JP4585357B2 - Tire information transfer device, tire information transfer method, and vehicle - Google Patents

Description

  The present invention relates to a tire information transfer device, a tire information transfer method, and a vehicle that transfer information of an RFID tag provided on a tire to a vehicle body side.

  In recent years, RFID (Radio Frequency Identification) tags that can transmit and receive data in a contactless manner despite being extremely small are known. Such an RFID tag can be used in various fields. For example, by attaching an RFID tag to each tire of a vehicle, information on each tire can be used in a vehicle control device or via an external network. A technique used at a store or a maintenance factory is known (see Patent Document 1). And in this technique, in order to assist communication from each RFID tag provided in each tire to a control device provided in the approximate center of the vehicle, it plays the role of a relay base between each RFID tag and the control device. An auxiliary communication device is provided.

Japanese Patent Laying-Open No. 2004-13449 (paragraph 0027, FIG. 5)

  However, in the conventional technique, a dedicated auxiliary communication device having only a function of assisting communication from each RFID tag to the control device is newly provided, which is not preferable in terms of cost and installation space.

  Therefore, in the present invention, a tire information transfer device and a tire that can achieve cost reduction and space saving by assisting communication from the RFID tag of each tire to the vehicle body side without providing a new auxiliary communication device. An object is to provide an information transfer method and a vehicle.

The invention according to claim 1 of the present invention that solves the above-mentioned problems is a reading means for reading information related to a tire stored in an RFID tag provided on a tire of a vehicle, and transferring the read information to the vehicle body side. A tire information transfer apparatus comprising: a transfer means for transferring the read information to a vehicle body side using a tire pressure monitoring system device provided in the vehicle as the transfer means; and the tire pressure monitoring system. The device is an air pressure detection unit provided on a wheel for holding the tire in order to detect the air pressure of the tire and transmit the detected signal to the vehicle body side, and the reading means includes the reading unit. It is characterized by providing .

  Here, the “tire pressure monitoring system” refers to a system that transmits tire pressure detected by a sensor provided on the tire side to the vehicle body side.

According to the first aspect of the present invention, information read by the reading means from the RFID tag provided on the tire is transferred to the vehicle body side via the equipment of the tire pressure monitoring system. That is, since the tire information transfer device and the tire pressure monitoring system share one communication facility, it is necessary to provide a new auxiliary communication device dedicated to the RFID tag in a vehicle equipped with the tire pressure monitoring system. Disappear.
Further, the tire information transfer device and the tire pressure monitoring system can share the air pressure detection unit as a communication facility.

Invention of Claim 2 is the tire information transfer apparatus of Claim 1 , Comprising: The said air pressure detection unit is provided on the outer peripheral surface of the said wheel, and is provided on the inner peripheral surface of the said tire. The RFID tag is configured to face the RFID tag.

  Here, “opposite” refers to the radial direction in the space formed by the inner surface of the tire and the outer peripheral surface of the wheel, with the RFID tag and the air pressure detection unit intervening nothing between them. It means that they are lined up.

According to the second aspect of the present invention, since the air pressure detection unit and the RFID tag communicate with each other with nothing interposed therebetween, the communication performance can be improved.

According to a third aspect of the present invention, there is provided a vehicle including the tire information transfer device according to the second aspect , wherein the tire is provided with positioning means for causing the RFID tag to face the air pressure detection unit. It is characterized by.

  Here, the “positioning means” means, for example, a marker for adjusting the position while being visually recognized by an operator, or a keyway for fixing the position in the circumferential direction of the tire with respect to the wheel by engaging with a protrusion formed on the wheel. Such as a recess.

According to the invention described in claim 3 , since the RFID tag provided on the inner peripheral surface of the tire is opposed to the air pressure detection unit attached to the wheel by the positioning means, the air pressure detection unit and the RFID tag The communication distance can be always kept constant, and the reliability of the communication performance can be improved.

The invention according to claim 4, to detect the air pressure of the tire, in order to transmit the detected signal to the vehicle body, is provided on the tire of a vehicle including the air pressure detecting unit provided to the wheel for holding the tire the information related to the tires stored in the RFID tag, a tire information transfer method for transferring to the vehicle body, the information of the RFID tag read by the provided reading means to the air pressure detecting unit, read the The information is transferred to the vehicle body side using the air pressure detection unit as a transfer means .

According to the fourth aspect of the invention, after the information of the RFID tag provided on the tire is read by the reading means provided in the air pressure detection unit , the information is transferred to the vehicle body side using the air pressure detection unit as the transfer means . That is, according to this method, since the communication of the tire information from the RFID tag performed using the communication facilities of the air pressure detecting unit, in a vehicle mounted with the air pressure detecting unit, a new auxiliary communication RFID tag dedicated There is no need to provide a vessel.

In claim 1 or a claim structure described in Item 4, in the vehicle mounted with the air pressure detecting unit, without providing a new auxiliary communication unit of the RFID tag dedicated utilizes air pressure detecting unit Since communication can be assisted, cost reduction and space saving can be achieved.

According to the second aspect of the present invention, since the air pressure detection unit and the RFID tag communicate with each other with nothing interposed therebetween, the communication performance can be improved.

According to the third aspect of the present invention, since the RFID tag is opposed to the air pressure detection unit by the positioning means, the communication distance between the air pressure detection unit and the RFID tag can always be kept constant, and the reliability of the communication performance can be maintained. Can increase the sex.

  Next, embodiments of the present invention will be described in detail with reference to the drawings as appropriate. In the drawings to be referred to, FIG. 1 is a plan view showing a vehicle equipped with a tire reading device and a tire pressure monitoring system, FIG. 2 is a block diagram showing details of an RFID tag, a sensor unit, and an ECU group, and FIG. It is explanatory drawing which shows the detail of the sensor unit provided in a RFID tag and a wheel.

  As shown in FIG. 1, the tire information transfer device 1 has a function of reading information from an RFID tag 2 provided on each tire T of the vehicle C, and an ECU group provided on the vehicle body side of the vehicle C. (Control device) 3 has a function of transferring to the controller 3. Specifically, the tire information transfer device 1 adds a function of reading information of the RFID tag 2 to an existing tire pressure monitoring system (hereinafter referred to as “TPMS”) 4, thereby communicating with the communication device (transfer) of the TPMS 4. The information is transferred using a means.

[TPMS]
Below, the detail of TPMS4 which functions also as the tire information transfer apparatus 1 is demonstrated.
The TPMS 4 includes a sensor unit (air pressure detection unit) 41 mounted on a wheel W that holds each tire T, an initiator 42 provided on the vehicle body side, an ECU group 3, and a monitor 43.

[Sensor unit]
As shown in FIG. 2, the sensor unit 41 includes a pressure sensor 41a that directly measures the pressure in the pneumatic chamber of the tire T, a temperature sensor 41b that detects the temperature in the pneumatic chamber, a CPU (Central Processing Unit) 41c, In addition to the memory 41d and the vehicle-mounted transceiver 41e for communicating with the ECU group 3, the vehicle includes a tire-based transceiver (reading means) 41f for communicating with the RFID tag 2. The sensor unit 41 includes a battery 41g, and is activated (or stopped) upon receiving a radio signal from the initiator 42. Further, as shown in FIG. 3, the sensor unit 41 is configured integrally with a valve B attached to the rim R of each wheel W, and is attached to the outer peripheral surface of the rim R.

  Specifically, the sensor unit 41 is activated when an activation signal from the initiator 42 is received by the transceiver 41e for the vehicle body, and the air pressure and temperature detected by the sensors 41a and 41b by the CPU 41c, and the memory 41d. An identification code (ID set for each sensor unit 41) recorded in advance is associated with each other, and these signals are wirelessly transmitted to the ECU group 3 via the initiator 42. The sensor unit 41 functions as a transponder by wirelessly transmitting the activation signal from the transceiver 41f for tire to the RFID tag 2 when the activation signal from the initiator 42 is received by the transceiver 41e for the vehicle body. The RFID tag 2 is activated and a response signal from the RFID tag 2 is received. When the sensor unit 41 receives the response signal in this way, the sensor unit 41 wirelessly transmits the response signal to the ECU group 3 via the initiator 42, thereby functioning as a transfer unit of the tire information transfer device 1. ing. Here, as a method of stopping the sensor unit 41 activated in this way, for example, a method of causing the CPU 41c to stop after a predetermined time has elapsed since activation, or a method of stopping based on a stop signal from the initiator 42 may be adopted. It may be adopted. By adopting such a method, consumption of the battery 41g can be suppressed.

  Note that the communication between the sensor unit 41 and the RFID tag 2 described above is preferably performed at a frequency (2.45 GHz band microwave) compliant with the international standard (ISO 18000-4) from the viewpoint of versatility. Needless to say, it can be changed. In addition, the communication between the ECU group 3 and the initiator 42 and the communication between the initiator 42 and the sensor unit 41 have a frequency of 315 MHz or 433 MHz so that communication can be satisfactorily performed even if there is a shield such as a vehicle body panel. Although it is desirable to use (UHF) wave communication, it goes without saying that it can be changed as appropriate.

〔initiator〕
The initiator 42 serves as a relay base and functions to instruct the start (or stop) of the sensor unit 41 described above, and is attached to the inside of the wheel housing that covers the tire T. In the present embodiment, the communication between the sensor unit 41 and the ECU group 3 is performed via the initiator 42. However, the present invention is not limited to this, and the sensor 42 is removed from the structure of the present embodiment. The unit 41 and the ECU group 3 may communicate directly.

[ECU group]
The ECU group 3 includes a transmitter / receiver 31, a TPMS ECU 32, a VSA ECU 33, and the like, and the transmitter / receiver 31 and the TPMS ECU 32 function as the TPMS 4. Specifically, when receiving information indicating the air pressure, temperature, and identification code from the sensor unit 41 via the transmitter / receiver 31, the TPMS ECU 32 determines the air pressure in the tire T at a predetermined position (for example, the front left) based on the information. The air pressure is determined as to whether the “normal state” is within the specified range or the “abnormal state” is not. Further, when the TPMS ECU 32 determines that the state is “abnormal state”, the result is displayed on the monitor 43 shown in FIG. 1 to notify the driver. The TPMS ECU 32 includes a communication unit, a storage unit, a CPU, and the like. In the storage unit, data indicating the correspondence between the identification code (sensor ID) and each wheel is stored in advance.

  When the TPMS ECU 32 receives a response signal (hereinafter also referred to as “tire information”) of the RFID tag 2 from the sensor unit 41 via the transceiver 31, the TPMS ECU 32 sends the signal to the VSA ECU 33 or other via the in-vehicle harness. It also has a function of transmitting to the control device, specifically CAN (Controller Area Network) transmission. The VSA ECU 33 that has received such a signal realizes good VSA (Vehicle Stability Assist) control by switching the control gain to the control gain corresponding to the tire information and performing brake control and engine output control. It is possible. The VSA ECU 33 includes a communication unit, a storage unit, a CPU, and the like, and tire information (for example, tire ID) and data indicating the correspondence between the wheels are stored in advance in the storage unit.

〔monitor〕
As shown in FIG. 1, the monitor 43 visually displays the result of air pressure determination to notify the occupant. In addition to the result of air pressure determination, the monitor 43 includes information derived from tire information in the RFID tag 2 (for example, the tire T calculated from the type of tire T such as studless or normal, the date of manufacture, etc.). May be displayed.

[RFID tag]
Subsequently, the details of the RFID tag 2 that is a reading target of the tire information transfer apparatus 1 will be described.
As shown in FIG. 3, the RFID tag 2 is a long component comprising a printed antenna 21 formed by using a printing technique and an IC chip 22 connected to the printed antenna 21. is there. And this RFID tag 2 is affixed on the tread back surface (inner peripheral surface) T1 of the tire T so as to be substantially at the center in the width direction and along the circumferential direction. In addition, the tire T to which the RFID tag 2 is attached is provided with a marker (positioning means) M for positioning the valve B in the vicinity of the attachment position of the RFID tag 2 on the side surface T2. In addition, what is necessary is just to use a paint, a seal-like thing, etc. as this marker M, and what is necessary is just to make those colors different from the color of the tire T (for example, yellow). When the tire T is attached to the wheel W, the RFID tag 2 in the tire T and the sensor unit 41 attached to the wheel W are fitted to the tire T by matching the marker M with the valve B in the radial direction. In T, it opposes in the state which a shield does not interpose.

  The tire T generally has a non-uniform weight in the circumferential direction due to manufacturing reasons. Therefore, the lightest part of the tire T and the heavy part in the circumferential direction of the wheel W (valve B) The tire T and the wheel W are assembled in consideration of the rotational balance. Therefore, if such a light part of the tire T is used as a positioning means and the RFID tag 2 is provided at that position, the valve can be used when the tire T and the wheel W are assembled without newly providing a positioning means. The sensor unit 41 integrated with B and the RFID tag 2 can be opposed to each other.

  As shown in FIG. 2, the IC chip 22 constituting the RFID tag 2 includes a memory 22a, a CPU 22b, and a transceiver 22c. Information related to the tire T (for example, information such as tire ID, brand, size, μ slip characteristics, cornering power characteristics, date of manufacture, serial number, tire type such as studless or normal) is recorded in the memory 22a. Has been. The transmitter / receiver 22c is provided with a power generation unit 22d, which generates power when the RFID tag 2 receives a radio wave from the sensor unit 41, and starts with the power. And CPU22b has the function to transmit the information currently recorded on the memory 22a to the sensor unit 41 via the transmitter / receiver 22c, if the transmitter / receiver 22c receives a starting signal from the sensor unit 41. Since the RFID tag 2 does not have a battery, it receives radio waves from the reader (sensor unit 41), converts the radio waves into electric power, and operates, so that it is battery-less.

  Next, operations of the TPMS 4 and the tire information transfer apparatus 1 will be described with reference to FIG. In the drawings to be referred to, FIG. 4 is a flowchart showing operations of the TPMS and the tire information transfer device.

  As shown in FIG. 4, when the ignition switch is turned on, the TPMS ECU 32 and the VSA ECU 33 are activated (START). The TPMS ECU 32 performs a predetermined initial TPMS diagnosis for checking whether or not each device of the TPMS 4 is normal (step S1), and then activates the sensor unit 41 via the initiator 42 (step S2).

  When activated, the sensor unit 41 first reads the air pressure and temperature detected by the pressure sensor 41a and the temperature sensor 41b (step S11). Thereafter, the sensor unit 41 transmits a start signal to the RFID tag 2 to transmit tire information from the RFID tag 2 (step S21), and reads the tire information (step S12). After step S12, the sensor unit 41 attaches an identification code (sensor ID) to the information indicating the read air pressure and temperature and tire information, and transmits them to the TPMS ECU 32 (step S13). After step S13, the operation of the sensor unit 41 is stopped after a lapse of a predetermined time or by a stop signal from the initiator 42.

  When receiving the various information described above (step S3), the TPMS ECU 32 determines whether the air pressure of each tire T is “normal state” or “abnormal state” based on the information indicating the air pressure and temperature and the identification code. Predetermined air pressure alarm processing for determining whether or not there is is executed (step S4). In this step S4, if it is determined that the state is “normal state”, the process proceeds to the next step without doing anything, and if it is determined that the state is “abnormal state”, the monitor 43 is turned on. After notifying an occupant of an abnormality through the control, control is performed such that the process proceeds to the next step.

  Then, after exiting step S4, the TPMS ECU 32 transmits the tire information to the VSA ECU 33 and other control devices via the in-vehicle harness (step S5). After step S5, the TPMS ECU 32 returns to START again (RETURN), but since the TPMS initial diagnosis (step S1) has already been completed, the processing of steps S2 to S5 is not performed after that. Repeat only.

  When receiving the tire information from the TPMS ECU 32 (step S31), the VSA ECU 33 changes the control gain based on the tire information (step S32). That is, for example, when the VSA ECU 33 acquires a tire brand as tire information, the control gain is changed to a control gain corresponding to the tire brand (tire performance). As a result, even when traveling on the snow surface, which has the same conditions, with different brand tires, VSA control is executed with a control gain corresponding to each tire brand, so that the running performance of the vehicle is made uniform. Will be guaranteed. Incidentally, since step S32 is a well-known control flow in which VSA control is executed when predetermined conditions are met, illustration and description thereof are omitted.

According to the above, the following effects can be obtained in the present embodiment.
Since the tire information of the RFID tag 2 is transmitted to the VSA ECU 33 or the like by using a part of the existing TPMS 4, it is not necessary to provide a new auxiliary communication device dedicated to the RFID tag 2, thereby reducing costs and saving space. Can be achieved.
Since the RFID tag 2 can be opposed to the sensor unit 41 by the marker M, the communication distance between the RFID tag 2 and the sensor unit 41 can always be kept constant, and the reliability of the communication performance can be improved. .

Since the RFID tag 2 is mounted inside the tire T, the RFID tag 2 is not affected by water, dust, ultraviolet rays, stepping stones, etc., and the reliability can be improved accordingly.
Since both the RFID tag 2 and the sensor unit 41 are provided inside the tire T, communication between the two is not affected by external electromagnetic waves, and the communication reliability can be improved correspondingly. Moreover, since the transmission / reception radio wave between the two is less likely to leak outside the tire, it is possible to suppress adverse effects on the external environment.

By attaching the RFID tag 2 to the inside of the tire T, the RFID tag 2 is not subjected to an external load, so that the possibility of dropping or theft can be extremely reduced.
Since the RFID tag 2 is attached to the tread back surface T1 of the tire T, when attaching the tire T to the wheel W, the RFID tag 2 can be protected by the sidewall of the tire T, and the RFID tag 2 is prevented from being damaged. can do.

  Since the RFID tag 2 is provided at the center in the width direction of the tread back surface T1, it can be easily accessed from the outside by a dedicated reader / writer, and tire information can be easily read / rewritten by this dedicated reader / writer.

In addition, this invention is implemented in various forms, without being limited to the said embodiment.
In the present embodiment, the tire information read from the RFID tag 2 is transmitted from the sensor unit 41 to the ECU group 3 via the initiator 42. However, the present invention is not limited to this, for example, instead of the initiator 42, the wheel W Tire information may be transmitted through the booster by providing a booster that amplifies and transmits the signal at the center.

  In the present embodiment, the initiator 42 is used as a relay base. However, the present invention is not limited to this. For example, when the sensor unit 41 and the ECU group 3 are directly communicated, the initiator 42 and the ECU group 3 are connected to the in-vehicle harness. The initiator 42 may be used only for starting / stopping the sensor unit 41.

  In the present embodiment, the tire information transfer device 1 has a function of only reading the tire information in the RFID tag 2. However, the present invention is not limited to this, and information transmitted from the ECU group 3 is transmitted to the RFID tag 2. You may have the function to write in. In this case, the CPU 41c of the sensor unit 41 has a function of transmitting a signal transmitted from the ECU group 3 to the RFID tag 2 and is transmitted from the sensor unit 41 to the CPU 22b of the RFID tag 2. A function of writing a signal to the memory 22a may be provided.

It is a top view which shows the vehicle carrying a tire reader and a tire pressure monitoring system. It is a block diagram which shows the detail of a RFID tag, a sensor unit, and ECU group. It is explanatory drawing which shows the detail of the RFID tag provided in a tire, and the sensor unit provided in a wheel. It is a flowchart which shows operation | movement of TPMS and a tire information transmission apparatus.

Explanation of symbols

1 Tire Information Transfer Device 2 RFID Tag 3 ECU Group (Control Device)
32 TPMSECU
33 VSAECU
4 TPMS
41 Sensor unit (pneumatic pressure detection unit, transfer means)
41a Pressure sensor 41b Temperature sensor 41f Transmitter / receiver for tire (reading means)
B Valve C Vehicle M Marker (Positioning means)
T tire T1 back of tread (inner surface)
W wheel R rim

Claims (4)

A tire information transfer device comprising: reading means for reading information related to a tire stored in an RFID tag provided on a tire of a vehicle; and transfer means for transferring the read information to the vehicle body side,
Transfer the read information to the vehicle body side using a tire pressure monitoring system device provided in the vehicle as the transfer means ,
The tire pressure monitoring system equipment is:
An air pressure detection unit provided on a wheel for holding the tire in order to detect the air pressure of the tire and transmit the detected signal to the vehicle body;
A tire information transfer device , wherein the air pressure detection unit is provided with the reading means . 2. The tire according to claim 1 , wherein the air pressure detection unit is provided on an outer peripheral surface of the wheel and is configured to face the RFID tag provided on an inner peripheral surface of the tire. Information transfer device. A vehicle comprising the tire information transfer device according to claim 2 ,
The vehicle, wherein the tire is provided with positioning means for causing the RFID tag to face the air pressure detection unit. Detecting the tire pressure, in order to transmit the detected signal to the vehicle body, associated with a tire which is stored in an RFID tag provided in the tire of a vehicle including the air pressure detecting unit provided to the wheel for holding the tire the information, a tire information transfer method for transferring to the vehicle body,
A tire information transfer method , wherein information of the RFID tag is read by a reading unit provided in the air pressure detection unit, and the read information is transferred to the vehicle body side using the air pressure detection unit as a transfer unit .

Images