JP3110964B2 - Signal collation method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a signal collating method, and more particularly to a signal collating method suitable for use in a remote control device of a vehicle locking device.

[0002]

2. Description of the Related Art It is generally known that a door lock device provided in a vehicle is remotely locked / unlocked by a radio signal transmitted from a transmission device. In such a device, when a radio signal is copied by another person using a copy device, the door lock device is easily unlocked by the copied signal.

In order to prevent this, a method of changing the radio signal emitted from the transmission device every transmission so that the copy signal cannot be unlocked is disclosed in, for example, Japanese Patent Application Laid-Open No. 1-278671. It has been disclosed. The structure is such that when transmitting a wireless signal (numerical code), a predetermined number is added (or subtracted) to the previously transmitted number and transmitted, and the receiving device stores the previously received wireless signal (numeric code). If the radio signal received this time is larger (or smaller) than the stored signal, unlocking is possible.

[0004]

In order to perform the addition / subtraction process on the previous code, it is necessary to provide a storage device for storing the code in the transmission device. If an E ² PROM is used as this storage device, for example, the cost is high and the size is increased, so that the storage device is generally constituted by a RAM or a counter. In this case, if the number of digits of the numerical code of the radio signal is, for example, 4 decimal digits, the code will increase or decrease between 0001 and 9999. And the initial value 00
Returning to 00, the magnitude comparison cannot be performed. Similarly, when the transmitting device is reset by replacing the battery or the like, the magnitude comparison cannot be performed. That is, for example, the previous code is 999
In the case of 9, even if the variable code of 0000 is received, it cannot be unlocked, and the subsequent maintenance becomes troublesome.

Therefore, in order to avoid such a problem, conventionally, it is necessary to increase the number of digits of the variable code.
In order to secure such a storage capacity, the size and cost of the transmission device must be increased with the increase in the size of the storage device. Also in this case, the problem that the code cannot be identified at the time of resetting the transmission device or the like is not solved. Similar problems always occur when it is necessary to confirm whether or not a received signal is a legitimate signal, such as not only a vehicle door lock device but also a normal building door lock device.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and a main object of the present invention is to increase the size of a signal transmitting / receiving apparatus using a variable code consisting of numerical values as an identification code. Another object of the present invention is to provide a signal collation method that can reliably identify only a legitimate transmission signal without increasing the cost and that can easily perform maintenance when an error occurs.

[0007]

According to the present invention, the above objects include a fixed code that is set in advance and a variable code that is changed by adding a predetermined change to a previously generated code each time it is transmitted. Transmits the signal from the transmitting device and sends it to the vehicle
Provided on the vehicle side for use in the remote control device of the lock device
The fixed code included in the signal received this time and received this time matches the preset fixed code, and the variable code included in the signal received this time is identified as the last valid code. If a predetermined change has been made to the changed variable code, the matching signal is output and the variable code is output .
In a signal collation method for controlling locking / unlocking of a locking device and storing the variable code received this time as a reference variable code to be used next time in the receiving device, the variable code is
The predetermined change has not been made to the reference variable code
If the ignition key switch of the vehicle is
After performing 0N / 0FF the number of times,
Receiving the signal from the communication device, and fixing the fixed signal included in the signal.
If the code matches the legitimate fixed code, the signal
The signal collating method is characterized in that the variable code included in the above is stored in the receiving device as a reference variable code to be used next time. In particular, before
It is preferable that the predetermined change is a change in which the variable code included in the signal received this time is within a predetermined count number with respect to the reference variable code stored in the receiving device.

[0008]

As described above, even if the variable code cannot be identified for some reason between the transmitting device and the receiving device in the remote control device of the vehicle locking device , the ignition key switch of the vehicle is operated a predetermined number of times. 0N / 0FF, after receiving a signal from the transmitting device within a predetermined time, if the fixed code included in the signal matches a predetermined regular fixed code, a variable code included in the received signal is used. Is determined to be a legitimate variable code, it is possible to confirm that the owner of the transmitting device is the legitimate owner, so that unlocking by copying after the occurrence of the error can be reliably prevented. Furthermore, if the variable code included in the signal and the previous variable code (reference variable code) stored in the receiving device are not the magnitude of the numerical value itself, but the difference in the count number changes within a predetermined range. If the variable code is regarded as a legitimate code, even if the variable code overflows and is reset to the initial value, the loop operates normally and the occurrence of the error itself is reduced.

[0009]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a preferred embodiment of the present invention. FIG. 1 shows a portable transmission device 1 and a vehicle-side reception device in a vehicle door lock device having a so-called keyless entry system for locking / unlocking a vehicle door by operating a transmission device from the outside to which the present invention is applied. Device 2
FIG. 2 is a block diagram showing a configuration of a main part of FIG. The transmission device 1 transmits a signal composed of a fixed code and a variable code generated by the internal signal generation circuit 3 to the outside as an infrared signal via the transmission circuit 4. Here, the fixed code is a code unique to the transmission device 1 and is stored in the ROM 5. The variable code is a 4-digit decimal number code that is incremented by one each time the transmission switch 7 is pressed. For example, the previously generated variable code is stored in the RAM 6, and when the transmission switch 7 is pressed, 1 is added to this code. The sum is transmitted to the outside together with the fixed code via the transmission circuit 4, and the variable code with the 1 added is stored in the RAM 6. Note that reference numeral 8 denotes a power supply (battery) of the transmission device 1.

On the other hand, the receiving device 2 has a receiving circuit 11 for receiving the above-mentioned infrared signal and converting it into an electric signal, and a control unit 12. The control unit 12 converts the fixed code of the received signal into E ² P
E ² PR a variable code of the received signal with comparison against the fixed code of the prestored normal to ROM13
The reference variable code previously stored in the OM 13 is compared and collated as described below, and according to the result, the door lock device 1
The variable code received this time is stored in the E ² PROM 13 as a reference variable code at the same time that the drive signal is output to the drive signal 4.

Next, a signal collating procedure in this embodiment will be described with reference to FIG. First, when an infrared signal is received by the receiving apparatus 2 (step 1), the signal is converted into an electric signal, and the fixed code is compared with a regular fixed code stored in advance in the E ² PROM 13 for comparison. If it is determined that the fixed code is a legitimate code, the process proceeds to step 3 where the variable code in the signal is compared with the reference variable code previously received and confirmed to be a legitimate code. If the fixed code of the received signal matches the regular fixed code, and the difference between the count numbers of the variable code of the signal received this time and the reference variable code is a predetermined relationship according to a comparison method described later, the door lock is performed in step 4. A match signal (drive signal) is output to the device 14 and the variable code received this time in step 5 is stored in the E ² PROM 1
3 is stored as a reference variable code. If the difference between the count numbers of the variable code of the signal received this time and the reference variable code does not have a predetermined relationship in step 3,
Steps 31 to 3 of the update subroutine described later
Execute 7.

Here, the above-mentioned variable code is transmitted to the receiving device 2
An example of a condition for determining a legitimate code will be described. First, the variable code is a 4-digit decimal number code having an initial value of 0000 and an upper limit of 9999, that is, 000.
It is an arbitrary number from 0 to 9999. This number is 99
When 1 is added to 99, it is reset to 0000. That is, for example, if 1 is added to the number 9998 four times, 0002
Becomes This may be such that the RAM 6 can store only the last four digits of the number, or the counter may be of four digits. First, it is determined whether or not the variable code A included in the signal received this time is larger than the variable code (reference variable code) B included in the signal received last time. For example, as 256, if 1 ≦ AB ≦ 256 (1), the variable code A is determined to be a normal variable code.

If the variable code A is smaller than the reference variable code B, the variable code is obtained as follows: −9999 ≦ AB ≦ −9999 + 255, ie, 9999 ≧ BA−9744 (2) A is determined to be a normal variable code. Needless to say, if the variable code A is a normal variable code, the variable code A is not equal to the reference variable code B. In this case, the variable code A is not determined to be a normal variable code.

More specifically, for example, the reference variable code B
Is 0100, if the variable code A included in the signal received this time is a code in the range of 0101 to 0356, it is determined to be a normal variable code. That is, when the variable code A is 0357 or more (0357 to 9999), A
Since −B is between 257 and 9899, the variable code A is not determined to be a normal variable code according to the expression (1), and the variable code A is 0100 or less (00
00 to 0100), and since B−A is between 0 and 100, the variable code A is not determined to be a normal variable code by equation (2).

For example, the reference variable code B is 9744
If the value is in the range of ~ 9999, for example, the reference variable code B
Is 9900, the variable code A included in the signal received this time is in the range of 9901 to 9999, or 0000 to 9999.
If the code is in 0156, it is determined to be a regular variable code. That is, when the variable code A is 9901 to 9999, AB becomes 256 or less in all cases (1)
The variable code A is determined as a regular variable code by the equation.
Further, when the variable code A is 0157 to 9900, since BA is between 0 and 9743, the variable code A is not determined to be a normal variable code by the equation (2).

If the above relationship is expressed by a formula that can be generally processed, the variable code is a numerical code that returns to the initial value a when the variable code exceeds the upper limit N, and the variable code A included in the signal received this time is the reference variable code. When the variable code A is larger than B, if 1 ≦ AB ≦ S, the variable code A is determined to be a normal variable code. When the variable code A is smaller than the reference variable code B, N- If a ≧ BA ≧ N−S−a + 1, the variable code A is determined to be a normal variable code. In this embodiment, a = 0, N = 9999, S = 256
It is. The set value of the permissible change count S is arbitrary, but if it is too small, the condition may be lost if the transmission switch is erroneously operated several times or if reception is not performed normally. Further, the number to be added to the variable code is not limited to 1, but may be any number. Further, the numerical code to be used is not limited to four decimal digits, but may be any hexadecimal or octal digit.

On the other hand, when the battery 8 of the transmitting device 1 is replaced,
The RAM 6 is reset and the variable code is reset to 0000. Further, when the transmitting apparatus is idled more than the permissible change count number S (256 times in this embodiment), even the authorized transmitting apparatus 1 does not determine the variable code as the authorized variable code. Then, the process proceeds from Step 3 of FIG. 2 to Step 31 of the subroutine to perform the updating process. In this step 31, first, it is determined whether the variable n is 1 or not, that is, whether this routine is executed for the first time or for the second time or later.
= 1), 1 is added to the variable n in step 34,
A variable code contained in the currently received signal in step 35 is stored in the E ² PROM 13 as comparison code ends the process returns after step 5 of the main routine.
If the variable n is not 1 in step 31, that is, if this routine is executed for the second time or later,
In step 32, it is determined whether or not the variable code included in the signal received this time is equal to a value obtained by adding one count to the stored comparison code. It is determined whether or not 5, that is, whether or not Steps 31 to 35 of this routine have been performed five times. If so, the process proceeds to Step 36, where the variable n is set to the initial value 1 and the process proceeds to Step 5 of the main routine. Return The variable code received this time is stored in the E ² PROM 13 as a reference variable code. If it is determined in step 32 that the variable code included in the signal received this time is not equal to the stored comparison code obtained by adding one count, the process proceeds to step 37, where the variable n is set to an initial value of 1, and the main routine is executed. After, the return process ends.

In the above-described updating process, when the receiving device 2 receives a variable code having the same fixed code and increasing by 1 consecutively five times, the receiving device 2 stores the last received variable code as a reference variable code. is there. Therefore, in such a case, the signal is transmitted to the receiving device 2 by operating the switch 7 of the transmitting device 1 five times in succession, for example. In this way, even when the synchronization is lost, the transmitting device 1 can be recognized again as a legitimate transmitting device.

In the case of the keyless entry system for a vehicle, if the processes of steps 31 to 37 in FIG. 2 are performed by turning the ignition key switch of the vehicle 0N (or ACC) / 0FF a predetermined number of times, a predetermined number of times can be obtained. When the signal from the transmitting device is received within the time, and the fixed code included in the signal matches a preset regular fixed code, the variable code included in the received signal is determined to be a regular variable code. Can also be set to In this case, rather than verifying the authenticity of the transmission device itself, if the vehicle has a proper mechanical key, it is determined that the vehicle is a valid user of the vehicle, and the transmission device owned by the person is authorized. It is determined that the device is a transmitting device. In this embodiment, the signal is described as an infrared signal. However, it is needless to say that the same applies to the case where a radio wave or another signal propagation medium is used.

In this embodiment, each time a variable code is transmitted from the transmitting apparatus 1, a predetermined number (for example, 1) is added to the previously generated variable code and set as a new variable code. Although a numerical code that returns to the initial value a (for example, 0000) when the number exceeds N (for example, 9999) is used, a predetermined number (for example, 1) is added to the previously generated variable code every time a transmission is performed from the transmission device. Subtraction is set as a new variable code, and when this falls below a lower limit N (for example, 0000), an initial value a (for example, 999) is set.
The variable code A included in the signal received this time, the variable code A included in the signal received this time, the received code is confirmed to be the correct code received last time, and the stored variable code is the reference variable code B. Assuming that the allowable count number is S, if the variable code A included in the signal received this time is smaller than the reference variable code B, the fixed code included in the signal received this time is matched with a predetermined regular fixed code. If 1 ≦ BA ≦ S, a match signal is output and the variable code A received this time is stored as the reference variable code B. When the variable code A is larger than the reference variable code B, Outputs a match signal if the fixed codes match as above and a−N ≧ AB ≧ a−S−N + 1, and stores the variable code A received this time as the reference variable code B. You may do it.

Further, in the present embodiment, the difference between the count number of the previously received variable code (reference variable code) and the count number of the currently received variable code is represented by the above equation. However, the present invention is not limited to this. In the case of the digit addition counter, if the variable code A received this time <the reference variable code B, the difference between the count numbers may be virtually calculated as A = 10000 + A.

[0022]

As described above, according to the signal collation method of the present invention, even if the variable code cannot be identified between the transmitting device and the receiving device for some reason , the ignition key switch of the vehicle is operated a predetermined number of times. 0N / 0FF, after receiving a signal from the transmitting device within a predetermined time, if the fixed code included in the signal matches a predetermined regular fixed code, a variable code included in the received signal is used. Is determined to be a legitimate variable code, it is possible to confirm that the owner of the transmission device is the legitimate owner, so that the number of digits of the variable code does not need to be increased unnecessarily, and Maintenance after occurrence of such an error is also facilitated. In addition, if the variable code included in the signal and the previous variable code (reference variable code) stored in the receiving device are not the magnitude of the numerical value itself, but the difference in the count number changes within a predetermined range. If the variable code is regarded as a legitimate code, even if the variable code overflows and is reset to the initial value, the loop operates normally and the occurrence of the error itself is reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a main configuration of a portable transmitting device and a vehicle-side receiving device of a keyless entry system to which the present invention is applied.

FIG. 2 is a flowchart showing a signal collating procedure in the system of FIG. 1;

[Explanation of symbols]

1 transmitter 2 receiving apparatus 3 signal generation circuit 4 sends circuit 5 ROM 6 RAM 7 transmission switch 8 battery 11 receiving circuit 12 control unit 13 E ² PROM 14 door lock device

Claims (2)

(57) [Claims] A fixed code 1. A preset, to transmit a signal including a variable code which is changed by adding a predetermined change to the code previously generated whenever transmitting from a transmitting device, which locking apparatus for a vehicle Vehicle for use in remote control equipment
The fixed code included in the signal received this time and received by the receiving device provided on the side coincides with the preset regular fixed code, and the variable code included in the signal received this time is the previous regular code. If a predetermined change has been made to the variable code identified as being present, a match signal is output and the
In a signal collation method for locking / unlocking a lock device and storing a variable code received this time as a reference variable code to be used next time in the receiving device, the variable code is a predetermined variable with respect to the reference variable code.
If the vehicle has not changed the ignition
After the key switch is turned ON / OFF for a predetermined number of times,
Receiving a signal from the transmitting device within a predetermined time,
Is the same as the regular fixed code.
A signal collation method , wherein if it is, the variable code included in the signal can be stored in the receiving device as a reference variable code to be used next time. 2. The method according to claim 1, wherein the predetermined change is a change in a variable code included in a signal received this time within a predetermined count number with respect to a reference variable code stored in the receiving device. 2. The signal matching method according to 1.