Tire pressure decrease detection apparatus, method, and program

Patent metadata

Field	Value
Publication number	US-9970839-B2
Application number	US-201514867811-A
Country	US
Kind code	B2
Filing date	Sep 28, 2015
Priority date	Nov 11, 2014
Publication date	May 15, 2018
Grant date	May 15, 2018

Abstract

A tire pressure decrease detection apparatus comprising a rotation speed information detection unit for detecting rotation speed information of wheels of a vehicle, a resonance frequency estimate unit for time-series estimating a torsional resonance frequency of the rotation speed information from the rotation speed information obtained by the rotation speed information detection unit, and a judgment unit for judging a decrease in pressure of tires installed in the wheels based on the estimated torsional resonance frequency. The resonance frequency estimate unit includes a noise removal unit for removing a noise superimposed on a wheel speed signal serving as the rotation speed information for each of the wheels with using an active noise control technology.

First claim

What is claimed is:

1. A tire pressure decrease detection apparatus comprising:
a rotation speed information detection unit for detecting rotation speed information of wheels of a vehicle;
a resonance frequency estimate unit for time-series estimating a torsional resonance frequency of the rotation speed information from the rotation speed information obtained by the rotation speed information detection unit; and
a judgment unit for judging a decrease in pressure of tires installed in the wheels based on the estimated torsional resonance frequency,
wherein the resonance frequency estimate unit includes a noise removal unit for removing a noise superimposed on a wheel speed signal serving as the rotation speed information for each of the wheels with using an active noise control technology;
wherein the active noise control technology is a Finite Impulse Response (FIR) type adaptive digital filter using a past signal of the wheel speed signal serving as an object to be controlled as a reference signal, and an LMS algorithm as an adaptive algorithm,
wherein a time difference Δt (sec) between an acquired time of the past signal used as the reference signal and a current time satisfies a formula of 0.16≤Δt≤≤0.35,
wherein the tire pressure decrease detection apparatus is further configured to apply the judged decrease in pressure to the vehicle to generate a report regarding the tire pressure, which eliminates an erroneous report or non-alarm and eliminates an influence of the noise superimposed on the wheel speed signal, to affect operation of the vehicle, and
wherein the noise removal unit functions at vehicle speed of 30 to 120 kph, and a calculation cycle of the noise removal unit is 3 to 10 msec.

2. A tire pressure decrease detection apparatus comprising:
a rotation speed information detection unit for detecting rotation speed information of wheels of a vehicle;
a rotation acceleration information calculation unit for calculating rotation acceleration information of the wheels from the rotation speed information obtained by the rotation speed information detection unit;
a resonance frequency estimate unit for time-series estimating a torsional resonance frequency of the rotation acceleration information from the rotation acceleration information calculated by the rotation acceleration information calculation unit; and
a judgment unit for judging a decrease in pressure of the tires based on the estimated torsional resonance frequency,
wherein the resonance frequency estimate unit includes a noise removal unit for removing a noise superimposed on a wheel acceleration signal serving as the rotation acceleration information for each of the wheels with using an active noise control technology;
wherein the active noise control technology is a Finite Impulse Response (FIR) type adaptive digital filter using a past signal of the wheel acceleration signal serving as an object to be controlled as a reference signal, and an LMS algorithm as an adaptive algorithm,
wherein a time difference Δt (sec) between an acquired time of the past signal used as the reference signal and a current time satisfies a formula of 0.16≤Δt≤0.35, and
wherein the tire pressure decrease detection apparatus is further configured to apply the judged decrease in pressure to the vehicle to generate a report regarding the tire pressure, which eliminates an erroneous report or non-alarm and eliminates an influence of the noise superimposed on the wheel acceleration signal, to affect operation of the vehicle.

3. A tire pressure decrease detection apparatus comprising:
a rotation speed information detection unit for detecting rotation speed information of wheels of a vehicle;
a resonance frequency estimate unit for time-series estimating a torsional resonance frequency of the rotation speed information from the rotation speed information obtained by the rotation speed information detection unit; and
a judgment unit for judging a decrease in pressure of tires installed in the wheels based on the estimated torsional resonance frequency,
wherein the resonance frequency estimate unit includes a noise removal unit for removing a noise superimposed on a wheel speed signal serving as the rotation speed information for each of the wheels with using an active noise control technology;
wherein the active noise control technology is a Finite Impulse Response (FIR) type adaptive digital filter using a wheel speed signal of the other wheel on the same axle as the wheel of which an engine noise is to be removed as a reference signal, and an LMS algorithm as an adaptive algorithm,
wherein a time difference Δt (sec) between an acquired time of the signal used as the reference signal and a current time satisfies a formula of 0≤Δt≤0.35, in which “acquired time of reference signal”=“current time”−Δt, and
wherein the tire pressure decrease detection apparatus is further configured to apply the judged decrease in pressure to the vehicle to generate a report regarding the tire pressure, which eliminates an erroneous report or non-alarm and eliminates an influence of the noise superimposed on the wheel speed signal, to affect operation of the vehicle.

4. The tire pressure decrease detection apparatus of claim 3 , wherein the noise removal unit functions at vehicle speed of 30 to 120 kph, and a calculation cycle of the noise removal unit is 3 to 10 msec.

5. The tire pressure decrease detection apparatus of claim 4 , wherein the tire pressure decrease detection apparatus satisfies a formula of K×4≤N≤50, wherein N is a tap number of the FIR type adaptive digital filter and K is the number of the noise to be removed.

6. A tire pressure decrease detection apparatus comprising:
a rotation speed information detection unit for detecting rotation speed information of wheels of a vehicle;
a rotation acceleration information calculation unit for calculating rotation acceleration information of the wheels from the rotation speed information obtained by the rotation speed information detection unit;
a resonance frequency estimate unit for time-series estimating a torsional resonance frequency of the rotation acceleration information from the rotation acceleration information calculated by the rotation acceleration information calculation unit; and
a judgment unit for judging a decrease in pressure of the tires based on the estimated torsional resonance frequency,
wherein the resonance frequency estimate unit includes a noise removal unit for removing a noise superimposed on a wheel acceleration signal serving as the rotation acceleration information for each of the wheels with using an active noise control technology;
wherein the active noise control technology is a Finite Impulse Response (FIR) type adaptive digital filter using a wheel speed signal of the other wheel on the same axle as the wheel of which an engine noise is to be removed as a reference signal, and an LMS algorithm as an adaptive algorithm,
wherein a time difference Δt (sec) between an acquired time of the signal used as the reference signal and a current time satisfies a formula of 0≤Δt≤0.35, in which “acquired time of reference signal”=“current time”−Δt, and
wherein the tire pressure decrease detection apparatus is further configured to apply the judged decrease in pressure to the vehicle to generate a report regarding the tire pressure, which eliminates an erroneous report or non-alarm and eliminates an influence of the noise superimposed on the wheel acceleration signal, to affect operation of the vehicle.

7. The tire pressure decrease detection apparatus of claim 6 , wherein the noise removal unit functions at vehicle speed of 30 to 120 kph, and a calculation cycle of the noise removal unit is 3 to 10 msec.

8. The tire pressure decrease

Assignees

• Sumitomo Rubber Ind

Inventors

• Yanase Minao

Classifications

• B60C23/061 Primary

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

• G01L17/00 Primary

  Devices or apparatus for measuring tyre pressure or the pressure in other inflated bodies · CPC title

• B60C23/062

  Frequency spectrum analysis of wheel speed signals, e.g. using Fourier transformation · CPC title

• G01P3/00

  Measuring linear or angular speed; Measuring differences of linear or angular speeds (G01P5/00 - G01P11/00 take precedence; {direction and speed indication G01P13/045}; counting mechanisms G06M) · CPC title

• B60C23/00 Primary

  Devices for measuring, signalling, controlling, or distributing tyre pressure or temperature, specially adapted for mounting on vehicles; Arrangement of tyre inflating devices on vehicles, e.g. of pumps or of tanks; Tyre cooling arrangements · CPC title