JP3663375B2 - Immobilizer and how to prevent forgetting to remove key with immobilizer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an immobilizer for preventing theft of a vehicle by communicating with a transponder built in a key and identifying whether or not a key used for starting an engine is a specific one. The present invention relates to an immobilizer that can prevent a driver from forgetting to remove a key.
[0002]
[Prior art]
In general, a key removal forget prevention device in an automobile (four-wheel vehicle) includes a cylinder side sensor provided in a key cylinder for detecting the presence or absence of a key, and a door side sensor for detecting that a driver side door is opened. When the door is opened with the key inserted into the key hole by these sensors, it is recognized that the key has been forgotten and a warning is given to the driver by a buzzer.
[0003]
[Problems to be solved by the invention]
However, the conventional keying forgetting prevention device has the following problems when it is applied to a motorcycle. That is, in the above device, it is a condition that the door side sensor detects that the door has been opened. On the other hand, there is no door in a motorcycle, and rainwater or the like hits a key cylinder directly in a motorcycle. Forgetting to remove the key because the installation of the side sensor is difficult, and because there is not much space near the key cylinder in a motorcycle, it is difficult to install a separate cylinder side sensor. Is not applicable to motorcycles.
[0004]
On the other hand, immobilizers for preventing theft of vehicles by communicating with the transponder built in the key and identifying whether the key used to start the engine is a specific one are also popular in motorcycles However, even if such an immobilizer is provided, the crime prevention effect is significantly reduced if the key is forgotten to be removed. That is, when the engine is started, the immobilizer is configured to communicate with the transponder to identify whether the key is proper for the vehicle, and start the engine on the condition that the key is valid. Therefore, if a legitimate key is stolen, the crime prevention effect will be meaningless.
[0005]
In this way, prevention of forgetting to remove the key is important in preventing theft of motorcycles. Considering the recent increase in theft in motorcycles and the improvement of crime prevention awareness, more and more prevention devices for forgetting to remove keys have been added to motorcycles. It is necessary to provide it.
[0006]
  The present invention has been made in view of such circumstances. By providing the immobilizer with a function to prevent forgetting to remove the key, the forgetting to remove the key can be effectively prevented even in a two-wheeled vehicle, thereby preventing theft of the vehicle. The effect can be further improvedAt the same time, the battery life of the vehicle can be improved.It is an object of the present invention to provide an immobilizer and a method for preventing forgetting to remove a key using the immobilizer.
[0007]
[Means for Solving the Problems]
  According to the first aspect of the present invention, wireless communication is performed with a transponder built in a key used for starting an engine of a vehicle, and it is determined whether the key is unique to the vehicle based on information of the transponder. In the immobilizer for preventing theft of the vehicle, the communication presence / absence detection means for detecting the presence / absence of communication of the communication unit wirelessly communicating with the transponder, the off state detection means for detecting the off state of the main switch, When the communication presence / absence detecting means detects communication with the transponder and the off state detecting means detects that the main switch is turned off, it recognizes that the key has been forgotten to be removed. Recognizing means, and warning means for warning the driver when the recognizing means recognizes that the key has been forgotten to be removed,If the communication presence / absence detecting means does not detect communication with the transponder, the current supply of the immobilizer itself is stopped.It is characterized by that.
[0008]
  According to such a configuration, the recognition means is provided on condition that the communication means presence / absence detection means detects that there is communication with the transponder and the off-state detection means detects that the main switch is off. Recognize forgetting to remove the key and warn the driver with warning means.If communication with the transponder is not detected, the current supply of the immobilizer itself is stopped.
[0009]
The invention according to claim 2 includes a timer for detecting that a predetermined time elapses after the main switch is turned off, and the recognition means detects the presence / absence of communication by the communication presence / absence detection means, and the off In addition to the detection of the main switch being turned off by the state detection means, it is recognized that the key has been forgotten to be removed, on condition that the timer has detected that a predetermined time has elapsed.
[0010]
According to such a configuration, the timer detects that a predetermined time has elapsed in the detection of the communication with the transponder by the communication means presence / absence detection means and the detection of the off state of the main switch by the off state detection means. Based on the detection condition, the recognition means recognizes that the key has been forgotten and the warning means warns the driver.
[0011]
The invention according to claim 3 is characterized in that the timer detects that the warning by the warning means elapses for a predetermined time, and the warning is stopped by the detection.
[0013]
  Claim4The described invention performs wireless communication with a transponder built in a key used for starting an engine of a vehicle, determines whether the key is unique to the vehicle based on information of the transponder, A method for preventing forgetting to remove a key by an immobilizer for preventing theft of a key, and detecting that communication with the transponder is detected, and when the main switch is turned off, the key is forgotten to be removed. And warn the driverAt the same time, when the communication with the transponder is not detected, the current supply of the immobilizer itself is stopped.It is characterized by that.
[0014]
  Claim5The described invention is characterized in that when there is communication with the transponder and the main switch is turned off for a predetermined time, it is recognized that the key is forgotten to be removed.
[0015]
  Claim6The described invention is characterized in that the warning is stopped when a warning for the driver has passed for a predetermined time.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings.
The immobilizer according to the present embodiment is for identifying whether or not the key KY used for starting the engine is a specific one based on the information of the transponder T built in the key KY for a motorcycle. 2, a CPU (Central Processing Unit) 2, a communication unit 3, a communication interface (communication I / F) 4, an EEPROM (Electrically Erasable and Programmable Read Only Memory) 5, a power supply unit 6, and a timer 7. And the antenna 8, the off state detection means 17, and the communication presence / absence detection means 18.
[0018]
The communication unit 3 modulates information transmitted from the CPU 2 and transmits the modulated radio signal to the transponder T side via the antenna 8, while transmitting the radio signal transmitted from the transponder T side via the antenna 8. Are received, demodulated, and sent to the CPU 2. A power switch 21 is provided between the communication unit 3 and the VDD 20 so that the power of the communication unit 3 can be controlled to be turned on / off by an instruction from the CPU 2.
[0019]
The communication I / F 4 is connected to the CPU 2 via a bus, mediates communication between the CPU 2 and the engine control unit 9, and matches the signal level and signal format between them. In order to make it difficult for the communication between the two to be decoded from the outside, for example, it is preferable to make the communication complicated by a serial signal based on an RS-232C-compliant signal, for example, an I / O signal with only high and low levels, etc. It may be a communication form.
[0020]
The EEPROM 5 is a storage means connected to the CPU 2 and stores start time data to be described later, an encryption key that is information unique to the key KY, and the like. Based on the information stored in the EEPROM 5, random number data and an authentication code (both will be described later) are generated. The storage means used here is other nonvolatile storage such as EPROM (Erasable and Programmable Read Only Memory), OTP (One Time Programmable Read Only Memory), or flash EEPROM instead of the EEPROM of this embodiment. It can be a means.
[0021]
The power supply unit 6 generates VDD 20, which is a DC power supply for operating the immobilizer 1, from the battery 22, and is connected to the battery 22 through a main switch 24 provided in the key cylinder 23. The main switch 24 is configured to be turned on when the key KY is inserted into the key cylinder 23 and rotated to the operating position.
[0022]
The timer 7 includes a timer circuit, and detects that a predetermined time has elapsed after the main switch 24 is turned off and the buzzer 10 starts to sound. That is, the time when the main switch 24 is turned off or the time when the buzzer 10 starts to sound is counted as an initial value, and the time when the predetermined time (for example, about 30 seconds to 1 minute) is reached is detected. . Such detection is transmitted to the recognition means 18 described later.
[0023]
The antenna 8 is composed of a coil provided on the upper part of the key cylinder 23 (for example, the outer periphery of the key hole), and transmits a radio signal modulated by the communication unit 3 to the transponder T side or from the transponder T. The received signal is received. That is, the transponder T and the immobilizer 1 can be wirelessly communicated by radio waves (low frequency radio waves), but may be communication by other means such as infrared communication. In this case, the antenna 8 formed of a coil is used. Instead of this, a light transmitting / receiving element is provided.
[0024]
The CPU 2 is for controlling the operation of the immobilizer 1 as a whole with the engine control unit 9 mounted on the vehicle. As shown in FIG. 3, the CPU 2 mainly includes a start control unit 11 and an end. The control unit 12 can be divided into two types. The start control unit 11 is a part that should be controlled mainly when the engine is started, and the end control part 12 is a part that should be controlled mainly when the engine is stopped.
[0025]
The start control unit 11 is a part for identifying by authentication whether or not the key KY used for starting the engine is a specific one (a regular key KY for the vehicle). As shown in FIG. The generation unit 13, the transmission data generation unit 14, the authentication code generation unit 15, and the authentication unit 16 are mainly configured. The transmission data generation means 14 and authentication means 16 are electrically connected to the communication unit 3, and the random number generation means 13 and authentication code generation means 15 are electrically connected to the EEPROM 5, respectively, so that signals can be transmitted and received.
[0026]
The random number generation means 13 generates, for example, 10-digit random number data based on the start time data stored in the EEPROM 5. The start time data is data obtained by measuring the time from the previous operation start of the immobilizer 1 to the engine start by time measuring means (not shown) realized by software, and is stored in the EEPROM 5 in advance. Incidentally, when the engine is started for the first time after the vehicle is produced, it is treated as time 0 data.
[0027]
The transmission data generating unit 14 adds information for limiting the vehicle type to the random number data generated by the random number generating unit 13 (for example, adding a two-digit password for limiting the vehicle type to the head of the random number data). Thus, transmission data to be transmitted from the communication unit 3 to the transponder T is generated. Note that the random number data obtained by the random number generator 13 may be directly transmitted to the communication unit 3 without adding a password as described above.
[0028]
The authentication code generation unit 15 encrypts the transmission data (password + random number data) obtained by the transmission data generation unit 14 using an encryption key that is information unique to the key KY stored in the EEPROM 5 to thereby authenticate the authentication code. Is generated. The encryption method is the same as that used in the transponder T described later.
[0029]
The authentication means 16 compares the authentication key generated and transmitted by the transponder T with the authentication code obtained by the authentication code generation means 15 and, on condition that they match, the engine control unit via the communication I / F 4 9 sends an engine start permission signal. The engine control unit 9 that has received the engine start permission signal sends a confirmation signal notifying that the engine has actually started to the immobilizer 1 after starting the engine of the vehicle, and this time (starting time data) Is stored in the EEPROM 5.
[0030]
The end control unit 12 is a part for preventing forgetting to remove the key KY after the main switch 24 is turned off. The end control unit 12 is a predetermined signal to the off state detection unit 17, the communication presence / absence detection unit 19, the timer 7, and the buzzer 10. It is mainly comprised from the recognition means 18 which can transmit / receive. The off state detection means 17 is electrically connected to the power supply unit 6 (or the main switch 24), the recognition means 18 is electrically connected to the timer 7 and the buzzer 10, and the communication presence / absence detection means 19 is electrically connected to the communication unit 3, respectively. Signal transmission / reception is possible.
[0031]
The off-state detecting means 17 detects the off-state of the main switch 24. When the main switch 24 is turned off, the off-state detecting means 17 detects that the power supply from the battery 22 to the power source unit 6 is lost, or switches the main switch 24. The state itself is configured to be detected by a sensor. That is, it is only necessary to detect that the driver rotates the key KY in the key cylinder 23 and sets it to the stop position when the engine is stopped. In addition, when the OFF state of the main switch 24 is detected, the timer 7 operates so that a predetermined time from the OFF state can be detected.
[0032]
The communication presence / absence detection means 19 detects the presence / absence of communication between the communication unit 3 and the transponder T. For example, the presence / absence of communication can be detected based on whether the modulation / demodulation operation of the communication unit 3 is performed. It is configured. That is, when the key KY is removed from the key cylinder 23 and communication between the transponder T and the antenna 8 is interrupted, it can be detected that communication has been lost, and otherwise communication can be detected. It is composed.
[0033]
The recognizing means 18 detects when the communication presence / absence detecting means 19 is communicating with the transponder T, while the off state detecting means 17 detects that the main switch 24 is turned off. When it is detected that time (for example, 30 seconds) has elapsed, it is recognized that the key KY has been forgotten to be removed from the key cylinder 23. When the forgetting to remove state is recognized, a signal for sounding the buzzer is transmitted from the recognition means 18 to the buzzer 10, and the driver can warn the driver of forgetting to remove the key.
[0034]
The timer 7 is also activated when the recognition means 18 transmits a signal to sound the buzzer 10, and the buzzer 10 is stopped when a predetermined time (for example, 1 minute) has elapsed. That is, the buzzer 10 is operated only for a certain period of time, for example, about 1 minute, and then stops by a signal from the recognition means 18. As a result, the power consumption due to the operation (warning) of the buzzer 10 can be reduced, the life of the battery 22 can be improved, and noise to the surroundings can be minimized.
[0035]
In the immobilizer 1 according to the present invention, it is necessary to keep the power switch 21 closed at all times and supply a current to detect forgetting to remove the key KY. However, the transponder T is detected by a signal from the communication presence / absence detecting means 19. When the recognizing means 18 recognizes that no communication is being performed with the power supply 21, the power switch 21 is turned off to stop the current supply. Thereby, when it is recognized that there is no communication (that is, the key KY is not forgotten to be removed), the current supply of the immobilizer 1 itself can be automatically stopped, and the life of the battery can be improved. .
[0036]
On the other hand, the transponder T operates on the basis of a radio signal sent from the immobilizer 1 and transmits a signal as a response to the radio signal to the immobilizer 1 as a radio signal. The transponder T is molded in the resin gripping part of the key KY. However, the transponder T may be molded in a resin separate from the key KY and connected to the key KY.
[0037]
Further, as shown in FIG. 2, the transponder T receives the radio signal transmitted from the immobilizer 1, and the antenna 25 for transmitting information generated on the transponder T side to the immobilizer 1, and the modulation / demodulation for modulating the radio signal. Communication unit 26, authentication key generation IC 27 for generating the above-mentioned authentication key, EEPROM 28 which is a nonvolatile storage means for storing information unique to key KY, and capacitor 29 corresponding to a secondary battery Consists mainly of.
[0038]
Next, the operation of the immobilizer with the above configuration will be described.
When the driver inserts the key KY into the key cylinder 23 and then turns it to the operating position (ON position), the main switch 24 is turned ON and the battery 22 is connected to the power supply unit 6. Thereby, VDD20 is output from the power supply part 6, and the immobilizer 1 starts operation | movement. A series of starting control will be described below with reference to the flowchart of FIG.
[0039]
When the immobilizer starts operating, first, the time during which the immobilizer 1 is operating is measured by the time measuring means realized by software (S1). Next, whether or not the engine is operating is confirmed by a signal from the engine control unit 9 (S2). However, since the engine is not started when the key KY is inserted, the start time stored in the EEPROM 5 by the CPU 2 is determined. Data is read (S3).
[0040]
Next, the random number generation means 13 in the CPU 2 generates random number data based on the start time data read in S3 (S4), and adds a password to this to generate transmission data (S5). The transmission data generated here is modulated by the communication unit 3 and transmitted to the transponder T side via the antenna 8 (S6).
[0041]
On the other hand, on the transponder T side, the communication data emitted from the antenna 8 is received by the antenna 25 (S12), and the communication data is demodulated by the communication unit 26. The communication data is encrypted by the authentication key generation IC 27 by using the encryption key of the information unique to the key KY stored in the EEPROM 28, and an authentication key is generated (S13). The authentication key generated in this way is returned to the immobilizer 1 side via the communication unit 26 and the antenna 25 (S14).
[0042]
While the transponder T is generating the authentication key, an authentication code is generated on the immobilizer 1 side (S7). Such an authentication code is obtained by encrypting transmission data by the same encryption processing method used on the transponder T side, and is configured to be generated based on information unique to the key KY stored in the EEPROM 5. .
[0043]
Thereafter, the authentication key sent from the transponder T is received (S8), and comparison authentication between the authentication key and the generated authentication code is performed (S9). As a result, if the authentication key matches the authentication code, an engine start permission signal is transmitted to the engine control unit 9 to start the engine.
[0044]
Thereafter, the engine start is confirmed again (S2), the start time is counted, and the EEPROM 5 is updated using the start time as start time data (S11). As a result of the comparison authentication, if the authentication key and the authentication code do not match, the engine start permission signal is not transmitted, and the process returns to S2 and a series of control is performed from the confirmation of the engine start signal. After the updating of the EEPROM 5 in S11 is completed, a series of start-up control is completed. However, the power switch 21 is not turned off in order to perform control when the engine is stopped as described below.
[0045]
Next, control when the engine is stopped will be described below based on the flowchart of FIG.
First, when the off state detecting means 17 detects that the main switch 24 is in the off state (S100), the timer 7 is activated (S101), and the time when the main switch 24 is off is measured as an initial value. . Thereafter, the presence / absence of communication with the transponder T is detected by the communication presence / absence detection means 18 (S102), and when communication is being performed with the transponder T, a predetermined time after the main switch 24 is turned off. On the other hand, when the communication is not performed, the power switch 21 is turned off and the current supply to the immobilizer 1 is stopped (S108).
[0046]
In S103, when the elapse of a predetermined time is detected, the timer 7 is reset and the buzzer 10 is activated to warn the driver that the key has been forgotten to be removed (S105). Further, the time when the operation of the buzzer 10 is set to the initial value is measured by the timer 7 after reset, and when it is detected that a predetermined time has passed (S106), the buzzer 10 is stopped (S107). Thereafter, the power switch 21 is turned off, and the current supply is stopped (S108). As a result, the immobilizer 1 is put into a resting state, and a series of control at the time of engine stop is completed.
[0047]
The above is the operation in the immobilizer 1 of the present embodiment, but as another embodiment, the control at the time of engine stop may be configured by the control shown in the flowchart of FIG.
That is, when it is detected by the off state detection means 17 that the main switch 24 is in the off state (S200), the presence / absence of communication with the transponder T is detected by the communication presence / absence detection means 18 (S201). When communication is being performed, the buzzer 10 is immediately activated (S202). On the other hand, when communication is not being performed, the power switch 21 is turned off and the current supply to the immobilizer 1 is stopped (S203).
[0048]
Since the operation of the buzzer 10 is performed until communication with the transponder T is stopped by the communication presence / absence detecting means 18 (that is, until the key KY is pulled out from the key cylinder 23), forgetting to remove the key KY can be reliably prevented. At the same time, since the timer 7 can be dispensed with, the apparatus configuration can be simplified. The operation time of the buzzer 10 may be measured by a timer, and the buzzer 10 may be stopped when a predetermined time has elapsed.
[0049]
According to the above two embodiments, since the immobilizer has a mechanism for forgetting to remove the key, the immobilizer alone can prevent forgetting to remove the key, and there is no need to provide a new switch or the like for the key cylinder 23. . Therefore, it can be suitable for a motorcycle or the like that does not have much space near the key cylinder. Furthermore, by preventing forgetting to remove the key, the effectiveness of the immobilizer itself for preventing theft increases, and the antitheft effect can be improved.
[0050]
Although the present embodiment has been described above, the present invention is not limited thereto. For example, other warning means (such as sounding a two-wheeled vehicle horn or voice warning) may be used instead of a buzzer. It may be configured to warn of forgetting to remove a key by blinking or lighting a warning light or an indicator light on a predetermined screen. Further, in the present embodiment, a separate timer is provided to detect the elapse of a predetermined time, but instead of this, it may be configured to detect by a time measuring means realized by software.
[0051]
Furthermore, the control at the time of starting the immobilizer is not limited to that of the present embodiment, and based on the information of the transponder built in the key for the vehicle, is the key used for starting the engine unique to the vehicle? Any other configuration can be applied as long as it can be discriminated and prevent theft of the vehicle. The present invention can be applied to a key portion of a four-wheeled vehicle, an outboard motor, a snow vehicle, etc. in addition to a two-wheeled vehicle.
[0052]
【The invention's effect】
  Claim 1 and claim4According to the invention, the immobilizer is configured to recognize the forgetting to remove the key and warn the driver. Therefore, even in a two-wheeled vehicle, the forgetting to remove the key can be effectively prevented, and the vehicle is prevented from being stolen. If the effect can be further improvedIn both cases, the immobilizer that needs to be supplied with a constant current to detect forgetting to remove the key can be stopped when the communication with the transponder is not detected, thus improving the battery life. it can.
[0053]
  Claim 2 and claim5According to the invention, since the detection of the communication with the transponder and the detected state of the main switch off state recognizes that the key is forgotten to be removed on the condition that the predetermined time has elapsed, the main switch is turned off. Instead of warning immediately, a warning can be given after a predetermined time.
[0054]
  Claim 3 and claim6According to the invention, the warning is stopped when the warning for the driver has passed for a predetermined time, so that the power consumption by the warning can be reduced and the life of the battery can be improved, and noise to the surroundings is required. It can be minimized.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of an immobilizer according to an embodiment of the present invention.
FIG. 2 is a block diagram showing a configuration of a transponder for communicating with an immobilizer according to an embodiment of the present invention.
FIG. 3 is a block diagram showing a configuration of a CPU in the immobilizer according to the embodiment of the present invention.
FIG. 4 is a flowchart showing control at the start of the immobilizer according to the embodiment of the present invention.
FIG. 5 is a flowchart showing control when the immobilizer according to the embodiment of the present invention ends (when the engine is stopped).
FIG. 6 is a flowchart showing control at the end of the immobilizer (when the engine is stopped) according to another embodiment of the present invention.
[Explanation of symbols]
1 ... Immobilizer
2 ... CPU
3 ... Communication Department
4. Communication I / F
5… EEPROM
6 ... Power supply
7 ... Timer
8 ... Antenna
9 ... Engine control unit
10 ... Buzzer
11. Start control unit
12 ... End control unit
13 ... Random number generation means
14: Transmission data generation means
15: Authentication code generation means
16: Authentication means
17: Off state detection means
18 ... Recognition means
19: Communication presence / absence detection means
20 ... VDD
21 ... Power switch
22 ... Battery
23 ... Key cylinder
24 ... Main switch
25 ... Antenna
26. Communication part
27 ... Authentication key generation IC
28… EEPROM
29 ... Capacitor
T ... Transponder
KY ... key

Claims (6)

Wireless communication is performed with a transponder built in a key used to start the engine of the vehicle, and based on the information of the transponder, it is determined whether the key is unique to the vehicle, thereby preventing the vehicle from being stolen. In immobilizer,
Communication presence / absence detecting means for detecting presence / absence of communication of a communication unit that performs wireless communication with the transponder;
An off state detecting means for detecting an off state of the main switch;
When the communication presence / absence detecting means detects communication with the transponder and the off-state detecting means detects that the main switch is turned off, it recognizes that the key has been forgotten to be removed. Recognition means to
Warning means for warning the driver when the recognition means recognizes that the key has been forgotten to be removed;
The immobilizer is characterized in that when the communication presence / absence detecting means does not detect communication with the transponder, the current supply of the immobilizer itself is stopped .   A timer for detecting that a predetermined time has elapsed since the main switch is turned off; and the recognition means detects the presence or absence of communication by the communication presence / absence detection means, and the main switch is turned off by the off-state detection means 2. The immobilizer according to claim 1, wherein in addition to the detection of the above, the immobilizer recognizes that the key has been forgotten to be removed on condition that the predetermined time elapse is detected by the timer.   The immobilizer according to claim 1 or 2, wherein the timer detects that the warning by the warning means elapses for a predetermined time, and the warning is stopped by the detection. Wireless communication is performed with a transponder built in a key used to start the engine of the vehicle, and based on the information of the transponder, it is determined whether the key is unique to the vehicle, thereby preventing the vehicle from being stolen. It is a method to prevent forgetting to remove the key with an immobilizer,
When it is detected that communication with the transponder is detected, and when the main switch is detected to be off, the key is forgotten to be removed and a warning is given to the driver . A method of preventing forgetting to remove a key by an immobilizer, characterized in that the current supply of the immobilizer itself is stopped when communication with the transponder is not detected .   5. The forgetting to remove the key by the immobilizer according to claim 4, wherein the key is forgotten to be removed when there is communication with the transponder and the main switch is turned off for a predetermined time. Prevention method.   6. The method for preventing forgetting to remove a key by an immobilizer according to claim 4, wherein the warning is stopped when a warning for the driver has passed for a predetermined time.

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