JP2008112372A - Wheel status monitoring system and wheel information transmitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology for reducing power consumption of a battery for driving a device for transmitting wheel information. <P>SOLUTION: A TPMS valve 20 transmitting air pressure information includes an air pressure sensor 21 for detecting air pressure, a wheel side transceiver 22 for transmitting an ID code and a first wheel signal including the air pressure information and for receiving a second wheel signal transmitted from the other TPMS valve 20, and a control circuit 23. The control circuit 23, when determining its own wheel is one of double tires, enters a transmission power saving mode for making transmission output smaller than preset standard output so that the first wheel signal reaches the wheel side transceiver 22 provided on the other of the double tires, and, when determining its own wheel is the other of the double tires, enters a relay signal transmission mode for transmitting at least a part of the second wheel signal transmitted from the other TPMS valve 20 provided on the other wheel of the double tires and received by the wheel side transceiver 22. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a technology of a device capable of transmitting wheel information related to a wheel.

  If the vehicle is run for a long time with the tire at a low pressure or a high temperature, the reliability of the tire may be impaired. Therefore, a technique for appropriately monitoring the air pressure, temperature and other conditions of the tire is desired. In order to know the state of each tire, a technique is known in which a sensor and a transmitter are provided in each tire, and information such as air pressure detected by the sensor is transmitted to a receiver on the vehicle body side by the transmitter.

In Patent Document 1, when a trigger signal received from the vehicle body side is received, a wheel-side transceiver that transmits a detection signal corresponding to the tire air pressure detected by the sensing unit, and the tire air pressure based on the detection signal are disclosed. There is disclosed a tire air pressure detecting device including a vehicle body side transmitter / receiver that calculates Patent Document 2 discloses a wheel information processing apparatus that transmits output signals of a plurality of sensors provided on one wheel to a repeater and transmits the output signal from the repeater to the vehicle body side communication device.
JP 2006-111158 A JP-A-2005-100100

  The air pressure sensor unit used in the apparatus for detecting an abnormality in the tire air pressure as described above is obtained from a power source such as a battery provided with power necessary for transmitting detection information. Therefore, when the power of the battery (battery) decreases, it is necessary to remove the wheel from the vehicle body and further replace the air pressure sensor unit itself or the battery.

  In particular, in the case of a vehicle having a so-called double tire in which a plurality of tires are provided in parallel, such as a truck or a freight car having more wheels than a normal four-wheel vehicle, replacement work in a vehicle having a normal single tire Compared to the above, the work load in the replacement work increases due to the fixed position of the wheel and the tire size. Therefore, it is required to reduce the power consumption of the battery that drives the air pressure sensor unit as much as possible.

  The present invention has been made in view of such a situation, and an object of the present invention is to reduce power consumption of a battery that drives a device that transmits wheel information related to wheels such as tire air pressure and temperature. Another object of the present invention is to provide a technique capable of suppressing the replacement frequency of a battery that drives the device.

  In order to solve the above-described problems, a wheel state monitoring system according to an aspect of the present invention includes a plurality of wheel information transmission devices capable of transmitting wheel information related to wheels, and a wheel information processing device that receives and processes the wheel information. Is a wheel state monitoring system that monitors the state of a wheel by transmitting and receiving information, wherein the wheel information transmitting device identifies a detection unit that detects the wheel information and its own wheel from other wheels. For transmitting the first wheel signal including the identification information and the wheel information, and the second wheel signal including the other identification information and other wheel information transmitted from the other wheel information transmitting device. And a wheel-side control unit that can determine whether its own wheel is one of the double tires or the other. The wheel information processing device includes a vehicle body side receiving unit that receives a signal including the wheel identification information and the wheel information transmitted from the wheel information transmission device, and the wheel identification information and the wheel information. And a vehicle body side control unit that estimates the state of the wheel on which the wheel information transmission device is provided. The wheel-side control unit in the wheel information transmission device of a wheel that has been determined that its own wheel is one of the double tires among the plurality of wheel information transmission devices, the wheel provided in the other of the double tires in the first wheel signal Transition to a power saving transmission mode in which the transmission output in the wheel side transmission unit is smaller than a predetermined reference output to the extent that it reaches the side reception unit, and the own wheel of the plurality of wheel information transmission devices is the other of the double tires The wheel-side control unit in the wheel information transmission device of the wheel determined as follows: at least the second wheel signal transmitted from the wheel information transmission device that has shifted to the power-saving transmission mode and received by the wheel-side reception unit. A transition is made to a relay signal transmission mode in which a part is transmitted to the wheel information processing apparatus.

  Here, the wheel information related to the wheels includes, for example, information that affects the running of the vehicle and the durability of the wheels, such as tire air pressure and temperature. Further, the wheel information transmitting device may be able to transmit the detected wheel information together with the identification information of the own wheel periodically or at a predetermined timing. Further, the wheel side transmitter and the wheel side receiver may be separate devices or may be integrated communication devices.

  When the own wheel is one of the double tires, a signal may be transmitted directly to the wheel information processing device, but the wheel is transmitted via another wheel information transmitting device provided on the wheel constituting the other of the double tire. You may transmit to an information processing apparatus. In that case, the 1st wheel signal transmitted from a wheel information transmitter should just arrive at the wheel side receiving part with which the wheel which constitutes the other of the double tire arranged in the neighborhood in parallel with the self wheel is equipped. A transmission output that reaches the wheel information processing apparatus is not necessarily required.

  So, according to the above-mentioned aspect, in the wheel information transmission device of the wheel in which the own wheel was determined to be one of the double tires by the wheel side control unit among the plurality of wheel information transmission devices, the wheel information transmission device is provided. The wheel side control unit can make the transmission output in the wheel side transmission unit smaller than a predetermined reference output to such an extent that the first wheel signal reaches the wheel side reception unit provided in the other of the double tires. Moreover, in the wheel information transmission device of the wheel determined by the wheel side control unit among the plurality of wheel information transmission devices that the wheel is the other of the double tires, the wheel side control unit provided in the wheel information transmission device, At least a part of the second wheel signal transmitted from the wheel information transmitting device that has shifted to the power saving transmission mode and received by the wheel-side receiving unit can be transmitted to the wheel information processing device. Here, the predetermined reference output can be defined as, for example, an initial value set at the time of shipment or mounting of the wheel information transmission device.

  As a result, the wheel information transmission device provided on the wheel which is one of the double tires has a transmission output smaller than a predetermined reference output, so that the power consumption is reduced and the wheel information transmission device and the battery driving the wheel information transmission device are reduced. The replacement frequency is reduced. Further, the signal transmitted from the wheel information transmitting device provided on the wheel which is one of the double tires is relayed to the wheel information transmitting device provided on the wheel which is the other of the double tires to the wheel information processing device. Since it can transmit, even if it is the signal output from the wheel information transmission apparatus with which any wheel of the double tire was equipped, it can reach | attain a wheel information processing apparatus.

  Another aspect of the present invention is a wheel information transmitting device. This device is a wheel information transmitting device capable of transmitting wheel information related to a wheel, and includes a detection unit that detects the wheel information, identification information for identifying its own wheel from other wheels, and the wheel information. A wheel-side transmitter that transmits a first wheel signal including the wheel-side receiver that receives a second wheel signal including other identification information and other wheel information transmitted from another wheel information transmitter. And a wheel-side control unit that can determine whether the own wheel is one of the double tires or the other. When the wheel-side control unit determines that its own wheel is one of the double tires, the wheel-side transmission unit causes the first wheel signal to reach the wheel-side receiving unit provided on the other of the double tires. When a transition is made to a power saving transmission mode in which the transmission output is smaller than a predetermined reference output and it is determined that the own wheel is the other of the double tires, it is transmitted from another wheel information transmission device provided on one wheel of the double tire. The operation proceeds to a relay signal transmission mode in which at least a part of the second wheel signal received by the wheel side receiving unit is transmitted.

  According to this aspect, when the wheel-side control unit determines that its own wheel is one of the double tires, the wheel-side transmission is performed so that the first wheel signal reaches the wheel-side receiving unit included in the other of the double tires. The transmission output in the unit can be made smaller than a predetermined reference output. In addition, when the wheel side control unit determines that its own wheel is the other of the double tires, the wheel side control unit transmits the second wheel information transmitted from the other wheel information transmitting device included in one wheel of the double tire and received by the wheel side receiving unit. At least part of the wheel signal of the vehicle can be transmitted.

  As a result, the wheel information transmission device provided on the wheel which is one of the double tires has a transmission output smaller than a predetermined reference output, so that the power consumption is reduced and the wheel information transmission device and the battery driving the wheel information transmission device are reduced. The replacement frequency is reduced. Further, the signal transmitted from the wheel information transmitting device provided on the wheel which is one of the double tires is relayed to the wheel information transmitting device provided on the wheel which is the other of the double tires to the wheel information processing device. Since it can transmit, even if it is the signal output from the wheel information transmitter provided in any wheel of a double tire, it can reach the vehicle body side.

  The wheel side transmission unit may transmit the second wheel signal together with the first wheel signal to the wheel information processing apparatus when it is determined that its own wheel is the other of the double tires. Thereby, the wheel information of both wheels of the double tire can be efficiently transmitted to the wheel information processing device at a time.

  The wheel-side control unit may compare the intensity of the signal received by the wheel-side receiving unit with a predetermined threshold value and determine whether or not the own wheel is a double tire.

  Usually, a plurality of wheels constituting a double tire are arranged close to each other. Therefore, in the wheel information transmitting device attached to one wheel of the double tire, the strength of the signal transmitted from the other wheel information transmitting device attached to the other wheel of the double tire is the vehicle body side where the wheel is attached. It is larger than the intensity of the signal transmitted from the wheel information processing apparatus that receives and processes the wheel information provided in the. Therefore, the strength of the signal received by the wheel side receiving unit can be compared with a predetermined threshold value to determine whether or not the own wheel is a double tire. Thereby, even if the information on whether or not it is a double tire is not registered in advance in the wheel information transmitting device provided in each wheel, the wheel information transmitting device itself determines whether or not it is a double tire. It can be performed.

  The wheel side control unit compares the identification information of the own wheel with other identification information included in the second wheel signal when the own wheel is one of the double tires, It may be determined whether the tire is one or the other.

  Usually, each wheel information transmission device has unique identification information registered therein. Therefore, this identification information can be compared with other identification information included in the second wheel signal to determine whether the wheel is one of the double tires or the other according to a predetermined procedure. For example, when the identification information is a number, it is determined that the wheel provided with the wheel information transmission device with the large identification information number is the other of the double tires, and the wheel information transmission device with the small identification information number is provided. It may be determined that the existing wheel is one of the double tires. Alternatively, it is determined that the wheel provided with the wheel information transmission device having a small identification information number is the other of the double tires, and the wheel provided with the wheel information transmission device having a large identification information number is one of the double tires. May be determined.

  The wheel-side control unit, when the own wheel is one of the double tires, when the own wheel is closer to the wheel information processing device than the own wheel and other wheels constituting the double tire, It may be determined that it is the other of the tires, and when the own wheel is farther from the wheel information processing device than the other wheels, it may be determined that the own wheel is one of the double tires.

  As a result, the wheel side control unit reduces the transmission output of the wheel information transmission device when in the relay signal transmission mode, as compared with the case where the wheels constituting the double tire are located far from the wheel information processing device. Can be set. Therefore, the amount of power consumption is further reduced, and the replacement frequency of the wheel information transmission device and the battery that drives it is reduced.

  The wheel-side control unit is configured such that when the own wheel is one of double tires, the wheel side control unit is self when the own wheel is located on the outer side in the vehicle width direction of the vehicle body with respect to the own wheel and the other wheels constituting the double tire. The wheel may be determined as one of the double tires, and when the own wheel is located on the inner side in the vehicle width direction of the vehicle body than the other wheels, the own wheel may be determined as the other of the double tires. .

  Thereby, since the wheel information transmission device is shifted to the power saving transmission mode when the own wheel constituting the double tire is located outside the vehicle width direction of the vehicle body, the wheel information transmission device includes the same wheel information transmission device. Even when other vehicles stop adjacent to each other, erroneous detection of signals transmitted from each other can be suppressed.

  The wheel side control unit may switch between the power saving transmission mode and the relay signal transmission mode at a predetermined timing.

  When the wheel information transmission device provided in one wheel constituting the double tire has shifted to the power saving transmission mode and the wheel information transmission device provided in the other wheel has shifted to the relay signal transmission mode, the power consumption of both Since the amount is different, the battery life of the wheel information transmission device that has shifted to the relay signal transmission mode will come first. At this time, although the battery life of the wheel information transmission device that has shifted to the power saving transmission mode has not reached its life, the wheels constituting the double tire are removed together from the viewpoint of workability and structure. There are many cases. For this reason, the burden of the operator's replacement work becomes heavy. Also, after replacing the battery of the wheel information transmission device that has shifted to the relay signal transmission mode, if the battery of the wheel information transmission device that has shifted to the power saving transmission mode has reached the end of its life, remove both wheels again and work. Must be done.

  Therefore, the wheel information transmission device provided in each wheel constituting the double tire can average the power consumption by alternately switching between the power saving transmission mode and the relay signal transmission mode at a predetermined timing. As a result, the replacement frequency of the wheel information transmitting device and the battery that drives the same is reduced, so the replacement frequency is reduced.

  When the wheel side control unit has shifted to the relay signal transmission mode, the wheel side control unit compares the wheel information of its own wheel with other wheel information included in the second wheel signal, and the state of the wheel is It is good not to transmit the wheel information of the wheel judged to be relatively good.

  Here, that the state of the wheels is good means that there is little influence on the running of the vehicle, for example, that the air pressure is in an appropriate range. In other words, when the state of the wheel is not good, for example, it can be said that the state of high risk that the air pressure is higher or lower than the appropriate range. In the above-described wheel state monitoring system, the wheel information and the identification information obtained from the respective wheel information transmission devices included in the wheels constituting the double tire are transmitted to the wheel information processing device. However, if the wheel information processing apparatus estimates the state of the wheel based on the wheel information of one of the wheels constituting the double tire that is determined to be relatively unfavorable, the other wheel is at least one of the wheels. It is considered that the condition is better than that of the wheel and the influence on running is small. Therefore, the wheel information transmission device that has shifted to the relay signal transmission mode does not necessarily need to transmit the wheel information of the wheel that is determined to be relatively good, and does not transmit the wheel information. The amount of signal data can be reduced. As a result, it is possible to reduce the amount of power consumption in the wheel information transmission device and also reduce the signal processing load in the wheel information processing device.

  When the wheel side control unit determines that the other wheel information transmitting device provided in the other wheel constituting the self tire and the double tire has failed, when the transition to the power saving transmission mode is made, the wheel side The transmission output in the transmission unit may be changed to a predetermined reference output.

  If the wheel information transmission device that has shifted to the relay signal transmission mode fails, wheel information of both wheels constituting the double tire cannot be transmitted to the wheel information processing device. Therefore, the wheel information of at least one of the wheels constituting the double tire is changed to the wheel information processing device by changing the transmission output in the wheel information transmission device that has been shifted to the power saving transmission mode until then to a predetermined reference output. Can be sent to. As a result, a higher level of failsafe can be achieved.

  When the wheel side control unit does not receive a signal transmitted from the other wheel information transmitting device included in the other wheel constituting the own wheel and the double tire in the wheel side receiving unit for a predetermined time or more, the other wheel information It may be determined that the transmission device has failed, and a signal indicating that another wheel information transmission device has failed may be transmitted to the wheel information processing device together with the first wheel signal.

  Thereby, the wheel information processing device can easily detect that another wheel information transmitting device included in the other wheel constituting the self tire and the double tire is out of order. Further, since the failure of the other wheel information transmitting device is determined by the wheel information transmitting device itself, the load of signal processing in the wheel information processing device can be reduced.

  ADVANTAGE OF THE INVENTION According to this invention, the power consumption of the battery which drives the apparatus which transmits the wheel information relevant to wheels, such as a tire's air pressure and temperature, can be reduced.

  The best mode for carrying out the present invention will be described below in detail with reference to the drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and repeated descriptions are omitted as appropriate.

(First embodiment)
FIG. 1 is a schematic configuration diagram illustrating a vehicle including a wheel information transmission device and a wheel information processing device according to the first embodiment. The vehicle 10 shown in the figure has a so-called double tire structure in which a plurality of wheels are provided in parallel on the left and right of the rear wheel axle. The vehicle 10 includes two wheels 14FR and 14FL provided on the front wheel shaft of the vehicle body 12, and four wheels 14RRin, 14RRout, 14RLin and 14RLout provided on the rear wheel shaft (hereinafter, the wheels 14FR to 14RLout are appropriately set). And a steering device (not shown) that steers the wheels 14FR and 14FL, which are the steering wheels, and a travel drive source (not shown) that drives the driving wheels of these wheels 14. Each wheel 14 includes a wheel and a tire.

  Each of the above-described wheels 14 functions as a tire pressure adjusting valve and as a tire pressure monitoring system (Tire Pressure Monitoring System) for monitoring tire pressure, TPMS valves 20FR, 20FL, 20RRin, 20RRout, 20RLin, 20RLout ( In the following description, TPMS valves 20FR to 20RLout are collectively referred to as “TPMS valve 20” as appropriate.

  Moreover, each wheel 14 (14FR-14RLout) which concerns on this Embodiment outputs the acceleration detection signal according to the acceleration generate | occur | produced with rotation of a wheel as wheel 40 (40FR-40RLout) and wheel information, and a wheel. The acceleration sensor 42 (42FR to 42RLout) is provided on the wheel so that the sign of the acceleration detection signal differs depending on the rotation direction of the wheel. In addition, the direction of each wheel 40 at the time of attaching to a vehicle body changes with wheels. In the vehicle 10 shown in FIG. 1, the direction of the wheel 40 at the wheels 14FR, 14RRin, and 14RLout is opposite to the direction of the wheel 40 at the wheels 14FL, 14RRout, and 14RLin. Therefore, even when the vehicle 10 goes straight and the rotational speeds of the wheels 14 are the same, the sign of the acceleration detection signal output from the acceleration sensors 42FR, 42RRin, 42RLout and the acceleration detection signal output from the acceleration sensors 42FL, 42RRout, 42RLin. The sign is reversed.

  FIG. 2 is a cross-sectional view showing a main part of the wheel 14 provided with the TPMS valve 20. The TPMS valve 20 is attached to a mounting hole 40b provided in the wheel rim 40a of the wheel 40 via a grommet, a washer, a bolt, and the like made of elastic rubber. The valve cap 20a of the TPMS valve 20 protrudes to the outside of the wheel rim 40a. If this valve cap 20a is removed and a hose of an air supply device is connected to a valve port (not shown), air is introduced into the internal space of the tire 18. Supply becomes possible. Each TPMS valve 20 has a housing 20b.

  FIG. 3 is a block diagram for explaining a TPMS valve included in the vehicle of FIG. As shown in FIG. 3, an air pressure sensor 21, a wheel side communicator 22, a control circuit 23, and a battery 24 are accommodated in the housing 20 b of the TPMS valve 20. Thereby, the TPMS valve 20 functions as a wheel information transmission device that acquires tire pressure as wheel information related to the wheel and can periodically transmit the acquired wheel information.

  The air pressure sensor 21 is, for example, a semiconductor sensor, detects air pressure in the tire internal space as wheel information, and outputs an air pressure detection signal corresponding to the air pressure. The wheel-side communicator 22 can periodically wirelessly transmit a signal indicating the detection value of the air pressure sensor 21 at a predetermined cycle (for example, every 1 minute). The control circuit 23 is mounted on an IC chip or the like, and controls the air pressure sensor 21 and the wheel side communication device 22. A battery 24, which is a storage battery, supplies power to the air pressure sensor 21, the wheel side communication device 22, and the control circuit 23. The TPMS valve 20 may further include a temperature sensor that detects the air temperature in the tire interior space, a longitudinal acceleration sensor, a lateral G sensor, a ground pressure sensor, and the like.

  Further, in the vehicle 10 according to the present embodiment, as the identification information for identifying the own wheel from the other wheels with respect to the storage unit of the wheel side communication device 22 included in the TPMS valve 20 of each wheel 14. Each has a unique ID code. In the present embodiment, for example, an ID code = 1 is assigned to the wheel side communication device 22 of the TPMS valve 20FR attached to the right front wheel 14FR, and the wheel side of the TPMS valve 20FL attached to the left front wheel 14FL is provided. ID code = 2 is assigned to the communicator 22, and ID code = 3 is assigned to the wheel side communicator 22 of the TPMS valve 20RRout attached to the wheel 14RRout on the right rear outer side, and is attached to the wheel 14RRin on the right rear inner side. An ID code = 4 is assigned to the wheel side communication device 22 of the TPMS valve 20RRin, and an ID code = 5 is assigned to the wheel side communication device 22 of the TPMS valve 20RLout attached to the wheel 14RLout on the left rear outer side. An ID code = 6 is assigned to the wheel side communication device 22 of the TPMS valve 20RLin attached to the wheel 14RLin.

  The signal periodically transmitted from each wheel-side communication device 22 includes an ID code indicating the transmission-side wheel-side communication device 22 along with the detection value by the air pressure sensor 21. That is, each wheel side communicator 22 periodically transmits a signal including information detected by the air pressure sensor 21 and its own ID code as information. Each wheel side communicator 22 can also receive a signal including the ID code of the other wheel and the wheel information of the other wheel transmitted from the other TPMS valve 20. The periodic transmission of the signal of the wheel side communicator 22 is started from the stage when the TPMS valve 20 is mounted on the wheel 14 configured by mounting the tire on the wheel and shipped from the factory as an assembly. Yes.

  On the other hand, as shown in FIGS. 1 and 3, the vehicle body 12 of the vehicle 10 has an electronic control unit as processing means for executing various controls using information transmitted from the wheel side communication device 22 of the TPMS valve 20. (Hereinafter referred to as “ECU”) 30 is mounted. The ECU 30 includes a CPU that executes various arithmetic processes, a ROM that stores various control programs, a RAM that is used as a work area for data storage and program execution, an input / output interface, a storage device, and the like. As shown in FIG. 1, the ECU 30 is connected to a vehicle body side communication device 25, a sensor group 26, and an alarm device 27.

  The vehicle body side communication device 25 performs signal transmission / reception with the wheel side communication device 22 included in the TPMS valve 20 of each wheel 14, and receives a signal wirelessly transmitted from the wheel side communication device 22. It gives to ECU30. The sensor group 26 includes, for example, a wheel speed sensor (not shown) that is provided for each wheel 14 and detects the speed of the corresponding wheel 14. The warning device 27 issues a warning to the driver under a predetermined condition under the control of the ECU 30, and includes, for example, a warning display device provided on the instrument panel of the vehicle 10.

  The wheel information processing apparatus according to the present embodiment is mainly configured by the vehicle body side communication device 25, the ECU 30, and the like, and processes wheel information related to the wheels transmitted from the TPMS valve 20. While the vehicle 10 is traveling, the air pressure of the wheel 14 is detected by the air pressure sensor 21 of each TPMS valve 20, and a signal indicating the detected value of the air pressure sensor 21 and its own ID code is sent from each wheel side communication device 22 to the vehicle body. Periodically transmitted to the side communication device 25. When the vehicle body side communication device 25 receives a signal from the wheel side communication device 22, the ECU 30 stores (registers) the ID included in the signal received by the vehicle body side communication device 25 in the storage device. When the ID matches one of the existing IDs, a predetermined process using the received signal is executed, and the state of the wheel 14 is estimated.

  As described above, the wheel state monitoring system according to the present embodiment includes a plurality of TPMS valves 20 capable of transmitting wheel information related to the wheels 14 and a wheel information processing apparatus that receives and processes the wheel information. The state of the wheel can be monitored by transmitting and receiving information to and from each other.

  When the TPMS valve 20 used in such a wheel state monitoring system periodically wirelessly transmits a signal indicating the detected value of the air pressure sensor 21 and its own ID code from the wheel side communication device 22 to the vehicle body side communication device 25. The power of the battery 24 is consumed. Therefore, when a certain period of use of the TPMS valve 20 has passed, in other words, when the number of transmissions reaches a predetermined number, the battery 24 needs to be replaced due to power consumption.

  FIG. 4A is a schematic diagram showing a state of transmission at a normal reference output of the TPMS valve 20 provided on the wheels constituting the double tire. As shown in FIG. 4A, the outputs of the signals transmitted from the TPMS valves 20RRin and 20RRout are the same. In addition, the magnitude of the transmission output is set to such a magnitude that the signal reaches at least the vehicle body side communication device 25.

  However, when the wheel 14RRout is one of the double tires as in the vehicle 10 according to the present embodiment, a signal may be directly transmitted to the ECU 30, but the wheel 14RRin constituting the other of the double tires is provided. It may be transmitted to the ECU 30 via the TPMS valve 20RRin. At this time, the signal transmitted from the TPMS valve 20RRout only needs to reach the wheel-side communication device included in the wheel 14RRin constituting the other of the double tires arranged in parallel in the vicinity of the wheel 14RRout, and does not necessarily reach the ECU 30. No transmission output is required.

  FIG. 4B is a schematic diagram showing a state of transmission in the power saving transmission mode of the TPMS valve 20RRout provided on the wheels constituting the double tire. As shown in FIG. 4 (b), the output of the signal transmitted from the TPMS valve 20RRin is the same as that of FIG. 4 (a), but the output of the signal transmitted from the TPMS valve 20RRout The transmission output in the wheel side communicator 22 is smaller than a predetermined reference output to such an extent that a signal including an ID code for identifying a wheel and a value detected by the air pressure sensor 21 reaches the TPMS valve 20RRin.

  Therefore, the TPMS valve 20RRout according to the present embodiment determines whether the own wheel 14RRout is one of the double tires, the other, or a single tire, and the own wheel is one of the double tires. In the case where it is determined that the signal transmitted from the wheel-side communication device reaches the wheel-side communication device of the TPMS valve 20RRin provided in the other of the double tires, the power output for making the transmission output in the wheel-side communication device smaller than a predetermined reference output Switch to transmission mode. In addition, when it is determined that the wheel 14RRin is the other of the double tires, the TPMS valve 20RRin transmits at least a part of the signal transmitted from the TPMS valve 20RRout that has shifted to the power saving transmission mode and received by the wheel side communication device. The relay signal transmission mode for transmission to the ECU 30 is entered. Here, the predetermined reference output is an initial value set at the time of shipment or mounting of the TPMS valve 20, and is set as a magnitude of an output so that a signal reaches the vehicle body side communication device 25 provided in the ECU 30 with certainty. Has been.

  FIG. 5 is a flowchart for explaining a procedure for determining whether or not the wheel provided with each TPMS valve in FIG. 1 is a double tire.

  In the vehicle 10 according to the present embodiment, whether or not the wheel 14 provided with each TPMS valve 20 is a double tire is determined by, for example, mounting the wheel 14, the ECU 30, etc. on the vehicle body 12. It is executed when the wheels 14 are exchanged or rotated on the subsequent production line of the vehicle 10 or by inspection or maintenance. In this case, when the power of each TPMS valve 20 is not turned on, first, the power of each TPMS valve 20 is turned on by a signal from an external device or manually. Thereafter, the TPMS valve 20 according to the present embodiment periodically transmits a signal indicating the detected value of the air pressure sensor 21 and its own ID code from the vehicle body side communication device 25 periodically (for example, at intervals of 1 minute). .

  Whether the wheel 14 provided with a certain TPMS valve 20 is a double tire is determined for each TPMS valve 20, but for the sake of convenience, the TPMS valve provided in the right rear wheel 14RRin will be described below. 20RRin will be described. The wheel-side communicator 22 included in the TPMS valve 20RRin functioning as a wheel-side receiving unit receives a signal transmitted from a wheel information processing apparatus including the ECU 30 or a signal including another ID code transmitted from another TPMS valve 20. If this is the case (Yes in S10), the intensity Is of the signal is calculated by the wheel side calculation unit of the control circuit 23 (S12).

  The signal strength Is is not uniform, which TPMS valve 20 the signal is transmitted from, or the vehicle body side functioning as a vehicle body side transmitter provided on the vehicle body 12 side where the wheel 14 is mounted. It depends on whether the signal is transmitted from the communication device 25 or not. FIG. 6 is a diagram schematically showing the intensity of the signal received at the TPMS valve 20RRin provided on one wheel of the double tire.

  Usually, a plurality of wheels constituting the double tire, for example, the wheels 14RRin and 14RRout are arranged close to each other. Therefore, as shown in FIG. 6, in the TPMS valve 20RRin provided on one wheel 14RRin of the double tire, the intensity of the signal transmitted from the other TPMS valve 20RRout provided on the other wheel 14RRout of the double tire is The intensity of the signal transmitted from the other TPMS valve 20FR mounted on the wheel 14FR of the single tire and the intensity of the signal transmitted from the vehicle body side communication device 25 provided on the vehicle body 12 side are larger.

  Therefore, the control circuit 23 compares the intensity Is of the signal received by the wheel side communication device 22 with a predetermined threshold Th (S14), for example, when the intensity Is of the received signal is larger than the predetermined threshold Th. (Yes in S14), it is determined that the own wheel is one of the double tires (S16). In the present embodiment, the threshold value Th is set based on the strength of the received signal when transmission / reception is performed between the wheels constituting the double tire.

  On the other hand, when a signal is not received in the wheel side communication device 22 (No in S10), the control circuit 23 determines whether or not the state continues for a predetermined time (S20). Although no signal is received in the wheel side communication device 22, if the predetermined time has not elapsed since the wheel 14 was mounted on the vehicle body 12 and the power source of the TPMS valve 20RRin was activated (No in S20), the process returns to S10. When the wheel-side communication device 22 does not receive an appropriate signal and a predetermined time has elapsed (Yes in S20), it is determined that the TPMS valve 20 is provided on a wheel constituting a single tire (S22).

  Note that the TPMS valve 20RRin does not always receive only the signal transmitted by the nearest TPMS valve 20RRout. For example, it is possible to receive signals from the TPMS valve 20FR and the TPMS valve 20FL which are located away from the TPMS valve 20RRout with respect to the TPMS valve 20RRin, and also from the TPMS valve mounted on the vehicle body side communication device 25 and other vehicles. There is also sex. Therefore, when the intensity Is of the received signal is equal to or less than the threshold Th (No in S14), the process returns to S10.

  As described above, the TPMS valve 20 according to the present embodiment compares the intensity of the signal received by the wheel side communication device 22 with the predetermined threshold value, and determines whether or not its own wheel is a double tire. be able to. Next, a method for determining whether the own wheel is one of the double tires or the other when the own wheel is one of the double tires will be described.

  FIG. 7 illustrates a procedure for determining whether the wheel provided with the TPMS valve in the process of FIG. 5 is one of the double tires, or whether the wheel is one of the double tires. It is a flowchart for.

  The determination as to whether or not the wheel 14 provided with the TPMS valves 20RRin, 20RRout, 20RLin, and 20RLout is a double tire is executed for each TPMS valve 20, but for the sake of convenience, the right rear wheel 14RRin, The TPMS valves 20RRin and 20RRout provided in the 14RRout will be described.

  The control circuit 23 of the TPMS valve 20RRin includes, among the received signals, an ID code (= 4) of its own wheel 14RRin and an ID code (= 3) of another wheel 14RRout constituting the double tire with its own wheel. Compare (S30). In the case of the TPMS valve 20RRin, since the ID code of the own wheel 14RRin is larger than the ID code of the other wheel 14RRout (Yes in S30), the control circuit 23 determines the own wheel 14RRin as the other of the double tires (S32). Then, the relay signal transmission mode is entered (S34).

  On the other hand, the control circuit 23 of the TPMS valve 20RRout compares the ID code (= 3) of the own wheel 14RRout with the ID code (= 4) of the other wheel 14RRin constituting the double tire with the own wheel (S30). ). In the case of the TPMS valve 20RRout, since the ID code of the own wheel 14RRout is smaller than the ID code of the other wheel 14RRin (No in S30), the control circuit 23 determines that the own wheel 14RRout is one of the double tires (S36). Then, it shifts to the power saving transmission mode (S38).

  Thereby, since the transmission output of the TPMS valve 20RRout provided on the wheel 14RRout which is one of the double tires is smaller than a predetermined reference output, the power consumption is reduced, and the TPMS valve 20RRout and the battery 24 for driving the TPMS valve 20RRout The replacement frequency is reduced. Further, at least a part of a signal transmitted from the TPMS valve 20RRout provided on the wheel 14RRout which is one of the double tires is relayed to the ECU 30 via the TPMS valve 20RRin provided on the wheel 14RRin which is the other of the double tires. Sent to. Therefore, the signals output from the TPMS valves 20RRin and 20RRout provided on any of the wheels of the double tire are both transmitted to the ECU 30.

  When the wheel side communicator 22 determines that its own wheel 14RRin is the other of the double tires, the wheel side communicator 22 constitutes a double tire together with a signal including the ID code of its own wheel 14RRin and a detected value by the air pressure sensor. A signal including the ID code transmitted from the wheel 14RRout and the detected value by the air pressure sensor may be transmitted to the ECU 30. Thereby, the wheel information of both wheels of the double tire can be efficiently transmitted to the ECU 30 at a time.

  The above-described effects can also be achieved by the wheel state monitoring system using the TPMS valve 20 according to the present embodiment. In the wheel state monitoring system, the state of the wheel is obtained by transmitting and receiving information between the plurality of TPMS valves 20 described above and the wheel information processing apparatus including the vehicle body side communication device 25 that receives wheel information and the ECU 30 that processes wheel information. To monitor. The TPMS valve 20 transmits a signal including an air pressure sensor 21 that detects air pressure as wheel information, an ID code for identifying its own wheel from other wheels, and information on the air pressure. The wheel side communicator 22 that receives a signal transmitted from the TPMS valve 20 and a control circuit 23 that determines whether or not its own wheel is a double tire are provided.

  The wheel information processing apparatus receives the signal including the ID code and the air pressure information of the wheel transmitted from the TPMS valve 20, and the TPMS valve 20 based on the received ID code and the air pressure information. ECU30 which estimates the state of the wheel 14 in which this is provided. The wheel information processing device issues a warning to the driver and the operator via the alarm device 27 when the tire puncture or the air pressure is detected to be extremely low or high from the air pressure information received by the ECU 30.

(Second Embodiment)
The wheel state monitoring system according to the present embodiment shifts the TPMS valve provided on the wheel close to the wheel information processing device among the pair of wheels constituting the double tire to the relay signal transmission mode, and from the wheel information processing device. The TPMS valve provided on the far wheel is shifted to the power saving transmission mode. In the following, a description overlapping with the first embodiment will be omitted as appropriate. In the following description, the wheels 14RRin and 14RRout constituting the double tire will be described as an example, but the same processing is performed for other double tires.

  FIG. 8 is a flowchart for explaining a procedure for registering whether or not the wheel provided with each TPMS valve 20 in the wheel state monitoring system according to the second embodiment constitutes a double tire.

  In the vehicle 10 according to the present embodiment, the registration of whether or not the wheel provided with each TPMS valve 20 constitutes a double tire is performed, for example, after the wheel 14, the ECU 30, etc. are mounted on the vehicle body 12. This is executed when the wheel 14 is exchanged or rotated on the production line of the vehicle 10 or by inspection or maintenance. In this case, when the power of each TPMS valve 20 is not turned on, first, the power of each TPMS valve 20 is turned on by a signal from an external device or manually.

  Thereafter, as shown in FIG. 8, the wheel state monitoring system is set to the double tire registration mode (S40). The vehicle body side communication device 25 transmits a request signal for requesting transmission of its own wheel ID code and wheel information to each TPMS valve 20 (S42). Each TPMS valve 20 that has received the request signal transmits a signal including its own ID code and wheel information from the wheel side communication device 22. For example, when a signal including another ID code transmitted from another TPMS valve 20RRout is received by the wheel-side communication device 22 provided in the TPMS valve 20RRin (Yes in S44), the intensity Is of the signal is determined by the control circuit 23. Is calculated by the wheel side calculation unit (S46).

  The control circuit 23 compares the intensity Is of the signal received by the wheel side communication device 22 with a predetermined threshold Th (S48). For example, when the intensity Is of the received signal is larger than the predetermined threshold Th (S48). Yes), it is determined that the own wheel is one of the double tires (S50). In the present embodiment, the threshold value Th is set based on the strength of the received signal when transmission / reception is performed between the wheels constituting the double tire. The TPMS valve 20 has its own wheel ID code from the wheel side communicator 22, the own wheel received in S44, the ID code of the other wheel constituting the double tire, and the own wheel of the double tire. Then, a registration signal including a flag 1 indicating that it is a negative is transmitted (S52).

  FIG. 9 is a diagram illustrating a configuration of transmission data transmitted from the wheel side communication device 22 of the TPMS valve 20. The transmission data includes a synchronization pattern, an ID code of the own wheel, an ID code of another wheel, a relative position code indicating that the own wheel and the other wheel constitute a double tire, and the like. The ECU 30 receives and registers the registration signal transmitted from each TPMS valve 20 by the vehicle body side communication device 25. Thereby, ECU30 registers the information which shows that the wheels which have two ID codes contained in a registration signal are double tires in a memory | storage part (S54).

  On the other hand, when a signal is not received in the wheel side communication device 22 (No in S44), the control circuit 23 determines whether or not the state continues for a predetermined time (S56). No signal is received in the wheel side communicator 22, but a predetermined time has not elapsed since the wheel 14 was mounted on the vehicle body 12 and the power source of the TPMS valve 20 was activated, or after shifting to the double tire registration mode. If (No in S56), the process returns to S44. If the wheel-side communication device 22 does not receive an appropriate signal and a predetermined time has elapsed (Yes in S56), the control circuit 23 determines that its own wheel is a wheel constituting a single tire (S58). And the TPMS valve | bulb 20 transmits the registration signal containing the flag 0 which shows that the own wheel ID code and its own wheel are single tires from the wheel side communication apparatus 22 (S60). The ECU 30 also registers this registration signal in the storage unit (S56).

  Note that the TPMS valve 20RRin does not always receive only the signal transmitted by the nearest TPMS valve 20RRout. For example, it is possible to receive signals from the TPMS valve 20FR and the TPMS valve 20FL which are located away from the TPMS valve 20RRout with respect to the TPMS valve 20RRin, and also from the TPMS valve mounted on the vehicle body side communication device 25 and other vehicles. There is also sex. Therefore, when the intensity Is of the received signal is equal to or less than the threshold Th (No in S48), the process returns to S44.

  FIG. 10 illustrates a procedure for determining whether a wheel provided with a TPMS valve in the process of FIG. 8 is one of double tires and whether it is one of the double tires or the other. It is a flowchart for.

When the ECU 30 receives, for example, a signal transmitted from the TPMS valve 20RRin including the flag 1 indicating a double tire as the registration signal transmitted from each TPMS valve 20 described above (Yes in S62), the intensity I _{s1 of the} signal Is calculated (S64). On the other hand, when the ECU 30 receives a signal not including the flag 1 indicating a double tire (No in S62), the ECU 30 returns to S62.

When the signal received in S62 is a signal transmitted from the TPMS valve 20RRin, the TPMS valve 20RRout included in the wheel 14RRin and the wheel 14RRout constituting the double tire is paired with the TPMS valve 20RRin. Therefore, (Yes in S66) when receiving the signal from the TPMS valve 20RRout, it calculates the intensity _{I s2} of the signal (S68). On the other hand, when the ECU 30 receives a signal from other than the TPMS valve 20RRout (No in S66), the ECU 30 returns to S66.

ECU30 compares the intensity _{I s1} and intensity _{I s2} (S70), TPMS valve 20RRin, wheels are provided with 20RRout 14RRin, 14RRout to determine whether one or the other of the twin wheels (S72). In the vehicle 10 according to the present embodiment, since the TPMS valve 20RRin is closer to the vehicle body side communication device 25 than the TPMS valve 20RRout, the intensity I _s1 > the intensity I _s2 is satisfied. Accordingly, the ECU 30 determines that the wheel 14RRin is the other of the double tires and the wheel 14RRout is one of the double tires, transmits a signal instructing the transition to the relay signal transmission mode to the TPMS valve 20RRin, and transmits the signal to the TPMS valve 20RRout. On the other hand, a signal for instructing the shift to the power saving transmission mode is transmitted (S74).

  Thereby, since the ECU 30 receives a signal from the TPMS valve 20 closer to the vehicle body side communication device 25, the reception sensitivity is improved. Further, the TPMS valve 20RRin disposed at a position relatively close to the vehicle body side communication device 25 can communicate even if the signal transmission intensity is lowered. Therefore, the ECU 30 may transmit a signal that instructs the TPMS valve 20RRin to reduce the transmission output to the extent that communication with the vehicle body side communication device 25 is possible. As a result, the TPMS valve 20RRin that has shifted to the relay signal transmission mode can reduce the transmission output as compared with the case where its own wheel constituting the double tire is located far from the wheel information processing device. Therefore, the amount of power consumption is further reduced, and the replacement frequency of the wheel information transmission device and the battery that drives it is reduced.

(Third embodiment)
The wheel state monitoring system according to the present embodiment shifts the TPMS valve provided on the wheel located on the outer side in the vehicle width direction of the vehicle body among the pair of wheels constituting the double tire to the power saving transmission mode, The TPMS valve provided in the wheel located inside the vehicle width direction of the vehicle body is shifted to the relay signal transmission mode. In the following description, matters overlapping with the above-described embodiments are omitted as appropriate. In the following description, the vehicle 10 shown in FIG. 1 will be described as an example.

  In the present embodiment, first, in the TPMS valve 20, position information indicating whether or not each wheel is one of double tires is calculated by the processing described in the first embodiment. For example, the TPMS valve 20RRin provided in the wheel 14RRin compares the intensity of the received signal with a predetermined threshold by the control circuit 23 and transmits the signal to the wheel 14 provided with the TPMS valve 20 and its own wheel. Position information indicating a relative position with respect to 14RRin is calculated. In the present embodiment, the threshold Th0 is set based on the strength of the received signal when transmission / reception is performed between the wheels constituting the double tire, the relative position of which is closest in the vehicle (for example, six-wheeled vehicle) constituting the double tire. Has been.

  When the intensity Is of the signal received by the TPMS valve 20RRin is larger than the threshold Th0, the ID code included in the received signal is stored in the storage unit provided in the wheel side communication device 22 or the control circuit 23. In the present embodiment, when the signal transmitted from the TPMS valve 20RRout is received by the TPMS valve 20RRin, the signal strength Is is larger than the threshold value Th0, so that 3 is stored as the ID code in the storage unit.

  In the control circuit 23, the TPMS valve 20RRin is a position information indicating a relative position with respect to the TPMS valve 20RRout, and a relative position code, for example, 1 indicating that the TPMS valve 20RRin is one of the double tires together with the TPMS valve 20RRout. Calculate and store the relative position code. As a result, the relative position code 1 is stored as position information indicating that the wheel 14RRin, 14RRout, 14RLin, 14RLout is mounted on one of the positions of the double tire in the TPMS valves 20RRin, 20RRout, 20RLin, 20RLout. Will be. On the other hand, the relative position code 0 is stored in the TPMS valves 20FR, FL included in the wheels 14FR, 14FL as position information indicating that the wheels 14FR, 14FL are mounted at positions where ordinary single tires are mounted.

  And the wheel side communication apparatus 22 of each TPMS valve | bulb 20 transmits a relative position code with the ID code of a self-wheel at a predetermined timing. The wheel side communicator 22 may transmit ID codes of other wheels together with the relative position code. Accordingly, it can be determined that the wheel corresponding to the ID code of the own wheel and the wheel corresponding to the ID code of the other wheel constitute a pair of double tires.

  Moreover, each wheel 14 (14FR-14RLout) which concerns on this Embodiment outputs the acceleration detection signal according to the acceleration which generate | occur | produces with rotation of a wheel 40 as wheel information (40FR-40RLout) as mentioned above. In addition, an acceleration sensor 42 (42FR to 42RLout) is provided on the wheel so that the sign of the acceleration detection signal differs depending on the rotation direction of the wheel.

  Therefore, in the vehicle 10 according to the present embodiment, the wheel side communication device 22 of each TPMS valve 20 transmits an acceleration detection signal together with its own ID code. As a result, the wheel information processing apparatus that has received this signal determines the sign of the acceleration detection signal and estimates the mounting position of the wheel.

  The wheel information processing apparatus executes the wheel position specifying mode shown below with the position information indicating whether or not each wheel 14 is a double tire, thereby identifying each wheel in a vehicle equipped with a double tire. The information and the mounting position of the wheel on the vehicle body can be easily specified with a simple configuration.

  FIG. 11 is a flowchart for explaining a procedure for registering information on the mounting position of each wheel provided with each TPMS valve of FIG. 1 in the wheel information processing apparatus together with the identification information of the wheel. In the vehicle 10 according to the present embodiment, registration of information on the mounting position of the wheel 14 provided with each TPMS valve 20 on the vehicle body to the ECU 30 is implemented by the wheel 14, the ECU 30, etc. on the vehicle body 12. It is executed when the vehicle 10 travels after the vehicle has been moved, or during travel after the wheels 14 have been replaced or rotated by inspection or maintenance.

  First, as shown in FIG. 11, the ECU 30 is set to the wheel position specifying mode (S80). Then, the ECU 30 determines whether or not the signal transmitted from the wheel side communication device 22 of each TPMS valve 20 is received by the vehicle body side communication device 25 (S82). When it is determined that the vehicle body side communication device 25 has not received a signal from any of the wheel side communication devices 22 (No in S82), the ECU 30 has passed a predetermined time after setting the wheel position specifying mode. It is determined whether or not there is (S84). If the ECU 30 determines that the predetermined time has not elapsed (No in S84), the process of S82 is executed again.

  When it is determined that the vehicle body side communication device 25 has received a signal from any one of the wheel side communication devices 22 (Yes in S82), the ECU 30 determines the ID code and the relative position included in the signal received by the vehicle body side communication device 25. The mounting position of the wheel on the vehicle body is estimated from the code, the acceleration detection signal, and the like. Specifically, the ECU 30 first determines whether or not the relative position code is 1 (S86). When the ECU 30 determines that the relative position code is not 1 (No in S86), the ECU 30 estimates that the wheel corresponding to the ID code included in this signal is the right front wheel 14FR or the left front wheel 14FL. Can do.

  Further, the ECU 30 determines whether or not the acceleration is positive from the acceleration detection signal received by the vehicle body side communication device 25 (S88). In the present embodiment, when the vehicle 40 is moving forward when the direction of the wheel 40 with respect to the vehicle 10 is the wheels 14FL, 14RRout, 14RLin, the sign of the signal output from each acceleration sensor 42 is Become positive. Therefore, when it is determined that the acceleration detection signal is positive (Yes in S88), the ECU 30 identifies the wheel corresponding to the ID code as the wheel 14FL that is the left front wheel, and registers the ID code as the left front wheel (S90). On the other hand, if the ECU 30 determines that the acceleration detection signal is not positive (No in S88), the wheel corresponding to the ID code is identified as the right front wheel 14FR, and the ID code is registered as the right front wheel (S92). . Thereafter, the ECU 30 determines whether or not the ID code registration for all the wheels has been completed (S94). If the registration for all the wheels has not been completed (No in S94), the process of S82 is executed again. On the other hand, when registration with respect to all the wheels is completed (Yes in S94), the wheel position specifying mode is ended (S96).

  Next, when the ECU 30 determines that the relative position code is 1 (Yes in S86), the wheel corresponding to the ID code included in this signal is one of the wheels 14RRin, 14RRout, 14RLin, 14RLout constituting the double tire. Presume that there is. However, it is not possible to determine which ID code of these wheels only by determining whether the acceleration detection signal is positive or negative thereafter.

  Therefore, the wheel information processing apparatus according to the present embodiment outputs a wheel speed detection signal corresponding to the rotational speed of each wheel 14 mounted on the vehicle body 12 as the sensor group 26 in addition to the ECU 30 and the vehicle body side communication device 25. A wheel speed sensor is further provided. Thus, the steering direction of the vehicle 10 can be determined from the wheel speed detection signal corresponding to the rotational speed of each wheel 14. More specifically, when the steering direction of the vehicle 10 is changed from the straight traveling direction of the vehicle 10, the wheel 14RLin, 14RLout serving as the left rear wheel and the 14RRin, 14RRout serving as the right rear wheel rotate due to a difference in the rotation radius. Since there is a difference in speed, the steering direction of the vehicle can be determined by comparing the wheel speed of the left rear wheel with the wheel speed of the right rear wheel. Further, when a difference occurs in the rotation speed of each wheel, a difference also occurs in the acceleration in each wheel. For example, when the vehicle is steered in the right direction, the strength of the acceleration detection signal of the wheels 14RLin and 14RLout mounted on the left side of the vehicle body is the intensity of the acceleration detection signal of the wheels 14RRin and 14RRout mounted on the right side of the vehicle body. Its absolute value is larger than strength.

  FIG. 12 is a diagram schematically showing the intensity of the acceleration detection signal corresponding to the acceleration generated at each rear wheel when turning right at a constant steering angle. In the present embodiment, as described above, the wheels 14RRout and 14RLin have positive acceleration detection signals when the vehicle is moving forward among the rear wheels. Similarly, of each rear wheel, the wheels 14RRin and 14RLout have negative acceleration detection signals when the vehicle is moving forward. Therefore, the acceleration detection signal P1 is a signal transmitted from the wheel 14RLin, the acceleration detection signal P2 is a signal transmitted from the wheel 14RRout, the acceleration detection signal P3 is a signal transmitted from the wheel 14RRin, and the acceleration detection signal P4 is transmitted from the wheel 14RLout. Signal.

  Therefore, the ECU 30 detects detection signals from a left rear wheel speed sensor and a right rear wheel speed sensor (not shown) included in the sensor group 26 at the timing when the acceleration of each wheel is detected, and the left signal is detected based on the detection signal. It is determined whether or not the rear wheel speed is faster than the right rear wheel speed (S98). When it is determined that the left rear wheel speed is not faster than the right rear wheel speed (No in S98), the ECU 30 determines that each rear wheel cannot be specified at this time, and executes the process of S82 again. On the other hand, if the ECU 30 determines that the left rear wheel speed is faster than the right rear wheel speed (Yes in S98), the ECU 30 identifies each rear wheel by the processing after S100.

  The ECU 30 determines whether the acceleration is positive from the acceleration detection signal received by the vehicle body side communication device 25 (S100). When it is determined that the acceleration detection signal is positive (Yes in S100), the ECU 30 may estimate that the wheel corresponding to the ID code is either the left rear inner wheel 14RLin or the right rear outer wheel 14RRout. it can. Therefore, the ECU 30 compares the intensity of the acceleration detection signal with a predetermined threshold C1 (S102). When it is determined that the intensity of the acceleration detection signal is greater than the threshold value C1 (Yes in S102), the ECU 30 identifies the wheel corresponding to the ID code as the wheel 14RLin that is the left rear inner ring, and the ID code is identified as the left rear inner ring. (S104). On the other hand, when it is determined that the intensity of the acceleration detection signal is not greater than the threshold value C1 (No in S102), the ECU 30 identifies the wheel corresponding to the ID code as the wheel 14RRout that is the right rear outer wheel, and the ID code is determined. The right rear outer ring is registered (S106).

  When the ECU 30 determines that the acceleration detection signal is not positive (No in S100), the wheel corresponding to the ID code is estimated to be either the left rear outer wheel 14RLout or the right rear inner wheel 14RRin. can do. Therefore, the ECU 30 compares the intensity of the acceleration detection signal with a predetermined threshold C2 (S108). When it is determined that the intensity of the acceleration detection signal is smaller than the threshold value C2 (Yes in S108), the ECU 30 identifies the wheel corresponding to the ID code as the wheel 14RLout that is the left rear outer wheel, and the ID code is identified as the left rear outer wheel. (S110). On the other hand, when it is determined that the intensity of the acceleration detection signal is not smaller than the threshold value C2 (No in S108), the ECU 30 identifies the wheel corresponding to the ID code as the wheel 14RRin which is the right rear inner wheel, and the ID code is determined. The right rear inner ring is registered (S112). Thereafter, the ECU 30 determines whether or not the ID code registration for all the wheels has been completed (S94). If the registration for all the wheels has not been completed (No in S94), the process of S82 is executed again. On the other hand, when registration with respect to all the wheels is completed (Yes in S94), the wheel position specifying mode is ended (S96).

  If there is no signal reception and a predetermined time has elapsed (No in S82, Yes in S84), there is a possibility that any TPMS valve 20 or wheel information processing device has some trouble, so all wheels are registered. Even if not completed, the wheel position specifying mode is forcibly ended (S96).

  The ECU 30 in which the position of each wheel is registered by the above-described processing includes information on whether the vehicle body 12 is positioned on the outer side in the vehicle width direction with respect to the TPMS valve 20 provided in each wheel 14 constituting the double tire. Send a signal. In the present embodiment, the ECU 30 transmits a position signal indicating that the vehicle body 12 is positioned outside the vehicle body 12 in the vehicle width direction to the TPMS valves 20RRout and 20RLout, and the vehicle body of the vehicle body is transmitted to the TPMS valves 20RRin and 20RLout. A position signal indicating that the vehicle is located inside in the vehicle width direction is transmitted.

  The control circuit 23 provided in the TPMS valve 20 determines that its own wheel is one of the double tires when the position signal located outside the vehicle width direction of the vehicle body is received by the wheel side communication device 22, and transmits power saving. When the mode signal is received and a position signal located on the inner side in the vehicle width direction of the vehicle body is received by the wheel side communication device 22, it is determined that the own wheel is the other of the double tires, and the mode is shifted to the relay signal transmission mode. As a result, the TPMS valve 20 provided in each wheel 14 shifts to the power saving transmission mode when its own wheels constituting the double tire are located outside the vehicle width direction of the vehicle body. Even when another vehicle equipped with the vehicle stops adjacently, erroneous detection of signals transmitted from each other can be suppressed.

(Fourth embodiment)
In the wheel state monitoring system according to the present embodiment, the TPMS valve of each wheel constituting the double tire is changed from the power saving transmission mode to the relay signal transmission mode or from the relay signal transmission mode to the power saving transmission mode at a predetermined timing. Can be switched.

  Specifically, for example, the transmission modes of the TPMS valves 20RRin and 20RRout included in the wheels 14RRin and 14RRout constituting the double tire may be switched at the timing when the signals are received N times. Further, the ECU 30 of the wheel information processing apparatus communicates the trigger signal for switching the transmission mode to each of the TPMS valves 20RRin and 20RRout provided on the wheels 14RRin and 14RRout constituting the double tire at a predetermined timing. You may control to transmit from the machine 25.

  As a result, the TPMS valves 20RRin and 20RRout can alternately switch between the power saving transmission mode and the relay signal transmission mode at a predetermined timing, and can average each other's power consumption. As a result, since the replacement times of the TPMS valves 20 of the double tires and the batteries that drive the same are aligned, the frequency of the replacement work is reduced.

(Fifth embodiment)
In the above-described embodiment, the TPMS valve 20 that has shifted to the relay signal transmission mode transmits the ID code transmitted from the other wheels constituting the double tire together with the signal including the ID code of the own wheel and the detected value by the air pressure sensor. A signal including a code and a value detected by an air pressure sensor is transmitted.

  However, in such a case, the TPMS valve 20 that has shifted to the relay signal transmission mode has a larger amount of signal data to be transmitted than in the case of transmitting the wheel information of its own wheels. The amount of power required increases. Therefore, the TPMS valve 20 that has shifted to the relay signal transmission mode transmits wheel information of wheels having relatively large tire pressure drops among the wheels constituting the double tire to the ECU 30, and the tire pressure drop is relatively low. If the wheel information of a small wheel is not transmitted to the ECU, the data amount of the signal to be transmitted can be reduced and the amount of power required for transmission can be suppressed. This also reduces the signal processing load on the ECU 30.

  In this way, the TPMS valve 20 that has shifted to the relay signal transmission mode has a relatively low decrease in tire air pressure even if it does not transmit to the ECU the wheel information of wheels with relatively small decrease in tire air pressure. Since the wheel information of the large wheel is transmitted to the ECU 30, the ECU 30 only needs to determine the state of the wheel from the wheel information of the wheel having a relatively large decrease in tire air pressure. Since the other wheel is in a better state than at least one wheel and is considered to have less influence on the running, there is no problem even with such processing.

  Here, that the state of the wheels is good means that there is little influence on the running of the vehicle, for example, that the air pressure and temperature are within an appropriate range. In other words, when the state of the wheel is not good, for example, it can be said that there is a high risk of the air pressure or temperature being higher or lower than the appropriate range. In addition, instead of comparing the degree of decrease in air pressure as in this embodiment, the displacement information from a predetermined appropriate pressure or temperature is compared, wheel information for a wheel with a large displacement is transmitted, and the displacement is The wheel information of small wheels may not be transmitted.

  FIG. 13 is a flowchart for explaining a procedure for determining information to be transmitted from the TPMS valve according to the fifth embodiment. Hereinafter, signal processing in the TPMS valve 20RRin that has shifted to the relay signal transmission mode by the processing described in FIG. 7 according to the first embodiment will be described as an example.

  The TPMS valve 20RRin acquires information on the air pressure P1 of its own wheel 14RRin by the air pressure sensor 21 (S120). Next, the TPMS valve 20RRin acquires information on the air pressure P2 of the wheel 14RRout included in the signal received from the TPMS valve 20RRout among the signals received by the wheel side communication device 22 (S122). The control circuit 23 of the TPMS valve 20RRin compares the air pressures P1 and P2 (S124), and if it is determined that the air pressure P2 is lower than the air pressure P1 (Yes in S124), information on the air pressure P2 and the ID of the wheel 14RRout A signal including the code is transmitted from the wheel side communicator 22 (S126). On the other hand, the control circuit 23 compares the air pressures P1 and P2 (S124), and determines that the air pressure P2 is not lower than the air pressure P1 (No in S124), the information on the air pressure P1 and the ID code of the wheel 14RRin. The included signal is transmitted from the wheel side communicator 22 (S128).

(Sixth embodiment)
In the present embodiment, a process for transmitting information to the ECU when there is any abnormality or failure in the TPMS valve that has shifted to the power saving transmission mode in each of the above-described embodiments will be described. FIG. 14 is a flowchart for explaining a procedure for determining information to be transmitted from the TPMS valve according to the sixth embodiment. Hereinafter, signal processing in the TPMS valve 20RRin that has shifted to the relay signal transmission mode by the processing described in FIG. 7 according to the first embodiment will be described as an example.

  For example, even if the TPMS valve 20RRout that has shifted to the power saving transmission mode has a value in an abnormal range of the air pressure and temperature of the wheel provided, the information is directly transmitted to the ECU 30 that is the wheel information processing device. I can't do it. Further, the TPMS valve 20RRout provides information to the wheel information processing apparatus when a circuit such as the air pressure sensor 21, the wheel side communication device 22, the control circuit 23 or the like fails and no radio wave is output, or when the wheel itself falls off the vehicle body. Cannot be transmitted to the ECU 30.

  Therefore, as shown in FIG. 14, when the wheel side communication device 22 included in the TPMS valve 20RRin receives a signal including the ID code or wheel information of another wheel transmitted by the TPMS valve 20RRout (Yes in S130), It is determined whether or not an abnormality flag is included in the signal (S132). When determining that the abnormality flag is included (Yes in S132), the control circuit 23 relays the signal including the abnormality flag and the ID code indicating the TPMS valve 20RRout and transmits the relayed signal to the ECU 30 (S134). The ECU 30 that has received the abnormality flag in the vehicle body side communication device 25 determines that there is some abnormality in the TPMS valve 20RRout (S136), and informs the user and the worker of the alarm device 27 such as a display on the screen, sound, and lamp. (S138). On the other hand, when it is determined that the abnormality flag is not included (No in S132), the control circuit 23 performs normal processing in the relay signal transmission mode (S140).

  Moreover, when a signal is not received in the wheel side communication apparatus 22 (No of S130), the control circuit 23 determines whether the state has continued for the predetermined time (S142). If no signal is received in the wheel side communication device 22, but the predetermined time has not elapsed (No in S142), the process returns to S130. When the wheel-side communication device 22 does not receive an appropriate signal transmitted from the TPMS valve 20RRout and a predetermined time has elapsed (Yes in S142), the control circuit 23 indicates a failure flag indicating that the TPMS valve 20RRout has failed. Is transmitted (S144). The ECU 30 that has received the failure flag in the vehicle body side communication device 25 determines that the TPMS valve 20RRout has failed (S146), and informs the user and the worker of the alarm device 27 such as display on the screen, sound, and lamp. (S148).

(Seventh embodiment)
In the present embodiment, a process for transmitting information to the ECU when there is any abnormality or failure in the TPMS valve that has shifted to the relay signal transmission mode in each of the above-described embodiments will be described. FIG. 15 is a flowchart for explaining a procedure for determining control in the TPMS valve according to the seventh embodiment. Hereinafter, signal processing in the TPMS valve 20RRout that has shifted to the power saving transmission mode by the processing described in FIG. 7 according to the first embodiment will be described as an example.

  For example, when the TPMS valve 20RRin that has shifted to the relay signal transmission mode fails, not only the signal including the information is not transmitted but also the wheel information of the one wheel 14RRout constituting the double tire is saved by the TPMS valve 20RRout. Since it has shifted to the transmission mode, the vehicle body side communication device 25 is not reached. That is, wheel information of both wheels constituting the double tire is not transmitted to the ECU at all.

  Accordingly, as shown in FIG. 15, it is determined whether or not the wheel side communication device 22 provided in the TPMS valve 20RRout has received a signal including the ID code and wheel information of the other wheels transmitted by the TPMS valve 20RRin (S150). When the wheel side communicator 22 receives a signal including an ID code of other wheels or wheel information (Yes in S150), the control circuit 23 performs normal processing in the power saving transmission mode as it is (S162). If no signal is received in the wheel side communication device 22, but the predetermined time has not elapsed (No in S150, No in S152), the process returns to S150. When the wheel-side communicator 22 does not receive an appropriate signal transmitted from the TPMS valve 20RRin and a predetermined time has elapsed (No in S150, Yes in S152), the control circuit 23 indicates that the TPMS valve 20RRin has failed. to decide.

  Then, the control circuit 23 changes the transmission output in the wheel side communication device 22 to a predetermined reference output (S154), and the wheel information such as the ID code of the own wheel, the air pressure, and the TPMS valve 20RRin are out of order. A signal including the indicated failure flag is transmitted (S156). The ECU 30 that has received the failure flag in the vehicle body side communication device 25 determines that the TPMS valve 20RRin is out of order (S158), and informs the user and the worker of the alarm device 27 such as a display on the screen, sound, and lamp. (S160). Accordingly, it is possible to easily detect that the other TPMS valve 20 included in the other wheel 14RRin constituting the double tire with the own wheel 14RRout is broken. Moreover, since the failure of the other TPMS valve 20RRin is determined by the TPMS valve 20RRout itself, the load of signal processing in the ECU 30 can be reduced. Even if the TPMS valve 20RRin breaks down, at least wheel information of the TPMS valve 20RRout is transmitted to the ECU 30, so that a higher level of fail-safe is achieved.

  As described above, the present invention has been described with reference to the above-described embodiments. However, the present invention is not limited to the above-described embodiments, and the configurations of the embodiments are appropriately combined or replaced. Those are also included in the present invention. Various modifications such as design changes can be added to each embodiment based on the knowledge of those skilled in the art, and the embodiments to which such modifications are added are also included in the scope of the present invention. sell.

It is a schematic block diagram which shows the vehicle provided with the wheel information transmission apparatus and wheel information processing apparatus which concern on 1st Embodiment. It is sectional drawing which shows the principal part of the wheel provided with the TPMS valve | bulb. It is a block diagram for demonstrating the TPMS valve | bulb contained in the vehicle of FIG. FIG. 4A is a schematic diagram showing a state of transmission at a normal reference output of a TPMS valve provided in a wheel constituting the double tire, and FIG. 4B is provided in a wheel constituting the double tire. It is the model which shows the mode of transmission in the power saving transmission mode of the TPMS valve. It is a flowchart for demonstrating the procedure which determines whether the wheel provided with each TPMS valve | bulb of FIG. 1 is either a double tire. It is the figure which showed typically the intensity | strength of the signal received in the TPMS valve | bulb provided in one wheel of the double tire. FIG. 6 is a flowchart for explaining a procedure for determining whether a wheel provided with a TPMS valve in the process of FIG. 5 is one of double tires and a wheel determined to be one of the double tires; is there. It is a flowchart for demonstrating the procedure which registers whether the wheel in which each TPMS valve is provided in the wheel state monitoring system which concerns on 2nd Embodiment comprises a double tire. It is a figure which shows the structure of the transmission data transmitted from the wheel side communication apparatus of a TPMS valve. FIG. 9 is a flowchart for explaining a procedure for determining whether a wheel provided with a TPMS valve in the process of FIG. 8 is one of a double tire and a wheel registered as one of the double tires; is there. It is a flowchart for demonstrating the procedure which registers the information of the mounting position of each wheel with which each TPMS valve | bulb of FIG. 1 is provided with the wheel information processing apparatus with the identification information of the wheel. It is the figure which showed typically the intensity | strength of the acceleration detection signal according to the acceleration which generate | occur | produces in each rear wheel at the time of turning right at a fixed steering angle. It is a flowchart for demonstrating the procedure which determines the information transmitted from the TPMS valve | bulb which concerns on 5th Embodiment. It is a flowchart for demonstrating the procedure which determines the information transmitted from the TPMS valve | bulb which concerns on 6th Embodiment. It is a flowchart for demonstrating the procedure which determines the control in the TPMS valve | bulb which concerns on 7th Embodiment.

Explanation of symbols

  10 vehicle, 12 vehicle body, 14 wheel, 18 tire, 20 TPMS valve, 21 air pressure sensor, 22 wheel side communication device, 23 control circuit, 24 battery, 25 vehicle body side communication device, 26 sensor group, 27 alarm device, 30 ECU, 40 wheels, 42 acceleration sensors.

Claims (18)

A wheel state monitoring system in which a plurality of wheel information transmitting devices capable of transmitting wheel information related to wheels and a wheel information processing device that receives and processes the wheel information monitor the state of the wheels by transmitting and receiving information. There,
The wheel information transmitter is
A detection unit for detecting the wheel information;
A wheel-side transmitter that transmits identification information for identifying the own wheel from other wheels and a first wheel signal including the wheel information;
A wheel side receiver that receives a second wheel signal including other identification information and other wheel information transmitted from another wheel information transmitter;
A wheel-side control unit capable of determining whether its own wheel is one of the double tires or the other,
The wheel information processing apparatus
A vehicle body side receiving unit that receives the identification information of the own wheel transmitted from the wheel information transmitting device and a signal including the wheel information;
A vehicle body side control unit that estimates the state of the wheel provided with the wheel information transmission device based on the identification information of the wheel and the wheel information;
The wheel-side control unit in the wheel information transmission device of a wheel that has been determined that its own wheel is one of the double tires among the plurality of wheel information transmission devices, the wheel provided in the other of the double tires in the first wheel signal Shift to a power saving transmission mode in which the transmission output in the wheel side transmission unit is smaller than a predetermined reference output to the extent that it reaches the side reception unit,
The wheel-side control unit in the wheel information transmission device of a wheel that has been determined that the wheel of the plurality of wheel information transmission devices is the other of the double tires is transmitted from the wheel information transmission device that has shifted to the power saving transmission mode. And a transition to a relay signal transmission mode in which at least a part of the second wheel signal received by the wheel-side receiving unit is transmitted to the wheel information processing apparatus.   The wheel side transmission unit transmits the second wheel signal to the wheel information processing apparatus together with the first wheel signal when it is determined that its own wheel is the other of the double tires. The wheel state monitoring system according to claim 1.   The wheel side control unit compares the intensity of the signal received by the wheel side receiving unit with a predetermined threshold value, and determines whether or not its own wheel is a double tire. Or the wheel state monitoring system according to 2.   The wheel side control unit compares the identification information of the own wheel with other identification information included in the second wheel signal when the own wheel is one of the double tires, 4. The wheel condition monitoring system according to claim 1, wherein it is determined whether the tire is one or the other.   The wheel-side control unit, when its own wheel is one of double tires, when its own wheel is closer to the wheel information processing device than its own wheel and other wheels constituting the double tire, 2. The tire according to claim 1, wherein the wheel is determined to be the other of the tires, and the wheel is determined to be one of the double tires when the wheel is farther from the wheel information processing device than the other wheels. 4. The wheel state monitoring system according to any one of 3.   The wheel-side control unit is configured such that when the own wheel is one of double tires, the wheel side control unit is self when the own wheel is located on the outer side in the vehicle width direction of the vehicle body with respect to the own wheel and other wheels constituting the double tire. It is determined that the other wheel is one of the double tires, and when the own wheel is located on the inner side in the vehicle width direction of the vehicle body than the other wheels, the own wheel is determined to be the other of the double tires. The wheel state monitoring system according to any one of claims 1 to 3.   The wheel state monitoring system according to any one of claims 1 to 6, wherein the wheel side control unit switches between the power saving transmission mode and the relay signal transmission mode at a predetermined timing.   When the wheel side control unit has shifted to the relay signal transmission mode, the wheel side control unit compares the wheel information of its own wheel with other wheel information included in the second wheel signal, and the state of the wheel is The wheel state monitoring system according to any one of claims 1 to 7, wherein the wheel information of the wheel judged to be relatively good is not transmitted.   When the wheel side control unit determines that the other wheel information transmitting device included in the other wheel constituting the own tire and the double tire has failed, when the transition to the power saving transmission mode is made, the wheel side The wheel state monitoring system according to any one of claims 1 to 8, wherein a transmission output in the transmission unit is changed to a predetermined reference output.   When the wheel side control unit does not receive a signal transmitted from another wheel information transmitting device included in the other wheel constituting the self tire and the double tire in the wheel side receiving unit for a predetermined time or more, the first side The wheel state monitoring system according to claim 9, wherein a signal indicating that another wheel information transmitting device has failed together with a wheel signal is transmitted to the wheel information processing device. A wheel information transmission device capable of transmitting wheel information related to a wheel,
A detection unit for detecting the wheel information;
A wheel-side transmitter that transmits identification information for identifying the own wheel from other wheels and a first wheel signal including the wheel information;
A wheel side receiver that receives a second wheel signal including other identification information and other wheel information transmitted from another wheel information transmitter;
A wheel-side control unit capable of determining whether its own wheel is one of the double tires or the other,
The wheel side controller is
When it is determined that the own wheel is one of the double tires, the transmission output in the wheel side transmission unit is set to a predetermined reference output to the extent that the first wheel signal reaches the wheel side reception unit provided in the other of the double tires. Shift to a lower power saving transmission mode,
When it is determined that the own wheel is the other of the double tires, at least one of the second wheel signals transmitted from the other wheel information transmitting device included in one wheel of the double tire and received by the wheel-side receiving unit. The wheel information transmitting device is characterized in that it shifts to a relay signal transmission mode for transmitting the part.   The said wheel side transmission part transmits the said 2nd wheel signal with a said 1st wheel signal, when it determines with a self wheel being the other of a double tire, The said 2nd wheel signal is characterized by the above-mentioned. Wheel information transmitter.   The wheel-side control unit compares the intensity of the signal received by the wheel-side receiving unit with a predetermined threshold value, and determines whether or not its own wheel is a double tire. Or the wheel information transmitter of 12.   The wheel side control unit compares the identification information of the own wheel with other identification information included in the second wheel signal when the own wheel is one of the double tires, The wheel information transmitting device according to any one of claims 11 to 13, wherein the wheel information transmitting device determines whether the tire is one or the other.   The wheel information transmission device according to any one of claims 11 to 14, wherein the wheel-side control unit switches between the power saving transmission mode and the relay signal transmission mode at a predetermined timing.   When the wheel side control unit has shifted to the relay signal transmission mode, the wheel side control unit compares the wheel information of its own wheel with other wheel information included in the second wheel signal, and the state of the wheel is The wheel information transmitting device according to any one of claims 11 to 15, wherein the wheel information of the wheel judged to be relatively good is not transmitted.   When the wheel side control unit determines that the other wheel information transmitting device included in the other wheel constituting the own tire and the double tire has failed, when the transition to the power saving transmission mode is made, the wheel side The wheel information transmission device according to any one of claims 11 to 16, wherein the transmission output in the transmission unit is changed to a predetermined reference output.   When the wheel side control unit does not receive a signal transmitted from another wheel information transmitting device included in the other wheel constituting the self tire and the double tire in the wheel side receiving unit for a predetermined time or more, the first side The wheel information transmitting device according to claim 17, wherein a signal indicating that another wheel information transmitting device has failed is transmitted together with the wheel signal.

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