JP2010143485A - Wheel position specifying system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To avoid the event that a receiving device cannot receive electric waves from a transmitting device depending on the rotating angle of a wheel to an axle. <P>SOLUTION: This wheel position specifying system 200 executes wheel position specifying processing. Herein, a transceiver 16 is provided on each wheel 14 for transmitting identifying information for the wheel 14. A receiver 20 is provided on a vehicle body 12 on which each wheel 14 is mounted, for receiving the identifying information. A wheel position specifying means specifies the position of the wheel 14 on which the transceiver 16 transmitting the identifying information is provided, in accordance with the identifying information. A control means controls the wheel position specifying processing and determines whether the wheel position specifying means specifies the position of each wheel 14 or not. A vehicle travel detecting means detects the travel of the vehicle 10. When determining that the wheel position specifying means does not specify the position of each wheel 14 at stopping the vehicle, the control means executes the wheel position specifying processing again after the vehicle travel detecting means detects the travel of the vehicle 10. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a wheel position specifying system.

  In recent years, in order to realize safer vehicle driving, tire pressure monitoring system (TPMS: Tire Pressure Monitoring System) has been developed to notify the driver by wirelessly transmitting information such as tire pressure and temperature to the vehicle body. It has been. In the tire pressure monitoring system, each wheel is provided with a wheel information detection unit that detects wheel information such as tire pressure. The control unit on the reception side provided in the vehicle body receives wheel information from the wheel information detection unit after specifying the position of the wheel information detection unit on which wheel.

Patent Document 1 discloses a vehicle information processing device that identifies a transmission device that is a transmission source of a signal received by a reception device mounted on a vehicle body.
JP 2006-107253 A

  By the way, in the technique disclosed in Patent Document 1, the transmission device is mounted on each wheel. At this time, depending on the rotation angle of the wheel with respect to the axle, the receiving device may not be able to receive radio waves from the transmitting device. If the communication between the receiving device and the transmitting device is impossible, the vehicle information processing device cannot specify the position of each wheel. Further, if the vehicle information processing apparatus repeatedly executes the wheel position specifying process until the position of each wheel is specified, the transmitting apparatus continues to transmit radio waves even though the receiving apparatus cannot receive radio waves from the transmitting apparatus. Thus, useless power is consumed.

  The present invention has been made in view of such a situation, and an object of the present invention is to identify a wheel on which a transmitter is provided among a plurality of wheels provided on a vehicle while suppressing unnecessary power consumption. It is to provide.

  In order to solve the above-described problems, a wheel position specifying system according to an aspect of the present invention is a wheel position specifying system that executes a wheel position specifying process, and is a transmitter that is provided in each wheel and transmits wheel identification information. And a wheel position specification that specifies a position of a wheel provided in a vehicle main body to which each wheel is mounted and that receives identification information and a transmitter that transmits identification information based on the identification information. Means, control means for controlling the wheel position specifying process, and determining whether the wheel position specifying means specified the position of each wheel, and vehicle running detecting means for detecting the running of the vehicle. When it is determined that the wheel position specifying means does not specify the position of each wheel when the vehicle is stopped, the control means re-executes the wheel position specifying process after the vehicle running detection means detects the vehicle running. According to this aspect, even when the wheel position cannot be specified when the vehicle is stopped, the process of specifying the position of each wheel can be re-executed after the vehicle moves and the wheel rotation angle changes.

  The control means may execute the wheel position specifying process a predetermined number of times, and stop the wheel position specifying process if the position of each wheel cannot be specified. Thereby, the power consumption concerning a wheel position specific process in a wheel position specific system can be suppressed.

  The transmitter transmits the wheel state information detected by the sensor provided on the wheel to the receiver at a predetermined cycle separately from the transmission process in the wheel position specifying process, and the control means includes the wheel position specifying means for each wheel. If the position is not specified and the receiver receives wheel state information, the wheel position specifying process may be re-executed. Thus, the wheel position specifying process can be re-executed when the communication status is good, and the possibility of completing the wheel position specifying process can be increased.

  The wheel position specifying means may distinguish the traveling wheel from the spare tire based on an output of an acceleration sensor provided on each wheel. The control means does not execute the wheel position specifying process until the spare tire is specified in the vehicle including the spare tire. Thereby, the power consumption concerning a wheel position specific process can be suppressed more.

  ADVANTAGE OF THE INVENTION According to this invention, the technique which specifies to which wheel the transmitter is provided among several wheels provided in a vehicle can be provided, suppressing unnecessary power consumption.

  The vehicle of the embodiment includes a wheel state detection device that detects wheel states such as tire air pressure and tire air temperature. In the wheel state detection device, a transmitter provided on a wheel transmits wheel identification information and wheel state information detected by wheel sensors to a receiver provided on the vehicle body at a predetermined communication cycle. This communication cycle is, for example, 1 minute. An electronic control unit (hereinafter referred to as “ECU”) detects whether there is an abnormality in the air pressure or temperature of the wheel based on the received wheel state information. If the ECU detects an abnormality in the wheel, the alarm is transmitted to the driver by an alarm device. As a premise, the ECU cannot identify which wheel has an abnormality unless the correspondence between the wheel identification information transmitted by the transmitter and the position of the wheel can be identified. Therefore, the ECU needs to specify the position of the wheel in advance as a premise for performing the wheel state detection process.

  The wheel position specifying system according to the embodiment attempts to specify the position of each wheel while suppressing unnecessary power consumption. Specifically, the wheel position specifying system first executes a wheel position specifying process for specifying the position of the wheel provided with the transmitter that transmitted the wheel identification information before the vehicle starts when the engine is started. If the position of each wheel can be specified before the vehicle starts traveling, it is possible to appropriately detect the wheel state during vehicle traveling, which is desirable. However, depending on the rotation angle of the wheel when the vehicle is stopped, the transmitter and the receiver may not be able to communicate and the wheel position specifying process may not be completed. In addition, the rotation angle of a wheel means the rotation angle with respect to the axle of the wheel with which the vehicle main body was mounted | worn. If the transmitter continues to transmit the wheel identification information even though the transmitter and the receiver cannot communicate, unnecessary power consumption of the transmitter occurs. Therefore, if the wheel position specifying system according to the embodiment cannot specify the position of each wheel when the vehicle is stopped, the wheel position specifying process is temporarily interrupted and triggered by the detection of the vehicle traveling again. The wheel position specifying process is executed. Thereby, the position of the wheel can be specified while suppressing unnecessary power consumption.

  FIG. 1 is an overall configuration diagram of a wheel position specifying system 200 according to the embodiment. The vehicle 10 includes a right front wheel 14FR, a left front wheel 14FL, a right rear wheel 14RR, a left rear wheel 14RL, a spare wheel 14SP (hereinafter collectively referred to as “wheel 14” as necessary), and a vehicle body 12.

  The right front wheel 14FR, the left front wheel 14FL, the right rear wheel 14RR, and the left rear wheel 14RL are mounted on the vehicle main body 12 and function as traveling wheels that make the vehicle travel by contacting and rotating on the road surface. The spare wheel 14SP is attached to the vehicle main body 12, for example, below the trunk room, etc. in preparation for an abnormality occurring in any of these traveling wheels. The spare wheel 14SP including the transceiver 16SP and the wheel sensors 28SP is referred to as a ground spare tire.

  Each wheel 14 has a tire and a wheel. A wheel rim formed in a cylindrical shape is provided on the outer periphery of the wheel, and a tire is assembled on the outer periphery of the wheel rim. Thus, a tire air chamber is formed in a region surrounded by the inside of the tire and the outer periphery of the wheel rim.

  A transmitter / receiver 16FR, a transmitter / receiver 16FL, a transmitter / receiver 16RR, a transmitter / receiver 16RL, and a transmitter / receiver 16SP are provided corresponding to each of the wheels 14 (hereinafter collectively referred to as “transmitter / receiver 16” as necessary). The transceiver 16 may have a main body and be provided on a tire valve. The main body has a battery and a base inside. The battery supplies power to a base processing device or the like. For this reason, the transceiver 16 can transmit a wheel signal without receiving power supply from the vehicle body 12. The main body is fixed to one end of the tire valve. The transceiver 16 is attached to the wheel 14 by fixing the tire valve to the wheel rim of the wheel.

  Corresponding to each of the wheels 14, wheel sensors 28FR, wheel sensors 28FL, wheel sensors 28RR, wheel sensors 28RL, and wheel sensors 28SP are provided (hereinafter referred to as “ Wheel sensors 28 "). The wheel sensors 28 include a pressure sensor that detects the air pressure in the tire, a temperature sensor that detects the temperature in the tire chamber, an acceleration sensor that detects the angular velocity of the rotating wheel, and the like. The wheel sensors 28 are connected to the transceiver 16.

  In the wheel position specifying process, the transmitter / receiver 16 transmits the wheel identification information of the wheel 14 in response to an instruction from the ECU 100. The transmitter / receiver 16 transmits the wheel state information and the wheel identification information detected by the wheel sensors 28 provided on the wheel 14 to the receiver 20 at a predetermined cycle, separately from the transmission process in the wheel position specifying process.

  Transmitter 18F and transmitter 18R (hereinafter collectively referred to as “transmitter 18” as necessary) are provided on the front wheel side and the rear wheel side of vehicle body 12. The transmitter 18F is disposed at a position where the distance from the right front wheel 14FR and the distance from the left front wheel 14FL are different, and the transmitter 18R is a position where the distance from the right rear wheel 14RR is different from the distance from the left rear wheel 14RL. Placed in. For example, the distance from the transmitter 18F to the right front wheel 14FR is longer than the distance from the transmitter 18F to the left front wheel 14FL. The transmitter 18 wirelessly transmits a reply request signal to the transceiver 16. The number of transmitters 18 may be one, in which case the distance from the right front wheel 14FR, the distance from the left front wheel 14FL, the distance from the right rear wheel 14RR, and the distance from the left rear wheel 14RL, respectively. Arranged at different positions.

  The receiver 20 is provided in the vehicle main body 12 and receives the wheel signal transmitted from the transceiver 16. The wheel signal transmitted from the transceiver 16 includes a response signal responding to the reply request signal transmitted from the transmitter 18 and a wheel state signal transmitted periodically. The “response signal” includes the wheel identification information of the wheel 14 and the reception strength of the reply request signal transmitted from the transmitter 18. The reception strength of the reply request signal may be an electric field strength indicating the strength of the radio wave of the reply request signal received by the transceiver 16. The “wheel state signal” includes wheel identification information of the wheel 14 and wheel state information detected by the wheel sensors 28. Receiver 20 is connected to ECU 100. The receiver 20 supplies the received wheel signal to the ECU 100.

  The vehicle body sensors 22 are provided in the vehicle main body 12 and connected to the ECU 100. The vehicle body sensors 22 include an acceleration sensor that detects the acceleration of the vehicle 10, a yaw rate sensor that detects the yaw rate of the vehicle 10, and the like. The vehicle body sensors 22 supply the detected vehicle body state information to the ECU 100.

  The alarm device 24 is connected to the ECU 100 and issues an alarm to the driver of the vehicle 10. For example, the alarm device 24 may be a display or a buzzer.

  The ignition switch 26 is connected to the ECU 100 and is provided to start an engine (not shown). That is, the ignition switch 26 switches the engine ON / OFF.

  The ECU 100 is configured as a microprocessor including a CPU, an arithmetic unit for performing calculations by the microcomputer, a ROM for storing various processing programs, and temporarily storing data and programs for data storage and program execution. It has a RAM used as a work area, an input / output port for transmitting and receiving various signals, and the like.

  A wheel position specifying system 200 that executes wheel position specifying processing includes a transmitter / receiver 16, a wheel sensor 28, a transmitter 18, a receiver 20, a vehicle body sensor 22, an alarm device 24, an ignition switch 26, and an ECU 100. . The transmitter 18 transmits a reply request signal to the transceiver 16 in response to an instruction from the ECU 100. When receiving the reply request signal from the transmitter 18, the transmitter / receiver 16 transmits a response signal to the receiver 20. The ECU 100 specifies the position of the wheel 14 based on the reception intensity of the reply request signal included in the response signal and the wheel identification information. Specifically, the ECU 100 identifies the left wheel or the right wheel depending on the strength of reception of the reply request signal. Further, the transmitter 18F and the transmitter 18R transmit a reply request signal at different timings, and the ECU 100 identifies the front wheel or the rear wheel based on the timing of the received response signal. The wheel position specifying system 200 also functions as a wheel state detection device that detects wheel state information such as tire air pressure and tire air chamber temperature.

  By the way, depending on the rotation angle of the wheel 14, the transmitter 18 and the transmitter / receiver 16 may not be able to communicate with each other, or the transmitter / receiver 16 and the receiver 20 may not be able to communicate with each other. May not reach the other party. The relationship between the rotation angle of the wheel 14 and the communication state between the transceiver 16 and the receiver 20 will be specifically described below.

  FIG. 2 shows the relationship between the rotation angle of the wheel 14 and the communication state between the transceiver 16 and the receiver 20. FIG. 2A shows the relationship between the rotation angle of the wheel 14 and the intensity when the receiver 20 receives the radio wave transmitted from the transceiver 16. FIG. 2B shows the rotation angle of the communication failure state of the wheel 14.

  The vertical axis in FIG. 2A indicates the radio wave intensity when received by the receiver 20, and the horizontal axis indicates the rotation angle of the wheel 14. If the signal strength is less than Th, the reception state of the receiver 20 is poor. The relationship between the rotation angle of the wheel 14 and the communication state between the transceiver 16 and the receiver 20 varies depending on factors such as the tire of the wheel 14, the type of wheel, and the vehicle type.

  FIG. 2B is a development of the relationship shown in FIG. A black region in FIG. 2B indicates a rotation angle that causes communication failure. If the rotation angle of the wheel 14 is in the rotation angle indicated in the black region, the receiver 20 cannot receive a response signal transmitted from the transmitter / receiver 16 of the wheel 14, and the ECU 100 determines the position of the wheel 14. Cannot be specified. In addition, the communication state between the transmitter 18 and the transmitter / receiver 16 may cause a communication failure depending on the rotation angle of the wheel 14, and the reply request signal may not reach the transmitter / receiver 16.

  FIG. 3 shows a functional configuration of the ECU 100 according to the embodiment. The ECU 100 includes a wheel signal acquisition unit 30, a wheel state detection unit 32, a wheel position specification unit 34, a wheel identification information holding unit 36, a non-reception alarm unit 38, a control unit 40, a travel detection unit 42, And an instruction unit 44.

  The wheel signal acquisition unit 30 acquires the wheel signal received by the receiver 20. The wheel signal acquisition unit 30 supplies the acquired wheel signal to at least one of the wheel state detection unit 32, the wheel position specification unit 34, and the non-reception alarm unit 38.

  The wheel position specifying unit 34 specifies the position of the wheel 14 provided with the transceiver 16 that has transmitted the wheel identification information, based on the wheel identification information included in the response signal. Here, the wheel position specifying process will be described. First, when the control unit 40 determines to execute the wheel position specifying process, the instruction unit 44 instructs the transmitter 18 to transmit a reply request signal. The transmitter 18F and the transmitter 18R receive an instruction from the instruction unit 44, and transmit a reply request signal at different timings. When each of the front wheel and rear wheel transceivers 16 receives the reply request signal, it measures the radio field intensity, generates a response signal including the wheel identification information and the reception intensity, and transmits it. The wheel position specifying unit 34 specifies whether the response signal is transmitted from the front wheel or the rear wheel according to the timing of the response signal received by the receiver 20.

  Further, the wheel position specifying unit 34 compares the reception intensity transmitted from the transmitter / receiver 16 and specifies whether the wheel identification information transmitted from the transmitter / receiver 16 corresponds to the left wheel or the right wheel. Specifically, the transmitter / receiver 16FL and the transmitter / receiver 16FR that have received the reply request signal from the transmitter 18F transmit the response signal including the reception strength of the received reply request signal. This reception intensity is determined according to the distance from the transmitter 18 to the transmitter / receiver 16. The reception intensity of the left wheel transmitter / receiver 16FL close to the transmitter 18F is larger than the reception intensity of the right wheel transmitter / receiver 16FR far from the transmitter 18F. Therefore, the wheel position specifying unit 34 compares the two received intensities transmitted from the transceiver 16FL and the transceiver 16FR, and indicates the larger received intensity if the difference between the two received intensities is a predetermined value or more. The wheel identification information of the transmitter / receiver 16FL is specified as the left wheel, and the wheel identification information of the transmitter / receiver 16FR indicating the smaller reception intensity is specified as the right wheel. As described above, the wheel position specifying unit 34 specifies all positions of each wheel 14 by combining the front and rear wheel specifying method and the left and right wheel specifying method.

  If the position of all the wheels 14 is specified, the wheel position specifying unit 34 generates a completion flag indicating that the wheel position specifying process has been completed. The wheel position specifying process means that each transmitter 18 transmits a reply request signal once, and the transmitter / receiver 16 sends a response signal once in response to the start of execution of the wheel position specifying process in the control unit 40. This means one trial until the wheel position specifying unit 34 tries to specify the position of each wheel 14 based on the response signal.

  Further, the wheel position specifying unit 34 distinguishes between the traveling wheel and the spare wheel 14SP based on the output of the acceleration sensor of the wheel sensors 28 while the vehicle is traveling. While the vehicle is running, a wheel state signal including acceleration information detected by the acceleration sensor is transmitted from each transceiver 16 at a predetermined communication cycle. Since the spare wheel 14SP does not rotate during traveling of the vehicle, the output of the acceleration sensor of the wheel sensors 28SP hardly changes. On the other hand, the output of the acceleration sensor of the wheel sensors 28 for the traveling wheels changes greatly during traveling of the vehicle. The wheel position specifying unit 34 specifies that the wheel identification information included in the wheel state signal together with the wheel state information indicating the output of the acceleration sensor having almost no change corresponds to the spare wheel 14SP when the traveling of the vehicle 10 is detected. To do. The wheel position specifying unit 34 may receive information related to vehicle travel from the travel detection unit 42.

  From the above, the wheel position specifying unit 34 specifies the position of each wheel 14, associates the wheel identification information with the position of the wheel 14, and causes the wheel identification information holding unit 36 to hold the wheel identification information. The wheel position specifying unit 34 may use another known method for specifying the position of each wheel 14. For example, the wheel identification information transmitted from the transceiver 16 may include information that can identify the position of the wheel such as the right front wheel in advance, and the wheel position specifying unit 34 determines the position of each wheel 14 based on the information. May be specified.

  The wheel state detection unit 32 detects the state of each wheel 14 from the wheel state information received from the wheel signal acquisition unit 30. If the wheel state detection unit 32 detects an abnormality in the air pressure or temperature of the wheel 14, the wheel state detection unit 32 transmits the abnormality to the driver via the alarm device 24. The wheel state detection unit 32 detects which wheel 14 is abnormal based on the information specifying the position of the wheel 14 held in the wheel identification information holding unit 36.

  The non-reception alarm unit 38 generates non-reception information when the receiver 20 has not received the wheel state signal periodically transmitted from the transceiver 16. The non-reception alarm unit 38 generates non-reception information if the receiver 20 cannot receive the wheel state signal from at least one of the transceivers 16. For example, when the wheel state signal is transmitted at a cycle of one minute, the non-reception alarm unit 38 determines whether the wheel signal acquisition unit 30 has acquired a new wheel state signal every minute. And the non-reception warning part 38 produces | generates non-reception information, if the wheel signal acquisition part 30 has not acquired a new wheel state signal. If unreceived information is not generated, communication between the transceiver 16 and the receiver 20 is established within one minute, which is the communication cycle of the wheel state signal, and there is a high possibility that the communication status is good. The non-reception alarm unit 38 may issue a non-reception alarm via the alarm device 24 when the receiver 20 has not continuously received the wheel state signal from the transceiver 16 for, for example, 20 minutes or more. .

  The travel detection unit 42 detects the travel of the vehicle 10. Specifically, the travel detection unit 42 detects the travel of the vehicle 10 based on the output of the acceleration sensor of the wheel sensors 28 or the acceleration sensor of the vehicle body sensor 22.

  The control unit 40 controls the wheel position specifying process, and determines whether or not the wheel position specifying unit 34 has specified the position of each wheel 14. If the wheel position specifying process is not completed, that is, if the wheel position specifying unit 34 cannot specify the position of each wheel 14, the control unit 40 executes the wheel position specifying process at most a predetermined number of times. The wheel position specifying process may be stopped assuming that the position specifying process is incomplete. Thereby, compared with the case where a wheel position specific process is repeatedly performed until a wheel position specific process is completed, the power consumption concerning a wheel position specific process can be suppressed. Since the transceiver 16 is battery-driven, it is preferable to suppress the power consumption of the transceiver 16.

  The control unit 40 executes the wheel position specifying process when the ignition switch 26 is turned from OFF to ON, that is, when the start of the vehicle is detected when the vehicle is stopped. When it is determined that the wheel position specifying unit 34 has not specified the position of each wheel when the vehicle is stopped, the control unit 40 re-executes the wheel position specifying process after the travel detecting unit 42 detects the travel of the vehicle. To do. As a result, even if the wheel position specifying process is not completed when the vehicle is stopped, the wheel position specifying process can be re-executed after the vehicle 10 moves and the rotation angle of the wheel 14 is changed. Can increase the possibility of completing.

  If the wheel position specifying unit 34 has not specified the position of each wheel 14 and the receiver 20 has received a wheel state signal, the control unit 40 re-executes the wheel position specifying process. The control unit 40 determines whether or not the receiver 20 has received a wheel state signal based on whether or not unreceived information is generated in the unreceived alarm unit 38. Here, factors other than the rotation angle of the wheel 14 that the wheel position specifying process is not completed are predicted. For example, if an object that generates strong radio waves temporarily exists around the vehicle 10, the wheel position specifying process may not be completed. If unreceived information is not generated, communication from the transmitter / receiver 16 to the receiver 20 is good at least before the communication cycle of the wheel state signal, and if the wheel position specifying process is performed again at this time, the wheel position The possibility of completing the specific process can be increased.

  When the wheel position specifying unit 34 does not specify the position of each wheel 14, the control unit 40 may re-execute the wheel position specifying process every time a predetermined time elapses. Here, the number of times the wheel position specifying process is re-executed every elapse of a predetermined time may be a predetermined number of loops. That is, the execution of the predetermined set number of times of the wheel position specifying process described above is set as one set, and this one set of wheel position specifying process is repeated a predetermined number of loops. For example, if the predetermined number of times is set to 10, the predetermined time is set to 20 minutes, and the predetermined number of loops is set to 3, the control unit 40 first executes the wheel position specifying process 10 times at the maximum when the vehicle stops, and starts running. The wheel position specifying process executed 10 times every 20 minutes from the time is repeated up to 3 times. In addition, if the wheel position specifying process is completed during the process, the control unit 40 ends the process at that time. By repeating the wheel position specifying process every predetermined time by a predetermined number of loops, the possibility of retrying the wheel position specifying process and completing the wheel position specifying process can be increased. Note that the control unit 40 determines whether or not the receiver 20 receives a wheel state signal every predetermined time. When the receiver 20 receives a wheel state signal, the control unit 40 re-executes the wheel position specifying process. You can repeat it. Thereby, when the possibility of completing the wheel position specifying process is high, the wheel position specifying process can be retried.

  Moreover, the control part 40 does not need to perform a wheel position specific process in the vehicle 10 provided with the spare wheel 14SP until it detects driving | running | working of the vehicle 10, ie, until a grand spare tire is specified. Whether or not the vehicle 10 has a ground spare tire may be set in the ECU 100 in advance. When the vehicle 10 has a ground spare tire, the transmitter / receiver 16SP responds to a reply request signal transmitted from the transmitter 18R, and therefore the ground spare tire becomes an obstacle to the process of specifying the position of the rear wheel. There is. Therefore, when the vehicle 10 has a ground spare tire, the wheel position specifying process is not executed until the traveling of the vehicle 10 is detected and the ground spare tire is specified, thereby reducing the power consumption for the wheel position specifying process. It can be suppressed more. If it determines with performing the wheel position specific process, the control part 40 will supply the determination result to the instruction | indication part 44. FIG.

  The instruction unit 44 instructs the transmitter / receiver 16 to transmit the wheel identification information according to the determination result by the control unit 40. Specifically, the instruction unit 44 receives the determination result that the wheel position specifying process is to be executed from the control unit 40, and instructs the transmitter 18 that the transmitter / receiver 16 transmits a response signal. The transmitter 18F and the transmitter 18R alternately transmit a reply request signal in response to an instruction from the instruction unit 44, and the transceiver 16 transmits a response signal in response to the reply request signal.

  FIG. 4 is a flowchart showing processing for specifying the position of each wheel 14 according to the embodiment. First, the control unit 40 determines whether the ignition switch (IG) 26 is turned on (S10). If it is determined that the ignition switch 26 is not turned on (N in S10), the control unit 40 ends the process.

  If it determines with the ignition switch 26 having been turned ON (Y of S10), the control part 40 will determine whether the vehicle 10 has a ground spare tire (S12).

  If it determines with the vehicle 10 not having a grand spare tire (N of S12), the control part 40 will start execution of a wheel position specific process (S14). Here, the wheel position specifying process may be executed a predetermined number of times at maximum.

  The control unit 40 determines whether or not the wheel position specifying process has been completed, that is, whether or not the wheel position specifying unit 34 has specified all the positions of the wheels 14 (S16). If it determines with the control part 40 having completed the wheel position specific process (Y of S16), a process will be complete | finished.

  If it is determined that the wheel position specifying process has not been completed (N in S16), the control unit 40 determines whether the traveling detection unit 42 has detected the traveling of the vehicle 10 (S18). If it is determined that the vehicle 10 has a ground spare tire (Y in S12), the control unit 40 determines whether the travel detection unit 42 has detected the travel of the vehicle 10 (S18). The control unit 40 determines until the traveling detection unit 42 detects the traveling of the vehicle 10 (N in S18). If it determines with the driving | running | working detection part 42 having detected driving | running | working of the vehicle 10 (Y of S18), the control part 40 will perform a wheel position specific process (S20). Thereby, a wheel position specific | specification process can be performed in the state which the rotation angle of the wheel 14 changed. In addition, it is possible to specify the ground spare tire when the vehicle is traveling and to execute the wheel position specifying process on the traveling wheels excluding the ground spare tire. Here, the wheel position specifying process may be executed a predetermined number of times at maximum.

  The control unit 40 determines whether the wheel position specifying process is completed (S22). If it is determined that the wheel position specifying process has been completed (Y in S22), the control unit 40 ends the process.

  If it is determined that the wheel position specifying process has not been completed (N in S22), the control unit 40 sets the loop count i to 0 (S24). The control unit 40 determines whether or not unreceived information indicating that the receiver 20 has not received the wheel state signal has been generated (S26). That is, the control unit 40 determines whether or not the receiver 20 has received a wheel state signal. If it is determined that the unreceived information has been generated (Y in S26), the control unit 40 repeats the process of determining whether the unreceived information has been generated every predetermined time.

  If it determines with the non-received information not being produced | generated (N of S26), the control part 40 will perform a wheel position specific process (S28). Thereby, the possibility of completing the wheel position specifying process can be increased by executing the wheel position specifying process when the communication status is good. Here, the wheel position specifying process may be executed a predetermined number of times at maximum.

  The control unit 40 determines whether the wheel position specifying process is completed (S30). If it is determined that the wheel position specifying process has been completed (Y in S30), the control unit 40 ends the process. If it is determined that the wheel position specifying process is not completed (N in S30), the control unit 40 increments the loop count i (S32). The control unit 40 determines whether or not the loop count i has reached a predetermined loop count N (S34). The control unit 40 repeats the wheel position specifying process until the loop count i reaches a predetermined loop count N (N in S34). If it is determined that the loop count i has reached the predetermined loop count N (Y in S34), the control unit 40 ends the process. By setting an upper limit to the number of repetitions of the wheel position specifying process every predetermined time, power consumption can be suppressed.

  The present invention has been described above based on the embodiment. It is to be understood by those skilled in the art that these embodiments are exemplifications, and that various modifications are possible for each component, and that such modifications are also within the scope of the present invention.

  For example, the wheel position specifying unit 34 may divide the completion flag indicating that the wheel position specifying process has been completed into a front wheel and a rear wheel, and independently generate them. That is, the wheel position specifying unit 34 generates a front wheel completion flag and a rear wheel completion flag. At this time, the wheel position specifying process may be completed according to the generation of each completion flag. Thereby, the power consumption in the wheel position specifying process can be suppressed.

  Further, if the wheel position specifying process is incomplete even if the wheel position specifying process is tried a predetermined number of loops, the control unit 40 determines that the wheel position specifying process is incomplete via the alarm device 24. May be communicated to the person.

It is a whole lineblock diagram of the wheel position specific system concerning an embodiment. It is a figure which shows the relationship between the rotation angle of a wheel, and the communication state of a transmitter / receiver and a receiver. FIG. 2A shows the relationship between the rotation angle of the wheel and the intensity when the receiver receives the radio wave transmitted from the transceiver. FIG.2 (b) shows the rotation angle of the communication failure state of a wheel. It is a figure which shows the function structure of ECU which concerns on embodiment. It is a flowchart which shows the process which pinpoints the position of each wheel which concerns on embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Vehicle, 12 Vehicle body, 14 Wheel, 16 Transmitter / receiver, 18 Transmitter, 20 Receiver, 22 Body sensor, 24 Alarm device, 26 Ignition switch, 28 Wheel sensor, 30 Wheel signal acquisition unit, 32 Wheel State detection unit, 34 wheel position specifying unit, 36 wheel identification information holding unit, 38 unreceived alarm unit, 40 control unit, 42 traveling detection unit, 44 indicating unit, 100 ECU, 200 wheel position specifying system.

Claims (5)

A wheel position specifying system for executing wheel position specifying processing,
A transmitter provided on each wheel for transmitting the wheel identification information;
A receiver that is provided in a vehicle main body to which each wheel is mounted, and that receives the identification information;
Wheel position specifying means for specifying the position of the wheel provided with the transmitter that has transmitted the identification information based on the identification information;
Control means for controlling the wheel position specifying process, and determining whether the wheel position specifying means specified the position of each wheel;
Vehicle running detection means for detecting the running of the vehicle,
When the control unit determines that the wheel position specifying unit does not specify the position of each wheel when the vehicle is stopped, the control unit performs the wheel position specifying process after the vehicle travel detecting unit detects the travel of the vehicle. A wheel location system characterized by re-execution.   The wheel position specifying system according to claim 1, wherein the control means executes the wheel position specifying process a predetermined number of times, and stops the wheel position specifying process if the position of each wheel cannot be specified. . The transmitter transmits wheel state information detected by a sensor provided on a wheel to the receiver at a predetermined period, separately from the transmission process in the wheel position specifying process,
The control means re-executes the wheel position specifying process if the receiver has received the wheel state information when the wheel position specifying means has not specified the position of each wheel. The wheel position specifying system according to claim 1 or 2.   The wheel position specifying system according to any one of claims 1 to 3, wherein the wheel position specifying means distinguishes a traveling wheel and a spare tire based on an output of an acceleration sensor provided on each wheel.   The wheel position specifying system according to claim 4, wherein the control unit does not execute the wheel position specifying process until the spare tire is specified in a vehicle including the spare tire.

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