Method for detecting decompression of tires and device thereof, and program for judging decompression of tires

• US 20080255719A1
• Filed: 06/09/2008
• Published: 10/16/2008
• Est. Priority Date: 11/25/2003
• Status: Active Grant

• Current Assignee: Masashi Kitano
• Original Assignee: Masashi Kitano
• Inventors: Kitano, Masashi
• Granted Patent: US 7,831,346 B2
• Time in Patent Office: Days
• US Class Current: 701/29
• CPC Class Codes: B60C 23/061 by monitoring wheel speed measuring distance traversed on the ground by vehicles G01C22/00
• CPC Class Codes: Y10T 137/3584 Inflatable article [e.g., tire filling chuck and/or stem]
• CPC Class Codes: Y10T 137/36 With pressure-responsive pressure-control means

Abstract

A method for detecting decompression of tires based on the rotational speed of wheels mounted on a vehicle, comprising the steps of: detecting the rotational speed of each of the above-mentioned wheels, determining the speed against ground of the vehicle, calculating the speed information of a fixed wheel from the rotational speeds of said wheels, calculating the judgment value of the wheel position by comparing the speed information of the wheels with the speed against ground of the vehicle, comparing the judgment value of the wheel position with the basis value of the wheel position obtained by preliminarily comparing the speed against ground of the vehicle with the speed information of the wheels at prescribed inner pressure, and judging decompression of tires based on relation between the comparison value of the basis value with the judgment value and a fixed threshold. A region of judging decompression of tires can be broadened and the accuracy of reduced pressure judgment can be improved.

Claims

1. A method for detecting decompression of tires based on the rotational speeds of wheels mounted on a vehicle, comprising the steps of:

detecting the rotational speed of each of said wheels;

determining the speed against ground of said vehicle, wherein the speed against ground of said vehicle is determined by signals demodulated from received radio wave of GPS and time;

calculating the speed information of a fixed wheel from the rotational speeds of said wheels;

memorizing the rotational speed of each of the wheels and the speed information of said wheels;

calculating the judgment value of said wheel position by comparing the speed information of said wheels with the speed against ground of the vehicle, said step of calculating including the steps of

determining a relational value between the wheel speeds calculated from the rotational speeds of said wheels and the speed against ground of said vehicle; and

determining a correlation between said relational value and information value related to the vehicle, wherein the information value related to said vehicle is the sine of gradient of running road surface, the speed against ground of the vehicle, back-and-forth acceleration, lateral acceleration or a turning radius;

comparing the judgment value of said wheel position with the basis value of the wheel position obtained by preliminarily comparing the speed against ground of said vehicle with the speed information of said wheels at prescribed inner pressure, said step of comparing including a step of comparing said correlation with said correlation at prescribed inner pressure; and

judging decompression of tires based on relation between the comparison value of said basis value with the judgment value and a fixed threshold.

2. A method for detecting decompression of tires based on the rotational speeds of wheels mounted on a vehicle, comprising the steps of:

detecting the rotational speed of each of said wheels;

determining the speed against ground of said vehicle, wherein the speed against ground of said vehicle is determined by signals demodulated from received radio wave of GPS and time;

calculating the speed information of a fixed wheel from the rotational speeds of said wheels;

memorizing the rotational speed of each of the wheels and the speed information of said wheels;

calculating the judgment value of said wheel position by comparing the speed information of said wheels with the speed against ground of the vehicle;

said step of calculating including the steps of

determining the relational value of the wheel speeds calculated from the rotational speeds of the fore-mentioned wheels, wherein the relational value of the speeds of said wheels is the correlative value of the speeds of wheels on a pair of diagonals of a vehicle, the ratio of the speed of wheels at a front axle to that at a rear axle, or difference between them, or the ratio of the speed of left front and rear wheels to that of right front and rear wheels, or difference; and

determining a correlation between said relational value and information value related to the vehicle, wherein the information value related to said vehicle is the sine of gradient of running road surface, the speed against ground of the vehicle, back-and-forth acceleration, lateral acceleration or a turning radius;

comparing the judgment value of said wheel position with the basis value of the wheel position obtained by preliminarily comparing the speed against ground of said vehicle with the speed information of said wheels at prescribed inner pressure said step of comparing including a step of comparing said correlation with said correlation at prescribed inner pressure; and

judging decompression of tires based on relation between the comparison value of said basis value with the judgment value and a fixed threshold.

3. A detection device for detecting decompression of tires based on the rotational speeds of wheels mounted on a vehicle, comprising:

a wheel rotational speed-detecting means for detecting rotational speed of each of said wheels;

a speed against ground of the vehicle-calculating means for determining the speed against ground of the vehicle, wherein the speed against ground of said vehicle is determined by signals demodulated from received radio wave of GPS and time;

a speed information-calculating means for calculating the speed information of a fixed wheel from the rotational speeds of said wheels;

a memory means for memorizing the rotational speed of each of the wheels and the speed information of said wheels;

a judgment value-calculating means for calculating the judgment value of said wheel position by comparing the speed information of said wheels with the speed against ground of the vehicle, said judgment value-calculating means including;

a relational value-calculating means for determining a relational value between the speeds of wheels calculated from the rotational speeds of said wheels and the speed against ground of said vehicle; and

a correlation-calculating means for determining a correlation between said relational value and information value related to the vehicle, wherein the information value related to said vehicle is the sine of gradient of running road surface, the speed against ground of the vehicle, back-and-forth acceleration, lateral acceleration or a turning radius;

a comparison means for comparing the judgment value of said wheel position with the basis value of the wheel position obtained by preliminarily comparing the speed against ground of the vehicle with the speed information of said wheels at prescribed inner pressure, said comparison means including a comparison means for comparing said correlation with said correlation at prescribed inner pressure and including a comparison means for comparing said correlation with said correlation at prescribed inner pressure; and

a reduced means pressure-judging for judging impression of tires based on relation between the comparison value of said basis value with the judgment value and a fixed threshold.

4. A detection device for detecting decompression of tires based on the rotational speeds of wheels mounted on a vehicle, comprising:

a wheel rotational speed-detecting means for detecting rotational speed of each of said wheels;

a speed against ground of the vehicle-calculating means for determining the speed against ground of the vehicle, wherein the speed against ground of said vehicle is determined by signals demodulated from received radio wave of GPS and time;

a speed information-calculating means for calculating the speed information of a fixed wheel from the rotational speeds of said wheels;

a memory means for memorizing the rotational speed of each of the wheels and the speed information of said wheels;

a judgment value-calculating means for calculating the judgment value of said wheel position by comparing the speed information of said wheels with the speed against ground of the vehicle, said judgment value-calculating means including;

a relational value-calculating means for determining the relational value of the speeds of wheels calculated from the rotational speeds of said wheels, wherein the relational value of the speeds of said wheels is the correlative value of the speeds of wheels on a pair of diagonals of a vehicle, the ratio of the speed of wheels at a front axle to that at a rear axle, or difference between them, or the ratio of the speed of left front and rear wheels to that of right front and rear wheels, or difference between them; and

a correlation-calculating means for determining a correlation between said relational value and information value related to the vehicle, wherein the information value related to said vehicle is the sine of gradient of running road surface, the speed against ground of the vehicle, back-and-forth acceleration, lateral acceleration or a turning radius;

a comparison means for comparing the judgment value of said wheel position with the basis value of the wheel position obtained by preliminarily comparing the speed against ground of the vehicle with the speed information of said wheels at prescribed inner pressure, said comparison means including a comparison means for comparing said correlation with said correlation at prescribed inner pressure; and

a reduced means pressure-judging for judging impression of tires based on relation between the comparison value of said basis value with the judgment value and a fixed threshold.

5. A program for judging decompression of tires based on the rotational speeds of wheels mounted on a vehicle, comprising:

a speed information-calculating means for calculating the speed information of a fixed wheel from the rotational speeds of said wheel;

a speed against ground of the vehicle-calculating means for determining the speed against ground of the vehicle, wherein the speed against ground of said vehicle is determined by signals demodulated from received radio wave of GPS and time;

a memory means for memorizing the rotational speed of each of the wheels and the speed information of said wheels;

a judgment value-calculating means for calculating the judgment value of said wheel position by comparing the speed information of said wheels with the speed against ground of the vehicle, said judgment value-calculating means including;

a relational value-calculating means for determining the relational value of the speeds of wheels calculated from the rotational speeds of said wheels and the speed against ground of the vehicle determined; and

a correlation-calculating means for determining a correlation between said relational value and information value related to the vehicle, wherein the information value related to said vehicle is the sine of gradient of running road surface, the speed against ground of the vehicle, back-and-forth acceleration, lateral acceleration or a turning radius;

a comparison means for comparing the judgment value of said wheel position with the basis value of the wheel position obtained by preliminarily comparing the speed against ground of the vehicle with the speed information of said wheels at prescribed inner pressure, said comparison means including a comparison means for comparing said correlation with said correlation at prescribed inner pressure; and

a reduced judging pressure-judging means for decompression of tires based on relation between the comparison value of said basis value with the judgment value and a fixed threshold.

6. A program for judging decompression of tires based on the rotational speeds of wheels mounted on a vehicle, comprising:

a speed information-calculating means for calculating the speed information of a fixed wheel from the rotational speeds of said wheel;

a speed against ground of the vehicle-calculating means for determining the speed against ground of the vehicle, wherein the speed against ground of said vehicle is determined by signals demodulated from received radio wave of GPS and time;

a memory means for memorizing the rotational speed of each of the wheels and the speed information of said wheels;

a judgment value-calculating means for calculating the judgment value of said wheel position by comparing the speed information of said wheels with the speed against ground of the vehicle, said judgment value-calculating means including;

a relational value-calculating means for determining the relational value of the speeds of wheels calculated from the rotational speeds of said wheels, wherein the relational value of the speeds of said wheels is the correlative value of the speeds of wheels on a pair of diagonals of a vehicle, the ratio of the speed of wheels at a front axle to that at a rear axle, or difference between them, or the ratio of the speed of left front and rear wheels to that of right front and rear wheels, or difference between them; and

a correlation-calculating means for determining a correlation between said relational value and the information value related to the vehicle, wherein the information value related to said vehicle is the sine of gradient of running road surface, the speed against ground of the vehicle, back-and-forth acceleration, lateral acceleration or a turning radius;

a comparison means for comparing the judgment value of said wheel position with the basis value of the wheel position obtained by preliminarily comparing the speed against ground of the vehicle with the speed information of said wheels at prescribed inner pressure, said comparison means including a comparison means for comparing said correlation with said correlation at prescribed inner pressure; and

a reduced judging pressure-judging means for decompression of tires based on relation between the comparison value of said basis value with the judgment value and a fixed threshold.