KR20020073326A - Device for monitoring pressure of tire in vehicles - Google Patents

Abstract

The present invention relates to a tire pressure monitoring device for a vehicle that can be monitored by the driver by displaying the air pressure and temperature information of the tire in the lane.

A tire air pressure monitoring apparatus for a vehicle for this purpose includes a plurality of wireless transmitters for wirelessly transmitting air pressure data modulated by sensing the air pressure of the tire, and air pressure data of tires respectively transmitted from the plurality of wireless transmitters. And a wireless receiver for controlling to display and demodulate sequentially, and an indicator for displaying the plurality of tire air pressure data demodulated by the wireless receiver.

Description

Tire pressure monitoring device for automobiles {DEVICE FOR MONITORING PRESSURE OF TIRE IN VEHICLES}

The present invention relates to a tire pressure monitoring apparatus for a vehicle, and more particularly, to a tire pressure monitoring apparatus for a vehicle that can be monitored by a driver by displaying air pressure and temperature information of a tire inside a vehicle.

In general, a car tire is made of rubber, which is inserted around a wheel, and there are also rubber-only solid tires. However, a tire of a typical car is assembled with a wheel of a wheel to enclose a wheel, and a tube for blowing air inside. It is made of rubber on the outside.

The car tire is the only part where the road surface is in contact with the car. The car tire supports the load of the car, transmits the driving force, the braking force and the lateral force of the car, and has the functions of the spring and the damper to alleviate the impact on the road. When the tire of such a vehicle has a pressure higher than an appropriate pressure, the riding comfort becomes worse due to a trapping phenomenon, and the tire is quickly lost. When the pressure of the tire is low, the operability of the vehicle is lowered, and wear of the tire proceeds rapidly.

In addition, when the tire pressure of the car is lower than the appropriate pressure, fuel economy is also lowered, so maintaining the proper tire pressure is very important.

1 is a structural cross-sectional view of a general automobile tire.

A tube 4 fitted to the back of the tire 2 to maintain the air pressure is provided, and the outer side of the tube 40 maintains a constant volume in response to the air pressure and cushions the load according to the load or impact. (6) is provided. A bead that contacts the rim 10 of the wheel 8 to support the end of the carcass 6 against air pressure in the tire 2 and fixes the tire 2 to the rim 10 of the wheel 8. (12) is provided. The wire 14 is inserted in the bead 12 in the circumferential direction. And a tread 16 is provided in direct contact with the road surface to protect the inner carcass 6, and between the tread 16 and the carcass 6 absorbs external shocks and is formed on the tread 16. The breaker 18 which prevents a wound from hitting the carcass 6 is provided.

Car tires configured as described above are fixed to one side and the other side of the front and rear of the car to support the load of the car while making sufficient contact, transfer driving force and braking force to the road surface, absorb shock from the road surface, and adjust the direction of the car. Switch or maintain function.

These tires for automobiles are regulated by the type of tire or the size of the tire, so if the pressure is lower or higher than the normal pressure, the braking or turning of the tire will not be normally braked due to uneven wear or trapping, which may cause a safety accident. There is a danger. Therefore, the tires for automobiles should always maintain the prescribed pressure. It was not possible to check whether the air pressure of the tire was maintained at the prescribed pressure only when the tire was inflated with the prescribed pressure.

Accordingly, an object of the present invention is to provide a tire pressure monitoring apparatus capable of monitoring the air pressure of a tire by measuring the air pressure of the tire for a vehicle so that the driver can check the pressure.

Another object of the present invention is to provide a tire pressure monitoring device that enables the driver to monitor the tire air pressure to properly maintain the prescribed air pressure of the tire to improve ride comfort, improve fuel economy, and prevent accidents caused by tire damage. .

In order to achieve the above object, a tire air pressure monitoring apparatus of a vehicle of the present invention includes a plurality of radio transmitters for wirelessly transmitting air pressure data modulated by sensing the air pressure of the tire, and each of the plurality of radio transmitters. And a wireless receiver for controlling to sequentially receive and demodulate the transmitted air pressure data of the tire, and an indicator for displaying the plurality of tire air pressure data demodulated by the wireless receiver.

1 is a structural cross-sectional view of a typical automobile tire

2 is a block diagram of the entire system for monitoring the tire pressure according to an embodiment of the present invention

3 is a state diagram of a transmitter and a receiving antenna according to an embodiment of the present invention;

Figure 4a is a detailed structural diagram of the wireless transmitter is mounted on the wheel outside the tire according to an embodiment of the present invention

4b is a detailed structural diagram in which a wireless transmitter is mounted in a tire according to an embodiment of the present invention;

4c is a detailed structural diagram of mounting a wireless transmitter in a tire according to an embodiment of the present invention;

5 is a configuration diagram of one wireless transmitter according to an embodiment of the present invention.

6 is a structural diagram of a transmission data format applied to an embodiment of the present invention;

7 is a detailed circuit diagram of the carrier frequency generator 90 of FIG. 5 according to an embodiment of the present invention.

FIG. 8 is a detailed circuit diagram of the radio receiver 38 of FIG. 1 using an AM scheme according to an embodiment of the present invention.

9 is a detailed circuit diagram of the radio receiver 38 of FIG. 1 using an AM scheme according to another embodiment of the present invention.

FIG. 10 is a detailed circuit diagram of the radio receiver 38 of FIG. 1 using the FM system in one embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

20,22,24,26: Tires 30,32,34,36: Radio transmitter

38: radio receiver 40: indicator

50: air injection pipe 60: air pressure regulating valve

70: pressure sensor 72, 76: first and second amplification unit

74: temperature sensor 78: switch

80: analog-to-digital converter 82: microprocessor

84: switch drive unit 86: ID setting switch

88: position setting switch 90: carrier frequency generator

92: RF generator 94: battery

96: power supply voltage detector

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

2 is a block diagram of the entire system for monitoring the tire pressure according to an embodiment of the present invention.

Four radio transmitters (30, 32, 34, 36) installed on the wheels mounted on the four tires (20, 22, 24, and 26) to wirelessly transmit the modulated air pressure data by detecting the tire air pressure. ) And a radio receiver 38 for controlling to sequentially receive and demodulate and display the air pressure data of the tires transmitted from the four radio transmitters 30, 32, 34, and 36, respectively, by the receiver 38. And an indicator 40 for displaying the demodulated four tire air pressure data. The indicator 40 is installed in the driver's seat of the vehicle so that the driver can check the air pressure and tire temperature and the level of the battery.

3 is a diagram illustrating a transmitter and a reception antenna mounted according to an exemplary embodiment of the present invention.

The four tires 20, 22, 24, and 26 are each equipped with tire wheels 28, and the wireless wheels 30, 32, 34, and 36 are provided on the tire wheels 28, respectively. And it is composed of the antenna (ANT1, ANT2, ANT3, ANT4) installed in the vehicle body to receive the wireless data transmitted from the four radio transmitters (30, 32, 34, 36).

4A is a detailed structural diagram in which a wireless transmitter is mounted on a wheel outside a tire according to an embodiment of the present invention;

4b is a detailed structural diagram in which a wireless transmitter is mounted in a tire according to an exemplary embodiment of the present invention.

4c is a detailed structural diagram in which a wireless transmitter is mounted in a tire according to an exemplary embodiment of the present invention.

The tire 20 is mounted on the tire wheel 42, and an air injection pipe 50 is connected to the tire 20 through the tire wheel 42, and at the inlet of the air injection pipe 50. An air pressure control valve 60 is installed, and a wireless transmitter 30 is installed at the end of the air injection pipe 50 inside the tire wheel 42.

Since the temperature inside the tire rises to 180 ° C. or higher when driving a car at high speed, the use of a sensor and a circuit using a semiconductor is impossible, and thus the wireless transmitter 30 is mounted on the wheel 42 outside the tire as shown in FIG. 4A. Since the temperature inside the tire rises to 180 ° C. or higher when the vehicle is driven at high speed, the wireless transmitter 30 may be mounted inside the tire as shown in FIG. 4B when using a semiconductor that can be used at 180 ° C. FIG.

In addition, since the tire wheel 42 generally uses aluminum having good thermal conductivity, a portion of the tire wheel 42 contacting the wireless transmitter 30 and the tire wheel 42 may be made of metal so that the temperature outside the tire can be effectively transmitted. The part in contact with the air in the tire is packaged with a poor thermal conductivity plastic 43 material so that the wireless transmitter 30 minimizes the influence of temperature.

In addition, although the tire wheel 42 and the wireless transmitter 30 are configured separately in the above configuration, the tire wheel 42 having a mounting portion to which the wireless transmitter 30 can be integrally mounted to the tire wheel 42 is developed.

In the above configuration, only the radio transmitter 30 is exemplified, but the other radio transmitters 32, 34, and 36 have the same structure.

5 is a configuration diagram of one radio transmitter according to an embodiment of the present invention.

Pressure sensor 70 for detecting the air pressure of the tire, a temperature sensor 74 for detecting the temperature in the tire, operational amplifiers (OP1 ~ OP3) and resistors (R1 ~ R7) is composed of the pressure sensor ( The first amplifier 72 for amplifying the tire air pressure signal detected from the 70 to a predetermined level, the operational amplifier (OP4) and the resistor (R7) consists of a temperature sensing sensed by the temperature sensor 74 A second amplifier 76 for amplifying the signal to a predetermined level, a battery 94 for supplying power to the wireless transmitter, a power supply voltage detector 96 for sensing a power supply voltage level of the battery 94, ID amplification switch 86 for setting a unique ID for distinguishing a vehicle, a positioning switch 88 for setting a position of a tire, and amplified from the first and second amplifiers 72 and 76. Receives the power voltage detection level from the pressure detection signal, the temperature detection signal and the power supply voltage detector 96 A switch 78 for selecting and outputting one signal by a positive switching selection signal, and an analog / digital converter (A / D) 80 for converting and outputting the signal selected and output from the switch 78 into a digital signal; And receiving and setting a unique ID and tire positioning data for distinguishing a vehicle from the ID setting switch 86 and the positioning switch 88, and receiving a digitally converted signal from the analog / digital converter 80. A microprocessor 82 for converting and outputting a unique ID for distinguishing a predetermined vehicle and tire positioning data into a predetermined data format, a frequency generator 90 generating a predetermined carrier frequency, and generating the frequency Receives a carrier frequency generated from the unit 90 and modulates the formatted data received from the microprocessor 82 to wirelessly antenna It is composed of an RF generator 92 that transmits through (ANT).

In FIG. 5, only one radio transmitter is illustrated, and four radio transmitters 30, 32, 34, and 36 each have the same configuration as that of FIG. 5.

6 is a structural diagram of a transmission data format applied to an embodiment of the present invention.

It consists of a synchronization signal SYNC, an ID signal for distinguishing an automobile, a tire position signal, a tire air pressure signal, a tire temperature signal, a power supply voltage signal, and an error check signal CRC.

7 is a detailed circuit diagram of the carrier frequency generator 90 of FIG. 5 according to an embodiment of the present invention.

A first oscillation frequency (Surface Acoustic Wave) having an oscillation function and a first oscillation frequency corresponding to oscillation of the SAW element (100) and including a change (e) caused by the effects of ambient vibration and temperature ( The first oscillation circuit 102 generating f1 + e), the SAW element 104 having the oscillation function, and the oscillation of the SAW 104 correspond to the oscillation of the SAW 104, a second oscillation circuit 106 for generating a second oscillation frequency f2 + e including e), and first and second generated from the first oscillation circuit 102 and the second oscillation circuit 106; By mixing the oscillation frequencies f1 + e and f2 + e, the difference frequency f1-f2 does not include the change due to temperature and vibration and the difference frequency f1 including the change due to temperature and vibration + f2 + e), a mixer 108 that outputs two differential frequencies, and a differential frequency including a change e caused by temperature and vibration by receiving two differential frequencies output from the mixer 108; f1 + f2 + e) A band pass filter 110 for outputting only the difference frequencies f1 to f2 not including the change, and a difference frequency including the change e due to temperature and vibration from the band pass filter 110. And a frequency multiplication circuit 112 that inputs the removed frequency and multiplies by a predetermined multiple to output the multiplied frequency.

8 is a detailed circuit diagram of the radio receiver 38 of FIG. 1 using the AM method according to an embodiment of the present invention.

Four antennas ANT1 to ANT4 for receiving data wirelessly transmitted from a transmitter and wireless data received from the four antennas ANT1 to ANT4 are respectively inputted, and one is selected and output by a predetermined switching selection signal. A switch 120, an RF amplifier 124 for amplifying the wireless data selected and output from the switch 120 to a predetermined level, and wireless data amplified and output from the RF amplifier 124. The detection circuit 126, an ID setting switch 130 for setting a unique ID for distinguishing a car, and a unique ID for distinguishing a car from the ID setting switch 130 are received and set, and the detection circuit Receives the detected signal from (126) and generates an alarm control signal when it exceeds the prescribed air pressure and temperature data compared with the prescribed pressure and temperature data, and detects the detected air pressure and temperature. The microprocessor 128 controls to display data, the buzzer 132 which generates a buzzer sound by the alarm control signal of the microprocessor 82, and the air pressure and the air pressure by the control signal of the microprocessor 82. It consists of the LCD 40 which displays temperature data.

1 to 8 will be described in detail the operation of the preferred embodiment of the present invention.

The four tire wheels 42, 44, 46, and 48 on which the four tires 20, 22, 24, and 26 are mounted are respectively provided with one radio transmitter 30, 32, 34, 36. The wireless transmitters 30, 32, 34, 36 mounted on the four tire wheels 42, 44, 46, and 48, respectively, have the configuration as shown in FIG. 5, and the four wireless transmitters 30, 32, 34, 36. Since all of the same operations are performed, the operation of the wireless transmitter 30 installed in the tire wheel 42 on which the tire 20 is mounted will be described by way of example.

A wireless transmitter including a pressure sensor 70 and a temperature sensor 74 is installed on the air pressure control valve 60 as shown in FIG. 4A. The pressure sensor 70 detects the pressure of the tire 20 and outputs the detected signal. The first amplifier 72 is composed of operational amplifiers OP1 to OP3 and resistors R1 to R7 to amplify and output the tire air pressure signal detected by the pressure sensor 70 to a predetermined level. The temperature sensor 74 senses the temperature in the tire. The second amplifier 76 includes an operational amplifier OP4 and a resistor R7 to amplify and output the temperature sensing signal detected by the temperature sensor 74 to a predetermined level. The battery 94 supplies power to each part of the radio transmitter. The power supply voltage detector 96 detects and outputs a power supply voltage level of the battery 94.

The ID setting switch 86 is a switch for inputting and setting a unique ID for distinguishing a car by a user's operation. The positioning switch 88 is a switch for setting the position of the transmitter by a user's operation. The microprocessor 82 receives and sets a unique ID for identifying a vehicle and positioning data of a tire from the ID setting switch 86 and the positioning switch 88, and sequentially sets the first to the first in a predetermined time unit. 3 Generate and output a switching drive signal. Then, the switch driver 84 receives the first to third switching driving signals from the microprocessor 82 and generates a switching selection signal at predetermined time intervals to drive the switch 78. The signals output from the amplifier 72, the second amplifier 76, and the power supply voltage detector 96 are switched and output once per predetermined time unit. At this time, the analog / digital converter (A / D) 80 converts the signal selected by the switch 78 into a digital signal and applies it to the microprocessor 82. Therefore, the microprocessor 82 receives the digitally converted signal from the analog-to-digital converter 80 and converts the unique ID for distinguishing the preset vehicle and the tire positioning data into a predetermined data format as shown in FIG. 6. Output Here, the ID setting switch ID is set by the ID setting switch 86 so that when there are a plurality of cars, if there is no ID, the ID is not confused, and even if it is sent to another car, the ID is not operated. .

The carrier frequency generator 90 generates a predetermined carrier frequency and applies it to the RF generator 92. The RF generator 92 receives the carrier frequency generated from the frequency generator 90 and modulates the data formatted as shown in FIG. 6 received from the microprocessor 82 and transmits it wirelessly through the antenna ANT. .

An operation of the carrier frequency generator 92 will be described in detail with reference to FIG. 7.

When a car runs at high speed, an environment of high temperature and high vibration atmosphere is formed inside and outside the tire. Therefore, the crystal oscillator is generally used as a carrier frequency generator of the RF generator 92. In the present invention, since the crystal oscillator cannot be used due to the impact due to high vibration, the SAW elements 100 and 104 are used. The surface acoustic wave (SAW) devices 100 and 104 have oscillation functions with a very small change in natural frequency. The first oscillation circuit 102 generates and outputs a first oscillation frequency f1 corresponding to the oscillation of the SAW element 100. The second oscillation circuit 106 generates and outputs a second oscillation frequency f2 corresponding to the oscillation of the SAW 104. The output of the first oscillator circuit 100 becomes f1 + e and the output of the second oscillator circuit 106 becomes f2 + e. Here, e represents the change in the output frequency of the SAW caused by the temperature change and vibration of the surroundings, and since the two SAW elements 100 and 104 are in the same environment, the magnitude of the change in the output frequency is always the same. The mixer 108 mixes the first and second oscillation frequencies f1 and f2 generated from the first oscillation circuit 102 and the second oscillation circuit 106 so that the change e due to temperature and vibration is changed. Outputs two included frequencies. That is, the mixer 108 outputs two difference frequencies, f1 + f2 + 2e and f1-f2. The band pass filter 110 receives f1 + f2 + 2e signals and f1-f2, which are two difference frequencies output from the mixer 108, and f1, which is a difference frequency including variation e caused by temperature and vibration. + f2 + 2e removes the signal and outputs it. That is, the band pass filter 110 may obtain Δf, which is a difference signal from which the change e due to temperature and vibration is removed. The frequency multiplier circuit 112 inputs a frequency Δf from which the difference frequency including the change e due to temperature and vibration is removed from the band pass filter 110 to a predetermined multiple A. The multiplication is performed and the multiplied frequency 2AΔf is applied to the RF generator 92.

On the other hand, the radio signals (RF signals) transmitted from the four radio transmitters 30, 32, 34, and 36 that perform the above operation are received through the four antennas ANT1 to ANT4 in the radio receiver 28, and the vehicle interior. It is displayed on the indicator 40 installed in the, when the operation of the radio receiver 28 will be described with reference to Figure 8, the antenna (ANT1 ~ ANT4) is close to the four radio transmitters (30, 32, 34, 36), respectively. By placing it, the output of the radio transmitters 30, 32, 34, 36 is lowered below the weak output level to minimize the influence on the antennas other than the adjacent receiving antennas. In addition, the lower the output has the advantage of extending the life of the battery.

The four antennas ANT1 to ANT4 receive data wirelessly transmitted from four radio transmitters 30, 32, 34, and 36, respectively. The ID setting switch 130 is a switch for setting a unique ID for distinguishing a vehicle. The unique ID for identifying the car sets the transmitter and receiver to match. The microprocessor 128 receives and sets a unique ID for distinguishing a vehicle input from the ID setting switch 130. The microprocessor 128 generates and outputs the eleventh to fourteenth switching driving signals sequentially in predetermined time units. Then, the switch driver 122 receives the eleventh through fourteenth switching driving signals from the microprocessor 128 and generates the eleventh through fourteenth switching selection signals at predetermined time intervals to drive the switch 120. The switch 120 switches the signals received from the first to fourth antennas ANT1 to ANT4 once in a predetermined time unit and outputs them to the RF amplifier 124. The RF amplifier 124 amplifies the wireless data selectively output from the switch 120 to a predetermined level and outputs the wireless data to the detection circuit 126. The detection circuit 126 receives the wireless data amplified and output from the RF amplifier 124 and detects and outputs the wireless data to the microprocessor 128. The microprocessor 128 receives the detected signal from the detection circuit 126 and compares the ID signal with a preset signal and receives data only when the ID signal matches. When the ID signal matches, the microprocessor 128 receives a pressure signal, a temperature signal, and a power supply voltage. The signal is compared with the prescribed pressure and temperature data and the power voltage signal, respectively, and when the prescribed air pressure and temperature data and the power voltage do not match the prescribed values, an alarm control signal is generated and the buzzer sounds by the buzzer 132. The temperature data is also used to compensate for the temperature characteristics of the pressure sensor. The detected air pressure, temperature data, and power supply voltage level are controlled to be displayed on the LCD 40. However, the microprocessor 128 pre-stores prescribed air pressure and temperature data and power supply voltage, and when the air pressure and temperature data and power supply voltage detected from the detection circuit 126 are of a prescribed value, a buzzer sounds. Instead, the detected air pressure and temperature data and the power supply voltage value may be displayed on the LCD 40.

9 is a detailed circuit diagram of the radio receiver 38 of FIG. 1 using an AM scheme according to another embodiment of the present invention.

Four antennas ANT1 to ANT4 for receiving data wirelessly transmitted from four transmitters, and four RF amplifiers for amplifying wireless data received from the four antennas ANT1 to ANT4 to a predetermined level, respectively. Four detection circuits 148, 150, 152, and 154 for receiving, detecting, and outputting the wireless data amplified and output from the four RF amplifiers 140, 142, 144, and 146, respectively. ), A switch 156 for receiving detection data output from the four detection circuits 148, 150, 152, and 154, respectively, and outputting one by a predetermined switching selection signal, and a unique for distinguishing an automobile. An ID setting switch 158 for setting an ID and a vehicle identification ID are input from the ID setting switch 158, and a signal selected and output from the switch 156 is received and compared with a prescribed pressure and temperature data. Air pressure and temperature And a buzzer that generates an alarm control signal upon exceeding the detector and generates a buzz sound by the microprocessor 160 controlling the display of the detected air pressure and temperature data, and the alarm control signal of the microprocessor 160. 164, and the LCD 40 for displaying the air pressure and temperature data and the power supply voltage level by the control signal of the microprocessor 160. This method has an advantage in that the amplifier and the detection circuit are close to the antenna, so that the distortion of the signal due to noise can be prevented compared with the method of FIG.

Referring to FIG. 9, the operation of the wireless receiver 38 according to another embodiment having the AM method of the present invention will be described.

The four antennas ANT1 to ANT4 receive data wirelessly transmitted from four radio transmitters 30, 32, 34, and 36, respectively. The ID setting switch 162 is a switch for setting a unique ID for distinguishing a vehicle. The unique ID for identifying the vehicle is set to match the radio transmitter and the radio receiver. The microprocessor 160 receives and sets a unique ID for distinguishing a vehicle input from the ID setting switch 162. The microprocessor 160 generates and outputs the eleventh to fourteenth switching driving signals sequentially in predetermined time units. Then, the switch driver 158 receives the eleventh through fourteenth switching driving signals from the microprocessor 160 and generates the eleventh through fourteenth switching selection signals at predetermined time intervals to drive the switch 156.

At this time, four RF amplifiers 140, 142, 144, and 146 amplify radio data received from the four antennas ANT1 to ANT4 to predetermined levels, respectively, to four detection circuits 148, 150, 152, and 156. Output The four detection circuits 148, 150, 152, and 156 receive wireless data amplified and output from the four RF amplifiers 140, 142, 144, and 146, and detect and output the wireless data to the switch 156. The switch 156 selects and switches the signals received from the four detection circuits 148, 150, 152, and 156 one by one in a predetermined time unit and outputs them to the microprocessor 160. The microprocessor 160 receives the detected signals from the four detection circuits 148, 150, 152, and 156 and receives data only when the ID signals match with the preset signals, and receive data. The tire pressure signal, temperature signal, and power voltage signal are compared with the prescribed pressure and temperature data and the power voltage signal, respectively, and an alarm control signal is generated when the air pressure and temperature data and the specified power voltage value do not match. A buzzer sound is generated by 164, and the temperature data is also used to compensate for the temperature characteristic of the pressure sensor. The detected air pressure and temperature data are controlled to be displayed on the LCD 40. However, the microprocessor 160 pre-stores prescribed air pressure and temperature data and power supply voltage, and the air pressure and temperature data and power supply voltage detected from the four detection circuits 148, 150, 152 and 154, respectively. In the case of the prescribed value, the buzzer does not occur and the air pressure and temperature data and the power supply voltage value detected on the LCD 40 may be displayed.

FIG. 10 is a detailed circuit diagram of the radio receiver 38 of FIG. 1 using the FM system according to an embodiment of the present invention.

Four antennas ANT1 to ANT4 for receiving data transmitted wirelessly from a transmitter, and an FM demodulation unit 190 for receiving FM data demodulated and outputting the wireless data received from the four antennas ANT1 to ANT4; , An ID setting switch 182 for setting a unique ID for distinguishing a car, and a unique ID for distinguishing a car set from the ID setting switch 182 are received and set, and the FM demodulation unit 190 is set. Receives demodulated signal and generates alarm control signal when it exceeds the prescribed air pressure and temperature data, compensates the temperature characteristic of pressure sensor by using temperature data, and demodulates the air. A microprocessor 180 which controls to display pressure and temperature data, a buzzer 184 which generates a buzzer sound by an alarm control signal of the microprocessor 180, and the micro By a control signal processor 180 is composed of LCD (40) that displays the air pressure and temperature data.

The FM demodulation unit 190 receives a radio data received from four antennas ANT1 to ANT4, respectively, and a switch 191 for outputting one by a predetermined switching selection signal from the switch 191. The RF amplifier 170 receives the selected output radio data and amplifies and outputs the radio data to a predetermined level, the local oscillator 172 generating a predetermined local oscillation frequency, and the radio data amplified and output from the RF amplifier 170. A mixer 174 that mixes with the local oscillation frequency generated from the local oscillator 172 and converts the intermediate frequency signal into an intermediate frequency signal; and an intermediate frequency amplifier that amplifies the intermediate frequency signal converted and output from the mixer 174 to a predetermined level. 176, and an FM detection circuit 178 that receives the intermediate frequency signal amplified by the intermediate frequency amplifier 176, detects and outputs the intermediate frequency signal.

The RF amplifier 170 receives wireless data received from the antenna ANT1, amplifies the RF data to a predetermined level, and applies it to the mixer 174. The local oscillator 172 generates a predetermined local oscillation frequency and applies it to the mixer 174. The mixer 174 receives the wireless data amplified and output from the RF amplifier 170, mixes the local oscillation frequency generated from the local oscillator 172, converts it into an intermediate frequency signal, and outputs the intermediate frequency signal to the intermediate frequency amplifier. The intermediate frequency amplifier 176 amplifies the intermediate frequency signal converted from the mixer 174 to a predetermined level and outputs the intermediate frequency signal to the FM detection circuit 178. The FM detection circuit 178 receives the intermediate frequency signal amplified from the intermediate frequency amplifier 176 and detects the applied intermediate frequency signal to the microprocessor 180.

The microprocessor 180 receives the detected signal from the FM demodulation unit 190 and compares the ID signal with a preset signal and receives data only when the ID signal is matched. After reading, it analyzes tire pressure signal, temperature signal and power voltage signal and compares the specified pressure and temperature data with power voltage signal respectively, and alarms when it does not match the specified air pressure and temperature data and specified power voltage value. Generate a control signal to generate a buzzer sound by the buzzer 184, compensate the temperature characteristics of the pressure sensor using the temperature data, and the detected air pressure and temperature data and the power supply voltage level to the LCD 40 Control to display. However, the air pressure and temperature data and the power supply voltage are stored in advance in the microprocessor 180, and when the air pressure and temperature data and the power supply voltage respectively detected from the FM detection circuit 178 are prescribed values, a buzzer sounds. Does not occur and may display the detected air pressure and temperature data and the power supply voltage value on the LCD 40.

In FIG. 10, when the FM receiver uses the wireless receiver 38 of FIG. 1 according to an embodiment of the present invention, four wireless transmitters (ANT1 to ANT4) and one FM demodulator 190 are used. 30, 32, 34, 36) to receive the tire position signal, the air pressure, temperature, power voltage level detection signal, but by increasing the output of the radio transmitter, using one antenna and one FM demodulator A wireless receiver may be implemented to receive and display a detection signal of air pressure, temperature, and power voltage level transmitted from the wireless transmitters 30, 32, 34, and 36 and generate an alarm.

In an embodiment of the present invention, the air pressure and tire temperature of the tire and the power supply voltage level of the battery for supplying the power voltage to the transmitter of the monitoring device are provided to the wireless transmitter, but only the tire air pressure is detected and transmitted. In addition, it is possible to perform wireless transmission by sensing only the tire temperature or by sensing only the power supply voltage level of the battery without departing from the scope of the present invention.

If only the air pressure of the tire is detected and transmitted, the data format of FIG. 6 includes a synchronization signal, an ID signal for distinguishing a vehicle, a tire position signal, a tire air pressure signal, a CRC signal, and the like. When sensing and transmitting, the data format of FIG. 6 may include a synchronization signal, an ID signal for distinguishing a vehicle, a tire position signal, a tire temperature signal, a CRC signal, and the like.

As described above, the present invention allows the driver to monitor the air pressure and tire temperature of the tire of the vehicle from the driver's seat to prevent safety accidents caused by the tire pressure being higher or lower than the prescribed value, and to prevent the tire pressure from the prescribed value. By maintaining it, there is an advantage that can improve the riding comfort and fuel economy.

In addition, it measures the power supply voltage level of the battery supplied to the monitoring device to detect the air pressure and temperature of the tire so that the driver can check it, and if it falls below the set voltage, an alarm is generated to prevent the malfunction of the tire pressure monitoring device. There is an advantage to that.

In addition, by using the differential frequency using two SAW elements to stabilize the carrier frequency to determine the reliability of the radio transmitter mounted on the tire of high vibration and high temperature atmosphere, the tire pressure monitoring is secured even in the environment with high vibration and temperature change. This has a possible advantage.

Claims (21)

In the tire air pressure monitoring device of an automobile, A plurality of wireless transmitters for wirelessly transmitting the modulated air pressure data by sensing the air pressure of the tire; A wireless receiver which controls to sequentially receive and demodulate and display air pressure data of tires respectively transmitted from the plurality of wireless transmitters; And an indicator for displaying the plurality of tire air pressure data demodulated by the wireless receiver. The method of claim 1, The indicator is a tire air pressure monitoring device of the vehicle, characterized in that installed in the driver's seat of the vehicle interior so that the driver can check the air pressure and tire temperature and the level of the battery. The method of claim 2, The wireless transmitter of the tire air pressure monitoring device, characterized in that mounted to each of the wheel of the plurality of tires. The method of claim 3, wherein the plurality of wireless transmitters, Pressure sensor for detecting the air pressure of the tire, An analog / digital converter for converting and outputting a tire air pressure sensing signal digital signal detected by the pressure sensor; A first controller for receiving a digitally converted signal from the analog / digital converter and converting a unique ID and tire positioning data into a predetermined data format for distinguishing a predetermined vehicle; And an RF generating unit for modulating the formatted data received from the first control unit and wirelessly transmitting the modulated data through the antenna. The method of claim 4, wherein the plurality of wireless receivers, A plurality of antennas for receiving data transmitted wirelessly from the transmitter; A switch which receives wireless data received from the plurality of antennas and selects and outputs one by a predetermined switching selection signal; A detection circuit for receiving the detected and outputted wireless data from the switch and outputting the detected data; Receives the detected signal from the detection circuit and compares it with the prescribed pressure and temperature data to generate an alarm control signal when the specified air pressure and temperature data are exceeded, and compensates the temperature characteristics of the pressure sensor using the temperature data. And a second control unit for controlling to display the detected air pressure and temperature data. The method of claim 4, wherein A temperature sensor for detecting the temperature of the tire, And a switch configured to receive a pressure sensing signal and a temperature sensing signal detected from the pressure sensor and the temperature sensing sensor and select one signal by a switching selection signal of the second control unit and output the signal to the analog / converter. Tire air pressure monitoring device. The method of claim 6, A battery for supplying power to the wireless transmitter, Detecting a power supply voltage level of the battery and using the switch, a power supply voltage detection unit; An ID setting switch for applying a setting signal to the first control unit to set a unique ID for distinguishing a vehicle; A tire air pressure monitoring apparatus for a vehicle, further comprising a positioning switch for applying a signal for setting a tire position to the controller. The method of claim 6, The data format includes a synchronous signal (SYNC), an ID signal for distinguishing a vehicle, a tire position signal, a tire air pressure signal, a tire temperature signal, a power voltage signal, and an error check signal (CRC). Air pressure monitoring device. The method of claim 4, wherein the wireless receiver, A plurality of antennas for receiving data transmitted wirelessly from the plurality of radio transmitters, respectively; A plurality of RF amplifiers each amplifying radio data received from the plurality of antennas to a predetermined level; A plurality of detection circuits for receiving, detecting and outputting wireless data amplified and output from the plurality of RF amplifiers, respectively; A switch which receives detection data output from the plurality of detection circuits, respectively, and selects and outputs one by a predetermined switching selection signal; Receives the signal selected and output from the switch and compares it with the prescribed pressure and temperature data to generate an alarm control signal when the specified air pressure and temperature data are exceeded, and compensates the temperature characteristics of the pressure sensor using the temperature data. And a second control unit configured to control the display of the detected air pressure and temperature data. The method of claim 8, And an ID setting switch connected to the second control unit for setting a unique ID for distinguishing a vehicle. The method of claim 1, Pressure sensor for detecting the air pressure of the tire, A temperature sensor for sensing the temperature of the tire, a first amplifier for amplifying the tire air pressure signal detected by the pressure sensor to a predetermined level; A second amplifier for amplifying the temperature detection signal detected by the temperature sensor to a predetermined level; A battery supplying power, A power supply voltage detector for detecting a power supply voltage level of the battery; ID setting switch for setting a unique ID to distinguish the car, Positioning switch for setting the position of the tire, A switch for receiving and outputting a pressure sensing signal and a temperature sensing signal amplified by the first and second amplifying units and a power supply voltage sensing level from a power supply voltage sensing unit, and outputting one signal by a predetermined switching selection signal; An analog / digital converter for converting the signal output from the switch to a digital signal and outputting the digital signal; A unique ID for distinguishing a car from the ID setting switch and the positioning switch and a tire position setting data are input and set, and a unique ID for distinguishing a preset car by receiving a digitally converted signal from the analog / digital converter. A first control unit which converts the positioning data of the watt tire into a predetermined data format and outputs the converted tire data; A frequency generator for generating a predetermined carrier frequency, Receiving a carrier frequency generated from the frequency generating unit for the tire air pressure monitoring device for a vehicle characterized in that it comprises a RF generator for modulating the formatted data received from the first control unit and transmits through the antenna wirelessly. The method of claim 10, wherein the wireless receiver, A plurality of antennas for receiving data transmitted wirelessly from the plurality of transmitters; A second switch which receives wireless data received from the plurality of antennas, respectively, and selects and outputs one by a predetermined switching selection signal; An RF amplifier for amplifying the wireless data selectively output from the second switch to a predetermined level; A detection circuit for receiving and detecting and outputting wireless data amplified and output from the RF amplifier; ID setting switch for setting a unique ID to distinguish the car, A unique ID for distinguishing a vehicle from the ID setting switch is input and set, and when a signal detected from the detection circuit is received and compared with a prescribed pressure and temperature data, an alarm control signal is exceeded. And a second controller configured to compensate for the temperature characteristic of the pressure sensor using temperature data and to control the display of the detected air pressure and temperature data. The method according to claim 10 or 11, wherein The tire air pressure monitoring apparatus of the vehicle further comprising a buzzer for generating a buzzer sound by the alarm control signal of the second control unit. The method of claim 10 or 11, wherein the carrier frequency generator, A first SAW element having an oscillation function, A first oscillation circuit for generating a first oscillation frequency f1 + e including a variation e caused by ambient vibration and temperature in response to oscillation of the first SAW element; A second SAW element having an oscillation function, A second oscillation circuit for generating a second oscillation frequency f2 + e including a variation e caused by ambient vibration and temperature in response to oscillation of the second SAW element; The first and second oscillation frequencies f1 + e and f2 + e generated from the first oscillation circuit and the second oscillation circuit are mixed so that the difference frequency f1 does not include the change e caused by vibration and temperature. -f2) and a mixer for outputting the difference frequency (f1 + f2 + e) including the vibration and the change of temperature (e), A band pass filter which receives two difference frequencies output from the mixer and removes and outputs a difference frequency including a change due to temperature and vibration; Tire pressure monitoring of a vehicle, comprising: a frequency multiplication circuit configured to multiply and output a frequency in which a difference frequency including a change due to temperature and vibration is removed from the band pass filter and multiply by a predetermined multiple Device. The method of claim 10, wherein the wireless receiver, A plurality of antennas for respectively receiving data transmitted wirelessly from the plurality of transmitters, A plurality of RF amplifiers each amplifying radio data received from the plurality of antennas to a predetermined level; A plurality of detection circuits for respectively receiving and detecting wireless data amplified and output from the plurality of RF amplifiers; A second switch which receives detection data output from the plurality of detection circuits and selects and outputs one by a predetermined switching selection signal; ID setting switch for setting a unique ID to distinguish the car, Receives and sets a vehicle identification ID from the ID setting switch, receives a signal selected and output from the switch and generates an alarm control signal when the prescribed air pressure and temperature data are exceeded, and exceeds the prescribed pressure and temperature data. A second controller for compensating the temperature characteristic of the pressure sensor using temperature data and controlling to display the detected air pressure and temperature data; Tire air pressure monitoring apparatus for a vehicle, characterized in that the buzzer for generating a buzzer sound by the alarm control signal of the second control unit. The method of claim 10, wherein the wireless receiver, A plurality of antennas for receiving data transmitted by including a position signal of a tire from a plurality of radio transmitters; An FM demodulator for receiving FM data received from the plurality of antennas, respectively, and demodulating and outputting the FM data; ID setting switch for setting a unique ID to distinguish the car, Receives and sets a unique ID for distinguishing a set vehicle from the ID setting switch, receives a demodulated signal from the FM demodulator, determines a tire position, and compares a prescribed air pressure and temperature data with a prescribed pressure and temperature data. A second controller for generating an alarm control signal when the data is exceeded, compensating for the temperature characteristic of the pressure sensor using temperature data, and displaying the demodulated air pressure and temperature data; And a buzzer for generating a buzzer sound by the alarm control signal of the second controller. The method of claim 10, The reception antenna is a tire air pressure monitoring device for a vehicle, characterized in that as close to the wireless transmitter as possible to receive the wireless transmission signal of the weak output level transmitted from the wireless transmitter to extend the life of the battery. The method of claim 16, The wireless transmitter is a tire air pressure monitoring device for a vehicle, characterized in that mounted on the outside of the tire to reduce the effect of the internal temperature of the tire rising to high temperatures during high-speed driving. The method of claim 16, The wireless transmitter is connected to aluminum to increase the thermal conductivity with the outside of the tire when mounted on the inside of the tire, and the tire air pressure monitoring of the vehicle, characterized in that the packaging in plastic, so that the high heat inside the tire is not transmitted well Device. The method of claim 16, The wireless transmitter is a tire air pressure monitoring device of the vehicle, characterized in that mounted integrally with the tire wheel on a portion of the inside or outside of the tire wheel. The method of claim 15, wherein the FM demodulation unit, A switch for receiving wireless data received from a plurality of antennas and selectively outputting one by a predetermined switching selection signal, an RF amplifier for receiving and outputting wireless data selectively output from the switch to a predetermined level, A local oscillator generating a local oscillation frequency, a mixer which receives wireless data amplified and output from the RF amplifier, mixes with the local oscillation frequency generated from the local oscillator, converts the intermediate oscillation signal into an intermediate frequency signal, and converts the output from the mixer And an intermediate frequency amplifier for amplifying the intermediate frequency signal to a predetermined level, and an FM detector circuit for receiving and detecting the intermediate frequency signal amplified from the intermediate frequency amplifier.