JP2014034797A - Integrated receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an integrated receiver which monitors the air pressure of a tire even if reception of a radio wave of an electronic key system and reception of a radio wave of a tire air pressure monitor system overlap with each other.SOLUTION: A vehicle 12 includes a UHF reception part 45 which receives a radio signal, including air pressure information on each tire 13, from a sensor unit 14 provided for each tire 13 and a radio signal from an electronic key 52. The UHF reception part 45 is connected to a first changeover switch 43. The first changeover switch 43 connects the UHF reception part 45 selectively to a TPMSECU 31 which monitors the air pressure of the tire, and a matching ECU 41 which performs ID matching with the electronic key 52. The first changeover switch 43 connects the UHF reception part 45 to the TPMSECU 31 when a period in which the UHF reception part 45 is connected to the TPMSECU 31 and a period in which the UHF reception part 45 is connected to the matching ECU 41 overlap with each other.

Description

  The present invention relates to an integrated receiver that receives both a radio wave of a tire pressure monitoring system and a radio wave of an electronic key system.

  Conventionally, a tire pressure monitoring system for monitoring the tire pressure of a vehicle disclosed in Patent Document 1 is known. The system includes a sensor unit with a wireless communication function provided in each tire of a vehicle. This sensor unit detects the air pressure of the tire and transmits a radio signal including the detected air pressure information and identification information unique to itself. This radio signal is received by a monitoring device provided in the main body of the vehicle. In the apparatus, the identification information of each sensor unit is registered in advance in a state in which it is associated with the mounting position (left front, left rear, right front, right rear) of each tire. Then, the device determines which of the tires the air pressure information included in the wireless signal is based on the identification information included in the received wireless signal, and determines the air pressure of each tire based on the air pressure information. Monitor for abnormalities. When it is determined that any one of the tires has an abnormal air pressure, the device warns that through a display device in the passenger compartment. The driver can recognize which of the tires is abnormal through the warning.

  On the other hand, many vehicles including Patent Document 1 are equipped with an electronic key system that authenticates an electronic key by wireless communication with the electronic key. In an electronic key system, for example, ID collation (smart collation) is performed by narrow-band radio in response to communication from a vehicle, and the door can be locked and unlocked and the engine can be started without performing a key operation.

  By the way, in the case of the current system, the radio wave transmitted from the electronic key and the radio wave transmitted from the tire pressure sensor are both UHF (Ultra High Frequency) band radio waves. Therefore, in Patent Document 1, a receiver mounted on the vehicle body is used as a common receiver (integrated receiver) for the electronic key system and the tire pressure monitoring system with the aim of reducing the number of parts of the vehicle.

Japanese Patent No. 4552959

  By the way, if the reception timing of the radio signal transmitted from the tire and the reception timing of the radio signal transmitted from the electronic key overlap, the integrated receiver cannot determine the radio signal from which the received radio signal is. The wireless signal cannot be processed.

  The present invention has been made in view of such a situation, and an object of the present invention is to monitor tire air pressure even when radio wave reception timing of an electronic key system overlaps with radio wave reception timing of a tire air pressure monitoring system. It is to provide an integrated receiver.

  In order to solve the above problems, the invention of claim 1 is transmitted from a tire pressure monitoring system for monitoring tire pressure through a wireless signal including tire pressure information from a sensor unit provided in each tire and an electronic key. In the integrated receiver for receiving the radio signal in both the system and the electronic key system for checking the radio signal, the first mode for receiving the radio signal from the electronic key and the second mode for receiving the radio signal from the sensor unit When the period for the first mode and the period for the second mode overlap, the gist is to set the second mode.

  According to this configuration, the integrated receiver receives the wireless signal from the sensor unit with priority when the reception timing of the wireless signal from the electronic key and the reception timing of the wireless signal from the sensor unit overlap. can do. Thereby, the integrated receiver can monitor the tire pressure.

  According to a second aspect of the present invention, in the integrated receiver according to the first aspect, the monitoring control unit that controls the tire pressure monitoring system and the verification control unit that controls the electronic key system are selectively connected. The first changeover switch is connected to the monitoring control unit when the period for the first mode and the period for the second mode overlap.

  According to the same configuration, the monitoring control unit and the integrated receiver are connected to each other when the period of the first mode and the period of the second mode overlap with the simple configuration of the first changeover switch. Only by switching to, the monitoring control unit can monitor the tire pressure.

  The invention according to claim 3 is the integrated receiver according to claim 1 or 2, wherein the integrated receiver has a third mode in which radio signals from the electronic key and the sensor unit are not received, and the first period or more In the case where the third mode is switched to the first mode in the second cycle, which is a short cycle, the first mode is switched from the third mode to the first mode in the first cycle. The gist is that after the period for the mode and the period for the second mode overlap, the mode is switched from the third mode to the first mode in the second period.

  According to this configuration, it is easy to receive the radio signal from the electronic key after receiving the radio signal from the sensor unit.

  The present invention can provide an integrated receiver that monitors tire air pressure even when the reception timing of radio waves of the electronic key system and the reception timing of radio waves of the tire pressure monitoring system overlap.

The block diagram which shows schematic structure of the tire pressure monitoring system in 1st and 2nd embodiment. The time chart which shows the standby mode and non-standby mode of a receiving part. The list figure which shows the structure of the table data memorize | stored in the memory by the side of a vehicle. The time chart which shows the state of the 1st and 2nd change-over switch. The time chart which shows the state of the 1st changeover switch in 2nd Embodiment.

[First Embodiment]
A first embodiment embodying an integrated receiver according to the present invention will be described below with reference to FIGS.

<System overview>
As shown in FIG. 1, the vehicle 12 transmits an electronic key system 51 that performs ID verification via wireless communication with the electronic key 52, and a wireless signal transmitted from a sensor unit that is provided integrally with a tire air valve. And a tire pressure monitoring system 11 for monitoring the tire pressure. The vehicle 12 includes a UHF receiver 45 as an integrated receiver that receives a radio signal transmitted from the electronic key 52 and a radio signal transmitted from the sensor unit.

<Outline of electronic key system>
First, an outline of the electronic key system 51 will be described. The electronic key system 51 includes an electronic key 52 possessed by a driver of the vehicle 12 and an in-vehicle device 40 disposed on the vehicle 12. The vehicle-mounted device 40 permits switching of the lock and unlock of the door lock and switching of the vehicle power on / off on condition that the wireless communication performed with the electronic key 52 is established.

<Electronic key>
The electronic key 52 has a wireless communication function, and controls various in-vehicle devices through mutual wireless communication with the in-vehicle device 40. The electronic key 52 includes an electronic key control unit 53 configured by a computer unit including a CPU, a ROM, a RAM, and the like, and an LF reception unit that is electrically connected to the electronic key control unit 53 and receives an LF band request signal. 54 and a UHF transmitter 55 for transmitting a response signal in the UHF band. The request signal is transmitted from the vehicle-mounted device 40, and the response signal is transmitted from the electronic key 52 in response to the request signal. These request signal and response signal include information for mutual authentication between the vehicle-mounted device 40 and the electronic key 52, respectively.

  When receiving the LF band request signal transmitted from the vehicle-mounted device 40, the LF receiver 54 demodulates the request signal into a pulse signal and outputs the demodulated demodulated signal to the electronic key controller 53.

  Information for mutual authentication with the vehicle-mounted device 40 is stored in the memory 53a of the electronic key control unit 53. When the electronic key control unit 53 recognizes that the request signal has been received, the electronic key control unit 53 determines whether or not the request signal is wirelessly transmitted from the vehicle 12 corresponding to itself from various information included in the signal. When the electronic key control unit 53 determines that the received request signal is wirelessly transmitted from the vehicle 12 corresponding to the electronic key control unit 53, the electronic key control unit 53 generates a response signal to the request signal. The UHF transmission unit 55 converts the generated response signal into a radio signal in the UHF band, and transmits this to the vehicle 12 side.

<In-vehicle device>
The vehicle-mounted device 40 includes a computer unit that includes a CPU, a ROM, a RAM, and the like. As shown in FIG. 1, the vehicle-mounted device 40 includes a verification ECU 41 as a verification control unit that controls various on-vehicle devices, and an LF transmission unit 44 that is electrically connected to the verification ECU 41 and transmits a request signal for the LF band. And a UHF receiver 45 that receives a response signal in the UHF band. The verification ECU 41 is connected to the UHF receiver 45 via the first changeover switch 43. The first changeover switch 43 is also connected to a TPMS ECU 31 described later. The first changeover switch 43 has a first connection mode in which the UHF receiver 45 and the verification ECU 41 are connected, and a second connection mode in which the UHF receiver 45 and the verification ECU 41 are connected. The first changeover switch 43 switches from the second connection mode to the first connection mode based on a first changeover signal (described later) generated by the verification ECU 41. The first changeover switch 43 switches from the first connection mode to the second connection mode based on a second switching signal generated by a TPMS ECU 31 described later.

  Further, as shown in FIG. 1, the verification ECU 41 includes a door handle sensor 47 provided on the door handle for detecting whether or not the user touches the door handle, and a door lock for automatically locking and unlocking the vehicle door. The device 48 is electrically connected. Further, an ignition switch 49 (hereinafter referred to as IGSW 49) is electrically connected to the verification ECU 41. The door handle sensor 47 generates an electrical signal indicating that the door handle sensor 47 has been touched. The IGSW 49 generates a switch signal indicating the power state of the vehicle body 15 (vehicle power on / off).

  In the memory 41a of the verification ECU 41, information for specifying the electronic key 52 corresponding to itself and information for generating random number data are stored. The verification ECU 41 generates a request signal including random number data based on the information stored in the memory 41a, and when receiving a response signal to the request signal, the response signal is stored in the electronic key 52 corresponding to itself. Judge whether or not.

  In addition, a first switching timing calculation program 46 is stored in the memory 41a of the verification ECU 41. The first changeover timing calculation program 46 changes the first changeover switch 43 from the second connection mode to the first connection mode, and also changes the second changeover switch 33 described later from OFF to ON. 1 is a program for calculating a first switching timing and a second switching timing for switching the second switch 33 from on to off.

  When generating the request signal, the verification ECU 41 calculates the first switching timing and the second switching timing based on the first switching timing calculation program 46. When the first switching timing is reached, the verification ECU 41 switches the first switching switch 43 from the second mode to the first mode, and indicates that the second switching switch 33 is switched from OFF to ON. Generate a switching signal. In addition, when the second switching timing is reached, the verification ECU 41 generates a second switching signal indicating that the second switching switch 33 is switched from on to off.

  The verification ECU 41 also has a power supply state monitoring unit 42 that monitors the power supply state. The power supply state monitoring unit 42 monitors the power supply state of the vehicle body 15 through monitoring the switch signal generated by the IGSW 49.

  When the vehicle 12 is powered off and locked, such as when the user gets on, the verification ECU 41 periodically transmits a request signal from the LF transmission unit 44 to a predetermined communication area set outside the vehicle. When the UHF receiver 45 receives a response signal to the previous request signal from the electronic key 52, it demodulates it into a pulse signal.

  When the demodulated signal of the response signal is input from the UHF receiver 45, the verification ECU 41 reads data included in the demodulated signal. Then, the verification ECU 41 performs external verification to determine the validity of the received data through comparison between the received data and the data stored in the memory 41a. When this outside vehicle collation is established, the collation ECU 41 activates the door handle sensor 47. In this state, when the verification ECU 41 detects a user operation via the door handle sensor 47, the verification ECU 41 operates the door lock device 48. As a result, the vehicle 12 is unlocked.

  In addition, the LF transmission unit 44 transmits a request signal toward a predetermined area set in advance in the vehicle compartment. When the vehicle power is turned off, that is, in a state where the vehicle 12 cannot travel, the verification ECU 41 turns off the vehicle power when a switch signal is input from the IGSW 49 in a state where the in-vehicle verification triggered by this request signal is established. To turn on the vehicle.

<Outline of tire pressure monitoring system>
Next, an outline of the tire pressure monitoring system will be described. In the tire pressure monitoring system 11 of this example, a sensor unit provided integrally with a tire air valve is built in the tire, and tire pressure information directly detected by the sensor unit is wirelessly transmitted to the vehicle body side. A so-called direct type (valve type) system is employed.

  As shown in FIG. 1, the tire pressure monitoring system 11 includes four sensor units 14 provided on four tires 13 of a vehicle 12 and a monitoring device 30 provided on a vehicle body 15 of the vehicle 12. Each sensor unit 14 detects the air pressure of the tire 13 corresponding to itself, and transmits a wireless signal including the detected air pressure information and identification information unique to itself at a predetermined period. A radio signal from each sensor unit 14 is received by the monitoring device 30. The monitoring device 30 determines which of the four tires 13 the air pressure information included in the wireless signal is based on the identification information included in the received wireless signal. The monitoring device 30 individually monitors the air pressures of the four tires 13 based on each air pressure information. If an abnormality is detected in the pressure of any of the tires, an abnormality is detected in a specific tire through a display device 17 provided in a range visible to the driver in the passenger compartment, such as an instrument panel (instrument panel). Warning that occurred.

<Sensor unit>
The sensor unit 14 is integrally provided at the inner end of an air valve (not shown) of the tire 13. As shown in an enlarged view in the upper part of FIG. 1, the sensor unit 14 includes an acceleration sensor 21, an air pressure sensor 22, a UHF transmission unit 23, and a sensor control unit 24.

  The acceleration sensor 21 detects the acceleration accompanying the rotation of the tire 13. The air pressure sensor 22 measures the air pressure inside the tire 13. The sensor control unit 24 generates an electrical signal indicating air pressure information according to the measurement result of the air pressure sensor 22. The sensor control unit 24 changes the generation period of the electric signal according to the detection result of the acceleration sensor 21. The UHF transmission unit 23 modulates the electrical signal generated by the sensor control unit 24 and wirelessly transmits the modulated electrical signal.

  The sensor control unit 24 comprehensively controls each unit of the sensor unit 14. The memory 25 of the sensor control unit 24 stores various control programs and identification information (ID code) unique to itself. The memory 25 stores first and second generation periods T1 and T2. The first generation cycle T1 is a cycle that serves as a reference for calculating a travel generation cycle Tr that is a generation cycle of an electrical signal when the acceleration sensor 21 detects acceleration. The second generation period T2 is a reference period for calculating a stop generation period Ts that is an electric signal generation period when the acceleration sensor 21 cannot detect acceleration. The first generation cycle T1 is set shorter than the second generation cycle T2 (T1 <T2). In addition, the memory 25 stores a delay time upper limit value Tx that is an upper limit value of the delay time ΔT added to the first and second generation periods T1 and T2. The delay time ΔT is for preventing the timing at which electrical signals are generated between the plurality of sensor units 14 from continuing to overlap. The sensor unit 14 randomly determines the delay time ΔT of the next electric signal between zero and the delay time upper limit value Tx each time an electric signal is generated (0 ≦ ΔT ≦ Tx). The delay time upper limit value Tx is set very short compared to the first and second generation periods T1 and T2. In this example, the first and second generation periods T1 and T2 have the same value in all the sensor units 14.

  Based on the presence or absence of acceleration detected through the acceleration sensor 21, the sensor control unit 24 calculates a travel generation period Tr or a stop generation period Ts that is a period for actually generating an electrical signal. When the acceleration can be detected through the acceleration sensor 21, that is, when the vehicle is traveling, the generation period Tr during traveling is the sum of the first generation period T1 and the delay time ΔT (Tr = T1 + ΔT). . Since the delay time ΔT that changes every time an electric signal is generated changes in the range of 0 to Tx, the range that the travel generation cycle Tr can take can be expressed by the following (Equation 1).

T1 ≦ Tr ≦ T1 + Tx (Formula 1)
When the change in acceleration through the speed sensor 21 is not detected for a predetermined time, that is, when the vehicle is not traveling, the stop generation period Ts is obtained by adding the second generation period T2 and the delay time ΔT. (Ts = T2 + ΔT). Since the delay time ΔT that changes every time an electric signal is generated changes in the range of 0 to Tx, the range that the stop generation period Ts can take can be expressed by the following (Equation 2).

T2 ≦ Ts ≦ T2 + Tx (Formula 2)
When the vehicle travels, the sensor control unit 24 generates an electrical signal every time the traveling generation period Tr elapses, and transmits the electrical signal through the UHF transmission unit 23 as a radio signal. On the other hand, when the vehicle is stopped, the sensor control unit 24 generates an electrical signal every time the stop-time generation cycle Ts elapses, and transmits this as a radio signal through the UHF transmission unit 23. Since the first generation cycle T1 is set shorter than the second generation cycle T2 (T1 <T2), the transmission cycle of the radio signal is longer when the vehicle is stopped than when the vehicle is traveling.

  The sensor unit 14 is operated by a battery (not shown). Since the transmission cycle of the wireless signal transmitted by the sensor unit 14 is longer when the vehicle is not traveling than when the vehicle is traveling, battery consumption can be suppressed. As a result, the lifetime of the sensor unit 14 can be maintained for a longer time.

<Monitoring device>
Next, the monitoring device 30 will be described in detail. As shown in FIG. 1, the monitoring device 30 includes a UHF receiver 45 and a TPMS ECU 31. The UHF receiver 45 is connected to the TPMS ECU 31 via the first changeover switch 43. The vehicle body 15 is provided with a battery 37. The battery 37 supplies power to each part of the vehicle body 15. Each part of the vehicle body 15 is driven while consuming the electric power of the battery 37. The TPMS ECU 31 is connected to the verification ECU 41. The TPMS ECU 31 recognizes the power state of the vehicle body 15 (vehicle power on / off) through the verification ECU 41.

  The UHF receiver 45 receives a wireless signal from each sensor unit 14 without consuming the power of the battery 37 and a standby mode in which the power of the battery 37 can be consumed to receive the wireless signal from each sensor unit 14. And a non-standby mode that cannot be performed. Between the UHF receiving part 45 and the battery 37, the 2nd changeover switch 33 which switches the presence or absence of connection of these both is provided. The second changeover switch 33 switches on and off based on the third and fourth switching signals generated by the TPMS ECU 31 or the first and second switching signals generated by the verification ECU 41. The first and second switch signals are received by the second switch 33 via the TPMS ECU 31. The UHF receiver 45 enters a standby mode when power is supplied from the battery 37, and enters a non-standby mode when power is not supplied.

  The TPMS ECU 31 performs overall control of the air pressure monitoring system. The TPMS ECU 31 monitors the state of each tire 13 based on a radio signal received through the UHF receiver 45.

  Table data 34 shown in FIG. 3 is stored in the memory 31a of the TPMS ECU 31. The table data 34 is information indicating a correspondence relationship between the mounting positions (right front, left front, right rear, and left rear) of the tires 13 and the identification information ID1 to ID4 of the sensor units 14. The memory 31a has an area for storing information indicating an abnormality in tire air pressure.

  Further, the memory 31a stores a second switching timing calculation program 36. The second switching timing calculation program 36 switches the first changeover switch 43 from the first connection mode to the second connection mode when the vehicle power is turned off, that is, when the vehicle cannot travel. A third switch timing for switching the switch 33 from OFF to ON, and a fourth switch for switching the first switch 43 from the second connection mode to the first connection mode. This is a program for calculating timing. When the third switching timing is reached, the TPMS ECU 31 switches the first switch 43 from the first connection mode to the second connection mode, and indicates that the second switch 33 is switched from OFF to ON. The switching signal is generated. Further, when the fourth switching timing is reached, the TPMS ECU 31 generates a fourth switching signal indicating that the second switching switch 33 is switched from on to off.

  The TPMS ECU 31 and the verification ECU 41 are electrically connected. That is, the TPMS ECU 31 can recognize the first and second switching signals generated in the verification ECU 41. Further, the verification ECU 41 can recognize the third and fourth switching signals generated in the TPMS ECU 31.

  If the second switching signal is generated in the TPMS ECU 31 after the generation of the third switching signal and before the generation of the fourth switching signal, the TPMS ECU 31 immediately generates the third switching signal. Accordingly, the first changeover switch 43 is switched from the first connection mode to the second connection mode while the second changeover switch 33 is kept on. Further, when the first switching signal is generated in the TPMS ECU 31 after the generation of the third switching signal and before the generation of the fourth switching signal, the TPMS ECU 31 sets the first switching switch 43, and The second changeover switch 33 is not allowed to receive. That is, the first changeover switch 43 is maintained in the second connection mode.

  On the other hand, if the fourth switching signal is generated in the TPMS ECU 31 after the generation of the first switching signal and before the generation of the second switching signal, the verification ECU 41 immediately generates the first switching signal. . As a result, the first changeover switch 43 is switched from the second connection mode to the first connection mode while the second changeover switch 33 is kept on.

Each information stored in the memory 31a is registered when the vehicle is shipped or when the tire 13 is replaced.
The TPMS ECU 31 determines which one of the tires 13 the air pressure information included in the wireless signal is through comparison between the identification information included in the wireless signal received through the UHF receiver 45 and the table data 34. Further, the TPMS ECU 31 determines whether there is an abnormality in the air pressure of each tire 13 based on the air pressure information. If there is an abnormality in the tire air pressure, information indicating that is stored in the memory 31a. When information indicating an abnormality in tire air pressure is stored in the memory 31a, the TPMS ECU 31 generates a display control signal to warn to that effect. The display device 17 displays a warning that an abnormality has occurred in a specific tire in accordance with a display control signal generated in the TPMS ECU 31. The TPMS ECU 31 deletes the information indicating the abnormality in the tire air pressure stored in the memory 31a when it is determined that the abnormality in the tire air pressure has been resolved.

<Switching operation mode>
Next, switching of the operation mode of the UHF receiver 45 will be described. First, the case where the IGSW 49 is operated to switch from the vehicle power-off to the vehicle power-on will be described. It is assumed that the second changeover switch 33 is turned off. Further, it is assumed that information indicating an abnormality in tire air pressure is not stored in the memory 31a. Further, the vehicle 12 does not perform verification using the electronic key system 51 while the vehicle power is on, but only monitors tire pressure using the tire pressure monitoring system 11. For this reason, the 1st changeover switch 43 is maintained in the 1st connection mode, ie, the condition which connected UHF receiving part 45 and TPMS ECU31.

  When the vehicle power is turned on, the IGSW 49 generates a switch signal indicating that. The verification ECU 41 recognizes that the vehicle power is turned on, that is, the vehicle is allowed to travel through the monitoring of the switch signal. Further, the TPMS ECU 31 recognizes that the vehicle power is turned on through the verification ECU 41. At this time, the TPMS ECU 31 generates a second changeover switch change signal and switches the second changeover switch 33 from OFF to ON. As shown in FIG. 2, when the vehicle is allowed to travel, the operation mode of the UHF receiver 45 is in a standby state. While the vehicle is allowed to travel, the TPMS ECU 31 maintains the second changeover switch 33 on. That is, during this time, the operation mode of the UHF receiver 45 is maintained in a standby state. Accordingly, during this time, the TPMS ECU 31 can receive a radio signal from each sensor unit 14 through the UHF receiver 45. The TPMS ECU 31 determines whether there is an abnormality in the air pressure of the tire 13 based on the air pressure information included in the received radio signal. When it is determined that there is an abnormality in the air pressure, a warning is displayed through the display device 17 that an abnormality has occurred in a specific tire.

  When the vehicle power is turned on, the second changeover switch 33 may be turned on. In this case, the TPMS ECU 31 maintains the second changeover switch 33 on. That is, when the vehicle is allowed to travel, the operation mode of the UHF receiver 45 is in a standby state.

Next, the case where the IGSW 49 is operated to switch from the vehicle power on to the vehicle power off will be described.
When the vehicle power is turned off, the IGSW 49 generates a switch signal indicating that. The verification ECU 41 recognizes that the vehicle power is off, that is, that the vehicle cannot travel, through monitoring the switch signal. Further, the TPMS ECU 31 recognizes that the vehicle power is turned off through the verification ECU 41. As shown in FIG. 4, when the vehicle power is turned off, the second change-over switch 33 is on, that is, the UHF receiver 45 is in the standby mode. The first changeover switch 43 connects the first connection mode, that is, the UHF receiver 45 and the TPMS ECU 31.

  As shown in FIG. 2, even if the TPMS ECU 31 recognizes that the vehicle power is off, the TPMS ECU 31 keeps the second change-over switch 33 on until it receives wireless signals from each sensor unit, here, the four sensor units 14. That is, the UHF receiver 45 is kept in a standby state until it receives radio signals from the four sensor units 14. In FIG. 2, a portion indicated by a shaded square indicates the timing at which wireless signals are actually received from the four sensor units 14.

  When the TPMS ECU 31 receives radio signals from all the four sensor units 14, the TPMS ECU 31 generates a fourth switching timing and switches the second switch 33 from on to off. As a result, the UHF receiver 45 switches from the standby mode to the non-standby mode.

  When receiving a radio signal from one sensor unit 14, the TPMS ECU 31 calculates third and fourth switching timings based on the second switching timing calculation program 36. The TPMS ECU 31 generates a third switching signal when the third scheduled switching timing is reached. As a result, the second changeover switch 33 is switched from OFF to ON. The UHF receiver 45 switches from the non-standby mode to the standby mode. The first changeover switch 43 is switched from the first connection mode to the second connection mode. That is, the UHF receiver 45 is connected to the TPMS ECU 31.

  When the vehicle is stopped, the sensor unit 14 transmits a radio signal every time when the stop time generation period Ts is reached. At this time, the UHF receiver 45 is in a standby mode and is connected to the TPMS ECU 31. Thereby, the TPMS ECU 31 can receive a radio signal from the sensor unit 14 through the UHF receiver 45. When the reception of the radio signal of the sensor unit 14 is completed, the TPMS ECU 31 generates a fourth switching signal and switches the second switch 33 from on to off. As a result, the UHF receiver 45 switches from the standby mode to the non-standby mode. Further, the TPMS ECU 31 determines whether there is an abnormality in the air pressure of the tire 13 based on the air pressure information included in the received radio signal. When it is determined that there is an abnormality in the air pressure, information indicating that is stored in the memory 31a. When the vehicle power is turned on and information indicating an abnormality in air pressure is stored in the memory 31a when the vehicle power is turned on, the TPMS ECU 31 has an abnormality in a specific tire through the display device 17. A warning message is displayed. That is, it is possible to display a warning that an abnormality has occurred in a specific tire before the vehicle travels.

  The TPMS ECU 31 receives the fourth switching signal when the fourth relay switching timing is reached without receiving the wireless signal from the sensor unit 14 due to some factor such as radio signal interference. And the second selector switch 33 is switched from on to off. As a result, the UHF receiver 45 switches from the standby mode to the non-standby mode. The TPMS ECU 31 determines that the timing at which the second selector switch 33 is switched off, that is, the fourth switching timing, is the radio signal reception timing, and the next radio signal is determined based on the second switching timing calculation program 36. The third and fourth switching timings for receiving are calculated. Accordingly, the TPMS ECU 31 can receive the next radio signal even if the radio signal cannot be temporarily received, such as radio signal interference.

  When the vehicle power is off, the vehicle 12 performs verification using the electronic key system 51 in addition to monitoring the tire pressure using the tire pressure monitoring system 11. Hereinafter, operations of the TPMS ECU 31 and the verification ECU 41 when the timing of receiving the wireless signal of the tire pressure monitoring system 11 and the timing of receiving the wireless signal of the electronic key system 51 overlap will be described. Here, as shown in FIG. 4, the TPMS ECU 31 generates the third switching signal in the state where the first changeover switch 43 is in the first connection mode and the second changeover switch 33 is turned off. The timing t0 will be described. In FIG. 4, (1) to (4) with arrows indicate timings at which the first to fourth switching signals are generated, respectively.

  As shown in FIG. 4, when the timing t0 is reached, the TPMS ECU 31 generates a third switching signal. Accordingly, as shown in the first time chart, the first changeover switch 43 switches from the first connection mode to the second connection mode, and as shown in the second time chart, the second changeover switch 33. Switches from off to on. That is, the UHF receiver 45 is in a standby state and connected to the TPMS ECU 31. Thereby, TPMS ECU31 can receive the radio signal from sensor unit 14 (A).

  When the timing t1 is reached, the verification ECU 41 generates a first switching signal. At this time, since the TPMS ECU 31 is after the generation of the third switching signal and before the generation of the fourth switching signal, the first and second switching switches 43 and 33 receive the first switching signal. I won't let you. Therefore, as shown in the first time chart, the first changeover switch 43 is maintained in the second connection mode, and as shown in the second time chart, the second changeover switch 33 is kept in the ON state. The That is, the UHF receiving unit 45 is in a standby state and is kept connected to the TPMS ECU 31. Thereby, TPMS ECU31 can receive the radio signal from sensor unit 14 (A).

  Subsequently, at timing t2, the TPMS ECU 31 generates a fourth switching signal. At this time, the verification ECU 41 generates the first switching signal because it is after the generation of the first switching signal and before the generation of the second switching signal. Accordingly, as shown in the first time chart, the first changeover switch 43 switches from the second connection mode to the first connection mode, and as shown in the second time chart, the second changeover switch 33. Remains on. That is, the UHF receiving unit 45 is maintained in a standby state and connected to the verification ECU 41. Thereby, collation ECU41 can receive the radio signal from electronic key 52 (B).

  Subsequently, at timing t3, the TPMS ECU 31 generates a third switching signal. Accordingly, as shown in the first time chart, the first changeover switch 43 switches from the first connection mode to the second connection mode, and as shown in the second time chart, the second changeover switch 33. Remains on. That is, the UHF receiving unit 45 is maintained in a standby state and is connected to the TPMS ECU 31. Thereby, TPMS ECU31 can receive the radio signal from sensor unit 14 (A).

  Subsequently, at timing t4, the TPMS ECU 31 generates a fourth switching signal. At this time, the verification ECU 41 generates the first switching signal because it is after the generation of the first switching signal and before the generation of the second switching signal. Accordingly, as shown in the first time chart, the first changeover switch 43 switches from the second connection mode to the first connection mode, and as shown in the second time chart, the second changeover switch 33. Remains on. That is, the UHF receiving unit 45 is maintained in a standby state and connected to the verification ECU 41. Thereby, collation ECU41 can receive the radio signal from electronic key 52 (B).

  Subsequently, at timing t5, the verification ECU 41 generates a second switching signal. Therefore, as shown in the second time chart, the second changeover switch 33 is switched from on to off. That is, the UHF receiver 45 switches from the standby state to the non-standby state. As a result, the TPMS ECU 31 cannot receive the wireless signal from the sensor unit 14 and the verification ECU 41 cannot receive the wireless signal from the electronic key 52 (C). As shown in the first time chart, the first changeover switch 43 is maintained in the first connection mode.

  Subsequently, at timing t6, the TPMS ECU 31 generates a third switching signal. Accordingly, as shown in the first time chart, the first changeover switch 43 switches from the first connection mode to the second connection mode, and as shown in the second time chart, the second changeover switch 33. Switches from off to on. That is, the UHF receiver 45 is in a standby state and connected to the TPMS ECU 31. Thereby, TPMS ECU31 can receive the radio signal from sensor unit 14 (A).

  Subsequently, at timing t7, the TPMS ECU 31 generates a fourth switching signal. Therefore, as shown in the second time chart, the second changeover switch 33 is switched from on to off. That is, the UHF receiver 45 switches from the standby state to the non-standby state. As a result, the TPMS ECU 31 cannot receive the wireless signal from the sensor unit 14 and the verification ECU 41 cannot receive the wireless signal from the electronic key 52. As shown in the first time chart, the first changeover switch 43 is maintained in the second connection mode (C).

  Subsequently, at timing t8, the verification ECU 41 generates a first switching signal. Accordingly, as shown in the first time chart, the first changeover switch 43 switches from the second connection mode to the first connection mode, and as shown in the second time chart, the second changeover switch 33. Switches from off to on. That is, the UHF receiver 45 is in a standby state and is connected to the verification ECU 41. Thereby, collation ECU41 can receive the radio signal from sensor unit 14 (A).

  Subsequently, at timing t9, the verification ECU 41 generates a second switching signal. Therefore, as shown in the second time chart, the second changeover switch 33 is switched from on to off. That is, the UHF receiver 45 switches from the standby state to the non-standby state. As a result, the TPMS ECU 31 cannot receive the wireless signal from the sensor unit 14 and the verification ECU 41 cannot receive the wireless signal from the electronic key 52 (C). As shown in the first time chart, the first changeover switch 43 is maintained in the first connection mode.

  As described above, when the period when the first changeover switch 43 is set to the first connection mode and the period when the second connection mode is set overlap (timing t1 to t2 and timing t3 to t4 in FIG. 4). The TPMS ECU 31 switches the first changeover switch 43 from the first connection mode to the second connection mode.

As described above in detail, according to the present embodiment, the following effects can be obtained.
(1) When the period during which the first changeover switch 43 is set to the first connection mode and the period during which the second connection mode is set overlap, the TPMS ECU 31 changes the first changeover switch 43 from the first connection mode to the second connection mode. Switch to the connection mode. Thereby, the TPMS ECU 31 can receive a radio signal from the sensor unit 14. Thereby, TPMS ECU31 can monitor the air pressure of a tire.

  (2) A first changeover switch 43 connected to the UHF receiver 45 is provided. The first changeover switch 43 selectively connects the TPMSECU 31 and the verification ECU 41 based on the third switch signal generated by the TPMS ECU 31 and the first switch signal generated by the verification ECU 41. When the first changeover switch 43 receives the third changeover signal generated by the TPMSECU 31, the first changeover switch 43 enters the second connection mode for connecting the UHF receiving unit 45 and the TPMSECU 31. As described above, the TPMS ECU 31 can receive the radio signal from the sensor unit 14 only by switching the simple configuration of the first changeover switch 43.

  (3) When the ignition is off, the TPMS ECU 31 receives the radio signal from the sensor unit 14 and calculates the third switching timing based on the second switching timing calculation program. When the third switching timing is reached, the TPMS ECU 31 generates a third switching signal, switches the first selector switch 43 from the non-standby state to the standby state, and switches from the first connection mode to the second connection mode. Switch. Thereby, the TPMS ECU 31 can receive the radio signal from the sensor unit 14 in synchronization with the transmission of the radio signal of the sensor unit 14 when the ignition is turned off. That is, the TPMS ECU 31 monitors the tire air pressure even while the ignition is off. When the abnormality of the air pressure of the tire 13 is detected, the TPMS ECU 31 stores information indicating that in the memory 31a, and when the ignition is turned on, an abnormality has occurred in a specific tire through the display device 17. A warning message is displayed. Thus, according to the present embodiment, the TPMS ECU 31 can monitor the tire pressure not only when the ignition is on, but also when the ignition is off.

  (4) When an abnormality occurs in a specific tire while the ignition is off, the TPMS ECU 31 displays a warning that an abnormality has occurred in the specific tire through the display device 17 when the ignition is switched on. I do. That is, it is possible to display a warning that an abnormality has occurred in a specific tire before the vehicle travels.

  (5) When the acceleration is not detected, the sensor unit 14 generates a radio signal at the stop generation period Ts and transmits it regardless of whether there is an abnormality in the air pressure. That is, the transmission cycle is constant. For this reason, the sensor unit 14 consumes less power than a sensor unit that continuously transmits wireless signals when there is an abnormality in air pressure.

  (6) The TPMS ECU 31 calculates the fourth switching timing based on the second switching timing calculation program. If the TPMS ECU 31 cannot receive a wireless signal before the fourth switching timing is reached, the TPMS ECU 31 generates a fourth switching signal and switches the second switch 33 from on to off. Thereby, the power consumption of the battery 37 can be suppressed. As a result, it can suppress that the battery 37 runs out.

  (7) The TPMS ECU 31 keeps the second change-over switch 33 on until the wireless signal is received from the four sensor units 14 after the ignition is turned off. That is, the standby state of the verification ECU 41 is maintained. Thereby, TPMS ECU31 can synchronize the timing which a radio signal is transmitted from each sensor unit 14, and the timing which maintains collation ECU41 in a standby state.

  (8) If the TPMS ECU 31 cannot receive a wireless signal before the fourth switching timing is reached, the TPMS ECU 31 calculates the third and fourth switching timings for the next wireless signal using the fourth switching timing as the reception timing. . Then, when the third switching timing is reached, the TPMS ECU 31 generates a third switching signal and switches the second switch 33 on and off. Thereby, even if a radio signal cannot be received once, the radio signal transmitted next can be received. Further, by repeating this, the TPMS ECU 31 can suitably receive a radio signal from the sensor unit 14 when the vehicle is stopped. Furthermore, when the wireless signal cannot be received, the power consumption of the battery 37 when the vehicle is stopped can be suppressed as compared with the case where the standby state of the UHF receiver 45 is maintained.

[Second Embodiment]
A second embodiment embodying the present invention will be described below with reference to FIGS. The main difference between the present embodiment and the first embodiment is the configuration of the electronic key 52. For this reason, for convenience of explanation, the same parts as those in the first embodiment are denoted by the same reference numerals, and the explanation thereof is omitted.

<Electronic key>
As shown in FIG. 1, the electronic key 52 is provided with a lock switch 56 and an unlock switch 57 connected to the electronic key control unit 53. These lock switch 56 and unlock switch 57 can be pushed. When the lock switch 56 and the unlock switch 57 are operated, the electronic key control unit 53 generates an electrical signal (wireless signal) indicating that. The UHF transmission unit 55 converts the generated wireless signal into a UHF band radio signal, and transmits this to the vehicle 12 side.

<Onboard equipment>
The verification ECU 41 generates a first switching signal at a normal generation cycle or a superposition generation cycle in order to receive a wireless signal when the vehicle power is off. The normal generation cycle is longer than the superposition generation cycle. When the first switching signal is input, the first changeover switch 43 is switched from the non-standby mode to the standby mode and from the second connection mode to the first connection mode. When the verification ECU 41 receives a wireless signal via the UHF receiver 45, the verification ECU 41 performs verification of the wireless signal (wireless verification). When it is determined that the wireless signal is transmitted from the electronic key 52 corresponding to itself through the wireless verification, the verification ECU 41 operates the door lock device 48 based on the information included in the wireless signal to Switch between locking and unlocking.

<Switching operation mode>
Next, switching of the operation mode of the UHF receiver 45 will be described. In addition, since it is the process similar to 1st Embodiment about the case where vehicle power supply is ON, the description is abbreviate | omitted.

  The verification ECU 41 generates the first switching signal in the normal generation cycle when the vehicle power is off. As a result, the first changeover switch 43 switches from the non-standby mode to the standby mode, and also switches from the second connection mode to the first connection mode. At this time, when the lock switch 56 or the unlock switch 57 of the electronic key 52 is operated and a wireless signal is transmitted from the electronic key 52, the verification ECU 41 receives the wireless signal through the UHF receiver 45.

  In FIG. 5, as shown at timing t <b> 11, the verification ECU 41 receives the third switching signal in the TPMS ECU 31 after the generation of the first switching signal generated in the normal generation cycle and before the generation of the second switching signal. If generated, the first switching signal is then generated at a superposition generation cycle shorter than the normal generation cycle by a predetermined number of times. That is, in FIG. 5, as shown at timings t12, t13, and t14, the verification ECU 41 generates the first switching signal for a predetermined number of times (here, three times) in the superposition generation cycle. As a result, the first changeover switch 43 is switched from the non-standby mode to the standby mode, and is switched from the second connection mode to the first connection mode more than usual. When many users operate the lock switch 56 or the unlock switch 57 and determine that the door lock device 48 does not operate, they operate the operated switch continuously. For this reason, even if the verification ECU 41 cannot receive the wireless signal once, it easily receives the wireless signal again.

As described above in detail, according to the present embodiment, the following effects can be obtained in addition to the effects described in the above embodiment (1).
(9) The verification ECU 41 is a case where the verification ECU 41 generates the third switching signal in the TPMS ECU 31 after the generation of the first switching signal generated in the normal generation cycle and before the generation of the second switching signal. In this case, the first switching signal is generated a predetermined number of times (for example, three times) in the superposition generation cycle. As a result, the first changeover switch 43 is switched from the non-standby mode to the standby mode, and is switched from the second connection mode to the first connection mode more than usual. For this reason, even if collation ECU41 cannot receive a wireless signal once, it can receive a wireless signal again.

In addition, you may change each said embodiment as follows.
In the second embodiment, the verification ECU 41 may not transmit a request signal. Even if comprised in this way, the effect similar to the effect as described in said (1) and (4)-(8) can be acquired.

  In each of the above-described embodiments, the TPMS ECU 31 continuously detects a specific sensor unit due to some factor even if the second change-over switch 33 is switched from OFF to ON and the verification ECU 41 is in a standby state when the ignition is OFF. 14 may not receive a radio signal. In this case, if the TPMS ECU 31 cannot receive the radio signal from the specific sensor unit 14 continuously for a specified number of times (for example, three times), the second changeover switch until the radio signal is received from all the four sensor units 14. Keep 33 on. That is, the standby state of the verification ECU 41 is maintained. Thereby, TPMS ECU31 can receive a radio signal from the specific sensor unit 14 which could not be received until now. When receiving the wireless signal from the sensor unit, the TPMS ECU 31 can calculate the third and fourth switching timings for the next wireless signal based on the second switching timing calculation program. Then, the TPMS ECU 31 generates a third switching signal based on the third switching timing and switches the second switching switch 33 on and off. With this configuration, it is easier to receive a radio signal from the sensor unit 14.

  In each of the above embodiments, when an abnormality occurs in the air pressure of the tire 13, the sensor unit 14 may continuously transmit a radio signal indicating that fact. If comprised in this way, the radio signal which shows the said abnormality can be made to receive TPMS ECU31 earlier.

In each of the above embodiments, the sensor unit 14 may transmit a radio signal according to an instruction from an initiator attached to each tire 13.
-Vehicle 12 which adopts tire pressure monitoring system 11 of each above-mentioned embodiment may be any models, such as a gasoline car, a hybrid car, a plug-in hybrid car, an electric car, and a fuel cell car.

DESCRIPTION OF SYMBOLS 11 ... Tire pressure monitoring system, 12 ... Vehicle, 13 ... Tire, 14 ... Sensor unit, 15 ... Vehicle body, 17 ... Display device, 21 ... Acceleration sensor, 22 ... Air pressure sensor, 23 ... Transmission part, 24 ... Sensor control part, 25 ... Memory,
DESCRIPTION OF SYMBOLS 30 ... Monitoring apparatus, 31 ... TPMSECU (monitoring control part), 31a ... Memory, 33 ... 2nd changeover switch, 34 ... Table data, 36 ... 2nd switching timing calculation program, 37 ... Battery, 40 ... Onboard equipment, DESCRIPTION OF SYMBOLS 41 ... Verification ECU, 41a ... Memory, 42 ... Power supply state monitoring part, 43 ... 1st changeover switch, 44 ... LF transmission part, 45 ... UHF reception part, 46 ... 1st switching timing calculation program, 47 ... Door handle Sensor, 48 ... Door lock device, 49 ... Ignition switch, 51 ... Electronic key system, 52 ... Electronic key, 53 ... Electronic key controller, 53a ... Memory, 54 ... LF receiver, 55 ... UHF transmitter, 56 ... Lock Switch, 57 ... Unlock switch.

Claims (3)

Wireless systems in both a tire pressure monitoring system that monitors tire pressure through a wireless signal including tire pressure information from a sensor unit provided in each tire, and an electronic key system that checks a wireless signal transmitted from an electronic key In the integrated receiver that receives the signal,
A first mode for receiving a radio signal from the electronic key and a second mode for receiving a radio signal from the sensor unit are provided, and the period for the first mode overlaps the period for the second mode. If so, the integrated receiver is set to the second mode. The integrated receiver according to claim 1.
A first changeover switch that selectively connects a monitoring control unit that controls the tire pressure monitoring system and a verification control unit that controls the electronic key system is provided, and the first changeover switch is set to the first mode. An integrated receiver characterized in that when the period and the period to be set in the second mode overlap, the monitoring controller is connected. The integrated receiver according to claim 1 or 2,
It has a third mode that does not receive radio signals from the electronic key and sensor unit, and switches from the third mode to the first mode in the second cycle that is set to the first cycle or a shorter cycle. And
When the mode is switched from the third mode to the first mode in the first period, the period set as the first mode overlaps the period set as the second mode, and then the third mode is set in the second period. The integrated receiver is switched to the first mode.