Vehicle cruise control device and method

• US 20040040765A1
• Filed: 03/13/2003
• Published: 03/04/2004
• Est. Priority Date: 08/30/2002
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Satou, Shinya, Hori, Toshio
• Granted Patent: US 7,308,961 B2
• Time in Patent Office: Days
• US Class Current: 180/170
• CPC Class Codes: B60K 31/04 and means for comparing one electrical quantity, e.g. voltage, pulse, waveform, flux, or the like, with another quantity of a like kind, which comparison means is involved in the development of an electrical signal which is fed into the controlling means
• CPC Class Codes: B60W 2050/001 Proportional integral [PI] controller
• CPC Class Codes: B60W 2050/0022 Gains, weighting coefficients or weighting functions
• CPC Class Codes: B60W 2540/12 Brake pedal position
• CPC Class Codes: B60W 2554/00 Input parameters relating to objects
• CPC Class Codes: B60W 2554/801 Lateral distance
• CPC Class Codes: B60W 2554/802 Longitudinal distance
• CPC Class Codes: B60W 2555/20 Ambient conditions, e.g. wind or rain
• CPC Class Codes: B60W 2710/0605 Throttle position
• CPC Class Codes: B60W 2720/106 Longitudinal acceleration
• CPC Class Codes: F02D 11/105 characterised by the function converting demand to actuation, e.g. a map indicating relations between an accelerator pedal position and throttle valve opening or target engine torque
• CPC Class Codes: F02D 2200/501 Vehicle speed
• CPC Class Codes: F02D 31/002 controlling air supply

Abstract

A maximum permissible acceleration is calculated so as to take into account vehicle stability, driver'"'"'s comfort, road surface information and traffic information, driver'"'"'s specific taste in acceleration and deceleration, and the like. An acceleration limiting process is carried out, in which a feedback gain in vehicle speed feedback control is corrected as may be necessary based on a relationship between the maximum permissible acceleration and actual acceleration information so as to keep the actual acceleration within the maximum permissible acceleration. The present invention thereby makes it possible to control a vehicle speed within a desired acceleration range even under conditions, in which there is a large vehicle speed deviation as in a resume mode, causing an excessively large acceleration or deceleration to tend to occur. Auto cruise control offering an outstanding safety and comfort can thus be implemented.

Claims

1. A vehicle cruise control device for controlling a throttle opening in accordance with a deviation between a set target vehicle speed and an actual vehicle speed, wherein reference acceleration in a segment of acceleration is set in advance and, based on said reference acceleration and actual acceleration, a limiting process that limits said throttle opening is performed in calculation of the throttle opening.

2. The vehicle cruise control device according to claim 1, wherein said limiting process performed in the calculation of the throttle opening is accomplished through adjusting a vehicle speed feedback gain.

3. The vehicle cruise control device according to claim 2, wherein said adjustment of the vehicle speed feedback gain is applied to a feedback gain of an integral controller.

4. The vehicle cruise control device according to claim 1, wherein said reference acceleration is calculated based on driver'"'"'s comfort and vehicle stability, road surface condition, information on the driver'"'"'s accelerator operation, and traffic information.

5. The vehicle cruise control device according to claim 1, wherein said limiting process is performed so as to ensure that said actual acceleration does not exceed said reference acceleration.

6. A vehicle cruise control device for controlling a throttle opening in accordance with a deviation between a set target vehicle speed and an actual vehicle speed, wherein either a vehicle speed feedback control or an acceleration feedback control is selected according to a running condition.

7. The vehicle cruise control device according to claim 6, wherein said acceleration feedback control is selected after a brake has been operated and, after the lapse of a predetermined period of time, said vehicle speed feedback control is selected.

8. The vehicle cruise control device according to claim 6, wherein said selection of the vehicle speed feedback control or the acceleration feedback control is made so as to ensure that said actual vehicle speed does not exceed said target vehicle speed.

9. The vehicle cruise control device according to claim 6, wherein said acceleration feedback control is provided for a resume period after said vehicle speed feedback control has been canceled.

10. The vehicle cruise control device according to claim 6, wherein said acceleration feedback control is selected after said vehicle speed feedback control has been canceled.

11. The vehicle cruise control device according to claim 6, wherein said vehicle speed feedback control or said acceleration feedback control is selected depending on the smaller of deviations from a control variable for said vehicle speed feedback control and from a control variable for said acceleration feedback control.

12. A vehicle cruise control method, comprising the steps of:

inputting a sensor signal or a cruise control signal;

calculating a condition for a cruise control;

calculating a target vehicle speed based on said condition for the cruise control;

calculating a maximum permissible acceleration based on said cruise control condition;

calculating a target throttle opening based on said maximum permissible acceleration; and

controlling a vehicle speed in accordance with said target throttle opening.

13. The vehicle cruise control method according to claim 12, wherein said target throttle opening is calculated by calculating an actual acceleration using said sensor signal, calculating an amount of correction for a vehicle speed feedback gain using an acceleration deviation between said maximum permissible acceleration and said actual acceleration, calculating a vehicle speed deviation between said target vehicle speed and said actual vehicle speed, and calculating said vehicle speed feedback gain based on said vehicle speed deviation and said amount of correction.