JP2007216910A - Status monitoring device for wheel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a status monitoring device for a wheel in which discrimination information corresponding to the respective wheels is easily and accurately registered without use of a specific registration equipment and intentional registration work. <P>SOLUTION: The status monitoring device for the wheel for receiving a radio signal including measurement information WI radio-transmitted from the respective wheels 40 and the discrimination information ID by a receiving antenna 20, and for individually determining the status of the respective wheels 40 in an information processing part 1 based on the measurement information WI and the discrimination information ID demodulated in the receiving part 30, is provided with a following constitution. The information processing part 1 has: a memory means 2 for storing intensity information RI indicating electric wave intensity of the radio signal corresponding to the respective receiving antennas 20 and the discrimination information ID; an integration means 3 for integrating the intensity information RI for every receiving antenna 20 and discrimination information ID; and a determination means 4 for determining the discrimination information ID corresponding to the respective wheels 40 positioned near the respective receiving antennas 20, based on the integrated intensity information RI. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a wheel state monitoring device that individually determines the state of each wheel of a vehicle based on measurement information of each wheel wirelessly transmitted together with identification information.

2. Description of the Related Art A wheel state monitoring device that includes a sensor such as an air pressure sensor or a temperature sensor and a wireless transmission unit in a tire wheel or the like and determines the state of the wheel based on wirelessly transmitted information is known. Japanese Patent Application Publication No. JP-A-2001-259542, which is cited below, describes a tire pressure monitoring system in which all wireless transmission means have a unique and unique identification code in order to verify the source of transmission data. Since the information obtained by the sensor is transmitted together with the identification code, it is possible to determine the state of the wheel after specifying which wheel is the information.
For this purpose, it is necessary to associate the identification code with the wheel position in advance. However, there may be a case where the relationship between the identification code and the wheel position associated in advance by the rotation of the tire by the user or the replacement of the tire moves.

The tire pressure system described in Patent Document 1 is configured so that the identification code can be easily reset for each wheel in such a case. According to this, first, the operator turns on the registration switch on the receiver side to place the receiver in the registration mode of the identification code. The receiver clearly indicates the position of the wheel to be registered with the identification code by voice or display, and enters a reception waiting state.
Next, the operator pushes the shaft portion of the air valve of the wheel at the target position to reduce the air pressure. Due to this pressure change, the identification code is wirelessly transmitted together with the air pressure information from the transmitter provided on the target wheel. The receiver in the registration mode receives this as transmission information from the target wheel and primarily stores the identification information. Then, the position of the next wheel is clearly indicated, and a reception waiting state is entered.
Thereafter, the same operation as described above is performed for all the wheels. When the identification codes for all the wheels are temporarily stored, the receiver clearly indicates that all the reception has been completed, and stores the correspondence between the wheels and the identification information in a non-volatile storage medium (for example, EEPROM or flash memory). To do.

Japanese Patent No. 3401535 (9th to 15th paragraphs)

  The registration method of the identification code described in Patent Document 1 is excellent in that a special registration device is not used and the possibility of erroneous registration is low. However, the operator needs to put the receiver into the registration mode, which can generally be performed only by a store or a repair shop. Therefore, it is impossible to cope with a case where a user of a car performs tire rotation or tire replacement. Even if the registration mode setting is open to the user, the user may forget to register.

  The present application has been made in view of the above-described problems. An operator and a user can easily and accurately identify each wheel without using a special registration device or conscious registration work. An object of the present invention is to provide a wheel state monitoring device capable of registering information.

In order to achieve the above object, a wheel state monitoring apparatus according to the present invention is configured as follows.
Each wheel of the vehicle is provided with each of the wheels of the vehicle, measures at least the air pressure of the wheel, modulates measurement information including the air pressure together with identification information and wirelessly transmits the signal, and receives each wireless signal from the transmitter. A receiving antenna provided at a position corresponding to each of the above, a receiving unit that demodulates the radio signal, and a state of each wheel of the vehicle based on the measurement information and the identification information obtained through the receiving unit, A wheel state monitoring device including an information processing unit to be separately determined, and includes the following characteristic configuration.
The receiving unit determines the radio field intensity of the radio signal and transmits intensity information together with the measurement information and the identification information to the information processing unit,
The information processing unit includes storage means for storing the intensity information in association with each receiving antenna and the identification information;
Accumulating means for integrating the intensity information of the radio signal received a plurality of times for each receiving antenna and the identification information;
And determining means for determining the identification information corresponding to each wheel located in the vicinity of each receiving antenna based on the accumulated intensity information.

According to this feature configuration, since the identification information corresponding to each wheel is determined after integrating the intensity information over a plurality of times, accurate determination is possible. Also, since the identification information is discriminated in the same signal form as normal transmission and reception, the identification information corresponding to each wheel can be easily obtained without using a special registration device or performing conscious registration work. You can register.
In this configuration, since the receiving antenna is provided in the vicinity of each wheel, the strength of the radio signal from the transmitting unit provided in the target wheel is usually high. However, when there is another vehicle in the vicinity, or when it is affected by external noise, the strength of other radio signals may be exceeded. According to this configuration, since the intensity information of the radio signal is integrated over a plurality of transmissions / receptions, accurate determination can be performed without being influenced by other radio signals.

  The wheel state monitoring apparatus according to the present invention further includes speed detection means for detecting a vehicle speed of the vehicle, and the information processing unit receives the identification information received after the vehicle has reached a predetermined speed, and the The discriminating means is discriminated based on the intensity information.

In general, since the transmission unit provided in the wheel is battery-driven, the battery consumption is suppressed by performing transmission as necessary. Therefore, for example, when the vehicle is stopped, the need for measurement information is low, so the transmission frequency is reduced. When the transmission frequency is low, it takes a long time to determine the identification information, and it is easily affected by other radio signals between transmissions. According to this characteristic configuration, the determination is performed based on the identification information and the strength information received after the vehicle has reached a predetermined speed. Therefore, in addition to shortening the time for discriminating the identification information, it is possible to suppress the influence of a radio signal that has a fixed influence, such as an adjacent stationary vehicle.
As a result, it is possible to provide a wheel state monitoring device capable of accurately registering identification information corresponding to each wheel.

  The wheel state monitoring apparatus according to the present invention is characterized in that the receiving unit calculates an average radio wave intensity at the time of each wireless transmission and uses the intensity information as the intensity information.

When intensity information is obtained from a radio signal, for example, intensity at a predetermined point at the start of transmission / reception or after a predetermined time from the start can be used as intensity information. However, the intensity of the radio wave is easily affected by the surrounding environment, and there are cases where external noise is superimposed at the predetermined point. In such a case, the reliability of the strength information decreases. In the state monitoring apparatus of the present invention, this problem is addressed to some extent by determining after accumulating intensity information over a plurality of times of transmission and reception.
However, if the average radio wave intensity at the time of each wireless transmission is calculated as intensity information as in this feature configuration, the reliability can be further improved. As a result, it is possible to provide a wheel state monitoring device capable of accurately registering identification information corresponding to each wheel.

  In the wheel state monitoring apparatus according to the present invention, the intensity stored in the storage unit after the determination unit receives the same identification information received by at least one reception antenna a predetermined number of times. The discrimination is based on information.

  Vehicles equipped with a wheel state monitoring device are equipped with two or more wheels, usually four or more wheels. Therefore, in the configuration of the present invention, at least two receiving antennas are provided, each receiving a radio signal having identification information. In the present invention, the identification information corresponding to each wheel is determined by integrating the intensity information obtained from the transmission and reception over a plurality of times. In this feature configuration, the number of times of transmission and reception is defined by the number of times at least one receiving antenna receives the same identification information (predetermined specified number of times). That is, after at least one of the integrated intensity information is integrated for a predetermined number of times, the identification information corresponding to each wheel is determined based on all of the integrated intensity information. The

As described above, the intensity of radio waves is easily affected by the surrounding environment, and there are cases where external noise is superimposed. Furthermore, since the transmitter provided in each wheel operates independently, it does not necessarily receive the same number of times from all the wheels within the same period. Therefore, the number of receptions of certain identification information does not necessarily reach the specified number in all reception antennas at the same time.
However, even if there is some difference, if at least one of the accumulated intensity information is accumulated for a predetermined specified number of times, it can be sufficiently discriminated. In other words, since the discrimination from the integration result of the intensity information is performed for each receiving antenna, even if there is a slight difference in the number of times of reception of identification information (the number of integration) received most frequently in each receiving antenna, it is distinguished for each antenna. There is no problem if possible.
Therefore, after at least one of the accumulated intensity information is accumulated for a predetermined specified number of times, the identification information corresponding to each wheel is determined based on all the accumulated intensity information. If so, accurate discrimination can be realized.

Moreover, the wheel state monitoring apparatus according to the present invention corresponds to each wheel located in the vicinity of each receiving antenna when the determination unit matches a first determination result and a second determination result shown below. The identification information is determined.
The first determination result is based on all of the accumulated intensity information after at least one of the accumulated intensity information is accumulated for a predetermined first specified number of times. It is determined by.
The second determination result is obtained after the at least one of the intensity information accumulated after the determination of the first determination result is integrated for a predetermined second specified number of times. Is determined by the determination means based on all of the intensity information accumulated after the determination.

  According to this characteristic configuration, it is confirmed that the relationship between each wheel and the identification information determined based on the intensity information accumulated over a plurality of times of transmission / reception is the same twice continuously. . Therefore, more accurate discrimination is possible.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a block diagram schematically showing the configuration of the wheel state monitoring apparatus of the present invention. In this example, a wheel state monitoring device mounted on a vehicle having four wheels 40 (41 to 44) will be described as an example.
As shown in the figure, the wheel state monitoring device receives the wireless signals from the transmission units 10 (11 to 14) provided in the wheels 40, respectively, and at positions corresponding to the wheels of the vehicle. It has the receiving antenna 20 (21-24) provided, the receiving part 30 (31-34) which demodulates a radio signal, and the information processing part 1 which determines the state of each wheel 40 separately. Each receiving unit 30 and the information processing unit 1 are connected by a wired wiring 7.

The transmission unit 10 wirelessly transmits measurement information WI detected by a sensor such as a pneumatic sensor or a temperature sensor (not shown) together with an identification information ID that identifies each wheel. Although not shown, the transmission unit 10 is provided with a transmission antenna inside a wheel, for example, in a tire.
In this example, a weak radio wave is used as the radio wave transmitted by the transmission unit 10, and the reception antenna 20 is disposed in the vicinity of each wheel 40. The receiving unit 30 demodulates the measurement information WI and the identification information ID from the radio signal received by the receiving antenna 20. In FIG. 1, the antenna is disposed in the vicinity of the wheel 40 together with the receiving antenna 20, but the present invention is not limited to this, and any location on the wiring 7 or the information processing unit 1 may be disposed.
The receiving unit 30 also determines the radio field intensity of the radio signal received by the receiving antenna 20 and converts it into quantitative information as intensity information RI. Accordingly, the intensity information RI is transmitted from the receiving unit 30 to the information processing unit 1 together with the demodulated measurement information WI and identification information ID.

FIG. 2 is a block diagram schematically illustrating a configuration example of the information processing unit 1 in FIG. The information processing unit 1 includes a storage unit 2, an integration unit 3, a determination unit 4, and a state determination unit 5.
The storage unit 2 stores the intensity information RI in association with each receiving antenna 20 and the identification information ID. The accumulating means 3 accumulates the intensity information RI of the radio signal received a plurality of times for each receiving antenna 20 and identification information ID. In the configuration example shown in FIG. 2, the integrating unit 3 adds the intensity information RI stored in the storage unit 2 and the newly received intensity information RI to update the intensity information RI to the integrated information. The discriminating means 4 discriminates the identification information ID corresponding to each wheel 40 located in the vicinity of each receiving antenna 20 based on the integrated intensity information RI. Details of the storage unit 2, integration unit 3, and determination unit 4 will be described later with reference to the flowcharts shown in FIGS.
The state determination means 5 determines the state of the wheel 40 based on the identification information ID and the measurement information WI when the position of each wheel 40 is specified, and based on the measurement information WI when the position is not specified. To do.

As shown in FIG. 2, speed information is transmitted to the information processing unit 1 from speed detection means 9 that detects the speed of the vehicle. The speed detection means 9 detects the speed of the vehicle using, for example, a rotation detection sensor provided in the vicinity of the wheel 40. The information processing unit 1 determines the identification information corresponding to each wheel based on the identification information ID and the intensity information RI received after the vehicle reaches a predetermined speed.
In general, the transmission unit 10 provided in the wheel 40 is battery-driven, so that battery consumption is suppressed by performing transmission as necessary. Therefore, for example, when the vehicle is stopped, since the necessity of the measurement information WI is low, the transmission frequency is reduced. When the transmission frequency is low, it takes a long time to determine the identification information ID, and it is easily affected by other radio signals between transmissions. Therefore, based on the information from the speed detection means 9, the determination is performed based on the identification information ID and the intensity information RI received after the vehicle has reached a predetermined speed.
Further, the information processing unit 1 outputs the state monitoring result of the wheel 40 to the indicator 8. The indicator 8 displays measurement information WI for each wheel 40.

Hereinafter, a method for determining the identification information ID corresponding to each wheel 40 will be specifically described. FIG. 3 is a waveform diagram schematically showing a radio signal received by each receiving antenna 20. The waveform of the radio signal R1 received by the receiving antenna 21 from the upper stage, the waveform of the radio signal R2 received by the receiving antenna 22, the waveform of the radio signal R3 received by the receiving antenna 23, and the waveform of the radio signal R4 received by the receiving antenna 24 Show.
The portion protruding in the amplitude direction (time T) is a portion where a radio signal transmitted by any of the transmission units 10 or a radio signal similar to the radio signal transmitted by the transmission unit 10 exists. That is, the period of time T is one wireless transmission / reception period.
The values of the identification information ID obtained when demodulating the radio signal in one transmission / reception period T are indicated by S1 to S5. The identification information values S1, S2, S3, and S4 are identification information values corresponding to the wheels 41, 42, 43, and 44, respectively, and the identification information value S5 is an identification information value that is unrelated to any of the wheels 40 of the vehicle. .

The radio signal received in one transmission / reception period T is not limited to demodulating the measurement information WI and the identification information ID, but the radio field intensity is determined and converted into quantitative information as the intensity information RI. The intensity information RI may be obtained, for example, by converting the intensity at a predetermined point at the start of transmission / reception or a predetermined time after the start to quantitative information as it is. However, the intensity of the radio wave is easily influenced by the surrounding environment, and there are cases where external noise is superimposed at the predetermined point.
For example, in the radio signal R1 received by the receiving antenna 21, it is desirable that the radio signal having the identification signal value S1 of the wheel 41 is quantified as having the highest radio wave intensity. However, as shown in the upper right side of FIG. 3, at the start of the transmission / reception period T, the radio field intensity L2 of the radio signal having the identification signal value S3 is stronger than the radio field intensity L1 of the radio signal having the identification signal value S1. Indicates strength. In such a case, the reliability of the intensity information RI decreases.

  In order to suppress this problem, in the present invention, the radio field intensity (intensity) integrated over a plurality of transmissions / receptions without determining the relationship between the identification information ID and the wheel 40 based on the radio field intensity RI in one transmission / reception. It is determined based on information RI). Here, if the average radio wave intensity in the transmission / reception period T is calculated to obtain the intensity information RI, the reliability can be further improved.

  The intensity information RI is quantified by evaluating the amplitudes of the radio signals R1 to R4 shown in FIG. In the figure, Ith indicates the lowest receivable radio wave intensity, and with this as zero, intensity information RI quantified in 10 levels 1 to 10 is transmitted to the information processing unit 1.

FIG. 4 is a flowchart illustrating a procedure for determining the identification information ID of each wheel 40, and FIG. 6 is an explanatory diagram schematically illustrating a storage method and an accumulation method of the intensity information RI.
It is sufficient to determine the position of the wheel 40, that is, to determine the identification information ID corresponding to each wheel 40 once in the “initial stage” such as after tire mounting, after rotation, after replacement, or the like. Therefore, when it has a recognition means for recognizing the attachment of a tire, it may be performed based on an instruction from this recognition means. In addition, if such a recognition means is not provided, it may be performed once in the “initial stage” such as after the ignition key is turned on, after the engine is started, and after the stop state is changed to the running state. It is enough.
Hereinafter, in this example, a case will be described in which position determination is performed once in a state where the ignition key is turned on.

Reference is first made to FIG. The information processing section 1 determines whether or not the ignition key is on (# 11), and if it is on, determines whether or not a signal is input from the receiving section 30 (# 12). In the processes # 11 and # 12, when the determination is negative, the same process is executed again. If a signal is input from the receiving unit 30, the input from the speed detecting means 9 is confirmed (# 13), and if the vehicle speed is above a certain level, the strength information RI and the identification information ID are received ( # 14, # 15). Then, both are associated and registered in the first table (storage means 2) (# 16). It is determined whether or not the same identification information ID received by at least one receiving antenna 20 has been received a predetermined specified number of times (first specified number of times) (# 17), and processes # 12 to 17 are performed until the specified number of times is reached. repeat.
In this iterative process, the intensity information RI stored in the first table and the newly received intensity information RI are added by the integrating means 3, and the intensity information RI updated to the integrated information is added to the first table. Written back. That is, so-called read modify write is performed.

Here, with reference to FIG. 6, the first table corresponding to the storage unit 2 and the integration unit 3 will be described.
The intensity information RI (intensity information value) and identification information ID (identification information value) of the transmission / reception period T of the radio signals R1 to R4 shown in FIG. 3 are registered in the first table shown in FIG. The information in the first half (left side) of the waveform diagram in FIG. 3 is registered in the upper left table of FIG. 6, and the information in the second half (right side) of the waveform diagram in FIG.

In the upper left table of FIG. 6, for example, identification information values S1, S2, and S3 demodulated from the radio signal R1 are registered in association with the intensity information values 9, 4, and 6, respectively. Since the identification information value S4 is not demodulated from the radio signal R1, the intensity information value is not registered (or zero is registered).
Similarly, the radio signals R2, R3, and R4 are registered in association with identification information ID (identification information value) and intensity information RI (intensity information value).

In the table on the right side of FIG. 6, for example, identification information values S1, S2, S3 demodulated from the radio signal R1 and identification information value S5 considered to be an external radio wave from another vehicle are shown as intensity information values 7, 3, 8 and 10 are registered in association with each other. Similar to the upper left table, since the identification information value S4 is not demodulated from the radio signal R1, the intensity information value is not registered.
Similarly, the radio signals R2, R3, and R4 are registered in association with identification information ID (identification information value) and intensity information RI (intensity information value). Regarding the radio signals R2, R3, and R4, the identification information value S5 that is considered to be an external radio wave is not registered because the radio wave intensity is insufficient.

  Each time the processes # 12 to 17 shown in FIG. 4 are repeated once, one table can be formed. When a new table is formed, the intensity information RI is sequentially accumulated until the specified number of times is reached by integrating with the values of the previous table. The lower table of FIG. 6 shows the first table after being repeated a prescribed number of times (for example, 10 times). S6 and S7 are observed in addition to the identification information value S5 that is considered to be an external radio wave as described above, but it is sporadic within the specified number of times (10 times), and the accumulated intensity information value can be ignored. Small enough. For example, the identification information value S5 alone has the maximum intensity information value 10 but remains 10 even if accumulated. However, the accumulated intensity information value of the correct identification information value S1 is 96, and as a result of the accumulation, the influence of the identification information value S5 is about 1/10.

  The cumulative value of the identification information values S1, S2, S3, and S4 in the radio signals R1, R2, R3, and R4 corresponding to the receiving antennas 21, 22, 23, and 24 exceeds 90 and indicates the maximum value. Thus, by integrating the intensity information RI (intensity information value), it is possible to accurately associate the wheel 40 with the identification information ID.

  Reference is again made to FIG. When it is confirmed in process # 17 that the same identification information ID received by at least one receiving antenna 20 has been received a predetermined specified number of times (first specified number), the position of the wheel 40 is determined (# 31). ). That is, the information processing unit 1 determines the identification information ID for each wheel 40 based on the intensity information RI (accumulated intensity information value) stored in the first table (storage unit 2). In other words, the discriminating means 4 is integrated after at least one of the integrated intensity information RI (intensity information value) is integrated for a predetermined specified number of times (first specified number of times). The identification information ID for each wheel 40 is determined based on all of the intensity information RI (intensity information value).

  When the position of each wheel 40 is determined, thereafter, the information processing unit 1 determines the state of the wheel 40 based on the measurement information WI and the identification information ID. Then, the indicator 8 is controlled such that the state monitoring result is output to the indicator 8 (# 32). The indicator 8 displays the measurement information WI for each wheel 40, for example. Thereafter, until it is confirmed that the ignition key is turned off (# 33), the signal input from the receiving unit 30 is confirmed at appropriate times (# 34), and the state monitoring of the wheel 40 (# 32) is continued.

  When the vehicle speed does not reach the predetermined speed in the above-described process # 13, the identification information ID determination process is not performed, and the state of the wheel 40 is monitored without using the identification information ID (# 18). ). That is, control such as displaying the state of any one wheel 40 on the indicator 8 without specifying the position of the wheel 40 is performed.

[Second Embodiment]
A second embodiment of the present invention will be described below with reference to FIGS. 5 and 7 in addition to FIGS. Note that, as appropriate, the description of the same parts as those of the first embodiment described above will be omitted.
FIG. 7 is a block diagram schematically illustrating a second embodiment of the configuration example of the information processing unit in FIG. 1. The first embodiment is different from the first embodiment in that the storage unit 2 includes a first storage unit 2a and a second storage unit 2b. About another structure, it is the same as that of 1st embodiment.
Further, the processes related to the processes # 11 to # 17 and # 18 in the flowchart shown in FIG. 4 are the same as those in the first embodiment. However, the first table corresponds to the first storage means 2a. Further, the processing after confirming that the same identification information ID received by at least one receiving antenna 20 is received a predetermined specified number of times (first specified number of times) in the process # 17 is different. That is, after the process # 17, the process shifts to the process # 31 in the first embodiment, but the second embodiment is different in that the process shifts to the process # 21 shown in FIG.

  As shown in FIG. 5, processes # 21 to # 24, which are the same processes as the processes # 12, 14, 15, and 16 described above, are executed following the process # 17. That is, the information processing unit 1 confirms the input of the signal from the receiving unit 30 and registers the intensity information RI and the identification information ID in association with each other. However, in this case, it is registered not in the first table (first storage means 2a) but in the second table (second storage means 2b) (# 24). Thereafter, similarly to the above-described process # 17, until it is confirmed that the same identification information ID received by at least one receiving antenna 20 has been received a predetermined specified number of times (second specified number of times) (# 25). The processes # 21 to 25 are repeated. The second specified number of times includes the same number as the first specified number of times, but may be a different number.

If the condition of process # 25 is satisfied, it is determined whether or not the wheel position determination result based on the first table (first determination result) matches the wheel position determination result based on the second table (second determination result). (# 26). Here, if the tire position determination results determined based on both tables match, the position of each wheel 40 (that is, the corresponding identification information ID) is determined based on the determination result (# 31). The subsequent steps are the same as those in the first embodiment already described.
If they do not match, the information processing section 1 discards the registered contents of the first table and moves the registered contents of the second table to the first table. Then, the process returns to the process # 21, and the second table registration work is performed again (# 27). This may be realized by exchanging label names and addresses between the first table and the second table.

As described above, in the second embodiment, the discriminating unit 4 determines whether the discriminating information corresponding to each wheel located in the vicinity of each receiving antenna when the first discrimination result matches the second discrimination result. To decide.
The first determination result is a result of executing the processes # 11 to # 17 and # 18 shown in FIG. In other words, after at least one of the integrated intensity information RI (intensity information value) is integrated for a predetermined first specified number of times, the integrated intensity information RI (intensity information value) It is determined by the determining means 4 based on all.
The second determination result is a result of executing the processes # 21 to # 25 and # 28 shown in FIG. In other words, after at least one of the intensity information RI (intensity information value) integrated after the determination of the first determination result is integrated for a predetermined second specified number of times, the first determination result Is determined by the determining means 4 based on all of the intensity information RI (intensity information value) accumulated after the determination.

  As described above, according to the second embodiment, the relationship between each wheel 40 and the identification information ID determined based on the intensity information RI accumulated over a plurality of times of transmission / reception is further continuously twice. Make sure they are the same. Therefore, more accurate discrimination is possible compared to the first embodiment. In addition, when the two determination results do not coincide with each other, the re-evaluation for one time is performed without re-evaluating the second time again, while maintaining the latest result at that time. Therefore, an accurate discrimination result can be obtained quickly.

  As described above, according to the present invention, an operator and a user can register identification information corresponding to each wheel easily and accurately without using special registration equipment or conscious registration work. It is possible to provide a wheel state monitoring device capable of performing the above.

The block diagram which shows typically the structure of the state monitoring apparatus of the wheel of this invention 1 is a block diagram schematically showing a configuration example of an information processing unit in FIG. Waveform diagram schematically showing radio signals received by each receiving antenna Flow chart showing the procedure for determining the identification information of each wheel The flowchart which shows another procedure which discriminate | determines the identification information of each wheel. Explanatory drawing which shows typically the storage method and integration method of intensity information FIG. 1 is a block diagram schematically showing another configuration example of the information processing unit in FIG.

Explanation of symbols

1: Information processing unit 2: Storage unit 3: Integration unit 4: Discriminating unit 9: Speed detection unit 10, 11-14: Transmission unit 20, 21-24: Reception antenna 30, 31-34: Reception unit 40, 41- 44: Wheel WI: Measurement information ID: Identification information RI: Strength information T: Time, transmission / reception period

Claims (5)

Each wheel of the vehicle is provided with each of the wheels of the vehicle, measures at least the air pressure of the wheel, modulates measurement information including the air pressure together with identification information and wirelessly transmits the signal, and receives each wireless signal from the transmitter. A receiving antenna provided at a position corresponding to each of the above, a receiving unit that demodulates the radio signal, and a state of each wheel of the vehicle based on the measurement information and the identification information obtained through the receiving unit, A state monitoring device for a wheel including an information processing unit to be separately determined,
The receiving unit determines the radio field intensity of the radio signal and transmits intensity information together with the measurement information and the identification information to the information processing unit,
The information processing unit includes storage means for storing the intensity information in association with each receiving antenna and the identification information;
Accumulating means for integrating the intensity information of the radio signal received a plurality of times for each receiving antenna and the identification information;
A wheel state monitoring device comprising: a discriminating unit that discriminates the identification information corresponding to each wheel located in the vicinity of each receiving antenna based on the integrated intensity information.   And a speed detection unit configured to detect a vehicle speed of the vehicle, wherein the information processing unit determines the determination unit based on the identification information and the strength information received after the vehicle reaches a predetermined speed. The wheel state monitoring device according to claim 1.   The wheel state monitoring device according to claim 1, wherein the receiving unit calculates an average radio wave intensity at each radio transmission and uses the intensity information as the intensity information.   The determination means determines based on all of the integrated intensity information after at least one of the integrated intensity information has been integrated a predetermined number of times. The wheel state monitoring device according to any one of the above. The discriminating means is configured to discriminate based on all of the accumulated intensity information after at least one of the accumulated intensity information is accumulated for a predetermined first specified number of times. With the results
At least one of the intensity information integrated after the determination of the first determination result is integrated after the determination of the first determination result after being accumulated for a predetermined second specified number of times. The identification information corresponding to each wheel located in the vicinity of each receiving antenna is determined when the second determination result determined based on all of the intensity information matches. The state monitoring device for a wheel according to one item.

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