JP4381236B2 - Tire pressure monitoring device - Google Patents

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 configured to provide a tire pressure sensor in a tire, wirelessly transmit air pressure information from the tire pressure sensor as a pressure signal with a transmitter installed on the tire, and receive the pressure signal with a receiver in the vehicle. Developed and put into practical use. In this apparatus, 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 methods.

  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).

A method of transmitting an ID signal together with an air pressure signal from a tire air pressure sensor by temporarily changing the tire air pressure temporarily is also considered.
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.

Further, in the method of transmitting the ID signal together with the air pressure signal from the tire air pressure sensor by changing the tire air pressure rapidly and abruptly, when the ID signal is issued from another vehicle traveling in the vicinity, the registration is also erroneously registered. The possibility remains.
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 when the tire air pressure is less than or equal to a predetermined value, the transmitter includes an ID signal of the transmitter included in the air pressure signal. And when the receiver is in an ID registration state for registering the ID of the transmitter, the tire pressure corresponding to the received air pressure signal is included in the received air pressure signal if it is equal to or less than the predetermined value. registers the ID of the transmitter based on the ID signal, the air pressure of the tire is less than the predetermined value, ID registered to the receiver the ID of the transmitter If the tire pressures coincide with each other, it is determined that the air pressure of the tire to which the transmitter having the ID is attached has decreased, and a warning signal is issued, and when the tire air pressure exceeds the predetermined value, the warning signal is canceled. Features .

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, for example, the pressure of the tire to which the transmitter for which ID registration is to be performed is lowered is set so that the tire pressure is predetermined. The ID is registered only when the value is less than or equal to the value, and the registration is not allowed for the ID input from the air pressure signal that is not less than the predetermined value.
When the tire air pressure falls below a predetermined value, if the ID of the transmitter matches the ID registered in the receiver, it is determined that the air pressure of the tire attached to the transmitter having the ID has decreased. Since the warning signal is issued, the ID is registered and the warning signal is issued when the tire air pressure falls below a predetermined value in the ID registration state. Thereafter, when the air pressure of the tire to which the transmitter that has registered the ID is attached is increased so as to return to the original pressure, the warning signal is canceled when the air pressure of the tire becomes greater than a predetermined value.

Further, in the tire pressure monitoring apparatus according to claim 2, the function 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 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.

  That is, the receiver registers the transmitter ID only when the function code included in the air pressure signal is a code corresponding to the signal transmitted for ID registration, and the function code is transmitted as a normal air pressure signal. If it is a signal, the transmitter ID is not registered.

  According to the tire pressure monitoring device of claim 1, when the receiver is in the ID registration state for registering the ID of the transmitter, for example, the pressure of the tire attached to the transmitter to which ID registration is to be performed is reduced, The ID is registered only when the air pressure of the tire falls below a predetermined value, and no registration is allowed for ID input from an air pressure signal that is not lower than the predetermined value. Thus, the ID of the transmitter of another vehicle in the vicinity can be prevented from being erroneously registered as the ID of the transmitter of the own vehicle. 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.

Further, when the receiving apparatus is in the ID registration state, a warning signal is generated with air pressure of the tire ID becomes below a predetermined value is registered, then mounted the transmitter performing the registration of the ID When the tire air pressure is increased to return to the original value, the warning signal is successfully released when the tire air pressure exceeds a predetermined value, and the ID to be registered is properly registered when the warning signal is released. Can be confirmed. On the other hand, if the warning signal is not canceled even if the tire air pressure exceeds a predetermined value, it can be easily determined that the ID is erroneously registered.

According to the tire pressure monitoring apparatus of claim 2 , the receiver registers the transmitter ID 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. In other words, 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 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.
Specifically, in the present invention, when the receiver 50 is in the ID registration mode, the air pressure of the tires 20, 21, 22, and 23 is greatly decreased sequentially or simultaneously, and the air pressure of each tire can be registered. ID registration is permitted only in the following cases.

In the ID registration work, the MUT is connected to the connection connector 23a, and the normal mode is switched to the ID registration mode by the MUT.
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, the air pressure of the tires 20, 21, 22, and 23 is greatly decreased sequentially or simultaneously, so that the air pressure of any of the tires 20, 21, 22, and 23 is decreased, and the receiver 50 transmits each transmitter 40. , 41, 42, and 43, it is determined whether or not air pressure signals have been received. 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 S16.

  In step S16, it is determined whether or not the received air pressure signal includes a function code capable of ID registration. Specifically, when the air pressure of the tires 20, 21, 22, and 23 is greatly reduced, each transmitter 40, 41, 42, and 43 transmits a pneumatic signal including a function code that can be registered with an ID different from a normal function code. Here, it is determined whether or not the receiver 50 has received an air pressure signal including a function code capable of registering the ID. 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 S18.

  In step S18, it is determined whether or not the air pressure corresponding to the received air pressure signal is equal to or less than a pre-registerable air pressure threshold value (predetermined value). Here, the registerable air pressure threshold is the same (predetermined value) as the air pressure warning threshold, but the registerable air pressure threshold may be smaller than the air pressure warning threshold (air pressure warning threshold ≧ registerable air pressure threshold). ). If the determination result is false (No) and it is determined that the air pressure is greater than the registerable air pressure threshold, the process returns to step S12. On the other hand, if the determination result is true (Yes) and it is determined that the air pressure is equal to or lower than the registerable air pressure threshold, 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.
That is, here, only when the receiver 50 is in the ID registration mode and the air pressure according to the received air pressure signal is equal to or lower than the registerable air pressure threshold, the ID of the ID signal included in the received air pressure signal is set. sign up.

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 the 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, 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, it is determined whether or not the receiver 50 has registered all the IDs to be registered corresponding to the transmitters 40, 41, 42, and 43 in the memory 54.

If the determination result in step S24 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, the routine is exited, and the ID registration operation is terminated.
On the other hand, if the determination result in step S24 is false (No) and it is determined that the count value N does not match the ID registration number α (N ≠ α), specifically, the count value N is greater than the ID registration number α. If the number is small (N <α), it can be determined that all the IDs to be registered have not yet been registered in the memory 54, and the process returns to step S12.

Thus, in the ID registration control according to the present invention, the ID is registered only when the receiver 50 is in the ID registration mode and the air pressure corresponding to the received air pressure signal is equal to or lower than the registerable air pressure threshold. Like that.
Therefore, according to the tire pressure monitoring device of the present invention, even if the ID signal is input to the receiver 50 from another nearby vehicle, the ID of the transmitter of the other vehicle is registered. The IDs individually assigned to the transmitters 40, 41, 42, and 43 can be accurately registered in the receiver 50.

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 the other vehicles included in the vehicle 1 can be eliminated more satisfactorily, and the IDs of the transmitters 40, 41, 42, 43 of the vehicle 1 can be registered in the receiver 50 more accurately.

By the way, in the tire pressure monitoring apparatus, even when the receiver 50 is in the ID registration mode, a warning signal is issued in the receiver 50 and a warning that the air pressure has decreased is output to the warning lamp 55. The air pressure warning control will also be described below.
Referring to FIG. 3, a control routine for air pressure warning control is shown, and will be described along the same flowchart.

  In step S30, as in step S14, the air pressure of any of the tires 20, 21, 22, 23 decreases, and the receiver 50 receives air pressure signals from the transmitters 40, 41, 42, 43. Is determined. 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 any of the pneumatic signals of the transmitters 40, 41, 42, and 43 has been received, the process proceeds to step S32.

As described above, in the ID registration mode, when the air pressure of the tires 20, 21, 22, 23 is greatly decreased sequentially or simultaneously, and it is determined that the air pressure signal is received by the determination in step S14 of the ID registration control, Since the determination result is naturally true (Yes), the process proceeds to step S32.
In step S <b> 32, it is determined whether or not the ID signal included in the received air pressure signal matches the ID registered in the receiver 50. If the determination result is false (No) and the IDs do not match, the routine is exited. On the other hand, if the determination result is true (Yes), the process proceeds to step S34.

As described above, when the ID is registered in step S20 of the ID registration control, the ID signal included in the air pressure signal should match the ID registered in the receiver 50, and the determination result is naturally true. Since (Yes), the process proceeds to step S34.
In step S34, it is determined whether or not the air pressure corresponding to the received air pressure signal is equal to or less than a preset air pressure warning threshold value. If the determination result is true (Yes) and it is determined that the air pressure is equal to or lower than the air pressure warning threshold value, the process proceeds to step S34, where a warning signal is issued, and the warning lamp 55 is turned on or blinked. A value for starting the warning and a value for releasing the warning may be provided as the air pressure warning threshold value, and hysteresis may be provided between these values.

  As described above, the air pressure warning threshold value is the same (predetermined value) as the registerable air pressure threshold value, or is larger than the registerable air pressure threshold value. Therefore, the air pressure can be registered by the determination in step S18 of the ID registration control. If it is determined that the threshold value is less than or equal to the threshold value, the determination result is naturally true (Yes), so the process proceeds to step S36, and the warning lamp 55 is turned on or blinked.

  After registering the ID in the ID registration mode, the reduced air pressure of the tires 20, 21, 22, and 23 is returned to the original appropriate air pressure individually or at a time. Then, the receiver 50 determines and grasps which tire air pressure has increased by the ID matching determination in step S32. In step S34, it is determined again whether the air pressure is equal to or lower than the air pressure warning threshold value. The determination result is false (No), and it is determined that the air pressure of the tire in which the air pressure has increased exceeds the air pressure warning threshold value. If it is, the process proceeds to step S38, the warning signal is canceled for each tire or for all tires, and the lighting or blinking of the warning lamp 55 is stopped.

  When the air pressure is returned to the original proper air pressure for all the tires for which the ID registration has been performed, the lighting or blinking of the warning lamp 55 should be stopped at all if the registered ID is correct. However, if the warning signal is not released even though the pressures of all the tires for which ID registration has been performed have been returned to the original proper pressure, the ID signal transmitted for the tire for which the warning signal is not released. And the ID stored in the receiver 50 do not match, and it can be determined that there is a high possibility that the ID is erroneously registered due to disturbance or the like.

As described above, after registering the ID in the ID registration mode, the ID of the transmitters 40, 41, 42, and 43 is easily registered correctly by returning the reduced tire pressure to the original proper pressure. I can confirm that. If the IDs do not match, the ID may be registered again for the corresponding tire.
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. The transmitters 40, 41, 42, and 43 are described as examples, but the tires 20, 21, 22, and 23 may be tube tires. In this case, the transmitter is attached to the valve of each tube. 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.

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. It is a flowchart which shows the control routine of the pneumatic warning 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 (2)

A transmitter that is attached to a tire of a vehicle and detects a tire pressure by a pneumatic sensor and transmits a pneumatic signal, and a warning signal when a signal from the transmitter is received and the tire pressure is below a predetermined value A tire pressure monitoring device having a receiver emitting
The transmitter transmits the ID signal of the transmitter included in the air pressure signal,
When the receiver is in an ID registration state for registering an ID of the transmitter, an ID signal included in the received air pressure signal when the tire air pressure corresponding to the received air pressure signal is equal to or less than the predetermined value. And registering the transmitter having the ID when the tire pressure is equal to or less than the predetermined value and the ID of the transmitter matches the ID registered in the receiver. A tire pressure monitoring device that judges that the tire pressure has decreased and issues a warning signal, and releases the warning signal when the tire pressure exceeds the predetermined value . 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 receiver, and registers the ID of the transmitter when the function code is a code corresponding to the signal transmitted for ID registration claim 1 Symbol placement of the tire pressure monitoring device.

Images