JP2005193861A - Tire condition monitoring system for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent transmission signals from respective detection devices from being mixed by simultaneously activating the detection devices of an own vehicle and the other vehicle by transmitted signal from a monitoring device in a tire condition monitoring system for activating the detection device by transmitting the signal from the monitoring device to the detection device in a tire. <P>SOLUTION: The monitoring device transmits a detection requirement signal of the tire condition (air pressure or the like) in every tire utilizing transmitters provided near the respective tires mounted on the vehicle (110, 130). The detection requirement signal comprises an activation signal for feeding electricity to the detection device, vehicle ID for discriminating the vehicle and sensor ID for discriminating the tire. The detection device is activated by receiving the activation signal. Thereafter, when it is coincident with the vehicle ID and the sensor ID previously registered with the vehicle ID and the sensor ID successively transmitted from the transmitter (210, 240: coincident), the tire condition (air pressure, temperature) is detected and the detection result (header + detection data) is transmitted. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a plurality of detection devices that detect the state (air pressure, etc.) of a plurality of tires mounted on a vehicle and transmit them wirelessly, and by receiving a transmission signal from each detection device, the tire state of each tire is determined. The present invention relates to a vehicle tire condition monitoring system including a monitoring device for monitoring.

  Conventionally, in a vehicle equipped with an air-injection type tire, in order to enhance safety during traveling, the tire condition such as air pressure and temperature is detected for each tire mounted on the vehicle, and the detection result is wirelessly transmitted. There is known a tire condition monitoring system that incorporates a detection device that transmits data and receives a transmission signal from the detection device on the monitoring device side, which is a vehicle-mounted device, so that the state of each tire can be automatically monitored. .

  As this tire condition monitoring system, generally, a configuration in which each detection device in a tire is periodically activated to transmit tire information is known. Since the detection devices operate independently regardless of the operating state, the power consumption of the detection devices becomes unnecessarily large, and it is necessary to incorporate a large capacity battery in the tire, or the detection results are transmitted simultaneously from each detection device. As a result, there is a problem that the detection result from each detection device may not be restored on the monitoring device side.

  Therefore, in order to prevent such problems, a transmission / reception function is added to the monitoring device and the detection device, and when the monitoring device monitors the tire condition, the identification code set for each detection device from the monitoring device side. There is also proposed a monitoring system that selectively activates a specific detection device corresponding to the identification code by transmitting one of these as an activation signal (see, for example, Patent Document 1).

According to the proposed tire condition monitoring system, the monitoring apparatus selectively activates any one of a plurality of detection apparatuses mounted on the vehicle, and determines the condition of the tire in which the detection apparatus is incorporated. Since it is possible to detect, it is possible to suppress the operating time of the detection device in each tire to the minimum necessary, to suppress the consumption of the battery incorporated in the tire, and each detection device operates simultaneously. Can be prevented.
JP-A-8-244423

  However, in the proposed tire condition monitoring system, since the monitoring device activates the detection device in the tire by transmitting an activation signal, a plurality of vehicles equipped with the tire condition monitoring system are present in close proximity. In such a case, when the monitoring device of a specific vehicle transmits an activation signal, not only the detection device in the tire of the vehicle but also the detection device of another vehicle is activated. This causes a problem that the transmission signal from the detection device may interfere and the tire condition of the host vehicle cannot be monitored.

  The present invention has been made in view of such problems. A detection device that detects a tire state such as air pressure and transmits a detection result to the monitoring device is incorporated in the tire, and a start signal is sent from the monitoring device to the detection device. In the vehicle tire condition monitoring system in which the detection device is activated by transmitting, when the monitoring device transmits the activation signal, the detection devices of the own vehicle and the other vehicle are activated, and each detection device An object of the present invention is to prevent interference of the transmission signal.

  In the tire condition monitoring system of the present invention made to achieve such an object, the monitoring device detects a detection request signal including vehicle identification information unique to the vehicle with respect to the detection device incorporated in the tire to be monitored. Is transmitted wirelessly. Then, the detection device that has received the detection request signal determines whether or not the vehicle identification information in the detection request signal matches the vehicle identification information registered in advance, and the vehicle identification information matches. The tire condition including the tire air pressure is detected, and the detection result is transmitted. The monitoring device receives the detection result transmitted from the detection device, thereby monitoring the tire condition of each tire of the vehicle and notifying the occupant of the monitoring result (specifically, abnormality of the tire condition, etc.). .

  Therefore, according to the tire condition monitoring system of the present invention, the detection device does not detect and transmit the tire condition by receiving the detection request signal transmitted from the monitoring device of another vehicle. The detection device that responds to the detection request signal transmitted by the monitoring device can be limited to the detection device of the host vehicle.

  Therefore, according to the present invention, the tire condition of the host vehicle can be satisfactorily monitored on the monitoring device side. Further, since the detection device does not detect the tire condition or the like by the detection request signal from the monitoring device of another vehicle, the power consumption of the detection device can be suppressed.

  By the way, in the present invention, the monitoring device activates the detection device in the tire by transmitting a detection request signal with vehicle identification information to each detection device. However, the detection request signal transmitted by the monitoring device is automatically detected. When the detection devices simultaneously reach a plurality of detection devices of the vehicle and simultaneously start detection operations and transmit detection results simultaneously, transmission signals from the detection devices interfere with each other, and detection by the detection devices on the monitoring device side It is possible that the result cannot be restored.

  Therefore, in the tire condition monitoring device of the present invention, in order to prevent such a problem, the time from when the detection device starts the detection operation until the detection result is transmitted is set to a different time for each tire detection device. The transmission means used by the monitoring device to transmit a detection request signal to each detection device is arranged in the vicinity of each detection device (in other words, each tire) and transmitted from each transmission device. The transmission power of each transmission means is set so that the detection request signal reaches only the detection device arranged in the vicinity of each transmission means, and when the monitoring device transmits the detection request signal to each detection device, the signal is transmitted. It is preferable that the detection request signal reaches only the detection device to be monitored at that time by selectively switching the transmission means used for this.

  Then, when the time from when the tire detection device detects the tire condition until the detection result is transmitted is set to a different time as in the former case, the monitoring device applies to all detection devices of the host vehicle. Since the detection request signal can be transmitted at the same time, only one transmission means is provided on the monitoring apparatus side, and the apparatus configuration is simplified compared to the case where a transmission means is provided for each detection apparatus as in the latter case. it can.

  Further, even when the transmission device on the monitoring device side is single as described above or when a plurality of transmission devices are provided for each detection device, the transmission signal from each detection device is In order to prevent interference more reliably, the monitoring device transmits one of the tire identification information set for each tire in addition to the vehicle identification information when transmitting the detection request signal. For the detection device, when the detection request signal transmitted from the monitoring device is received, only when the vehicle identification information and the tire identification information match the preset identification information, It may be configured to detect the tire condition and transmit the detection result.

  In other words, in this way, when the monitoring device transmits the detection request signal, only the detection device corresponding to the tire identification information given to the detection request signal transmits the detection result. By receiving the detection results, the state of each tire mounted on the vehicle can be reliably monitored for each tire, and the detection results are simultaneously transmitted from a plurality of detection devices. It is possible to more reliably prevent the transmission signal from interfering.

  Further, in this case, if the position of each tire specified by the tire identification information is registered in advance on the monitoring device side, the tire state acquired after transmission of the detection request signal on the monitoring device side is mounted on the vehicle. It becomes possible to identify which tire state of the plurality of tires.

  However, since the position of the tire in the vehicle (particularly an automobile) is changed by the user in accordance with the wear state of the tire (so-called rotation), the vehicle is based on the tire identification information on the monitoring device side as described above. In order to be able to grasp the position of each tire mounted on the vehicle, it is desirable to be able to automatically update the information for that purpose.

  And in order to do this, the monitoring device is mounted on the vehicle from each of the transmission means for each transmission means under a predetermined condition set in advance with a plurality of transmission means arranged in the vicinity of each tire. Tire identification information of the tires located in the vicinity of each transmission means by sequentially transmitting the tire identification information of each of the tires, and then determining whether or not there is a response from the detection device corresponding to the tire identification information Tire position specifying means for specifying, when the monitoring device monitors the tire state of each tire, based on the relationship between the position of each transmitting means specified by the tire position specifying means and the tire identification information, By transmitting a detection request signal including tire identification information of each tire via a transmission unit corresponding to the tire identification information, the tire state of each tire is monitored in order. Good.

  In other words, in this way, the relationship between the tire identification information grasped on the monitoring device side and the tire position (in other words, the position of the transmission means) is different from the actual tire arrangement due to the rotation of the tire. Even if it becomes, since the relationship is updated to the one corresponding to the actual tire arrangement by the operation of the tire position specifying means, the monitoring device side uses a plurality of transmission means for each tire. The tire condition is monitored, and when an abnormality occurs in the tire condition, the tire in which the abnormality has occurred can be identified and notified to the occupant.

Embodiments of the present invention will be described below.
FIG. 1 is an explanatory diagram showing the overall configuration of a tire condition monitoring system (hereinafter also simply referred to as a monitoring system) of an embodiment to which the present invention is applied.

  As shown in FIG. 1, the monitoring system of the present embodiment is an air injection type that constitutes front and rear left and right wheels (left front wheel: FL, right front wheel: FR, left rear wheel: RL, right rear wheel: RR) of the vehicle 2. Tubeless tires (hereinafter simply referred to as tires) 4FL, 4FR, 4LR, and 4RR are provided with detection devices 10FL, 10FR, 10RL, and 10RR.

  Each of the detection devices 10FL to 10RR detects an air pressure or the like (air pressure and temperature in the present embodiment) in each of the tires 4FL to 4RR, and the detection result is converted into an ultrahigh frequency (UHF) band RF signal (for example, a frequency of 315 MHz). Signal) is wirelessly transmitted to the monitoring device 40 on the vehicle body side.

  Further, in the vicinity of the tires 4FL to 4RR on the vehicle body side, as a transmission means of the present invention, a long wave (LF) band signal (for example, a frequency of 135 kHz) is transmitted to the detection devices 10FL to 10RR in the tires 4FL to 4RR. The transmitters 30FL to 30RR are arranged to transmit power to the detection devices 10FL to 10RR and start the detection devices 10FL to 10RR by transmitting the signal), and the detection devices 10FL to 10RR are connected to the transmitters. It is activated upon receiving a transmission signal from 30FL to 30RR, and transmits a detection result such as air pressure to the monitoring device 40.

  The transmission power from each of the transmitters 30FL to 30RR is set so that the LF signal reaches only the detection devices 10FL to 10RR corresponding to the respective transmitters 30FL to 30RR (LF indicated by a two-dot chain line in FIG. 1). As for the transmission power of the RF signal from each of the detection devices 10FL to 10RR, the RF signal reaches the reception antenna 42 on the monitoring device 40 side, and the detection result (detection data) of the tire condition is detected on the monitoring device 40 side. It is set so that it can be restored.

  On the other hand, the monitoring device 40 activates each of the detection devices 10FL to 10RR by individually transmitting a detection request signal to each of the detection devices 10FL to 10RR via the transmitters 30FL to 30RR, and then the activated detection device. The RF signal transmitted from 10FL to 10RR is received by the receiving antenna 42, and the received signal is demodulated to monitor the tire condition (air pressure, temperature, etc.) of each tire 4FL to 4FR, and the monitoring result is By outputting to the notification device 60 provided near the driver's seat, the occupant is notified of the tire condition.

  The notification device 60 is composed of a display device for displaying the tire condition and an alarm device such as a buzzer and a speaker for notifying the sound when the tire condition is abnormal. Displayed on the display device, and when the tire condition is abnormal, the display device identifies and displays the tire in which the abnormality has occurred, and generates an alarm sound from the alarm device.

  Next, the detection devices 10FL to 10RR, the transmitters 30FL to 30RR, and the monitoring device 40 are each configured as shown in FIG. Since the detection devices 10FL to 10RR and the transmitters 30FL to 30RR provided for each wheel have the same configuration, FIG. 2 shows one detection device 10 and one transmitter 30. In the following description, detection devices 10FL to 10RR for each wheel are collectively referred to as detection device 10, and transmitters 30FL to 30RR for each wheel are collectively referred to as transmitter 30.

  As shown in FIG. 2, the detection device 10 includes a receiving antenna 12 that receives a transmission radio wave (LF signal) from the transmitter 30, and a storage capacitor (not shown) that rectifies the received signal from the receiving antenna 12. A power supply circuit 14 that charges and generates a DC constant voltage with the electric power charged in the capacitor and supplies the DC constant voltage to the internal circuit of the detection device 10; and a reception circuit 16 that restores information included in a reception signal from the reception antenna 12. The pressure sensor 22 that detects the air pressure in the tire 4, the temperature sensor 24 that detects the temperature in the tire 4, and the air pressure and temperature data detected by each of the sensors 22, 24 detect the tire condition. As a signal (RF signal), based on the information restored by the transmission circuit 28 and the reception circuit 16 that is transmitted from the transmission antenna 26, the monitoring device 40 and the detection device 10 It is determined whether or not a request for detecting a tire condition is transmitted, and when it is determined that a detection request has been transmitted, the tire condition (air pressure and temperature) is detected via the pressure sensor 22 and the temperature sensor 24. And a control circuit 20 that transmits the detection result (detection data) from the transmission circuit 28.

  The control circuit 20 is composed of a microcomputer centered on a CPU, ROM, RAM, and the like, and includes identification information (vehicle identification information: hereinafter also referred to as vehicle ID) specific to the vehicle on which the monitoring system is mounted and the detection. There is provided an EEPROM 20a which is a nonvolatile memory in which identification information (tire identification information: hereinafter also referred to as sensor ID) unique to the tire in which the device 10 is incorporated is stored in advance. Then, the control circuit 20 determines whether or not a tire condition detection request for the detection device 10 has been transmitted from the monitoring device 40 based on the identification information registered in the EEPROM 20a.

  Further, since the transmission circuit 28 used for transmitting the tire state detection data transmits the detection data as a UHF band RF signal, a local oscillator for generating a UHF band carrier wave, and the local oscillator And a modulation circuit that modulates the carrier wave generated according to the output data (detection result) from the control circuit 20, and transmits the RF signal obtained by modulating the carrier wave by the modulation circuit from the transmission antenna 26.

  Similarly to the reception antenna 42 on the monitoring device 40 side, the transmission antenna 26 is configured by an antenna capable of transmitting and receiving a signal in the UHF band (for example, 315 MHz), and the reception antenna 12 is transmitted from the transmitter 30. In order to receive the LF signal, a resonance antenna that receives the LF signal using the resonance between the capacitor and the coil is used.

  Note that the internal circuits of the detection device 10 such as the reception circuit 16, the control circuit 20, and the transmission circuit 28 are all operated by receiving a DC constant voltage generated by the power supply circuit 14. A battery for supplying power to the detection device 10 is not provided in the tire 4 provided with. On the other hand, since the transmitter 30 and the monitoring device 40 are so-called in-vehicle devices, the transmitter 30 and the monitoring device 40 operate by receiving power supply from the in-vehicle battery mounted on the vehicle.

  Next, the transmitter 30 drives the transmission antenna 32 in accordance with the transmission antenna 32 configured using a capacitor and a coil, similarly to the reception antenna 12 in the detection device 10, and the transmission data output from the monitoring device 40. The drive circuit 34 is configured to resonate (in other words, resonate).

  In addition, the monitoring device 40 includes a plurality (four for front, rear, left and right wheels in this embodiment) for outputting transmission data to the transmitter 30 for each wheel (specifically, 30FL to 30RR). The interface circuit (hereinafter referred to as I / F circuit) 46 and the transmission data are sequentially output to each transmitter 30 via each I / F circuit 46, so that the corresponding detection device 10 is transmitted from each transmitter 30. A control circuit 50 for transmitting a detection request signal, a reception circuit 44 for receiving the RF signal transmitted from the detection device 10 via the reception antenna 42 and restoring the tire state detection data transmitted by the detection device 10; Is provided.

  Like the control circuit 20 in the detection device 10, the control circuit 50 is configured by a microcomputer centered on a CPU, ROM, RAM, and the like. The vehicle ID of the vehicle on which the monitoring system is mounted, and the monitoring system Non-volatile memory in which sensor IDs assigned to each of the detection devices 10 constituting the tire, or tire position data representing the relationship between the sensor ID and the position of the tire 4 corresponding to the sensor ID, etc. are stored in advance The EEPROM 50a is provided.

  When transmitting a detection request signal to each detection device 10, the control circuit 50 reads the vehicle ID, the sensor ID of the tire 4 to be detected and the position of the tire 4 from the EEPROM 50, and reads them. By transmitting the vehicle ID and the sensor ID sequentially from the transmitter 30 arranged at the tire position, a detection request signal is transmitted to the detection device 10 in the tire 4 that is the detection target.

  In addition, after the detection request signal is transmitted, a transmission signal (RF signal) from the detection device 10 that has transmitted the detection data is received by the reception antenna 42, and when the detection data is restored by the reception circuit 44, the control circuit 50 captures the restored detection data and outputs it to the notification device 60 to notify the occupant of the tire condition.

  Next, the tire state monitoring process executed by the control circuit 50 in the monitoring device 40 in this way to monitor the state of each tire mounted on the vehicle, and the control in the detection device 10 in conjunction with this processing The detection data transmission process executed by the circuit 20 will be described in detail along the flowchart shown in FIG.

  The tire condition monitoring process shown in FIG. 3 is a process that is sequentially executed for each of the detection devices 10FL to 10RR, and the detection data transmission process is performed by one detection device 10 that is activated by the tire condition monitoring process. It is a process to be executed.

  As shown in FIG. 3, when the monitoring device 40 starts the tire condition monitoring process, first, in step 110 (hereinafter, “step” will be referred to as “S”), transmission arranged near the tire 4 currently being monitored. The time required for the power supply circuit 14 to generate the power supply voltage on the detection apparatus 10 side to operate the internal circuit from the machine 30 (hereinafter referred to as the monitoring target transmitter), continuously using the unmodulated LF signal as a start signal Then, the vehicle ID is transmitted from the monitoring target transmitter 30 by outputting a binary signal corresponding to the vehicle ID to the monitoring target transmitter 30.

  Then, in the detection device 10 in the tire 4 located in the vicinity of the monitoring target transmitter 30, the power supply circuit 14 starts generating a power supply voltage by the activation signal from the monitoring target transmitter 30, and the control circuit 20 detects Start the data transmission process. In this detection data transmission process, first, in S210, the vehicle ID transmitted from the monitoring device 40 side is fetched from the receiving circuit 16, and the vehicle ID matches the vehicle ID stored in the EEPROM 20a. If the vehicle IDs do not match, the process ends. If the vehicle IDs match, a transmission ACK signal is transmitted from the transmission circuit 28.

  For this reason, on the monitoring device 40 side, after transmitting the activation signal and the vehicle ID in S110, the process proceeds to S120, and the reception circuit 44 has received the ACK signal from the detection device 10 for a predetermined time. By determining whether or not the ACK signal is transmitted from the detection device 10 in the vicinity of the monitored transmitter 30 and when the reception circuit 44 determines that the ACK signal is received from the detection device 10, it continues. The process proceeds to S <b> 130, and this time, a sensor ID that identifies the tire 4 (and thus the detection device 10) that is currently monitored is read from the EEPROM 50 a, and this sensor ID is transmitted from the monitored transmitter 30.

  In addition, although sensor ID is the identification information provided for every tire 4, it is EEPROM50a so that sensor ID of the detection apparatus 10 in the tire 4 used as monitoring object can be specified by the process of said S130. In FIG. 4, tire position data as shown in FIG. 4A representing the relationship between the tire position (FL, FR,...) And the sensor ID (A, B,...) Is stored in advance.

  Next, on the detection device 10 side, after transmitting the ACK signal from the transmission circuit 28 in S220 as described above, the sensor ID is transmitted from the monitoring device 40 side. During a predetermined time, a reception process for receiving the sensor ID transmitted from the monitoring device 40 via the transmitter 30 is executed. In S240, the sensor ID received in this reception process is stored in the EEPROM 20a. It is determined whether or not it matches the sensor ID being set.

  If it is determined in S240 that the sensor IDs do not match, the process is terminated. If it is determined that the sensor IDs match, the process proceeds to S250, and the pressure sensor 22 and the temperature sensor. 24 is used to detect the air pressure and temperature in the tire 4, add a transmission header to the detected data, and output the detected data to the transmission circuit 28, thereby transmitting the detection data from the transmission circuit 28.

  For this reason, on the monitoring device 40 side, after transmitting the sensor ID in S130, the process proceeds to S140, and it is determined whether or not the detection data is received by the receiving circuit 44 for a predetermined time. When the receiving circuit 44 waits for the detection data to be received and determines that the detection data has been received by the receiving circuit 44, the process proceeds to S150, where the tire abnormalities (air pressure drop, temperature rise) based on the received data. Etc.) and in S160, the received data and the tire abnormality determination result are output to the notification device 60, so that the notification device 60 is notified of the tire condition.

  Note that if the control circuit 50 on the monitoring device 40 side determines that the ACK signal cannot be received in S120, or if it is determined that the detection data cannot be received in S140, it is determined that some kind of communication abnormality has occurred. Then, the tire condition monitoring process is temporarily ended, and then the tire condition monitoring process for the tire 4 to be monitored is started. Further, the control circuit 50 on the monitoring device 40 side once ends the tire condition monitoring process after outputting the current reception / determination result to the notification device 60 in S160, and then the tire 4 to be monitored next. The tire condition monitoring process is started.

  As described above, in the monitoring system of the present embodiment, the transmitters 30FL to 30RR are provided corresponding to the detection devices 10FL to 10RR in the tires 4FL to 4RR, and the monitoring device 40 is illustrated in FIG. As shown in b), by transmitting the activation signal and the vehicle ID from the transmitter 30 selected from the transmitters 30FL to 30RR, the vehicle (in other words, the vehicle) to be monitored at that time is transmitted. The detection device 10 in the tire 4 (with matching ID) is activated.

  Further, when the monitoring device 40 receives the ACK signal from the detection device 10 of the host vehicle activated by the transmission of the activation signal and the vehicle ID, this time, the monitoring device 40 notifies the detection device 10 in the tire 4 to be monitored. When a sensor ID set in advance is transmitted and the sensor device 10 receives the sensor ID given to the sensor device 10 after transmitting the ACK signal, the detection device 10 transmits detection data with a predetermined header.

  Therefore, according to the monitoring system of the present embodiment, only the detection device 10 that is activated by the activation signal transmitted as the detection request signal from the monitoring device 40 side and in which the vehicle ID and the sensor ID respectively match the previously stored ID is included. Thus, the detection data is transmitted to the monitoring device 40, and each detection device 10 does not transmit the ACK signal or the detection data due to the activation signal or noise transmitted from the monitoring device 40 of the other vehicle. Therefore, according to the present Example, the tire state of the own vehicle can be satisfactorily monitored on the monitoring device 40 side.

  Further, since the detection device 10 is configured to generate a power supply voltage using a transmission signal (start signal) from the transmitter 30, it is not necessary to incorporate a battery for power supply in the tire 4, Since the monitoring device 40 operates each detection device 10 only when necessary, the operation of each detection device 10 is minimized and the power consumption of the in-vehicle battery consumed with the power supply to each detection device 10 The amount can be suppressed.

  By the way, in the monitoring system of the present embodiment, tire position data representing the relationship between the sensor ID, which is identification information for each tire 4, and the position of each tire 4 is stored in advance in the EEPROM 50a in the monitoring device 40. Thus, the control circuit 50 in the monitoring device 40 grasps the position of each detection device 10 in the vehicle based on the tire position data, and transmits the activation signal or the like to each detection device 10. Can be selected, and the position of the tire in which an abnormality in air pressure or temperature has occurred can be specified.

  However, since the position of the tire 4 in the vehicle is changed by so-called rotation as is well known, even if accurate tire position data is stored in the EEPROM 50a in the monitoring device 40 when the vehicle is shipped, the vehicle The tire position data may not match the actual tire position after shipment.

  Therefore, in the monitoring system of the present embodiment, immediately after the monitoring device 40 is started as the vehicle engine is started, the control circuit 50 in the monitoring device 40 executes the tire position registration process shown in FIG. The tire position data in the EEPROM 50a is updated.

Hereinafter, the tire position registration process will be described. This tire position registration process is a process for realizing the function as the tire position specifying means of the present invention.
As shown in FIG. 5, in this tire position registration process, first, in step 310, one of the arrangement positions of each tire 4 in the vehicle (for example, the left front wheel: FL) is selected as a registration target position of the sensor ID, In subsequent S320, an activation signal and a vehicle ID are transmitted from a transmitter 30 (for example, transmitter 30FL) corresponding to the registration target position.

  In the subsequent S330, the ACK signal is transmitted from the detection device 10 in the vicinity of the registration target position by determining whether or not the ACK signal is received by the receiving circuit 44 along with the transmission of the activation signal and the vehicle ID. If the receiving circuit 44 determines that the ACK signal has been received, the process proceeds to S340.

  In S340, among all the sensor IDs set for each tire 4 mounted on the vehicle, a sensor that has not been registered as a sensor ID for a specific tire position after the start of the tire position registration process. Get an ID. In subsequent S350, a sensor ID that has not been transmitted from the transmitter 30 at the registration target position is selected from the position unregistered sensor IDs acquired in S340, and the selected sensor ID is transmitted to the registration target position. In step S360, it is determined whether or not detection data is received by the receiving circuit 44 along with the transmission of the sensor ID.

  That is, if there is a detection device 10 to which the sensor ID selected and transmitted in S350 is provided in the vicinity of the transmitter 30 at the registration target position, detection data is transmitted from the detection device 10, so in S360 The receiving circuit 44 determines whether or not the detection data transmitted from the detection device 10 is received, thereby determining whether or not the sensor ID selected in S350 exists in the vicinity of the registration target position. It is.

  If it is determined in S360 that the detection data from the detection apparatus 10 has been received, the process proceeds to S370, and the sensor ID selected and transmitted in S350 is replaced with the sensor ID at the current registration target position. After storing in the memory (RAM) as registration candidates, the process proceeds to S380. If it is determined in S360 that the detection data from the detection apparatus 10 has not been received, the process proceeds to S380.

  Next, in S380, it is determined whether or not all sensor IDs acquired in S340 have been transmitted in the process of S350, and if all sensor IDs have not been transmitted, the process proceeds to S350 again and has not been transmitted. If all sensor IDs are transmitted, the process proceeds to S390.

  In S390, it is determined whether there is one or a plurality of sensor IDs (storage IDs) stored in the memory as sensor ID registration candidates at the current registration target position in S370. If there is one, in S400, the storage ID is registered in the EEPROM 50a as the sensor ID of the tire 4 (in other words, the detection device 10) arranged at the current registration target position, and then the process proceeds to S420. On the other hand, when it is determined that there are a plurality of storage IDs, the sensor ID of the detection device 10 arranged at the current registration target position cannot be specified, and the process directly proceeds to S420.

  Next, in S420, it is determined whether or not the series of processing in S320 to S400 has been performed for all the arrangement positions of the tires 4 in the vehicle (that is, all registration target positions). If it is determined in S420 that the processing for all registration target positions has not been completed, the registration target position of the sensor ID is determined in S430 for tires that have not performed the series of processes in S320 to S400. After changing to the arrangement position, the process proceeds to S320, and conversely, if it is determined in S420 that the processing for all the registration target positions has been completed, the process proceeds to S440.

  Next, in S440, there is a plurality of sensor IDs stored in the memory as registration candidates for the registration target position whether or not there is a registration target position with no sensor ID registered. It is determined whether there is a registration target position that has not been registered.

  If it is determined in S440 that there is no registration target position with no sensor ID registered, the sensor IDs are registered for all the registration target positions, so the process is terminated as it is. If it is determined in S440 that there is a registration target position that has not been registered with a sensor ID, the process proceeds to S450, and a sensor ID that has already been registered in the EEPROM 50a (registered ID) and a registration that has not been registered with a sensor ID. Based on the sensor ID stored in the memory as a sensor ID registration candidate at the target position, the sensor ID at the registration target position where the sensor ID is not registered is determined and registered in the EEPROM 50a, and then the process ends.

  Thus, in the monitoring system of the present embodiment, the control circuit 50 in the monitoring device 40 updates the tire position data in the EEPROM 50a by executing the tire position registration process immediately after starting up itself. ing.

  Therefore, according to the monitoring system of the present embodiment, even if the position of each tire 4 in the vehicle is changed by rotation, the tire position data in the EEPROM 50a is updated according to the position change, and The tire condition can always be accurately monitored.

  In the tire position registration process shown in FIG. 5, the processes in S440 and S450 are detections in which detection data is returned when unregistered sensor IDs are sequentially transmitted from the transmitter 30 arranged at the registration target position. This process is executed when a plurality of apparatuses 10 exist. As in this embodiment, one tire 4 is arranged on each of the front, rear, left and right sides of the vehicle, and a transmitter 30 is arranged for each tire 4. The transmission signal from the transmitter 30 is extremely unlikely to reach the plurality of detection devices 10, and the problem that the transmission signal from the transmitter 30 reaches the plurality of detection devices 10 occurs. This is when the transmission power of one of the plurality of transmitters 30 is significantly increased from the design time for some reason.

  For this reason, in S450, if a sensor ID that has already been registered in the EEPROM 50a is removed from a plurality of sensor IDs that are registration candidates at a registration target position where the sensor ID is not registered, the sensor ID The sensor ID to be registered can be determined for the registration target position where the ID is not registered.

  However, for example, in the vehicle of the present embodiment, the detection device 10 is also incorporated in the spare tire housed in the trunk room at the rear of the vehicle, and the transmitter 30 is disposed in the vicinity of the spare tire housing part. In the EEPROM 50a in the monitoring device 40, as shown by a dotted line in FIG. 4, the spare tire and the sensor ID (E) as the identification information are stored in association with each other. When the position registration process is executed, the transmission signal from the transmitter 30 reaches the plurality of tires 4 when searching for the sensor IDs of the left and right rear wheels and the spare tire by a series of processes of S340 to S380. It is conceivable that detection data is transmitted from the detection device 10 in the inside.

  Therefore, in such a monitoring system, when executing S450, there are a plurality of registration target positions that have not been registered with the sensor ID. In S450, transmission from each transmitter 30 corresponding to each of these registration target positions is performed. If a tire position capable of receiving a signal is registered in advance, and a sensor ID corresponding to each tire position is determined based on the registration information and the type of sensor ID actually acquired at each registration target position. Good.

As mentioned above, although one Example of this invention was described, this invention is not limited to the said Example, A various aspect can be taken in the range which does not deviate from the summary of this invention.
For example, in the above embodiment, the detection device 10 is provided with the reception antenna 12 for receiving the LF signal and the transmission antenna 26 for transmitting the RF signal in the UHF band, and the monitoring device 40 is provided with the transmission antenna 32 for transmitting the LF signal and the UHF. A receiving antenna 42 for receiving the RF signal of the band, and using each of these transmission / reception antennas, using the RF signal of the UHF band to transmit the detection data from the detection device 10 to the monitoring device 40, The transmission of the detection request signal from the monitoring device 40 to the detection device 10 has been described as using an LF signal in the LF band that can supply power to the detection device 10, but detection from the detection device 10 to the monitoring device 40 is performed. The LF signal may also be used for data transmission.

  That is, as illustrated in FIG. 6, each detection device 10 includes a drive circuit 29 that transmits detection data from the reception antenna 12 by driving the reception antenna 12 instead of the transmission circuit 28 and the transmission antenna 26 of the above embodiment. In the vicinity of each detection device 10, a transmitter / receiver 31 capable of transmitting / receiving an LF signal via a transmission antenna 32 is provided instead of the transmitter 30, and the monitoring device 40 further includes the reception of the above embodiment. Instead of the antenna 42 and the reception circuit 44, a detection circuit 10 is provided by processing a reception signal from the amplification circuit 36 for amplification of reception signals provided in the transmitter / receiver 31 to restore detection data. All data transmission and reception between the monitoring device 40 and the monitoring device 40 may be performed using the LF signal via the transceiver 31.

  On the other hand, in the above embodiment, the monitoring device 40 side can acquire detection data representing the tire state of each tire 4 while grasping the tire position from the plurality of detection devices 10 mounted on the host vehicle. The monitoring device 40 has been described as transmitting a detection request signal including a start signal, a vehicle ID, and a sensor ID to each detection device 10 via a transmitter disposed in the vicinity of each detection device 10. In order to transmit detection data from a specific detection device 10 whose tire position is known by transmitting a detection request signal, a transmitter 30 is necessarily provided for each detection device 10 (in other words, for each tire 4). The detection request signal may be transmitted from the reception antenna 42 by using the reception antenna 42 as a transmission antenna.

  However, in this case, since the frequency of a signal that can be transmitted and received by the receiving antenna 42 is in the UHF band, it is necessary to use a signal in the UHF band as the detection request signal. In this case, since the UFH band RF signal cannot supply power to the detection device 10, the detection device 10 needs to incorporate a battery.

  Next, in the above embodiment, when a sensor ID is assigned to each detection device 10 and a detection request signal is transmitted to each detection device 10 from the monitoring device 40 side, the detection request signal is specific to the detection request signal. The sensor ID (tire identification information) is given, and the detection data is transmitted from the detection device 10 of the tire 4 arranged at a desired location. However, as in the above embodiment, each detection device 10 When the transmitter 30 dedicated to each detection device 10 is provided in the vicinity of each of the detection devices 10 and each transmission by adjusting the transmission power of each transmitter 30 and the directivity characteristics of the transmission antenna, setting the frequency of the transmission signal, and the like. If the machine 30 is made to correspond one-to-one, detection data can be acquired from the detection device 10 arranged at a specific place without giving a sensor ID to each detection device 10.

It is explanatory drawing showing the structure of the whole monitoring system of an Example. It is a block diagram showing the structure of a detection apparatus, a transmitter, and a monitoring apparatus. It is a flowchart showing the tire condition monitoring process and detection data transmission process which are each performed by the monitoring apparatus and a detection apparatus for tire condition monitoring. It is explanatory drawing showing the transmission / reception data between the tire position data memorize | stored in the monitoring apparatus and monitoring apparatus-detection apparatus. It is a flowchart showing the tire position registration process performed in the monitoring apparatus in order to update the tire position data of FIG. It is a block diagram showing the other structural example of the monitoring system.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 4 ... Tire, 10 ... Detection apparatus, 12 ... Reception antenna (LF), 14 ... Power supply circuit, 16 ... Reception circuit, 20 ... Control circuit, 20a ... EEPROM, 22 ... Pressure sensor, 24 ... Temperature sensor, 26 ... Transmission antenna (RF), 28 ... transmission circuit, 29 ... drive circuit, 30 ... transmitter, 31 ... transceiver, 32 ... transmitting antenna (LF), 34 ... drive circuit, 36 ... amplifier circuit, 40 ... monitoring device, 42 ... receive Antenna (RF), 44, 48 ... receiving circuit, 50 ... control circuit, 50a ... EEPROM, 60 ... notification device.

Claims (3)

A plurality of detection devices that are each incorporated in a plurality of tires of a vehicle, detect a tire condition including at least the air pressure of each tire, and transmit the detection results wirelessly;
A monitoring device mounted on a vehicle and monitoring the tire condition of each tire by receiving detection results transmitted from the detection devices, and notifying the occupant of the monitoring results;
A vehicle tire condition monitoring system comprising:
The monitoring device wirelessly transmits a detection request signal including vehicle identification information unique to the vehicle to each of the detection devices, and then receives a detection result transmitted from each of the detection devices. , Monitor the tire condition of each tire,
When each of the detection devices receives the detection request signal transmitted from the monitoring device, whether or not the vehicle identification information given to the detection request signal matches the vehicle identification information registered in advance in the detection device. When the vehicle identification information matches, the tire condition detection system transmits the tire condition detection result. When transmitting the detection request signal, the monitoring device wirelessly transmits one of the tire identification information set for each tire in addition to the vehicle identification information, and then transmits the tire identification information to the tire identification information. By receiving the detection result transmitted from the detection device in the corresponding tire, the tire condition is monitored for each tire,
When each of the detection devices receives the detection request signal transmitted from the monitoring device, the vehicle identification information and the tire identification information are respectively registered in advance in the vehicle identification information and the tire identification information in the detection device. 2. The vehicle according to claim 1, wherein it is determined whether or not the information coincides with each other, and when the respective pieces of identification information coincide with each other, the tire state is detected and the detection result is transmitted. Tire condition monitoring system. The monitoring device
A plurality of transmission means respectively disposed in the vicinity of each tire;
Under the predetermined conditions set in advance, the transmission means transmits the tire identification information of each tire mounted on the vehicle in turn from the transmission means, and then responds from the detection device corresponding to the tire identification information. Tire position specifying means for specifying tire identification information of a tire located in the vicinity of each of the transmission means by determining whether or not there is,
When monitoring the tire condition, the detection request signal including the tire identification information of each tire based on the relationship between the position of each transmitting means specified by the tire position specifying means and the tire identification information, 3. The tire condition monitoring system for a vehicle according to claim 2, wherein the tire condition of each tire is monitored by sequentially transmitting it via a transmission means corresponding to the tire identification information.

Images