Vehicle speed control apparatus and method

• US 8,868,312 B2
• Filed: 02/27/2013
• Issued: 10/21/2014
• Est. Priority Date: 02/27/2012
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Pedlar, Chris Edward, Connelly, Chris, Hesketh, David, Petridis, Themi Philemon
• Primary Examiner(s): Zanelli, Michael J
• Application Number:
  US13/779,534
• Publication Number:
  US 20130226420A1
• Time in Patent Office: 601 Days
• US Class Current: 701/96
• CPC Class Codes: B60K 2310/242 setting initial target speed, e.g. initial algorithms
• CPC Class Codes: B60K 31/047 the memory being digital
• CPC Class Codes: B60W 10/02 including control of driveline clutches
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 2030/1809 Without torque flow between driveshaft and engine, e.g. with clutch disengaged or transmission in neutral
• CPC Class Codes: B60W 30/00 Purposes of road vehicle drive control systems not related to the control of a particular sub-unit, e.g. of systems using conjoint control of vehicle sub-units
• CPC Class Codes: B60W 30/143 Speed control B60W30/16 takes precedence
• CPC Class Codes: B60W 30/16 Control of distance between vehicles, e.g. keeping a distance to preceding vehicle
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

The present disclosure describes systems and methods for controlling the speed of a vehicle comprising: during a pulse phase of cruise control, applying engine torque to raise speed, the amount and duration of which being responsive to engine speed; and during a glide phase of cruise control, discontinuing engine combustion. In this way cruise control may maintain a mean speed equivalent to a desired, threshold speed while reducing fuel consumption, and NVH effects felt by the end user compared to traditional cruise control methods.

Claims

1. A method of automatically controlling a speed of a vehicle, comprising:

receiving an input from a driver to enter a cruise control mode;

determining a threshold speed;

increasing the vehicle speed to a speed which is a first predetermined value above the threshold speed;

decreasing the vehicle speed to a speed which is a second predetermined value below the threshold speed; and

repeating the steps of increasing and decreasing the vehicle speed until an input is received to exit the cruise control mode; and

further comprising detecting a vehicle in front, determining a distance to the vehicle in front, maintaining the vehicle in front within a distance range to the vehicle in front and calculating the first predetermined value and the second predetermined value dependent on the distance to the vehicle in front.

2. The method as claimed in claim 1, wherein the threshold speed corresponds to a current speed of the vehicle and the threshold speed is adjustable by the driver during the cruise control mode.

3. The method as claimed in claim 1, wherein increasing the vehicle speed comprises increasing an amount of fuel supplied to an engine to cause vehicle acceleration.

4. The method as claimed in claim 1, wherein decreasing the vehicle speed comprises decreasing an amount of fuel supplied to the engine to cause vehicle deceleration.

5. The method as claimed in claim 1, wherein decreasing the vehicle speed comprises disengaging a transmission clutch of the vehicle.

6. The method as claimed in claim 1, wherein at least one of the first and the second predetermined values is selected to produce an optimal brake specific fuel consumption value from the engine.

7. The method as claimed in claim 1, wherein at least one of the first and second predetermined values is a predetermined percentage above the threshold speed.

8. The method as claimed in claim 1, further comprising reducing audio, visual or tactile phenomena associated with a repeated change in the vehicle speed.

9. The method as claimed in claim 8, further comprising reducing the audio, visual or tactile phenomena associated with the repeated change in the vehicle speed by reducing a sound produced by the engine.

10. The method as claimed in claim 8, further comprising reducing the audio, visual or tactile phenomena associated with the repeated change in the vehicle speed by varying a duty cycle of the engine.

11. The method as claimed in claims 8, further comprising reducing the audio, visual or tactile phenomena associated with the repeated change in the vehicle speed by changing the vehicle speed at a rate which is less perceptible to the driver.

12. A method of automatically controlling a speed of a vehicle, comprising:

receiving an input from a driver to enter a cruise control mode;

determining a threshold speed;

increasing the vehicle speed to a speed which is a first predetermined value above the threshold speed;

decreasing the vehicle speed to a speed which is a second predetermined value below the threshold speed;

repeating the steps of increasing and decreasing the vehicle speed until an input is received to exit the cruise control mode; and

reducing audio, visual or tactile phenomena associated with the repeated change in the vehicle speed by using a filter to alter a tachometer display.

13. The method as claimed in claim 12, further comprising detecting a vehicle in front, determining a distance to the vehicle in front, maintaining the vehicle within a distance range to the vehicle in front and calculating the first predetermined value and the second predetermined value dependent on the distance to the vehicle in front.

14. A method, comprising:

reducing noise, vibration and harshness during pulse and glide cruise control by,

filtering a tachometer output;

adjusting a rate of acceleration during a pulse phase;

varying a duty cycle of the pulse phase; and

adjusting a difference between a high speed and a low speed.

15. The method as claimed in claim 14, wherein varying the duty cycle of the pulse phase further comprises increasing a duration of fueling.

16. The method as claimed in claim 14, wherein adjusting a difference between a high speed and a low speed further comprises reducing the difference between the high speed and the low speed.