Detection device for decreased tire pressures and method thereof
First Claim
1. A detection device for detecting whether the kind of tires mounted on different wheels of a vehicle differs, the device comprising:
- means for detecting the rotational speeds of wheels mounted on the vehicle;
means for detecting torque applied to driving wheels of the vehicle;
means for calculating the inclination of a first straight line representing the relation between (1) a ratio of the rotational speed of a left front wheel to that of a left rear wheel of the vehicle and (2) torque applied to driving wheels of the vehicle;
means for calculating the inclination of a second straight line representing the relation between (1) a ratio of the rotational speed of a right front wheel to that of a right rear wheel of the vehicle and (2) the torque applied to driving wheels;
means for comparing the inclination of the first straight line with the inclination of the second straight line;
means for comparing a difference or a ratio between the inclinations of the first and second straight lines with predetermined values for a difference or a ratio between the inclinations;
means for determining from the difference or the ratio between the inclinations whether different tires are mounted on left and right sides of the vehicle; and
means for providing an indication of whether different tires are mounted on left and right sides of the vehicle.
1 Assignment
0 Petitions
Accused Products
Abstract
A device, and an analogous method and program, for detecting whether different tires are mounted on the left and right driving wheels of a vehicle and accurately detecting decreased tire pressures. The device detects the rotational speeds of wheels mounted on the vehicle, detects torque applied to driving wheels, and calculates the inclinations of straight lines representing (1) the relation between the rotational speed ratio of the front and rear left side wheels and torque applied to driving wheels and (2) the relation between the rotational speed ratio of the front and rear left side wheels and torque applied to driving wheels. The device compares the inclinations of the lines to detect whether different tires are mounted on the driving wheels. Based on the comparison of the inclinations, the device changes the threshold for judging tire deflation to different values for different tires and tires that are not different.
12 Citations
6 Claims
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1. A detection device for detecting whether the kind of tires mounted on different wheels of a vehicle differs, the device comprising:
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means for detecting the rotational speeds of wheels mounted on the vehicle; means for detecting torque applied to driving wheels of the vehicle; means for calculating the inclination of a first straight line representing the relation between (1) a ratio of the rotational speed of a left front wheel to that of a left rear wheel of the vehicle and (2) torque applied to driving wheels of the vehicle; means for calculating the inclination of a second straight line representing the relation between (1) a ratio of the rotational speed of a right front wheel to that of a right rear wheel of the vehicle and (2) the torque applied to driving wheels; means for comparing the inclination of the first straight line with the inclination of the second straight line; means for comparing a difference or a ratio between the inclinations of the first and second straight lines with predetermined values for a difference or a ratio between the inclinations; means for determining from the difference or the ratio between the inclinations whether different tires are mounted on left and right sides of the vehicle; and means for providing an indication of whether different tires are mounted on left and right sides of the vehicle.
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2. A detection method for detecting whether the kind of tires mounted on different wheels of a vehicle differs, the method comprising the steps of:
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(a) detecting the rotational speeds of wheels mounted on the vehicle; (b) detecting torque applied to driving wheels of the vehicle; (c) calculating the inclination of a first straight line representing the relation between (1) a ratio of the rotational speed of a left front wheel to that of a left rear wheel of the vehicle and (2) torque applied to driving wheels of the vehicle; (d) calculating the inclination of a second straight line representing the relation between (1) a ratio of the rotational speed of a right front wheel to that of a right rear wheel of the vehicle and (2) the torque applied to driving wheels; (e) comparing the inclination of the first straight line with the inclination of the second straight line; (f) comparing a difference or a ratio between the inclinations of the first and second straight lines with predetermined values for a difference or a ratio between the inclinations; (g) determining from step (f) whether different tires are mounted on left and right sides of the vehicle; and (h) providing an indication of the results of step (g).
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3. A detection program provided in a device for detecting whether the kind of tires mounted on different wheels of a vehicle differs, the program, when executed, carrying out a method comprising the steps of:
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(a) detecting the rotational speeds of wheels mounted on the vehicle; (b) detecting torque applied to driving wheels of the vehicle; (c) calculating the inclination of a first straight line representing the relation between (1) a ratio of the rotational speed of a left front wheel to that of a left rear wheel of the vehicle and (2) torque applied to driving wheels of the vehicle; (d) calculating the inclination of a second straight line representing the relation between (1) a ratio of the rotational speed of a right front wheel to that of a right rear wheel of the vehicle and (2) the torque applied to driving wheels; (e) comparing the inclination of the first straight line with the inclination of the second straight line; (f) comparing a difference or a ratio between the inclinations of the first and second straight lines with predetermined values for a difference or a ratio between the inclinations; (g) determining from step (f) whether different tires are mounted on left and right sides of the vehicle; and (h) providing an indication of the results of step (g).
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4. A detection device for detecting decreased tire pressure in tires mounted on wheels of a vehicle, the device comprising:
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means for detecting the rotational speeds of wheels mounted on the vehicle; means for detecting torque applied to driving wheels of the vehicle; means for calculating the inclination of a first straight line representing the relation between (1) a ratio of the rotational speed of a left front wheel to that of a left rear wheel of the vehicle and (2) torque applied to driving wheels of the vehicle; means for calculating the inclination of a second straight line representing the relation between (1) a ratio of the rotational speed of a right front wheel to that of a right rear wheel of the vehicle and (2) the torque applied to driving wheels; means for comparing the inclination of the first straight line with the inclination of the second straight line; means for comparing a difference or a ratio between the inclinations of the first and second straight lines with predetermined values for a difference or a ratio between the inclinations; means for determining from the difference or the ratio between the inclinations whether different tires are mounted on left and right sides of the vehicle; means for making a determination of reduced tire pressure from differences in rotational speeds of wheels mounted on the vehicle; means for comparing the determination of reduced tire pressure with (1) a first threshold value when different tires are determined to be mounted on the left and right sides of the vehicle and (2) a second threshold value when different tires are not determined to be mounted on the left and right sides of the vehicle; and means for providing an indication of reduced tire pressure based on the comparison of the determination of reduced tire pressure with the threshold values.
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5. A detection method for detecting decreased tire pressure in tires mounted on wheels of a vehicle, the method comprising the steps of:
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(a) detecting the rotational speeds of wheels mounted on the vehicle; (b) detecting torque applied to driving wheels of the vehicle; (c) calculating the inclination of a first straight line representing the relation between (1) a ratio of the rotational speed of a left front wheel to that of a left rear wheel of the vehicle and (2) torque applied to driving wheels of the vehicle; (d) calculating the inclination of a second straight line representing the relation between (1) a ratio of the rotational speed of a right front wheel to that of a right rear wheel of the vehicle and (2) the torque applied to driving wheels; (e) comparing the inclination of the first straight line with the inclination of the second straight line; (f) comparing a difference or a ratio between the inclinations of the first and second straight lines with predetermined values for a difference or a ratio between the inclinations; (g) determining from step (f) whether different tires are mounted on left and right sides of the vehicle; (h) making a determination of reduced tire pressure from differences in rotational speeds of wheels mounted on the vehicle; (i) determining reduced tire pressure by comparing the determination of reduced tire pressure with (1) a first threshold value when different tires are determined to be mounted on the left and right sides of the vehicle and (2) a second threshold value when different tires are not determined to be mounted on the left and right sides of the vehicle; and (j) providing an indication of the results of step (i).
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6. A detection program provided in a device for detecting decreased tire pressure in tires mounted on wheels of a vehicle, the program, when executed, carrying out a method comprising the steps of:
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(a) detecting the rotational speeds of wheels mounted on the vehicle; (b) detecting torque applied to driving wheels of the vehicle; (c) calculating the inclination of a first straight line representing the relation between (1) a ratio of the rotational speed of a left front wheel to that of a left rear wheel of the vehicle and (2) torque applied to driving wheels of the vehicle; (d) calculating the inclination of a second straight line representing the relation between (1) a ratio of the rotational speed of a right front wheel to that of a right rear wheel of the vehicle and (2) the torque applied to driving wheels; (e) comparing the inclination of the first straight line with the inclination of the second straight line; (f) comparing a difference or a ratio between the inclinations of the first and second straight lines with predetermined values for a difference or a ratio between the inclinations; (g) determining from step (f) whether different tires are mounted on left and right sides of the vehicle; and (h) making a determination of reduced tire pressure from differences in rotational speeds of wheels mounted on the vehicle; (i) determining reduced tire pressure by comparing the determination of reduced tire pressure with (1) a first threshold value when different tires are determined to be mounted on the left and right sides of the vehicle and (2) a second threshold value when different tires are not determined to be mounted on the left and right sides of the vehicle; and (j) providing an indication of the results of step (i).
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Specification