Vehicle pre-crash sensing based conic target threat assessment system

• US 6,801,843 B2
• Filed: 05/24/2002
• Issued: 10/05/2004
• Est. Priority Date: 05/24/2002
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Prakah-Asante, Kwaku O., Rao, Manoharprasad K., Strumolo, Gary Steven
• Primary Examiner(s): Beaulieu, Yonel
• Application Number:
  US10/155,627
• Publication Number:
  US 20030220728A1
• Time in Patent Office: 865 Days
• Field of Search: 707/45, 707/46, 707/47, 707/96, 707/301, 342/70, 342/72, 342/113, 342/114, 340/901, 340/903, 340/425.5, 340/435, 340/436, 180/170, 280/734
• US Class Current: 701/45
• CPC Class Codes: B60R 21/013 including means for detecting collisions, impending collisions or roll-over
• CPC Class Codes: B60R 21/0132 responsive to vehicle motion parameters , e.g. to vehicle longitudinal or transversal deceleration or speed value
• CPC Class Codes: B60R 21/0134 responsive to imminent contact with an obstacle , e.g. using radar systems
• CPC Class Codes: G01S 13/723 by using numerical data
• CPC Class Codes: G01S 2013/932 using own vehicle data, e.g. ground speed, steering wheel direction
• CPC Class Codes: G08G 1/165 for passive traffic, e.g. including static obstacles, trees
• CPC Class Codes: G08G 1/166 for active traffic, e.g. moving vehicles, pedestrians, bikes

Abstract

A pre-crash assessment system includes a host vehicle in motion. A remote sensor, status monitoring sensors, and safety device actuators are coupled to the host object. The remote sensor detects target object dynamics. The status monitoring sensors detect host object dynamics. The safety device actuators activate safety devices. A threshold for each safety device actuator is defined by a safety device activation specification. A safety device controller generates tracking signals based on host object and target object dynamics by generalized conic curve fitting techniques. The safety device controller also estimates future positions of the host and target objects, and estimates whether the potential for crash between the host and target objects is within the threshold criteria for specific safety device actuation.

Claims

1. A pre-crash assessment system for a host vehicle in motion with a first target object in a near zone of the host vehicle, comprising:

a remote sensor coupled to the host vehicle for detecting a first target object dynamic data set comprising a plurality of first target object coordinates with respect to said host vehicle;

a status monitoring sensor coupled to the host vehicle for detecting a host vehicle dynamic data set comprising a plurality of host vehicle coordinates;

a safety device actuator, coupled to the host vehicle, for activating a safety device, said safety device actuator having a threshold response time; and

a safety device controller, coupled to the host vehicle for generating a threshold criteria assessment based on said host vehicle dynawic data set and said first target object dynamic data set, said controller estimating future positions of the host vehicle and the first target object by fitting a generalized conic curve to said first target object dynamic data set, said controller further estimating whether a potential for impact between the host vehicle and the first target object is within said threshold response time for said safety device actuator, and

wherein said generalized conic curve is of the form;

2. The system of claim 1 wherein said first target object data set comprises at least five data points.

3. The system of claim 1 wherein said future positions of said first target object are determined by normalizing the generalized conic curve with A+C=1 to resolve values for A, B, C, D, E and F.

4. The system of claim 1, further comprising multiple target objects in the near zone of the host vehicle.

5. The system of claim 1 wherein said remote sensor comprises a radar sensing system, a lidar sensor or a vision sensor.

6. The system of claim 1 wherein said safety device comprises an airbag or a motorized safety belt pretensioner.

7. A pre-crash assessment system, having a first target object in a near zone of a host object in motion, comprising:

a remote sensor coupled to the host object for detecting a first target object dynamic;

a status monitoring sensor coupled to the host object for detecting a host object dynamic;

a first safety device actuator, coupled to the host object, for activating a first safety device;

a first safety device activation specification defining a first threshold response time for said first safety device actuator; and

a safety device controller, coupled to the host object for generating a threshold criteria assessment based on said host object dynamic and said first target object dynamic, said controller estimating future positions of the host object and the first target object by fitting a generalized conic curve to said first target object dynamic, said controller further estimating whether a potential for crash between the host object and the first target object is within said first threshold response time for said first safety device actuator, said safety device controller further controlling said first safety device actuator in response to said threshold criteria assessment, and

wherein said generalized conic curve is of the form;

8. The system claim 7 further of comprising multiple target objects in the near zone of the host object.

9. The system of claim 7 wherein said first safety device comprises an airbag or a motorized safety belt pretensioner.

10. The system of claim 7 wherein said remote sensor comprises a radar sensing system, a lidar sensor or a vision sensor.

11. The system of claim 7 further comprising a second safety device actuator, coupled to the host vehicle, for activating a second safety device, and a second safety device activation specification defining a second threshold response time for said second safety device actuator, and wherein said safety device controller further estimates whether said potential for impact between the host vehicle and the first target vehicle is within said second threshold response time for said second safety device actuator, thereby defining a second threshold assessment, said safety device controller further controlling said second safety device actuator in response to said second threshold assessment.

12. The system of claim 7 wherein said first target object data set comprises at least five data points.

13. A method for pre-crash threat assessment for a host vehicle in motion, comprising:

sensing a first target vehicle in a near zone of the host vehicle;

determining a first target vehicle dynamic comprising determining a range, range rate and bearing angle value for each of a plurality of time values for said first target vehicle;

calculating a future position of said first target vehicle from said first target vehicle dynamic by fitting said first target vehicle dynamic to a generalized conic curve;

sensing the host vehicle in motion;

tracking a current host vehicle dynamic;

calculating intersect coordinates for said first target vehicle and said host vehicle at a future time based on said host vehicle dynamic and said future position of said first target vehicle;

calculating a potential for collision between the host vehicle and said first target vehicle; and

determining whether said potential for collision of the host vehicle and said first target vehicle is within a pre-determined safety threshold response time.

14. The method of claim 13 wherein said step of calculating a potential for collision comprises determining time values when said first target vehicle will arrive at said intersect coordinates.

15. The method of claim 13 wherein said generalized conic curve is of the form:

16. The method of claim 13 wherein said step of calculating a future position of said first target vehicle includes estimating acceleration and velocity values of said first target vehicle at a future time value.