Control device and control method

Abstract

To provide a control device capable of preventing the failure of an encrypted communication connection between an electric vehicle and a power station.SOLUTION: A charging control ECU 10 (control device) includes a processor 11 that performs control to connect TLS communication (encrypted communication) by specifying a cipher suite (encryption method), and a communication unit 13 (acquisition unit) that acquires information regarding the compatibility of the cipher suite specified by the processor 11 with an EVSE 200. When the information indicates that the cipher suite is incompatible with the EVSE 200, the processor 11 performs control to change the cipher suite and connect the TLS communication.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present disclosure relates to a control device and a control method. [Background technology]

[0002] JP 2022-061185 A (Patent Document 1) discloses a charging device and a vehicle that performs charging authentication by acquiring charging side information transmitted from the charging device. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2022-061185 Summary of the Invention [Problem to be solved by the invention]

[0004] Although not specified in Patent Document 1, when connecting encrypted communication (such as TLS communication) between a vehicle (electric vehicle) and a charging device (power station), it is necessary to specify the encryption method (cipher suite) to be used for the encrypted communication. A determination is made as to whether the specified encryption method is applicable to the charging device. If the specified encryption method is incompatible with the charging device, the encrypted communication cannot be connected.

[0005] The present disclosure has been made to solve the above-mentioned problems, and its purpose is to provide a control device and a control method that are capable of preventing the establishment of an encrypted communication connection between an electric vehicle and a power station from being failed. [Means for solving the problem]

[0006] A control device according to a first aspect of the present disclosure is a control device that controls encrypted communication between an electric vehicle and a power station, and includes a processor that performs control to specify an encryption method and connect the encrypted communication, and an acquisition unit that acquires information regarding the compatibility of the encryption method specified by the processor with the power station. When the information indicates that the encryption method is incompatible with the power station, the processor performs control to change the encryption method and connect the encrypted communication.

[0007] In the control device according to the first aspect of the present disclosure, as described above, when the information indicates that the encryption method is incompatible with the power station, control is performed to change the encryption method and connect the encrypted communication. As a result, even if the encryption method is incompatible with the power station, the encryption method is changed and the connection process for the encrypted communication is executed, so that it is possible to prevent the process from terminating without connecting the encrypted communication. Therefore, it is possible to prevent the connection for the encrypted communication between the electric vehicle and the power station from being broken.

[0008] In the control device according to the first aspect, the processor preferably, when connecting encrypted communication between a first power station that has a track record of successful encrypted communication connection in the past and an electric vehicle, designates, with priority, as an encryption method to be used for the encrypted communication, an encryption method that has a track record of successful encrypted communication connection in the past at the first power station. With this configuration, it is possible to preferentially use, for the encrypted communication, an encryption method that has a track record of successful encrypted communication connection, and therefore to prevent an encryption method that is incompatible with the power station from being used for the encrypted communication.

[0009] In the control device according to the first aspect, the processor preferably specifies, when connecting the encrypted communication between the second power station with which the encrypted communication has not been previously connected and the electric vehicle, an encryption method having a higher encryption strength as the encryption method to be used for the encrypted communication, rather than an encryption method having a lower encryption strength for the encrypted communication. With this configuration, it is possible to prevent the encryption strength of the encrypted communication from being reduced.

[0010] In the control device according to the first aspect, the processor preferably controls connection of encrypted communication with the power stand in a PnC in which billing authentication and charging are automatically performed in response to connection of a connector of the power stand to an electric vehicle. Here, in the PnC, a standard stipulates that encrypted communication is performed in order to conceal communication information between the electric vehicle and the power stand. Therefore, changing the encryption method and connecting encrypted communication when the encryption method is incompatible with the power stand is particularly effective when performing encrypted communication in the PnC.

[0011] A control method according to a second aspect of the present disclosure is a control method for controlling encrypted communication between an electric vehicle and a power station, and includes a step of performing control to connect the encrypted communication by specifying an encryption method, and a step of acquiring information on the compatibility of the specified encryption method with the power station. The step of performing control to connect includes a step of performing control to change the encryption method and connect the encrypted communication when the information indicates that the encryption method is incompatible with the power station.

[0012] In the control method according to the second aspect of the present disclosure, when the information indicates that the encryption method is incompatible with the power station as described above, control is performed to change the encryption method and connect encrypted communication. This makes it possible to provide a control method that can prevent the connection of encrypted communication between the electric vehicle and the power station from being broken. Effect of the Invention

[0013] According to the present disclosure, it is possible to prevent the establishment of an encrypted communication connection between an electric vehicle and a power station from being interrupted. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a diagram illustrating a configuration of a system according to an embodiment. [Diagram 2] FIG. 4 is a diagram illustrating information stored in a memory of a charging control ECU according to one embodiment. [Diagram 3] FIG. 13 is a diagram showing an example of an EVSE search screen on an HMI device according to an embodiment. [Figure 4] FIG. 4 is a sequence diagram showing control of the system according to one embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference characters and the description thereof will not be repeated.

[0016] 1 is a diagram showing a configuration of a system 1 according to this embodiment. The system 1 includes an electric vehicle 100 and an EVSE (Electric Vehicle Supply Equipment) 200. The EVSE 200 is an example of a "power station" in the present disclosure.

[0017] The electric vehicle 100 includes, for example, a plug-in hybrid electric vehicle (PHEV), a battery electric vehicle (BEV), or a fuel cell electric vehicle (FCEV). A battery 20 (described later) of the electric vehicle 100 stores electric power for driving the electric vehicle 100.

[0018] EVSE 200 refers to a power supply facility for vehicles. Electrically-powered vehicle 100 is configured to be electrically connectable to EVSE 200. EVSE 200 includes a charging cable 220 to which a connector 210 is attached. When connector 210 is connected to an inlet (not shown) of electric vehicle 100, electric power can be exchanged between EVSE 200 and electric vehicle 100.

[0019] Specifically, external charging is performed between the electric vehicle 100 and the EVSE 200. External charging refers to transmitting electric power stored in the battery 20 of the electric vehicle 100 to the EVSE 200 via the connector 210 (charging cable 220).

[0020] In this embodiment, external charging by PnC (Plug and Charge) is possible between the electric vehicle 100 and the EVSE 200. PnC refers to a charging method in which processes such as billing authentication and charging are automatically executed by simply connecting the connector 210 of the EVSE 200 to the electric vehicle 100.

[0021] The electric vehicle 100 includes a charge control ECU (Electric Control Unit) 10, a battery 20, and an HMI (Human Machine Interface) device 30. The charge control ECU 10 is an example of a "control device" in the present disclosure.

[0022] The charging control ECU 10 includes a processor 11, a memory 12, and a communication unit 13. The memory 12 and the communication unit 13 are examples of a "recording unit" and an "acquisition unit" in the present disclosure, respectively.

[0023] Processor 11 controls Transport Layer Security (TLS) communication between electric vehicle 100 and EVSE 200. Specifically, processor 11 performs control to connect TLS communication by specifying a cipher suite. Note that a cipher suite refers to a set of encryption algorithms used in TLS communication. Note that TLS communication and a cipher suite are examples of "encrypted communication" and "encryption method" in the present disclosure, respectively.

[0024] The memory 12 stores information used in the programs (for example, maps, formulas, and various parameters) in addition to the programs executed by the processor 11. Specifically, the memory 12 stores information on cipher suites available for use in the electric vehicle 100. In this embodiment, it is assumed that the electric vehicle 100 can use a cipher suite called TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA256 (hereinafter referred to as cipher suite A), a cipher suite called TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256 (hereinafter referred to as cipher suite B), a cipher suite called TLS_AES_256_GCM_SHA256 (hereinafter referred to as cipher suite C), and a cipher suite called TLS_CHACHA_POLY1305_SHA256 (hereinafter referred to as cipher suite D). Each of the cipher suites A and B is a cipher suite that complies with the ISO15118-2 standard. Additionally, each of cipher suites C and D is a cipher suite that complies with the ISO15118-20 standard.

[0025] 2, the memory 12 records information about combinations of EVSE 200 and cipher suites that have been successful in TLS communication connections in the past. In the example shown in FIG. 2, the combination of EVSE_A and cipher suite A has been successful in TLS communication connections in the past. The combination of EVSE_B and cipher suite B has been successful in TLS communication connections in the past. The combination of EVSE_C and cipher suite C has been successful in TLS communication connections in the past. The combination of EVSE_D and cipher suite D has been successful in TLS communication connections in the past.

[0026] 1 again, the communication unit 13 includes various communication I / Fs. The communication unit 13 is controlled by the processor 11. The communication unit 13 is configured to be able to communicate with the EVSE 200. When external charging is performed between the communication unit 13 and the EVSE 200, the communication unit 13 exchanges various types of information in preparation for external charging. Details regarding the exchange of various types of information will be described later with reference to FIG. 4.

[0027] The HMI device 30 includes a display device such as a car navigation system. As shown in FIG. 3, the HMI device 30 can search for EVSEs 200 in the vicinity of the electric vehicle 100. On a screen on which the search result is displayed on the HMI device 30, an EVSE 200a that has a history of successful TLS communication connection in the past is displayed with, for example, a star-shaped mark 31. An EVSE 200b that has no history of TLS communication connection (i.e., an EVSE 200 other than the EVSE 200a) is displayed with, for example, a square mark 32. When a user selects any one of the EVSEs 200 on the screen shown in FIG. 3, the charging control ECU 10 (processor 11) determines that external charging is scheduled to be performed in the selected EVSE 200. The EVSE 200a and the EVSE 200b are examples of the "first power station" and the "second power station" of the present disclosure, respectively.

[0028] Here, when establishing TLS communication between an electric vehicle and an EVSE, the cipher suite used for the TLS communication may be specified on the electric vehicle side. A determination is made as to whether or not the specified cipher suite is applicable to the EVSE. If the specified cipher suite is incompatible with the EVSE, the TLS communication cannot be established. It is desirable to prevent the TLS communication connection between an electric vehicle and an EVSE from being unsuccessful.

[0029] Therefore, in this embodiment, the processor 11 of the charging control ECU 10 performs control to change the cipher suite and connect the TLS communication when the specified cipher suite is incompatible with the EVSE 200. As a result, when the changed cipher suite is compatible with the EVSE 200, a connection for TLS communication is established between the electrically powered vehicle 100 and the EVSE 200. Therefore, it is possible to prevent the connection for TLS communication between the electrically powered vehicle 100 and the EVSE 200 from being unsuccessful.

[0030] <Sequence control of electric vehicles and EVSE> Next, sequence control of external charging between electric vehicle 100 and EVSE 200 will be described with reference to Fig. 4. In the example shown in Fig. 4, it is assumed that electric vehicle 100 (charging control ECU 10) has already acquired information on whether or not TLS communication has been established with EVSE 200, which is to be the counterpart of external charging, by the search shown in Fig. 3 or the like.

[0031] In step S1, the connector 210 of the EVSE 200 is connected to an inlet (not shown) of the electric vehicle 100.

[0032] In step S2, the charging control ECU 10 determines whether the EVSE 200 connected via a connector to the electric vehicle 100 is the EVSE 200 making a connection for TLS communication for the first time (i.e., the EVSE 200 has no record of a connection for TLS communication). The charging control ECU 10 makes the determination in step S2 based on the information (information shown in FIG. 3) related to the above record stored in the memory 12. That is, the charging control ECU 10 determines that the EVSE 200 other than the EVSE 200a (see FIG. 3) whose information is stored in the memory 12 is the EVSE 200b (see FIG. 3) making a connection for TLS communication for the first time. If the EVSE 200 connected via a connector is the EVSE 200 (EVSE 200b) making a connection for TLS communication for the first time (Yes in S2), the process proceeds to step S3. If the EVSE 200 connected via a connector is the EVSE 200 (EVSE 200a) making a connection for TLS communication for the first time (No in S2), the process proceeds to step S4.

[0033] In step S3, the charging control ECU 10 preferentially designates (selects) a cipher suite with higher encryption strength among the cipher suites (A to D, see FIG. 2) available to the electric vehicle 100 as the cipher suite to be used for TLS communication. That is, the charging control ECU 10 designates (selects) a cipher suite with the highest encryption strength among the cipher suites (A to D) available to the electric vehicle 100. Information regarding the ranking of the encryption strengths of the cipher suites (A to D) is stored in, for example, the memory 12. Next, the process proceeds to step S5.

[0034] In step S4, the charging control ECU 10 preferentially specifies (selects) a cipher suite that has a proven track record in TLS communication connections as the cipher suite to be used in TLS communication. For example, when the electric vehicle 100 is connected to the EVSE_1 (see FIG. 2), cipher suite A is specified. Note that, when there are multiple cipher suites that have a proven track record in TLS communication connections, a cipher suite with higher encryption strength from among the multiple cipher suites that have a proven track record may be specified preferentially, or a cipher suite with a higher track record (a cipher suite that has been used more frequently in TLS communication connections) may be specified. Next, the process proceeds to step S5.

[0035] In step S5, the charging control ECU 10 starts a TLS communication connection with the EVSE 200. In step S6, the charging control ECU 10 transmits, through the communication unit 13 to the EVSE 200, information on the encryption suite specified in step S3 or S4.

[0036] In step S7, EVSE 200 determines whether the encryption suite transmitted from electric powered vehicle 100 in step S6 is compatible with EVSE 200. In step S8, electric powered vehicle 100 transmits the determination result (OK or NG) in step S7 to electric powered vehicle 100 (communication unit 13).

[0037] In step S9, the charging control ECU 10 determines whether the connection of the TLS communication has been successful. If the determination result of step S8 is OK, the charging control ECU 10 determines that the connection of the TLS communication has been successful. If the determination result of step S8 is NG (if an alert has been sent from the EVSE 200), the charging control ECU 10 determines that the connection of the TLS communication has failed. If the connection of the TLS communication has been successful (Yes in S9), the process proceeds to step S10. If the connection of the TLS communication has failed (No in S9), the process proceeds to step S12. Note that information on the combination of the cipher suite and the EVSE 200 with which the connection of the TLS communication has failed may be recorded in the memory 12.

[0038] In step S10, the charging control ECU 10 updates (stores) the record of the combination of the EVSE 200 and the cipher suite for which the TLS communication connection has been successful. If the above combination is the combination of the EVSE 200 and the cipher suite for which the TLS communication connection has been successful for the first time, the above combination is newly stored in the memory 12. If the above combination is the combination of the EVSE 200 and the cipher suite for which the TLS communication connection has been successful for the first time, the number of successes for the above combination may be updated. Next, the process proceeds to step S11.

[0039] In step S11, the charging control ECU 10 starts a PnC session with the EVSE 200.

[0040] In step S12, the charging control ECU 10 determines whether or not the charging control ECU 10 has tried to connect TLS communication using all cipher suites that can be used by the electric vehicle 100. If all cipher suites have been tried (Yes in S12), the process proceeds to step S13. If all cipher suites have not yet been tried (No in S12), the process proceeds to step S14.

[0041] In step S13, the charging control ECU 10 abandons the PnC connection and starts an EIM (External Identification Means) session. EIM means that a process such as billing is an external authentication method. Note that information about the EVSE 200 with which the EIM session is performed may be stored in the memory 12. Next, the process proceeds to step S17.

[0042] In step S14, the charging control ECU 10 switches the cipher suite to be used to another cipher suite. For example, the charging control ECU 10 may switch to a cipher suite with the highest encryption strength among cipher suites to which connection attempts are not being made. Furthermore, if the cipher suite with a proven track record remains among the cipher suites to which connection attempts are not being made, the charging control ECU 10 may switch to the cipher suite with a proven track record. Next, the process returns to step S5.

[0043] In step S15, EVSE 200 determines whether an EIM session has started. If an EIM session has started (Yes in S15), the process proceeds to step S17. If an EIM session has not started (No in S15), the process proceeds to step S16.

[0044] In step S16, EVSE 200 determines whether a PnC session has started. If a PnC session has started (Yes in S16), the process proceeds to step S17. If a PnC session has not started (No in S16), the process returns to step S7.

[0045] In step S17, billing authentication is performed between the charging control ECU 10 and the EVSE 200.

[0046] In step S18, charging (external charging) is started between the electric vehicle 100 and the EVSE 200. In step S19, external charging is ended. In step S20, the connection state between the connector 210 of the EVSE 200 and the electric vehicle 100 is released.

[0047] As described above, in this embodiment, when the cipher suite is incompatible with the EVSE 200 (when the TLS communication fails due to the incompatibility), the charging control ECU 10 (processor 11) performs control to change the cipher suite and connect the TLS communication. This makes it possible to resolve the cipher suite incompatibility even if the TLS communication connection fails due to the cipher suite incompatibility. As a result, it is possible to prevent charging between the electric vehicle 100 and the EVSE 200 from not being started.

[0048] Furthermore, in this embodiment, when connecting TLS communication between the EVSE 200 that has a track record of TLS communication and the electrically powered vehicle 100, the charging control ECU 10 (processor 11) preferentially specifies the cipher suite associated with the EVSE 200 in the information recorded in the memory 12 as the cipher suite to be used for the TLS communication. This makes it possible to switch the cipher suite to be used to a cipher suite that has a track record before starting the connection of the TLS communication between the electrically powered vehicle 100 and the EVSE 200. As a result, it is possible to shorten the time required for the process of connecting the TLS communication (the user's waiting time).

[0049] In the above embodiment, the charging control ECU 10 (processor 11) mounted on the electric vehicle 100 executes the process according to the above embodiment, but the present disclosure is not limited to this. For example, the process may be executed by a control device mounted on a server provided separately from the electric vehicle 100.

[0050] In the above embodiment, an example has been described in which the EVSE 200 determines the suitability of the encryption suite to be used and the electric vehicle 100 receives the determination result regarding the suitability, but the present disclosure is not limited to this. For example, the electric vehicle may obtain information on the encryption suite that is suitable for the EVSE from the EVSE or the like and perform the above-mentioned suitability determination.

[0051] In the above embodiment, an example has been described in which information regarding combinations of EVSE 200 that have been previously connected and cryptographic suites is recorded in memory 12 of electric vehicle 100, but the present disclosure is not limited to this. The information may be recorded in an external storage device (e.g., a server) or a cloud, and the electric vehicle may acquire the information from the storage device, the cloud, or the like.

[0052] In the above embodiment, an example is shown in which a cipher suite with high encryption strength is preferentially specified when connecting TLS communication to an EVSE 200 that has not previously been connected for encrypted communication, but the present disclosure is not limited to this. In the above TLS communication, a cipher suite may be specified randomly.

[0053] In the above embodiment, an example in which TLS communication is connected as the encrypted communication has been described, but the present disclosure is not limited to this. For example, SSL (Secure Socket Layer) communication may be connected as the encrypted communication.

[0054] In the above embodiment, an example has been described in which the process according to the above embodiment is executed when charging (external charging) from the EVSE 200 to the electric vehicle 100, but the present disclosure is not limited to this. The process may be executed when discharging (external discharging) from the electric vehicle 100 to the EVSE 200.

[0055] In the above embodiment, an example has been described in which information on the track record of TLS communication connection in the EVSE 200 is acquired when the EVSE 200 is searched for by the HMI device 30, but the present disclosure is not limited to this. For example, the electric vehicle 100 may acquire information on the track record of TLS communication connection in the EVSE 200 when the electric vehicle 100 is parked near the EVSE 200 or when the electric vehicle 100 is connected to the EVSE 200 via a connector, etc.

[0056] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present disclosure is defined by the claims, not by the description of the embodiments described above, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0057] 10 charging control ECU (control device), 11 processor, 12 memory, 13 communication unit (acquisition unit), 100 electric vehicle, 200 EVSE (power stand), 200a EVSE (first power stand), 200b EVSE (second power stand), 210 connector.

Claims

1. A control device that controls encrypted communication between an electric vehicle and a power station, a processor that performs control for specifying an encryption method and connecting the encrypted communication; an acquisition unit that acquires information regarding the suitability of the encryption method designated by the processor at the power station; The processor controls the control device to change the encryption method and connect the encrypted communication when the information indicates that the encryption method is incompatible with the power station.

2. the power stations include a first power station at which the encrypted communication connection has been successfully established in the past; 2. The control device according to claim 1, wherein when connecting the encrypted communication between the first power stand and the electric vehicle, the processor preferentially designates, as the encryption method to be used for the encrypted communication, the encryption method that has previously been used to successfully connect the encrypted communication at the first power stand.

3. the power stations include a second power station to which the encrypted communication has not been previously connected, 3. The control device according to claim 1, wherein when connecting the cryptographic communication between the second power station and the electric vehicle, the processor preferentially specifies the encryption method having a higher encryption strength in the cryptographic communication as the encryption method to be used for the cryptographic communication, rather than the encryption method having a lower encryption strength in the cryptographic communication.

4. 3. The control device according to claim 1, wherein the processor controls connection of the encrypted communication with the power stand in a PnC system in which billing authentication and charging are automatically performed in response to a connector of the power stand being connected to the electric vehicle.

5. A control method for controlling encrypted communication between an electric vehicle and a power station, comprising: a step of controlling connection of the encrypted communication by specifying an encryption method; acquiring information regarding suitability of the designated encryption method at the power station; The control method, wherein the step of controlling the connection includes a step of controlling the connection of the encrypted communication by changing the encryption method when the information indicates that the encryption method is incompatible with the power station.

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