Method and device for estimating a current wheel circumference of at least one wheel arranged on a vehicle

Patent metadata

Field	Value
Publication number	US-11512950-B2
Application number	US-202117494145-A
Country	US
Kind code	B2
Filing date	Oct 5, 2021
Priority date	Jul 16, 2018
Publication date	Nov 29, 2022
Grant date	Nov 29, 2022

Abstract

The invention relates to a method for estimating a current wheel circumference of at least one wheel arranged on a vehicle, said method comprising: determining a reference speed of the vehicle at a point in time by means of a reference apparatus, detecting a wheel rotational speed of the at least one wheel at said point in time by means of a wheel rotational speed sensor, estimating a single wheel-circumference value based on the determined reference speed and the detected wheel rotational speed for said point in time by means of a calculation apparatus, storing at least the estimated single wheel-circumference value in a circular buffer for said point in time, estimating a current wheel circumference based on the single wheel-circumference values stored in the circular buffer by the calculation apparatus, outputting the estimated current wheel circumference as a wheel circumference signal.

First claim

The invention claimed is:

1. A method for estimating a current wheel circumference of at least one wheel arranged on a vehicle, comprising:
determining a reference speed of the vehicle at a point in time;
sensing a wheel rotational speed of the at least one wheel at the point in time by a wheel rotational speed sensor;
estimating a wheel-circumference value based on the determined reference speed and the sensed wheel rotational speed for the point in time, wherein a validity of the determined reference speed and sensed wheel rotational speed is checked;
storing at least the wheel-circumference value for the point in time in a circular buffer, which circular buffer uses First-In-First-Out (FIFO) logic, wherein the wheel-circumference value only being stored for the point in time when the determined reference speed and sensed wheel rotational speed are valid for the point in time;
repeating the determining of the reference speed of the vehicle, sensing of the wheel rotational speed of the at least one wheel, and the estimating of the wheel-circumference value for at least one other point in time so that a plurality of wheel-circumference values are stored in the circular buffer;
estimating a current wheel circumference based on the plurality of wheel-circumference values stored in the circular buffer; and
outputting the estimated current wheel circumference for estimating a current speed of the vehicle.

2. The method according to claim 1 , wherein the current wheel circumference is estimated based on a weighted mean value of the plurality of wheel-circumference values stored in the circular buffer.

3. The method according to claim 2 , wherein a quality of the plurality of wheel-circumference values stored in the circular buffer is determined.

4. The method according to claim 1 , wherein a quality of at least one of the plurality of wheel-circumference values stored in the circular buffer is determined.

5. The method according to claim 4 , wherein the quality is determined depending on an age of at least one of the plurality of wheel-circumference values in the circular buffer.

6. The method according to claim 5 , wherein the quality is determined depending on the determined reference speed associated with the respective wheel-circumference value.

7. The method according to claim 4 , wherein the quality is determined depending on the determined reference speed associated with the respective single wheel-circumference value.

8. The method according to claim 1 , wherein an overall quality of the circular buffer is ascertained, wherein the current wheel circumference additionally being estimated on a basis of the ascertained overall quality of the circular buffer.

9. The method according to claim 8 , wherein the current wheel circumference is estimated based on a characteristic curve, the characteristic curve defining a weighting between a wheel circumference estimated on a basis of the plurality of wheel-circumference values stored in the circular buffer and a fallback wheel circumference depending on the ascertained overall quality of the circular buffer.

10. The method according to claim 1 , wherein the determined reference speed at a respective point in time is also stored in the circular buffer, wherein the current wheel circumference being estimated exclusively on a basis of one or more of the plurality of wheel-circumference values in the circular buffer of which the associated reference speeds correspond to a speed range within which the current speed of the vehicle lies at a current point in time.

11. The method according to claim 1 , wherein a quality of the plurality of wheel-circumference values stored in the circular buffer is determined.

12. A device for estimating a current wheel circumference of at least one wheel arranged on a vehicle, said device comprising:
an input apparatus, comprising a processor;
a calculation apparatus, comprising a processor;
a circular buffer, comprising a processor; and
an output apparatus, comprising a processor;
wherein the input apparatus is configured to receive a reference speed of the vehicle from a reference apparatus at least at one point in time and to receive a wheel rotational speed of the at least one wheel from a wheel rotational speed sensor at the at least one point in time;
wherein the calculation apparatus is configured to estimate a wheel-circumference value based on the received reference speed and the received wheel rotational speed for the at least one point in time, wherein a validity of the received reference speed and received wheel rotational speed is checked and the wheel-circumference value for said point in time is stored in the circular buffer, wherein the wheel-circumference value only being stored for the point in time when the determined reference speed and determined wheel rotational speed are valid for the point in time;
wherein, in case a plurality of wheel-circumference values are stored in the circular buffer for a plurality of points in time, the calculation apparatus is configured to estimate a current wheel circumference based on the plurality of wheel-circumference values stored in the circular buffer; and
wherein the output apparatus is configured to output the estimated current wheel circumference for estimating a current speed of the vehicle.

Assignees

• Volkswagen Ag

Inventors

• Hinz Olaf
• Hufer Laurens
• Lamping Roy

Classifications

• B60W40/12 Primary

  related to parameters of the vehicle itself {, e.g. tyre models} · CPC title

• B60W2520/10

  Longitudinal speed · CPC title

• B60W2520/28

  Wheel speed · CPC title

• B60C23/061

  by monitoring wheel speed (measuring distance traversed on the ground by vehicles G01C22/00) · CPC title

• B60C2019/004

  Tyre sensors other than for detecting tyre pressure · CPC title