JPH08291657A - Door lock controller for car - Google Patents

Abstract

PURPOSE: To promote security for ID code in a door lock controller by means of a remote controller. CONSTITUTION: A transmitter is incorporated in to a car key, and the transmitter transmits ID code in response to operation of an operating switch 1. The transmission is made on the basis of the ID code stored in a nonvolatile memory 6, and increment of a count code section of the ID code is made in the case of transmission. A receiver is installed in a car, ID code from the transmitter is received, and when the ID code is bigger than ID code stored in the nonvolatile memory 25, a door is locked or unlocked, and then, the ID code of the nonvolatile memory 25 is rewritten to the received ID code. These controls are made with MPU 3 in the transmitter side and are made with MPU 20 in the receiver side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle door lock control device which receives an ID code from a transmitter and performs door lock control.

[0002]

2. Description of the Related Art Conventionally, in a vehicle door lock control device for controlling a vehicle door lock using a remote control device, an operator having a vehicle key having a transmitter operates a transmission switch by approaching the vehicle. Then I from the transmitter
The D code is transmitted and the I code is sent to the receiver installed in the vehicle.
When the D code is received and the ID code matches the prestored ID code, the vehicle door is locked or unlocked.

[0003]

However, the ID code transmitted may be intercepted by a third party in the receivable range. For example, when the communication medium is infrared rays, it is possible to read the transmission ID code by using a copying machine for infrared transmission code. If this reading is successful, a third party can unlock the door using the ID code, which causes a security problem.

The present invention has been made in view of the above problems, and an object thereof is to improve the security function for the ID code.

[0005]

In order to achieve the above-mentioned object, the present invention provides a transmitter for transmitting an ID code and a transmitter provided on a vehicle side for transmitting the ID code. In a vehicle door lock control device including a receiver that performs door lock control based on an ID code,
The ID code includes a code-invariant fixed code part and a code-variable variable code part.
Code changing means (102) is provided for changing the variable code section according to a predetermined rule every time the D code is transmitted, while the fixed code section received matches the predetermined one in the receiver. First determination means (1
05), a second judging means (106) for judging whether or not the received variable code portion is changed according to the predetermined rule, and judgments in the first judging means and the second judging means. Is provided, the door lock control means (107) for controlling the door lock is provided.

According to the second aspect of the invention, the predetermined rule in the code changing means (102) increments the value of the variable code section every time an ID code is transmitted, and the receiver is In the determination in the second determining means (106), the storage means (25) stores the received variable code part, and the value of the variable code part received this time is stored in the storage means (25). It is determined that the value is larger than the stored value of the variable code portion at the time of the previous reception.

In the invention according to the third aspect, the predetermined rule in the code changing means is to decrement the value of the variable code portion every time the ID code is transmitted, and the receiver receives the received signal. In the determination by the second determination means, the value of the variable code portion received this time is the value of the variable code portion at the time of the previous reception stored in the storage means. Is smaller than the above.

In the invention according to claim 4, the second judging means is further configured such that the value of the variable code part received this time is higher than the value of the variable code part stored in the storage means at the time of the previous reception. It is set so as to make a negative determination when it is larger than a predetermined increment amount. In the invention according to claim 5, the value of the variable code part received this time is further decremented by a predetermined value than the value of the variable code part stored in the storage means at the time of the previous reception. It is set to make a negative judgment when it is smaller than the amount.

In the invention according to claim 6, the first judging means (105) and the second judging means (10)
When any of 6) makes a negative determination, an alarm means (110) for issuing an alarm when a plurality of the ID codes received before and after is identical to each other is further provided on the vehicle side. The reference numerals in parentheses of the above-mentioned means indicate the correspondence with the concrete means described in the embodiments described later.

[0010]

According to the invention described in claim 1, I
Since the variable code part is changed according to a predetermined rule every time the D code is transmitted, even if a third party plagiarizes the ID code and then transmits it, the code variable code part has a predetermined rule. Since it has not been changed, the judgment on the receiving side becomes negative and the door lock is not controlled. Thereby, the security function for the ID code can be improved.

According to the invention described in claims 2 to 3, the value of the variable code portion can be easily changed by incrementing or decrementing each transmission, and the determination on the receiving side can be made at the time of the previous reception. This can be done simply by comparing the magnitudes of the variable code parts of. According to the inventions of claims 4 to 5, when the value of the variable code portion suddenly changes beyond a predetermined increment amount or decrement amount, the determination on the receiving side becomes negative and the door lock control is performed. It will not be done.
Thereby, for example, even if a stolen person uses a variable code part of a stolen ID code by setting a full bit or resetting the variable code part to zero, the door lock is not released.

According to the sixth aspect of the present invention, when the same ID code is received further before and after in a state where both the first judging means and the second judging means make negative judgments. A warning is given that the ID code has been stolen, and theft on the vehicle is prevented.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIG. 1 shows the configuration of a transmitter and a receiver of a door lock control device using infrared rays as a medium.

The vehicle key has a transmitter built therein, and when the operation switch 1 is operated, the light emitting diode (infrared LED) 2 is blinked to transmit an ID code for locking or unlocking the door. . This ID code is composed of a fixed code part whose code does not change and a variable code part (count code part) which is changed every transmission according to a predetermined rule described later. If the number of bits of the variable code section is sufficiently secured (for example, 20 bits), the variable code section will not overflow due to the increment described later in normal device use.

For transmitting the ID code, the transmitter has an MPU 3 as shown in FIG. This MPU3
Is operating by receiving a voltage supply from a battery 4 built in a vehicle key, reads an ID code stored in the nonvolatile memory 6 when the operation switch 1 is operated, and drives the drive circuit 5 according to the ID code. To drive the light emitting diode 2 to blink.

The vehicle-side receiver receives the ID code from the transmitter and locks or unlocks the door.
Therefore, the infrared light sent from the light emitting diode 2 of the transmitter is received by the light receiving diode (PIN photodiode) 23.
The light is received by and is demodulated by the demodulation circuit 24 and the ID code is M
Input to PU20. The MPU 20 has an in-vehicle battery 21.
It is constantly operated by receiving a constant voltage supply from the constant voltage circuit 22 and compares the ID code input via the demodulation circuit 24 with the ID code stored in the non-volatile memory 25 in the procedure described later. Then, according to the comparison result, an actuator (not shown) is driven to lock or unlock the door.

The processing procedure of the transmitter MPU3 and the receiver MP
The processing procedure of U20 will be described together with the flowchart of FIG. In the figure, in step 101, the transmission switch 1
When is turned on, the MPU 3 increments (adds 1 bit) the value of the counter code portion of the ID code stored in the non-volatile memory 6 and rewrites it (step 10
2) Then, in the following step 103, the rewritten ID code is transmitted.

The transmitted ID code is the light receiving diode 2
3 is received and demodulated by the demodulation circuit 24. MPU20
Inputs the demodulated ID code (step 104),
In step 105, it is determined whether or not the fixed code part of the ID code matches that stored in the nonvolatile memory 25 in advance. If there is a match, follow step 1
At 06, the counter code part (input code) of the ID code received this time is compared with that stored in the nonvolatile memory 25 at the time of the previous reception (storage code). Then, only when the input code> the memory code, step 107
In step 108, the stored code is rewritten to the input code while the door lock / unlock control is performed.

In this way, the I emitted from the transmitter
The counter code part of the D code is incremented and changed every transmission, and the counter code part of the ID code stored in the receiver is also changed in a follow-up manner. Therefore, even if a third party copies the ID code transmitted from the transmitter and then transmits the ID code, the magnitude relationship in step 106 is not established and door opening / closing control is not erroneously performed.

(Second Embodiment) FIG. 3 shows the configuration of a receiver according to the second embodiment of the present invention. An alarm control circuit 26 that operates by receiving the output of the MPU 20 is provided. The alarm control circuit 26 has a headlight and a buzzer (not shown).
Is connected, and the headlight and the buzzer are driven to blink when the alarm output from the MPU 20 is received.

FIG. 4 shows a processing procedure of the MPU 20 in this case. The differences from the first embodiment are steps 109 and 1
That is, 10 is added. That is, step 1
If the check results in both 05 and step 106 are negative, it is checked in step 109 whether the received ID codes are the same code consecutively. As a result, if the codes are the same, it is determined that a third party intentionally opens the door, and in the subsequent step 110, an output is issued to the alarm control circuit 26 to cause the headlight and the buzzer to blink. . This prevents theft and the like on the vehicle.

(Other Embodiments) In each of the above embodiments, the count code portion of the ID code is incremented by a predetermined amount each time it is transmitted, so that the value does not increase sharply. Therefore, the value of the count code part of the received ID code is the nonvolatile memory 2 of the receiver.
If the ID code is ignored when it is larger than the value of the count code portion stored in 5 by a predetermined increment amount, the door lock will not be released even if it is used by a thief. No, the security is further improved.

Further, in each of the above-mentioned embodiments, the count code portion of the ID code is incremented for each transmission, but instead of this, the count code portion is decremented for each transmission, and the value of the received count code portion is set to the value of the receiver. You may confirm that it is smaller than the value of the count code part stored in the non-volatile memory. Then, in this case, if the received count code portion is smaller than the value obtained by subtracting a predetermined decrement amount from the value of the count code portion stored in the nonvolatile memory of the receiver, this ID code is ignored. By doing so, security can be improved in the same manner as described above.

In each of the above-described embodiments, if a check code portion corresponding to these values is further added to the fixed code portion and the count code portion of the ID code, I is added when the count code portion is incremented or decremented.
Since a plurality of bits of the D code change, reliability of ID code reception is improved. The ID code format does not require the fixed code part, the count code part, the check code part, etc. to be arranged in this order, and the order of each bit can be arbitrarily changed or rotated by a predetermined method. Moreover, the confidentiality of the communication of the ID code can be secured by adopting means such as scrambling at the time of transmission.

Each step in the flow charts of the above embodiments may be realized by a hard logic structure as a function executing means.

[Brief description of drawings]

FIG. 1 is a block circuit diagram showing configurations of a transmitter and a receiver of a door lock control device according to a first embodiment of the present invention.

FIG. 2 is a flowchart showing a processing procedure of the MPU according to the first embodiment of the present invention.

FIG. 3 is a block circuit diagram showing a configuration of a receiver of the door lock control device according to the second exemplary embodiment of the present invention.

FIG. 4 is a flowchart showing a processing procedure of the MPU according to the second embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Operation switch, 2 ... Light emitting diode, 3 ... Transmitter side MPU, 6 ... Transmitter side non-volatile memory, 20 ... Receiver side MPU, 23 ... Light receiving diode, 24 ... Demodulation circuit, 25
... Receiver side non-volatile memory, 26 ... Alarm control circuit.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display area E05B 65/20 E05B 65/20 H04Q 9/00 301 H04Q 9/00 301B

Claims (6)

[Claims] 1. A vehicle door lock control device comprising: a transmitter that transmits an ID code; and a receiver that is provided on the vehicle side and performs door lock control based on the ID code transmitted from the transmitter. The ID code is composed of a code-invariant fixed code section and a code-variable variable code section, and the transmitter is provided with code changing means for changing the variable code section according to a predetermined rule each time the ID code is transmitted, On the other hand, in the receiver, the first judging means for judging whether or not the received fixed code part matches a predetermined one, and the received variable code part is changed according to the predetermined rule. Second determination means for determining whether or not the door lock is performed, and a door lock for controlling the door lock when the determinations by the first determination means and the second determination means are both positive Vehicle door lock control device being characterized in that provided a control means. 2. The predetermined rule in the code changing means increments the value of the variable code section each time an ID code is transmitted, and the receiver stores the received variable code section. Having means and second
The determination by the determination means is that the value of the variable code portion received this time is larger than the value of the variable code portion at the time of previous reception stored in the storage means. The vehicle door lock control device according to claim 1. 3. The predetermined rule in the code changing means is to decrement the value of the variable code section each time an ID code is transmitted, and the receiver stores the received variable code section. And the second determining means determines that the value of the variable code part received this time is smaller than the value of the variable code part at the previous reception stored in the storage means. The vehicle door lock control device according to claim 1, wherein the door lock control device is a vehicle door lock control device. 4. The second determination means is further configured such that the value of the variable code portion received this time is larger than the value of the variable code portion stored in the storage means at the time of the previous reception by a predetermined increment amount. The vehicle door lock control device according to claim 2, wherein the door lock control device is set to make a negative determination in some cases. 5. The second determining means is further configured such that the value of the variable code part received this time is smaller than the value of the variable code part stored in the storage means at the time of the previous reception by a predetermined decrement amount. The vehicle door lock control device according to claim 3, wherein the door lock control device is set to make a negative determination in some cases. 6. An alarm is issued when a plurality of the ID codes received before and after are identical with each other at the stage where both the first judging means and the second judging means make a negative judgment. The vehicle door lock control device according to any one of claims 1 to 5, further comprising alarm means for emitting a warning on the vehicle side.