Method and apparatus for alarming decrease in tire air-pressure and program for alarming decrease in tire air-pressure
First Claim
1. A method for alarming decrease in tire air-pressure in which decrease in tire air-pressure is determined on the basis of rotational velocity information of a wheel of a vehicle and no judgment of decrease in air-pressure is performed when ((sum Fsum of force acting on the driving wheel tires)2=(driving force FD)2+(turning force FT)2≧
- (threshold Fθ
)2) or (driving force FD+coefficient a X lateral directional acceleration AL|≧
threshold Fθ
) is satisfied, comprising;
obtaining respective thresholds for determining whether judgment of decrease in tire air-pressure is to be made or not; and
changing the respective thresholds of the above formulas depending on magnitude of driving torque of the vehicle when the vehicle is performing turning movements.
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Abstract
A method for alarming decrease in tire air-pressure in which decrease in tire air-pressure is determined on the basis of rotational velocity information of a wheel of a vehicle. Respective thresholds for determining whether judgment of decrease in tire air-pressure is to be made or not are changed depending on magnitude of driving torque of the vehicle when the vehicle is performing turning movements. It is possible to improve the detection accuracy without issuing an erroneous alarm even in the case where a large driving force is applied when the vehicle is, for instance, running on a climbing road or when it performs trailer towing.
12 Citations
5 Claims
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1. A method for alarming decrease in tire air-pressure in which decrease in tire air-pressure is determined on the basis of rotational velocity information of a wheel of a vehicle and no judgment of decrease in air-pressure is performed when ((sum Fsum of force acting on the driving wheel tires)2=(driving force FD)2+(turning force FT)2≧
- (threshold Fθ
)2) or (driving force FD+coefficient a X lateral directional acceleration AL|≧
threshold Fθ
) is satisfied, comprising;obtaining respective thresholds for determining whether judgment of decrease in tire air-pressure is to be made or not; and changing the respective thresholds of the above formulas depending on magnitude of driving torque of the vehicle when the vehicle is performing turning movements.
- (threshold Fθ
-
2. An apparatus for alarming decrease in tire air-pressure in which decrease in tire air-pressure is determined on the basis of rotational velocity information of a wheel of a vehicle and no judgment of decrease in air-pressure is performed when ((sum Fsum of force acting on the driving wheel tires)2=(driving force FD)2+(turning force FT)2≧
- (threshold Fθ
)2) or (driving force FD+coefficient a X lateral direction acceleration AL|≧
threshold Fθ
) is satisfied, comprising;velocity detecting means which detect wheel speeds of the respective tires, a judging means which judges decrease in tire air-pressure on the basis of the wheel speeds detected by the velocity detecting means, and an alarming means which issues an alarm when a decrease in tire air-pressure is judged in the judging means, wherein the apparatus further comprises a threshold changing means which changes respective thresholds for determining whether judgment of decrease in tire air-pressure is to be made or not depending on magnitude of driving torque of the vehicle when the vehicle is performing turning movements. - View Dependent Claims (3, 4)
- (threshold Fθ
-
5. A system, comprising:
-
a program embodied in a computer readable medium for issuing an alarm of decrease in tire air-pressure of a vehicle and for not performing judgment of decrease in air-pressure when ((sum Fsum of force acting on the driving wheel tires)2=(driving force FD)2+(turning force FT)2≧
(threshold Fθ
)2) or (driving force FD+coefficient a X lateral directional acceleration AL|≧
threshold Fθ
) is satisfied, said program including;judging means which judges decrease in tire air-pressure on the basis of wheel speeds detected by velocity detecting means, and a threshold changing means which changes respective thresholds for determining whether judgment of decrease in tire air-pressure is to be made or not depending on a magnitude of driving torque of the vehicle when the vehicle is performing turning movements; and means for not performing judgment of decreases in air-pressure when ((sum Fsum of force acting on the driving wheel tires)2=(driving force FD)2++(turning force FT)2≧
(threshold Fθ
)2) or (driving force FD coefficient a X lateral directional acceleration AL|≧
threshold Fθ
) is satisfied.
-
Specification