Front impact mitigation system for a vehicle and method

• US 9,771,055 B1
• Filed: 11/01/2016
• Issued: 09/26/2017
• Est. Priority Date: 11/01/2016
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: Zhang, Xian, Song, Xiaofeng F., Adam, Paul A., Feldman, Dmitriy
• Primary Examiner(s): Nguyen, Cuong H
• Application Number:
  US15/340,556
• Time in Patent Office: 329 Days
• Field of Search: 701 70, 701 45, 701 96, 701301, 180274-275, 340436
• CPC Class Codes: B60T 2201/00 Particular use of vehicle brake systems; Special systems using also the brakes; Special software modules within the brake system controller
• CPC Class Codes: B60T 2201/024 Collision mitigation systems
• CPC Class Codes: B60T 2250/04 Vehicle reference speed; Vehicle body speed
• 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: B60T 8/174 characterised by using special control logic, e.g. fuzzy logic , neural computing
• CPC Class Codes: B60T 8/17558 specially adapted for collision avoidance or collision mitigation road vehicle drive control systems for collision avoidance otherwise than by controlling a particular sub-unit B60W30/09
• CPC Class Codes: B60W 2520/10 Longitudinal speed
• CPC Class Codes: B60W 30/09 Taking automatic action to avoid collision, e.g. braking and steering
• CPC Class Codes: B60W 40/10 related to vehicle motion
• CPC Class Codes: G01S 13/50 Systems of measurement based on relative movement of target
• CPC Class Codes: G01S 13/87 Combinations of radar systems, e.g. primary radar and secondary radar
• CPC Class Codes: G01S 13/931 of land vehicles
• CPC Class Codes: G01S 15/50 Systems of measurement, based on relative movement of the target
• CPC Class Codes: G01S 15/87 Combinations of sonar systems
• CPC Class Codes: G01S 15/931 of land vehicles
• CPC Class Codes: G01S 17/50 Systems of measurement based on relative movement of target
• CPC Class Codes: G01S 17/87 Combinations of systems using electromagnetic waves other than radio waves
• CPC Class Codes: G01S 17/931 of land vehicles
• CPC Class Codes: G01S 2013/932 using own vehicle data, e.g. ground speed, steering wheel direction
• CPC Class Codes: G01S 2013/9323 Alternative operation using light waves
• CPC Class Codes: G01S 2013/9324 : Alternative operation using ultrasonic waves
• CPC Class Codes: G01S 2013/93271 : in the front of the vehicles
• CPC Class Codes: G01S 2013/93272 : in the back of the vehicles
• CPC Class Codes: G01S 2013/93274 : on the side of the vehicles
• CPC Class Codes: G01S 2015/937 : sensor installation details constructional features of transducers G01S7/521 and B06B; casing of transducers, e.g. housing, cover or filler details, G10K9/22; mounting of transducers, i.e. fixture, fitting or holder details, G10K11/004

Abstract

A front impact mitigation system for a host vehicle and a method for operating a front impact mitigation system. The front impact mitigation system can take into account the position of a rear object that trails the host vehicle to develop a modified front impact mitigation control signal that at least partially mitigates the likelihood of certain rear impact collisions between the rear object and the host vehicle when the host vehicle is responding to the presence of an impending leading obstacle. A modified front impact mitigation control signal may be developed to account for the speed of the host vehicle and the distance that the rear object trails the host vehicle.

Claims

1. A method for operating a front impact mitigation system of a host vehicle, comprising the steps of:

receiving a host vehicle speed signal at a control unit that is representative of a host vehicle speed;

receiving a rear object distance signal at the control unit that is representative of a distance that a rear object trails the host vehicle; and

using the host vehicle speed signal and the rear object distance signal to develop a modified front impact mitigation control signal at the control unit, wherein the modified front impact mitigation control signal is modified from a standard front impact mitigation control signal to at least partially mitigate a likelihood of a significant rear impact collision at the host vehicle by the rear object during operation of the front impact mitigation system.

2. The method of claim 1, further comprising the step of determining a deceleration adjustment parameter based on the host vehicle speed and the distance that the rear object trails the host vehicle.

3. The method of claim 2, further comprising the step of adjusting a maximum level deceleration of a crash imminent braking feature of the front impact mitigation system using the deceleration adjustment parameter to obtain an adjusted deceleration value.

4. The method of claim 3, further comprising using the adjusted deceleration value to calculate a modified time-to-collision value to be used as the modified front impact mitigation control signal.

5. The method of claim 4, wherein the modified time-to-collision value is less than the standard time-to-collision value.

6. The method of claim 2, wherein the deceleration adjustment parameter is determined by using data from an optimization graph which compares the host vehicle speed and the distance that the rear object trails the host vehicle.

7. The method of claim 1, further comprising the step of comparing the modified front impact mitigation control signal to the standard front impact mitigation control signal.

8. The method of claim 7, wherein the modified front impact mitigation control signal is used to control one or more aspects of the front impact mitigation system when the modified front impact control signal at least partially mitigates a likelihood of a significant rear impact collision at the host vehicle by the rear object.

9. The method of claim 8, wherein the modified front impact mitigation control signal is used to control a crash imminent braking feature of the front impact mitigation system.

10. The method of claim 9, wherein the modified front impact mitigation control signal causes a braking unit to decelerate the vehicle at a slower rate.

11. The method of claim 1, wherein a significant rear impact collision is defined by a rear collision speed between the rear object and the host vehicle between 5 m/s and 15 m/s, inclusive.

12. The method of claim 11, wherein the host vehicle determines whether the rear object has one or more imminent steering options to confirm the significant rear impact collision.

13. The method of claim 12, wherein the standard front impact control signal is used to control one or more aspects of the front impact mitigation system when the rear object has one or more imminent steering options.

14. A front impact mitigation system for a host vehicle, comprising:

a host vehicle speed sensor configured to determine a host vehicle speed;

an object detection sensor configured to determine a distance that a rear object trails the host vehicle; and

a control unit coupled to the host vehicle speed sensor and the object detection sensor and configured to develop a modified front impact mitigation control signal based at least partially on the host vehicle speed and the distance that the rear object trails the host vehicle, wherein the modified front impact mitigation control signal is modified from a standard front impact control signal to at least partially mitigate a likelihood of a significant rear impact collision at the host vehicle by the rear object during operation of the front impact mitigation system.