Electric vehicles

Abstract

To accurately determine whether or not a connector is attached to an inlet.SOLUTION: An ECU executes processing comprising: a step (S100) of determining whether or not a current value of a value showing a state of a lid is a value showing an open state; a step (S102) of determining whether or not a previous value of the value showing the state of the lid is a value showing a closed state, when the current value is the value showing the open state (YES in S100); a step (S104) of executing offset learning processing, when the previous value is the value showing the closed state (YES in S102); and a step (S106) of considering the current value as the value of the previous value.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to electric vehicles.

Background Art

[0002] In electric vehicles having a motor as a drive source, such as electric cars and plug-in hybrid vehicles, charging using a power source outside the electric vehicle (hereinafter referred to as external charging) is performed on an in-vehicle power storage device that supplies power to the drive source. This external charging is performed, for example, by attaching (connecting) a connector connected to an external power source to an inlet provided in the electric vehicle. Therefore, it is required to accurately determine whether or not a connector is attached to the inlet.

[0003] Japanese Patent Application Laid-Open No. 2021-126009 (Patent Document 1) discloses a technique for determining the type of connector and whether or not a connector is attached to an inlet based on the potential of a signal given via the inlet when the connector is attached to the inlet.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] As mentioned above, when determining whether a connector is attached to an inlet based on the potential of the signal supplied via the inlet, a predetermined range of potentials and a threshold within that range are set. On the other hand, considering compatibility between the vehicle and the connector, a certain degree of error is required, such as errors in the resistance of the internal circuit or detection errors on the vehicle side. However, if the range of potentials that can be taken due to the allowed error exceeds the predetermined range, it may not be possible to set a threshold for determining whether a connector is attached to the inlet.

[0006] This disclosure was made to solve the above-mentioned problems, and its purpose is to provide an electric vehicle that can accurately determine whether or not a connector is attached to the inlet. [Means for solving the problem]

[0007] An electric vehicle according to one aspect of this disclosure includes an inlet covered by a lid and having a shape to which connectors for external equipment can be attached, a first detection circuit for detecting the open / closed state of the lid, a second detection circuit for outputting a voltage indicating whether or not a connector is attached to the inlet, and a control device for performing an offset learning process that calculates a correction value using the difference between the voltage output by the second detection circuit and a predetermined voltage when no connector is attached to the inlet. The control device performs the offset learning process using the detection result of the first detection circuit.

[0008] In this way, based on the state of the charging port lid, it is possible to reliably determine that the charging connector is not mated to the charging port. This allows for learning the voltage offset when the connector is not mated to the charging port at the appropriate timing (when the connector is not mated to the charging port and just before the connector is mated).

[0009] In one embodiment, the control device uses the detection result to perform an offset learning process when the lid changes from a closed state to an open state.

[0010] In this way, the moment the lid changes from a closed state to an open state, the connector is not yet mated, and there is a high probability that the connector is about to be mated, so it can be determined that this is a suitable timing for offset learning.

[0011] In one further embodiment, when the lid changes from a closed state to an open state, the control device performs an offset learning process using the detection result of the second detection circuit immediately preceding the change to the open state.

[0012] In this way, there is a non-zero possibility that the connector will be mated at the moment it opens from a closed state. Therefore, offset learning is performed using the mating signal voltage when the lid was closed, rather than the mating signal voltage at the moment the lid opens. This allows the offset to be calculated using the mating signal voltage before the connector is mated.

[0013] In one further embodiment, the electric vehicle further includes a locking mechanism controlled by a control device so that the connector can be fixed to the inlet. The control device performs an offset learning process when the lid is closed and the locking mechanism is switched from a locked state to an unlocked state.

[0014] In this way, when the lid is closed, it is almost certain that the charging connector is not mated, and when the lid is unlocked, there is a high probability that the charging lid will open and the charging connector will be mated, so it can be determined that this is a suitable time to perform offset learning.

[0015] An electric vehicle according to another aspect of the present disclosure includes an inlet having a shape to which a connector of an external device can be attached, a first detection circuit that detects the speed of the vehicle, a second detection circuit that outputs a voltage indicating whether or not a connector is attached to the inlet, and a control device that executes an offset learning process for calculating a correction value using a difference between the voltage output by the second detection circuit when the connector is not attached to the inlet and a predetermined voltage. The control device executes the offset learning process when it is determined that the speed of the vehicle is equal to or higher than a threshold value.

[0016] In this way, since the vehicle speed is constant or higher, that is, the vehicle is moving, it can be ensured that the connector is not fitted. Therefore, it can be determined that it is an appropriate timing to perform offset learning.

Advantages of the Invention

[0017] According to the present disclosure, it is possible to provide an electric vehicle that accurately determines whether or not a connector is attached to an inlet.

Brief Description of the Drawings

[0018] [Figure 1] It is a diagram showing an example of the configuration of a vehicle. [Figure 2] It is a diagram showing an example of the circuit configuration in a power supply facility and a vehicle. [Figure 3] It is a diagram for explaining the operation of an ECU. [Figure 4] It is a diagram for explaining an example of the operation of an ECU in a modification. [Figure 5] It is a diagram for explaining another example of the operation of an ECU in a modification. [Figure 6] It is a diagram for explaining still another example of the operation of an ECU in a modification.

Embodiments for Carrying Out the Invention

[0019] 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 denoted by the same reference numerals and their description will not be repeated.

[0020] Hereinafter, the configuration of an electric vehicle (hereinafter referred to as a vehicle) 2 according to the present embodiment will be described. FIG. 1 is a diagram showing an example of the configuration of the vehicle 2. The vehicle 2 includes an electric vehicle capable of exchanging power with external electrical equipment such as, for example, a plug-in hybrid vehicle and an electric vehicle. In FIG. 1, for example, a case where the vehicle 2 is parked in a parking space where the power supply facility 10 is installed is assumed.

[0021] As shown in FIG. 1, the vehicle 2 includes an ECU (Electronic Control Unit) 1, a vehicle speed sensor 9, an inlet 3, a power conversion device 204, a lid switch 5, a lock mechanism 6, a battery 214, an inverter 216, and a motor generator (MG) 218.

[0022] The motor generator 218 is constituted by, for example, one or a plurality of three-phase AC rotating electric machines. The motor generator 218 exchanges power with the inverter 216. For example, when the vehicle 2 is driven, the motor generator 218 applies a rotational force to the drive wheels 222 using the power supplied from the inverter 216. The drive wheels 222 rotate by the rotational force applied by the motor generator 218, and the vehicle 2 travels.

[0023] The inverter 216 converts power bidirectionally between the AC power of the motor generator 218 and the DC power of the battery 214 in accordance with a control signal from the ECU 1. Note that a converter for boosting and bucking may be provided between the inverter 216 and the battery 214.

[0024] The battery 214 is, for example, a rechargeable power storage element (energy storage device), and typically a secondary battery such as a nickel-metal hydride battery or a lithium-ion battery having a solid or liquid electrolyte is used. Alternatively, a large-capacity capacitor may be used instead of the battery 214.

[0025] The battery 214 is externally charged using power supplied from the power supply equipment 10. External charging includes AC charging, in which the AC power supplied from the power supply equipment 10, which is an external facility of the vehicle 2, is converted into DC power by the power converter 204 to charge the battery 214.

[0026] The inlet 3 is provided on the exterior of the vehicle 2 together with the lid 4 and has a shape to which a connector 8, described later, can be attached. The inlet 3 is configured to enable power transmission to and from external equipment. The inlet 3 is provided with AC connection sections 202a and 202b and communication sections 202c to 202e.

[0027] When connector 8 is attached to inlet 3, the AC connection part of connector 8 (see Figure 2) is electrically connected to the AC connection parts 202a and 202b of inlet 3, and the communication part of connector 8 is connected to the communication parts 202c to 202e of inlet 3.

[0028] The power converter 204 performs power conversion between the battery 214 and the inlet 3 in response to a control signal from the ECU 1.

[0029] The lid switch 5 outputs a signal to the ECU 1 indicating the open state when the lid is opened, and stops outputting the signal indicating the open state or outputs a signal indicating the closed state to the ECU 1 when the lid is closed. The vehicle speed sensor 9 detects the speed of the vehicle 2 and outputs a signal to the ECU 1 indicating the detected speed of the vehicle 2.

[0030] The locking mechanism 6 uses an actuator (not shown) or the like to restrict the removal or attachment of the connector 8 to the inlet 3 (locked state), or to release the restriction on the attachment or removal of the connector 8 (unlocked state). The locking mechanism 6 switches between one state and the other in response to a control signal from the ECU 1. For example, the locking mechanism 6 is switched to the unlocked state when the vehicle 2 is stopped, and to the locked state when the vehicle 2 is running or when the connector 8 is attached to the inlet 3. The ECU 1 stores information about the state of the actuator (information such as a value indicating whether the locking mechanism 6 is in the locked state or the unlocked state) in its memory.

[0031] The ECU1 incorporates a CPU (Central Processing Unit) 101 and memory (including, for example, ROM (Read Only Memory), RAM (Random Access Memory), etc.) 102. Based on information such as maps and programs stored in the memory 102 and information from various sensors (for example, a vehicle speed sensor 9 and a lid switch 5), it controls various devices (for example, a locking mechanism 6, etc.) so that the vehicle 2 reaches a desired state. The various controls performed by the ECU1 are not limited to software processing; it is also possible to construct and process them using dedicated hardware (electronic circuits). The history of information acquired from various sensors is stored in a memory or other storage device.

[0032] Furthermore, when a connector 8 is attached to the inlet 3, the ECU 1 performs communication processing to receive predetermined information from the equipment on the connector side (power supply equipment 10). The predetermined information includes, for example, information regarding the power that can be exchanged between the power supply equipment 10 and the battery 214 (such as the connector connection signal PISW, which will be described later).

[0033] The following describes the circuit configuration between the power supply equipment 10 and the vehicle 2, using Figure 2 as an example, where the connector 8 is attached to the inlet 3. Figure 2 is a diagram showing an example of the circuit configuration between the power supply equipment 10 and the vehicle 2.

[0034] The power supply equipment 10 includes power supply relays K1 and K2, a power supply control device 10a, and an oscillation circuit 10b. When power supply relays K1 and K2 are open, the power supply path is interrupted. When power supply relays K1 and K2 are closed, power can be supplied from the AC power source (not shown) of the power supply equipment 10 to the vehicle 2 via the connector 8 and inlet 3.

[0035] The oscillator circuit 10b outputs a pilot signal CPLT to the ECU1 via connector 8 and inlet 3. The pilot signal CPLT is manipulated in potential by the ECU1 and used as a signal to remotely control the power supply relays K1 and K2 from the ECU1.

[0036] The power supply control device 10a controls the power supply relays K1 and K2 based on the potential of the pilot signal CPLT. The pilot signal CPLT is also used as a signal to notify the ECU1 of the rated current during AC charging from the oscillation circuit 10b.

[0037] The power supply control device 10a includes a CPU and memory, etc. (neither of which are shown). The power supply control device 10a detects the potential of the pilot signal CPLT output by the oscillation circuit 10b and controls the operation of the oscillation circuit 10b based on the detected potential of the pilot signal CPLT.

[0038] When the connector 8 is not connected to the inlet 3, the power supply control device 10a controls the operation of the oscillator circuit 10b so that the battery is V0 (for example, +12V) and a non-oscillating pilot signal CPLT is output.

[0039] When a connector 8 is connected to an inlet 3, the power supply control device 10a controls the operation of an oscillation circuit 10b so as to output a pilot signal CPLT that oscillates at a specified frequency and duty cycle.

[0040] When the upper limit value of the potential of the pilot signal CPLT drops to V2 (<V1), the power supply control device 10a controls the power supply relays K1 and K2 to be in a closed state. Thereby, the power from the AC power supply is supplied to the inlet 3 via the connector 8. The upper limit value of the potential of the pilot signal CPLT drops to V2 when the switch S2 becomes conductive.

[0041] The connector 8 includes resistors R4, RC, and a switch S3. One end of the switch S3 is connected to a ground wire L3. The other end of the switch S3 is connected to one end of the resistor RC. The resistor R4 is connected in parallel to the switch S3. The other end of the resistor RC is connected to a signal line L2. The signal line L2 is electrically connected to the communication unit 202d when the connector 8 is attached to the inlet 3.

[0042] The switch S3 is interlocked with a push button (not shown) provided on the connector 8. When the push button is not pressed, the switch S3 is in a closed state. When the push button is pressed, the switch S3 is in an open state.

[0043] One end of a resistor R5 is connected to the communication unit 202d, and the other end of the resistor R5 is connected to a power supply Vsmp. The ECU1 is configured to be able to acquire the potential between the resistor R5 and the communication unit 202d. The resistors RC, R4, R5, the switch S3, and the power supply Vsmp constitute a connection detection circuit that detects the connection state between the connector 8 and the inlet 3.

[0044] When connector 8 is attached to inlet 3, a potential (voltage) signal V3, determined by the voltage of power supply Vsmp and the resistance value of resistor R5, is generated on signal line L2 as the connector connection signal PISW (hereinafter also simply referred to as "PISW"). When connector 8 is attached to inlet 3 and the push button is not operated, a potential (voltage) signal V4, determined by the voltage of power supply Vsmp and resistors R5 and RC, is generated on signal line L2 as PISW. When the push button is operated while connector 8 is attached to inlet 3, a potential (voltage) signal V5, determined by the voltage of power supply Vsmp and resistors R4, R5, and RC, is generated on signal line L2 as PISW.

[0045] Therefore, the ECU1 can detect the connection status between the connector 8 and the inlet 3 by acquiring the potential (voltage) of the PISW using a voltage sensor or the like.

[0046] If connector 8 is not attached to inlet 3, the potential of PISW will be V3. If connector 8 is attached to inlet 3, the potential of PISW will be V4 or V5 depending on the operation state of the push button.

[0047] In other words, ECU1 can determine whether connector 8 is attached to inlet 3 based on whether the potential of PISW is V3 or not. However, in order to determine whether the potential of PISW is one of V3 to V5, a certain range is set centered on each of the reference potentials V3, V4, and V5, and the determination of whether connector 8 is attached to inlet 3 is made based on whether the potential falls within one of these ranges.

[0048] In this case, the range is set considering, for example, the error in the resistance values ​​of various resistors provided in the connector 8 (e.g., resistor R4 and resistor RC), the error in the resistance value of the resistor provided on the vehicle 2 side (e.g., resistor R5), and the detection error on the vehicle 2 side. If the allowable range of these errors is set wide in an attempt to ensure market compatibility (i.e., to enable determination of whether or not the connector is installed even if several connectors used in the market are installed), the range of potentials for determining potential V3 will be set wide, and if it extends to the range for determining potentials V4 and V5, it may become difficult to determine whether the connector is installed.

[0049] For example, consider a case where the range of potentials used to determine potential V3 is set to allow an error of ±5% from the reference potential, as stipulated by standards to ensure compatibility. In this case, if the sum of the resistance error and the detection error exceeds ±5%, it may not be possible to accurately determine whether the connector is not installed. The same applies when determining potentials V4 and V5.

[0050] Therefore, in this embodiment, when the connector 8 is not attached to the inlet 3, the ECU1 performs an offset learning process that calculates a correction value using the difference between the voltage output from the connection detection circuit (potential of PISW) and a predetermined reference voltage (voltage corresponding to potential V3). More specifically, the ECU1 performs the offset learning process when the value indicated by the lid switch 5 changes from a value indicating the closed state of the lid 4 to a value indicating the open state.

[0051] In this way, the value indicated by PISW can be obtained with high accuracy by executing the offset learning process, so that the sum of the resistance error and the detection error can be kept within the range of the potential V3 used to determine the potential mentioned above. This makes it possible to determine with high accuracy whether or not the connector 8 is attached to the inlet 3.

[0052] The following describes the processes performed by the ECU1 of the vehicle 2 according to this embodiment, with reference to Figure 3. Figure 3 is a diagram illustrating an example of the operation of the ECU1.

[0053] In step 100 (hereinafter referred to as S), the ECU1 determines whether the current value of the voltage output by the lid switch 5 (hereinafter referred to as the current value of the lid switch 5) indicates the open state. For example, the lid switch 5 outputs a voltage value indicating the ON state when the lid 4 is open, and outputs a voltage value indicating the OFF state or stops outputting the voltage value when the lid 4 is closed. If it is determined that the current value indicates the open state (YES in S100), the process moves to S102.

[0054] In S102, ECU1 determines whether the previous value of the voltage output by the lid switch 5 (hereinafter referred to as the previous value of the lid switch 5) indicates a closed state. ECU1 retrieves the previous value from memory and determines whether the retrieved previous value indicates a closed state. If it is determined that the previous value indicates a closed state (YES in S102), the process moves to S104.

[0055] In S104, ECU1 performs offset learning processing. ECU1 detects the voltage of PISW and calculates the difference between the detected voltage and the reference voltage as the correction value (learned value) α. The process then moves to S106.

[0056] In S106, ECU1 sets the current value of lid switch 5 as the previous value. The process then ends. If it is determined that the current value does not indicate the open state (NO in S100) or that the previous value does not indicate the closed state (NO in S102), the process moves to S106.

[0057] An example of the operation of ECU1 based on the structure and flowchart described above will now be explained. In the callout in Figure 3, a timing chart is shown with time on the horizontal axis and various voltages on the vertical axis. LN1 in Figure 3 shows the change in the voltage of PISW. LN2 in Figure 3 shows the change in the voltage output by lid switch 5.

[0058] If connector 8 is not installed, the voltage of PISW will be V(0), as shown in LN1 in Figure 3. The voltage V(0) is assumed to be lower than the reference voltage (potential V3) due to resistance errors, detection errors, etc. If the operation to open lid 4 is not performed, lid 4 will be in the closed state. If the closed state of lid 4 is maintained (NO in S100), the current value and the previous value of lid switch 5 will be the same (S106).

[0059] On the other hand, at time T(0), when the user opens the lid 4 to attach the connector 8 to the inlet 3, the voltage value of the lid switch 5 changes to a value indicating the open state (YES in S100). At this time, since the previous value indicates the closed state (YES in S102), the offset learning process is executed (S104). When the offset learning process is executed, a correction value α is calculated from the difference between the detected voltage of the PISW at time T(0) and the reference voltage. Then, the current value of the voltage value output by the lid switch 5 is set as the previous value (S106). After that, the ECU1 acquires the value obtained by adding the correction value α to the detected voltage as the PISW. As a result, the PISW acquired by the ECU1 will match the reference voltage, as shown in LN1 in Figure 3.

[0060] As described above, with the electric vehicle according to this embodiment, the value indicated by PISW can be obtained with high accuracy by executing the offset learning process, so that the sum of the resistance error and the detection error can be kept within the range of the potential V3 used to determine the potential described above. Therefore, it is possible to provide an electric vehicle that can accurately determine whether or not a connector is attached to the inlet.

[0061] The following describes variations. In the above-described embodiment, offset learning was performed using the current value of PISW detected when the lid 4 changed from an open state to a closed state. However, for example, offset learning may be performed using the previous value of PISW.

[0062] Figure 4 is a diagram illustrating an example of the operation of ECU1 in a modified example. Note that the processes S100, S102, and S106 shown in the flowchart of Figure 4 are the same as those shown in the flowchart of Figure 3, except as described below. Therefore, a detailed explanation will not be repeated.

[0063] If the previous value of lid switch 5 is determined to be a value indicating the closed state (YES in S102), the process moves to S200.

[0064] In S200, ECU1 performs offset learning. More specifically, ECU1 obtains the previous detected value of PISW when connector 8 is not installed, and calculates the difference between this value and the reference voltage (potential V3) corresponding to the uninstalled state. ECU1 calculates a correction value using the calculated difference. ECU1 calculates the correction value so that the sum of the previous value and the correction value equals the reference voltage. ECU1 calculates the correction value (learned value) by subtracting the previous value from the reference voltage. Furthermore, ECU1 obtains the current value of PISW by adding the correction value to the detected voltage of PISW. The process then moves to S106. After the processing in S106, the process moves to S202.

[0065] In S202, ECU1 sets the current value of PISW as the previous value of PISW. After that, the process is terminated.

[0066] An example of the operation of ECU1 in a modified version based on the flowchart described above will be explained. In the callout in Figure 4, a timing chart is shown with time on the horizontal axis and various voltages on the vertical axis. LN3 in Figure 4 shows the change in the current value of PISW. LN4 in Figure 6 shows the change in the previous value of PISW. LN5 in Figure 6 shows the change in the state of lid switch 5 (open / closed state of the lid).

[0067] If connector 8 is not installed, the voltage becomes V(0) as shown in LN3 and LN4 in Figure 6. If the operation to open lid 4 is not performed, lid 4 remains closed. If the closed state of lid 4 is maintained (NO in S100), the current value and previous value of lid switch 5 become the same (S106), and the current value and previous value of PISW become the same (S202).

[0068] On the other hand, at time T(1), when the user opens lid 4, the voltage value of lid switch 5 changes to a value indicating the open state (YES in S100). At this time, since the previous value indicates the closed state (YES in S102), the offset learning process is executed (S200). When the offset learning process is executed, a correction value β is calculated from the difference between the previous value of PISW at time T(1) and the reference voltage (potential V3). Then, the current value of lid switch 5 is set as the previous value (S106). After that, ECU1 obtains the value obtained by adding the correction value β to the detected value of PISW as the current value of PISW. As a result, as shown in LN3 in Figure 6, at time T(1), the potential of PISW changes to the corrected value. Then, as shown in LN4 in Figure 6, at time T(2), the previous value for the next calculation changes to the corrected value (reference voltage).

[0069] In this way, even if the current value of PISW changes immediately from the potential when connector 8 is not connected, such as when connector 8 is connected immediately after lid 4 is opened, it is possible to determine with high accuracy whether or not connector 8 is connected.

[0070] Furthermore, although the above-described embodiment was explained as determining whether or not to perform the offset learning process using the open / closed state of the lid 4, for example, the state of the locking mechanism 6 in addition to the open / closed state of the lid 4 may also be used to determine whether or not to perform the offset learning process. Figure 5 is a diagram illustrating another example of the operation of the ECU1 in a modified example.

[0071] In S300, ECU1 determines whether the current value of the value indicating the state of the lock mechanism 6 (hereinafter referred to as the current value of the lock mechanism 6) is a value indicating the unlocked state. If it is determined that the current value of the lock mechanism 6 is a value indicating the unlocked state (YES in S300), the process moves to S302.

[0072] In S302, ECU1 determines whether the current value of locking mechanism 6 indicates a locked state. If it is determined that the current value of locking mechanism 6 indicates a locked state (YES in S302), the process moves to S304.

[0073] In S304, ECU1 determines whether the current value of lid switch 5 indicates the closed state. If it is determined that the current value of lid switch 5 indicates the closed state (YES in S304), the process moves to S306.

[0074] In S306, ECU1 performs offset learning processing. This offset learning processing is the same as the processing in S106 in Figure 3. The process then moves to S308.

[0075] In S308, ECU1 sets the current value of lock mechanism 6 as the previous value. The process then ends. However, if it is determined that the current value of lock mechanism 6 does not indicate the unlocked state (NO in S300), or if it is determined that the previous value of lock mechanism 6 does not indicate the locked state (NO in S302), or if it is determined that the current value of lid switch 5 does not indicate the open state (NO in S304), the process moves to S308.

[0076] Another example of the operation of ECU1 in a modified example based on the flowchart described above will be explained. In the callout in Figure 5, a timing chart is shown with time on the horizontal axis and various voltages on the vertical axis. LN6 in Figure 5 shows the change in PISW. LN7 in Figure 5 shows the change in the state of lock mechanism 6. LN8 in Figure 5 shows the change in the state of lid switch 5 (open / closed state of lid 4).

[0077] If connector 8 is not installed, the voltage becomes V(0) as shown in LN6 in Figure 5. If the operation to open lid 4 is not performed, the closed state of lid 4 is maintained (NO in S300), and the locking mechanism 6 is also in the locked state (NO in S300), so the current value of locking mechanism 6 is the same as the previous value (S308).

[0078] Meanwhile, at time T(3), the lock mechanism 6 is switched to the unlocked state, and the current value of the lock mechanism 6 becomes the value indicating the unlocked state (YES in S300), and the previous value becomes the value indicating the locked state (YES in S302). As the open / closed state of the lid 4 becomes the closed state (YES in S304), the offset learning process is executed (S306). When the offset learning process is executed, a correction value α is calculated from the difference between the detected value of PISW at time T(3) and the reference voltage. Subsequently, when the ECU1 acquires the value of PISW, it acquires the value obtained by adding the correction value α to the detected value of PISW as the current value of PISW. As a result, the value of PISW acquired by the ECU1 matches the reference voltage, as shown in LN6 of Figure 5. Subsequently, the current value of the lock mechanism 6 is set as the previous value (S308). At time T(4), when the lid 4 is in the open state, the value indicating the open / closed state of the lid switch 5 changes to the value indicating the open state, as shown in LN8 of Figure 5.

[0079] In this way, when the locking mechanism 6 changes from the locked state to the unlocked state, the connector 8 is not mated to the inlet 3, so the PISW value can be obtained with high accuracy by performing the offset learning process.

[0080] Furthermore, although the above-described embodiment was explained as determining whether or not to perform the offset learning process using the open / closed state of the lid 4, for example, the open / closed state of the lid 4 may be predicted using the speed of the vehicle 2 to determine whether or not to perform the offset learning process. Figure 6 is a diagram illustrating yet another example of the operation of the ECU1 in a modified example.

[0081] In S400, ECU1 determines whether the vehicle speed is greater than or equal to the threshold Va. The threshold Va is a predetermined value, for example, used to determine whether vehicle 2 is moving or not. To prevent misjudgments, the threshold Va may also be the lower limit of the speed range in which vehicle 2 can be determined to be moving with a high degree of certainty. If it is determined that the vehicle speed is greater than or equal to the threshold Va (YES in S400), the process moves to S402.

[0082] In S400, ECU1 performs offset learning processing. The offset learning processing is the same as the method described in processing S106 in Figure 3 of the above embodiment. After that, the processing is terminated. Note that if it is determined that the vehicle speed is lower than the threshold (NO in S400), this processing is terminated.

[0083] Another example of the operation of ECU1 in a modified version based on the flowchart described above will be explained. In the callout in Figure 6, a timing chart is shown with time on the horizontal axis and voltage and vehicle speed on the vertical axis. LN9 in Figure 6 shows the change in PISW. LN10 in Figure 6 shows the change in vehicle speed. If connector 8 is not installed, the voltage becomes V(0) as shown in LN9 in Figure 6. If the operation to open lid 4 is not performed, the closed state of lid 4 is maintained. If the vehicle speed is lower than the threshold Va (NO in S400), the offset learning process is not performed.

[0084] On the other hand, as the vehicle speed increases and exceeds the threshold Va at time T(5) (YES in S400), the offset learning process is executed (S402). When the offset learning process is executed, a correction value α is calculated from the difference between the detected value of PISW and the reference voltage at time T(5). Subsequently, when ECU1 acquires the value of PISW, it acquires the value obtained by adding the correction value α to the detected value of PISW as the current value of PISW. As a result, as shown in LN9 in Figure 6, the value of PISW acquired by ECU1 will match the reference voltage.

[0085] In this way, the offset learning process is executed when the vehicle speed is above the threshold Va and connector 8 is not installed, so the PISW value can be obtained with high accuracy.

[0086] Furthermore, the above-mentioned modifications may be implemented by combining all or part of them as appropriate. The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the present invention is indicated by the claims rather than by the foregoing description, and all modifications within the meaning and scope equivalent to the claims are intended to be included. [Explanation of Symbols]

[0087] 1 ECU, 2 Vehicle, 3 Inlet, 4 Lid, 5 Lid switch, 6 Locking mechanism, 8 Connector, 9 Vehicle speed sensor, 10 Power supply equipment, 10a Power supply control device, 10b Oscillator circuit, 102 Memory, 202a, 202b Connection part, 202c, 202d, 202e Communication part, 204 Power converter, 214 Battery, 216 Inverter, 218 Motor generator, 222 Drive wheel.

Claims

1. An inlet covered with a lid and having a shape that allows for the attachment of connectors for external equipment, A first detection circuit for detecting the open / closed state of the lid, A second detection circuit that outputs a voltage indicating whether or not the connector is attached to the inlet, The system includes a control device that performs an offset learning process to calculate a correction value using the difference between the voltage output by the second detection circuit and a predetermined voltage when the connector is not attached to the inlet, The control device is an electric vehicle that performs the offset learning process using the detection result of the first detection circuit.

2. The electric vehicle according to claim 1, wherein the control device executes the offset learning process when the lid changes from a closed state to an open state using the detection result.

3. The electric vehicle according to claim 2, wherein the control device performs the offset learning process using the detection result of the second detection circuit immediately prior to the change to the open state when the lid changes from the closed state to the open state.

4. The electric vehicle further comprises a locking mechanism controlled by the control device so that the connector can be fixed to the inlet, The electric vehicle according to claim 1, wherein the control device executes the offset learning process when the lid is in a closed state and the locking mechanism is switched from a locked state to an unlocked state.

5. An inlet having a shape that allows connectors for external equipment to be attached, A first detection circuit for detecting the vehicle's speed, A second detection circuit that outputs a voltage indicating whether or not the connector is attached to the inlet, The system includes a control device that performs an offset learning process to calculate a correction value using the difference between the voltage output by the second detection circuit and a predetermined voltage when the connector is not attached to the inlet, The control device is an electric vehicle that executes the offset learning process when it is determined that the vehicle's speed is above a threshold.

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