transistor for driving the electromagnetic clutch by detecting electric current conducted by said transistor after the set switch is activated and before the electromagnetic clutch is connected; and testing the capability to be in a conductive state of the transistor for driving the electromagnetic clutch by detecting electric current conducted by the transistor after the electromagnetic clutch is connected.
Claim 18
Dependent Claim
90 words
A method of diagnosing drive, transistors in a vehicle cruise control system as defined in claim 13, further comprising the steps of: sending a drive signal for accelerating the vehicle from the control circuit to the transistor bridge circuit to take up any slack in a linkage between the output shaft means of the actuator and the vehicle speed control means immediately after the electromagnetic clutch is connected; and testing the capability to be in a nonconductive state of the drive transistors located in a path for accelerating the vehicle.
Claim 19
Dependent Claim
74 words
A method of diagnosing drive transistors in a vehicle cruise control system as defined in claim 13, further comprising the steps of: sending a deceleration signal from the control circuit to the transistor bridge circuit after a set switch for initiating a cruise control is activated and before the electromagnetic clutch is connected; and testing the capability to be in a conductive state of the drive transistors in a path for accelerating the vehicle.
Claim 20
Dependent Claim
69 words
A method of diagnosing drive transistors in a vehicle cruise control system as defined in claim 14, further comprising the steps of: sending an acceleration signal from the control circuit to the transistor bridge circuit after a set switch is activated and before the electromagnetic clutch is connected; and testing the capability to be in a conductive state of the drive transistors in a path for decelerating the vehicle.
References Cited (Backward Citations)
US4273208A
Cited
US4380799A
Cited
US4394739A
Cited
US4434469A
Cited
US4451890A
Cited
US4451888A
Cited
JPS57119682A
Cited
US4539642A
Cited
US4540060A
Cited
US4524893A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-05-07 | 1993-11-06 | 1994-05-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-05-07 | 1997-11-06 | 1998-05-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-05-07 | 2001-11-06 | 2002-05-08 | $7700.00 | Window Closed / Lapsed |