METHOD FOR ESTIMATING THE RELIABILITY OF MEASUREMENTS BY WHEEL SENSORS OF A VEHICLE AND SYSTEM FOR ITS APPLICATION

• US 20160178481A1
• Filed: 12/14/2015
• Published: 06/23/2016
• Est. Priority Date: 12/17/2014
• Status: Active Grant

• Current Assignee: Continental Automotive France (Continental AG), Continental Automotive GmbH (Continental AG)
• Original Assignee: Continental Automotive France (Continental AG), Continental Automotive GmbH (Continental AG)
• Inventors: FUDULEA, Olivier
• Granted Patent: US 10,132,719 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B60C 23/0477 Evaluating waveform of pressure readings
• CPC Class Codes: B60C 23/0481 System diagnostic, e.g. monitoring battery voltage, detecting hardware detachments or identifying wireless transmission failures
• CPC Class Codes: B60C 23/067 by monitoring chassis to ground distance
• CPC Class Codes: B60T 8/171 Detecting parameters used in the regulation; Measuring values used in the regulation
• CPC Class Codes: G01M 17/013 Wheels
• CPC Class Codes: G07C 5/0808 Diagnosing performance data testing of vehicles G01M17/00; testing of electrical installation on vehicles G01R31/005

Abstract

A method and system for evaluating the reliability of data supplied by multi-function WFC sensors of tires of wheels of a vehicle for targeted applications, on the basis of the irregularities of the road, which use displacement data sent from the road handling adaptation equipment of the vehicle, enabling the variations in the road condition to be reflected. The system includes equipment for monitoring the wheel displacement data for adapting it to the variations of profile of the road on which it is traveling, in order to maintain a stable body position. The monitoring equipment is linked to the WFC sensors via a central processing unit which is capable of correlating data supplied by the WFC sensors and values of wheel displacement data supplied by the monitoring equipment for the purpose of weighting the values of at least one parameter obtained from the data delivered by the WFC sensors.

Claims

1. A method for estimating the reliability of measurements made periodically by multi-function sensors, known as WFC sensors (12), of tires (1) of wheels (R1 to R4) of a vehicle traveling on a road (2), which comprises, in succession:

a step of extracting (100), from a system for monitoring the vehicle (3, 8) in a given environment for the purpose of adapting its behavior to this environment, periodic data on the vehicle body displacement heights at the position of each wheel (D_R), these data being known as wheel displacement data, indicating a state of the variations of the profile of the road on which the vehicle is traveling,

a step of correlating (140, 240) these wheel displacement data (D_R) with the values of at least one parameter (10) sensitive to the variations in profile of the road (2) for a given application, these values being deduced from the measurements (M₁₂) made by the WFC sensors on each wheel (R1 to R4) at the same instants, and

a step of taking into account the consistency between the displacement data (D_R) and the values of the parameter (10) correlated in the preceding step, by using decision criteria (150), with the aim of deducing a decision on the reliability of a given set of values of the parameter deduced from the measurements of the WFC sensors.

2. The method for estimating the reliability of measurements as claimed in claim 1, wherein the number of wheel displacement data (D_R) is increased (150) until a rate of global correlation between the wheel displacement data (D_R) and the values of said parameter (10) is at least equal to a given correlation threshold (S_sup, S_inf) defining a reliability decision criterion.

3. The method for estimating the reliability of measurements as claimed in claim 1, wherein the application is the location of the WFC sensors (12) on the basis of the position of the wheels (R1 to R4), and the parameter is the length (Δ

L) of the footprint (10) of the tires (1) on the road (2), determined on the basis of an acceleration signal (S_A).

4. The method for estimating the reliability of measurements as claimed in claim 1, wherein the correlation relates to the inverse variations between the wheel displacement data (D_R) and the corresponding values of tire footprint length (Δ

L) of the corresponding tire.

5. The method for estimating the reliability of measurements as claimed in claim 1, wherein the wheel displacement data (D_R) and/or the values of footprint length (Δ

L) are selected on the basis of thresholds of detection of their variation (SL₁, SL₂).

6. The method for estimating the reliability of measurements as claimed in claim 1, wherein the correlation relates to the simultaneous detection of noise (B_D, B_A) in the wheel displacement data (D_R) and in the values of footprint length( Δ

L) of the corresponding tire.

7. The method for estimating the reliability of measurements as claimed in claim 3, wherein, a radial acceleration being detected by the WFC sensor (12), the variations in footprint (10) or the presence of noise (B_A) are directly detected by the WFC sensor (12).

8. The method for estimating the reliability of measurements as claimed in claim 1, wherein the wheel displacement data (D_R) relate (D_R) to the variations in the rolling average (of the wheel displacement data (D_R).

9. The method for estimating the reliability of measurements as claimed in claim 8, wherein the application relates to the location of the WFC sensors (12) by association of the rotation data, deduced from the measurements of an angular detector of the WFC sensors (12), with the wheel revolution data counted by impulse sensors of an anti-lock braking system (ABS) or the equivalent, the average (D_R) of the wheel displacement data D_R being used to weight the validity of the angular offsets to be determined for the assignment of a WFC sensor (12) to each of the wheels (R1 to R4) on the basis of the detection of predetermined successive angular positions (X1, X2, . . . , Xn) of the sensor (12) of each wheel (R1 to R4).

10. The method for estimating the reliability of measurements as claimed in claim 9, wherein each angular position (X1, X2, . . . , Xn) is modulated by the application of weighting coefficients varying as a function of the variations of the displacement data (D_R) for each wheel (R1 to R4) relative to a reference displacement data element in the determination of the dispersion variance (V) of the set of angular positions (X1, X2, . . . , Xn), for the purpose of deducing a reliability decision therefrom, taking into account the consistency between the value of each angular position (X1, X2, . . . , Xn) and the state of the road.

11. The method for estimating the reliability of measurements as claimed in claim 8, wherein the parameter is the measurement of the length (Δ

L) of the footprint (10) of a tire (1) for an application for estimating the load on this tire (1) by introducing weighting coefficients applied to the measurements of footprint length (Δ

L) and varying as a function of the displacement data (D_R) for each wheel (R1 to R4), in relation to the state of degradation of the road, for the purpose of deducing a reliability decision therefrom by elimination of the measurements corresponding to degraded conditions of the state of the road.

12. The method for estimating the reliability of measurements as claimed in claim 8, wherein the parameter is the measurement of a characteristic of the footprint length (Δ

L) of a tire (1), in particular the overshoot (S₀), for an estimation of the wear on this tire (1), by introducing weighting coefficients applied to the measurements of footprint length (Δ

L) and varying as a function of the displacement data (D_R) for each wheel (R1 to R4), in relation to the state of degradation of the road, for the purpose of deducing a reliability decision therefrom by elimination of the measurements corresponding to degraded conditions of the state of the road.

13. The method for estimating the reliability of measurements as claimed in claim 8, wherein the application relates to the position of sensors (12) and the parameter is a function for monitoring the detachment/breakaway of the sensor (12).

14. A system for estimating the reliability of measurements made periodically by multi-function sensors known as WFC sensors (12) of tires (1) of wheels (R1 to R4) of a vehicle capable of traveling on a road (2) and transmitted in the form of digital signals (S_A) to a central processing unit (8) for the application of the method according to claim 1, wherein the system comprises equipment for monitoring (3, 8) the wheel displacement data (D_R) for adapting it to the variations in the profile of the road on which it is traveling in order to maintain a stable body position by means of feedback control, the monitoring equipment being linked to the WFC sensors via the central processing unit which is capable of correlating data supplied by the WFC sensors and values of wheel displacement data supplied by the monitoring equipment for the purpose of weighting the values of at least one parameter obtained from the data delivered by the WFC sensors.

15. The system for estimating the reliability of measurements as claimed in claim 14, wherein the monitoring equipment is selected from among a suspension control system of the vehicle (3, 8), which implicitly supplies monitoring data on the state of the road (2), and a system of stereoscopic cameras, at least one radar system, and a laser sensor which directly supply data on the surface state of the road (2).

16. The system for estimating the reliability of measurements as claimed in claim 15, wherein the suspension control system is a hydroelectronic unit with an integrated computer, known as a BHI, for controlling a hydropneumatic suspension, the BHI unit receiving data from a steering wheel angle sensor and from sensors (3) of the displacement of the vehicle body (4), for the purpose of regulating the suspension flow rate and pressure and the body height.

17. The system for estimating the reliability of measurements as claimed in claim 16, wherein the application of the WFC sensors (12) is the angular location of the wheels (R1 to R4), and the monitoring data on the state of the road (2) supplied by the BHI unit of a hydropneumatic suspension monitoring system are correlated with the acceleration data (S_A) of the WFC sensors (12).

18. The method for estimating the reliability of measurements as claimed in claim 2, wherein the application is the location of the WFC sensors (12) on the basis of the position of the wheels (R1 to R4), and the parameter is the length (Δ

L) of the footprint (10) of the tires (1) on the road (2), determined on the basis of an acceleration signal (S_A).

19. The method for estimating the reliability of measurements as claimed in claim 2, wherein the correlation relates to the simultaneous detection of noise (B_D, B_A) in the wheel displacement data (D_R) and in the values of footprint length (Δ

L) of the corresponding tire.

20. The method for estimating the reliability of measurements as claimed in claim 2, wherein the wheel displacement data (D_R) relate to the variations in the rolling average (D_R) of the wheel displacement data (D_R).