JP2013241152A - Tire monitoring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the quantity of installed initiators without increasing a cost.SOLUTION: In a tire monitoring device 14, when the receiving intensity of a request signal 17 exceeds a response threshold y, a sensor unit 15 transmits a response signal including specific ID information, and then comes into a sleep state. One initiator 18 is provided for the sensor unit 15. The sensor unit 15 is configured so that timings at which the receiving intensity exceeds the response threshold y are displaced from each other by receiving the request signal 17 from the initiator 18 with different receiving intensities. The initiator 18 is a variable output initiator capable of changing the transmission intensity of the request signal 17. Since a controller 22 makes the variable output initiator change the transmission intensity of the request signal 17, the response signal is transmitted in order starting at the sensor unit 15 at which the response threshold y is earlier exceeded.

Description

  The present invention relates to a tire monitoring device provided to monitor a state of a tire attached to a vehicle such as an automobile such as air pressure.

  Some vehicles such as automobiles are provided with a tire monitoring device for monitoring the condition of the tire (see, for example, Patent Document 1).

  For example, as shown in FIG. 5, the tire monitoring device of Patent Document 1 installs a sensor unit 3 for each tire 2 of the vehicle 1 and installs the tire 2 at a position close to each tire 2. One initiator 5 (antenna device) that transmits a request signal 4 having a transmission intensity that can be received only by the sensor unit 3 is provided.

  Each sensor unit 3 described above is configured to transmit a response signal 6 including unique ID information when receiving the request signal 4 from each initiator 5.

  Then, the request signal 4 is transmitted to each initiator 5 in order, and the receiver 7 receives the response signal 6 from each sensor unit 3 in order. It is possible to identify whether the response signal 6 is from the sensor unit 3 installed on the tire 2 at the position.

  However, since the tire monitoring device of Patent Document 1 described above requires one initiator 5 for each sensor unit 3, there is a problem that the device cost increases.

  Therefore, as disclosed in Patent Document 2, one that can handle a plurality of sensor units with one initiator has been developed.

  In Patent Document 2, an initiator is arranged at a position where reception strengths are different from each other with respect to a plurality of sensor units, and a request signal having a constant transmission strength that can be received by all target sensor units from this initiator. Each sensor unit measures the reception intensity of each received request signal and transmits the response signal with the data of the reception intensity together with the unique ID information. It is made to identify the response signal from the sensor unit installed in the tire at which tire position on the vehicle.

JP 2006-062516 A JP 2007-015491 A

  However, in the tire monitoring device described in Patent Document 2, it is necessary to provide each sensor unit with a measuring device for measuring the reception intensity, so that the effect of reducing the device cost cannot be sufficiently obtained, or On the other hand, there is a problem that the device cost becomes high, and when the response signal is loaded with the data of the reception intensity together with the unique ID information, another problem such as an increase in the amount of data of the response signal and a burden on communication occurs. .

  In order to solve the above-mentioned problem, the invention described in claim 1 includes a sensor unit installed in each tire of a vehicle, an initiator for transmitting a request signal to the sensor unit, and a sensor unit. In each of the tire monitoring devices comprising: a receiver that receives a response signal; and a controller that transmits a request signal to the initiator and processes a response signal received by the receiver to monitor a tire state. The sensor unit is configured to transmit a response signal including unique ID information when the received intensity of the received request signal exceeds a response threshold, and then enter a sleep state in which no response is temporarily made, and the initiator Is provided for each of the plurality of sensor units, and the plurality of sensors. The knit is configured to receive the request signal from the initiator at different reception strengths, so that the timing exceeding the response threshold is shifted, and the initiator can change the transmission strength of the request signal. In addition, the controller causes the variable output initiator to change the transmission intensity of the request signal, so that the response signal is transmitted in order from the sensor unit whose reception intensity of the request signal exceeds the response threshold first. It is characterized by being configured to transmit.

  The invention described in claim 2 is characterized in that, in the above, the initiator is installed at a position where the distance from each of the plurality of sensor units is different.

  The invention described in claim 3 is characterized in that, in the above, reception intensity adjusting means for adjusting reception intensity of a request signal is provided between the initiator and at least one of the plurality of sensor units. To do.

  The invention described in claim 4 is characterized in that, in the above, the reception intensity adjusting means is a radio wave shield that at least partially blocks a request signal.

  The invention described in claim 5 is characterized in that, in the above, the request signal transmitted from the variable output initiator is transmitted a plurality of times while increasing the transmission intensity.

  The invention described in claim 6 is characterized in that, in the above, the request signal transmitted from the variable output initiator has a series of waveforms whose transmission intensity increases stepwise.

  In the invention described in claim 7, in the above, one initiator is provided for the sensor unit located on the right side of the vehicle, and another one is provided for the sensor unit located on the left side of the vehicle. An initiator is provided, and each initiator is configured not to receive a request signal to a sensor unit located on the opposite side.

  The invention described in claim 8 is characterized in that, in the above, each initiator is arranged at a position where the request signal does not reach the sensor unit located on the opposite side.

  The invention described in claim 9 is characterized in that, in the above, each initiator transmits a request signal at a transmission intensity that does not reach a sensor unit located on the opposite side.

According to the first aspect of the present invention, the following operational effects can be obtained by the above configuration. That is, the controller first sends a request signal to the initiator. Then, the sensor unit receives a request signal from the initiator, and transmits a response signal including unique ID information when the received intensity of the received request signal exceeds the response threshold. The response signal from the sensor unit is received by the receiver and sent to the controller. The controller assigns each sensor unit to the tire position on the vehicle in a predetermined order in the order of reception of the response signal by the receiver, and registers the unique ID information at each tire position on the vehicle. Thereafter, the controller collates the unique ID information transmitted together with the data (data signal) indicating the tire state from each sensor unit with the unique ID information registered as described above, so that the data of the data signal is stored on the vehicle. The tire position at each tire position is identified and the state of each tire is monitored.
In addition, one initiator described above is provided for a plurality of sensor units, and the plurality of sensor units receive request signals from the initiator with different reception intensities, thereby setting a response threshold value. Try to make sure that the timing of overshooting is different. By doing so, it becomes possible to change the transmission timing of the response signal for each sensor unit by utilizing the difference in timing exceeding the response threshold due to the difference in reception intensity. As a result, the receiver can receive the response signal transmitted from each sensor unit at different timings, and the controller can store the unique ID information included in the response signal received by the receiver anywhere on the vehicle. The sensor unit installed on the tire at the tire position can be easily and accurately identified and registered, thereby reducing the number of installed initiators and reducing the equipment cost. It becomes possible.

  Further, the initiator described above is used as a variable output initiator, and the transmission intensity of the request signal transmitted from the variable output initiator is changed by the controller. As a result, it is possible to transmit the response signals in order from the sensor unit that has previously exceeded the response threshold.

That is, when the reception intensity of one sensor unit exceeds the response threshold due to a request signal having a low transmission intensity, the sensor unit transmits a response signal including unique ID information, and then does not respond temporarily. Enter sleep mode (standby mode).
When a request signal with a changed transmission strength (intensified) is transmitted while the sensor unit is in the sleep state, the reception strength of another sensor unit that is not in the sleep state exceeds the response threshold. Then, a response signal including unique ID information is transmitted, and thereafter, a sleep state (standby state) in which no response is temporarily made is entered.
As described above, if the response signals are sequentially transmitted at different timings, it is possible to prevent the response signals from the sensor units from being mixed.

  As a result, even if the number of initiators is reduced, it is possible to clearly identify and register the response signal from the sensor unit installed in the tire at which tire position on the vehicle. . Moreover, to put the sensor unit into the sleep state, it is only necessary to rewrite the internal program without changing the mechanical configuration, so the sensor unit does not become large or the sensor unit becomes expensive, In addition, the data amount of the response signal can be increased easily without causing a communication burden.

  According to the second aspect of the present invention, the following effects can be obtained by the above configuration. That is, since the initiator is installed at a position where the distance from each of the plurality of sensor units is different, the request signals from the initiator are transmitted to the plurality of sensor units at different reception strengths depending on the installation position of the initiator. It can be received. Accordingly, the timing at which the reception intensity of the request signal exceeds the response threshold value in each of the plurality of sensor units can be made different.

  According to the third aspect of the present invention, the following operational effects can be obtained by the above configuration. That is, since the reception intensity adjustment means for adjusting the reception intensity of the request signal is provided between the initiator and at least one of the plurality of sensor units, the reception intensity adjustment means is used to connect the plurality of sensor units. The request signal from the initiator can be adjusted to be received at different reception strengths. Accordingly, the timing at which the reception intensity of the request signal exceeds the response threshold value in each of the plurality of sensor units can be made different.

  According to the invention described in claim 4, the following effects can be obtained by the above-described configuration. That is, since the reception intensity adjusting means is a radio wave shield that at least partially blocks the request signal, the request signal reception intensity is reduced by reducing the request signal of any of the plurality of sensor units with the radio wave shield. The timing at which the response threshold is exceeded can be adjusted.

  According to the fifth aspect of the present invention, the following effects can be obtained by the above configuration. That is, the request signal transmitted from the variable output initiator is transmitted a plurality of times while increasing the transmission intensity. Since it can be made to transmit, a request signal can be transmitted efficiently without waste.

  According to the sixth aspect of the present invention, the following effects can be obtained by the above configuration. That is, the request signal transmitted from the variable output initiator has been made into a series of waveforms whose transmission intensity increases step by step, so that the request signal is received in order by multiple sensor units with a single request signal transmission. To be able to. Further, since it is not necessary to set or adjust the transmission intensity of the request signal according to the position of the sensor unit, it is possible to use the request signal having the same waveform regardless of the vehicle type. And it can identify that it is a sensor unit attached to the tire with the near position in the order which received the response signal.

  According to the seventh aspect of the present invention, the following effects can be obtained by the above configuration. That is, one initiator is provided for the sensor unit located on the right side of the vehicle, and another initiator is provided for the sensor unit located on the left side of the vehicle. By configuring so that the request signal does not reach the sensor unit located on the opposite side, it is possible to provide separate initiators for the right sensor unit and the left sensor unit. Thus, a device configuration with the highest feasibility and reliability can be obtained.

  According to the invention described in claim 8, the following effects can be obtained by the above-described configuration. That is, since each initiator is arranged at a position where the request signal does not reach the sensor unit located on the opposite side, the initiator is divided into two for the right sensor unit and for the left sensor unit. Can be divided reliably.

  According to the ninth aspect of the present invention, the following effects can be obtained by the above-described configuration. That is, each initiator transmits a request signal at a transmission intensity that does not reach the sensor unit located on the opposite side, so that the initiator can be used for the right sensor unit and the left sensor unit. It can be surely divided into two.

It is a lineblock diagram of the tire monitoring device concerning the example of the present invention. It is a block diagram of the tire monitoring apparatus concerning the other Example of this invention. It is a timing chart in case a request signal is output in multiple times. Among these, (a) is a graph showing the relationship between transmission intensity and time at the initiator, (b) is a graph showing the relationship between reception intensity and time at the sensor unit (RF, LF), and (c) is a sensor unit. (RF, LF) is a graph showing the relationship between the response signal and time, (d) is a graph showing the relationship between reception intensity and time at the sensor unit (RR, LR), and (e) is a sensor unit (RR, (LR) is a graph showing the relationship between the response signal and time, and (f) is a graph showing the relationship between the response signal and time in the receiver. It is a timing chart in case a request signal is a series of waveforms whose transmission intensity increases stepwise. Among these, (a) is a graph showing the relationship between transmission intensity and time at the initiator, (b) is a graph showing the relationship between reception intensity and time at the sensor unit (RF, LF), and (c) is a sensor unit. (RF, LF) is a graph showing the relationship between the response signal and time, (d) is a graph showing the relationship between reception intensity and time at the sensor unit (RR, LR), and (e) is a sensor unit (RR, (LR) is a graph showing the relationship between the response signal and time, and (f) is a graph showing the relationship between the response signal and time in the receiver. It is an apparatus block diagram of the tire monitoring apparatus concerning a prior art example.

  Hereinafter, examples embodying the present embodiment will be described in detail with reference to the drawings.

  1 to 4 show this embodiment and its modifications.

  <Configuration> The configuration will be described below.

  As shown in FIG. 1, a tire monitoring device 14 for monitoring the state of the tire 12 is provided in a vehicle 11 such as an automobile.

  The tire monitoring device 14 includes a sensor unit 15 installed in each tire 12 of the vehicle 11, an initiator 18 (antenna device) that transmits a request signal 17 to the sensor unit 15, and the sensor unit 15 described above. Receiver 21 that receives the response signal 19 (see FIG. 3). The tire monitoring device 14 includes a controller 22 that transmits the request signal 17 to the initiator 18 and processes the response signal 19 received by the receiver 21 to monitor the state of the tire 12. ing.

  Here, when supplementary explanation is given, first, four tires 12 are usually attached to the above-mentioned “vehicle 11”. There are four tire positions (or tire mounting positions) in the vehicle 11 including a right front wheel position (RF), a right rear wheel position (RR), a left front wheel position (LF), and a left rear wheel position (LR). . However, the number of tires 12 and the tire mounting position are not limited to the above.

  The “sensor unit 15” described above is attached to a valve portion or the like (not shown) of the tire 12. The sensor unit 15 includes a sensor unit that detects the state of the tire 12, a receiving unit that receives the request signal 17, a transmitting unit that transmits the response signal 19, and a unit that controls the sensor unit, the receiving unit, and the transmitting unit. And a control unit. The sensor section described above is provided with a pressure sensor that detects the air pressure of the tire 12, a temperature sensor that detects the temperature of the tire 12, and the like, and in addition, various sensors are provided as necessary. A microcomputer etc. are used for the above-mentioned unit control part, for example. Sensor units 15 having the same performance (reception sensitivity, etc.) are used.

  The above-mentioned “controller 22” includes a transmission control unit that controls the initiator 18, a reception control unit that controls the receiver 21, and a signal processing unit that processes the response signal 19 from the sensor unit 15. And have. For the controller 22, for example, a microcomputer or the like is used.

  The controller 22 and the initiator 18 are connected by wire or wireless. Moreover, the controller 22 and the receiver 21 are comprised integrally, or are comprised separately and are connected by wire or radio | wireless. For example, the receiver 21 is often provided separately from the controller 22 for the purpose of installing the receiver 21 at a position with the best reception state. The controller 22 is connected to a notification device 23 such as a display device, an alarm sound generation device, and an audio output device as necessary.

  The operation of the tire monitoring device 14 includes an initial operation that is performed when the ignition switch of the vehicle 11 is turned on and a normal operation that is performed during normal traveling.

  In the initial operation described above, from the tire 12 at which tire position (RF, RR, LF, LR) on the vehicle 11 is the data indicating the state of the tire 12 transmitted from each sensor unit 15 in the normal operation described later. The registration is updated every time the engine of the vehicle 11 is started so that it can be identified. By performing such an initial operation, for example, even when the tire 12 is rotated, the correspondence between the tire position on the vehicle 11 and each tire 12 is automatically reset. Even if the registration is not manually changed, the data indicating the state of the tire 12 from each sensor unit 15 is from the tire 12 (the sensor unit 15) at which tire position on the vehicle 11. Can be recognized correctly.

  On the other hand, in the normal operation described above, the data indicating the state of the tire 12 sent along with the unique ID information from the sensor unit 15 attached to each tire 12 is processed to monitor the state of each tire 12 during traveling. Is.

  This embodiment mainly relates to the above-described initial operation, and for this purpose, the following configuration is provided.

  In the present embodiment, the term “reception strength” is used for convenience, but this is intended to express the difference in signal reception status in each sensor unit 15 in an easy-to-understand manner. It does not mean the measured reception strength. Therefore, in this embodiment, since the reception intensity is not measured, it is not necessary to provide each sensor unit 15 with a measuring device for measuring the reception intensity.

(Configuration 1)
First, each sensor unit 15 transmits a response signal 19 including unique ID information when the reception intensity (or reception level) of the received request signal 17 exceeds the response threshold y (see FIG. 3). In addition, it is configured to enter a sleep state in which no response is temporarily made (sleep capable sensor unit).

  One initiator 18 is provided for the plurality of sensor units 15 described above. The plurality of sensor units 15 receive the request signal 17 from the initiator 18 at different reception intensities so that the timings exceeding the response threshold y are shifted.

  Further, the initiator 18 described above is a variable output initiator that can change the transmission intensity of the request signal 17.

  Then, the controller 22 causes the variable output initiator to change the transmission intensity of the request signal 17 so that the reception intensity of the request signal 17 first exceeds the response threshold y from the sensor unit 15 in order. Is configured to transmit a response signal 19.

(Supplementary explanation 1)
Here, the above-mentioned “response threshold y” is set to the same value by unifying all the sensor units 15 to have the same performance (reception sensitivity) and using them with the same settings.
The “sleep state” described above may be performed for a predetermined time set for the initial operation, or may be performed until all the sensor units 15 transmit the response signal 19. May be. Then, when a predetermined time has elapsed or when all the sensor units 15 have completed the transmission of the response signal 19, the sleep state is canceled and the normal operation is started. At this time, the sensor unit 15 may automatically cancel the sleep state by counting a timer or the like, or the controller 22 may cause the initiator 18 to transmit a release signal for canceling the sleep state. The sleep state may be canceled.

  “A plurality of sensor units 15 receive the request signal 17 from the initiator 18 at different reception intensities” means that even if the sensor units 15 have exactly the same performance, the reception intensities are different if the installation environment, installation conditions, and the like are different. Is to intentionally make a difference in the received intensity by utilizing the fact that becomes different.

  “Changing the transmission strength of the request signal 17” means that the request signal 17 having different transmission strengths is transmitted a plurality of times, or the transmission strength is changed during one transmission of the request signal 17, as will be described later. Etc. are included.

  “The reception intensity of the request signal 17 exceeds the response threshold y first” means that the sensor unit 15 placed in an environment in which the reception state of the request signal 17 is good increases the reception intensity of the request signal 17. It means that y can be exceeded. For example, it can be said that the sensor unit 15 closer to the initiator 18 is in an environment in which the reception state of the request signal 17 is better, so the response threshold y is quickly exceeded.

(Configuration 2)
In the above, the above-described initiator 18 is installed at a position where the distance from each of the plurality of sensor units 15 is different.

(Supplementary explanation 2)
As shown in FIG. 1, by placing the right initiator 18 (R) in front of the middle position between the right front wheel position (RF) and the right rear wheel position (RR) (D1 <D2), The closest to the tire 12 at the right front wheel position (RF), the second closest to the tire 12 at the right rear wheel position (RR), the third closest to the tire 12 at the left front wheel position (LF), It is arranged at a position farthest from the tire 12 at the left rear wheel position (LR).
Similarly, by installing the left initiator 18 (L) in front of the intermediate position between the left front wheel position (LF) and the left rear wheel position (LR) (D1 <D2), the left front wheel position ( LF) tire 12 closest, second rear wheel position (LR) second closest tire, right front wheel position (RF) third closest tire 12, right rear wheel position It is arranged at a position farthest from the tire 12 of (RR).

  However, depending on the structure of the vehicle 11, the mounting position of the initiator 18, and the like, the reception intensity may not be determined simply by the distance. In such a case, the reception intensity is measured and the accurate installation position is determined. To decide.

(Configuration 3)
In the above, as shown in FIG. 2, reception intensity adjusting means 31 that adjusts the reception intensity of the request signal 17 is provided between the initiator 18 and at least one of the plurality of sensor units 15. .

(Supplementary explanation 3)
The “reception strength adjusting means 31” described above may be a means for increasing the reception strength of the request signal 17 or a means for reducing the reception strength of the request signal 17. The reception intensity adjusting means 31 includes a physical one and an electric one. For example, the electrical reception intensity adjusting means 31 may be an amplifying apparatus that relays the request signal 17 to increase the reception intensity, or an attenuating apparatus that obstructs the request signal 17 and decreases the reception intensity.

(Configuration 4)
In the above, the reception intensity adjusting means 31 described above is the radio wave shield 32 that at least partially blocks the request signal 17.

(Supplementary explanation 4)
Here, the above-mentioned “radio wave shielding object 32” can be formed of a metal plate or the like having a characteristic of shielding radio waves. For example, the radio wave shield 32 does not completely block the request signal 17 between the initiator 18 and the sensor unit 15 that attempts to weaken the reception intensity (or delays transmission of the response signal 19). Install in. In this case, the sensor unit 15 is installed near the sensor unit 15 whose reception intensity is to be weakened.

For example, as shown in FIG. 2, such a radio wave shield 32 is provided with the right initiator 18 (R) approximately in the middle between the right front wheel position (RF) and the right rear wheel position (RR). Thus (D3 = D4), it can be used when the distance between the tire 12 at the right front wheel position (RF) and the tire 12 at the right rear wheel position (RR) becomes equal.
Similarly, by installing the left initiator 18 (L) at an intermediate position between the left front wheel position (LF) and the left rear wheel position (LR) (D3 = D4), the left front wheel position (LF) It can be used when the distance between the tire 12 and the tire 12 at the left rear wheel position (LR) becomes equal.

  However, as described above, the electromagnetic wave shielding object 32 can be used even in the case where the initiator 18 is installed at a position where the distance from each of the plurality of sensor units 15 is different as shown in FIG. is there.

(Configuration 5)
As shown in FIG. 3, the request signal 17 transmitted from the variable output initiator described above is transmitted a plurality of times while increasing the transmission intensity (for each transmission).

(Supplementary explanation 5)
3A, 3B, and 3D, for example, at time A1, only the sensor unit 15 (RF, LF) responds with the best reception state (the highest reception strength (the reception level is high)). A request signal 17 of the first transmission intensity that can be received with a reception intensity exceeding the threshold value y is transmitted, and at time A2, the sensor unit 15 (RR, LR) responds with the next best reception state (the next highest reception intensity). A second request signal 17 having a transmission intensity that can be received with a reception intensity exceeding the threshold y (the sensor unit 15 having the strongest reception intensity can also be received with a reception intensity exceeding the response threshold y) is output.

  On the other hand, as shown in FIGS. 3B and 3C, the sensor unit 15 (RF, LF) having the strongest reception strength receives the first request signal 17 with a reception strength exceeding the response threshold y. As a result, the response signal 19 is transmitted, and then the sleep state is entered.

  Further, as shown in FIGS. 3D and 3E, the sensor unit 15 (RR, LR) having the next strongest reception strength receives the second request signal 17 with a reception strength exceeding the response threshold y. Thus, the response signal 19 is transmitted, and then the sleep state is entered. At this time, since the sensor unit 15 (RF, LF) having the strongest reception intensity has already entered the sleep state, the response signal 19 is not transmitted.

  Then, as shown in FIGS. 3A and 3F, the receiver 21 responds from the sensor unit 15 having the highest reception strength by the request signal 17 transmitted a plurality of times while increasing the transmission strength as described above. The signal 19 and the response signal 19 from the sensor unit 15 having the next highest reception intensity can be received at different timings.

  Here, the “request signal 17” is a plurality of square waves transmitted intermittently. However, the waveform of the request signal 17 is not particularly limited to a square wave.

  The request signal 17 may be transmitted by changing (intensifying) the transmission intensity at regular time intervals. Alternatively, the request signal 17 may be transmitted by sequentially changing the transmission intensity while confirming the response signal 19 from the sensor unit 15.

  In this case, the request signal 17 is transmitted with two different transmission strengths to the two sensor units 15, but is transmitted with three or more different transmission strengths to the three or more sensor units 15. You may be made to do.

  Further, if the response signal 19 cannot be confirmed, the controller 22 may repeat the request signal 17 once again with the same transmission intensity or until the response signal 19 is confirmed.

  However, it goes without saying that the interval at which the request signal 17 is transmitted is shorter than the time during which the sensor unit 15 is in the sleep state.

(Configuration 6)
Alternatively, as shown in FIG. 4, the request signal 17 (one time) transmitted from the initiator 18 (variable output initiator) described above is made into a series of waveforms in which the transmission intensity increases stepwise. May be.

(Supplementary explanation 6)
In FIG. 4A described above, the initiator 18 starts transmitting the request signal 17 at time B0, for example, and continues to transmit a series of waveforms whose transmission intensity increases stepwise for a predetermined time. Yes.

  Then, as shown in FIGS. 4B and 4D, the request signal 17 is received by the response threshold y only at the sensor unit 15 (RF, LF) having the best reception state (the strongest reception intensity) at time B1. At time B2, the sensor unit 15 (RR, LR) having the next best reception state (the next strongest reception strength) can receive at the reception strength exceeding the response threshold y (reception). The sensor unit 15 having the strongest intensity can also receive with a reception intensity exceeding the response threshold y.) When the transmission intensity is increased and the transmission intensity is further increased and a predetermined time has elapsed, the transmission of the request signal 17 is terminated. .

  On the other hand, as shown in FIGS. 4B and 4C, the sensor unit 15 (RF, LF) having the strongest reception strength receives the request signal 17 at a reception strength exceeding the response threshold y at time B1. Thus, the response signal 19 is transmitted, and then the sleep state is entered.

  Also, as shown in FIGS. 4D and 4E, the sensor unit 15 (RR, LR) having the next strongest reception intensity receives the request signal 17 at a reception intensity exceeding the response threshold y at time B2. The response signal 19 is transmitted, and then the sleep state is entered. At this time, the sensor unit 15 (RF, LF) having the strongest reception intensity is already in the sleep state, and therefore does not transmit the response signal 19.

  Then, as shown in FIG. 4 (f), the receiver 21 receives the response signal 19 from the sensor unit 15 having the strongest reception intensity by the series of request signals 17 whose transmission intensity becomes stronger in stages as described above. Then, the response signal 19 from the sensor unit 15 having the next highest reception intensity can be received at different timings.

  Here, a series of waveforms whose transmission intensity increases stepwise is generally called a ramp waveform. In this case, the above-described (ramp) waveform has a transmission intensity that increases stepwise from a transmission intensity 0 to a transmission intensity MAX in a certain time.

(Configuration 7)
Preferably, as shown in FIG. 1 or FIG. 2, one initiator 18 (R) is provided for the sensor unit 15 (RF, RR) located on the right side of the vehicle 11. Further, another initiator 18 (L) is provided for the sensor unit 15 (LF, LR) located on the left side of the vehicle 11.

  Then, as shown in FIG. 1, each initiator 18 (R) (L) receives the request signal 17 to the sensor unit 15 (LF, LR) and the sensor unit 15 (RF, RR) located on the opposite side. Configured to not.

(Supplementary explanation 7)
For this purpose, for example, it is conceivable to block the left and right radio wave environments using the reception intensity adjusting means 31 (the radio wave shield 32 or the like) described above.

(Configuration 8)
Alternatively, each initiator 18 (R) (L) is arranged at a position where the request signal 17 does not reach the sensor unit 15 (LF, LR) and the sensor unit 15 (RF, RR) located on the opposite side. To do.

(Configuration 9)
Further, for example, each initiator 18 (R) (L) transmits the request signal 17 with a transmission intensity that does not reach the sensor unit 15 (LF, LR) and the sensor unit 15 (RF, RR) located on the opposite side. It is supposed to be.

(Supplementary explanation 9)
In this case, the maximum transmission intensity of the request signal 17 of each initiator 18 (R) (L) does not reach the sensor unit 15 (LF, LR) and the sensor unit 15 (RF, RR) located on the opposite side. Set and adjust as follows. Alternatively, the maximum output of each initiator 18 (R) (L) does not reach the sensor unit 15 (LF, LR) and the sensor unit 15 (RF, RR) located on the opposite side.

  Note that the configuration 8 and the configuration 9 may be combined.

  In addition to the structure described above, it is also possible to provide a single initiator 18 for the sensor units 15 provided on all the tires 12 of the vehicle 11. In this case, one initiator 18 is a variable output initiator capable of transmitting a request signal 17 having a transmission strength that can be received at a reception strength that all the sensor units 15 exceed the response threshold value y. The configurations 1 to 6 are appropriately combined.

  <Operation> The basic operation of this embodiment will be described below.

  When the ignition switch of the vehicle 11 is turned on, the tire monitoring device 14 first causes the controller 22 to send the request signal 17 to the initiator 18 as an initial operation. Then, the sensor unit 15 receives the request signal 17 from the initiator 18 and transmits a response signal 19 including unique ID information when the received intensity of the received request signal 17 exceeds the response threshold y. The response signal 19 from the sensor unit 15 is received by the receiver 21 and sent to the controller 22. The controller 22 assigns each sensor unit 15 to the tire position on the vehicle 11 in the order of reception of the response signal 19 by the receiver 21 and assigns the unique ID information to each tire position on the vehicle 11. sign up. By this registration, the controller 22 checks the unique ID information transmitted together with the data indicating the state of the tire 12 from each sensor unit 15 in the normal operation with the unique ID information registered by the initial operation, thereby obtaining the data. Can be identified from the sensor unit 15 installed on the tire 12 at which tire position on the vehicle 11.

More specific registration procedures are, for example, divided on the left and right of the vehicle 11, and on the right side, the right front wheel position (RF) transmits the response signal 19 first, and then the right rear wheel position (RR). Next, the response signal 19 is set to be transmitted. On the left side, the left front wheel position (LF) first transmits the response signal 19, and then the left rear wheel position (LR) is the next response signal 19. Is assigned to the right front wheel position (RF) and the left front wheel position (LF), and the next received response is assigned to the unique ID information included in the response signal 19 received first. The unique ID information included in the signal 19 is assigned and registered to the right rear wheel position (RR) and the left rear wheel position (LR).
However, this assignment may be such that the right front wheel position (RF) and the left front wheel position (LF) are reversed from the right rear wheel position (RR) and the left rear wheel position (LR).

  Thus, when the initial operation is completed, as a normal operation, each sensor unit 15 transmits data (air pressure, temperature, etc.) indicating the state of the tire 12 together with its unique ID information at regular intervals. Identifies the tire position by comparing the unique ID information included in the data (data signal) sent from each sensor unit 15 with the unique ID information registered by the initial operation, and is included in the data signal. The state of each tire 12 such as running is monitored based on the data.

  When the controller 22 determines that an abnormality has occurred, the controller 22 notifies the occupant of the abnormality using the notification device 23.

  <Effect> According to this embodiment, the following effects can be further obtained.

(Effect 1)
First, one initiator 18 is provided for each of the plurality of sensor units 15, and the plurality of sensor units 15 receive the request signal 17 from the initiator 18 with different reception strengths. Thus, the timings exceeding the response threshold y are shifted from each other. In this way, the transmission timing of the response signal 19 can be changed for each sensor unit 15 by using the difference in timing exceeding the response threshold y due to the difference in reception intensity. As a result, the receiver 21 can receive the response signals 19 transmitted from the sensor units 15 at different timings, and the controller 22 stores the unique ID information included in the response signal 19 received by the receiver 21. It is possible to easily identify and register the sensor unit 15 installed in the tire 12 at which tire position on the vehicle 11, and thus the number of installed initiators 18 can be determined. It is possible to reduce the device cost by reducing the cost.

  Further, the initiator 18 described above is used as a variable output initiator, and the transmission intensity of the request signal 17 transmitted from the variable output initiator is changed by the controller 22. As a result, the response signal 19 can be transmitted in order from the sensor unit 15 that has previously exceeded the response threshold y.

That is, when the reception intensity of one sensor unit 15 exceeds the response threshold value y by the request signal 17 having a low transmission intensity, the sensor unit 15 transmits a response signal 19 including unique ID information, and then temporarily The device enters a sleep state (standby state) in which no response is made.
Then, when the request signal 17 whose transmission intensity is changed (enhanced) is transmitted while the sensor unit 15 is in the sleep state, the reception intensity of another sensor unit 15 that is not in the sleep state responds. A response signal 19 including unique ID information is transmitted beyond the threshold value y, and then a sleep state (standby state) in which no response is made temporarily is entered.
As described above, if the response signals 19 are sequentially transmitted at different timings, the response signals 19 from the sensor units 15 can be prevented from being mixed.

  As a result, even if the number of initiators 18 is reduced, it is possible to clearly identify and register the response signal 19 from the sensor unit 15 installed in the tire 12 at which tire position on the vehicle 11. It becomes possible. In addition, the sensor unit 15 can be put into the sleep state only by rewriting the internal program without changing the mechanical configuration, so that the sensor unit 15 becomes large or the sensor unit 15 becomes expensive. Without being increased, and the data amount of the response signal 19 can be increased without causing a communication burden.

(Effect 2)
Since the initiator 18 is installed at a position where the distance from each of the plurality of sensor units 15 is different, the request signal 17 from the initiator 18 is sent to the plurality of sensor units 15 depending on the installation position of the initiator 18. It is possible to receive at different reception strengths. Therefore, the timing at which the reception intensity of the request signal 17 exceeds the response threshold y in each of the plurality of sensor units 15 can be made different.

(Effect 3)
Since the reception intensity adjustment means 31 for adjusting the reception intensity of the request signal 17 is provided between the initiator 18 and at least one of the plurality of sensor units 15, the reception intensity adjustment means 31 is used to The sensor unit 15 can be adjusted to receive the request signal 17 from the initiator 18 at different reception strengths. Therefore, the timing at which the reception intensity of the request signal 17 exceeds the response threshold y in each of the plurality of sensor units 15 can be made different.

(Effect 4)
Since the reception intensity adjusting means 31 is the radio wave shield 32 that at least partially blocks the request signal 17, the radio wave shield 32 reduces the reception state of any of the request signals 17 of the plurality of sensor units 15. The timing at which the reception intensity of the request signal 17 in the sensor unit 15 exceeds the response threshold y can be adjusted.

(Effect 5)
As shown in FIG. 3, the request signal 17 transmitted from the variable output initiator is output a plurality of times while increasing the output (every time it is transmitted), so that each sensor unit 15 is received. Since the request signal 17 having the optimum transmission strength can be transmitted in the order of good condition, the request signal 17 can be transmitted efficiently without waste.

(Effect 6)
As shown in FIG. 4, the request signal 17 transmitted (one time) from the variable output initiator is made into a series of waveforms whose transmission intensity increases step by step. The request signals 17 can be received in order by the plurality of sensor units 15. Further, since it is not necessary to set or adjust the transmission intensity of the request signal 17 according to the position of the sensor unit 15 or the like, the request signal 17 having the same waveform can be used regardless of the vehicle type. . And it can identify that it is the sensor unit 15 attached to the tire 12 with a near position in the order which received the response signal 19. FIG.

(Effect 7)
As shown in FIG. 1, one initiator 18 (R) is provided for the sensor unit 15 (RF, RR) located on the right side of the vehicle 11, and the sensor unit 15 ( LF, LR) is provided with another initiator 18 (L), and each initiator 18 (R) (L) is located on the opposite side of the sensor unit 15 (LF, LR) and the sensor unit. Since the request signal 17 does not reach 15 (RF, RR), the initiator 18 is used for the right sensor unit 15 (RF, RR) and the left sensor unit 15 (LF, LR). In addition, it is possible to provide the device structure in two distinctly, and it is possible to obtain a device configuration with the highest feasibility and reliability.

(Effect 8)
Since each initiator 18 (R) (L) is arranged at a position where the request signal 17 does not reach the sensor unit 15 (LF, LR) and the sensor unit 15 (RF, RR) located on the opposite side, The attenuator 18 can be surely divided into two types, one for the right sensor unit 15 (R) and the other for the left sensor unit 15 (L).

(Effect 9)
Each initiator 18 (R) (L) transmits the request signal 17 at a transmission intensity that does not reach the sensor unit 15 (LF, LR) and the sensor unit 15 (RF, RR) located on the opposite side. As a result, the initiator 18 can be reliably divided into the right sensor unit 15 (RF, RR) and the left sensor unit 15 (LF, LR).

  Although the embodiments of the present invention have been described in detail with reference to the drawings, the embodiments are only examples of the present invention, and the present invention is not limited to the configurations of the embodiments. Needless to say, design changes and the like within a range not departing from the gist of the invention are included in the present invention. Further, for example, when each embodiment includes a plurality of configurations, it is a matter of course that possible combinations of these configurations are included even if not specifically described. Further, when a plurality of embodiments and modifications are shown, it is needless to say that possible combinations of configurations extending over these are included even if not specifically described. Further, the configuration depicted in the drawings is of course included even if not particularly described. Further, when there is a term of “etc.”, it is used in the sense that the equivalent is included. In addition, when there are terms such as “almost”, “about”, “degree”, etc., they are used in the sense that they include those in the range and accuracy recognized by common sense.

11 Vehicle 12 Tire 14 Tire Monitoring Device 15 Sensor Unit 17 Request Signal 18 Initiator (Variable Output Initiator)
19 Response signal 21 Receiver 22 Controller 23 Notification device 31 Receiving intensity adjustment means 32 Radio wave shield y Response threshold

Claims (9)

A sensor unit installed on each tire of the vehicle;
An initiator for transmitting a request signal to the sensor unit;
A receiver for receiving a response signal from the sensor unit;
In the tire monitoring device comprising a controller for transmitting a request signal to the initiator and processing a response signal received by the receiver to monitor a tire state,
Each sensor unit is configured to send a response signal including unique ID information when the received intensity of the received request signal exceeds the response threshold y, and then enter a sleep state in which no response is made temporarily,
One initiator is provided for a plurality of the sensor units,
The plurality of sensor units are configured such that timings exceeding the response threshold y are shifted by receiving request signals from the initiator with different reception intensities,
The initiator is a variable output initiator that can change the transmission intensity of the request signal, and the controller causes the variable output initiator to change the transmission intensity of the request signal. A tire monitoring apparatus, wherein a response signal is transmitted in order from a sensor unit whose reception intensity exceeds a response threshold y first.   The tire monitoring device according to claim 1, wherein the initiator is installed at a position where the distance from each of the plurality of sensor units is different.   The tire monitoring apparatus according to claim 1, wherein a reception intensity adjusting unit that adjusts a reception intensity of a request signal is provided between the initiator and at least one of the plurality of sensor units.   4. The tire monitoring apparatus according to claim 3, wherein the reception intensity adjusting means is a radio wave shield that at least partially blocks a request signal.   The tire monitoring device according to any one of claims 1 to 4, wherein the request signal transmitted from the variable output initiator is output a plurality of times while increasing the output.   The tire monitoring device according to any one of claims 1 to 4, wherein the request signal transmitted from the variable output initiator has a series of waveforms in which the transmission intensity increases stepwise. . One initiator is provided for the sensor unit located on the right side of the vehicle,
Another initiator is provided for the sensor unit located on the left side of the vehicle,
The tire monitoring device according to any one of claims 1 to 6, wherein each initiator is configured so that a request signal does not reach a sensor unit located on the opposite side.   8. The tire monitoring apparatus according to claim 7, wherein each initiator is arranged at a position where a request signal does not reach a sensor unit located on the opposite side.   8. The tire monitoring device according to claim 7, wherein each initiator transmits a request signal at a transmission intensity that does not reach a sensor unit located on the opposite side.