Method and system for adaptive cruise control and vehicle

Patent metadata

Field	Value
Publication number	US-2016176402-A1
Application number	US-201414909271-A
Country	US
Kind code	A1
Filing date	Aug 27, 2014
Priority date	Sep 9, 2013
Publication date	Jun 23, 2016
Grant date	—

Abstract

A method for adaptive cruise control of a host vehicle ( 2 ): A host vehicle ( 2 ) includes at least one acceleration device ( 8 ), at least one retardation device ( 10 ), a control unit ( 14 ) for acting upon the acceleration device ( 8 ) and the retardation device ( 10 ), a calculating unit ( 16 ) for determining at least one parameter related to a lead vehicle ( 6 ) and a distance sensor ( 12 ) for determining a distance from the host vehicle to the lead vehicle ( 6 ). The method includes the steps of: setting a first predetermined time distance between the host vehicle ( 2 ) and the lead vehicle ( 6 ), maintaining the first predetermined time distance, evaluating a parameter that characterizes velocity changes of the lead vehicle in order to optimize a time distance between the host vehicle ( 2 ) and the lead vehicle ( 6 ), changing the first predetermined time distance to a second predetermined time distance if the parameter that characterizes velocity changes reaches a threshold value, and maintaining the second predetermined time distance. A system, a vehicle, a computer program product and a computer program for the method are further described herein.

First claim

1 . A method for adaptive cruise control of a host vehicle ( 2 ), which host vehicle ( 2 ) comprises at least one acceleration device ( 8 ), at least one retardation device ( 10 ), a control unit ( 14 ) for acting upon the acceleration device ( 8 ) and the retardation device ( 10 ), a calculating unit ( 16 ) for determining at least one parameter related to a lead vehicle ( 6 ), and a distance sensor ( 12 ) for determining a distance to the lead vehicle ( 6 ) wherein the method comprises the steps of:
setting ( 100 ) a first predetermined time distance between the host vehicle ( 2 ) and the lead vehicle ( 6 ) in the control unit ( 14 ), and maintaining ( 102 ) the first predetermined time distance by acting upon the acceleration device ( 8 ) and the retardation device ( 10 ) by means of the control unit ( 14 ), characterized in that the method further comprises the steps of: evaluating ( 104 ), in the calculating unit ( 16 ), a parameter that characterizes velocity changes of the lead vehicle ( 6 ) while maintaining the first predetermined time distance in order to optimize a time distance between the host vehicle ( 2 ) and the lead vehicle ( 6 ), changing ( 106 ) the first predetermined time distance to a second predetermined time distance between the host vehicle ( 2 ) and the lead vehicle ( 6 ) in the control unit ( 14 ) if the parameter that characterizes velocity changes reaches a threshold value, and maintaining ( 108 ) the second predetermined time distance by acting upon the acceleration device ( 8 ) and the retardation device ( 10 ) by means of the control unit ( 14 ).

2 . A method according to claim 1 , wherein the step of changing ( 106 ) the first predetermined time distance to the second predetermined time distance comprises:
increasing ( 110 ) a time distance between the host vehicle ( 2 ) and the lead vehicle ( 6 ) in the control unit ( 14 ) if the parameter that characterizes velocity changes is above a first threshold value, so that the second predetermined time distance is longer than the first predetermined time distance.

3 . The method according to claim 2 , wherein the first and the second predetermined time distances respectively consist of a first time interval and a second time interval within which the host vehicle ( 2 ) is considered to be maintaining said respective first and second predetermined time distances, and wherein the method comprises:
activating ( 112 ) the retardation device ( 10 ) by means of the control unit ( 14 ) while maintaining the first predetermined time distance when a distance between the host vehicle ( 2 ) and the lead vehicle ( 6 ) has decreased to a predetermined portion of the first predetermined time distance, and activating ( 114 ) the retardation device ( 10 ) by means of the control unit ( 14 ) while maintaining the second predetermined time distance when a distance between the host vehicle ( 2 ) and the lead vehicle ( 6 ) has decreased to a predetermined portion of the second predetermined time distance, whereupon the control unit ( 14 ) activates the retardation device ( 10 ) to a lesser extent while maintaining said second predetermined time distance than while maintaining said first predetermined time distance.

4 . A method according to claim 1 , wherein the step of changing ( 106 ) the first predetermined time distance to the second predetermined time distance comprises:
decreasing ( 116 ) a time distance between the host vehicle ( 2 ) and the lead vehicle ( 6 ) in the control unit ( 14 ) if the parameter that characterizes velocity changes is below a second threshold value, so that the second predetermined time distance is shorter than the first predetermined time distance.

5 . The method according to any of the preceding claims, comprising the steps of:
continuing ( 118 ) to evaluate a parameter that characterizes velocity changes of the lead vehicle ( 6 ) in the calculating unit ( 16 ), and abandoning ( 120 ) a predetermined time distance between the host vehicle ( 2 ) and the lead vehicle ( 6 ) if the parameter that characterizes velocity changes is above a limit value.

6 . The method according to any of the preceding claims, wherein the parameter that characterizes velocity changes is related to a magnitude of the deviation of the lead vehicle from an average speed of the lead vehicle ( 6 ).

7 . The method according to claim 6 , wherein the parameter that characterizes velocity changes is related to a magnitude of the standard deviation of the lead vehicle from the average velocity of the lead vehicle ( 6 ).

8 . The method according to any of claims 1 - 5 , wherein the parameter that characterizes velocity changes is related to the number of deviations of the lead vehicle from an average velocity of the lead vehicle ( 6 ) per unit of time.

9 . The method according to any of claims 1 - 5 , wherein the parameter that characterizes velocity changes is related to the acceleration and retardation of the lead vehicle ( 6 ).

10 . The method according to claim 9 , wherein the parameter that characterizes velocity changes is related to how the lead vehicle ( 6 ) retards and accelerates when passing a hilltop.

11 . The method according to any of claims 1 - 5 , wherein the parameter that characterizes velocity changes is related to what vehicle type the lead vehicle ( 6 ) is.

12 . The method according to claim 11 , wherein the parameter that characterizes velocity changes is related to the slope of the roadway on which the host vehicle ( 2 ) and the lead vehicle ( 6 ) are traveling.

13 . The method according to any of the foregoing claims, wherein the parameter that characterizes velocity changes is related to the number of activations of the acceleration device ( 8 ) and/or the retardation device ( 10 ) per unit of time.

14 . A system ( 4 ) for adaptive cruise control in a host vehicle ( 2 ) comprising at least one acceleration device ( 8 ) and at least one retardation device ( 10 ), wherein the system comprises a control unit ( 14 ) for acting upon the acceleration device ( 8 ) and the retardation device ( 10 ), a calculating unit ( 16 ) for determining at least one parameter related to a lead vehicle ( 6 ) and a distance sensor ( 12 ) for determining a distance to the lead vehicle ( 6 ), and wherein the control unit ( 14 ) is arranged so as to set a first predetermined time distance between the host vehicle ( 2 ) and the lead vehicle ( 6 ) and so as to maintain the first predetermined time distance by acting upon the acceleration device ( 8 ) and the retardation device ( 10 ),
characterized in that the calculating unit ( 16 ) is arranged so as to evaluate a parameter that characterizes velocity changes of the lead vehicle ( 6 ) while maintaining the first predetermined time distance in order to optimize a time distance between the host vehicle ( 2 ) and the lead vehicle ( 6 ), wherein the control unit ( 14 ) is further arranged so as to change the first predetermined time distance to a second predetermined time distance between the host vehicle ( 2 ) and the lead vehicle ( 6 ) if the parameter that characterizes velocity changes reaches a threshold value, and so as to maintain the second predetermined time distance by acting upon the acceleration device ( 8 ) and the retardation device ( 10 ).

15 . The system ( 4 ) according to claim 14 , wherein the control unit ( 14 ) is arranged so as to increase a time distance between the host vehicle ( 2 ) and the lead vehicle ( 6 ) if the parameter that characterizes velocity changes is above a first threshold value, so that the second predetermined time distance is longer than the first predetermined time

Assignees

• Scania Cv Ab

Inventors

• Andersson Håkan
• Oremus Sebastiaan

Classifications

• B60W2554/804

  Relative longitudinal speed · CPC title

• B60W2754/30

  Longitudinal distance · CPC title

• B60W2554/801

  Lateral distance · CPC title

• B60W2710/18

  Braking system · CPC title

• B60W2710/09

  Other types of propulsion units, e.g. fluid motors, or type not specified · CPC title