Tire load estimation

Patent metadata

Field	Value
Publication number	US-11945266-B2
Application number	US-202017114831-A
Country	US
Kind code	B2
Filing date	Dec 8, 2020
Priority date	Aug 22, 2018
Publication date	Apr 2, 2024
Grant date	Apr 2, 2024

Abstract

A system for estimating a tire load of a tire includes a pressure sensor configured to generate a tire pressure signal; an acceleration sensor configured to generate a tire acceleration signal; a temperature sensor configured to generate a tire temperature signal; and at least one processor configured to calculate a duration of a contact patch based on the tire acceleration signal, calculate a vehicle speed based on the tire acceleration signal, determine at least one system model coefficient based on the tire pressure signal and the tire temperature signal, and calculate the tire load of the tire using a linear system model that relates tire pressure, the duration of the contact patch, and the vehicle speed to the tire load of the tire, where the linear system model further includes the at least one system model coefficient for calculating the tire load of the tire.

First claim

What is claimed is:

1. A system for estimating a tire load of a tire, comprising:
at least one pressure sensor configured to measure an internal air pressure of the tire and generate at least one tire pressure signal indicating a tire pressure corresponding to the internal air pressure;
at least one acceleration sensor configured to measure an acceleration of the tire and generate at least one tire acceleration signal indicating a tire acceleration corresponding to the acceleration of the tire;
at least one temperature sensor configured to measure a temperature of the tire and generate at least one tire temperature signal indicating the temperature; and
at least one processor configured to:
calculate a duration of a contact patch based on the at least one tire acceleration signal,
obtain a tire wear of the tire based on the at least one tire acceleration signal,
calculate a vehicle speed based on the at least one tire acceleration signal,
select at least one coefficient of a system model from a plurality of stored coefficients based on the at least one tire pressure signal, the at least one tire temperature signal, and the tire wear of the tire, and
calculate the tire load of the tire using the system model that correlates the tire pressure, the duration of the contact patch, and the vehicle speed to the tire load of the tire, wherein the at least one processor uses the at least one coefficient, the tire pressure, the duration of the contact patch, and the vehicle speed in the system model for calculating the tire load of the tire.

2. The system of claim 1 , wherein the at least one processor is configured to receive tire information of the tire, and determine the at least one coefficient based on the at least one tire pressure signal, the at least one tire temperature signal, the tire wear of the tire, and the tire information.

3. The system of claim 2 , further comprising:
a memory configured to store the tire information, wherein the tire information includes at least one of tire brand information, tire dimension information, tire material information, tire stiffness parameters, tire tread information, and tire season information.

4. The system of claim 1 , wherein the at least one processor is configured to select a further coefficient from the plurality of stored coefficients based on the at least one tire pressure signal, the at least one tire temperature signal, and the tire wear of the tire, and use the at least one coefficient, the selected further coefficient, the tire pressure, the duration of the contact patch, and the vehicle speed in the system model for calculating the tire load of the tire.

5. The system of claim 4 , wherein the system model is represented by an equation:
F load =k·p·D·v+d ,
wherein k is a coefficient of the at least one coefficient, d is the selected further coefficient, p is the tire pressure, D is the duration of the contact patch, v is the vehicle speed, and F load is the tire load of the tire.

6. The system of claim 1 , further comprising:
a memory configured to store a tire diameter of the tire,
wherein the at least one processor is configured to calculate a tire rotation period of the tire based on the at least one tire acceleration signal, and to calculate the vehicle speed based on the tire rotation period and the tire diameter.

7. The system of claim 1 , wherein:
the plurality of stored coefficients includes a first slope coefficient and a second slope coefficient, wherein the first slope coefficient and the second slope coefficient are different,
the at least one processor is configured to select the first slope coefficient based on a first set of values corresponding to the at least one tire pressure signal, the at least one tire temperature signal, and the tire wear, and select the second slope coefficient based on a second set of values corresponding to the at least one tire pressure signal, the at least one tire temperature signal, and the tire wear, and
the first set of values and the second set of values are different.

8. A system for estimating a tire load of a tire, comprising:
tire pressure monitoring system (TPMS) sensor module, comprising:
at least one pressure sensor configured to measure an internal air pressure of the tire and generate at least one tire pressure signal indicating a tire pressure corresponding to the internal air pressure;
at least one acceleration sensor configured to measure an acceleration of the tire and generate at least one tire acceleration signal indicating a tire acceleration corresponding to the acceleration of the tire;
at least one temperature sensor configured to measure a temperature of the tire and generate at least one tire temperature signal indicating a tire temperature corresponding to the temperature of the tire;
a microcontroller configured to calculate a duration of a contact patch based on the at least one tire acceleration signal, and to obtain a tire wear of the tire based on the at least one tire acceleration signal; and
a transmitter electrically connected to the microcontroller and configured to transmit the tire pressure, the tire temperature, the duration of the contact patch, and the tire wear of the tire; and

a vehicle electronic control unit (ECU) configured to:
receive the tire pressure, the tire temperature, the duration of the contact patch, and the tire wear of the tire from the transmitter,
select at least one coefficient of a system model from a plurality of stored coefficients based on the at least one tire pressure signal, the at least one tire temperature signal, and the tire wear of the tire, and
calculate the tire load of the tire using the system model that correlates the tire pressure, the duration of the contact patch, and a vehicle speed to the tire load of the tire, wherein at least one processor is configured to use the at least one coefficient, the tire pressure, the duration of the contact patch, and the vehicle speed in the system model for calculating the tire load of the tire.

9. The system of claim 8 , wherein the vehicle ECU is configured to calculate the vehicle speed.

10. The system of claim 8 , wherein the microcontroller is configured calculate the vehicle speed based on the at least one tire acceleration signal, and
the transmitter is configured to transmit the vehicle speed to the vehicle ECU.

11. The system of claim 10 , wherein the TPMS sensor module further comprises:
a memory configured to store a tire diameter of the tire, and
the microcontroller is configured to calculate a tire rotation period of the tire based on the at least one tire acceleration signal, and to calculate the vehicle speed based on the tire rotation period and the tire diameter.

12. The system of claim 8 , wherein the microcontroller is configured to select a further coefficient from the plurality of stored coefficients based on the at least one tire pressure signal, the at least one tire temperature signal, and the tire wear of the tire, and use the at least one coefficient, the selected further coefficient, the tire pressure, the duration of the contact patch, and the vehicle speed in the system model for calculating the tire load of the tire.

13. The system of claim 12 , wherein the system model is represented by an equation:
F load =k·p·D·v+d ,
wherein k is a coefficient of the at least one coefficient, d is the selected further coefficient, p is the tire pressure, D is the duration of the contact patch, v is the vehicle speed, and F load is the tire load of the tire.

Assignees

• Infineon Technologies Ag

Inventors

• Steiner Christoph

Classifications

• B60C23/0474 Primary

  Measurement control, e.g. setting measurement rate or calibrating of sensors; Further processing of measured values, e.g. filtering, compensating or slope monitoring · CPC title

• B60C23/0449

  Passive transducers, e.g. using surface acoustic waves, backscatter technology or pressure sensitive resonators (near field passive transducers B60C23/0428) · CPC title

• B60C23/0476

  Temperature compensation of measured pressure values · CPC title

• B60C23/0488 Primary

  Movement sensor, e.g. for sensing angular speed, acceleration or centripetal force · CPC title

• B60C23/061

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