JP2005349958A - Tire air pressure monitoring system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tire air pressure monitoring system that can accurately and simply register in a receiver IDs of transmitters on a vehicle for detecting tire air pressures with air pressure sensors and transmitting air pressure signals to the receiver. <P>SOLUTION: The tire air pressure monitoring system has the transmitters for detecting tire air pressures with the air pressure sensors and transmitting air pressure signals, and the receiver for receiving the signals from the transmitters and producing a warning signal depending on the tire air pressures. The transmitters transmit ID signals of the transmitters included in the air pressure signals. In an ID registration state to register the IDs of the transmitters (S12), if the number of received air pressure signals is a preset ID registration number α, the receiver registers the IDs of the transmitters according to the ID signals included in the received air pressure signals (S20, S26). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a tire pressure monitoring device, and more particularly to a technique for registering an ID of a transmitter that detects a tire pressure by a pressure sensor and transmits a pressure signal to a receiver.

  2. Description of the Related Art In recent years, there has been provided an apparatus having a tire pressure sensor in a tire, wirelessly transmitting air pressure information from the tire pressure sensor as a pressure signal with a transmitter installed on the tire, and receiving the pressure signal with a receiver in the vehicle. Developed and put into practical use. In this device, when the value of the air pressure signal received by the receiver is lower than a predetermined value, for example, a warning light provided near the driver's seat of the vehicle (instrument panel, etc.) is turned on. It warns that the tire pressure needs to be refilled.

By the way, the air pressure signal includes individual ID information of the transmitter (or tire pressure sensor) in addition to the air pressure information, and the individual ID information of the transmitter is received in advance at the time of shipment or wheel replacement. By registering in the machine, it is possible to determine which tire pressure has decreased.
As a method for registering the ID of the transmitter, for example, a method for forcibly transmitting an ID signal from a tire pressure sensor using a registration tool, or an ID signal is transmitted along with the air pressure signal from the tire pressure sensor periodically by running. There are a method, a method of transmitting an ID signal together with a pneumatic pressure signal from a tire pressure sensor by temporarily and rapidly changing the tire pressure.

  However, in the method in which the ID signal is transmitted from the transmitter and received by the receiver in this way, for example, when the ID signal is transmitted together with the air pressure signal from another nearby vehicle during ID registration of the own vehicle. In addition, the ID signal from the other vehicle may be erroneously registered as the ID signal of the own vehicle, which is not preferable. In places where many vehicles are gathered in one place, such as at the time of shipment or at a vehicle maintenance shop, it is easy to input ID signals of other vehicles, and this problem occurs when the ID of a transmitter is registered at such a place. Is remarkable.

For this reason, the ID signal transmission order is set in advance as the ID permutation for n tires of the host vehicle, and ID registration is performed when the order of the received ID signals does not match the preset ID permutation. An apparatus that is not configured is considered (Patent Document 1).
In addition, when a plurality of tires of the own vehicle are repeatedly transmitted with an ID signal every predetermined period and a preset time has elapsed, when the number of signals received is larger than the ID signals of n tires to be registered, An apparatus having a configuration in which n ID signals are registered as tires of the host vehicle from the higher reception frequency is considered (Patent Document 2).
JP 2002-131165 A Japanese Patent No. 3061047

However, the apparatus disclosed in Patent Document 1 has a problem that even if the number of ID signals is the same, the ID is not registered when the order of the ID signals is changed for some reason.
In the case of the device disclosed in Patent Document 2, when an ID signal is frequently transmitted from another nearby vehicle, the ID of the other vehicle may be erroneously registered. . In this case, there is a further problem that it is necessary to continuously receive the same ID signal repeatedly until a certain frequency is reached, and it takes time for ID registration.

  The present invention has been made to solve such problems, and an object of the present invention is to detect a tire pressure of a tire by a pneumatic sensor and transmit a pneumatic pressure signal to a receiver. An object of the present invention is to provide a tire pressure monitoring device capable of registering an ID accurately and easily in a receiver.

  In order to achieve the above object, in the tire pressure monitoring device according to claim 1, a transmitter attached to a tire of a vehicle, which detects a pressure of the tire by a pressure sensor and transmits a pressure signal, and a transmitter And a receiver that issues a warning signal according to the tire air pressure, the transmitter transmits an ID signal of the transmitter included in the air pressure signal, When the receiver is in an ID registration state for registering the ID of the transmitter, when the number of received air pressure signals is a predetermined value set in advance, the transmission is performed based on an ID signal included in the received air pressure signal. The machine ID is registered.

  That is, when the receiver is in the ID registration state for registering the ID of the transmitter, when the ID signal of each transmitter is transmitted together with the air pressure signal from the transmitter provided in each tire of the host vehicle, the ID signal Is received by the receiver and the ID of each transmitter is registered. At this time, the received ID signal is received only when the number of received air pressure signals, that is, the number of ID signals is a predetermined value. The ID of the transmitter is registered based on the above. That is, when the number of ID signals is larger than a predetermined value (for example, the number of tires α of the host vehicle), it is determined that the receiver may have received ID signals of other nearby vehicles. Thus, ID registration is not performed.

In the tire pressure monitoring apparatus according to claim 2, the receiver is input with information that is different from the air pressure signal and that has transmitted all of the air pressure signals of the transmitter to register the ID. Or when a predetermined time has elapsed since the start of the ID registration state, the ID registration is terminated.
Further, in the tire pressure monitoring device according to claim 3, the function of distinguishing whether the air pressure signal is a signal transmitted for ID registration or a signal transmitted as a normal air pressure signal. The receiver includes a code, and the receiver registers the ID of the transmitter when the function code is a code corresponding to a signal transmitted for ID registration.

  According to the tire pressure monitoring apparatus of the first aspect, when the receiver is in an ID registration state in which the ID of the transmitter is registered, the air pressure signal received by the receiver, that is, the number of ID signals is set to a predetermined value (for example, If the ID of the transmitter is registered in the receiver only when the number of tires of the host vehicle coincides with the number of tires α), and the number of ID signals is larger than the predetermined value, IDs from other vehicles in the vicinity Since it is judged that the signal is received and registration of the transmitter ID is not performed, the transmitter ID of the other vehicle in the vicinity is misregistered as the ID of the transmitter of the own vehicle with a simple configuration. You can avoid it. This makes it possible to register the ID of the transmitter of the host vehicle in the receiver accurately and easily even in a place where an ID signal from another nearby vehicle is easily input.

  According to the tire air pressure monitoring device of claim 2, the receiver receives the information indicating that all of the air pressure signals of the transmitter that should register the ID are input separately from the air pressure signal, or the ID registration Since registration of ID is terminated when a predetermined time has elapsed from the start of the state, the opportunity for registration of an extra ID signal other than the signal from the transmitter provided on the tire of the host vehicle to the receiver is minimized. The ID of the transmitter of the own vehicle can be registered in the receiver accurately and promptly.

  According to the tire pressure monitoring apparatus of claim 3, the receiver registers the ID of the transmitter only when the function code included in the air pressure signal is a code corresponding to the signal transmitted for ID registration. Therefore, when the function code is a signal transmitted as a normal air pressure signal, the transmitter ID can be prevented from being registered. That is, when the function code included in the air pressure signal from another nearby vehicle is simply a signal transmitted as a normal air pressure signal, registration of the ID signal included in the air pressure signal can be eliminated, The transmitter ID can be registered in the receiver more accurately.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
Referring to FIG. 1, there is shown a schematic configuration diagram of a tire pressure monitoring device according to the present invention mounted on a vehicle 1, and the configuration of the tire pressure monitoring device will be described below.
As shown in the figure, the vehicle 1 is provided with, for example, four wheels, that is, a left front wheel Wfl, a right front wheel Wfr, a left rear wheel Wrl, and a right rear wheel Wrr, and each wheel Wfl, Wfr, Wrl, Wrr. The rubber tires 20, 21, 22, and 23 are externally fitted around the rims of the steel or aluminum wheels 10, 11, 12, and 13, respectively.

The tires 20, 21, 22, and 23 are, for example, tubeless tires, and air injection valves 30, 31, 32, and 33 are provided on the rims of the wheels 10, 11, 12, and 13, respectively.
Further, transmitters 40, 41, 42, 43 equipped with air pressure sensors are attached to the valves 30, 31, 32, 33 for injecting air. The air pressure of each tire can be detected by a sensor, and an air pressure signal corresponding to the air pressure information can be transmitted wirelessly.

On the other hand, in the interior of the vehicle 1, for example, as a part of an electronic control unit (ECU) that performs various controls of the vehicle 1, a receiver 50 that receives air pressure signals from the transmitters 40, 41, 42, 43. Is arranged.
The receiver 50 is provided with a receiving circuit 52 that detects a received radio wave from the antenna 51, a CPU 53 that performs arithmetic processing based on a signal from the receiving circuit 52, and a memory 54 that stores data processed by the CPU 53. It has been. In addition, a warning lamp 55 is connected to the CPU 53 via an output interface. The warning light 55 is provided in the vicinity of the driver's seat of the vehicle 1, for example, on the instrument panel. Further, the CPU 53 is provided with a connection connector 23a of an external input / output device (Multi-Use Tester, hereinafter referred to as MUT) (not shown). Although not shown, the MUT includes an input operation button (input key) and a display capable of displaying the operation content from the MUT to the CPU 53 and the state of the CPU 53, and various adjustments of the ECU can be performed by the MUT.

  That is, in the tire pressure monitoring device, when a pneumatic pressure signal is wirelessly transmitted from the transmitters 40, 41, 42, 43 according to, for example, a decrease in the pneumatic pressure of the tires 20, 21, 22, 23, the pneumatic pressure signal is received by the receiver. When the air pressure is below the air pressure warning threshold value, the warning signal is output to the warning lamp 55.

  Specifically, the air pressure signals transmitted from the transmitters 40, 41, 42, and 43 include IDs assigned to the respective transmitters as ID signals in addition to the air pressure information. The device 50 can determine which of the transmitters 40, 41, 42, and 43 is the signal. That is, the receiver 50 can accurately identify which of the tires 20, 21, 22, and 23 is the air pressure information of the tire by the ID signal. For example, as shown in FIG. 1, ID: AAAA corresponds to the transmitter 40, ID: BBBB corresponds to the transmitter 41, ID: CCCC corresponds to the transmitter 42, and ID: DDDD corresponds to the transmitter 43. It corresponds.

  That is, when the air pressure of any of the tires 20, 21, 22, and 23 decreases, which tire air pressure decreases due to the coincidence determination between the ID signal transmitted together with the air pressure signal and the ID stored in the receiver 50 Is received by the receiver 50 and a warning signal is issued individually, and a warning that the air pressure has dropped is output to the warning lamp 55 by lighting or flashing. The warning lamp 55 is configured to be capable of warning individually for each tire 20, 21, 22, 23, for example, in accordance with a warning signal, so that the driver can easily recognize which tire is the warning. .

  By the way, in order to determine which of the transmitters 40, 41, 42, and 43 is the pneumatic signal from the receiver 50, the receiver 50 is preliminarily used at the time of shipment of the vehicle 1 or at the time of wheel replacement. It is necessary to register the ID set for each transmitter in the memory 54. Therefore, the receiver 50 is configured to be able to switch from the normal mode that warns of a decrease in air pressure to the ID registration mode for performing ID registration.

  On the other hand, when registering the ID, it is common to perform ID registration by wirelessly transmitting an ID signal from each transmitter with the receiver 50 in an ID registration mode. Thus, when performing ID registration at a place where many vehicles gather around the vehicle 1 as described above, it is easy to input an ID signal from a transmitter of another vehicle other than the ID signal of the vehicle 1. There is a possibility that the IDs of transmitters of other vehicles may be erroneously registered instead of the IDs of the transmitters of one.

In addition, it is desirable to perform the ID registration work as soon as possible when the vehicle 1 is shipped or wheels are replaced.
In the present invention, such problems are solved, and the ID registration work content of the tire pressure monitoring device according to the present invention will be described below.
In the ID registration work, the MUT is connected to the connection connector 23a, the normal mode is switched to the ID registration mode by the MUT, and the air pressure signal is transmitted from each transmitter 40, 41, 42, 43 by the forced transmission means. Each work will be sent separately to carry out the work.

Referring to FIG. 2, a control routine for ID registration control executed by the receiver 50 is shown in a flowchart, which will be described below.
In step S 10, the ID registration number α is set in the CPU 53 by operating the connected MUT. Here, the ID registration number α is, for example, a number corresponding to each wheel Wfl, Wfr, Wrl, Wrr, that is, four.

  In step S12, it is determined whether or not the receiver 50 is in the ID registration mode. Here, for example, after switching from the normal mode to the ID registration mode by the MUT, it is determined whether or not the ID registration mode is based on whether or not the display on the display of the MUT is the “ID registration mode”. If the determination result is false (No), step S12 is executed again. If the determination result is true (Yes) and the ID registration mode is determined, the process proceeds to step S14.

In step S14, as will be described in detail later, it is determined whether or not an ID registration end operation has been performed by the MUT, or whether or not a predetermined time has elapsed since switching to the ID registration mode. Immediately after switching to the ID registration mode, the determination result is false (No), and the process proceeds to step S16.
In step S16, it is determined whether or not the receiver 50 has received an air pressure signal from each transmitter 40, 41, 42, 43 according to a transmission command from the forced transmission means to each transmitter 40, 41, 42, 43. Determine. If the determination result is false (No) and it is determined that no air pressure signal has been received, the process returns to step S12. On the other hand, if the determination result is true (Yes) and it is determined that one of the pneumatic signals of the transmitters 40, 41, 42, and 43 has been received, the process proceeds to step S18.

  In step S18, it is determined whether or not the received air pressure signal includes a function code capable of ID registration. Specifically, each transmitter 40, 41, 42, 43 is configured to transmit a pneumatic signal including a function code for ID registration different from a normal function code by a forced transmission means. It is determined whether or not the receiver 50 has received an air pressure signal including an ID registration function code. If the determination result is false (No) and the function code is not an ID registration function but a normal function code, the process returns to step S12. On the other hand, if the determination result is true (Yes) and the function code is a function code for ID registration, the process proceeds to step S20.

  In step S20, the ID of the ID signal included in the air pressure signal received by the receiver 50 is stored in the memory 54 and registered. Then, in step S22, the count value N of the registered number counter of the CPU 53 is added by the number of received air pressure signals and therefore ID signals (N = N + 1). Note that the initial value of the count value N of the registration number counter is reset to 0 when the mode is switched to the ID registration mode (initial value: N = 0).

In step S24, as in step S14, it is determined whether or not an ID registration end operation has been performed by the MUT, or whether or not a predetermined time has elapsed since switching to the ID registration mode.
That is, in the ID registration work, the forcible transmission means forcibly transmits the air pressure signals individually from the transmitters 40, 41, 42, and 43, but all of the transmitters 40, 41, 42, and 43 are transmitted. When the air pressure signal is forcibly transmitted, the ID registration end operation is performed in the MUT, and thereafter, even if the air pressure signal is received, the ID is not stored in the memory 54 and the registration number counter is not incremented. Here, it is determined whether or not the ID registration end operation has been performed.

Alternatively, the time normally required for ID registration after switching to the ID registration mode is set in advance as a predetermined time (for example, 5 minutes), and it is determined whether or not the predetermined time has elapsed.
If the determination result in step S24 is false (No), the process returns to step S12. On the other hand, if the determination result is true (Yes) and there is an ID registration end operation or a predetermined time has elapsed, Even if the air pressure signal is received, the ID is not stored in the memory 54, the ID registration is terminated, the registration number counter is not added, and the process proceeds to step S26. Note that the process proceeds to step S26 in the same manner when the determination result in step S14 is true (Yes).

  In step S26, it is determined whether or not the count value N of the added registration number counter is equal to the ID registration number α (N = α). That is, the number of IDs registered based on the ID signals transmitted from the transmitters 40, 41, 42, and 43 should be the number of transmitters, that is, 4 and coincide with the ID registration number α. The receiver 50 determines whether or not all IDs corresponding to the transmitters 40, 41, 42, and 43 are registered in the memory 54.

If the determination result in step S26 is true (Yes) and it is determined that the count value N is equal to the ID registration number α (N = α), the ID corresponding to each transmitter 40, 41, 42, 43 Can be determined to be properly registered in the memory 54, and the routine is exited.
On the other hand, if the determination result in step S26 is false (No) and it is determined that the count value N does not match the ID registration number α (N ≠ α), for example, the count value N is greater than the ID registration number α (N > Α), it can be determined that an ID signal from a transmitter of another vehicle other than the ID signal of the vehicle 1 is input, and the ID of the transmitter of the other vehicle is erroneously registered. Then, the process proceeds to step S28. For example, when the count value N is smaller than the ID registration number α (N <α), a disturbance signal is included in the signals from the transmitters 40, 41, 42, and 43, and the ID is normally registered. It can be determined that there is not, and the process proceeds to step S28.

  In step S28, the ID already stored and registered in the memory 54 is temporarily deleted. Then, for example, “registration failure” is displayed on the display of the MUT, and then the routine is temporarily exited. Then, the routine is executed again. That is, when it can be determined that the receiver 50 has registered the ID by mistake, it is regarded as a registration failure, and finally the ID is not registered.

Thus, in the ID registration control according to the present invention, when the count value N of the ID registration number counter is different from the preset ID registration number α, the ID is not finally registered in the receiver 50. Yes.
Therefore, according to the tire pressure monitoring device of the present invention, the IDs individually assigned to the transmitters 40, 41, 42, and 43 can be accurately registered in the receiver 50 without erroneous registration. Furthermore, since it is only necessary to determine whether or not the count value N of the ID registration number counter matches the preset ID registration number α, ID registration can be easily implemented with a simple configuration.

Also, here, when there is an ID registration end operation by MUT, or when a predetermined time has elapsed since switching to the ID registration mode, the ID is stored in the memory 54 even if a pneumatic signal is received thereafter. The ID registration is terminated without storing, and the registration number counter is not added.
As a result, the opportunity to inadvertently register extra ID signals other than the signals from the transmitters 40, 41, 42, 43 of the vehicle 1 in the receiver 50 can be reduced as much as possible. The IDs of the machines 40, 41, 42, and 43 can be accurately registered in the receiver 50 promptly.

Further, here, ID registration is permitted only when the air pressure signal includes an ID registration function code.
Thus, when the function code is a normal function code, for example, even when a signal transmitted as a normal air pressure signal from another vehicle nearby is input to the receiver 50, the normal air pressure signal The registration of the IDs of the transmitters of other vehicles included in the vehicle can be well eliminated, and the IDs of the transmitters 40, 41, 42, 43 of the vehicle 1 can be registered in the receiver 50 more accurately.

This is the end of the description of the embodiment of the tire pressure monitoring device according to the present invention, but the embodiment is not limited to the above.
For example, in the above embodiment, the tires 20, 21, 22, and 23 are, for example, tubeless tires, and the air injection valves 30, 31, 32, and 33 provided on the rims of the wheels 10, 11, 12, and 13 are used. Although the transmitters 40, 41, 42, and 43 attached to each other have been described as examples, the tires 20, 21, 22, and 23 may be tube tires. In this case, the transmitter is attached to each tube valve. It only has to be done.

Moreover, although the said embodiment demonstrated the case where ID registration was performed about four transmitters 40, 41, 42, and 43 about the wheel Wfl, Wfr, Wrl, and Wrr, the vehicle 1 carries a spare tire in the vehicle 1 If it is, the ID should be registered for the spare tire transmitter. In this case, the ID registration number α is 5 or more depending on the number of spare tires.
Moreover, although the said embodiment demonstrated the case where ID registration was performed about all the transmitters 40, 41, 42, and 43 of the wheel Wfl, Wfr, Wrl, and Wrr, For example, among wheel Wfl, Wfr, Wrl, and Wrr When one of the wheels or tubes is replaced, the ID may be registered along the ID registration control routine only for the replaced unregistered transmitter. In this case, the ID registration number α is a number corresponding to the number of exchanged unregistered transmitters.

  In the above embodiment, as an ID registration procedure, after the ID is temporarily stored and registered in the memory 54 in step S20, the count value N of the ID registration number counter matches the preset ID registration number α in step S26. The ID registration is maintained if they match, and the IDs stored in step S28 are erased if they do not match. However, these orders are changed, and the ID registration number counter The ID may be stored in the memory 54 and registered only when the count value N matches the preset ID registration number α.

1 is a schematic configuration diagram of a tire pressure monitoring device according to the present invention mounted on a vehicle. It is a flowchart which shows the control routine of ID registration control which a receiver performs.

Explanation of symbols

1 Vehicle 10, 11, 12, 13 Wheel 20, 21, 22, 23 Tire 40, 41, 42, 43 Transmitter 50 Receiver 52 Reception circuit 53 CPU
54 Memory 55 Warning light

Claims (3)

A transmitter that is attached to a tire of a vehicle and detects the air pressure of the tire by an air pressure sensor and transmits an air pressure signal, and a receiver that receives a signal from the transmitter and issues a warning signal according to the air pressure of the tire A tire pressure monitoring device having:
The transmitter transmits the ID signal of the transmitter included in the air pressure signal,
The receiver is in an ID registration state for registering the ID of the transmitter, and when the number of received air pressure signals is a predetermined value set in advance, the receiver is based on the ID signal included in the received air pressure signal. A tire pressure monitoring device, wherein an ID of a transmitter is registered.   The receiver is information different from the air pressure signal, and is input when information indicating that all of the air pressure signals of the transmitter to which ID is to be transmitted is input or from the start of the ID registration state. The tire pressure monitoring apparatus according to claim 1, wherein the registration of the ID is terminated when time elapses. The air pressure signal includes a function code for distinguishing whether the air pressure signal is a signal transmitted for ID registration or a signal transmitted as a normal air pressure signal.
The tire pressure monitoring device according to claim 1 or 2, wherein the receiver registers the ID of the transmitter when the function code is a code corresponding to a signal transmitted for ID registration. .