Method for controlling the suspension of a vehicle by processing images from at least one on-board camera

Patent metadata

Field	Value
Publication number	US-10127650-B2
Application number	US-201515500317-A
Country	US
Kind code	B2
Filing date	Jul 23, 2015
Priority date	Jul 31, 2014
Publication date	Nov 13, 2018
Grant date	Nov 13, 2018

Abstract

The disclosed method checks the state of degradation of the suspension of a vehicle without having to carry out tests that immobilize the vehicle or to use non-objective expertise. The method processes data provided by at least one front camera in an on-board visual system. The checking method includes steps for periodically acquiring images provided by the camera or cameras, followed by storage of the positional data of the three-dimensional road in relation to a flat road and basic positional parameter data for the path of the vehicle. The error between the ideal values of the suspension parameters of a chosen suspension model and the values of these parameters corresponding to the stored path data from the positional data is then minimized. By iteration, the accuracy ε of the error reaches a predetermined value sufficient to diagnose a state of the suspension.

First claim

The invention claimed is:

1. A method for checking the state of degradation of a suspension system ( 10 ) fitted to a motor vehicle ( 1 ), comprising:
periodically acquiring ( 210 ), by at least one camera ( 6 , 7 ) of a visual system ( 60 ) carried on board the vehicle ( 1 ), successive images of a road ( 110 ) within a forward field of vision (Va) of the at least one camera, and storing said images of the road ( 110 ) in the form of pixels in a data storage;
using image processing ( 220 ) to determine and store, from the stored pixels of the road ( 110 ) and from stored pixels of a flat reference road ( 100 ), positional data corresponding to relative values of a profile of the road ( 110 ) in relation to a linear profile of the reference road ( 100 );
determining and storing ( 230 ), from the stored pixels of the road ( 110 ), rotational and translational positional parameter data of the vehicle;
using the determined relative positional data, the determined rotational and translational positional parameter data of the vehicle, and a speed of the vehicle to determine ( 235 ) a path (Ts) of the vehicle ( 1 );
carrying out and iterating a minimization function of an error (ΔP 2 ) between stored suspension parameter values (K, C) of an ideal model suspension and suspension parameter values corresponding to the determined path (Ts) until an accuracy ε of said error (ΔP 2 ) reaches a predetermined value ε R ; and
upon a value of the accuracy ε reaching the predetermined value ε R , diagnosing a state of the suspension ( 270 ) as a function of the error (ΔP 2 ) in order to trigger an alarm in the event of of a pre-critical suspension state.

2. The method for checking the state of a suspension system as claimed in claim 1 , wherein the on-board visual system is a stereoscopic system ( 60 ) comprising two cameras ( 6 , 7 ) that generate successive pairs of images and generate three-dimensional data on the basis of disparities between each pair of images.

3. The method for checking the state of a suspension system as claimed in claim 2 , further comprising:
digitally filtering a noise of said disparities.

4. The method for checking the state of a suspension system as claimed in claim 3 , wherein the flat reference road ( 100 ) determined by averaging standard deviations of the positional data of the road ( 110 ) with a predetermined number of pixels.

5. The method for checking the state of a suspension system as claimed in claim 3 , wherein the path (Ts) of the vehicle ( 1 ) is determined ( 235 ) by successive values of parameters relating to a height of the road ( 110 ) and a height of the vehicle ( 1 ), and positional parameter values of said rotational and translational positional parameter data of the vehicle, including at least one of a roll rotation and a pitch rotation of the vehicle ( 1 ), said positional parameter values being determined using the acquired and stored positional data and said rotational and translational positional parameter data.

6. The method for checking the state of a suspension system as claimed in claim 3 , wherein a model suspension is selected for each wheel ( 5 a , 5 b ) of the vehicle ( 1 ) from a library ( 240 ) stored in the data storage, including a model for a single-stage suspension system, and for a two-stage suspension system.

7. The method for checking the state of a suspension system as claimed in claim 2 , wherein the flat reference road ( 100 ) determined by averaging standard deviations of the positional data of the road ( 110 ) with a predetermined number of pixels.

8. The method for checking the state of a suspension system as claimed in claim 2 , wherein the path (Ts) of the vehicle ( 1 ) is determined ( 235 ) by successive values of parameters relating to a height of the road ( 110 ) and a height of the vehicle ( 1 ), and positional parameter values of said rotational and translational positional parameter data of the vehicle, including at least one of a roll rotation and a pitch rotation of the vehicle ( 1 ), said positional parameter values being determined using the acquired and stored positional data and said rotational and translational positional parameter data.

9. The method for checking the state of a suspension system as claimed in claim 2 , wherein a model suspension is selected for each wheel ( 5 a , 5 b ) of the vehicle ( 1 ) from a library ( 240 ) stored in the data storage, including a model for a single-stage suspension system, and for a two-stage suspension system.

10. The method for checking the state of a suspension system as claimed in claim 2 , wherein the suspension system ( 10 ) is controlled using active, semi-active or passive control ( 6 A, 6 B).

11. The method for checking the state of a suspension system as claimed in claim 1 , wherein the flat reference road ( 100 ) determined by averaging standard deviations of the positional data of the road ( 110 ) with a predetermined number of pixels.

12. The method for checking the state of a suspension system as claimed in claim 11 , wherein the path (Ts) of the vehicle ( 1 ) is determined ( 235 ) by successive values of parameters relating to a height of the road ( 110 ) and a height of the vehicle ( 1 ), and positional parameter values of said rotational and translational positional parameter data of the vehicle, including at least one of a roll rotation and a pitch rotation of the vehicle ( 1 ), said positional parameter values being determined using the acquired and stored positional data and said rotational and translational positional parameter data.

13. The method for checking the state of a suspension system as claimed in claim 11 , wherein a model suspension is selected for each wheel ( 5 a , 5 b ) of the vehicle ( 1 ) from a library ( 240 ) stored in the data storage, including a model for a single-stage suspension system, and for a two-stage suspension system.

14. The method for checking the state of a suspension system as claimed in claim 1 , wherein the path (Ts) of the vehicle ( 1 ) is determined ( 235 ) by successive values of parameters relating to a height of the road ( 110 ) and a height of the vehicle ( 1 ), and positional parameter values of said rotational and translational positional parameter data of the vehicle, including at least one of a roll rotation and a pitch rotation of the vehicle ( 1 ), said positional parameter values being determined using the acquired and stored positional data and said rotational and translational positional parameter data.

15. The method for checking the state of a suspension system as claimed in claim 14 , wherein a model suspension is selected for each wheel ( 5 a , 5 b ) of the vehicle ( 1 ) from a library ( 240 ) stored in the data storage, including a model for a single-stage suspension system, and for a two-stage suspension system.

16. The method for checking the state of a suspension system as claimed in claim 1 , wherein a model suspension is selected for each wheel ( 5 a , 5 b ) of the vehicle ( 1 ) from a library ( 240 ) stored in the data storage, including a model for a single-stage suspension system, and for a two-stage suspension system.

17. The method for checking the state of a suspension system as claimed in claim 16 , wherein the suspension parameters of the model suspension comprise a spring stiffness (K) and a shock absorber compression ratio (C) for each wheel ( 2 a , 2 b ).

18. The method for checking the state of a suspension system as claimed in claim 1 , wherein the suspension system ( 10 ) is controlled using one of active, semi-active, or passiv

Assignees

• Continental Automotive France
• Continental Automotive Gmbh

Inventors

• Garcia Lucien

Classifications

• B60G17/019

  characterised by the type of sensor or the arrangement thereof {(B60G17/01941 takes precedence)} · CPC title

• G06T2207/30164

  Workpiece; Machine component · CPC title

• B60G2800/70

  Estimating or calculating vehicle parameters or state variables · CPC title

• H04N13/239 Primary

  using two two-dimensional [2D] image sensors having a relative position equal to or related to the interocular distance (H04N13/243 takes precedence) · CPC title

• B60R2300/105

  using multiple cameras · CPC title