KR101592520B1 - Device for measuring tire pressure and method thereof, recording medium for performing the method - Google Patents

Abstract

The present invention provides a device and a method for measuring the air pressure of a tire and a recording medium for performing the same. The device for measuring the air pressure of a tire transmits an ultrasonic wave to the tire, receives an ultrasonic wave reflected on the surface of the tire and an inner rim of the tire to detect a reception time of the ultrasonic wave reflected on the surface of the tire and the inner rim of the tire, and calculates the difference in values of the detected reception time of the ultrasonic wave reflected on the surface of the tire and the inner rim of the tire to detect the air pressure of the tire in accordance with the calculated difference value of the reception time. Furthermore, the temperature of the tire is measured to calculate a transmission speed of the ultrasonic wave depending on the temperature of the tire. An increase or decrease in the reception time depending on the calculated transmission speed is calculated to correct the reception time of the ultrasonic wave reflected on the inner rim of the tire. The air pressure of the tire is detected depending on the difference value between the corrected reception time and the reception time of the ultrasonic wave reflected on the surface of the tire.

Description

TECHNICAL FIELD [0001] The present invention relates to a tire air pressure measuring apparatus and method, and a recording medium for performing the same. BACKGROUND OF THE INVENTION 1. Field of the Invention [0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and a method for measuring tire air pressure, and a recording medium for performing the same, and more particularly to a tire air pressure measuring apparatus and method for measuring an air pressure of a tire by an indirect method using an ultrasonic sensor, Media.

In general, if the air pressure of a car tire is too high or low, it is likely that the tire will blow or the vehicle will slip easily, leading to a major accident. In addition, when the air pressure of the automobile tire is low, fuel consumption is increased, fuel economy is deteriorated, the life of the tire is shortened, and when the air pressure of the automobile tire is high, the ride comfort and braking force are affected.

In recent years, TPMS (Tire Pressure Monitoring System) has become mandatory for automobiles worldwide to prevent accidents caused by abnormal tire pressure.

The method of measuring the air pressure of such an automobile tire is a direct method or an indirect method. In the direct method, a pressure sensor and a temperature sensor are installed inside the tire to measure the tire air pressure. The indirect method measures the wheel speed or wheel speed The air pressure of the tire is measured.

However, the direct method of measuring the air pressure by inserting the pressure sensor and the temperature sensor inside the tire can know the exact pressure value, but there is a disadvantage that the maintenance cost is incurred due to the replacement of the battery due to the problem of the battery use period of the pressure sensor and the temperature sensor The indirect method of measuring the tire pressure or the tire speed by analyzing the spectrum of the wheel speed or the wheel speed of the automobile has a problem that the error of each wheel speed occurs or the resolution of the wheel speed is low so that the accurate pressure value can not be known.

Therefore, a new indirect tire pressure measurement method using an ultrasonic sensor that requires no maintenance cost at a low cost of an indirect method while using a direct tire pressure measurement method is required.

KR 10-2013-0081095 A

One aspect of the present invention is a method of transmitting ultrasonic waves to an automobile tire to receive ultrasonic waves reflected from the tire surface and a tire inner rim and to detect a difference in reception time of ultrasonic waves reflected on the tire surface and a tire inner rim A tire air pressure measuring device and method for measuring the tire air pressure according to the present invention, and a recording medium for performing the same.

According to an aspect of the present invention, there is provided a tire air pressure measuring apparatus for measuring an air pressure of a tire using an ultrasonic sensor, the apparatus comprising: an ultrasonic transmitter mounted on an outer surface of the tire for transmitting an ultrasonic wave to the tire; An ultrasonic receiver for receiving ultrasonic waves reflected from the outside and inside of the tire, and a controller for detecting the air pressure of the tire according to the reception time of ultrasonic waves reflected from outside and inside of the tire.

Wherein the ultrasonic wave receiving unit receives ultrasonic waves reflected from the surface of the tire by the ultrasonic wave transmitted from the ultrasonic wave transmitting unit and transmits ultrasonic waves transmitted from the ultrasonic wave transmitting unit through the surface of the tire and reflected by the inner rim of the tire Lt; / RTI >

The receiving of the ultrasonic waves reflected on the inner rim of the tire is performed by receiving an ultrasonic wave transmitted through the surface of the tire and having the transmission speed changed by the internal air pressure of the tire reflected on the inner rim of the tire .

Wherein the control unit measures a reception time of ultrasonic waves reflected from the outside and inside of the tire and measures a reception time of ultrasonic waves reflected from the surface of the tire by the ultrasonic waves transmitted from the ultrasonic transmission unit and a reception time of ultrasonic waves reflected from the inside rim of the tire And a reception time calculating unit for calculating a time difference of the reception time of the reflected ultrasonic waves.

The control unit may include an air pressure detecting unit that compares the calculated time difference with previously stored air pressure data and detects an air pressure of the tire corresponding to the time difference.

The control unit measures the temperature of the tire, calculates a transmission speed of the ultrasonic wave that varies according to the temperature of the tire, and calculates a reception time that decreases or increases according to the changed transmission speed of the ultrasonic wave to the inside rim of the tire And a reception time correction unit for adding or subtracting the reception time of the reflected ultrasonic waves to correct the reception time of the ultrasonic waves reflected on the inner rim of the tire.

Wherein the controller calculates a corrected time difference between the reception time of the ultrasonic waves reflected on the corrected inner rim of the tire and the reception time of the ultrasonic waves reflected on the surface of the tire, The air pressure of the tire corresponding to the corrected time difference can be detected.

The temperature of the tire is measured in a front fender and a rear fender of the vehicle and the temperature of the tire can be measured through an infrared sensor for measuring the surface temperature of the tire.

The ultrasonic wave receiving unit and the ultrasonic wave transmitting unit may be formed in a front fender and a rear fender of the vehicle.

And outputting the detected air pressure information of the tire to an output device provided inside the vehicle or an output device provided outside the vehicle.

Another aspect of the present invention is a method for transmitting ultrasonic waves to a tire of a vehicle to receive ultrasonic waves reflected from the surface of the tire and the inner rim of the tire, the air pressure of the tire is detected according to the reception time of the ultrasonic waves reflected on the rim.

The detection of the air pressure of the tire in accordance with the time of receiving the ultrasonic waves reflected on the surface of the tire and the inner rim of the tire may include detecting the time of receiving ultrasonic waves reflected on the surface of the tire and the inner rim of the tire the air pressure corresponding to the calculated time difference can be detected by comparing the calculated time difference with the previously stored air pressure data.

Detecting the air pressure of the tire according to the receiving time of the ultrasonic waves reflected on the surface of the tire and the inner rim of the tire is performed by measuring the surface temperature of the tire and measuring the surface temperature of the ultrasonic wave And calculating the transmission speed and detecting the air pressure of the tire by correcting the reception time of the ultrasonic waves reflected on the inner rim of the tire according to the calculated transmission speed.

The method of detecting the air pressure of the tire by correcting the reception time of the ultrasonic waves reflected on the inner rim of the tire according to the transmission speed of the ultrasonic wave is characterized in that the reception time is reduced or increased according to the calculated transmission speed, and detecting the air pressure of the tire by adding or subtracting it to the reception time of the ultrasonic waves reflected on the rim.

And comparing the detected air pressure of the tire with a predetermined reference air pressure to detect whether or not the tire is normal.

The detecting whether the tire is normal may further include outputting a warning signal when the detected air pressure of the tire is less than the predetermined reference air pressure.

And may be a computer-readable recording medium on which a computer program is recorded, for executing the control method of the tire air pressure measurement apparatus.

According to one aspect of the present invention, an apparatus for measuring tire air pressure receives ultrasonic waves reflected from a tire surface and a tire inner rim by transmitting an ultrasonic wave to an automobile tire, and transmits the ultrasonic waves to a tire surface and a tire inner rim The air pressure of the tire can be measured according to the difference in the reception time of the reflected ultrasonic waves.

According to another aspect of the present invention, there is provided a method for measuring a temperature of a tire, the method comprising: measuring a temperature of the tire, calculating a transmission speed of the ultrasonic wave that varies according to the temperature of the tire, The air pressure of the tire can be measured by correcting the reception time of the ultrasonic waves reflected on the inner rim of the tire which changes according to the temperature of the tire by adding or subtracting it to the reception time of the reflected ultrasonic waves.

1 is a conceptual diagram of an apparatus for measuring tire pressure according to an embodiment of the present invention.
2 is a block diagram of the air pressure measuring apparatus shown in Fig.
3 is a view showing the characteristics of ultrasonic waves.
FIG. 4 is a diagram illustrating an example of the ultrasonic transmitter and the ultrasonic receiver shown in FIG. 2. FIG.
FIG. 5 is a diagram illustrating an example of the ultrasonic transmitter and the ultrasonic receiver shown in FIG. 2. FIG.
6 is a view showing a temperature measuring unit according to another embodiment of the present invention.
7 is a flowchart illustrating a method of controlling a tire air pressure measurement apparatus according to an embodiment of the present invention.
8 is a flowchart showing a control method of a tire air pressure measuring apparatus according to another embodiment of the present invention.
9 is a flowchart showing a control method of a tire air pressure measuring apparatus according to another embodiment of the present invention.

The following detailed description of the invention refers to the accompanying drawings, which illustrate, by way of illustration, specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. It should be understood that the various embodiments of the present invention are different, but need not be mutually exclusive. For example, certain features, structures, and characteristics described herein may be implemented in other embodiments without departing from the spirit and scope of the invention in connection with an embodiment. It is also to be understood that the position or arrangement of the individual components within each disclosed embodiment may be varied without departing from the spirit and scope of the invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is to be limited only by the appended claims, along with the full scope of equivalents to which such claims are entitled, if properly explained. In the drawings, like reference numerals refer to the same or similar functions throughout the several views.

Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the drawings.

FIG. 1 is a conceptual diagram of a tire air pressure measuring apparatus according to an embodiment of the present invention, FIG. 2 is a block diagram of the air pressure measuring apparatus shown in FIG. 1, FIG. 3 is a diagram showing characteristics of an ultrasonic wave, FIG. 4 is a diagram illustrating an example of the ultrasonic transmission unit and the ultrasonic reception unit shown in FIG. 2. FIG. 5 is a diagram illustrating an example of the ultrasonic transmission unit and the ultrasonic reception unit shown in FIG. 2. FIG. 1 is a view showing a temperature measuring unit according to an example.

1, an apparatus 100 for measuring tire pressure according to an embodiment of the present invention includes a tire 10 having a side (e.g., a fender 40) of a vehicle 10 capable of transmitting and receiving ultrasound to and from a tire 20, And the ultrasonic wave is transmitted to the tire 20 and the ultrasonic wave reflected from the tire 20 is received to measure the air pressure of the tire 20. [

Specifically, the tire air pressure measurement apparatus 100 measures the reception time of ultrasonic waves reflected from the outside and inside of the tire 20, and measures the air pressure of the tire 20 according to the measured reception time.

2, the tire air pressure measurement apparatus 100 may include an ultrasonic transmission unit 110, an ultrasonic reception unit 120, a control unit 130, and a memory unit 140. 2 shows a tire pressure measurement apparatus 100 having various components. However, not all illustrated components are required. The tire air pressure measurement apparatus 100 can be implemented by a larger number of components than the illustrated components, and the tire air pressure measurement apparatus 100 can be implemented by fewer components. Hereinafter, the above-mentioned components will be described in detail.

The ultrasonic transmission unit 110 can transmit ultrasonic waves to the tire 20. The ultrasonic transmission unit 110 may be provided in a fender 40 of the vehicle 10. The ultrasonic transmission unit 110 may output ultrasonic waves to transmit the ultrasonic waves in the vertical direction to the tire 20 and may adjust the angles so that the ultrasonic waves reflected by the tire 20 may be received by the ultrasonic reception unit 120, Can be transmitted.

At this time, the ultrasonic wave has a characteristic of being reflected, refracted or transmitted when it is hit against the tire 20. Referring to FIG. 3, the ultrasonic wave may be reflected or refracted when a resistance to a sound wave is struck against a boundary surface of another medium, and may be transmitted to another medium. A part of the ultrasonic waves transmitted to the tire 20 from the ultrasonic transmission unit 110 can be reflected on the surface of the tire 20 and a part of the ultrasonic waves can be transmitted through the tire 20 to enter the interior of the tire 20 At this time, the ultrasonic waves that have entered the tire 20 can be reflected to the rim 30 inside the tire 20. [

In addition, the ultrasonic transmission unit 110 can periodically transmit ultrasonic waves, transmit ultrasonic waves when receiving a transmission signal from the control unit 130, and transmit ultrasonic waves when receiving an ultrasonic transmission signal by a user's operation .

The ultrasonic receiving unit 120 can receive ultrasonic waves reflected from the outside and the inside of the tire 20. The ultrasonic waves reflected from the inside of the tire 20 may be reflected by the inner rim 30 of the tire 20, As shown in FIG.

Referring to FIG. 4, the ultrasound receiving unit 120 may receive ultrasonic waves reflected from the surface of the tire 20. At this time, the ultrasonic waves reflected on the surface of the tire 20 may be reflected from the outside of the tire, that is, air having a constant pressure at atmospheric pressure (0.1 kPa). Since the ultrasonic waves reflected on the surface of the tire 20 are reflected in the air, there is no change in the ultrasonic transmission speed due to the pressure.

Referring to FIG. 5, the ultrasound receiving unit 120 may receive ultrasound reflected from the rim 30 of the tire 20. At this time, ultrasonic waves reflected on the inner rim 30 of the tire 20 can transmit through the surface of the tire 20, and the transmission speed can be changed by the internal pressure of the tire 20. The inside of the tire 20 may be densely packed by pressure, and the transmission speed of the ultrasonic wave may be accelerated in a dense air-density region due to the transmission characteristics of sound waves depending on the density of the medium.

The ultrasound receiving unit 120 may transmit an ultrasound reception signal to the controller 130 upon receiving the ultrasound.

When receiving the ultrasonic reception signal from the ultrasonic reception unit 120, the control unit 130 detects the time when the ultrasonic waves are received and detects the air pressure of the tire 20 according to the reception time information.

The control unit 130 may include a reception time calculating unit 131, a reception time correction unit 132, and an air pressure detection unit 133.

The reception time calculating unit 131 can detect the time when the ultrasonic wave is received when receiving the ultrasonic reception signal from the ultrasonic reception unit 120. [ The reception time calculating unit 131 detects the reception time of the ultrasonic waves reflected from the surface of the tire 20 and the rim 30 inside the tire 20 received from the ultrasonic receiver 120, The reception time difference value between the reception time of the ultrasonic waves reflected on the surface and the reception time of the ultrasonic waves reflected on the inner rim 30 of the tire 20 can be calculated.

The ultrasonic waves reflected on the inner rim 30 of the tire 20 reach the surface of the tire 20 and then transmitted through the surface of the tire 20 to the rim 30 inside the tire 20 The ultrasonic waves reflected from the surface of the tire 20 reach the rim 30 from the surface of the tire 20 by the time taken to reach the surface of the tire 20 from the rim 30 The receiving time may be long. The reception time difference value between the reception time of the ultrasonic waves reflected by the surface of the tire 20 and the reception time of the ultrasonic waves reflected by the inner rim 30 of the tire 20 is set to be the rim , 30) to reach the surface of the tire 20 from the rim 30.

The time can be counted from the time when the ultrasonic wave is transmitted to the tire 20 by the ultrasonic transmission unit 110 and the time of reception of ultrasonic waves reflected on the surface of the tire 20 and the rim 30 inside the tire 20 May refer to the time from when the ultrasonic wave is transmitted from the ultrasonic transmission unit 110 to when the ultrasonic reception signal is received by the reception time calculation unit 131. [

On the other hand, the ultrasonic waves transmitted from inside the tire 20 (from the surface of the tire 20 to the rim 30, from the rim 30 to the surface of the tire 20) The transmission speed may vary depending on the internal pressure. For example, when the pressure inside the tire 20 is high, the density of the inside of the tire 20 is increased by the pressure, so that the transmission speed of the ultrasonic wave can be increased. When the pressure inside the tire 20 is low, The internal density may be lowered and the transmission speed may be slowed down.

The air pressure detecting section 133 can detect the air pressure of the tire 20 in accordance with the reception time difference value information calculated by the reception time calculating section 131. [ The air pressure detecting unit 133 can detect the air pressure of the tire 20 in accordance with the reception time difference value which decreases or increases according to the change of the transmission speed of the ultrasonic wave in accordance with the pressure inside the tire 20, .

Specifically, the air pressure detector 133 receives information on the reception time difference value from the reception time calculator 131, and compares the reception time difference value with the air pressure data stored in the memory unit 140 in advance. The air pressure detector 133 can compare the reception time difference value with the air pressure data stored in advance in the memory unit 140 and detect the air pressure of the tire 20 corresponding to the reception time difference value.

At this time, the air pressure data stored in advance in the memory unit 140 may mean data classified into air pressure according to the reception time difference value.

The tire air pressure measuring apparatus 100 according to another embodiment of the present invention can detect the air pressure of the tire 20 by reflecting the temperature of the tire 20 which changes according to weather, temperature of the ground surface, friction with the ground, .

At this time, the air pressure of the tire 20 is detected by reflecting the temperature of the tire 20, except for the ultrasonic transmission characteristics that vary with temperature, So as to detect the air pressure of the tire 20 accurately by detecting the air pressure of the tire 20.

The reception time correction unit 132 may correct the reception time of the ultrasonic waves reflected on the inner rim 30 of the tire 20 by reflecting the change in the transmission speed of the ultrasonic waves according to the temperature of the tire 20 .

Specifically, the reception time correction unit 132 can measure the temperature of the tire 20 which changes in accordance with weather, ground temperature, friction with the ground, and the like. At this time, the temperature of the tire 20 can be measured by the infrared sensor 150. 6, the infrared sensor 150 may be installed on one side (e.g., a fender 40) of the automobile 10 capable of measuring the temperature of the tire 20, The surface temperature can be measured.

At this time, the internal temperature of the tire 20 can be predicted by the temperature of the surface of the tire 20 measured. The heat energy inside the tire 20 can be exchanged with heat until it reaches thermal parallelism with the rubber surrounding the surface of the tire 20 by the second law of thermodynamics. The temperature inside the tire 20 and the surface temperature of the tire 20 can be equal to each other and thus the temperature inside the tire 20 can be predicted by measuring the temperature of the surface of the tire 20. [

On the other hand, a method of measuring the temperature of the surface of the tire 20 is a method of measuring by using an outside light sensor using an infrared sensor. It is needless to say that another method can be applied.

The reception time correction unit 132 can calculate the transmission speed of the ultrasonic wave which changes according to the measured temperature of the tire 20. [ At this time, the transmission speed of the ultrasonic wave, which changes according to the temperature of the tire 20, can be calculated through Equation 1, which is a formula for calculating the transmission speed of the sound wave according to the temperature.

)을 산출할 수 있다. 수신 시간 보정부(132)는 산출한 전송 속도에 따라 줄어들거나 늘어나는 시간(

)을 타이어(20) 내부 림(rim, 30)에 반사되는 초음파의 수신 시간에 감산 또는 가산하여 타이어(20) 내부 림(rim, 30)에 반사되는 초음파의 수신 시간을 보정할 수 있다.The reception time correcting unit 132 compares the reception time when the temperature of the tire 20 is lower than the transmission speed of the ultrasonic wave at room temperature (20 DEG C)

) Can be calculated. The reception time correcting unit 132 calculates the reception time (time)

To the reception time of the ultrasonic waves reflected on the inner rim 30 of the tire 20 so as to correct the reception time of the ultrasonic waves reflected on the inner rim 30 of the tire 20.

)은 0.05㎲로 산출될 수 있다. 이러한 타이어(20) 온도에 따라 줄어든 시간(

)인 0.05㎲을 타이어(20) 내부 림(rim, 30)에 반사되는 초음파의 수신 시간에 가산함으로써, 타이어(20) 내부 림(rim, 30)에 반사되는 초음파의 수신 시간을 보정할 수 있다.For example, when the room temperature is 20 占 폚 and the internal temperature of the tire 20 is 70 占 폚, the ultrasonic transmission rate at room temperature (20 占 폚) is 343 m / s according to the formula (1) The ultrasonic transmission speed is 374 m / s. The distance from the surface of the tire 20 to the inner rim 30 of the tire 20 is about 0.2 m and the distance from the surface of the tire 20 to the ultrasonic transmitting unit 110 or the ultrasonic receiving unit 120 is 0.1 m, the reception time of the ultrasonic waves when the internal temperature of the tire 20 is at room temperature (20 ° C) is 1.7 占 퐏, and the reception time of ultrasonic waves at 70 占 폚 is 1.65 占 퐏. Accordingly, the time that is reduced according to the temperature of the tire 20

) Can be calculated as 0.05 mu s. The time that is reduced by the temperature of the tire 20

The reception time of the ultrasonic waves reflected on the inner rim 30 of the tire 20 can be corrected by adding 0.05 占 퐏 to the reception time of the ultrasonic waves reflected on the inner rim 30 of the tire 20 .

The control unit 130 can control the air pressure information of the tire 20 detected in the above-described manner to be output to an output device (not shown) provided in the vehicle 10, It is possible to transmit the detected air pressure information of the tire 20 via wireless communication so that the information is outputted to an output device (not shown) outside the vehicle 10. [

Further, the control unit 130 can compare the air pressure of the tire 20 detected in the above-described manner with a predetermined reference air pressure. The controller 130 controls the output device (not shown) provided inside the automobile 10 or the output device (not shown) provided outside the automobile 10 when the detected air pressure of the tire 20 is less than the predetermined reference air pressure, To output a warning signal.

The memory unit 140 may store the air pressure data in which the tire air pressure information is classified according to the ultrasonic reception time difference value.

Hereinafter, a method of controlling the tire inflation pressure measuring apparatus according to an embodiment of the present invention will be described with reference to FIG.

First, ultrasonic waves are transmitted to the tire 20 (210).

At this time, the ultrasonic waves transmitted to the tire 20 can be transmitted by adjusting the angle so that the ultrasonic waves reflected by the tire 20 can be received by the ultrasonic receiver 120.

Ultrasonic waves reflected on the tire 20 surface and the inner rim 30 of the tire 20 are received (220).

At this time, the ultrasonic waves transmitted to the tire 20 are transmitted to the surface of the tire 20 and the inside of the tire 20 due to the properties of reflection and transmission of the ultrasonic waves, and reflected by the rim 30 inside the tire 20 .

The detection time of ultrasonic waves reflected on the surface of the tire 20 and the inner rim 30 of the tire 20 is detected 230 and the detected surface of the tire 20 and the inner rim of the tire 20 are detected, 30) of the ultrasonic waves reflected by the ultrasonic waves is calculated (240).

At this time, the time can be counted from the time when the ultrasonic transmission unit 110 transmits the ultrasonic waves to the tire 20, and the time of reception of the ultrasonic waves reflected on the surface of the tire 20 and the inner rim 30 of the tire 20 May mean the time from when the ultrasonic wave is transmitted from the ultrasonic transmission unit 110 to when the ultrasonic reception signal is received by the control unit 130. [

The air pressure of the tire 20 corresponding to the difference value calculated by matching with the calculated difference value and the air pressure data stored in advance in the memory unit 140 is detected (250).

Hereinafter, a control method of the tire inflation pressure measuring apparatus according to another embodiment of the present invention will be described with reference to FIG.

The tire air pressure measuring apparatus according to another embodiment of the present invention can detect the air pressure of the tire 20 by reflecting the temperature of the tire 20. [

An ultrasonic wave is transmitted 310 to the tire 20 and ultrasonic waves reflected on the tire 20 surface and the inner rim 30 of the tire 20 are received 320.

In addition, the time when ultrasonic waves reflected on the surface of the tire 20 and the inner rim 30 of the tire 20 are received is detected (330).

The temperature of the tire 20 is measured 340 using an infrared sensor provided in the fender 40 of the automobile 10 and the transmission speed of the ultrasonic wave according to the temperature of the measured tire 20 is calculated 350).

)을 산출한다(360).Further, it is possible to reduce the reception time (or decrease) of the ultrasonic wave in accordance with the transmission speed of the ultrasonic wave,

(360).

)은 타이어(20)의 외부, 즉 실온(20℃)에서의 초음파의 전송 속도에 따른 수신 시간과 타이어(20) 온도에서의 초음파의 전송 속도에 따른 수신 시간의 차이값을 의미할 수 있다.At this time, depending on the transmission speed of the ultrasonic wave which changes according to the temperature of the tire 20,

May mean the difference between the reception time according to the transmission speed of the ultrasonic wave at the room temperature (20 캜) and the reception time according to the transmission speed of the ultrasonic wave at the temperature of the tire 20, outside the tire 20.

)을 타이어(20) 내부 림(rim, 30)에 반사되는 초음파의 수신 시간에 가산 또는 감산한다(370).Also, the calculated reception time (

(370) to the reception time of ultrasonic waves reflected on the inner rim (30) of the tire (20).

)을 타이어(20) 내부 림(rim, 30)에 반사되는 초음파의 수신 시간에 가산 또는 감산한 초음파의 수신 시간과의 차이값을 산출한다(380).Further, the reception time of ultrasonic waves reflected from the surface of the tire 20 and the calculated reception time (

Of the ultrasonic wave reflected by the inner rim 30 of the tire 20 is added to or subtracted from the reception time of the ultrasonic wave reflected by the inner rim 30 of the tire 20 (380).

The air pressure of the tire 20 corresponding to the difference value calculated by matching the calculated difference value with the air pressure data stored in advance in the memory unit 140 is detected (390).

Hereinafter, a control method of the tire inflation pressure measuring apparatus according to another embodiment of the present invention will be described with reference to FIG.

First, ultrasonic waves are transmitted to the tire 20 (410).

The ultrasonic waves reflected on the surface of the tire 20 and the inner rim 30 of the tire 20 are received (420).

The receiving time of ultrasonic waves reflected on the surface of the tire 20 and the inner rim 30 of the tire 20 is detected to detect the ultrasonic waves reflected on the surface of the tire 20 and the inner rim 30 of the tire 20 (430). ≪ / RTI >

At this time, the time can be counted from the time when the ultrasonic transmission unit 110 transmits the ultrasonic waves to the tire 20, and the time of reception of the ultrasonic waves reflected on the surface of the tire 20 and the inner rim 30 of the tire 20 May mean the time from when the ultrasonic wave is transmitted from the ultrasonic transmission unit 110 to when the ultrasonic wave is received by the ultrasonic reception unit 120. [

The air pressure of the tire 20 corresponding to the calculated difference value and the air pressure data stored in advance in the memory unit 140 is detected (440).

The detected air pressure of the tire 20 is compared with a predetermined reference air pressure to detect whether the detected air pressure of the tire 20 is lower than a predetermined reference air pressure (450).

At this time, if the detected air pressure of the tire 20 is lower than the predetermined reference air pressure, a warning signal is output (460) so that the driver of the automobile 10 or the repairer located outside the automobile 10 can recognize it.

Such a technique of measuring the tire air pressure using the ultrasonic sensor may be implemented in an application or may be implemented in the form of program instructions that can be executed through various computer components and recorded in a computer-readable recording medium. The computer-readable recording medium may include program commands, data files, data structures, and the like, alone or in combination.

The program instructions recorded on the computer-readable recording medium may be ones that are specially designed and configured for the present invention and are known and available to those skilled in the art of computer software.

Examples of computer-readable media include magnetic media such as hard disks, floppy disks and magnetic tape, optical recording media such as CD-ROMs and DVDs, magneto-optical media such as floptical disks, media, and hardware devices specifically configured to store and execute program instructions such as ROM, RAM, flash memory, and the like.

Examples of program instructions include machine language code such as those generated by a compiler, as well as high-level language code that can be executed by a computer using an interpreter or the like. The hardware device may be configured to operate as one or more software modules for performing the processing according to the present invention, and vice versa.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made therein without departing from the spirit and scope of the invention as defined in the appended claims. It will be possible.

10: Cars
20: Tire
30: rim
40: Fender
100: tire air pressure measuring device
110: Ultrasonic transmitter
120: Ultrasound receiver
130:
131: reception time calculating unit
132: reception time correction section
133: Air pressure detector
140:
150: Infrared sensor

Claims (17)

An ultrasonic transmitter mounted on the exterior of the tire and transmitting ultrasonic waves to the tire;
An ultrasonic wave receiving unit for receiving ultrasonic waves transmitted from the ultrasonic wave transmitting unit and reflected from the outside and inside of the tire; And
And a control unit for detecting an air pressure of the tire according to a reception time of ultrasonic waves reflected from outside and inside of the tire,
Wherein,
The method includes measuring a temperature of the tire, calculating a transmission speed of the ultrasonic wave that varies according to the temperature of the tire, and calculating a reception time that is reduced or increased according to the changed transmission speed of the ultrasonic wave by using the ultrasonic wave reflected from the tire inner rim And a reception time correction unit for correcting the reception time of the ultrasonic waves reflected on the inner rim of the tire by adding or subtracting the reception time. The method according to claim 1,
The ultrasound receiver may further include:
Wherein the ultrasonic wave transmitted from the ultrasonic wave transmitting unit receives ultrasonic waves reflected on the surface of the tire,
Wherein the ultrasonic wave transmitted from the ultrasonic transmission unit is transmitted through the surface of the tire and receives ultrasonic waves reflected on the inner rim of the tire. 3. The method of claim 2,
Receiving ultrasonic waves reflected by the inner rim of the tire,
Wherein an ultrasonic wave transmitted through the surface of the tire and having a transmission speed changed by the internal air pressure of the tire is reflected on the inner rim of the tire. The method according to claim 1,
Wherein,
Measuring a reception time of ultrasonic waves reflected from outside and inside of the tire,
And a reception time calculating section for calculating a time difference between the reception time of the ultrasonic wave reflected from the surface of the tire and the reception time of the ultrasonic wave reflected by the inner rim of the tire, Device. 5. The method of claim 4,
Wherein,
And an air pressure detecting section for comparing the calculated time difference with previously stored air pressure data and detecting an air pressure of the tire corresponding to the time difference. delete The method according to claim 1,
Wherein,
A corrected time difference between the reception time of the ultrasonic wave reflected by the corrected inner rim of the tire and the reception time of the ultrasonic wave reflected by the surface of the tire is calculated and the corrected time difference is compared with the previously stored air pressure data And detects the air pressure of the tire corresponding to the corrected time difference. The method according to claim 1,
To measure the temperature of the tire,
A tire inflation pressure measuring device, which is formed on a front fender and a rear fender of a vehicle, measures the temperature of the tire through an infrared sensor for measuring the surface temperature of the tire. The method according to claim 1,
Wherein the ultrasonic wave receiver and the ultrasonic wave transmitter are formed on a front fender and a rear fender of the vehicle. The method according to claim 1,
Further comprising an output section for outputting the detected air pressure information of the tire to an output device provided inside the vehicle or an output device outside the vehicle. An ultrasonic diagnostic apparatus comprising: an ultrasonic wave transmitting unit for transmitting ultrasonic waves to a tire of a vehicle and receiving the ultrasonic waves reflected from the surface of the tire and the inner rim of the tire,
The air pressure of the tire is detected according to the receiving time of the ultrasonic waves reflected on the surface of the tire and the inner rim of the tire,
Detecting the air pressure of the tire according to the receiving time of the ultrasonic waves reflected on the surface of the tire and the inner rim of the tire,
The surface temperature of the tire is measured to calculate the transmission speed of the ultrasonic wave which changes according to the surface temperature of the tire and the reception time of the ultrasonic wave reflected on the inner rim of the tire is corrected according to the calculated transmission speed And detecting the air pressure of the tire. 12. The method of claim 11,
Detecting the air pressure of the tire according to the receiving time of the ultrasonic waves reflected on the surface of the tire and the inner rim of the tire,
Calculating a time difference between the reception time of the ultrasonic waves reflected on the surface of the tire and the reception time of the ultrasonic waves reflected on the inner rim of the tire and comparing the calculated time difference with the previously stored air pressure data, And the air pressure corresponding to the calculated time difference is detected. delete 12. The method of claim 11,
And detecting the air pressure of the tire by correcting the reception time of ultrasonic waves reflected on the inner rim of the tire according to the transmission speed of the ultrasonic wave,
Further comprising a step of detecting the air pressure of the tire by adding or subtracting the reception time reduced or increased according to the calculated transmission speed to the reception time of ultrasonic waves reflected by the inner rim of the tire . 12. The method of claim 11,
And comparing the detected air pressure of the tire with a predetermined reference air pressure to detect whether the tire is normal or not. 16. The method of claim 15,
The detection of the normal state of the tire may be made,
And outputting a warning signal when the detected air pressure of the tire is less than the predetermined reference air pressure. A computer-readable recording medium having recorded thereon a computer program for executing a control method of a tire pressure measurement apparatus according to any one of claims 11, 12, 14,

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