JP3401535B2 - Tire pressure monitoring system - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD 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 a 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 side. Tire pressure detection devices have been proposed so far. Then, these tire pressure monitoring results, the state of the pressure switch, by registering each predetermined individual ID number in the receiver installed in the vehicle, the necessary tire pressure information as a judgment material There is.

For this reason, the ID registration work is very important, and as a method therefor, a receivable ID number is registered in advance on the receiver side, or the magnet proposed in Japanese Patent Laid-Open No. 8-505939 is transmitted. The ID was registered on the receiver side by forcibly transmitting it by a method such as approaching it near the machine. Further, in Japanese Patent Application Laid-Open No. 9-210827, the transmitter ID of the tire pressure warning device is learned and automatically registered I
A method of updating D has been proposed.

[Problems to be Solved by the Invention]

Each of these prior arts is an excellent idea that the tire pressure during running can be monitored by a radio signal to detect the decrease in tire pressure early and send an alarm to the driver's seat. However, a problem is that when the tire manufacturing apparatus is equipped with a tire air pressure alarm device, the inspection process becomes complicated when consistent manufacturing and assembling and inspection are performed on the automobile manufacturing line. That is, if the receivable ID on the receiver side is determined in advance, the transmitter mounting step must be prepared in accordance with the receiver, which increases the cost due to the increase in the number of work steps.

Further, the method of bringing the magnet close to the transmitter enables forced transmission from the transmitter, and I
In the method of enabling re-registration of D, an element circuit for reacting with a magnet must be provided inside the transmitter, which causes a cost increase of the transmitter. Furthermore, this configuration requires a magnet to force the transmission.

Further, the transmitter ID learning function disclosed in Japanese Patent Laid-Open No. 9-210827 discloses a transmitter ID that cannot be received among the transmitter IDs registered in the EEPROM.
It is proposed that it can be exchanged for another transmitter ID.
In the case of this method, since the registered ID is simply not received for a certain period of time and the registered ID is exchanged with another ID that has been received until then, in the case of abnormal reception due to external influence such as fading while the vehicle is running. However, there was a risk of easily exchanging with another ID.

[0007] In order to solve the above problems, the present invention
Has no special circuit in the transmitter, and
Do not use special tools when performing registration, or
Also, if you can not receive it for a certain period of time, registration ID
Exchange your ID for another ID
Is part of the data sent from the transmitter without
The ID number can be registered in the receiver so that each
Learn your transmitter ID The purpose is to do.

[0008]

A pressure sensor that uses a battery as a power source to measure pressure, a microcomputer that issues pressure measurement instructions to the pressure sensor at regular intervals, and a unique ID generation element that generates a unique ID number. A transmitter circuit that converts pressure data measured by a pressure sensor into a transmission waveform, and a transmitter antenna that transmits the transmission waveform converted by the transmission circuit to the outside. By mounting, a transmitter that periodically transmits the pressure data inside the tire while the vehicle is running, a receiving antenna that receives the data transmitted from the transmitter, and an RF circuit that converts the received signal into a digital signal. And a microcomputer for recognizing the received ID number and pressure data by analyzing the digital signal converted by the RF circuit, and registration for registering the received ID in the receiver. A receiver including 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 installed near the driver's seat of a vehicle for the purpose of monitoring the air pressure inside the tire of each vehicle, I received during the ON period of the registration switch of the receiver.
D is stored in the EEPROM 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 measured immediately before. When a predetermined pressure difference is generated in comparison with the generated 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. Then, as a condition for storing the ID of the transmitter to be recognized in the receiver in the EEPROM inside the receiver, I received during the ON period of the registration switch of the receiver.
By adding the condition that the pairing bit in the received data is 1 to the condition of D, the ID of any transmitter can be registered, and the registration switch of the receiver is turned on. At this time, by displaying the ID storage position to be registered on the display device, it is possible to determine which tire is equipped with the ID storage position and the transmitter registered in the ID storage position. , As a solution to the problem.

[0009]

FIG. 1 shows the configuration of a tire pressure monitoring system of the present invention. FIG. 2 shows a block 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. Figure 4
The structure of the transmission data of the present invention is shown in FIG. Embodiments of the present invention will be described below with reference to the illustrated examples. In FIG. 1, a vehicle 1 has four tires 2, and inside each of the tires 2, a transmitter 3 for transmitting a wireless signal for receiving the internal pressure of the tire 2 and carrying information related to the pressure is provided. Has been. Each transmitter 3, which respectively also to the transmitter 3 unique unique identification code for verifying the source of the transmission data (ID)
Have. 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, the 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 the measurement at the fixed intervals is performed a predetermined number of times, the pressure data measured at that time and the 2 generated by the unique ID generating element 6a are measured.
The 4-bit unique ID is output to the transmission circuit 7 and the transmission circuit 7
Is converted into a transmission signal and transmitted to the receiver via the transmission antenna 8. This is usually called a periodical transmission. Also,
When the pressure measurement result changes more than the predetermined pressure as compared with the previous time, it is determined that the pressure is abnormal, and the pressure data is immediately transmitted. At this time, the pairing bit included in the transmission data is changed from 0 to 1 and transmitted. This is called an abnormal transmission.

In FIG. 3, the receiving antenna 9 of the receiver 4 is shown.
Then, the 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 registered 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. To do. Then, the content result of the processing is displayed on the display device 14. The contents thereof 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 is in an ID registration mode, which is a mode for writing the received ID in the EEPROM 13. FIG. 4 shows an example of transmission data from the transmitter. Here, the ID code has a length of 24 bits,
The length may be 32 bits. 1 immediately after the pressure data
Although the bit is a pairing bit, it does not affect the present invention wherever the bit is located before the sum check of the transmission data.

[0013]

Next, the registration control of the tire air pressure monitoring system according to the present invention will be described. ID to receiver
At the time of registration, the worker first receives the receiver 4 in FIG.
The registration switch 12 is turned on. In this state, the receiver 4 is in the ID registration mode and the display device 14 is in the RAM 1
The ID storage position of 3a is displayed. The ID storage positions are set from 1 to the number of IDs that can be registered, and the ID storage positions displayed on the display device are also sequentially updated from 1. An ID storage area is set in the RAM 13a, and an area for (number of bytes of one ID) × (number of registered IDs) bytes is usually RAM1.
3a.

Next, the worker depressurizes the air valve of the tire to be registered and depressurizes the air inside the tire to 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 an 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 in which the pairing bit is set as 1 due to the abnormal transmission, the receiver 4 receives the ID received in the ID storage position (inside 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 the next data from the transmitter is awaited. In the case of a passenger car, since four tires are normally mounted, the number of registration IDs required for the receiver 4 is four. Therefore, the worker can confirm that the ID storage position displayed on the display device 14 is 1,
Press the valve core of each tire to change the air pressure inside the tire in the order of registration until it is updated in the order of 2, 3, 4, for example, left front wheel, left rear wheel, right front wheel, right rear wheel. It is possible to register. When the reception of all four wheels is completed, the display becomes 5 (END), and at this time, the reception ID numbers stored so far in the RAM 13a are written in the EEPROM 13 in which the same area is secured, and the registration is completed. .

When the reception of four wheels is completed, EEPRO
The reason for writing to M is that the operator turns off the registration switch while the registration work is in progress (that is, when reception of the four wheels is not completed).
This is because, when F is selected, the registration work up to that point is cleared. Next, the flow of registration control (S1) will be described using 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). If it is OFF, it is not in the registration mode, so 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, and it is determined whether the current ID storage position is not 5 (S4). If the ID storage position is 5, the data reception for the four wheels has already been completed, and the EEPROM
Since the registration to is completed, the control is exited as it is (S11). If the ID storage position is 4 or less, it is expected that there is an unreceived transmitter after entering the registration mode, so it is determined whether the pairing bit of the received data is 1 (S5). If the pairing bit is 1, the data is abnormally transmitted, so the ID number must be stored in the RAM 13a.

However, if there is an already stored ID number, it will be double-stored, so it is judged whether the received ID number is the data already stored in the RAM 13a (S6). Then, if the ID number is already stored, the control is exited without storing (S11). The same ID number is R
If not stored in the AM 13a, the received ID number is stored in the ID storage position at that time (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, it means that the data from the transmitters mounted on the tires of the four wheels have been received, so that the four types of data stored in the RAM 13a are stored. The ID number is written in the EEPROM 13 (S10). Since the EEPROM 13 is a non-volatile memory, the stored contents are not erased even if the power of the receiver 4 is cut off. The ID registered in the EEPROM 13 is called a registered ID, and the registration work is an important work for determining the 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.

[0020] The number of IDs to be registered is in the case of a normal passenger car,
Since it has four tires 2, the number of IDs that can be registered in the EEPROM 13 is four. When the four IDs are registered, the IDs are written in the EEPROM 13, and the worker turns off the registration switch 12 of the receiver 4 to complete the registration work. During the registration work, ID as described above
The number of the storage position is displayed on the display device 14 connected to the receiver 4, and the current ID storage position can be visually shown to the registered operator.

[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 in the receiver is provided in the inside of the receiver. By remembering
The ID registration work can be switched 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 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 it is a pressure change transmission, and forced transmission without adding a special circuit on the transmitter side or requiring a special tool such as a magnet Can be done. Further, the receiver side can also judge whether the received data is normally transmitted data or abnormally transmitted data. Furthermore, as a condition for storing in the EEPROM inside the receiver as the ID of the transmitter to be recognized by the receiver, the condition is the data ID received during the ON period of the registration switch of the receiver, and By adding the condition that the pairing bit of 1 is 1, the ID of any transmitter can be registered, and even if the data transmitted by normal transmission during the registration mode is received, it will be registered. It can be resolved. In addition, the registration work of the individual tires 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 tire to which the ID registration position and the transmitter registered at the ID registration position are attached. It can be determined whether or not there is. That is, it is possible to know which tire has the ID number of the transmitter attached to which tire registered as the ID in the receiver. As described above, the practicality of the present invention is extremely great.

[Brief description of drawings]

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

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

FIG. 3 shows a receiver block diagram of the tire pressure monitoring system of the present invention.

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

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

[Simple explanation of symbols]

1 vehicle 3 transmitter 4 receiver 5 Microcomputer 11 Microcomputer 12 Registration switch 13 EEPROM 13a RAM 14 Display

Claims (3)

(57) [Claims] 1. Mounting inside each tire of a vehicle
As a result, the pressure data inside the tire is regularly
A pressure sensor that measures pressure by using a battery as a power source for the transmitter that transmits
And the pressure sensor to send pressure measurement instructions at regular intervals.
And a unique ID generation element for generating a unique ID number
And convert the pressure data measured by the pressure sensor into a transmission waveform.
The transmission circuit to be converted and the transmission waveform converted by the transmission circuit
It is configured with a transmission antenna that transmits to the other part, while it is installed near the driver's seat of the vehicle and transmitted from the transmitter
The receiver that receives the received data with the receiving antenna.
RF circuit that converts the received signal to digital signal, and RF
Received ID number by analyzing the digital signal converted by the circuit
And a microcomputer that recognizes pressure data and the reception ID number
Switch for registering with the receiver and I
The RAM that temporarily stores the D number and the RAM that is stored in the RAM
The EEPROM that permanently stores the ID number
Display device that displays the recognition contents of the data
The purpose is to monitor the air pressure inside the tires of each vehicle.
In the tire pressure monitoring system, the reception ID number received during the ON period of the registration switch of the receiver
The ID number of the transmitter that the receiver should recognize.
Stored in the EEPROM inside the receiver as
And, the ON period of the registration switch of a receiver, the interior of the transmitter
The pressure data regularly measured by the pressure sensor of
Compare the pressure data measured immediately before with the specified pressure difference.
If it occurs, the packet that is a specific 1 bit in the transmitted data
Change the alling bit from 0 to 1 and send data
This allows the receiver to recognize that the transmission is due to a pressure change.
A tire pressure monitoring system characterized by being able to recognize. 2. The receiver according to claim 1,
I of the transmitter to be recognized by the receiver In the receiver as D
As a condition for storing in the EEPROM of the department
Received ID number received during ON period of the registration switch of the receiver
In addition, the pairing in the received data
By adding the condition that the bit is 1
The feature is that the ID of any transmitter can be registered.
The tire pressure monitoring system according to claim 1. 3. The registration switch of the receiver described in claim 1 is
When ON, the registration ID number you are trying to register
By displaying the delivery position on the display device, the registration ID number
Storage location and transmitter registered in its ID storage location
It is possible to determine which tire the
The tire pressure monitoring system according to claim 2, which is a characteristic of the tire pressure monitoring system.