Adaptive cruise control system

• US 8,396,642 B2
• Filed: 12/19/2008
• Issued: 03/12/2013
• Est. Priority Date: 03/18/2008
• Status: Active Grant

• Current Assignee: ZF CV Systems Europe BV
• Original Assignee: Wabco GmbH (Wabco Holdings Incorporated)
• Inventors: Breuer, Karsten
• Primary Examiner(s): Chen, Shelley
• Application Number:
  US12/736,168
• Publication Number:
  US 20110040467A1
• Time in Patent Office: 1,544 Days
• Field of Search: 701/96
• US Class Current: 701/96
• CPC Class Codes: B60T 7/22 initiated by contact of vehicle, e.g. bumper, with an external object, e.g. another vehicle , or by means of contactless obstacle detectors mounted on the vehicle
• CPC Class Codes: B60W 10/04 including control of propulsion units
• CPC Class Codes: B60W 10/18 including control of braking systems
• CPC Class Codes: B60W 2050/0083 Setting, resetting, calibration
• CPC Class Codes: B60W 2510/184 Brake temperature, e.g. of fluid, pads or discs
• CPC Class Codes: B60W 2552/40 Coefficient of friction
• CPC Class Codes: B60W 2720/106 Longitudinal acceleration
• CPC Class Codes: B60W 30/095 Predicting travel path or likelihood of collision
• CPC Class Codes: B60W 30/16 Control of distance between vehicles, e.g. keeping a distance to preceding vehicle
• CPC Class Codes: B60W 50/14 Means for informing the driver, warning the driver or prompting a driver intervention

Abstract

An adaptive cruise control system for a motor vehicle includes a service brake comprising an electronic controller programmed/configured to detect driving data of the vehicle and distance data to a preceding vehicle, to calculate a movement prediction based on the driving and distance data, to influence the movement of the vehicle by influencing driving and braking, and to output a warning signal to the vehicle driver if the prediction indicates that, assuming a predetermined limiting braking retardation, a probability of an impact with another vehicle, with the adaptive cruise control system being activated, exceeds a predetermined impact probability threshold value without any intervention on the part of the driver. The controller is configured to detect braking parameters, based on which a maximum braking retardation that can be achieved with the service brakes can be calculated, and to reduce the limiting retardation, if the maximum retardation is below a predetermined value.

Claims

1. A headway regulated cruise control system for a motor vehicle having a braking system including a service brake, the system comprising an electronic controller is suitably programmed to

detect driving data of the motor vehicle and distance data with respect to a preceding vehicle,

calculate a motion prediction from the driving data and the distance data,

influence the state of motion of the motor vehicle by influencing one of driving and braking system devices,

output a warning signal to a driver of the motor vehicle when the motion prediction indicates that, with a predetermined limiting retardation, with the headway regulated cruise controller activated and without driver intervention, a probability of collision with the preceding vehicle that exceeds a predetermined collision probability threshold value,

detect braking parameters for calculating a maximum braking retardation that can be achieved with the service brakes, and

reduce the limiting retardation when the maximum braking retardation is below a predetermined retardation threshold value.

2. The headway regulated cruise control system as claimed in claim 1, wherein the retardation threshold value is the limiting retardation.

3. The headway regulated cruise control system as claimed in claim 1, wherein the electronic controller is suitably programmed to reduce the limiting retardation to a product of the maximum braking retardation with a safety factor.

4. The headway regulated cruise control system as claimed in claim 1, wherein the braking parameter is at least one of a temperature of the service brakes and a maximum torque applicable to a wheel of the vehicle detected by a closed-loop anti-slip controller.

5. The headway regulated cruise control system as claimed in claim 4, wherein the electronic controller is suitably programmed to extract the braking parameters from an EBC5 message transmitted by the braking system via a data bus of the motor vehicle.

6. The headway regulated cruise control system as claimed in claim 1, wherein electronic controller is suitably programmed to:

detect whether an anti-lock system of the motor vehicle has been active for the purpose of controlling the service brake within a predetermined time interval, and

when the anti-lock system has been active within the predetermined time interval, detect the braking retardation achieved by the anti-lock system and determine the maximum braking retardation from the braking retardation achieved.

7. The headway regulated cruise controly system as claimed in claim 6, wherein the electronic controller is suitably programmed to:

detect whether the anti-lock system is currently controlling the service brake,

when the anti-lock system is controlling the service brake, detect the maximum instantaneously achievable braking retardation by the anti-lock system, and

determine the limiting retardation from the instantaneously achieved braking retardation.

8. The headway regulated cruise control system as claimed in claim 7, wherein the electronic controller is suitably programmed to:

extract an “

ABS control active”

signal from an EBC1 message transmitted by the anti-lock system via a data bus of the motor vehicle, and

determine the braking parameter from a retardation determined one of (i) by at least one of linear vehicle and wheel speeds and (ii) from a braking retardation detected directly by a sensor.

9. A motor vehicle having a headway regulated cruise control system as claimed in claim 1.

10. A method for effecting headway regulated cruise control in a motor vehicle, the method comprising the steps of:

(a) detecting driving data of the motor vehicle and distance data with respect to a preceding vehicle,

(b) calculating a motion prediction from the driving data and the distance data

(c) influencing the state of motion of the motor vehicle by influencing at least one of driving and braking devices, and

(d) outputting a warning signal to a driver of the motor vehicle when the motion prediction indicates that, with a predetermined limiting retardation, a collision probability of a collision with the preceding vehicle exceeds a predetermined collision probability threshold value,

(e) calculating a maximum achievable braking retardation from braking parameters of the service brakes, and

(f) reducing the limiting retardation when the maximum braking retardation is below a predetermined retardation threshold value.

11. The method as claimed in claim 10, further comprising the step of continuously repeating steps (a)-(f).

12. A headway regulated cruise controller suitably programmed to effect the method steps according to claim 10.