JP2012166680A - Tire air pressure monitoring system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tire air pressure monitoring system capable of preventing a broken piece of a burst tire from contacting with a pedestrian.SOLUTION: This tire air pressure monitoring system detects the air pressure of the tire via sensor units U1-U4 arranged at respective wheels W1-W4 of a vehicle, and issues a warning via a display part 11 arranged in a cabin when detecting an abnormality in the detected air pressure of the tire. Here, when the abnormality in the air pressure of the tire is detected, the rumbling of a horn 14 and the flashing of a hazard lamp 15 are performed on condition that the vehicle is in traveling at a low speed.

Description

  The present invention relates to a tire air pressure monitoring system for monitoring the air pressure of a vehicle tire.

  2. Description of the Related Art In recent years, a tire pressure monitoring system that monitors a tire pressure of a vehicle and issues a warning when an abnormality is detected in the tire pressure is known. Conventionally, as this type of tire pressure monitoring system, for example, a system described in Patent Document 1 is known.

  In the tire pressure monitoring system described in Patent Document 1, a sensor unit for detecting tire air pressure is provided on each wheel of a vehicle. When detecting the air pressure of the tire, the sensor unit generates and transmits a radio signal including information on the detected air pressure. And the radio signal transmitted from the sensor unit is received by the monitoring device provided in the vehicle. The monitoring device monitors the tire air pressure of each wheel based on the information on the air pressure included in the received wireless signal, and issues a warning in the following manner when an abnormality is detected in the tire air pressure. First, when the user is in the vehicle, a warning is given to the user in the passenger compartment by turning on a lamp provided in the passenger compartment. Further, when the user is not in the vehicle, when the user approaches the vehicle, a warning is given to the user outside the passenger compartment, for example, by turning on a headlamp.

  According to such a configuration as the tire pressure monitoring system, the user can recognize an abnormality in tire pressure by turning on a headlamp or the like when approaching the vehicle to get on. For this reason, since it is possible to perform repair work such as replenishing tire air or switching to a spare tire before boarding, convenience is improved.

JP-A-2005-247132

  By the way, for example, when the vehicle is driven while the tire air pressure is abnormal, there is a possibility that a so-called burst occurs in which the tire abnormally generates heat and the tire cannot withstand the heat and bursts. When the tire reaches a burst in this way, the tire fragments are scattered around the vehicle, and the scattered tire fragments may come into contact with pedestrians around the vehicle.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a tire pressure monitoring system capable of preventing a burst of tire fragments from coming into contact with a pedestrian.

  In order to solve the above-described problem, the invention according to claim 1 detects the air pressure of the tire mounted on the wheel through a sensor unit provided on the wheel of the vehicle, and detects the tire pressure detected through the sensor unit. In a tire pressure monitoring system that issues an alarm through alarm means provided in the vehicle when an abnormality is detected in the air pressure, the vehicle is provided with an out-of-cabin alarm means that issues an alarm outside the vehicle compartment as the alarm means, and is detected through the sensor unit. The gist is that when an abnormality is detected in the tire air pressure, an alarm is issued by the out-of-cabin alarm means on condition that the vehicle is running.

  According to this configuration, if an abnormality occurs in the tire air pressure while the vehicle is running, an alarm is issued through the vehicle exterior alarm means. Therefore, pedestrians around the vehicle can recognize an abnormality in tire air pressure through an alarm from the vehicle exterior alarm means, and can take avoidance actions such as leaving the vehicle before the tire reaches the burst. Become. For this reason, it is possible to prevent the burst tire fragments from coming into contact with the pedestrian.

  According to a second aspect of the present invention, in the tire air pressure monitoring system according to the first aspect, the vehicle speed is lower than a preset low speed judgment value as a condition for issuing an alarm by the outside alarm means. The gist is that it further includes speed.

  In situations where the vehicle is traveling at a high speed, even if an alarm is given by an out-of-cabin alarm means, it is difficult for pedestrians to immediately take actions such as leaving the vehicle, so a sufficient warning effect cannot be obtained. Of course, such warnings can also cause pedestrian confusion. Therefore, as in the above-described configuration, it is possible to obtain a sufficient warning effect while avoiding pedestrian confusion by issuing an alarm by the outside vehicle alarm means only when the vehicle is traveling at a low speed. become able to.

  According to a third aspect of the present invention, in the tire pressure monitoring system according to the first or second aspect, the tire may possibly burst as a condition for issuing an alarm by the out-of-cabin alarm means. The gist is to include.

  As described above, when an alarm is issued by the out-of-cabin alarm means when an abnormality is detected in the tire pressure, an alarm is issued even in a situation where there is little possibility that the tire will burst. There is a fear. However, an alarm in such a situation is not preferable because it becomes an excessive warning and may cause pedestrian confusion. In this regard, according to the above configuration, since the alarm is issued from the outside alarm means only when the tire may reach a burst, it is possible to obtain a necessary and sufficient warning effect while avoiding pedestrian confusion. become able to.

  According to a fourth aspect of the present invention, in the tire pressure monitoring system according to any one of the first to third aspects, the outside alarm means is a pseudo sound that is provided in a vehicle and emits a sound similar to an object. The gist of the present invention is that the alarm device is configured to issue a voice notification that the tire is abnormal through the pseudo sound generator.

  For example, if the tires are abnormal, for example, if the horn of the vehicle is only squeezed, the pedestrian around the vehicle will not recognize that it is an alarm and the horn is struck by the driver's operation. There is a risk. For this reason, there is a possibility that a pedestrian cannot be appropriately notified of tire abnormality. In this regard, as in the above configuration, if a notification is given by voice that an abnormality has occurred in the tire through the pseudo sound generation device, the pedestrian can surely recognize the abnormality of the tire. It becomes easier to take actions such as leaving. Therefore, a more reliable warning effect can be obtained.

  According to the tire pressure monitoring system of the present invention, it is possible to prevent a burst of tire fragments from coming into contact with a pedestrian.

The block diagram which shows the system configuration | structure about 1st Embodiment of the tire pressure monitoring system concerning this invention. The figure which shows typically the information memorize | stored in the non-volatile memory of the monitoring control part about the tire pressure monitoring system of the said 1st Embodiment. The flowchart which shows the process sequence about the alarm process by the tire pressure monitoring system of the said 1st Embodiment. The block diagram which shows the system configuration | structure of the remote keyless entry system of a vehicle. The block diagram which shows the system configuration | structure about 2nd Embodiment of the tire pressure monitoring system concerning this invention. The graph for demonstrating the method to detect the burst of the tire by the tire pressure monitoring system of the said 2nd Embodiment, and the method to detect the slight abnormality of the tire pressure. The flowchart which shows the procedure about the tire abnormality detection process by the tire pressure monitoring system of the said 2nd Embodiment. The figure which shows typically the information memorize | stored in the non-volatile memory of the monitoring control part about the tire pressure monitoring system of the said 2nd Embodiment. The flowchart which shows the procedure about the alarm process by the tire pressure monitoring system of the said 2nd Embodiment. The flowchart which shows the procedure about the warning process at the time of boarding / alighting by the tire pressure monitoring system of the said 2nd Embodiment.

<First Embodiment>
A tire air pressure monitoring system according to a first embodiment of the present invention will be described below with reference to FIGS. First, an outline of a tire pressure monitoring system according to the present embodiment will be described with reference to FIG. In FIG. 1, W1 represents the right front wheel of the vehicle, W2 represents the left front wheel of the vehicle, W3 represents the right rear wheel of the vehicle, and W4 represents the left rear wheel of the vehicle.

  As shown in FIG. 1, this tire pressure monitoring system is mainly configured by sensor units U1 to U4 provided on the wheels W1 to W4 to detect tire pressure, and wireless communication between these sensor units U1 to U4. And a monitoring device 1 for monitoring the tire air pressure of each of the wheels W1 to W4.

  Among these, the sensor unit U1 includes a transmitter 20 that transmits a radio signal to the monitoring device 1 and an air pressure that detects the tire air pressure of the wheel W1, as shown in a region surrounded by a two-dot chain line in the figure. A sensor 21 is provided. And the output of the air pressure sensor 21 is taken in the sensor control part 22 similarly provided in the sensor unit U1. The sensor control unit 22 detects the tire air pressure at a predetermined cycle through the air pressure sensor 21, and the detected tire air pressure information and the identification code unique to the sensor unit U1 stored in the built-in nonvolatile memory 22a. (ID code) A radio signal including ID1 is generated. The sensor control unit 22 transmits the generated wireless signal from the transmission unit 20 with a predetermined period.

  Further, the sensor units U2 to U4 have the same configuration as the sensor unit U1. However, the unique identification codes ID2 to ID4 are stored in the nonvolatile memories mounted on the sensor units U2 to U4, respectively. The sensor units U2 to U4 also transmit information on tire air pressure and a radio signal including an identification code with a predetermined period.

  On the other hand, the monitoring device 1 displays a warning when an abnormality in air pressure occurs in the tire of one of the wheels W1 to W4 and the receiving unit 10 that receives radio signals transmitted from the sensor units U1 to U4. A display unit 11 is provided. The display unit 11 is provided, for example, on an instrument panel of a vehicle. The wireless signal received via the receiving unit 10 is taken into the monitoring control unit 12 provided in the monitoring device 1. The monitoring control unit 12 is configured around an electronic control unit (ECU) having a nonvolatile memory 12a and the like, and is a part that performs processing for monitoring tire air pressure. That is, when a radio signal is input from the receiving unit 10, the monitoring control unit 12 first collates the identification code included in the radio signal with the identification code stored in the nonvolatile memory 12a. Incidentally, in the non-volatile memory 12a, as shown in FIG. 2, the positions of the wheels W1 to W4 and the identification codes of the sensor units U1 to U4 are stored in advance in association with each other. When the monitoring control unit 12 determines that the identification codes match with each other through the verification, the air pressure information included in the received radio signal indicates the tire air pressure of each of the wheels W1 to W4. Judge that it is. The monitoring control unit 12 acquires information on the tire air pressure of each wheel W1 to W4 based on such a determination method, and the acquired tire air pressure of each wheel W1 to W4 and a predetermined determination value. Based on the comparison, it is determined whether or not an abnormality has occurred in the tire air pressure of each of the wheels W1 to W4. Specifically, if the air pressure of any one of the wheels W1 to W4 is equal to or higher than a predetermined high pressure determination value or less than the low pressure determination value, an abnormality has occurred in the tire air pressure. Is determined. When the monitoring control unit 12 determines that an abnormality has occurred in the tire air pressure, the monitoring control unit 12 displays a warning through the display unit 11.

  On the other hand, as shown in FIG. 1, the vehicle is provided with a vehicle speed sensor 13 for detecting the speed of the vehicle. The output of the vehicle speed sensor 13 is taken into the monitoring control unit 12, and the monitoring control unit 12 determines whether or not the vehicle is traveling at a low speed based on the vehicle speed detected through the vehicle speed sensor 13. to decide. Here, when the monitoring control unit 12 determines that an abnormality has occurred in the tire air pressure, the sound of the horn 14 provided on the vehicle and the hazard lamp are provided on the condition that the vehicle is traveling at a low speed. By flashing 15, a warning is given to pedestrians around the vehicle.

  FIG. 3 is a flowchart showing the procedure of such alarm processing executed through the monitoring control unit 12. Hereinafter, the specific procedure of the processing will be summarized based on FIG. This process is executed when a radio signal transmitted from the sensor units U1 to U4 is received.

  As shown in FIG. 3, in this process, first, it is determined whether or not the identification code included in the wireless signal matches the identification code stored in the nonvolatile memory 12a (step S1). If it is determined that the identification codes match each other (step S1: YES), it is determined whether or not an abnormality has occurred in the tire air pressure as the processing of the subsequent step S2. In the process of step S2, as described above, when the value of the tire air pressure included in the radio signal is equal to or higher than the high pressure determination value or less than the low pressure determination value, an abnormality has occurred in the tire air pressure. It is determined. If it is determined that there is an abnormality in the tire air pressure (step S2: YES), whether or not the vehicle is traveling at a low speed based on the vehicle speed detected through the vehicle speed sensor 13 is determined. Is determined (step S3). Specifically, when the low speed determination value is Vth, it is determined that the vehicle is traveling at a low speed when the vehicle speed V satisfies a condition “0 <V ≦ Vth”, for example. Note that the value of the low speed determination value Vth is set to 20 kilometers per hour, for example, and is stored in advance in the nonvolatile memory 12a. When it is determined that the vehicle is not traveling at low speed (step S3: NO), a warning is displayed through the display unit 11 (step S5), and the monitoring control unit 12 performs this series of processing. finish.

  On the other hand, when it is determined that the vehicle is traveling at a low speed (step S3: YES), the horn 14 is sounded and the hazard lamp 15 is blinked for a predetermined time (step S4). Further, warning processing is performed through the display unit 11 as the processing of the subsequent step S5, and the monitoring control unit 12 ends this series of processing.

  When the identification code included in the wireless signal does not match the identification code stored in the nonvolatile memory 12a (step S1: NO), or when it is determined that there is no abnormality in the tire air pressure. (Step S2: NO), the monitoring control unit 12 ends this series of processing.

Next, the operation and action of the tire pressure monitoring system having such a configuration will be described.
In the tire pressure monitoring system of the present embodiment, if an abnormality occurs in the tire pressure while the vehicle is traveling at a low speed, the horn 14 sounds or the hazard lamp 15 flashes to alert the outside of the passenger compartment. It is done. Therefore, pedestrians around the vehicle can recognize an abnormality in tire air pressure through these warnings, and can take avoidance actions such as leaving the vehicle before the tire reaches a burst. For this reason, it is possible to prevent the burst tire fragments from coming into contact with the pedestrian.

  In addition, when the user runs the vehicle while leaving the state where the tire air pressure is abnormal, the horn 14 and the hazard lamp 15 are periodically blinked. I think it feels. Therefore, since the user is forced to perform an operation of adjusting the tire air pressure to an appropriate value, the tire burst can be avoided in advance.

  On the other hand, in a situation where the vehicle is traveling at a high speed, even if the horn 14 sounds or the hazard lamp 15 blinks, it is difficult for the pedestrian to immediately take an action such as leaving the vehicle. Not only is it not effective, but such warnings can cause pedestrian confusion. Therefore, if the horn 14 is sounded or the hazard lamp 15 is blinked only when the vehicle is traveling at a low speed, a sufficient warning effect can be obtained while avoiding the pedestrian confusion. become.

As described above, according to the tire pressure monitoring system according to the present embodiment, the following effects can be obtained.
(1) When an abnormality is detected in the tire air pressure, an alarm is issued outside the passenger compartment. This makes it possible for pedestrians around the vehicle to take avoidance actions such as leaving the vehicle before the tire reaches the burst, so that the burst of tire fragments will contact the pedestrian in advance. Can be prevented.

  (2) The condition for issuing an alarm outside the passenger compartment includes that the vehicle speed is lower than a preset low speed determination value Vth. As a result, a sufficient warning effect can be obtained while avoiding pedestrian confusion.

  (3) The alarm to the outside of the passenger compartment is performed by sounding the horn 14 and blinking the hazard lamp 15. As a result, it is possible to accurately warn pedestrians around the vehicle. In addition, since it is not necessary to newly provide a device for alarming outside the passenger compartment, the cost can be reduced.

<Second Embodiment>
Next, a second embodiment of the tire pressure monitoring system according to the present invention will be described with reference to FIGS. It is assumed that the vehicle to which the tire pressure monitoring system of the present embodiment is applied is a vehicle that uses an electric motor (motor) as a drive source, such as a hybrid vehicle or an electric vehicle. Further, it is assumed that this vehicle is equipped with a so-called remote keyless entry (RKE) system that can remotely control locking and unlocking of a vehicle door by operating a switch provided in a portable device. Hereinafter, the difference from the first embodiment will be mainly described.

  As in the first embodiment, when an alarm is issued to the outside of the passenger compartment when an abnormality occurs in the tire air pressure, there is almost no possibility that the tire will burst. An alarm may be issued. However, the warning in such a situation becomes an excessive warning and may cause pedestrian confusion. Therefore, in the present embodiment, it is determined whether or not there is a possibility that the tire reaches a burst based on the air pressure and the internal temperature of the tire. When there is a possibility that the tire may burst, an alarm is issued to the outside of the passenger compartment on the condition that the vehicle is traveling at a low speed. In the present embodiment, the RKE system is used to detect the user's getting on and getting off, and also when there is a possibility that the tire may burst when the user gets on and getting off, an alarm is given to the outside of the passenger compartment. To emit.

FIG. 4 is a block diagram showing the system configuration of the RKE system. First, the RKE system will be described.
As shown in FIG. 4, the RKE system is mainly composed of a portable device 30 possessed by a user and an in-vehicle device 40 provided in the vehicle.

  Here, the portable device 30 is provided with a lock switch 31 that is operated when the vehicle door is locked, and an unlock switch 32 that is operated when the vehicle door is unlocked. The portable device 30 wirelessly transmits a lock command signal when the lock switch 31 is turned on by the user. Further, when the unlock switch 32 is turned on by the user, an unlock command signal is wirelessly transmitted.

  On the other hand, the in-vehicle device 40 is provided with a receiving unit 41 that receives a lock command signal and an unlock command signal transmitted from the portable device 30. When receiving the command signals, the receiving unit 41 transmits the received command signals to the RKE control unit 42 provided in the in-vehicle device 40. The RKE control unit 42 is configured around the ECU, and is a part that performs various processes related to the RKE system in an integrated manner. That is, when the lock command signal is transmitted from the receiving unit 41, the RKE control unit 42 locks the vehicle door through the door lock mechanism 43 that is a control target. Further, when an unlock command signal is transmitted from the receiving unit 41, the vehicle door is unlocked through the door lock mechanism 43. Further, the RKE control unit 42 is connected to the monitoring control unit 12 via the communication bus 16 constituting a bus-type in-vehicle network system such as a CAN (Controller Area Network), for example. Various data are exchanged with the monitoring control unit 12. Specifically, when the vehicle door is locked and unlocked based on the lock command signal and the unlock command signal, the fact is transmitted to the monitoring control unit 12 via the communication bus 16. Here, when a signal indicating that the vehicle door is locked is transmitted from the RKE control unit 42, the monitoring control unit 12 determines that the user has got off the vehicle. Further, when a signal indicating that the vehicle door is unlocked is transmitted from the RKE control unit 42, it is determined that the user is about to get on.

  Next, the system configuration of the tire pressure monitoring system according to the present embodiment will be described with reference to FIG. The basic configuration of the tire pressure monitoring system of the present embodiment is similar to the configuration illustrated in FIG. 1, and here, the system configuration of the tire pressure monitoring system is shown as a diagram corresponding to FIG. As shown in FIG.

  As shown in the area surrounded by the two-dot chain line in FIG. 5, the sensor unit U1 is provided with a temperature sensor 23 for detecting the internal temperature of the tire. And the sensor control part 22 detects the internal temperature of a tire with a predetermined period through this temperature sensor 23. The sensor control unit 22 calculates the amount of change in air pressure per unit time from the time-series data each time the tire air pressure is detected through the air pressure sensor 21. And when the sensor control part 22 produces | generates a radio signal, the internal temperature of a tire and the information of the variation | change_quantity of the air pressure per unit time are also included in a radio signal. That is, the sensor unit U1 transmits a wireless signal including the tire air pressure, the amount of change in air pressure per unit time, the tire internal temperature, and the identification code ID1 with a predetermined period.

  The sensor units U2 to U4 also have the same configuration as the sensor unit U1. That is, the sensor units U1 to U4 also transmit wireless signals including tire air pressure, change amount of tire air pressure per unit time, tire internal temperature, and identification code at predetermined intervals, respectively.

  On the other hand, when the monitoring control unit 12 receives wireless signals transmitted from the sensor units U1 to U4, the air pressure of the tires of the wheels W1 to W4 and the amount of change in air pressure per unit time through the above-described verification of the identification codes. And information on the internal temperature. Further, based on the acquired tire state quantities of the wheels W1 to W4, it is determined whether or not there is an abnormality in the tire air pressure and whether or not there is a possibility that the tire will burst. Specifically, as shown in FIG. 6, regarding the tire air pressure P of each of the wheels W1 to W4, in addition to the low pressure determination value Pth1 and the high pressure determination value Pth2, whether the tire may reach a burst or not. Two determination values Pth3 and Pth4 are set in advance as determination values for determining whether or not. That is, a low-pressure burst determination value Pth3 lower than the low-pressure determination value Pth1 and a high-pressure burst determination value Pth4 higher than the high-pressure determination value Pth2 are set. On the other hand, as for the internal temperature T of the tire, a high temperature determination value Tth is set in advance. Then, the monitoring control unit 12 determines the tire state based on the comparison between the tire pressure P and the internal temperature T of the wheels W1 to W4 and the determination values Pth1 to Pth4 and Tth (a1) to ( Determine as shown in a6).

(A1) When the tire air pressure P satisfies the condition of “P <Pth3” as indicated by the region A in the drawing. In this case, it is determined that the tire may reach a burst.
(A2) When the air pressure P of the tire satisfies the condition “Pth3 ≦ P <Pth1” as indicated by the region B in the drawing. In this case, there is no possibility that the tire will burst, but it is determined that a slight abnormality has occurred in the tire air pressure.

  (A3) When the tire air pressure P satisfies the condition of “Pth1 ≦ P <Pth2” as indicated by region C in the drawing. In this case, it is determined that there is no abnormality in the tire air pressure.

  (A4) When the tire air pressure P satisfies the condition “Pth2 ≦ P <Pth4” and the tire internal temperature T satisfies the condition “T <Tth”, as indicated by the region D in the drawing. . In this case, there is no possibility that the tire will burst, but it is determined that a slight abnormality has occurred in the tire air pressure.

  (A5) As indicated by region E in the figure, the tire air pressure P satisfies the condition “Pth2 ≦ P <Pth4” and the tire internal temperature T satisfies the condition “Tth ≦ T”. If. In this case, it is determined that the tire may reach a burst.

(A6) When the internal temperature T of the tire satisfies the condition “T <Tth” as indicated by the region F in the drawing. In this case, it is determined that the tire may reach a burst.
On the other hand, regarding the amount of change in air pressure per unit time, a sudden decrease determination value (<0) is set in advance. And the monitoring control part 12 determines the state of a tire as shown to the following (a7) based on the comparison with the variation | change_quantity of the air pressure per unit time, and a sudden decrease determination value.

(A7) The amount of change in air pressure per unit time is equal to or less than the sudden decrease determination value. In this case, it is determined that the tire may reach a burst.
Then, when any tire of each of the wheels W1 to W4 may reach a burst, the monitoring control unit 12 issues an alarm outside the passenger compartment on the condition that the vehicle is traveling at a low speed. Here, in the present embodiment, as shown in FIG. 5 above, an alarm is generated outside the passenger compartment using the pseudo sound generating device 17 provided in the vehicle. The pseudo sound generator 17 emits a pre-recorded engine sound or the like from a speaker so as to notify a pedestrian of the approach of the vehicle when the vehicle is driven by the power of an electric motor. In addition, an arbitrary sound similar to the object such as an artificial voice can be emitted. When there is a possibility that the tire may reach a burst, the monitoring control unit 12 issues a warning to the outside of the passenger compartment by notifying the fact from the pseudo sound generating device 17 by sound. Further, the monitoring control unit 12 can monitor the user's getting on and getting off based on the information transmitted from the RKE control unit 42, and the tires of the wheels W1 to W4 can reach a burst when the user gets on and off. Even if there is a possibility, an alarm is issued from the pseudo sound generator 17.

  FIG. 7 is a flowchart showing a procedure of processing for detecting an abnormality in tire air pressure, which is executed through the monitoring control unit 12. This process is executed when radio signals transmitted from the sensor units U1 to U4 are received. The flags F11 to F14 and F21 to F24 described below are set to “0” as their initial values.

  As shown in FIG. 7, in this process, first, it is determined whether or not the identification code included in the wireless signal matches the identification code stored in the nonvolatile memory 12a (step S10). When it is determined that the identification codes match each other (step S10: YES), it is determined whether there is a possibility that the tire may reach a burst (step S11). In the process of step S11, specifically, the above (a1), (a5) to (a7) are based on the tire air pressure, the amount of change in air pressure per unit time, and the internal temperature information included in the radio signal. When it is determined that any one of the conditions is satisfied, it is determined that the tire may reach a burst. Then, when there is a possibility that the tire may reach a burst (step S11: YES), as shown in FIG. 8, the verification is performed among the burst determination flags F11 to F14 corresponding to the identification codes ID1 to ID4. The value of the flag corresponding to the identification code is set to “1” (step S12), and the monitoring control unit 12 ends this series of processing.

  On the other hand, as shown in FIG. 7, when there is no possibility that the tire will burst (step S11: NO), it is determined whether or not a slight abnormality has occurred in the tire air pressure as the processing of the subsequent step S13. Is done. In the process of step S13, specifically, any one of the above conditions (a2) and (a4) is satisfied based on the tire air pressure P and the internal temperature T included in the radio signal. When it is determined that there is a slight abnormality, it is determined that a slight abnormality has occurred in the tire air pressure. When it is determined that a slight abnormality has occurred in the tire air pressure (step S13: YES), as shown in FIG. 8, the air pressure abnormality determination flags F21 to F21 corresponding to the respective identification codes ID1 to ID4. In F24, the value of the flag corresponding to the identified identification code is set to “1” (step S14), and the monitoring control unit 12 ends this series of processing.

  On the other hand, when it is determined that no minor abnormality has occurred in the tire air pressure (step S13: NO), burst determination flags F11 to F14 and air pressure abnormality determination flag F21 corresponding to the respective identification codes ID1 to ID4. The values of the flags corresponding to the identification codes that have been collated among -F24 are set to "0" (step S15). And the monitoring control part 12 complete | finishes this series of processes, after performing the process of step S15.

  When it is determined that the identification code included in the wireless signal does not match the identification code stored in the nonvolatile memory 12a (step S10: NO), the monitoring control unit 12 ends this series of processing. To do.

  Next, with reference to FIG. 9, alarm processing executed through the monitoring control unit 12 will be described. Note that the process shown in FIG. 9 is repeatedly executed with a predetermined cycle when, for example, the ignition switch of the vehicle is on.

  As shown in FIG. 7, in this process, it is first determined whether or not the vehicle is traveling at a low speed (step S20). When it is determined that the vehicle is traveling at a low speed (step S20: YES), it is determined whether any of the burst determination flags F11 to F14 is set to “1”. (Step S21). Here, when it is determined that any one of the burst determination flags F11 to F14 is set to “1” (step S21: YES), a sound alarm is given through the pseudo sound generator 17 in advance. Only time is executed (step S22). Further, a warning is displayed through the display unit 11 (step S23), and the monitoring control unit 12 once ends this series of processing.

  On the other hand, when it is determined that all the values of the burst determination flags F11 to F14 are not set to “1” (step S21: NO), the air pressure abnormality determination flags F21 to F24 are processed as the subsequent step S24. It is determined whether or not any of these values is set to “1” (step S24). Here, when it is determined that one of the values of the air pressure abnormality determination flags F21 to F24 is set to “1” (step S24: YES), a warning is displayed through the display unit 11 ( In step S23), the monitoring controller 12 once ends this series of processing.

  On the other hand, when it is determined that the vehicle is not traveling at a low speed (step S20: NO), it is determined that all the values of the air pressure abnormality determination flags F21 to F24 are not set to “1”. In this case (step S24: NO), the monitoring control unit 12 once ends this series of processing.

  Next, with reference to FIG. 10, processing for issuing an alarm when the user gets on and off the vehicle, which is executed through the monitoring control unit 12, will be described. This process is executed when a signal indicating that the vehicle door is locked or a signal indicating that the vehicle door is unlocked is transmitted from the RKE control unit 42.

  As shown in FIG. 10, in this process, first, it is determined whether or not any value of the burst determination flags F11 to F14 is set to “1” (step S30). Here, when it is determined that any one of the burst determination flags F11 to F14 is set to “1” (step S30: YES), a warning is given by voice through the pseudo-sound generator 17 described above. It is issued only for a time (step S31).

  On the other hand, when it is determined that all the values of the burst determination flags F11 to F14 are not set to “1” (step S30: NO), the monitoring control unit 12 ends this series of processes.

Next, the operation and action of the tire pressure monitoring system having such a configuration will be described.
In the tire pressure monitoring system according to the present embodiment, when the vehicle is traveling at a low speed, only when there is a possibility that any of the tires of each of the wheels W1 to W4 may reach a burst, the pseudo sound generating device 17 performs the outside of the passenger compartment. An alarm is issued. As a result, a sufficient warning effect can be obtained while avoiding pedestrian confusion.

  By the way, as in the case of the first embodiment, when the tires may reach a burst, the horns of the vehicle and the hazard lamps 15 are simply turned on to alert pedestrians around the vehicle. Without recognizing, there is a risk of misunderstanding that the horn 14 is ringing by the driver's operation. For this reason, there is a possibility that a pedestrian cannot be properly notified of an abnormality in tire air pressure. In this regard, in the present embodiment, when there is a possibility that any of the tires of each of the wheels W1 to W4 may reach a burst, the fact is notified by voice through the pseudo sound generation device 17, so It is possible to reliably recognize that the tire may reach a burst. For this reason, since it becomes easy for a pedestrian to take action, such as leaving | separating from a vehicle, a more reliable warning effect can be acquired now.

  In addition, when the user gets on and off the vehicle, if there is a possibility that the tire may burst, an alarm is issued from the pseudo sound generator 17 to the outside of the passenger compartment, so the user may possibly burst the tire. I can know that. For this reason, since the user can take measures for avoiding the burst, such as adjusting the air pressure of the tire to an appropriate air pressure before driving the vehicle, high safety can be ensured.

  As described above, according to the tire pressure monitoring system according to the present embodiment, effects similar to or equivalent to the effects (1) and (2) according to the first embodiment can be obtained. The effect like this comes to get.

(4) When there is a possibility that the tire may burst, an alarm is given to the outside of the passenger compartment. This makes it possible to obtain a sufficient warning effect while avoiding pedestrian confusion.
(5) The detection of whether or not there is a possibility that the tire may reach a burst is made by comparing the tire state quantity detected through the sensor units U1 to U4 with each of the determination values Pth1 to Pth4, Tth and the sudden decrease determination value. Based on that. As a result, it is possible to easily detect whether or not there is a possibility of the tire reaching a burst.

  (6) A warning to the outside of the passenger compartment is given by notifying the pseudo-sound generator 17 by voice that the tire may reach a burst. Thereby, since the pedestrian around a vehicle can recognize reliably that a tire may reach a burst, a warning effect can be obtained more reliably. In addition, since it is not necessary to newly provide a device for alarming outside the passenger compartment, the cost can be reduced.

  (7) When there is a possibility that the tire may burst when the vehicle user gets on and off the vehicle, an alarm is given to the outside of the passenger compartment. As a result, the user can take measures to avoid the burst, such as adjusting the tire air pressure to an appropriate air pressure before driving the vehicle, so that high safety can be ensured.

<Other embodiments>
In addition, each said embodiment can also be implemented with the following forms which changed this suitably.
In the first embodiment, the horn 14 and the hazard lamp 15 are used as the vehicle exterior alarm means for issuing an alarm outside the vehicle compartment. Instead, for example, a vehicle headlamp or a pseudo sound generator is used. Etc. may be used. When using a headlamp, an alarm is given to the outside of the passenger compartment by turning on the lamp. In addition, a device for issuing an alarm outside the passenger compartment may be newly provided in the vehicle. Similarly, in the second embodiment, for example, the horn 14 or the hazard lamp 15 may be used instead of the pseudo sound generator 17.

  In the second embodiment, the warning is given to the outside of the passenger compartment when there is a possibility that the tire may burst when the user of the vehicle gets on and off the vehicle. However, this configuration can be omitted. is there.

  In the second embodiment, the detection of getting on and off of the user of the vehicle is performed using the RKE system, but may be performed using a smart entry system of the vehicle, for example. Incidentally, the smart entry system, for example, when a portable device enters a communication area set around the vehicle, performs bidirectional wireless communication between the portable device and the vehicle-mounted device to lock and unlock the vehicle door. This is a system for locking. In this case, for example, when it is detected that the portable device has entered a communication area set around the vehicle, it is determined that the user is about to get on. When it is detected that the portable device has left the communication area, it is determined that the user has got off the vehicle. In addition to the method of using these RKE system and smart entry system, the user's boarding and getting off may be detected by an appropriate method.

In the second embodiment, the RKE control unit 42 and the monitoring control unit 12 are configured by separate ECUs, but may be configured by a single ECU.
In the second embodiment, a warning is given to the outside of the passenger compartment by generating a sound from the pseudo sound generating device 17, but an appropriate electronic sound is generated from an electronic sound generating device mounted on the vehicle, for example. You may give a warning outside the car. As the electronic sound generating device, for example, a device that emits a beep (electronic sound) when the vehicle door is unlocked can be used. In this case, an effective warning can be given to pedestrians around the vehicle by using an electronic sound that is different from the electronic sound emitted when the vehicle door is unlocked. it can.

  In each of the above embodiments, the alarm is given to the outside of the passenger compartment on the condition that the vehicle is traveling at a low speed. For example, when the vehicle is traveling at a high speed, an alarm is given to the outside of the passenger compartment. Also good. In short, any alarm may be used as long as the vehicle is running when an abnormality is detected in the tire air pressure.

<Appendix>
Next, a technical idea that can be grasped from the above embodiment and its modifications will be additionally described.
(A) In the tire air pressure monitoring system according to claim 3, the tire air pressure abnormality is detected on condition that the air pressure detected through the sensor unit is equal to or higher than a high pressure judgment value. Detection of the possibility of reaching a burst is performed based on a comparison between a tire air pressure detected through the sensor unit and a high-pressure-side burst determination value higher than the high-pressure determination value. Air pressure monitoring system. According to this configuration, it is possible to easily detect whether or not there is a possibility that the tire will reach a burst.

  (B) In the tire air pressure monitoring system according to claim 3, the tire air pressure abnormality is detected on condition that the air pressure detected through the sensor unit is equal to or higher than a high pressure judgment value. Detection of the possibility of a burst is based on a comparison between the tire air pressure detected through the sensor unit and the high pressure determination value, and a comparison between the temperature detected through the sensor unit and the high temperature determination value. Tire pressure monitoring system characterized by being performed. According to this configuration, it is possible to easily detect whether or not there is a possibility that the tire will reach a burst.

  (C) In the tire air pressure monitoring system according to claim 3, the tire air pressure abnormality is detected on condition that the air pressure detected through the sensor unit is less than a low pressure judgment value. Detection of the possibility of a burst being made based on a comparison between a tire air pressure detected through the sensor unit and a low-pressure-side burst determination value lower than the low-pressure determination value Air pressure monitoring system. According to this configuration, it is possible to easily detect whether or not there is a possibility that the tire will reach a burst.

  (D) In the tire pressure monitoring system according to claim 3, the detection that the tire may reach a burst is a change amount per unit time of the tire pressure detected through the sensor unit, A tire pressure monitoring system, which is performed based on a comparison with a predetermined sudden decrease determination value. According to this configuration, it is possible to easily detect whether or not there is a possibility that the tire will reach a burst.

  (E) In the tire air pressure monitoring system according to any one of claims 1 to 3, the vehicle exterior alarm means is a horn provided in a vehicle, and issues an alarm by sounding the horn. Tire pressure monitoring system characterized by that. According to this configuration, it is possible to accurately warn pedestrians around the vehicle.

  (F) The tire pressure monitoring system according to any one of claims 1 to 3, wherein the vehicle exterior alarm means is a hazard lamp provided in a vehicle, and issues an alarm by blinking the hazard lamp. A tire pressure monitoring system characterized by being. According to this configuration, it is possible to accurately warn pedestrians around the vehicle.

  (G) The tire pressure monitoring system according to any one of claims 1 to 3, wherein the vehicle exterior alarm means is a headlight provided in a vehicle, and issues an alarm by turning on the headlight. A tire pressure monitoring system characterized by being. According to this configuration, it is possible to accurately warn pedestrians around the vehicle.

  (H) In the tire air pressure monitoring system according to any one of claims 1 to 4 and appendices (i) to (d), as a condition for issuing an alarm by the out-of-cabin alarm means, the user of the vehicle gets on or off the vehicle The tire pressure monitoring system further comprising detecting the air pressure. According to this configuration, when the user gets on and off the vehicle, if there is an abnormality in the tire air pressure, an alarm is issued by the outside alarm means, so that the user recognizes the tire air pressure abnormality. Can do. For this reason, since the user can take measures for avoiding the burst, such as adjusting the air pressure of the tire to an appropriate air pressure before driving the vehicle, high safety can be ensured.

  U1 to U4 ... sensor unit, W1 ... right front wheel, W2 ... left front wheel, W3 ... right rear wheel, W4 ... left rear wheel, 1 ... monitoring device, 10 ... receiving unit, 11 ... display unit, 12 ... monitoring control unit, DESCRIPTION OF SYMBOLS 12a ... Nonvolatile memory, 13 ... Vehicle speed sensor, 14 ... Horn, 15 ... Hazard lamp, 16 ... Communication bus, 17 ... Pseudo sound generator, 20 ... Transmission part, 21 ... Air pressure sensor, 22 ... Sensor control part, 22a ... Non-volatile memory, 23 ... temperature sensor, 30 ... portable device, 31 ... lock switch, 32 ... unlock switch, 40 ... in-vehicle device, 41 ... receiving unit, 42 ... RKE control unit, 43 ... door lock mechanism.

Claims (4)

When the air pressure of the tire mounted on the wheel is detected through a sensor unit provided on the wheel of the vehicle, and when an abnormality is detected in the tire air pressure detected through the sensor unit, the alarm means provided on the vehicle is used. In the tire pressure monitoring system that issues an alarm,
The vehicle is provided with an out-of-cabin alarm unit that issues an alarm outside the vehicle compartment as the alarm unit, and when an abnormality is detected in the tire air pressure detected through the sensor unit, the vehicle is on the condition that the vehicle is running. A tire pressure monitoring system characterized by issuing an alarm by an alarm means. The tire pressure monitoring system according to claim 1, further comprising, as a condition for issuing an alarm by the outside alarm means, that the speed of the vehicle is lower than a preset low speed judgment value. The tire pressure monitoring system according to claim 1 or 2, further comprising the possibility that the tire reaches a burst as a condition for issuing an alarm by the vehicle exterior alarm means. In the tire pressure monitoring system according to any one of claims 1 to 3,
The out-of-cabin alarm means is a pseudo sound generating device that is provided in a vehicle and emits a sound similar to an object, and issues a warning by notifying the tire that the tire is abnormal through the pseudo sound generating device. Tire pressure monitoring system characterized by that.

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