JP5881797B1 - Vehicle antitheft device - Google Patents

Abstract

When a vehicle antitheft device is mounted on a small motorcycle, an antitheft device for a vehicle that rarely gives a warning of authentication code verification failure or a warning that a portable device is not detected is obtained. An in-vehicle device having a transmission circuit, a reception circuit, and a first storage circuit storing a first authentication code, and a portable device having a second storage circuit storing a transmission circuit, a reception circuit, and a second authentication code. And the in-vehicle device wirelessly transmits an authentication code request signal using a long-wave band frequency, and in response, the portable device transmits a second authentication code stored in the second storage circuit to a frequency higher than the long-wave band. After confirming that the second authentication code received by the in-vehicle device matches the first authentication code stored in the first storage circuit of the in-vehicle device, the portable device uses the second authentication code. Is continuously transmitted at predetermined time intervals. [Selection] Figure 1

Description

  The present invention relates to an antitheft device for a vehicle such as a motorcycle having an in-vehicle device and a portable device, and more particularly to an antitheft device for a vehicle capable of detecting misplacement of a portable device and detecting a fall with an inexpensive configuration.

An on-vehicle device mounted on the vehicle has a portable device that transmits an authentication code signal based on an authentication code request signal from the on-vehicle device, and the engine starts when the relationship between the authentication code registered in the on-vehicle device matches. The permitted smart keyless vehicle antitheft device has also been put to practical use in motorcycles. Compared to four-wheeled vehicles, the driver's seat of the two-wheeled vehicle is open to the outside, and there is a possibility that the portable device will be dropped when starting driving or starting when the portable device is left behind, and this can be detected and communicated to the driver is necessary.
In Patent Document 1, an in-vehicle device transmits an authentication code request signal to a portable device at a predetermined transmission cycle, the portable device transmits an authentication code signal upon receipt of the authentication code request signal, and the in-vehicle device verifies the authentication code. There has been proposed a vehicle anti-theft device for performing the authentication code verification and notifying the driver.

Japanese Patent No. 4800138 (FIG. 8, FIG. 9, [0046] to [0061])

  In Patent Document 1, when the main switch is turned on, the vehicle-mounted device starts detecting the portable device by transmitting an authentication code request signal to the portable device at a predetermined transmission cycle. In general, it is necessary for the transmission of the authentication code request signal from the in-vehicle device to the portable device to be almost 100% successful, otherwise the authentication code verification is performed despite the failure in transmitting the authentication code request signal. There is a possibility of warning of failure. On the other hand, when a vehicle antitheft device as described above is mounted on a small two-wheeled vehicle, the price of the vehicle itself is low, and therefore the system price of the vehicle antitheft device is required to be kept low. Among the components of in-vehicle devices, transmitting antennas are relatively expensive, and we want to reduce the cost by adopting small ones. In that case, limit the communicable distance to the area of the driver's seat plus alpha In the worst case, there is a possibility that the authentication code request signal does not reach the portable device due to disturbance or the like, the verification of the authentication code cannot be performed, and the driver is inadvertently issued a warning that the portable device is not detected. It was.

Also, in the case of a motorcycle, the driver's seat is open to the outside, so if a person who is not a regular owner of the motorcycle is sitting in the driver's seat and the authorized owner who owns the portable device corresponding to the vehicle approaches The verification of the authentication code will be carried out, and anyone who is sitting in the driver's seat can start the engine and be stolen. In order to prevent such a situation, the area where the authentication code request signal from the in-vehicle device reaches and the communicable distance should be limited to the area of the driver's seat plus alpha. However, even if the area where authentication communication is possible in the state before engine startup is set to be the driver's seat plus alpha, once the engine is started after authentication, communication is performed for regulator switching noise, ignition noise, etc. As a result, the possible area is reduced, and as a result, the authentication code request signal does not reach the portable device, the verification of the authentication code cannot be performed, and the driver may be inadvertently issued a warning that the portable device is not detected. It was.
The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a vehicle anti-theft device that rarely gives an authentication code verification failure warning or a portable device non-detection warning. It is what.

An antitheft device for a vehicle according to the present invention includes a transmission circuit, a reception circuit, and a first storage circuit in which a first authentication code is stored, and an in-vehicle device mounted on the vehicle,
A portable circuit having a transmission circuit, a reception circuit, and a second storage circuit storing a second authentication code;
The in-vehicle device wirelessly transmits an authentication code request signal, and in response, the portable device wirelessly transmits the second authentication code stored in the second storage circuit, and the second authentication code received by the in-vehicle device is In the anti-theft device for a vehicle that enables the use of the vehicle when it is confirmed that it matches the first authentication code stored in the first storage circuit,
The in-vehicle device wirelessly transmits using a frequency belonging to a long wave band, and the portable device wirelessly transmits using a frequency belonging to a frequency band higher than the long wave band,
After the in-vehicle device confirms that the second authentication code matches the first authentication code, the in- vehicle device does not transmit an authentication code request signal from the in-vehicle device, and the portable device continues the second authentication code at a predetermined time interval. It is for wireless transmission.

  In addition, after a predetermined time has elapsed after the vehicle-mounted device confirms that the second authentication code matches the first authentication code, the time interval for the portable device to wirelessly transmit the second authentication code is increased. is there.

  According to the vehicle antitheft device of the present invention, after confirming the coincidence of the second authentication code and the first authentication code on the in-vehicle device side and starting the engine, the authentication code request signal from the in-vehicle device to the portable device is Since the portable device continues to transmit the second authentication code wirelessly without wireless transmission, even if the area where the authentication code request signal from the in-vehicle device reaches is limited for safety reasons and cost reasons, There is an effect that there is little influence on machine detection.

  In addition, by using the RF band, which has a longer communication distance than the LF band, as a portable device transmission signal, the failure of portable device detection due to regulator noise that has occurred in portable device detection using the conventional LF band can be prevented, and a buzzer can be used without darkness. Will no longer ring and no alarm will be displayed on the instrument panel.

  In addition, the frequency of transmission of the second authentication code signal is set to be high immediately after the end of authentication, which is considered to be likely to cause the mobile device to be left behind or dropped when starting, and thereafter the frequency is decreased with the passage of time. As a result, the battery consumption of the portable device can be reduced.

It is a block diagram which shows the whole structure of the vehicle antitheft device in Embodiment 1 of this invention. 3 is a flowchart illustrating an operation in the first embodiment.

Embodiment 1 FIG.
In FIG. 1, reference numeral 1 denotes an in-vehicle device mounted on the vehicle side of a vehicle antitheft device, which includes a power supply circuit 3 that generates a power supply for an internal control circuit from a voltage supplied from a battery 2. 4 operates. The in-vehicle device 1 includes a transmission circuit 6 and a reception circuit 7 that perform communication with the portable device 20. A specific authentication code (first authentication code) is stored in the storage circuit 5. As an input circuit, a start switch 8 is connected through an interface 31. The warning means 9 is connected to the output circuit through the interface 32, the relay 11 is connected through the interface 33, and the engine control unit 10 is connected through the interface 34 and the communication line 14.

In the engine control unit 10, power is supplied from the battery 2 via the relay 11, and the microcomputer 15 is operated by the voltage generated by the power circuit 12. The vehicle-mounted device 1 is connected through the communication line 14 and the interface 35. A vehicle state confirmation means (various sensors) 16 for confirming the vehicle state is connected to an input circuit of the microcomputer 15 through an interface 36. An actuator 17 for controlling the engine is connected to an output circuit of the microcomputer 15 through an interface 37. Reference numeral 20 denotes a portable device that operates using the battery 24 as a power source and includes a microcomputer 23. Furthermore, a receiving circuit 21 that performs wireless communication with the in-vehicle device 1 and a transmitting circuit 22 are provided. A specific authentication code (second authentication code) is registered in the storage circuit 25. Moreover, in order to manage the passage of time, a passage of time confirmation means 38 is provided. The time elapse confirmation means 38 may use the clock in the microcomputer 23.

  FIG. 2 is a flowchart of the vehicle antitheft device according to the first embodiment of the present invention. The operation of the first embodiment will be described with reference to FIGS. In FIG. 2, it is assumed that the portable device 20 is sleeping before the vehicle is started. In step S1, the driver carrying the portable device 20 switches the start switch 8 of the motorcycle to which the in-vehicle device 1 is attached from OFF to ON. When the start switch 8 is turned on, the process proceeds to step S2, and the in-vehicle device 1 transmits an authentication code request signal to the portable device 20 in an LF (Low Frequency, long wave) band (for example, 30 to 300 kHz) generated by the transmission circuit 6. Is transmitted wirelessly to the portable device 20 through the in-vehicle device transmission signal 18. The portable device 20 receives the in-vehicle device transmission signal 18 by the reception circuit 21, exits the sleep state, and generates a second authentication code stored in the storage circuit 25 by RF (Radio Frequency) issued from the transmission circuit 22. The signal is transmitted to the in-vehicle device 1 through a portable device transmission signal 26 that is a radio wave of a band (for example, an ultra high frequency band, 300 to 3000 MHz). The in-vehicle device 1 receives the second authentication code transmitted from the portable device 20 by the receiving circuit 7 and then collates with the first authentication code stored in the storage circuit 5. If the authentication codes match, the process proceeds to step S3. If the authentication codes do not match, the process proceeds to step S1. In addition, it transfers to step S1, and the vehicle equipment 1 may notify a driver | operator of the mismatch of an authentication code using the warning means 9. FIG.

Since the engine has not been started up to step S3, there is little noise, and relatively stable wireless communication can be performed between the in-vehicle device 1 and the portable device 20 even using radio waves in the LF band. Accordingly, the in-vehicle device 1 can issue a command to move the portable device 20 to step S4 by wireless communication in step S3. In step S4, the portable device 20 transitions to a state in which the second authentication code is wirelessly transmitted from the transmission circuit 22 to the in-vehicle device 1 continuously at predetermined time intervals (for example, 500 ms) according to the command.

  In step S2, the portable device 20 wirelessly transmits the second authentication code, the in-vehicle device 1 collates the second authentication code and the first authentication code, and if the authentication code matches, the portable device 20 The authentication code request signal is not transmitted again. Accordingly, even if the in-vehicle device 1 does not issue the command, the portable device 20 periodically transmits the second authentication code to the in-vehicle device 1 continuously at the predetermined time interval (for example, 500 ms) after a predetermined time has elapsed. You may transition to a state.

  In step S4, since the authentication codes match in step S2, the in-vehicle device 1 turns on the relay 11 at the timing of shifting to step S4, thereby supplying power to the engine control unit and supplying the engine control unit 10 with the power. An engine start permission command can be issued, for example, via the communication line 14 so that the engine can be started. In the state of step S4, the engine is started and the vehicle is about to start running. For example, the portable device 20 is placed on the fuel tank or in the pocket of clothes, but from the half pocket. There is a possibility of falling due to the behavior of the vehicle at the start of running, such as coming out. There is also a possibility that the portable device 20 is left in the garage and starts running. Immediately after the start of traveling, it is considered that there is a high possibility that the portable device 20 will be separated from the driver due to dropping or the like. Therefore, the frequency of RF signal transmission from the portable device 20 for confirming the presence of the portable device 20 is It is set higher. For example, the interval is 500 ms.

  In step S5, the portable device 20 determines whether or not a predetermined time has elapsed after the authentication in step S2 by the time passage confirmation unit 38. For example, if the predetermined time is set to 1 minute, for example, if one minute or more has elapsed, the process proceeds to step S6, and if less than 1 minute, the process proceeds to step S7.

  In step S6, the portable device 20 changes the RF signal transmission cycle from 500 ms to, for example, 5 s. The reason for changing the transmission cycle is that if the predetermined time 1 minute in step S5 has passed, the vehicle has started to move, and the time zone in which the portable device 20 is likely to move away from the driver due to dropping or the like has passed. This is because the power consumption of the portable device 20 is suppressed.

  In step S7, the in-vehicle device 1 receives the RF signal transmitted from the portable device 20, and determines whether the authentication codes match. By placing the transmission cycle information on the RF signal, the in-vehicle device 1 and the portable device 20 can share the transmission cycle interval. If the RF signal is received by the in-vehicle device 1 and the authentication codes match, the process proceeds to step S8, and if they do not match, the process proceeds to step S10.

In step S8, the in-vehicle device 1 determines whether the engine is stopped. The in-vehicle device 1 obtains engine rotation speed information from the engine control unit 10 via the communication line 14, and the in-vehicle device 1 determines whether or not the engine is stopped based on the engine rotation speed information. The engine control unit 10 obtains engine rotational speed information using the vehicle state confirmation means 16. If the in-vehicle device 1 determines that the engine is stopped, it is necessary to stop the RF signal continuously transmitted from the portable device 20, and therefore the process proceeds to step S9. If the engine has not stopped, the operation returns to step S5 in order to continue the operation of confirming the presence of the portable device 20.

  In step S9, when the engine stop is confirmed in step S8, the engine stop information is put on the LF signal transmitted from the vehicle-mounted device 1, and the portable device 20 is notified that the engine has stopped. In this step S9, since the engine has already stopped, there is no fear of LF signal transmission failure due to regulator noise, so the possibility of LF signal transmission failure is low. When the portable device 20 receives the engine stop signal, the transmission of the RF signal from the portable device 20 is stopped in order to suppress the consumption of the battery 24 of the portable device 20.

  In step S10, the in-vehicle device 1 counts the number of times the reception of the RF signal has failed. For example, if three consecutive RF communication failures occur, it is determined that the distance between the in-vehicle device 1 and the portable device 20 is more than the RF communication distance and the portable device 20 has fallen, and the process proceeds to step S11 and the warning means 9 is used. To inform the driver. If the number of RF communication failures is within 2 consecutive times, the process proceeds to step S5. If it is within two times, the portable device 20 may have failed in communication due to other factors even though it has not actually dropped.

  In small motorcycles, the communication distance by LF is minimized to improve theft prevention and cost, and if LF communication is used for portable device detection, there is a possibility of detection failure due to regulator noise. large. Therefore, as in the first embodiment, by using the RF band having a communication distance longer than that of the LF band as the portable device transmission signal, the cellular phone due to the regulator noise generated by the portable device detection using the conventional LF band. Machine detection failure is prevented, and no buzzer sounds or alarms are displayed on the instrument panel.

  The transmission frequency of the second authentication code is likely to cause the mobile device to be left behind or dropped when starting, and the time zone immediately after the end of authentication code authentication is high, and a certain time after the end of authentication, for example, 1 minute passes. For example, the life of the battery 24 of the portable device 20 can be extended by reducing the frequency.

  Although the portable device 20 is in a sleep (low power consumption) state before the vehicle is started, the portable device 20 is activated when receiving the authentication code reception request signal from the in-vehicle device 1, thereby suppressing power consumption and the battery 24 of the portable device 20. Needless to say, it is possible to extend the service life.

  When a portable device is detected, a long communication distance is not required as in answer-back in a keyless entry system. Therefore, an area where the communication distance of RF communication can be sufficiently surrounded, for example, a radius is substantially The life of the battery 24 of the portable device 20 can be extended by limiting the amount of power used by the portable device 20 for RF communication to the inside of the circular area of the vehicle length (about 2 meters). Needless to say.

  The in-vehicle device 1 recognizes that the vehicle is in a stable state (for example, constant speed running) via the communication line 14 by the vehicle state confirmation means 16, and transmits the in-vehicle device in the LF band from the transmission circuit 6 of the in-vehicle device 1 in the previous period. If the portable device 20 is instructed through the signal 18 and is instructed to lengthen the transmission cycle of the portable device transmission signal 26 in the RF band, the portable device 20 determines that a predetermined time has elapsed and controls to increase the RF communication cycle. Compared to the above, it is needless to say that the power consumption of the portable device 20 can be further suppressed and the life of the battery 24 can be extended.

  In the first embodiment, when the engine is stopped, the engine stop information is transmitted from the in-vehicle device 1 to the portable device 20, but the portable device 20 may transmit to the in-vehicle device 1 that the engine stop information has been received. In this case, if the portable device 20 cannot correctly receive the engine stop information, a reply indicating that the engine stop information has been received is not returned, so the in-vehicle device 20 can transmit the engine stop information again.

  Further, in the first embodiment, in step S2, the portable device 20 only transmits the second authentication code on the RF band portable device transmission signal 26 unilaterally to confirm the presence of the portable device 20. However, the in-vehicle device 1 may LF transmit the in-vehicle device transmission signal 18 to the portable device 20 in response to the transmission of the second authentication code of the portable device 20. In this case, even if the portable device 20 repeatedly transmits the portable device transmission signal 26 to the in-vehicle device 1 a plurality of times (for example, 100 times) continuously, the response by the in-vehicle device transmission signal 18 from the in-vehicle device 1 can be detected. If not, the portable device 20 may stop the portable device transmission signal 26 by determining that it is no longer necessary to confirm the presence of the portable device 20 because the engine has stopped.

  In the present invention, the embodiments can be appropriately modified and omitted within the scope of the invention.

  The present invention is applicable not only to motorcycles but also to motorbikes, general automobiles, riding agricultural machines, riding construction machines, or ships using power.

1 on-board device, 2 battery, 3 power supply circuit, 4 microcomputer, 5 memory circuit,
6 transmitter circuit, 7 receiver circuit, 8 start switch, 9 warning means,
DESCRIPTION OF SYMBOLS 10 Engine control unit, 11 Relay, 12 Power supply circuit, 14 Communication line, 15 Microcomputer, 16 Vehicle state confirmation means, 17 Actuator,
18 on-board device transmission signal, 20 portable device, 21 reception circuit, 22 transmission circuit,
23 microcomputer, 24 battery, 25 memory circuit, 26 portable device transmission signal,
31, 32, 33, 34, 35, 36, 37 interface,
38 hours confirmation

Claims (8)

An in-vehicle device having a transmission circuit, a reception circuit, and a first storage circuit in which a first authentication code is stored;
A portable circuit having a transmission circuit, a reception circuit, and a second storage circuit storing a second authentication code;
The in-vehicle device wirelessly transmits an authentication code request signal, and in response, the portable device wirelessly transmits the second authentication code stored in the second storage circuit, and the second authentication code received by the in-vehicle device is In the anti-theft device for a vehicle that enables use of the vehicle when it is confirmed that the first authentication code stored in the first storage circuit matches,
The in-vehicle device wirelessly transmits using a frequency belonging to a long wave band, and the portable device wirelessly transmits using a frequency belonging to a frequency band higher than the long wave band,
After the in-vehicle device confirms that the second authentication code matches the first authentication code, the in- vehicle device does not transmit an authentication code request signal from the in-vehicle device, and the portable device continues the second authentication code at a predetermined time interval. An antitheft device for a vehicle characterized by wireless transmission.   After the vehicle-mounted device confirms the match between the second authentication code and the first authentication code, the time interval over which the portable device wirelessly transmits the second authentication code is increased after a predetermined time has passed. The vehicle antitheft device according to claim 1.   After a predetermined time has elapsed after the in-vehicle device has confirmed that the second authentication code matches the first authentication code, the time interval for the portable device to wirelessly transmit the second authentication code increases with time. The vehicle antitheft device according to claim 1 or 2, wherein the antitheft device for a vehicle is used.   The portable device is in a sleep state before starting the vehicle, and when the in-vehicle device wirelessly transmits the authentication code request signal, the portable device is activated and transmits a second authentication code to the in-vehicle device. The vehicle antitheft device according to any one of claims 1 to 3.   The communication distance between the in-vehicle device and the portable device that allows the in-vehicle device to receive the second authentication code transmitted from the portable device is substantially within the length of the vehicle. The vehicle antitheft device according to any one of claims 1 to 4.   2. The wireless communication apparatus according to claim 1, wherein an authentication code stop request signal is wirelessly transmitted from the in-vehicle device when the engine of the vehicle is stopped, and the portable device stops wireless transmission of the second authentication code accordingly. The vehicle antitheft device according to any one of claims 5 to 6.   After the vehicle-mounted device confirms the match between the second authentication code and the first authentication code, when the vehicle-mounted device cannot continuously receive the signal of the second authentication code wirelessly transmitted by the portable device for a predetermined time or longer, The vehicle antitheft device according to any one of claims 1 to 6, further comprising warning means for warning a person who has dropped or lost the portable device.   After the vehicle-mounted device confirms that the second authentication code matches the first authentication code, the portable device receives the second authentication code wirelessly transmitted at a predetermined time interval as a result of the predetermined time. A warning means for warning a driver that the portable device is dropped or lost when the second authentication code and the first authentication code do not coincide with each other for a predetermined number of times at intervals. The vehicle antitheft device according to any one of claims 1 to 7.