Method for determining a rolling condition via frequency analysis of the rotation of the suspension stop

• US 20070255467A1
• Filed: 04/24/2007
• Published: 11/01/2007
• Est. Priority Date: 04/27/2006
• Status: Abandoned Application

• Current Assignee: SNR Roulements
• Original Assignee: SNR Roulements
• Inventors: Blanchin, Olivier
• Application Number:
  US11/789,340
• Publication Number:
  US 20070255467A1
• Time in Patent Office: Days
• US Class Current: 701/38
• CPC Class Codes: B60C 23/061 by monitoring wheel speed measuring distance traversed on the ground by vehicles G01C22/00
• CPC Class Codes: B60C 23/062 Frequency spectrum analysis of wheel speed signals, e.g. using Fourier transformation
• CPC Class Codes: B60G 15/068 specially adapted for MacPherson strut-type suspension
• CPC Class Codes: B60G 17/0162 mainly during a motion involving steering operation, e.g. cornering, overtaking B60G17/0164 takes precedence
• CPC Class Codes: B60G 17/018 characterised by the use of a specific signal treatment or control method
• CPC Class Codes: B60G 2200/46 camber angle
• CPC Class Codes: B60G 2202/12 Wound spring
• CPC Class Codes: B60G 2202/312 The spring being a wound spring
• CPC Class Codes: B60G 2204/11 Mounting of sensors thereon
• CPC Class Codes: B60G 2204/112 on dampers, e.g. fluid dampers
• CPC Class Codes: B60G 2204/124 Mounting of coil springs
• CPC Class Codes: B60G 2204/128 Damper mount on vehicle body or chassis
• CPC Class Codes: B60G 2204/418 Bearings, e.g. ball or roller bearings
• CPC Class Codes: B60G 2204/43 Fittings, brackets or knuckles
• CPC Class Codes: B60G 2204/44 Centering or positioning means
• CPC Class Codes: B60G 2204/4502 using resilient buffer
• CPC Class Codes: B60G 2204/61 Adjustable during maintenance
• CPC Class Codes: B60G 2400/206 Body oscillation speed; Body vibration frequency
• CPC Class Codes: B60G 2400/52 in tyre
• CPC Class Codes: B60G 2400/91 Frequency
• CPC Class Codes: B60G 2600/188 : Spectral analysis; Transformations
• CPC Class Codes: B60G 2800/012 : Rolling condition
• CPC Class Codes: B60G 2800/92 : ABS - Brake Control
• CPC Class Codes: B60G 2800/94 : Electronic Stability Program (ESP, i.e. ABS+ASC+EMS)
• CPC Class Codes: F16C 19/163 : with angular contact
• CPC Class Codes: F16C 19/527 : related to vibration and noise
• CPC Class Codes: F16C 2233/00 : Monitoring condition, e.g. temperature, load, vibration
• CPC Class Codes: F16C 2326/05 : Vehicle suspensions, e.g. bearings, pivots or connecting rods used therein in general B60G
• CPC Class Codes: F16C 41/008 : Identification means, e.g. markings, RFID-tags; Data transfer means

Abstract

A method for determining at least one rolling condition of a motor vehicle wheel, which wheel being mounted on the chassis of the vehicle via a MacPherson strut integrating a suspension stop which includes a rotating component in relation to the chassis is described. The method envisages using a device for detecting the angular displacements of the rotating component, which device is suitable for generating an analogue signal which is representative of the angular displacements according to time. The method envisages carrying out a frequency analysis of the analogue displacement signal such as to obtain a spectrum including at least one frequency window wherein at least one datum of the spectrum is based on a rolling parameter; measuring at least one of the data; determining, from the measured datum or data, at least one rolling condition corresponding to the rolling parameter or to the development of the rolling parameter.

Claims

1. A method for determining at least one rolling condition of a motor vehicle wheel, said wheel being mounted on a chassis of said vehicle via a MacPherson strut integrating a suspension stop which includes a rotating component in relation to the chassis, said method comprising using a device for detecting the angular displacements of the rotating component;

using said device to generate an analogue signal which is representative of said angular displacements according to time;

carrying out a frequency analysis of the analogue displacement signal such as to obtain a spectrum including at least one frequency window wherein at least one datum of said spectrum is based on a rolling parameter;

measuring at least one of said data; and

determining, from the measured datum or data, at least one rolling condition corresponding to the rolling parameter or to the development of said rolling parameter.

2. A determination method according to claim 1, wherein the frequency analysis step comprises performing the frequency analysis via temporal FFT Fourier transform.

3. A determination method according to claim 1, wherein the at least one frequency window includes at least one line, and further said method further comprises choosing a function datum of the rolling parameter from a group consisting of an amplitude of the at least one line, a width of the at least one line, a frequency of the at least one line, and a combination thereof.

4. A determination method according to claim 1, further comprising choosing the rolling parameter from a group of parameters influencing the stiffness of the assembly including the wheel and the MacPherson strut.

5. A determination method according to claim 4, wherein said choosing step comprising choosing the rolling parameter from the group consisting of a tire pressure of the wheel, a wear state of the tire, and a state of a shock absorber of the MacPherson strut.

6. A determination method according to claim 1, wherein the rolling condition determining step comprises comparing the measured datum with a calibration value corresponding to the rolling parameter.

7. A determination method according to claim 5, further comprising periodically recording the rolling parameter and adjusting the calibration value according to a history of values recorded.

8. A determination method according to claim 1, wherein the rolling condition determining step comprises comparing a variation of a rolling parameter with a threshold corresponding to said condition.

9. A determination method according to claim 8, further comprising periodically recording the rolling parameter and comparing said parameter with at least one value recorded so as to determine the rolling condition.

10. A determination method according to claim 1, further comprising determining the rolling condition using at least one other rolling parameter selected fro the group consisting of a steering angle operating the wheel, a rotation speed of the wheel, a deformation of the suspension stop, a pressing down of the suspension and/or a rotation angle of the rotating component of the stop, and a pressure of at least one of the tires of the other wheels where the rolling condition determined is the pressure of the tire of the wheel.

11. An assembly including a suspension stop integrated into a MacPherson strut via which a motor vehicle wheel is mounted on a chassis of a vehicle, said stop including a fixed component and a rotating component on which a suspension spring is resting, said assembly including a device for detecting angular displacements of the rotating component in relation to the fixed component, said device generating an analog signal which is representative of said angular displacements according to time, said assembly further including a device for determining at least one rolling condition of the wheel, means for frequency analysis of the analog displacement signal, means for measuring at least one datum of a spectrum and processing means for determining at least one rolling condition of the wheel.