JP2981142B2 - Vehicle anti-theft device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle anti-theft device, and more particularly to a vehicle anti-theft device in which an ID code registered in an engine key or the like and an ID code registered in a vehicle satisfy a predetermined relationship. The present invention relates to a vehicle anti-theft device that enables an engine to start under the condition.

[0002]

2. Description of the Related Art While various proposals have been made to prevent theft of vehicles such as automobiles, when an attempt is made to start or run a vehicle using an incorrect key, the vehicle is mechanically or electrically driven. Prohibition of starting and running (immobilize)
There are things that I try to do. For this purpose, an identification code, that is, an ID code is built in the key, and when the key is inserted into the key cylinder to start the vehicle, the ID code built in the key is read, and a reference ID registered in advance in the vehicle is read. The code is collated, and only when the two match, a validity determination signal is generated to enable the engine start.

[0003] In this case, the validity judgment signal is 2 on / off.
If the signal is a value signal, theft may be performed due to mechanical destruction or improper wiring. Therefore, it has been proposed to code the validity determination signal (for example, "Automotive Technology", 1994, See Vol. 48, No. 8, pp. 59-64).

FIG. 8 shows an example of such a conventional transponder type immobilizer. Key 2
Has a built-in memory (not shown) in which a key ID code (for example, 64 bits) is stored in advance, and a transmitter 4 for transmitting the key ID code. The transmitter 4 of the key 2 and the key cylinder 5 are connected by, for example, an induction coil (antenna) 6.

When the key 2 is inserted into the key cylinder 5 and turned to the position where the ignition is turned on, the ignition switch 7 is closed. In response, an immobilizer control hybrid IC (hereinafter, immobilizer HI) in an engine control unit (hereinafter, referred to as ECU) 30 is provided.
The immobilizer CPU 13 built in the C 10 (expressed as C) operates, and power is supplied from the antenna unit 19 to the transmitter 4 via the induction coil (antenna) 6. The antenna unit 19 includes the fuel injection valve 17, the fuel pump 1
8, together with the ignition control unit 20, the battery 21, and the like, are electrically connected to the ECU 30 via a pair of connectors 40 and 50. When power is supplied, the transmitter 4 reads the ID code stored in the key 2 and transmits the ID code to the key cylinder 5 side.

[0006] The received key ID code is amplified in the antenna unit 19, and the key ID code in the immobilizer HIC 10 is
Read by the immobilizer CPU 13 via the / F circuit 12,
It is temporarily stored in an appropriate ID code register 13B. In the EEPROM 14 of the immobilizer HIC 10, a unique reference ID code assigned to each vehicle is registered in advance, and the reference ID code and the read key ID are registered.
The code and the code are compared and collated by the collation function unit 13S of the immobilizer CPU 13. If it is determined that they match or have a predetermined relationship, a validity determination signal is transmitted from the collation function unit 13S to the engine CPU 16 using the determination signal line L3. At the same time, the starter relay is energized and the starter motor (both not shown) starts rotating.

[0007] The ROM 15 of the engine CPU 16 stores an engine control program including at least an engine control algorithm, an input / output control algorithm, and an anti-theft control algorithm.
Various learning data used for engine control are stored. The engine CPU 16 operates according to the engine control program, and determines and confirms the reception of the determination signal based on the anti-theft control algorithm. And
If the determination signal is a normal code signal, the fuel injection valve 17 on the signal port selected by the input / output control algorithm,
For the fuel pump 18, the ignition control unit 20, etc.
Executes unique control based on an engine control algorithm to enable starting and running of the vehicle.

On the other hand, the reference ID code registered in the EEPROM 14 and the key ID transmitted and read from the key 2
If the codes do not match or have no predetermined relationship, the matching function unit 13S does not send the validity determination signal. Therefore, the starting of the vehicle by the engine CPU 16 is prohibited, and the alarm (not shown) is activated by the immobilizer CPU 13 to provide an appropriate alarm and display.

Similarly, even when the validity determination signal transmitted from the collation function unit 13S is not a proper code signal, the starting of the vehicle by the engine CPU 16 is prohibited. In this way, unauthorized starting and running of the engine by an unauthorized key are prevented, and vehicle theft is reliably prevented.

By the way, in the above configuration, the immobilized HI
If a failure (such as a disconnection or short circuit in the circuit wiring) occurs in the C10 itself, there is a problem that a valid judgment signal is not output even though the starting operation is performed by a proper ignition key, and the engine cannot be started and the vehicle cannot be run. . Therefore,
In Japanese Patent Application No. 6-278572 filed by the present applicant, attention is paid to the fact that when the immobilizer HIC 10 fails, its output level is often unstable or uncertain, and the determination signal line L3 is connected to a pull-up resistor. It is fixed at "H" level by R0. Then, when a proper key is used, a predetermined pulse signal (valid determination signal) is output, and when an incorrect key is used, an “L” level (ground or reference) DC signal is output. Like that.

In this way, when an authorized key is used and when an incorrect key is used, the pulse signal and the "L" level DC signal output from the immobilizer HIC 10 are sent to the engine CPU 16 as they are. On the other hand, when the immobilizer HIC10 fails and the output level becomes unstable, the pulled-up "H" level DC signal is input. Accordingly, the engine CPU 16 detects the input signal, prohibits the engine control if the signal is "L" level, and permits the engine control if the signal is a predetermined pulse signal or "H" level. Even in this case, engine control becomes possible.

[0012]

In the prior art described above, the immobilizer HIC 10 is intentionally destroyed by a malicious third party or is detached from the ECU 30, so that the output level of the determination signal line L3 is unstable or not. Even when it is determined, since the "H" level signal pulled up by the pull-up resistor R0 is input to the engine CPU 16, the engine CPU 16 erroneously recognizes this as a failure determination signal, There was a problem that engine control became possible.

An object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a function to enable starting of the engine and the like even if a normal code signal cannot be detected when a failure of the immobilizer HIC 10 itself is detected. It is an object of the present invention to provide a vehicle anti-theft device that is disabled when the immobilizer HIC 10 is intentionally destroyed.

[0014]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a theft determining means for performing a theft determination if an externally input ID code is not a valid ID code; A means for permitting engine control as long as the operation is not performed, a vandalism detecting means for detecting the presence or absence of vandalism for the theft determining means, and a means for inhibiting engine control when the vandalism is detected. There is a feature.

[0015]

According to the above configuration, even if the theft determination is not performed, the engine control is not immediately permitted, and the presence or absence of vandalism against the theft determination means is detected. When the vandalism is recognized, the engine control is prohibited. Therefore, even when the theft determination means cannot perform the theft determination due to the destruction, the engine control is prohibited and the vehicle theft can be more reliably prevented.

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 3 is a block diagram of a main part of an ECU having a vehicle anti-theft function according to a first embodiment of the present invention, and FIG. 4 is a diagram showing a circuit board configuration of a main part of the immobilizer HIC10. The same reference numerals indicate the same or equivalent parts.

In FIG. 4, the substrate 1 of the immobilizer HIC10 is shown.
When the signal lines among the various signal lines wired above are disconnected, the output level of the judgment signal output terminal S1 of the immobilizer CPU 13 becomes unstable and uncertain, and the pull-up resistor R
0, a signal line to which an "H" level signal is supplied to the determination signal line L3, in other words, if the malicious third party intentionally disconnects, the immobilizer HIC1
In the vicinity of a signal line from which a failure determination signal similar to that at the time of a failure of 0 can be output, a dummy line Ld for destruction detection is wired.

More specifically, a power supply line L1 connecting at least the power supply pin P1 of the immobilizer HIC10 and a power supply terminal VDD of the immobilizer CPU 13, etc., and a ground pin P2
A ground line L2 connecting the IMOBI CPU 13 and the ground terminal Vcc, a determination signal line L3 connecting the determination signal output pin P3 of the IMOBI HIC10 to the determination signal output terminal S1 of the IMOBI CPU 13, and a clock signal are supplied to the IMOBI CPU 13. In the vicinity of the reference clock line L4 to which the quartz oscillator 131 is connected, a dummy line Ld for destruction detection is wired along each line.

As shown, one end of the dummy line Ld is connected to the power supply line L1 via a pull-up resistor R1. Then, from one end, the power supply line L1
After being routed along the determination signal line L3, the through hole 51 intersects with the determination signal line L3.
After returning to the front surface of the substrate via the back surface of the substrate by 52 and further routed along the determination signal line L3, the reference clock line L4, and the ground line L2, the other end is connected to the dummy line connection pin P3 of the immobilizer HIC10. It is connected. Dummy line connection pin P3 and engine C
The signal input terminal of the PU 16 is connected to a dummy signal line L5, and the dummy signal line L5 is connected to a ground potential source via a pull-down resistor R2.

In such a configuration, when a proper engine key is used and when an incorrect engine key is used, a predetermined pulse signal (valid determination signal) and " Since an L ″ level DC signal (theft determination signal) is output, the engine CP
U16 can make a correct determination by detecting the signal.

The dummy line signal input to the engine CPU 16 from the dummy signal line L5 is a pull-up resistor R0 unless the dummy line Ld is disconnected.
In order for the pull-down resistor R1 to function as a voltage dividing resistor, a predetermined level (e.g., 6 V) is set based on the resistance value of each of the resistors R1 and R2 and the power supply voltage value (e.g.
v) DC voltage.

On the other hand, if a malicious third party attempts to cut the signal lines L1 to L4 by scratching the substrate surface of the immobilizer HIC 10, the dummy line Ld will be cut at the same time. As a result, since the pull-up resistor R1 does not function at all, the dummy line signal is fixed at the "L" level by the pull-down resistor R2. Similarly, when the entire immobilizer HIC 10 is removed, the dummy line signal is fixed to the ground potential by the pull-down resistor R2.

The engine CPU 16 determines that the vehicle is stolen if the dummy line signal is at "L" level, and prohibits engine control even if a failure determination signal is detected as a determination signal.

In order to make the dummy line Ld easier to be cut than the other signal lines, the dummy line Ld is made thinner or narrower than the other signal lines L1 to L4, thereby reducing the signal width. It is desirable that the dummy line Ld is always cut when an action such as cutting the line is performed.

FIG. 1 is a block diagram showing the function of this embodiment, and FIG. 5 is a flowchart showing the operation thereof.
The same reference numerals as those described above denote the same or equivalent parts.

In FIG. 1, the judgment signal generating means 61
This is one of the functions of the immobilizer CPU 13. When the ID code input from the outside is a valid ID code, a validity determination signal is output. When the ID code is invalid, a theft determination signal is output. Output to the top. The failure signal generating means 62 is a function of the pull-up resistor R0, and generates a failure determination signal on the determination signal line when the signal level of the determination signal becomes indefinite.

The disconnection detecting means 64 includes the engine CPU
16 is a function of detecting the disconnection of the dummy line Ld. The engine control means 63 is provided with the engine CPU 16.
The engine control is permitted in response to the validity determination signal and the failure determination signal, and the engine control is prohibited in response to the theft determination signal. Prohibits engine control regardless of the signal.

In such a configuration, in step S1, the presence or absence of the input of the ID code is determined by the determination signal generating means 61, and if the ID code is detected, the process proceeds to step S1.
In step 2, the data is compared with a reference ID code stored in advance. In step S3, a code signal (regular determination signal) as shown in FIG. 7A is output if the two match, according to the comparison and collation result.
An "L" level DC signal (theft determination signal) as shown in (b) is output. On the other hand, when the output of the immobilizer CPU13 is uncertain, the failure determination signal generating means 62, "H" level of the DC signal as shown in FIG. 7 (c) (fault signal) is generated.

In step S5, the engine control means 63
The type of the determination signal is determined by the following. If the signal is a normal determination signal, the process proceeds to step S6 to permit the engine control, and if the signal is a theft determination signal, the process proceeds to step S7 to inhibit the engine control. If the signal is a failure determination signal, the disconnection detecting means 64 detects a dummy line signal in step S8, and determines in step S9 whether the dummy line Ld is disconnected. Here, if it is determined that the cutting has been performed, the process proceeds to step S7, in which the engine control is prohibited. If it is determined that the cutting has not been performed, the process proceeds to step S6, in which the engine control is permitted. You.

According to this embodiment, even if the failure determination signal is detected, the engine control is not immediately permitted, and it is determined whether or not the dummy line is disconnected. If the dummy line is not cut, the engine control is permitted, while if the dummy line is cut, the engine control is prohibited. Therefore, if the generation of the failure determination signal is caused by disconnection of the signal lines L1 to L2, as in the case where the immobilizer CPU 13 is intentionally destroyed,
It is determined that the wrongdoing has been performed, and the engine control is prohibited.

FIG. 2 is a block diagram showing the function of the second embodiment of the present invention, and FIG. 6 is a flowchart showing the operation thereof. The same reference numerals as those described above denote the same or equivalent parts (processes). ing.

In the first embodiment, the immobilizer HIC1
0 is detected by the dummy line Ld.
Was performed on the basis of whether or not
The IC 10 is housed in the ECU 30, and the ECU 30 is also housed under a seat of a vehicle, in an engine room, or the like.
Therefore, in order to destroy the immobilizer HIC10, EC
It is necessary to remove the U30 wiring (usually performed by a pluggable connector or the like) and the fixing member and take it out of the vehicle, open the case of the ECU 30, break the immobilizer HIC 10, and then attach it again to the vehicle. Become.

Here, the engine CPU 16 of the ECU 30
Contains a volatile memory 11 for storing the learning data. The volatile memory 11 is backed up by appropriate means such as a capacitor so that data is not lost even if the battery voltage is momentarily interrupted.
If the wiring of U30 is removed and the power supply from the battery is stopped, the capacitor is discharged in a short time and data is lost.

Therefore, in the second embodiment, the immobilized HI
In order to destroy C10, it is necessary to disconnect the ECU 30 from the battery line, and paying attention to the fact that the data in the volatile memory 11 will be lost if the ECU 30 is disconnected from the battery line. Whether or not the immobilizer HIC10 has been destroyed is detected by the history detecting means 65, and based on the detection result.

In such a configuration, steps S1 to S1
In S5, the I signal by the determination signal
Collation of the D code and identification of the determination signal by the engine control means 63 are performed. Here, when the normal judgment signal or the theft judgment signal is detected, the permission and the prohibition of the engine control are respectively performed similarly to the case of the first embodiment.

On the other hand, when a failure determination signal is detected, in step S8a, the history detection means 65 detects data in the volatile memory 11, and in step S9a, the presence or absence of data is determined. Here, if it is determined that the data is lost, the process proceeds to step S7, and the engine control is prohibited. If it is determined that the data is not lost, the process proceeds to step S6, and the engine control is performed. Allowed.

According to this embodiment, even if the failure determination signal is detected, the engine control permission signal is not immediately output,
The presence or absence of data in the volatile memory is determined. If the data is not lost, the engine control is permitted, while if the data is lost, the engine control is prohibited. Therefore, to destroy the immobilizer HIC10, E
If the occurrence of the failure determination signal is caused by disconnection of the ECU 30 from the battery line, as in the case where the CU 30 is disconnected from the battery line, it is determined that an illegal act has been performed and engine control is prohibited. You.

[0038]

As described above, according to the present invention, the following effects can be achieved. (1) According to the first embodiment of the present invention, even if the failure determination signal is detected, the engine control permission signal is not immediately output, and it is determined whether or not the dummy line is disconnected. If the dummy line is not cut, the engine control is permitted, while if the dummy line is cut, the engine control is prohibited. Therefore, if the occurrence of the failure determination signal is caused by the disconnection of the signal line, such as when the device is intentionally destroyed, it is determined that an illegal act has been performed, and the engine control is prohibited. Vehicle theft is prevented. (2) According to the second embodiment of the present invention, even if the failure determination signal is detected, the engine control permission signal is not immediately output, and the presence or absence of data in the volatile memory is determined. And
If data is not lost, engine control is permitted, while if data is lost, engine control is prohibited. Therefore, if the occurrence of the failure determination signal is caused by disconnection of the device from the battery line, as in the case where the vehicle theft prevention device is destroyed,
It is determined that the wrongdoing has been performed, and the engine control is prohibited, thereby preventing the vehicle from being stolen.

[Brief description of the drawings]

FIG. 1 is a functional block diagram of a main part of a first embodiment of the present invention.

FIG. 2 is a functional block diagram of a main part of a second embodiment of the present invention.

FIG. 3 is a block diagram showing a specific configuration of the first embodiment.

FIG. 4 is a block diagram showing a configuration of a main part of the first embodiment.

FIG. 5 is a flowchart showing the operation of the first embodiment.

FIG. 6 is a flowchart showing the operation of the second embodiment.

FIG. 7 is a diagram illustrating an example of a signal waveform of each determination signal.

FIG. 8 is a block diagram of a conventional transponder type immobilizer.

[Explanation of symbols]

2 ... key, 4 ... transmitter, 5 ... key cylinder, 6 ... induction coil (antenna), 7 ... ignition switch, 10
... Imobi HIC, 13 ... Imobi CPU, 14 ... EEPR
OM, 16: engine ECU, 17: fuel injection valve, 18
... Fuel pump, 19 ... Antenna unit, 30 ... EC
U, 40, 50 ... connector

Continuation of the front page (56) References JP-A-6-156191 (JP, A) JP-A-63-226471 (JP, A) JP-A-4-297354 (JP, A) JP-A-5-229401 (JP) JP-A-4-278864 (JP, A) JP-A-61-55785 (JP, U) JP-A-3-86872 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB Name) B60R 25/04 602

Claims (13)

(57) [Claims] An ID code entered from outside is valid.
If the ID code is a valid ID code,
If not, theft determination means for outputting a theft determination signal respectively , and detecting the validity determination signal to permit engine control, and
Detects the difficulty determination signal and prohibits engine control.
If neither the judgment signal nor the theft judgment signal can be detected
Engine control means for permitting engine control, vandalism detection means for detecting the presence or absence of vandalism with respect to the theft determination means, and detection of both the validity determination signal and the theft determination signal.
Prohibiting means for prohibiting engine control when the vandalism is detected without flaws . 2. A dummy line is routed in the vicinity of a signal line constituting the theft judging means, and the vandalism detecting means detects breakage of the dummy line and performs vandalism detection. The vehicle anti-theft device according to claim 1, wherein: 3. The vehicle antitheft device according to claim 1, wherein the vandalism detection means detects the history of disconnection of the vehicle antitheft device from the battery line and detects the vandalism. 4. When the ID code inputted from the outside is a valid ID code, a validity judgment signal is sent to a valid ID code.
A determination signal generating means for outputting a theft determination signal on the determination signal line when the code is not a D code; and a failure signal generating means for generating a failure determination signal on the determination signal line when the signal level of the determination signal becomes uncertain. A dummy line routed in the vicinity of a signal line of which the signal level of the determination signal becomes indeterminate when disconnected among the signal lines constituting the determination signal generating means; and a disconnection detecting the disconnection of the dummy line. a detection means, wherein to allow the engine control in response to the correctness determination signal and the fault signal, while prohibiting the engine control in response to the theft determination signal, the cutting of the dummy line is detected, the failure determination An anti-theft device for a vehicle, comprising: engine control means for prohibiting engine control regardless of a signal. 5. The signal line of the determination signal generating means in which the dummy line is routed to the vicinity is at least one of a power supply line, a ground line, a determination signal line, and a reference clock line. Item 5. The vehicle antitheft device according to Item 4. 6. The vehicle antitheft device according to claim 4, wherein the failure signal generating means is means for connecting a determination signal line to a fixed potential via a resistance means. 7. The disconnection detecting device further comprises: means for connecting one end of the dummy line to a first fixed potential; and means for connecting the other end of the dummy line to a second fixed potential via a resistance means. 7. The vehicle antitheft device according to claim 4, wherein the means detects disconnection based on a signal level at the other end of the dummy line. 8. The vehicle anti-theft device according to claim 7, wherein one end of the dummy line is connected to a first fixed potential via a resistance means. 9. The vehicle anti-theft device according to claim 4, wherein the dummy line is more easily cut by an external force than other signal lines. 10. Judgment for outputting a judging signal when the ID code inputted from outside is a valid ID code, and outputting a theft judging signal when the ID code is not a valid ID code. Signal generation means, failure signal generation means for generating a failure determination signal on the determination signal line when the signal level of the determination signal becomes uncertain, and permitting engine control in response to the validity determination signal and the failure determination signal. And an engine control means for prohibiting engine control in response to a theft determination signal, wherein the vehicle anti-theft device is supplied with power via a battery line. The engine control means further includes a history detection means for detecting the vehicle antitheft device by the history detection means. When disconnecting history from reline is detected, the vehicle theft prevention device and inhibits the engine control regardless of the fault signal. 11. A volatile storage unit for storing engine control data, and a unit for backing up the volatile storage unit with a battery, wherein the history detection unit refers to storage contents of the volatile storage unit. 11. The vehicle anti-theft device according to claim 10, wherein if the storage content is lost, the presence of a disconnection history is detected. 12. The vehicle antitheft device according to claim 4, wherein the validity determination signal is a pulse signal having a predetermined cycle and a predetermined duty ratio. 13. The system according to claim 4, wherein the failure determination signal and the theft determination signal are DC signals of a first level and a second level different from the first level, respectively.
3. The vehicle theft prevention device according to any one of 2.