JP4816933B2 - Tire / wheel theft detection device - Google Patents

Description

  The present invention relates to a tire / wheel theft detection device for detecting a theft of a tire / wheel in a vehicle and issuing an alarm.

  Conventionally, since tires and wheels of vehicles are mounted on the outside of the vehicle body, they can be easily removed and are relatively easily stolen.

  As a device for preventing theft of such a car or tire / wheel, for example, a tire condition monitoring device disclosed in Japanese Patent Laid-Open No. 2000-203219 (Patent Document 1) or Japanese Patent Laid-Open No. 8-244559 is disclosed. The vehicle antitheft device disclosed in Japanese Patent Publication (Patent Document 2), the vehicle antitheft device disclosed in Japanese Patent Application Laid-Open No. 2002-362318 (Patent Document 3), and Japanese Patent Application Laid-Open No. 2003-300452 (Patent Document 4). A vehicle tire monitoring device disclosed, and a communication system and a wheel-side communication device for notifying wheel theft disclosed in JP 2006-88819 A (Patent Document 5) are known.

  A tire condition monitoring device disclosed in Patent Document 1 includes a sensor that measures a physical quantity in a tire, a transmitter that transmits data from the sensor, a control circuit that controls operations of the sensor and the transmitter, A power source that supplies power to the control circuit; a vibration switch that detects vibrations of the tire; and a receiver that receives data transmitted from the transmitter, and the control circuit collects data by the sensor when vibrations occur. And data transmission by the transmitter.

  The vehicle antitheft device disclosed in Patent Document 2 responds to an air pressure sensor that detects the air pressure of a vehicle wheel, a means for detecting the parking state of the vehicle, an output of the air pressure sensor, and an output of the parking state detection means. And means for generating an alarm signal when the air pressure falls below a predetermined value during parking, and even if the tow truck is moved without tilting the vehicle while the vehicle is parked. A signal can be generated.

  A vehicle theft detection device disclosed in Patent Document 3 includes a theft detection state setting means for setting whether or not a vehicle being monitored is in an operation state for detecting theft, and tire air attached to a tire of the vehicle Tire air pressure abnormality detection means for sending a tire air pressure abnormality detection signal when the air pressure detected by the pressure sensor changes more than a predetermined amount below a predetermined air pressure, and on the ground surface of the vehicle The vehicle position movement detecting means for monitoring a planar position by GPS and sending a vehicle position movement signal when the vehicle moves beyond a predetermined distance and the theft detection state setting means are in the operating state. In the case, the tire air pressure abnormality detecting means sends out a tire air pressure abnormality signal, and the vehicle position movement detecting means sends out the vehicle position movement signal. A vehicle theft determination means for determining that the vehicle has been stolen, and a car telephone apparatus for notifying the occurrence of theft of the vehicle to a preset theft report destination when the vehicle theft determination means determines that the theft has occurred In addition, the vehicle theft can be detected and the stolen vehicle can be tracked.

A communication system for notifying wheel theft disclosed in Patent Document 4 includes a vehicle body side communication device arranged on a vehicle body of a vehicle, and a wheel side arranged on a wheel of the vehicle or a tire attached to the wheel. In the communication system including the communication device, the vehicle body side communication device travels by repeatedly transmitting the acquired travel distance of the host vehicle to the wheel side communication device, and a travel distance acquiring unit that acquires the travel distance of the host vehicle. A distance transmission means and a theft notification means for outputting a wheel theft notification based on receiving a mismatch signal transmitted from the wheel side communication device, the wheel side communication device at different times The inconsistency signal is transmitted to the vehicle body side communication device based on the fact that the travel distances transmitted from the wheel side communication device are separated from each other by a predetermined reference or more. In Shin system, in which the wheel when the theft wheel is mounted on the vehicle so as to notify to detect that it is a stolen article.
JP 2000-203219 A JP-A-8-244559 JP 2002-362318 A JP 2006-88819 A

  However, since the tire condition monitoring device disclosed in Patent Document 1 can only detect vibration in one direction due to the structure of the vibration sensor, when only vibration in a direction that cannot be detected by the vibration sensor occurs during tire theft, The theft cannot be detected.

  Moreover, in the antitheft device for a vehicle disclosed in Patent Document 2, there is a risk of malfunction when the tire air pressure changes due to a change in ambient temperature.

  Similarly, the vehicle theft detection device disclosed in Patent Document 3 may cause a malfunction when the tire air pressure changes due to a change in ambient temperature.

  In the communication system disclosed in Patent Document 4, since a means for acquiring the travel distance of the vehicle as information is required, it is troublesome to attach to the existing vehicle and the cost is increased.

  The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a tire / wheel theft detection device that can be easily attached to an existing vehicle while suppressing the occurrence of malfunction.

In order to achieve the above object, the present invention is a tire / wheel theft detection device comprising a detection unit provided on each tire / wheel of a vehicle and a monitoring unit provided on a vehicle body, wherein the detection unit comprises: , An acceleration that detects a first acceleration generated in the tire rotation direction, a second acceleration generated in the tire rotation axis direction, and a third acceleration generated in a direction perpendicular to the tire rotation axis and outputs an electrical signal corresponding to each acceleration. A sensor, and transmission means for transmitting information on the first acceleration, the second acceleration, and the third acceleration by radio waves based on an electrical signal output from the acceleration sensor, and the monitoring unit includes each tire wheel Receiving means for receiving the radio wave transmitted from the detection unit provided in the first and second radio waves from the radio wave received by the receiving means. Information extracting means for extracting information relating to acceleration and third acceleration, and information relating to a change pattern of the first acceleration, the second acceleration, and the third acceleration within a predetermined time when the vehicle is running and when the vehicle is stopped are stored. Storage means, and information on a change pattern within a predetermined time of the third acceleration stored in the storage means, with reference to information on the third acceleration when the vehicle is stopped stored in the storage means, third compares the information relating to the change pattern in a predetermined time period of the acceleration extracted by the information extraction means, the third acceleration change pattern is unacceptable variation pattern in predetermined time extracted by the information extraction means judging means for judging whether or is the result of the determination of the determination means, the third acceleration extracted by the information extraction means When the change pattern in the predetermined time is a variation pattern out of tolerance, based on the information on the first acceleration and the second acceleration at the time of vehicle stored in the storage means, stored in said storage means and the first acceleration and the information on the change patterns within a predetermined time of the second acceleration, and information on the change pattern in the information extraction first acceleration and a predetermined time of the second acceleration that has been extracted by means compares the A tire equipped with alarm means for issuing a theft alarm when the change pattern of either the first acceleration or the second acceleration extracted by the information extracting means is a change pattern outside the allowable range; A wheel theft detection device is proposed.

  The tire / wheel theft detection device of the present invention detects first to third accelerations generated in three directions orthogonal to each other, and based on a change pattern of these accelerations within a predetermined time, Detects wheel theft and issues a theft alarm.

  According to the tire / wheel theft detection device of the present invention, the attachment of the device can be easily completed by attaching the detection unit to each tire / wheel and attaching the monitoring unit to the vehicle body. Furthermore, the first to third accelerations generated in the three directions orthogonal to each other are detected, and the theft of the tire and the wheel when the vehicle is stopped is detected based on the change pattern of these accelerations within a predetermined time. Thus, no malfunction occurs as in the conventional example.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  In the present embodiment, an example in which the tire / wheel theft detection device of the present invention is mounted on a four-wheel vehicle will be described as an example.

  FIG. 1 is an external view showing the arrangement of detection units and monitoring units according to an embodiment of the present invention, FIGS. 2 and 3 are diagrams illustrating the installation location of the detection unit on a tire according to an embodiment of the present invention, and FIG. FIG. 5 is a block diagram showing a configuration of a detection unit in one embodiment of the present invention, and FIG. 5 is a block diagram showing a configuration of a monitoring unit in one embodiment of the present invention.

  1 to 3, 1 is a vehicle, 2 is a tire (wheel), 3 is an axle, 4 is a tire house, 100 is a detection unit, and 200 is a monitoring unit. In the present embodiment, in each of the detection unit 100 and the monitoring unit 200, each electric system circuit is housed in a small casing having insulation and electromagnetic wave transmission, and each of the four detection units 100 is a tire of the vehicle 1. 2 and one monitoring unit 200 is arranged in the vicinity of the driver's seat. In the present embodiment, the detection unit 100 and the monitoring unit 200 constitute the tire / wheel theft detection device of the present invention.

  The tire 2 is, for example, a known tubeless radial tire, and includes a wheel and a rim in the present embodiment. The tire 2 includes a tire main body 305, a rim 306, and a wheel 307. The tire main body 305 includes a known cap tread 301, under tread 302, belts 303A and 303B, carcass 304, and the like. In the present embodiment, as shown in FIG. 3, the tire 2 includes a detection unit 100, and the detection unit 100 is fixed to the rim 306.

  In the present embodiment, the following description will be made assuming that the rotation direction of the tire 2 is the X-axis direction, the rotation axis direction of the tire 2 is the Y-axis direction, and the radial direction centering on the rotation axis of the tire 2 is the Z-axis direction. In the present embodiment, the detection unit 100 is fixed to the rim 306 of the tire 2. However, the attachment position of the detection unit 100 is not limited to the rim 306, and may be any part of the tire / wheel. Good.

  As shown in FIG. 4, the detection unit 100 includes a triaxial acceleration sensor 101, a microprocessor 102, a transmission circuit 103, an antenna 104, and a battery 105.

  The triaxial acceleration sensor 101 is centered on the first acceleration generated in the X axis direction that is the rotation direction of the tire 2, the second acceleration generated in the Y axis direction that is the rotation axis direction of the tire 2, and the rotation axis of the tire 2. One sensor element (not shown) that detects each third acceleration generated in the Z-axis direction, which is the radial direction, and outputs it as an electric signal, and for each direction based on the electric signal output from this sensor element And an interface unit (not shown) for outputting information corresponding to the acceleration value to the microprocessor 102. In this embodiment, the acceleration in the X, Y, and Z axis directions is detected by one sensor element, but the acceleration in the X, Y, and Z axis directions is detected by using two or more sensor elements. May be.

  The microprocessor 102 is mainly composed of a well-known CPU, and includes a memory for storing a program for operating the CPU, an arithmetic memory, and the like. Further, the microprocessor 102 inputs acceleration information in each direction from the triaxial acceleration sensor 101, for example, every 3 seconds, accumulates this information corresponding to the passage of time, and stores this information as a digital signal in a predetermined format. And output to the transmission circuit 103 every predetermined time, for example, every 3 minutes.

  The transmission circuit 103 transmits the digital signal input from the microprocessor 102 from the antenna 104 by a radio wave of a predetermined frequency, for example, a radio wave of 315 MHz.

  The battery 105 supplies driving power to each of the three-axis acceleration sensor 101, the macro processor 102, and the transmission circuit 103.

  As shown in FIG. 5, the monitoring unit 200 includes an antenna 201, a receiving circuit 202, a microprocessor 203, a display circuit 204, an alarm buzzer 205, an alarm lamp 206, a storage unit 207, and a DC / DC conversion circuit 208. ing.

  The receiving circuit 202 receives the radio wave transmitted from the detection unit 100 via the antenna 201, reproduces the acceleration information in the X, Y, and Z axis directions as a digital signal and outputs it to the microprocessor 203.

  The microprocessor 203 inputs acceleration information from the receiving circuit 202, obtains acceleration change patterns in the X, Y, and Z axis directions within the predetermined time, and stores the Z axis direction acceleration change patterns in the storage unit 207. The acceleration change patterns in the X-axis direction and the Y-axis direction are stored in the storage unit 207 as the possibility that the theft has occurred when the change pattern exceeds the allowable range compared to the change pattern being recorded. It is determined that the theft of the tire 2 has occurred when the change pattern exceeds the allowable range compared with the stored change pattern, the character “theft has occurred” is displayed on the display circuit 204, and a warning is given. The buzzer 205 is sounded and the alarm lamp 206 is turned on to notify the occurrence of theft.

  The storage unit 207 stores a plurality of types of information related to change patterns within a predetermined time of acceleration in the X-, Y-, and Z-axis directions when the vehicle is stopped and when the vehicle is traveling, which is obtained by measuring in advance. 6 to 10 are diagrams showing the main part of an acceleration change pattern as an example of the change patterns stored in the storage unit 207. FIG. 6 is a diagram showing an acceleration change pattern in the X, Y, and Z-axis directions when the vehicle is stopped when the detection unit 100 is stopped at the 0 degree position shown in FIG. 3, and FIG. 7 is a diagram showing 90 degrees that the detection unit 100 shows in FIG. FIG. 8 is a diagram showing an acceleration change pattern in the X, Y, and Z-axis directions when the vehicle is stopped at the position of FIG. 8, and FIG. 8 is a diagram illustrating X, Y, when the vehicle is stopped when the detection unit 100 is stopped at the position of 180 degrees shown in FIG. FIG. 9 is a diagram showing an acceleration change pattern in the Z-axis direction, FIG. 9 is a diagram showing an acceleration change pattern in the X, Y, and Z-axis directions when the vehicle is stopped when the detection unit 100 is stopped at the position of 270 degrees shown in FIG. These are figures which show the acceleration change pattern of a X, Y, Z-axis direction at the time of vehicle travel. In these figures, the horizontal axis represents time, and the vertical axis represents acceleration. In the figure, a curve indicated by X represents an acceleration change pattern in the X-axis direction, a curve indicated by Y represents an acceleration change pattern in the Y-axis direction, and a curve indicated by Z represents an acceleration change pattern in the Z-axis direction. Represents.

  When the vehicle is stopped, the acceleration in each of the X, Y, and Z axis directions does not change with time and has a change pattern that is almost a straight line. Further, when the vehicle travels, the acceleration change pattern shown in FIG. 10 is obtained while the tire 2 makes one revolution. FIG. 11 shows an example of an acceleration change pattern when the tire 2 is removed when the vehicle is stopped. As shown in FIG. 11, when the tire 2 is removed, a completely different acceleration change pattern is obtained when the vehicle is stopped and when the vehicle is running.

  The DC / DC conversion circuit 208 is supplied with electric power from an in-vehicle DC power supply (not shown), and receives this voltage from the reception circuit 202, the microprocessor 203, the display circuit 204, the alarm buzzer 205, the alarm lamp 206, and the storage unit 207. Each of them is converted into a driving voltage and supplied with driving power.

  Next, the operation of the tire / wheel theft detection apparatus according to this embodiment having the above-described configuration will be described with reference to the flowcharts shown in FIGS. The flowchart of FIG. 12 represents processing performed by the microprocessor 102 of the detection unit 100, and the flowchart of FIG. 13 represents processing performed by the microprocessor 203 of the monitoring unit 200.

  When the operation starts, the microprocessor 102 of the detection unit 100 clears the accumulated information (SA1) and resets the timer time T to 0 (SA2). As described above, for example, every three seconds from the triaxial acceleration sensor 101. The acceleration information in the X-axis direction, the Y-axis direction, and the Z-axis direction is acquired and stored corresponding to the passage of time (SA3).

  Next, the microprocessor 102 determines whether or not the timer time T has exceeded a predetermined time, for example, 3 minutes (SA4). When 3 minutes have not elapsed, the microprocessor 102 proceeds to the processing of SA3. The accumulated acceleration information is converted into a predetermined format and transmitted through the transmission circuit 103 (SA5).

  On the other hand, when the operation starts, the monitoring unit 200 receives the acceleration information transmitted from the detection unit 100 (SB1), and the vehicle stored in the storage unit 207 and the acceleration change pattern in the Z-axis direction based on the received information. The acceleration change pattern in the Z-axis direction at the time of stopping and traveling is compared (SB2), and the change pattern of the Z-axis direction acceleration is different from the allowable range compared with the change pattern stored in the storage unit 207. It is determined whether or not (SB3).

  As a result of the determination, when the change pattern of the acceleration in the Z-axis direction is not different from the allowable range as compared with the change pattern stored in the storage unit 207, the process proceeds to SB1.

  Further, as a result of the determination of SB3, when the change pattern of the acceleration in the Z-axis direction is different from the change pattern stored in the storage unit 207 exceeding the allowable range, the theft may have occurred. Therefore, the acceleration change patterns in the X-axis direction and the Y-axis direction are compared with the change patterns stored in the storage unit 207 (SB4), and the acceleration change patterns in the X-axis direction and the Y-axis direction are stored in the storage unit. It is determined whether or not the change pattern exceeds the allowable range compared with the change pattern stored in 207 (SB5).

  As a result of this determination, if the acceleration change patterns in the X-axis direction and the Y-axis direction are not different from the allowable range compared to the change patterns stored in the storage unit 207, it is assumed that no theft has occurred. The process proceeds to step SB1.

  If the acceleration change pattern in the X-axis direction and the Y-axis direction is different from the change pattern stored in the storage unit 207 beyond the allowable range as a result of the determination in SB5, the tire 2 is stolen. It is assumed that an act has occurred. The display circuit 204 displays the word “theft occurred” (SB6), further sounds the alarm buzzer 205 (SB7) and lights the alarm lamp 206 (SB8). Announce the occurrence.

  As described above, in this embodiment, the apparatus can be easily attached by mounting the detection unit 100 on the tire 2 and installing the monitoring unit 200 in the vicinity of the driver's seat of the vehicle. Further, accelerations in the X, Y, and Z axis directions generated in the three directions orthogonal to each other are detected, and the tire 2 (tire / wheel) when the vehicle is stopped based on a change pattern of these accelerations within a predetermined time. Since the theft is detected, no malfunction occurs as in the prior art.

1 is an external view showing the arrangement of detection units and monitoring units in an embodiment of the present invention. The figure explaining the installation place of the detection unit to the tire in one embodiment of the present invention The figure explaining the installation place of the detection unit to the tire in one embodiment of the present invention The block diagram which shows the structure of the detection unit in one Embodiment of this invention. The block diagram which shows the structure of the monitoring unit in one Embodiment of this invention. The figure which shows the principal part of the acceleration change pattern as an example in one Embodiment of this invention. The figure which shows the principal part of the acceleration change pattern as an example in one Embodiment of this invention. The figure which shows the principal part of the acceleration change pattern as an example in one Embodiment of this invention. The figure which shows the principal part of the acceleration change pattern as an example in one Embodiment of this invention. The figure which shows the principal part of the acceleration change pattern as an example in one Embodiment of this invention. The figure which shows an example of the acceleration change pattern when removing a tire when a vehicle stops The flowchart showing the process which the microprocessor of the detection unit in one Embodiment of this invention performs The flowchart showing the process which the microprocessor of the monitoring unit in one Embodiment of this invention performs

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Vehicle, 2 ... Tire, 3 ... Axle, 4 ... Tire house, 100 ... Detection unit, 101 ... Three-axis acceleration sensor, 102 ... Microprocessor, 103 ... Transmission circuit, 104 ... Antenna, 105 ... Battery, 201 ... Antenna 202 ... Receiving circuit 203 ... Microprocessor 204 ... Display circuit 205 ... Alarm buzzer 206 ... Alarm light 207 ... Storage unit 208 ... DC / DC conversion circuit 301 ... Cap toledo 302 ... Under tread 303A , 303B ... belt, 304 ... carcass, 305 ... tire body, 306 ... rim, 307 ... wheel.

Claims (2)

A tire / wheel theft detection device comprising a detection unit provided on each tire / wheel of a vehicle and a monitoring unit provided on the vehicle body,
The detection unit is
An acceleration sensor that detects a first acceleration generated in the tire rotation direction, a second acceleration generated in the tire rotation axis direction, and a third acceleration generated in a direction perpendicular to the tire rotation axis and outputs an electrical signal corresponding to each acceleration. When,
Transmission means for transmitting information on the first acceleration, the second acceleration, and the third acceleration by radio waves based on the electrical signal output from the acceleration sensor;
The monitoring unit is
Receiving means for receiving radio waves transmitted from the detection unit provided in each tire and wheel;
Information extracting means for extracting information on the first acceleration, the second acceleration, and the third acceleration from the radio wave received by the receiving means;
Storage means for storing information relating to a change pattern of the first acceleration, the second acceleration, and the third acceleration within a predetermined time when the vehicle is running and when the vehicle is stopped
Extracted by the information extraction means and information on a change pattern of the third acceleration stored in the storage means within a predetermined time with reference to the information on the third acceleration when the vehicle is stopped stored in the storage means by comparing the information on the change pattern in the predetermined time period of the third acceleration is, whether the third acceleration change pattern within a predetermined time that is extracted by the information extraction means is a change in the pattern of unacceptable Determining means for determining
As a result of the determination by the determination means , when the change pattern within a predetermined time of the third acceleration extracted by the information extraction means is a change pattern outside the allowable range, the vehicle storage time stored in the storage means With reference to information on the first acceleration and the second acceleration, information on a change pattern of the first acceleration and the second acceleration stored in the storage unit within a predetermined time, and the first acceleration extracted by the information extraction unit When comparing the information relating to the change pattern in a predetermined time of the second acceleration, the first acceleration or any acceleration of the change pattern is out of the allowable range changing pattern of the second acceleration that has been extracted by said information extraction means A tire / wheel theft detection device comprising: alarm means for issuing a theft alarm when   The tire / wheel theft detection device according to claim 1, wherein the acceleration sensor includes one sensor element.

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