JP2000103209A - Tire inflation pressure supervisory system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To execute the ID registration by the simple operation at a receiver side by storing ID received during an ON-period of a registering switch of a receiver in EEPROM inside of the receiver as ID of a transmitter to be recognized in the receiver. SOLUTION: An ID registering mode for writing ID received by a receiver 4 to EEPROM 13 is obtained by turning on a registering switch 12 of the receiver 4. On the other hand, at a transmitter side, the pressure data is transmitted as the pressure abnormality when the change of pressure by more than specific pressure generates as the result of the measurement of the pressure. In the ID registering, the pressure is changed by letting air out of a tire by pressing a shaft part of an air valve of the tire to be registered. The transmitter detects the change of pressure and transmits the data. When the reception of data for four wheels has been completed, the receiver 4 writes the received ID number to EEPROM 13. Whereby the ID registering operation can be executed by the simple setting operation of the receiver 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to ID registration of a transmitter in a tire pressure monitoring system.

[0002]

2. Description of the Related Art A pressure switch for detecting tire pressure and an electromagnetic resonance circuit which is changed by the pressure switch are provided on the tire side, and the resonance state of the resonance circuit is wirelessly detected from a device provided on the vehicle body. A tire pressure detecting device and the like have been proposed so far. As a result of monitoring the tire pressure, the state of the pressure switch is determined by registering a predetermined individual ID number in a receiver installed in the vehicle, so that necessary tire pressure information is used as a determination material. I have.

[0003] For this reason, the ID registration work is very important. As a method for registering the ID, a receivable ID number is registered in the receiver in advance, or a magnet proposed in JP-A-8-505939 is transmitted. Forcible transmission was performed by a method of approaching the vicinity of the device, and ID registration was performed on the receiver side. In Japanese Patent Application Laid-Open No. 9-210827, the transmitter ID of the tire pressure warning device is learned and automatically registered.
A method for updating D has been proposed.

[0004] These prior arts are all excellent ideas that can monitor the tire pressure during running by a radio signal, detect a decrease in the tire pressure early, and send an alarm to the driver's seat. However, the problem is that when performing consistent manufacturing assembly and inspection on a vehicle production line, if the vehicle is equipped with a tire pressure alarm device, the inspection process becomes complicated. That is, if the receivable ID on the receiver side is determined in advance, a transmitter mounting step must be prepared in accordance with the receiver, and the cost increases due to an increase in the number of work steps.

[0005] In addition, forced transmission from the transmitter is enabled by a method in which the magnet is brought close to the vicinity of the transmitter, and the receiver side receives the I
The method of enabling re-registration of D requires that an element circuit for responding to the magnet be provided inside the transmitter, which causes an increase in the cost of the transmitter. Further, this configuration requires a magnet for forced transmission.

The transmitter ID learning function disclosed in Japanese Patent Application Laid-Open No. 9-210827 discloses a function of transmitting a transmitter ID registered in the EEPROM that has become unreceivable.
Although it has been proposed that the transmitter ID can be exchanged for another transmitter ID, in this method, the reception ID cannot be received for a certain period of time, and the registered ID is exchanged for another ID received so far. In case of reception error due to external influences such as fading while the vehicle is running, other IDs can be easily obtained.
There was a risk of replacing it.

[0007]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to transmit a special circuit in a tire pressure monitoring system by a simple operation on the receiver side and a forced transmission by changing the pressure. Without setting it on the machine,
Another object of the present invention is to learn the transmitter ID of each tire of a vehicle without using a special tool.

[0008]

A pressure sensor that measures pressure by using a battery as a power supply, a microcomputer that issues a pressure measurement instruction to the pressure sensor at regular intervals, and a unique ID generation element that generates a unique ID number And a transmitter configured with a transmission circuit that converts pressure data measured by the pressure sensor into a transmission waveform, and a transmission antenna that transmits the transmission waveform converted by the transmission circuit to the outside, inside each tire of the vehicle. By mounting, a transmitter for periodically transmitting pressure data inside the tire while the vehicle is running, a receiving antenna for receiving data transmitted from the transmitter, and an RF circuit for converting a received signal into a digital signal A microcomputer for recognizing a reception ID number and pressure data by analyzing a digital signal converted by an RF circuit, and registering the received ID in a receiver A receiver comprising a switch, a RAM for temporarily storing an ID to be registered, an EEPROM for permanently storing an ID number stored in the RAM, and a display device for displaying recognition contents of received data. In a tire pressure monitoring system that is installed near the driver's seat of a vehicle and monitors the air pressure inside the tires of each vehicle, the information received during the ON period of the registration switch of the receiver is received.
D is stored in an EEPROM provided inside the receiver as the ID of the transmitter to be recognized by the receiver, and the pressure data periodically measured by the pressure sensor inside the transmitter is stored immediately before the measurement. When a predetermined pressure difference is generated in comparison with the pressure data, by changing the pairing bit from 0 to 1 and transmitting the data, the receiver can recognize that the transmission is due to the pressure change. The condition for storing the ID of the transmitter to be recognized by the receiver in an EEPROM held inside the receiver is as follows.
By adding a condition that the pairing bit in the received data is 1 to the condition of D, the ID of an arbitrary transmitter can be registered, and the registration switch of the receiver is turned on. Sometimes, by displaying the ID storage position to be registered on the display device, the ID storage position and the transmitter registered in the ID storage position can be determined to which tire is mounted. , As a means for solving the problem.

[0009]

FIG. 1 shows the configuration of a tire pressure monitoring system according to the present invention. FIG. 2 shows a configuration diagram of a transmitter for a tire pressure monitoring system of the present invention. FIG. 3 shows a configuration diagram of a receiver for a tire pressure monitoring system of the present invention. FIG.
FIG. 7 shows the configuration of transmission data according to the present invention. Hereinafter, embodiments of the present invention will be described with reference to the drawings. In FIG. 1, a vehicle 1 has four tires 2, and a transmitter 3 that receives a pressure inside the tires 2 and transmits a radio signal carrying information related to the pressure is provided inside each tire 2. Have been. Each transmitter 3, which respectively also to the transmitter 3 unique unique identification code for verifying the source of the transmission data (ID)
Having. The transmitted signal is received by the receiver 4 installed in a position within a range visible to the driver of the vehicle 1,
It is processed.

In FIG. 2, a microcomputer 5 inside the transmitter 3
Sends a pressure measurement instruction to the pressure sensor 6 at regular intervals, and obtains pressure data from the pressure sensor 6. After performing the measurement at the predetermined interval a predetermined number of times, the pressure data measured at that time and the 2D generated by the unique ID generation element 6a are used.
The 4-bit unique ID is output to the transmission circuit 7, and the transmission circuit 7
And converts the signal into a transmission signal, and transmits the signal to the receiver via the transmission antenna 8. This is usually called periodic transmission. Also,
When the pressure measurement result has changed by a predetermined pressure or more compared with the previous time, the pressure data is immediately transmitted as a pressure abnormality. At this time, the pairing bit included in the transmission data is changed from 0 to 1 and transmitted. This is called abnormal transmission.

In FIG. 3, the receiving antenna 9 of the receiver 4
, A received signal is converted into a digital signal by the RF circuit 10, and the converted digital signal is decoded by the microcomputer 11. At this time, the ID code included in the decrypted data is compared with the registration ID stored in the EEPROM 13, and if the ID is the same as the registered ID, the received data is regarded as recognition data and a predetermined process is performed. I do. Then, the processing result is displayed on the display device 14. The contents are various, for example, pressure data included in the received data.

When the registration switch 12 of the receiver 4 is turned ON, the receiver 4 enters a mode for writing the received ID into the EEPROM 13 in an ID registration mode. FIG. 4 shows an example of transmission data from the transmitter. Here, the ID code has a 24-bit length,
It may be 32 bits long. In addition, 1 immediately after the pressure data
Although the bit is a pairing bit, the present invention is not affected regardless of the position of the bit before the sum check of the transmission data.

[0013]

Next, registration control of the tire pressure monitoring system according to the present invention will be described. ID on receiver
When performing the registration, first, the operator sets the receiver 4 in FIG.
Is turned on. In this state, the receiver 4 enters the ID registration mode, and the display device 14
The ID storage position of 3a is displayed. The ID storage position is set from 1 to the number of IDs that can be registered, and the ID storage position displayed on the display device is also updated sequentially from 1. An ID storage area is set in the RAM 13a. Usually, an area for (number of bytes of one ID) × (number of registered IDs) bytes is stored in the RAM 1a.
3a.

Next, the operator depresses the shaft of the air valve of the tire to be registered to release the air inside the tire and change the pressure. By this operation, the transmitter mounted inside the tire detects that a pressure change has occurred inside the tire, and at that time, the transmitter immediately transmits data to the receiver as abnormal transmission. At this time, because of abnormal transmission, the pairing bit included in the transmission data is set to 1 and transmitted.

When the receiver 4 receives the data with the pairing bit set to 1 due to the abnormal transmission, the receiver 4 stores the received ID in the ID storage position (in the RAM 13a) displayed on the display device 14. Store the number temporarily. Then, the next ID storage position is displayed on the display device 14 and waits for data from the next transmitter. In the case of a passenger car, since four tires are usually mounted, the number of registration IDs required for the receiver 4 is also four. Therefore, the worker stores the ID storage position displayed on the display device 14 as 1,
Press the valve core of each tire to change the air pressure inside the tire in the order of registration until updated in order of 2, 3, 4 such as left front wheel, left rear wheel, right front wheel, right rear wheel, etc. It is possible to register. When reception of all four wheels is completed, the display becomes 5 (END). At this time, the previous reception ID number stored in the RAM 13a is written in the EEPROM 13 in which the same area is secured, and the registration is completed. .

When the reception of the four wheels is completed, the EEPRO
The reason for writing into M is that during the registration work (that is, when reception of the four wheels is not completed), the operator turns the registration switch OFF.
In the case of F, this is to clear the registration work up to that time. Next, the flow of the registration control (S1) will be described with reference to the flowchart of FIG. When the receiver 4 receives the data, it is first determined whether the registration switch 12 is on the ON side (S2). On the OFF side, since the mode is not the registration mode, the ID storage position is initialized to 1 and the control is exited (S11).

If the registration switch 12 is ON, it is in the registration mode, so it is determined whether the current ID storage position is 5 (S4). If the ID storage position is 5, the data reception of four wheels has already been completed, and the EEPROM
Since the registration to the server has been completed, the control directly exits (S11). If the ID storage position is 4 or less, it is expected that there will be a transmitter that has not been received since the registration mode was entered, so it is determined whether the pairing bit of the received data is 1 (S5). If the pairing bit is 1, the data has been transmitted abnormally, and the ID number must be stored in the RAM 13a.

However, if there is an ID number already stored, double storage is performed. Therefore, it is determined whether the received ID number is data already stored in the RAM 13a (S6). If the ID number has already been stored, the control exits without storing the ID number (S11). The same ID number is R
If it is not stored in the AM 13a, the received ID number is stored in the current ID storage position (S7). Then, the ID storage position is incremented to indicate the next ID storage position (S8).

As a result, when the ID storage position is 5, since data from the transmitter mounted on each of the four tires has been received, the four types of data stored in the RAM 13a are stored. The ID number is written into the EEPROM 13 (S10). Since the EEPROM 13 is a non-volatile memory, the stored contents are not erased even when the power of the receiver 4 is cut off. The ID registered in the EEPROM 13 is called a registration ID, and the registration operation is an important operation for determining an ID number recognized by the receiver 4. The receiver 4 recognizes only the ID registered here. Even if another ID is received, it is configured to be ignored.

The number of IDs to be registered is as follows for a normal passenger car.
Since it has four tires 2, the number of IDs that can be registered in the EEPROM 13 is also four. When the four IDs are registered, the IDs are written into the EEPROM 13 and the registration operation is completed when the operator turns off the registration switch 12 of the receiver 4. During registration work, ID
The storage position is displayed on the display device 14 connected to the receiver 4, and the number is displayed, so that the registered worker can visually indicate the current ID storage position.

[0021]

As described above, according to the present invention, the EEPROM having the ID received during the ON period of the registration switch of the receiver as the ID of the transmitter to be recognized by the receiver is provided in the receiver. By remembering to
The ID registration operation can be set to the ID registration mode by a simple operation setting of the receiver. When the pressure data periodically measured by the pressure sensor inside the transmitter has a predetermined pressure difference as compared with the pressure data measured immediately before, the pairing bit is changed from 0 to 1. By transmitting data, the receiver can recognize that transmission is due to pressure change, and forced transmission can be performed without adding a special circuit on the transmitter side and without requiring special tools such as magnets. Can be done. Also, the receiver can determine whether the received data is normally transmitted data or abnormally transmitted data. Further, the condition to be stored in the EEPROM inside the receiver as the ID of the transmitter to be recognized by the receiver includes the condition of the data ID received during the ON period of the registration switch of the receiver, and the condition of the data. By adding the condition that the pairing bit of is set to 1, the ID of an arbitrary transmitter can be registered, and even if data transmitted by normal transmission is received during the registration mode, it is registered. Can be eliminated. The registration work of the individual tire can be confirmed by the registration worker himself. Further, when the registration switch of the receiver is ON, the ID registration position to be registered is displayed on the display device, so that the ID registration position and the transmitter registered at the ID registration position are attached to any tire. Can be determined. In other words, it is possible to know which tire has the ID number of the transmitter attached thereto and the ID number of the transmitter registered in the receiver. Thus, the utility of the present invention is very large.

[Brief description of the drawings]

FIG. 1 shows a configuration of a tire pressure monitoring system of the present invention.

FIG. 2 shows a transmitter configuration diagram of the tire pressure monitoring system of the present invention.

FIG. 3 is a configuration diagram of a receiver of the tire pressure monitoring system of the present invention.

FIG. 4 shows a configuration of transmission data of the present invention.

FIG. 5 shows a control flow chart of registration control of the present invention.

[Brief description of reference numerals]

 DESCRIPTION OF SYMBOLS 1 Vehicle 3 Transmitter 4 Receiver 5 Microcomputer 11 Microcomputer 12 Registration switch 13 EEPROM 13aRAM 14 Display device

Claims (4)

[Claims] 1. A pressure sensor that measures pressure using a battery as a power supply, a microcomputer that issues a pressure measurement instruction to the pressure sensor at regular intervals, and a unique ID that generates a unique ID number
A transmitter comprising a generating element, a transmitting circuit for converting pressure data measured by the pressure sensor into a transmitting waveform, and a transmitting antenna for transmitting the transmitting waveform converted by the transmitting circuit to the outside, each tire of the vehicle, By being installed inside, a transmitter that periodically transmits pressure data inside the tire while the vehicle is traveling, a receiving antenna that receives data transmitted from the transmitter, and converts a received signal into a digital signal An RF circuit, a microcomputer that analyzes the digital signal converted by the RF circuit to recognize the reception ID number and pressure data, a registration switch for registering the received ID in the receiver, and temporarily stores the ID to be registered. RAM to store
To permanently store the ID number stored in the RAM.
A tire pressure monitor for monitoring the air pressure inside the tires of each vehicle by installing a receiver including an EPROM and a display device for displaying the recognition content of the received data near a driver's seat of the vehicle. A tire pressure monitoring system, wherein an ID received during an ON period of a registration switch of a receiver in a system is stored in an EEPROM provided inside the receiver as an ID of a transmitter to be recognized by the receiver. 2. When the pressure data periodically measured by the pressure sensor inside the transmitter has a predetermined pressure difference as compared with the pressure data measured immediately before, a specific one of the transmission data The tire pressure monitoring according to claim 1, wherein the receiver can recognize that the transmission is due to a pressure change by transmitting data by changing a bit (hereinafter referred to as a pairing bit) from 0 to 1. system. 3. The receiver according to claim 1, wherein the ID of the transmitter to be recognized by the receiver is stored in an EEPROM provided inside the receiver as a condition during the ON period of the registration switch of the receiver. 3. The tire pressure according to claim 2, wherein an ID of an arbitrary transmitter can be registered by adding a condition that the pairing bit in the received data is 1 to the condition of the received ID. Monitoring system. 4. An ID storage position to be registered is displayed on a display device when the registration switch of the receiver according to claim 1 is ON, whereby the ID storage position and its ID are displayed.
4. The tire pressure monitoring system according to claim 3, wherein it is possible to determine which tire the transmitter registered in the storage position is attached to.