Method and device for calculating turning radius of vehicle taking load movement thereof into consideration
First Claim
Patent Images
1. A vehicle turning radius calculating method for determining a turning radius of a vehicle having left and right tires, comprising:
- detecting the respective rotational angular velocities of left and right tires;
detecting a lateral acceleration of the vehicle;
detecting the load of the vehicle; and
determining a turning radius of the vehicle, based on the detected rotational angular velocities, by taking into consideration a change in effective rolling radiuses of the tires due to a load movement of the vehicle, includingdetermining a correction factor based on the detected load of the vehicle, andexcluding an influence on the rotational angular velocities, of the change in effective rolling radiuses of the tires due to the load movement of the vehicle, using the determined correction factor and the detected lateral acceleration of the vehicle.
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Abstract
A method of and a device for determining a turning radius of a vehicle, accurately, without being influenced by the load movement of the vehicle, are disclosed. The rotational angular velocities of left and right tires are detected, respectively. The turning radius of the vehicle is determined, based on the detected rotational angular velocity, by taking a change in effective rolling radiuses due to the load movement of the vehicle into consideration.
25 Citations
54 Claims
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1. A vehicle turning radius calculating method for determining a turning radius of a vehicle having left and right tires, comprising:
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detecting the respective rotational angular velocities of left and right tires; detecting a lateral acceleration of the vehicle; detecting the load of the vehicle; and determining a turning radius of the vehicle, based on the detected rotational angular velocities, by taking into consideration a change in effective rolling radiuses of the tires due to a load movement of the vehicle, including determining a correction factor based on the detected load of the vehicle, and excluding an influence on the rotational angular velocities, of the change in effective rolling radiuses of the tires due to the load movement of the vehicle, using the determined correction factor and the detected lateral acceleration of the vehicle. - View Dependent Claims (2, 3)
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4. A vehicle turning radius calculating method for determining a turning radius of a vehicle having left and right tires, comprising:
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detecting rotational angular velocities of respective left and right tires; and determining a turning radius of the vehicle, based on the detected rotational angular velocities, by taking a change in effective rolling radiuses of the tires due to a load movement of the vehicle into consideration, including determining speeds of left and right tires, respectively, by multiplying the detected rotational angular velocities by a constant corresponding to the effective rolling radius of the tire at the time of linear traveling of the vehicle, correcting the speeds of right and left tires so as to exclude the influence on the rotational angular velocities of the change in effective rolling radiuses of the tires due to the load movement of the vehicle, and determining the turning radius of the vehicle based on the corrected speeds of the right and left tires; wherein the correcting the speeds of right and left tires includes calculating the speeds of the respective right and left tires after correction, according to the following equations;
space="preserve" listing-type="equation">V2.sub.3 =(1+β
×
a)×
V1.sub.3
space="preserve" listing-type="equation">V2.sub.4 =(1-β
×
a)×
V1.sub.4where a is a lateral acceleration in the lateral direction of the vehicle, which takes a positive value when directed from the left tire to the right tire and takes a negative value when directed from the right tire to the left tire, and where V23 is the speed of the left tire after correction, V24 is the speed of the right tire after correction, V13 is the speed of the left tire before correction, obtained by the determining speeds, V14 is the speed of the right tire before correction, obtained by the determining speeds, and β
is a correction factor given by the equationβ
=(Q×
H×
α
)/Tw×
100, Q being a load of the vehicle, and H being a height from the ground surface of the tire to a center of gravity of the vehicle, α
being a change rate (%) of the effective rolling radius of the tire to the load, and Tw being a distance between the right and left tires. - View Dependent Claims (5)
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6. A vehicle turning radius calculating method for determining a turning radius of a vehicle having left and right tires, comprising:
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detecting rotational angular velocities of the respective left and right tires; and determining a turning radius of the vehicle, based on the detected rotational angular velocities, by taking into consideration a change in effective rolling radiuses of the tires due to a load movement of the vehicle, including determining a first vehicle turning radius R'"'"' in which the influence of the load movement of the vehicle is not taken into consideration, based on the detected rotational angular velocities, and determining a second vehicle turning radius R by correcting the first vehicle turning radius R'"'"' taking into consideration the influence of the change in effective rolling radiuses due to the load movement of the vehicle. - View Dependent Claims (7, 8, 9, 10, 11)
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12. A vehicle turning radius calculating method for determining a turning radius of a vehicle having left and right tires, comprising:
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detecting rotational angular velocities of the respective left and right tires; and determining a turning radius of the vehicle, based on the detected rotational angular velocities, by taking into consideration a change in effective rolling radiuses of the tires due to a load movement of the vehicle, including correcting the detected rotational angular velocities of the respective right and left tires so as to exclude the influence on the rotational angular velocities of the change in effective rolling radiuses of the tires due to the load movement of the vehicle, and determining the turning radius of the vehicle based on the corrected rotational angular velocities of the right and left tires; wherein the correcting the detected rotational angular velocities includes calculating the rotational angular velocities of right and left tires after correction, F33 and F34, according to the following equations;
space="preserve" listing-type="equation">F3.sub.3 =(1+β
×
a)×
F1.sub.3
space="preserve" listing-type="equation">F3.sub.4 =(1-β
×
a)×
F1.sub.4where a is a lateral acceleration in a lateral direction of the vehicle, which takes a positive value when directed from the left tire to the right tire and takes a negative value when directed from the right tire to the left tire, F33 is a rotational angular velocity of the left tire after correction, F13 is a rotational angular velocity of the left tire before correction, obtained by the detecting rotational angular velocities, F34 is a rotational angular velocity of the right tire after correction, F14 is a rotational angular velocity of the right tire before correction, obtained by the detecting rotational angular velocities, and β
is a correction factor given by the equationβ
=(Q×
H×
α
)/Tw×
100, Q being a load of the vehicle, H being a height from the ground surface of the tire to a center of gravity of the vehicle, α
being a change rate (%) of the effective rolling radius of the tire to the load, and Tw being a distance between the right and left tires. - View Dependent Claims (13)
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14. A tire pressure drop detecting method, comprising:
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determining a turning radius of a vehicle having left and right tires, during a turn, including detecting rotational angular velocities of the respective left and right tires; and determining the turning radius of the vehicle, based on the detected rotational angular velocities, by taking into consideration a change in effective rolling radiuses of the tires due to a load movement of the vehicle, so that the influence on the determined turning radius of the vehicle of the changes in effective rolling radiuses of the tires due to the load movement of the vehicle, is excluded; correcting the detected rotational angular velocities using the determined turning radius of the vehicle, in which the influence of changes in effective rolling radiuses of the tires due to the load movement of the vehicle is excluded, to determine rotational angular velocities in which scatter thereof, caused by a difference in turning radius as between inner and outer wheels of the vehicle during the turn, is excluded; judging whether the determined turning radius of the vehicle is larger than a predetermined value or not; determining whether a pneumatic pressure of any tire of the vehicle drops or not, if the determined turning radius of the vehicle is larger than the predetermined value; and inhibiting the tire pressure drop detection if the determined turning radius of the vehicle is smaller than the predetermined value; wherein the detecting whether a pneumatic pressure of any tire drops or not includes judging whether the pneumatic pressure of any tire drops or not, based on the corrected rotational angular velocities. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27)
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28. A turning radius calculating device for determining a turning radius of a vehicle having left and right tires, comprising:
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rotational angular velocity detecting means for detecting rotational angular velocities of the respective left and right tires; turning radius determining means for determining the turning radius of the vehicle, based on the rotational angular velocities detected by the rotational angular velocity detecting means, by taking into consideration a change in effective rolling radiuses of the tires due to a load movement of the vehicle; lateral acceleration detecting means for detecting a lateral acceleration of the vehicle; and load detecting means for detecting a load of the vehicle; wherein the turning radius determining means includes correction factor determining means for determining a correction factor based on the load of the vehicle detected by the load detecting means, means for excluding from the determination of the turning radius the influence on the rotational angular velocities of the change in effective rolling radiuses of the tires due to the load movement of the vehicle, using the correction factor determined by the correction factor determining means and the lateral acceleration detected by the lateral acceleration detecting means. - View Dependent Claims (29, 30)
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31. A turning radius calculating device for determining a turning radius of a vehicle having left and right tires, comprising:
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rotational angular velocity detecting means for detecting rotational angular velocities of the respective left and right tires; and turning radius determining means for determining the turning radius of the vehicle, based on the rotational angular velocities detected by the rotational angular velocity detecting means, by taking into consideration a change in effective rolling radiuses of the tires due to a load movement of the vehicle; wherein the turning radius determining means includes means for determining speeds of the respective left and right tires, by multiplying the detected rotational angular velocities by a constant corresponding to the effective rolling radius of the tire at a time of linear traveling of the vehicle, means for correcting the speeds of the respective right and left tires so as to exclude the influence on the rotational angular velocities, of the change in effective rolling radiuses of the tires due to the load movement of the vehicle, and means for determining the turning radius of the vehicle based on the corrected speeds of the respective right and left tires; and wherein the means for correcting the speeds of the respective right and left tires includes means for finding the speeds after correction of the respective right and left tires, according to the following equations;
space="preserve" listing-type="equation">V2.sub.3 -(1+β
×
a)×
V1.sub.3
space="preserve" listing-type="equation">V2.sub.4 =(1-β
×
a)×
V1.sub.4,where a is a lateral acceleration at the lateral direction of the vehicle, which takes a positive value when directed from the left tire to the right tire and takes a negative value when directed from the right tire to the left tire, V23 is a speed of the left tire after correction, V24 is a speed of the right tire after correction, V13 is a speed of the left tire before correction, obtained by the speeds determining means, V14 is a speed of the right tire before correction, obtained by the speeds determining means, and β
is a correction factor given by the equationβ
=(Q×
H×
α
)/Tw×
100, Q being a load of the vehicle, H being a height from the ground surface of the tire to a center of gravity of the vehicle, α
being a change rate (%) of the effective rolling radius of the tire to the load, and Tw being a distance between the right and left tires. - View Dependent Claims (32)
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33. A turning radius calculating device for determining a turning radius of a vehicle having left and right tires, comprising:
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rotational angular velocity detecting means for detecting rotational angular velocities of the respective left and right tires; and turning radius determining means for determining the turning radius of the vehicle based on the rotational angular velocities detected by the rotational angular velocity detecting means, by taking into consideration a change in effective rolling radiuses of the tires due to a load movement of the vehicle, wherein the turning radius determining means includes means for determining a first vehicle turning radius R'"'"' without consideration of the influence of the load movement of the vehicle, based on the rotational angular velocities detected by the rotational angular velocity detecting means, and means for determining a second vehicle turning radius R by correcting the determined first vehicle turning radius R'"'"', taking into consideration the influence of the change in effective rolling radiuses due to the load movement of the vehicle. - View Dependent Claims (34, 35, 36, 37, 38)
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39. A turning radius calculating device for determining a turning radius of a vehicle having left and right tires, comprising:
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rotational angular velocity detecting means for detecting rotational angular velocities of the respective left and right tires, and turning radius determining means for determining the turning radius of the vehicle based on the rotational angular velocities detected by the rotational angular velocity detecting means, by taking into consideration a change in effective rolling radiuses of the tires due to a load movement of the vehicle, the turning radius determining means including means for correcting the rotational angular velocities of the respective right and left tires detected by the rotational angular velocity detecting means so as to exclude the influence on the rotational angular velocities, of the change in effective rolling radiuses of the tires due to the load movement of the vehicle, and means for determining the turning radius of the vehicle based on the corrected rotational angular velocities of the right and left tires; wherein the means for correcting the detected rotational angular velocities calculates the corrected rotational angular velocities of the right and left tires according to the following equations;
space="preserve" listing-type="equation">F3.sub.3 =(1+β
×
a)×
F1.sub.3
space="preserve" listing-type="equation">F3.sub.4 =(1-β
×
a)×
F1.sub.4where a is a lateral acceleration in a lateral direction of the vehicle, which takes a positive value when directed from the left tire to the right tire and takes a negative value when directed from the right tire to the left tire, F33 is a rotational angular velocity of the left tire after correction, F13 is a rotational angular velocity of the left tire before correction, obtained by the rotational angular velocity detecting means, F34 is a rotational angular velocity of the right tire after correction, F14 is a rotational angular velocity of the right tire before correction, obtained by the rotational angular velocity detecting means, and β
is a correction factor given by the equationβ
=(Q×
H×
α
)/Tw×
100, Q being a load of the vehicle, H being a height from the ground surface of the tire to a center of gravity of the vehicle, α
being a change rate (%) of the effective rolling radius of the tire to the load, and Tw being a distance between the right and left tires. - View Dependent Claims (40)
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41. A tire pressure drop detecting device, comprising:
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a vehicle turning radius calculating device for determining a turning radius of a vehicle having left and right tires, during a turn, including rotational angular velocity detecting means for detecting rotational angular velocities of the respective left and right tires, and turning radius determining means for determining the turning radius of the vehicle, based on the rotational angular velocities detected by the rotational angular velocity detecting means, by taking into consideration a change in effective rolling radiuses of the tires due to a load movement of the vehicle; means for judging whether the turning radius of the vehicle determined by the vehicle turning radius calculating device is larger than a predetermined value or not; pneumatic pressure drop determining means for determining, when the turning radius of the vehicle is larger than the predetermined value, whether or not a pneumatic pressure of any tire of the vehicle drops; means for inhibiting the detection of the tire pressure drop when the turning radius of the vehicle is smaller than the predetermined value; and means for correcting the detected rotational angular velocities using the turning radius of the vehicle, in which the influence of changes in effective rolling radiuses of the tires due to the load movement of the vehicle is excluded, thereby to determine corrected rotational angular velocities in which scatter of the rotational angular velocities between the left and right tires, caused by a difference in turning radius as between inner and outer wheels of the vehicle during the turn, is corrected; wherein the pneumatic pressure drop determining means determines whether or not the pneumatic pressure of any tire of the vehicle drops, based on the corrected rotational angular velocities. - View Dependent Claims (42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54)
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Specification