JPH11336395A - On-board equipment remote control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an on-board equipment remote control device capable of impeding action control of on-board equipment using a copied return signal by changing the ID code encoding pattern of return signals transmitted from a portable apparatus every transmission demand. SOLUTION: With every transmission demand from the vehicle side, random code signals of different patterns are transmitted being included in transmission demand signals. An ID code is transmitted being encoded using a random code included in the transmission demand signal received by a portable apparatus, and a code included in a return signal received on the vehicle side is decoded by the random code used in the transmission demand and judged as to whether it coincides with a preset ID code (S24). The ID code encoding pattern of the return signals transmitted from the portable apparatus every transmission demand can therefore be changed, so that action control of on-board equipment using the copied return signal can be impeded.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an on-vehicle device remote control device, and more particularly to a device for remotely controlling on-vehicle devices.

[0002]

2. Description of the Related Art Conventionally, there is a so-called smart entry system in which a user carries a wireless device to open / lock a door of a vehicle simply by approaching / leaving the vehicle. For example, Japanese Patent Application Laid-Open No. 62-37479 discloses that a request command is intermittently transmitted from a vehicle side, and a unique code signal is returned from a portable device receiving the request command in response to the request command. A device is described which receives a signal, determines a match with a unique code, and locks a door of a vehicle when transmission of a code signal from a portable device is interrupted.

[0003]

Since the portable device always receives the request command for portable device search and detects the vehicle, the portable device consumes a considerable amount of power with respect to the battery capacity. For this reason, the portable device needs to have a circuit configuration with extremely low power consumption. Here, in the conventional device, since the request command is intermittently transmitted from the vehicle, if the request code is a fixed code, the request code is copied, and the user who owns the portable device of the vehicle leaves the vehicle. Then, by transmitting the copied request code near the user, the unique code signal returned from the portable device is received and copied. Then, when the user is absent, a unique code signal transmitted from the vehicle in response to the request code transmitted from the vehicle in the vicinity of the vehicle can unlock the vehicle door, and the vehicle can be stolen. There is a problem that the nature occurs.

[0004] By the way, a request code (a unique code is plain text) is used for each vehicle (portable device), and this is used as, for example, a DES (Data Encryption) of a symmetric key cryptosystem.
It is also conceivable to transmit a ciphertext as a ciphertext using a key such as an Ion Standard) and return the received ciphertext to a plaintext using a key with a portable device (vehicle). If copied, the door of the vehicle can be unlocked by transmitting the ciphertext of this unique code near the vehicle, and there is a problem that theft of the vehicle cannot be prevented.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and by changing the ID code encryption pattern of a return signal transmitted from a portable device for each transmission request, an in-vehicle device using the copied return signal is provided. It is an object of the present invention to provide an on-vehicle device remote control device capable of preventing the operation control of the device.

[0006]

According to a first aspect of the present invention, there is provided a vehicle, comprising: transmission request means for transmitting a transmission request signal instructing a transmission request; A portable device for transmitting a return signal including an ID code to be specified; a receiving unit provided in the vehicle for receiving a return signal transmitted from the portable device; and a return device provided for the vehicle and received by the receiving unit. ID included in the signal
An on-vehicle equipment remote control device having control means for controlling the operation of the on-vehicle equipment when the code matches a preset ID code, a signal of a random code having a different pattern provided for each transmission request provided in the vehicle. Random code generating means for transmitting the random number included in the transmission request signal; encoding means provided in the portable device for encoding and transmitting the ID code using a random code included in the received transmission request signal; Provided,
Decoding means for decoding a code included in the return signal received by the receiving means with the random code used in the transmission request and for determining a match with the preset ID code.

[0007] As described above, a signal of a random code having a different pattern is transmitted from the vehicle to the transmission request signal for each transmission request, and the ID code is encoded using the random code included in the transmission request signal received by the portable device. By transmitting and decoding the code included in the return signal received by the vehicle with the random code used in the transmission request and making a match with a preset ID code, It is possible to change the ID code encryption pattern of the return signal transmitted from the device, thereby preventing the operation control of the vehicle-mounted device using the copied return signal.

According to a second aspect of the present invention, in the on-vehicle device remote control device according to the first aspect, the frequency of the transmission request signal is made different from the frequency of the return signal. In this way, by making the frequency of the transmission request signal and the frequency of the return signal different, the transmission of the transmission request signal from the vehicle side and the transmission of the return signal from the portable device can be performed simultaneously. The operation control of the device can be performed quickly.

According to a third aspect of the present invention, in the on-vehicle device remote control device according to the first or second aspect, the portable device encodes the ID code based on a random code included in the received transmission request signal. For generating a new code having a larger number of bits than the random code.

As described above, since a new code having a larger number of bits than the received random code is generated and the ID code is encoded, the code pattern of the new code can be complicated, and the risk of decoding is reduced. As a result, communication security can be improved. According to a fourth aspect of the present invention, in the on-vehicle device remote control device according to the third aspect, the code generation means generates the new code by repeating the random code.

Thus, a new code can be easily generated by repeating the random code. According to a fifth aspect of the present invention, in the on-vehicle device remote control device according to the third aspect, the code generation means generates a new code by performing a predetermined operation on the random code in bit units.

As described above, since a new code is generated by performing a predetermined operation on a random code in units of bits, the new code can be formed into a complicated pattern, and the risk of decryption is reduced and communication security is reduced. Performance can be improved.

[0013]

FIG. 1 is a block diagram showing an embodiment of the apparatus according to the present invention. In FIG. 1, a vehicle block 10 is provided in a vehicle, and a transmitter 12 in the vehicle block 10 is controlled by a control device 14 to modulate a request code (PWM code: pulse width modulation code) having a predetermined code pattern. The generated transmission request signal is generated and transmitted from the antenna 16. Further, after transmitting the request code, under the control of the control unit 14, a transmission request signal obtained by modulating a random code (PWM code) supplied from the random code generation unit 18 is generated and transmitted from the antenna 16. The code pattern of the random code changes for each request, and the transmission request signal is, for example, an AM modulated signal having a frequency of 134.2 KHz.

The portable device 30 carried by the user receives the transmission request signal from the transmitter 12 by the antenna 32 and performs AM demodulation by the receiving unit 34. When the demodulated data matches the request code of the predetermined code pattern set in advance, the receiving unit 34 sends a trigger signal to wake up the portable device 30 by using the ID code generating unit 36, the encoding unit 38, and the transmitting unit 40. And activate them. Thereafter, when the random code is AM-demodulated and output by the receiving unit 34, the ID code generating unit 36 serially outputs an ID code of a preset unique code pattern, and the ID code is transmitted to the encoding unit 38. Supplied. Further, the demodulated random code is supplied from the receiving unit 34 to the encoding unit 38 as an encryption key.

The switch 37 is a normally open switch, and when pressed by a user, generates a trigger signal and supplies it to the ID code generator 36 and the receiver 34. Is serially output and supplied to the encoding unit 38. In response to the trigger, the receiving unit 34 supplies the value “0” to the encoding unit 38 to stop the encryption of the ID code.

The encoding unit 38 includes an ID code generation unit 36
Is encoded by a random code as an encryption key supplied from the receiving unit 34,
The obtained encryption code (PWM code) is supplied to the transmission unit 40. The transmission unit 40 generates a return signal obtained by modulating the supplied encryption code, and transmits the return signal from the antenna 42. This return signal is, for example, an AM modulated signal having a frequency of 300 MHz.

The receiver 20 in the vehicle block 10 receives the return signal transmitted from the portable device 30 by the antenna 22, demodulates the encryption code, and supplies it to the decoding unit 24.
The random code generated by the random code generator 18 is read out from the register 26 with a delay of a predetermined time and supplied serially to the decoding unit 24 as an encryption key. The code is decoded to restore the ID code. The delay time of the reading in the register 26 corresponds to the time until the return signal of the encryption code is received from the portable device 30.
The restored ID code is supplied to the control unit 14, and the control unit 14 compares the restored ID code with a preset ID code, and when they match, sends a control signal to the drive unit 28 of the door lock motor. To perform door lock or door unlock.

FIG. 2 shows a flowchart of one embodiment of the smart entry process executed by the control unit 14 of the vehicle block 10. In the figure, the control unit 14 activates the receiver 20 in step S10. Next, in step S12, the time T
1 (T1 is, for example, 10 to 20 msec), and it is determined in step S14 whether or not the receiver 20 has received a portable device transmission signal. Here, when the portable device transmission signal is received, it is a portable device transmission signal by operating the switch 37, and the process proceeds to step S16 to perform a switch operation process.
That is, in step S16, if the door is locked, the drive unit 28 is drive-controlled to unlock the door. If the door is unlocked, the drive unit 28 is drive-controlled to lock the door.

Here, if the portable device transmission signal has not been received, a request code is generated in step S18.
Next, in step S20, it is determined whether or not the return signal has been received by the receiver 20, and if it has been received, the process proceeds to step S22.
To continue receiving the return signal. At the same time, transmitter 1
The random code from the random code generation unit 18 is transmitted through 2. Then, in step S24, it is determined whether or not the ID code obtained by decoding the encryption code of the return signal matches the preset ID code. If the ID code matches, the smart entry control is executed in step S26. To step S10. That is, step S2
In step 6, when the door is locked, the drive unit 28 is driven and controlled to unlock the door. On the other hand, if the return signal cannot be received in step S20, and if the ID codes do not match in step S24, the process waits for a predetermined time T2 in step S28 and proceeds to step S10.

Here, the ID code generator 3 of the portable device 30
The ID code generated at 6 is 15 as shown in FIG.
Bit code pattern "10101011011001"
01 "and the random code supplied from the receiving unit 34 is a 4-bit code pattern" 1010 "as shown in FIG. 3B, the encoding unit 38 performs, for example, an exclusive OR operation. Figure 3
A 15-bit encryption code is generated as shown in FIG.

In this case, the decoding section 24 of the vehicle block 10 exchanges the received and demodulated code shown in FIG. 3C with the random code read out with a delay shown in FIG. 3B. Perform a sieve-or operation, and see FIG.
Is restored. Note that the random code does not need to be synchronized with the ID code. However, the time from the transmission of the random code from the transmitter 12 in the vehicle block 10 to the reception and demodulation of the encryption code by the receiver 20 is slightly different from the read delay time of the register 26. , The bit period of the random code is I
It is realistic to set a large value for the bit period of the D code.

As described above, a signal of a random code having a different pattern is included in the transmission request signal from the vehicle block 10 for each transmission request and transmitted, and the ID is generated by using the random code included in the transmission request signal received by the portable device 30. To encode and transmit the code, decode the code included in the return signal received by the vehicle block 10 with the random code used in the transmission request, and determine whether the code matches the preset ID code. Copy the request code and random code sent from block 10,
By transmitting the request code and the random code copied in the vicinity of the user when the user owning the portable device of the vehicle leaves the vehicle, receiving and copying the encryption code returned from the portable device, When the user is absent, even if the copied encrypted code is transmitted in accordance with the transmission of the request code and the random code from the vehicle in the vicinity of the vehicle, the random code is changed for each request, and the random code is changed. , The encryption code generated at the time of the previous request cannot unlock the door of the vehicle, thereby preventing the vehicle from being stolen.

Further, by making the frequency of the transmission request signal different from the frequency of the return signal, transmission of the transmission request signal from the vehicle side and transmission of the return signal from the portable device can be performed simultaneously. The operation control of the in-vehicle device can be quickly performed. To make the frequency of the transmitter signal different here means to change the frequency order, unlike performing channel separation in the same frequency band and performing two-way communication. It is easy for the vehicle side to form a receiver with sufficient frequency selectivity, while the portable side cannot realize sufficient frequency selectivity due to current consumption. Prevents a signal from the vehicle from being unreceivable by the return signal.

Here, in the case of the smart entry system, the transmission request signal transmitted from the transmitter 12 is shown in FIG.
The request code has a predetermined bit pattern of a PWM code as shown in FIG. The smart entry system that locks / unlocks the door sends this transmission request signal to the outside of the vehicle, but the smart ignition, which automatically starts the engine when the driver gets into the driver's seat, sends the transmission request signal inside the vehicle. Send to.

In the case of the smart ignition, the transmission request signal is a request code having a predetermined bit pattern of a PWM code as shown in FIG. FIG.
In (A) and (B), the lower 4 bits are different. Further, when instructing the portable device 24 to sleep, the transmission request signal is a request code having a pattern of all bit values 1 of the PWM code as shown in FIG. Note that this P
In the WM code, the bit cycle is constant and the duty ratio is 2
In the case of / 3, the value is “1”, and when the duty ratio is ３, the value is “0”.

The ID code generator 36 of the portable device 30 to which the transmission request signal of the above-mentioned smart entry, smart ignition and sleep instruction is supplied decodes the bit pattern of the transmission request signal from the received signal, and FIG.
4B, a smart entry transmission request is performed with the bit pattern request code of FIG. 4B, and a smart ignition transmission request is performed with the bit pattern request code of FIG. 4C. Recognize that this is an instruction transmission request. Then, a 3-bit status is generated based on a trigger based on this recognition and the presence / absence of a lock / unlock trigger signal from the switch 37. If the triggers overlap, set a priority, lock / unlock, smart ignition,
Lower the priority in the order of smart entries.

The ID code generator 3 of the portable device 30
6 generates a return signal in a code format as shown in FIG. In FIG. 5, a synchronization header section is provided following the preamble section, and an ID code section, a status section, and an ECC (error correction code) section are provided subsequently.
The bit patterns of the preamble portion, the header portion, and the ID code portion are fixed, and the status portion stores the 3-bit status generated as described above.

The ID code stored in the ID code section is encoded by a random code in the encoding section 38 of FIG. 1, but the other preamble section, header section, status section, and ECC section need to be encoded. Therefore, at these output timings, the vehicle-side random code generator 18 supplies the value “0” to stop the encryption.

FIG. 6 is a circuit diagram showing a second embodiment of the portable device. In the figure, a signal received by an antenna 32 is supplied to a detection unit 50 in a reception unit 34, where a signal having a frequency 13
A transmission request signal of 4.2 KHz is detected. This detection output is supplied to a comparator 52 in the transmission unit 30, where it is binarized, shifted and input to an input data register 54, and stored sequentially. The data stored in the input data register 54 is compared with the bit pattern of the request code stored in the data comparator 56 in advance.

When the input data matches the bit pattern of the request code, the data comparator 56 generates a trigger signal and supplies it to the ID code generator 36, the encoder 38 and the transmitter 40. Thereafter, after the random code demodulated from the received signal is stored in the input data register 54, the ID code generator 36 uses the clock from the clock oscillator 58 to convert the ID code of the preset unique code pattern. Output serially. At the same time, the clock generated by the clock oscillator 58 is supplied to the input data register 54.

The input data register 54 shifts out the stored random code using the clock. The random code shifted out from the input data register 54 is supplied to the encoding unit 38.
It is looped back to the input of the input data register 54 and shifted in. For this reason, the random code is repeatedly read from the input data register 54 and supplied to the encoding unit 38 as an encryption key. Encoding unit 3
Numeral 8 encodes the ID code supplied from the ID code generation unit 36 with the random code supplied from the reception unit 34, and supplies the obtained encryption code to the transmission unit 40.
The transmission unit 40 generates a return signal obtained by modulating the supplied encryption code, and transmits the return signal from the antenna 42.

Here, for example, a 5-bit random code "10110" is stored in the input data register 54 of the portable device 30.
Is stored and shifted out of the MSB, the I code generated by the ID code generation unit 36 of the portable device 30 is generated.
If the D code is a 15-bit code pattern “1010101101100101” as shown in FIG. 7A, the random code supplied from the input data register 54 of the receiving unit 34 is a 15-bit code pattern as shown in FIG. Code pattern “101101011010110”
The 15-bit encryption code generated by the exclusive OR operation in the encoding unit 38 is shown in FIG.
It becomes as shown in. Of course, also in the vehicle block 10, the 5-bit random code is repeatedly read from the register 26.

In this embodiment, since the ID code and the random code are synchronized at the time of generation of the encryption code in the portable device 30, each bit width of the encryption code becomes constant and there is no possibility of noise generation. . Further, since the number of bits of the code as the encryption key can be increased more than the number of bits of the random code transmitted from the vehicle block 10 and the code pattern can be complicated, the risk of decryption is reduced. Safety can be improved.

Next, another embodiment for generating a code of an encryption key from a random code in the portable device 30 will be described.
This will be described with reference to the circuit configuration diagram of FIG. 5, the input data register 54 is constituted by a flip-flop (FF) 60 ₁ ~60 ₅ connected in cascade. Switch 62 at the time of reception of the random code random code supplied from the comparator 52 to the terminal 64 selects the terminal A is stored is sequentially shifted flip flops 60 ₁ to 60 ₅ in clock supplied from the terminal 66.

[0035] When generation of an encryption code, clock generated by the clock generator 58 is supplied from the terminal 66, the random code stored in the flip-flop _{601 through} 603 ₅ is shifted out the encoding unit from the terminal 68 as a key cryptography 38, and to the exclusive OR circuit 70. Exclusive-The Inclusive OR circuit 70 is supplied with the flip-flop 60 _2, 60 _5, respectively of the output data, wherein the arithmetic operation result is supplied to the terminal B of the switch 62. At this time,
Switch 62 outputs the data of the exclusive OR circuit 70 is supplied to the flip-flop 60 ₁ selects the terminal B. In the vehicle block 10, the register 2
Of course, the same logical operation is performed from the random code No. 6 to generate a code as a key for encryption.

As described above, the exclusive OR circuit 7
In order to generate a cryptographic key code from a random code by providing a logical operation circuit such as 0, not only the number of bits of the code as a cryptographic key can be increased than the number of bits of the random code, The code pattern becomes complicated, and the security of communication can be improved by reducing the risk of decryption.

It should be noted that the transmitter 12 corresponds to transmission request means, the receiver 20 corresponds to reception means, the control section 14 corresponds to control means, the random code generation section 18 corresponds to random code generation means, The encoding unit 38 corresponds to the encoding unit, the decoding unit 24 corresponds to the decoding unit, and the input data register 54 and the flip-flop 60 ₁
60 _5, switch 62, the exclusive-OR circuit 7
0 corresponds to code generation means.

[0038]

As described above, the first aspect of the present invention provides
A random code generator provided in the vehicle and transmitting a random code signal having a different pattern for each transmission request in the transmission request signal; and a random code included in the portable device and included in the received transmission request signal. Encoding means for encoding and transmitting the ID code, and a code included in the return signal received by the receiving means, which is provided in the vehicle, is decoded by a random code used in a transmission request, and is set to the preset value. Decoding means for making a match determination with the ID code.

As described above, the vehicle transmits the transmission request signal including a random code signal having a different pattern for each transmission request, and encodes the ID code using the random code included in the transmission request signal received by the portable device. By transmitting and decoding the code included in the return signal received by the vehicle with the random code used in the transmission request and making a match with a preset ID code, It is possible to change the ID code encryption pattern of the return signal transmitted from the device, thereby preventing the operation control of the vehicle-mounted device using the copied return signal.

According to the second aspect of the present invention, the frequency of the transmission request signal is made different from the frequency of the return signal. In this way, by making the frequency of the transmission request signal and the frequency of the return signal different, the transmission of the transmission request signal from the vehicle side and the transmission of the return signal from the portable device can be performed simultaneously. The operation control of the device can be performed quickly.

According to the third aspect of the present invention, the portable device uses a new code having a larger number of bits than the random code used for encoding the ID code based on the random code included in the received transmission request signal. Code generating means for generating a simple code. in this way,
Since a new code having a larger number of bits than the received random code is generated and the ID code is encoded, the code pattern of the new code can be complicated, and the security of communication can be reduced by reducing the risk of decoding. Can be improved.

According to the invention described in claim 4, the code generation means generates the new code by repeating the random code. Thus, a new code can be easily generated by repeating the random code. In the invention according to claim 5, the code generation means performs a predetermined operation on the random code in bit units to generate the new code.

As described above, since a new code is generated by performing a predetermined operation on a random code in units of bits, a new code can be formed into a complicated pattern, and the risk of decryption is reduced and communication security is reduced. Performance can be improved.

[Brief description of the drawings]

FIG. 1 is a block diagram of the device of the present invention.

FIG. 2 is a flowchart of one embodiment of a smart entry process executed by a control unit 14 of the vehicle block 10;

FIG. 3 is a diagram showing a code pattern of each of an ID code, a random code, and an encryption code according to the present invention.

FIG. 4 is a diagram illustrating a bit pattern of a transmission request signal.

FIG. 5 is a diagram showing a format of a return signal.

FIG. 6 is a circuit configuration diagram of a second embodiment of the portable device.

FIG. 7 is a diagram showing a code pattern of each of an ID code, a random code, and an encryption code according to the present invention.

FIG. 8 is a circuit configuration diagram of another embodiment of a circuit for generating an encryption key code from a random code.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Vehicle block 12 Transmitter 14 Control device 16, 22, 32, 42 Antenna 18 Random code generation part 20 Receiver 24 Decoding part 26 Register 28 Driving part 30 Portable device 34 Receiving part 36 ID code generation part 37 Clock oscillator 38 Encoding part REFERENCE SIGNS LIST 40 transmission unit 50 detection unit 52 comparator 54 input data register 56 data comparator 58 clock oscillator 60 _{1 to} 60 ₅ flip-flop 62 switch 70 exclusive OR circuit

Claims (5)

[Claims] 1. A transmission device provided in a vehicle for transmitting a transmission request signal instructing a transmission request, and a portable device receiving the transmission request signal and transmitting a return signal including an ID code for identifying the own device. And receiving means provided in the vehicle and receiving a return signal transmitted from the portable device; and an ID provided in the vehicle and having an ID code included in the return signal received by the receiving means set in advance. An on-vehicle device remote control device having control means for controlling the operation of the on-vehicle device when the code matches the code, wherein the transmission request signal includes a signal of a random code having a different pattern for each transmission request and provided in the vehicle. Random code generating means, provided in the portable device, encoding the ID code using a random code included in the received transmission request signal, and transmitting the encoded ID code And an encoding unit for decoding the code included in the return signal received by the receiving unit, which is provided in the vehicle, with the random code used in the transmission request, and performing a match determination with the preset ID code. An in-vehicle device remote control device, comprising: decoding means. 2. The on-vehicle device remote control device according to claim 1, wherein the frequency of the transmission request signal is different from the frequency of the return signal. 3. The on-vehicle device remote control device according to claim 1, wherein the portable device uses the random code to encode the ID code based on a random code included in a received transmission request signal. An in-vehicle device remote control device, comprising: code generation means for generating a new code having a larger number of bits. 4. The on-vehicle device remote control device according to claim 3, wherein the code generation means generates the new code by repeating the random code. 5. The on-vehicle device remote control device according to claim 3, wherein said code generation means generates a new code by performing a predetermined operation on said random code in bit units. Control device.