METHOD AND SYSTEM FOR CONTROLLING A VEHICLE CRUISE CONTROL

• US 20130030668A1
• Filed: 07/02/2009
• Published: 01/31/2013
• Est. Priority Date: 07/02/2009
• Status: Active Grant

• Current Assignee: Volvo Lastvagnar AB (Volvo AB)
• Original Assignee: Volvo Lastvagnar AB (Volvo AB)
• Inventors: Eriksson, Anders, Bjernetun, Johan
• Granted Patent: US 9,096,229 B2
• Time in Patent Office: Days
• US Class Current: 701/94
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/11 Stepped gearings
• CPC Class Codes: B60W 2552/20 Road profile, i.e. the change in elevation or curvature of a plurality of continuous road segments
• CPC Class Codes: B60W 2556/50 of positioning data, e.g. GPS [Global Positioning System] data
• CPC Class Codes: B60W 2720/103 Speed profile
• CPC Class Codes: B60W 30/143 Speed control B60W30/16 takes precedence
• CPC Class Codes: B60W 50/0097 Predicting future conditions

Abstract

A method and a vehicle cruise control system performing the steps of driving with the cruise control active and set to maintain a set target speed, registering a first position when driving in an uphill slope of a hill where vehicle retardation has decreased vehicle speed to a first speed below the set target speed and where the retardation has decreased to zero or acceleration has just started in order to increase speed to the set target speed, registering a desired speed in a second position downhill of the crest at a first distance after the crest, based on the desired speed calculating a minimum speed at the crest with which the vehicle has to pass the crest in order to be able to reach the desired speed with zero fuel consumption during the first distance, controlling speed between the first position and the crest so that the vehicle reaches the minimum speed when passing the crest.

Claims

1. Method for controlling a vehicle cruise control comprising the steps of:

driving the vehicle with the cruise control active and set to maintain a vehicle set target speed;

registering a first vehicle position when driving in an uphill slope of a hill where vehicle retardation has decreased vehicle speed to a first vehicle speed below the vehicle set target speed and where the retardation has decreased to zero or the vehicle has just started to accelerate in order to increase vehicle speed to the vehicle set target speed;

registering a desired vehicle speed in a second position downhill of a crest of the hill at a first distance after the crest;

based on the desired vehicle speed calculating a minimum vehicle speed at the crest with which the vehicle has to pass the crest in order to be able to reach the desired vehicle speed with a minimized or zero fuel consumption during the first distance;

controlling vehicle speed during a second distance between the first vehicle position and the crest so that the vehicle reaches the minimum vehicle speed when passing the crest, and maintaining a vehicle speed below the vehicle set target speed during the second distance.

2. The method as claimed in claim 1, wherein the second vehicle position is one of;

a predetermined vehicle traveling time from the crest,

a predetermined distance from the crest,

at the end of the downhill,

at a distance from the crest where a vehicle traveling resistance is estimated to change from negative to positive.

3. The method as claimed in claim 1, comprising the step of calculating a needed vehicle acceleration or retardation during the second distance in order to reach the minimum vehicle speed at the crest with a minimized fuel consumption during the second distance.

4. The method as claimed in the claim 1, comprising the step of:

registering the first vehicle speed being just below a direct gear engagement vehicle speed at the first vehicle position;

when having registered a predetermined vehicle condition setting the minimum vehicle speed to equal the direct gear engagement vehicle speed and accelerating the vehicle up to the minimum vehicle speed and engaging a direct gear;

driving the vehicle with the direct gear engaged during remaining part of the second distance.

5. The method as claimed in claim 4, wherein the predetermined vehicle condition comprising at least one of:

the just below a direct gear engagement vehicle speed meaning a speed difference below 5 km/h between the direct gear engagement vehicle speed and the first vehicle speed;

the second distance is greater than a predetermined value;

an estimated time interval for driving the vehicle with the direct gear engaged during the second distance is greater than a predetermined value.

6. The method as claimed in claim 1, comprising setting a maximum vehicle over speed for the vehicle cruise control, and where the maximum vehicle over speed is at least equal to or higher than the vehicle set target speed, and where the desired vehicle speed equals the maximum vehicle over speed.

7. The method as claimed in claim 1, comprising setting a minimum vehicle under speed, having a predetermined relation to the vehicle set target speed.

8. The method as claimed in claim 7, wherein the predetermined relation is one of:

the minimum vehicle under speed is a predetermined percentage of the vehicle set target speed;

the minimum vehicle under speed is a predetermined amount below the vehicle set target speed.

9. The method as claimed in claim 1, wherein with information about present vehicle position and coming road topography of the hill predicting the crest, the second position and the minimum vehicle speed.

11. A vehicle cruise control system comprising a control unit, driver input interface, vehicle position identifying device, road topography identifying device, wherein the control unit is arranged to perform method steps of claim 1 use information from the vehicle position identifying device and the road topography identifying device in order to calculate the minimum vehicle speed.

12. A computer comprising program code for performing the method of claim 1.

13. A non-transitory computer readable medium comprising program code means for performing. the method of claim 1 said the program.

14. A non-transitory data storage medium comprising a computer readable program code to perform the method of claim 1.

10. The method as claimed in wherein if the second distance is shorter than a predetermined value, then the minimum vehicle speed is set to be equal to the first vehicle speed.