Light impact detection for vehicle using low computation overhead

• US 10,417,913 B2
• Filed: 03/15/2016
• Issued: 09/17/2019
• Est. Priority Date: 03/15/2016
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Panigrahi, Smruti R., Lu, Jianbo, Hong, Sanghyun, Scott, Jonathan, Filev, Dimitar P.
• Primary Examiner(s): Shah, Tanmay K
• Application Number:
  US16/085,374
• Publication Number:
  US 20190088134A1
• Time in Patent Office: 1,281 Days
• Field of Search: 340436
• 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: B60R 21/0136 responsive to actual contact with an obstacle , e.g. to vehicle deformation, bumper displacement or bumper velocity relative to the vehicle monitoring crash strength in combination with passenger seat detection B60R21/01558
• CPC Class Codes: G01L 5/0052 measuring forces due to impact G01L5/0061, G01L5/14 take precedence; impact testing of structures G01M7/08; impact testing of material G01N3/00
• CPC Class Codes: G07C 5/008 communicating information to a remotely located station transmission systems for measured values G08C
• CPC Class Codes: G07C 5/085 using electronic data carriers
• CPC Class Codes: G08G 1/162 event-triggered

Abstract

Light or moderate impacts against a vehicle are detected. Measured acceleration and yaw rate are compared to baseline thresholds in a baseline state. When the acceleration is above the threshold, a distance from an estimated impact location to a vehicle center-of-gravity is determined. When the determined distance is less than a vehicle edge distance, an impact-suspected state will be entered if at least one of the acceleration and yaw rate is above the respective threshold for a predetermined duration. In the impact-suspected state, a plurality of vehicle dynamic behaviors are monitored for confirming occurrence of the light impact. A return is made to the baseline state if the acceleration and yaw rate fail to remain above the respective threshold or if the calculated distance fails to remain less than the edge distance. The impact is detected when at least one of the behaviors confirms the occurrence.

Claims

1. A method of detecting a light impact against a vehicle, comprising:

(a) comparing a measured acceleration and a measured yaw rate to respective baseline thresholds in a baseline state;

(b) when the acceleration is above the respective baseline threshold, then determining a center-of-gravity to impact distance according to a mass of the vehicle, a moment of inertia of the vehicle, the measured acceleration of the vehicle, and the measured yaw rate of the vehicle;

(c) when the determined distance is less than a vehicle edge distance, then entering an impact-suspected state when at least one of the acceleration and yaw rate is above the respective baseline threshold for a first predetermined duration;

(d) in the impact-suspected state, monitoring a plurality of vehicle dynamic behaviors for confirming occurrence of the light impact, wherein the method returns to the baseline state if the acceleration and yaw rate fail to remain above the respective baseline threshold or if the determined distance fails to remain less than the vehicle edge distance; and

(e) detecting the light impact when at least one of the behaviors confirms the occurrence.

2. The method of claim 1 wherein the behaviors include:

confirming the light impact when at least one of the acceleration and yaw rate remains above the respective baseline threshold for a second predetermined duration greater than the first predetermined duration.

3. The method of claim 1 wherein the behaviors include:

determining a difference in vehicle velocities measured at two different times; and

confirming the light impact when the difference is greater than a predetermined difference.

4. The method of claim 3 wherein the vehicle velocities are longitudinal velocities.

5. The method of claim 3 wherein the vehicle velocities are lateral velocities.

6. The method of claim 1 wherein the behaviors include:

determining a side slip ratio for each of a front axle and a rear axle of the vehicle; and

confirming the light impact when at least one of the side slip ratios is greater than a predetermined side slip ratio.

7. The method of claim 1 wherein the behaviors include:

confirming the light impact when the yaw rate exceeds a predetermined maximum angular velocity.

8. The method of claim 1 wherein the behaviors include:

determining a lane departure acceleration in response to the yaw rate and a longitudinal velocity of the vehicle; and

confirming the light impact when the lane departure acceleration exceeds a lane departure threshold.

9. The method of claim 1 wherein the center-of-gravity to impact distance is further determined according to a recursive least squares fit.

10. The method of claim 1 wherein the measured acceleration is comprised of a total acceleration derived from measured longitudinal acceleration and measured lateral acceleration.

11. A vehicle apparatus comprising:

vehicle dynamics sensors measuring vehicle acceleration and yaw;

a controller network with at least one controller module communicatively coupled to the dynamics sensors, wherein the controller network;

a) compares a measured acceleration and a measured yaw rate to respective baseline thresholds in a baseline state;

(b) if the acceleration is above the respective baseline threshold, determines a center-of-gravity to impact distance according to a mass of the vehicle, a moment of inertia of the vehicle, the measured acceleration of the vehicle, and the measured yaw rate of the vehicle;

(c) if the determined distance is less than a vehicle edge distance, then enters an impact-suspected state when at least one of the acceleration and yaw rate is above the respective baseline threshold for a first predetermined duration;

(d) in the impact-suspected state, monitors a plurality of vehicle dynamic behaviors for confirming occurrence of the light impact, wherein the controller network returns to the baseline state if the measured acceleration and yaw rate fail to remain above the respective baseline threshold or if the determined distance fails to remain less than the vehicle edge distance; and

(e) detects the light impact when at least one of the behaviors confirms the occurrence.

12. The vehicle apparatus of claim 11 further comprising non-volatile storage for recording data associated with the confirmed light impact including a time, a date, and a location.

13. The vehicle apparatus of claim 11 further including a passive restraint system triggered in response to impacts having a severity greater than a severity of the light impact, wherein the passive restraint system performs an impact detection function that is adjusted in response to confirmation of a light impact.

14. The vehicle apparatus of claim 11 wherein the behaviors include:

confirming the light impact when at least one of the acceleration and yaw rate remaining above the respective baseline threshold for a second predetermined duration greater than the first predetermined duration.

15. The vehicle apparatus of claim 11 wherein the behaviors include:

determining a difference in vehicle velocities measured at two different times; and

confirming the light impact when the difference is greater than a predetermined difference.

16. The vehicle apparatus of claim 11 wherein the behaviors include:

determining a side slip ratio for each of a front axle and a rear axle of the vehicle; and

confirming the light impact when at least one of the side slip ratios is greater than a predetermined side slip ratio.

17. The vehicle apparatus of claim 11 wherein the behaviors include:

confirming the light impact when the yaw rate exceeds a predetermined maximum angular velocity.

18. The vehicle apparatus of claim 11 wherein the behaviors include:

determining a lane departure acceleration in response to the yaw rate and a longitudinal velocity of the vehicle; and

confirming the light impact when the lane departure acceleration exceeds a lane departure threshold.

19. The vehicle apparatus of claim 11 wherein the center-of-gravity to impact distance is calculated according to a recursive least squares fit.

20. The vehicle apparatus of claim 11 wherein the measured acceleration is comprised of a total acceleration derived from measured longitudinal acceleration and measured lateral acceleration.