Vehicle control device, code update method

Abstract

To improve security against a fraudulent act by a third person while maintaining convenience in operation for an authorized user.SOLUTION: A vehicle control device 1 comprises: a code memory part 12 that stores a reference code 12a for determining a correctness of a rolling code received from a portable unit 2; and a control part 11 that updates the reference code 12a stored in the code memory part 12 when the rolling code is received from the portable machine 2, and carries out a predetermined control of a vehicle 50 when a comparison result of the updated reference code and the received rolling code is normal. The control part 11 calculates a difference between the rolling code currently received from the portable machine 2 and the rolling code previously received from the portable machine 2, and updates the reference code 12a when predetermined renewal conditions individually set in correspondence to a magnitude of the difference are satisfied. Regarding the renewal conditions, the number of conditions to be satisfied increases as the difference between the rolling codes becomes larger.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a vehicle control device that controls the operation of a vehicle based on wireless communication between a vehicle and a portable device. [Background technology]

[0002] There is known a keyless entry system that controls the locking and unlocking of vehicle doors based on wireless communication between a portable device carried by a vehicle user and a vehicle control device mounted on the vehicle. In this system, a rolling code is used as a secret code included in the keyless signal transmitted from the portable device in order to increase the security of communication between the portable device and the vehicle control device.

[0003] The rolling code is a secret code that is updated according to a predetermined rule each time communication is performed. The transmitting portable device updates the rolling code each time it transmits a keyless signal. The receiving vehicle control device updates the rolling code (hereinafter referred to as the "reference code") that serves as the basis for judging whether the received rolling code is correct each time it receives a keyless signal. Patent documents 1 to 6 listed below disclose keyless entry systems that use such rolling codes.

[0004] FIG. 7 is a diagram for explaining the updating of the rolling code, showing an example in which the portable device is operated normally. Here, for simplicity, the rolling code is expressed as a two-digit number. When the user performs an operation to unlock the door on the portable device, the rolling code "11" is transmitted from the portable device as the currently transmitted value, as shown in FIG. 7(a). In this case, the previously transmitted value of the rolling code on the portable device was "10", and this is updated to become the currently transmitted value "11". The rolling code is included in the keyless signal that commands unlocking.

[0005] When the rolling code "11" is received by the vehicle, the currently received value on the vehicle side becomes "11". In addition, the reference code on the vehicle side is updated from the previous "10" to "11", the same as the currently received value. Since the currently received value "11" of the rolling code received from the portable device matches the updated reference code "11", the vehicle determines that the keyless signal received from the portable device is normal, and the doors are unlocked. Therefore, the user can get into the vehicle, start the engine, and drive the vehicle. When the user has finished using the vehicle, he or she locks the doors.

[0006] Thereafter, when the user operates the portable device to use the vehicle again, the updated rolling code is transmitted from the portable device. That is, as shown in FIG. 7(b), the previously transmitted rolling code "11" has been updated to "12" in the portable device, and this "12" is transmitted as the currently transmitted value. Meanwhile, when the vehicle receives the currently transmitted value "12", the reference code is updated from the previously transmitted "11" to "12". Then, since the currently received value "12" of the rolling code received from the portable device matches the updated reference code "12", the vehicle determines that the keyless signal transmitted by the portable device is normal, and the door is unlocked. This allows the user to use the vehicle.

[0007] Further, when the user operates the portable device to use the vehicle again, the updated rolling code is transmitted from the portable device. That is, as shown in FIG. 7(c), the previously transmitted rolling code "12" has been updated to "13" in the portable device, and this "13" is transmitted as the currently transmitted value. Meanwhile, when the currently transmitted value "13" is received in the vehicle, the reference code is updated from the previously transmitted "12" to "13". Then, since the currently received value "13" of the rolling code received from the portable device matches the updated reference code "13", the vehicle determines that the keyless signal transmitted from the portable device is normal, and the door is unlocked. This allows the user to use the vehicle. Thereafter, the same operation is repeated.

[0008] In this way, when the user performs normal operation, the rolling code on the portable device and the reference code on the vehicle are updated in synchronization with each other, so that no discrepancy occurs between the rolling codes of the portable device and the vehicle.

[0009] However, if the portable device is farther away from the vehicle than a certain distance, the signal transmitted from the portable device may not reach the vehicle, and the door may not be unlocked. Even if the portable device is close to the vehicle, an accidental communication error or the like may occur, and the signal transmitted from the portable device may not be received by the vehicle, and the door may not be unlocked. In such a case, the operation of the portable device will result in an erroneous operation, since the signal can be transmitted but not received by the vehicle.

[0010] However, even if there is an erroneous operation, the signal is transmitted from the portable device, so the rolling code is updated on the portable device side. On the other hand, the vehicle side does not update the reference code because it was not able to receive a signal from the portable device. Therefore, when an erroneous operation occurs, a deviation occurs in the rolling code between the portable device and the vehicle. As a result, even if the signal is repeatedly transmitted from the portable device, the transmitted rolling code does not match the reference code, so it becomes impossible to unlock the door. This will be specifically described with reference to Figs. 8A and 8B.

[0011] Fig. 8A(a) shows a case where an erroneous operation is performed on the portable device. In this case, the rolling code "11" is transmitted from the portable device to the vehicle, but this code is not received by the vehicle. Therefore, the reference code is not updated in the vehicle. Also, since the signal from the portable device is not received, the doors are not unlocked and the engine is not started.

[0012] Therefore, the user operates the portable device again to try to unlock the door. In this case, if the operation of the portable device is not an erroneous operation, the updated rolling code "12" is transmitted from the portable device to the vehicle as shown in FIG. 8A(b). Meanwhile, when the vehicle receives a signal from the portable device, the reference code is updated. However, since the reference code was not updated in FIG. 8A(a), the reference code is updated from "10" to "11" in FIG. 8A(b). As a result, although the rolling code received from the portable device is "12", the reference code is "11", and a discrepancy occurs between the two. In other words, the currently received value "12" does not match the reference code "11", and the door is not unlocked.

[0013] Therefore, the user further operates the portable device to try to unlock the door. If the operation of the portable device is not an erroneous operation, the updated rolling code "13" is transmitted from the portable device to the vehicle, as shown in FIG. 8A(c). Meanwhile, when the vehicle receives a signal from the portable device, the reference code is updated from "11" to "12." Therefore, in this case as well, there is a discrepancy in the rolling code between the portable device and the vehicle, and the door is not unlocked.

[0014] Similarly, as shown in Figures 8A(d) and 8B(e), the user repeatedly operates the portable device, but the deviation in the rolling code is not corrected, and the door remains unlocked.

[0015] In order to deal with such a situation, a process called "resynchronization" of the rolling code is performed. Resynchronization is a process in which, when a discrepancy occurs between the rolling codes of the portable device and the vehicle, the reference code on the vehicle side is corrected based on a predetermined operation by the user so that the rolling codes of both devices match. A specific example of resynchronization is described below.

[0016] For example, if an erroneous operation occurs because the portable device is too far away from the vehicle, the signal transmitted from the portable device is not received by the vehicle and the door is not unlocked, as described in FIG. 8A(a). However, if the user approaches the vehicle and operates the portable device again, the signal transmitted from the portable device can be received by the vehicle, as shown in FIG. 8A(b) and subsequent figures. However, when this operation is performed four times in succession as shown in FIG. 8A(b) to FIG. 8B(e), the misalignment of the rolling code between the portable device and the vehicle has not yet been resolved. Therefore, the door is not unlocked.

[0017] However, as shown in Fig. 8B(f), when the re-operation is performed five consecutive times, i.e., when the vehicle receives the rolling code from the portable device five consecutive times, the reference code on the vehicle side is updated from the previous "14" to the last rolling code received, "16". As a result, the rolling code on the portable device side and the reference code on the vehicle side both match and become "16", and the rolling codes are resynchronized. This resynchronization eliminates the mismatch between the rolling codes of the portable device and the vehicle, allowing the vehicle doors to be unlocked.

[0018] After resynchronization, the rolling code on the portable device and the reference code on the vehicle are updated in synchronization so that they are the same value. As long as there is no erroneous operation, there will be no deviation in the rolling code between the portable device and the vehicle, and normal operation similar to that shown in FIG. 7 will be performed, for example, as shown in FIG. 8B(g).

[0019] In this way, even if the vehicle doors cannot be unlocked due to an erroneous operation, the rolling code can be resynchronized by the user performing a specified operation on the portable device, thereby preventing the doors from remaining unlocked.

[0020] On the other hand, in a keyless entry system, the rolling code transmitted from the portable device of a legitimate user may be stolen by a malicious third party. For example, the third party may import the successive rolling codes transmitted from the portable device into his / her own wireless device. In this case, the third party may transmit the stolen rolling code from the wireless device and resynchronize the reference code on the vehicle side to illegally unlock the vehicle door. [Prior art documents] [Patent documents]

[0021] [Patent Document 1] Japanese Patent Application Publication No. 8-120987 [Patent Document 2] JP 2002-47838 A [Patent Document 3] JP 2000-314252 A [Patent Document 4] JP 2012-57368 A [Patent Document 5] JP 2017-128912 A [Patent Document 6] International Publication No. 2018 / 066244 Summary of the Invention [Problem to be solved by the invention]

[0022] An object of the present invention is to enhance security against fraudulent acts by third parties while maintaining convenience of operation for authorized users. [Means for solving the problem]

[0023] The vehicle control device according to the present invention includes a code storage unit that stores a reference code for judging whether a received rolling code is correct, and a control unit that updates the reference code stored in the code storage unit when a rolling code is received from a portable device, and performs a predetermined control on the vehicle when a comparison result between the updated reference code and the received rolling code is normal. The control unit calculates the difference between the rolling code currently received from the portable device and the rolling code previously received from the portable device, and updates the reference code when predetermined update conditions individually set according to the magnitude of this difference are satisfied. In the update conditions, the greater the difference in the rolling codes, the greater the number of conditions that must be satisfied.

[0024] According to the vehicle control device as described above, even if the user erroneously operates the portable device, if the difference in the rolling code is small, the reference code is updated by resynchronization, so that the user's convenience can be maintained. On the other hand, if the difference in the rolling code is large, the reference code is not updated unless an update condition according to the size of the difference is satisfied. Therefore, even if a third party performs an unauthorized operation, the risk of the reference code being updated by resynchronization can be reduced. Effect of the Invention

[0025] According to the present invention, it is possible to improve security against fraudulent acts by third parties while maintaining the convenience of operations for authorized users. [Brief description of the drawings]

[0026] [Figure 1] FIG. 1 illustrates an example of a vehicle control system. [Diagram 2] FIG. 2 is a diagram illustrating an example of a portable device. [Diagram 3] FIG. 4 is a diagram showing a format of a keyless signal. [Figure 4] 4 is a flowchart showing the operation of the portable device. [Diagram 5] 10 is a flowchart showing the operation of a timer. [Figure 6] 4 is a flowchart showing the operation of the vehicle control device. [Figure 7] FIG. 13 is a diagram illustrating the update of the rolling code in the case of normal operation. [Figure 8A] FIG. 13 is a diagram illustrating updating of the rolling code when an erroneous operation occurs. [Figure 8B] This is a continuation of Figure 8A. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. The same reference numerals are used throughout the drawings to designate the same or corresponding parts.

[0028] 1 shows a vehicle control system equipped with a vehicle control device according to the present invention. The vehicle control system 100 is composed of a vehicle control device 1 and a portable device 2. The vehicle control device 1 is an on-board device mounted on a vehicle 50, and performs wireless communication with the portable device 2. The portable device 2 is an electronic key operated when locking and unlocking a door 4 of the vehicle 50, and is carried by the user of the vehicle 50. When the user operates the portable device 2, a keyless signal K is transmitted from the portable device 2 to the vehicle control device 1. The vehicle control device 1 controls the locking and unlocking of the door 4 based on the received keyless signal K.

[0029] In FIG. 1, the vehicle control device 1 includes a control unit 11, a code storage unit 12, a ROM 13, a timer 14, a receiving unit 15, and an interface 16.

[0030] The control unit 11 is composed of a CPU and controls the operation of the vehicle control device 1. The code storage unit 12 is composed of a non-volatile memory and stores a rolling code 12a, which is a reference code, an ID code 12b, and a function code 12c. The ROM 13 stores the operation program and control parameters of the control unit 11. The timer 14 is composed of a counter and measures a preset time. The receiving unit 15 is composed of an antenna and a receiving circuit and receives the keyless signal K transmitted from the portable device 2. The interface 16 is composed of a connector to which the door controller 3 is connected, and is provided between the control unit 11 and the door controller 3. The door controller 3 outputs a lock signal for locking the door 4 or an unlock signal for unlocking the door 4 based on a command from the control unit 11.

[0031] In FIG. 1, the portable device 2 includes a control unit 21, an operation unit 22, a transmission unit 23, a ROM 24, a RAM 25, and a code storage unit .

[0032] The control unit 21 is made up of a CPU and controls the operation of the portable device 2. The operation unit 22 is provided with a lock switch 22a which is operated when locking the door 4 of the vehicle 50, and an unlock switch 22b which is operated when unlocking the door 4. The transmission unit 23 is made up of an antenna and a transmission circuit, and transmits a keyless signal K to the vehicle control device 1 based on the operation of the operation unit 22. The ROM 24 stores the operation program and control parameters of the control unit 21. The RAM 25 stores a format 25a of the keyless signal K including various codes as shown in FIG. 3. The code storage unit 26 is made up of a non-volatile memory and stores a rolling code 26a, an ID code 26b, and a function code 26c transmitted by the portable device 2.

[0033] 2 shows an example of the portable device 2. In addition to the above-mentioned operation unit 22, the portable device 2 is equipped with a mechanical key 27. If the door is not locked or unlocked by operating the operation unit 22, the user can lock or unlock the door by inserting the mechanical key 27 into a key hole of the door and performing a mechanical operation.

[0034] 4 is a flowchart showing the operation of the portable device 2. Each step in FIG.

[0035] In step S101, when the lock switch 22a or the unlock switch 22b of the operation unit 22 is operated, in step S102, the control unit 21 reads out the rolling code 26a and the ID code 26b from the code storage unit 26. The rolling code 26a at this time is the rolling code transmitted previously. Next, in step S103, the control unit 21 updates the rolling code 26a by an increment operation that adds 1 to the read rolling code 26a. This updated rolling code becomes the rolling code to be transmitted this time.

[0036] Next, in step S104, the control unit 21 stores in the RAM 25 the function codes corresponding to the operations of the lock switch 22a and the unlock switch 22b, the rolling code updated in step S103, and the ID code of the portable device 2, thereby updating the contents of the format 25a of the keyless signal K. After that, in step S105, the control unit 21 transmits the keyless signal K including a lock command or an unlock command from the transmission unit 23. After completing the transmission of the keyless signal K, in step S106, the control unit 21 writes the rolling code stored in the RAM 25 to the code storage unit 26. As a result, the rolling code 26a in the code storage unit 26 is rewritten to the currently transmitted rolling code.

[0037] Fig. 5 is a flow chart showing the operation of the timer 14 provided in the vehicle control device 1. The time measured by this timer 14 is used in step S11 in Fig. 6, the details of which will be described later.

[0038] First, in step S201, an initial value of the timer counter value T is set. In this example, the initial value is set to T=10 (unit: minutes). The timer 14 subtracts 1 from the timer counter value T every minute that passes from the start of operation until the timer counter value T becomes zero.

[0039] Specifically, when one minute has elapsed in step S202, the timer 14 performs a decrement operation to subtract one from the timer counter value T in step S203, setting T=T-1. Next, in step S204, the timer 14 determines whether the timer counter value T is zero, and if the timer counter value T is not zero, returns to step S202 and waits for one minute to elapse again. Then, when one minute has elapsed, the timer 14 further subtracts one from the timer counter value T in step S203, and determines whether the timer counter value T is zero in step S204. In the same manner, the operations of steps S202 to S204 are repeated until the timer counter value T becomes zero. Then, when the timer counter value T becomes zero in step S204, the operation of the timer 14 ends.

[0040] 6 is a flowchart showing the operation of the vehicle control device 1. Each step in FIG.

[0041] When the vehicle control device 1 receives the keyless signal K from the portable device 2, the control unit 11 determines in step S1 whether or not the ID code 26b (see FIG. 1) received from the portable device 2 matches the ID code 12b (see FIG. 1) stored in the code storage unit 12. If the two match, the control unit 11 determines in step S2 whether or not the function code 26c (see FIG. 1) received from the portable device 2 is valid. If the function code 26c corresponds to the function code 12c (see FIG. 1) stored in the code storage unit 12, the function code 26c is determined to be valid.

[0042] If the function code 26c is valid, the control unit 11 calculates the difference in the rolling codes in step S3. In detail, the difference is calculated between the rolling code currently received by the vehicle control device 1 from the portable device 2 (hereinafter referred to as the "currently received value") and the rolling code previously received by the vehicle control device 1 from the portable device 2 (hereinafter referred to as the "previously received value"). Then, depending on the magnitude of the calculated difference in the rolling codes, the control unit 11 performs the following process.

[0043] First, if the difference between the rolling codes is within the range of 1 to 30 (1≦difference≦30), the determination in step S4 becomes YES. Then, in step S5, the control unit 11 updates the reference code 12a in the code storage unit 12 from the previously received value to the currently received value. Here, "30", which is the upper limit of the difference range, corresponds to the "first threshold value" in the present invention.

[0044] Furthermore, if the difference between the rolling codes is within the range of 31 to 60 (31≦difference≦60), the determination in step S6 becomes YES. Then, in step S7, the control unit 11 refers to the update condition table Z and determines whether or not the update condition (a), which specifies that the rolling code is received five consecutive times, is satisfied. If the update condition (a) is satisfied as a result of the determination, the determination in step S7 becomes YES. Then, in step S8, the control unit 11 updates the reference code 12a in the code storage unit 12 to the fifth rolling code received among the five consecutive rolling codes received. Here, "60", which is the upper limit of the difference range, corresponds to the "second threshold value" in the present invention.

[0045] Furthermore, if the difference between the rolling codes is within the range of 61 to 100 (61≦difference≦100), the determination in step S9 becomes YES. Then, in step S10, the control unit 11 refers to the update condition table Z and determines whether or not both the update condition (a) and the update condition (b) that specifies that the door 4 of the vehicle 50 is in an unlocked state are satisfied. If the result of the determination is that both update conditions (a) and (b) are satisfied, the determination in step S10 becomes YES, and in step S8, the reference code is updated as described above. Here, the upper limit of the difference range, "100," corresponds to the "third threshold" in the present invention.

[0046] Furthermore, if the difference between the rolling codes is 101 or more (difference≧101), the determination in step S9 is NO. Then, in step S11, the control unit 11 refers to the update condition table Z and determines whether the update condition (a), the update condition (b), and the update condition (c) that specifies that 10 minutes or more have passed since it was determined that the difference between the rolling codes is 101 or more are all satisfied. Note that the update condition (c) is determined based on the timer counter value T of the timer 14 described above (see FIG. 5). If the determination results in that all of the update conditions (a), (b), and (c) are satisfied, the determination in step S11 is YES. Then, in step S8, the reference code is updated as described above.

[0047] In the embodiment shown in Fig. 6, conditions for updating the reference code are set individually according to the magnitude of the difference between the currently received value and the previously received value of the rolling code received from the portable device 2 (steps S7, S10, S11). Then, if the difference does not exceed the first threshold value of 30, the reference code is updated to the currently received rolling code regardless of whether the update condition is satisfied or not (step S5). On the other hand, if the difference exceeds the first threshold value, the respective update conditions according to the magnitude of the difference are satisfied, and the reference code is updated to the rolling code received for the fifth time (step S8). The reason for this is as follows.

[0048] If the difference between the rolling codes does not exceed the first threshold (=30), the reference code 12a in the code storage unit 12 is updated from the previously received rolling code to the currently received rolling code, regardless of the update conditions (a) to (c), in consideration of the possibility of an erroneous operation by a legitimate user. Therefore, the reference code can be updated normally without the user having to perform any special operation.

[0049] On the other hand, when the difference in the rolling code exceeds the first threshold, the possibility of an erroneous operation by a legitimate user is low, and the possibility of an unauthorized operation by a third party is high. This is because, in the case of a legitimate user, even if an erroneous operation is performed, after the erroneous operation is repeated several times, the user usually gives up unlocking with the portable device and unlocks the door with the mechanical key 27 described in FIG. 2, so the difference in the rolling code does not become large. On the other hand, when a third party performs an unauthorized operation, since it is impossible to unlock the door with the mechanical key, the third party will repeatedly steal and transmit the rolling code, and as a result, the difference in the rolling code will become large. Therefore, different update conditions are set according to the size of the difference, and since the possibility of an unauthorized operation by a third party increases as the difference becomes larger, the update conditions are made stricter by increasing the number of conditions to be satisfied.

[0050] For example, in step S7, if the rolling code is received five consecutive times (update condition (a)), the reference code is updated. This is because it is presumed that the authorized user has performed five consecutive operations similar to those in Figures 8A(b) to 8B(f). On the other hand, in step S10, in addition to the above conditions, it is required that the vehicle doors are unlocked (update condition (b)). This is because it is presumed that the doors have been unlocked using a mechanical key instead of a portable device. In this case, the operation is performed by a legitimate user who possesses a mechanical key, so updating of the reference code is permitted.

[0051] In addition to the above two conditions, step S11 also requires that 10 minutes or more must have elapsed (update condition (c)). This is done to prevent the reference code from being updated by resynchronization until 10 minutes have elapsed, thereby preventing a third party from tampering with the vehicle by unlocking the doors and stealing the vehicle during that time.

[0052] As described above, according to the present embodiment, the update conditions required for updating the reference code are set individually according to the magnitude of the difference between the rolling codes. The larger the difference is, the more conditions the update conditions must satisfy. On the other hand, if the difference does not exceed the first threshold, the reference code is updated to the currently received rolling code regardless of whether the set update conditions are satisfied.

[0053] Therefore, even if the user erroneously operates the portable device 2 several times, if the difference in the rolling code is small, the reference code is updated by resynchronization, so that the user's convenience can be maintained. On the other hand, if the difference in the rolling code is large, the reference code is not updated unless an update condition according to the size of the difference is satisfied. Therefore, even if a third party performs an unauthorized operation, the risk that the reference code is updated by resynchronization and the door is unlocked can be reduced. As a result, according to this embodiment, two problems can be simultaneously solved: maintaining the user's convenience and improving security against unauthorized acts by third parties.

[0054] In addition to the above-described embodiment, the present invention can employ various other embodiments as described below.

[0055] In steps S4, S6, and S9 in FIG. 6, the first threshold, the second threshold, and the third threshold are set to 30, 60, and 100, respectively, but this is merely an example, and each threshold may be set to another numerical value.

[0056] In step S8 of FIG. 6, the number of consecutive receptions of the rolling code is set to 5, but this is just an example, and the number of consecutive receptions may be set to another value.

[0057] In step S11 in Fig. 6, the elapsed time of the update condition (c) is set to 10 minutes, but this is just an example, and the elapsed time may be another value. In this case, the initial value of the timer counter value T in step S201 in Fig. 5 is changed.

[0058] In Fig. 6, if the update conditions are satisfied in steps S7, S10, and S11, the same process is performed in step S8, but different processes may be performed in each of steps S7, S10, and S11. For example, in step S10, the number of times in update condition (a) may be changed from 5 to 7, and in step S8, the number of times may be changed from 5 to 7. Similarly, in step S11, the number of times in update condition (a) may be changed from 5 to 10, and in step S8, the number of times may be changed from 5 to 10.

[0059] In FIG. 6, the update condition (b) is that the vehicle doors are unlocked. However, instead of or in addition to this, the update condition (b) may be that the vehicle engine is started. [Explanation of symbols]

[0060] 1 Vehicle control device 2. Portable Devices 4 Door 11 Control section 12 Code storage section 12a Rolling Code (Standard Code) 21 Control section 22 Control section 22a Lock switch 22b Unlock switch 26 Code storage section 26a Rolling Code 27 Mechanical Keys 50 vehicles 100 Vehicle Control System K Keyless Signal Z Update Condition Table

Claims

1. A vehicle control device that wirelessly communicates with a portable device carried by a vehicle user and performs a predetermined control of a vehicle based on receiving a transmission signal from the portable device, the transmission signal including a rolling code that is updated every time the portable device transmits a signal, the vehicle control device comprising: a code storage unit that stores a reference code for determining whether the received rolling code is correct; a control unit that updates the reference code stored in the code storage unit when the rolling code is received from the portable device, and performs a predetermined control on the vehicle when a comparison result between the updated reference code and the received rolling code is normal, The control unit is Calculating a difference between the rolling code currently received from the portable device and the rolling code previously received from the portable device; updating the reference code when a predetermined update condition that is individually set according to the magnitude of the difference is satisfied; A vehicle control device characterized in that the larger the difference, the greater the number of conditions that the update condition must satisfy.

2. The vehicle control device according to claim 1, The control unit is When the difference exceeds a first threshold value and is equal to or smaller than a second threshold value that is larger than the first threshold value, the update condition is that a rolling code has been received from the portable device a predetermined number of times in succession; If the update condition is met, update the reference code to the last received rolling code; A vehicle control device, characterized in that if the update condition is not satisfied, the reference code is not updated.

3. The vehicle control device according to claim 2, The control unit is When the difference exceeds the second threshold value and is equal to or smaller than a third threshold value that is larger than the second threshold value, the update condition is that a rolling code has been received from the portable device a predetermined number of times in succession and that a predetermined operation has been performed on the vehicle; If the update condition is met, update the reference code to the last received rolling code; A vehicle control device, characterized in that if the update condition is not satisfied, the reference code is not updated.

4. The vehicle control device according to claim 3, The control unit is When the difference exceeds the third threshold, the update conditions are that a rolling code has been received a predetermined number of times in succession from the portable device, that a predetermined operation has been performed on the vehicle, and that a predetermined time has elapsed; If the update condition is met, update the reference code to the last received rolling code; A vehicle control device, characterized in that if the update condition is not satisfied, the reference code is not updated.

5. A code update method in a vehicle control device, which wirelessly communicates with a portable device carried by a user of a vehicle, receives from the portable device a transmission signal including a rolling code that is updated each time the portable device transmits, and performs a predetermined control on the vehicle when a comparison result between a reference code that is updated when the rolling code is received from the portable device and the received rolling code is normal, comprising: calculating a difference between a rolling code currently received from the portable device and a rolling code previously received from the portable device; determining whether or not a predetermined update condition that is individually set according to the magnitude of the difference is satisfied; updating the reference code if the predetermined update condition is met; A code updating method, characterized in that the larger the difference, the greater the number of conditions that the update condition must satisfy.

Images