Charging Control Method and Charging Control Device

Abstract

To provide a charge control method and a charge control device capable of suppressing an increase in a charging waiting time when the remaining charged amount of a driving battery is equal to or less than a predetermined threshold.SOLUTION: A charge control method comprises: setting first charging threshold at which a driving battery needs to be charged and a second charging threshold in which a remaining charged amount is greater than the first charging threshold; detecting and comparing the remaining charged amount with the first charging threshold and the second charging; and outputting a charging instruction to perform charge when the remaining charged amount is smaller than the second charging threshold and greater than the first charging threshold and when there is a charging spot with a predicted charging waiting time smaller than a predetermined value.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present invention relates to a charging control method and a charging control device for a vehicle that requires charging of a driving battery, such as an electric vehicle or a hybrid vehicle.

Background Art

[0002] When the remaining charge of an electric vehicle is equal to or less than a predetermined threshold, a vehicle information providing device is known that calculates a range in which the vehicle can travel based on the current remaining charge and presents the positions of charging spots existing within the travelable range (see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the above-described conventional vehicle information providing device, even when the remaining charge is equal to or less than a predetermined threshold, depending on the congestion situation of the charging spot, such as during a time period when the charging spot is congested or at a location where access is concentrated, there is a problem that the charging waiting time becomes long.

[0005] The problem to be solved by the present invention is to provide a charging control method and a charging control device that can suppress an increase in the charging waiting time when the remaining charge of the driving battery is equal to or less than a predetermined threshold.

Means for Solving the Problems

[0006] The present invention sets a first charge threshold value at which charging of the battery for driving is required and a second charge threshold value at which the remaining charge amount is greater than the first charge threshold value, detects the remaining charge amount, compares it with the first charge threshold value and the second charge threshold value, and when the remaining charge amount is less than the second charge threshold value and greater than the first charge threshold value, if there is a charging spot where the predicted value of the charging waiting time is less than a predetermined value, a charging instruction to perform charging is output to solve the above problem.

Effect of the Invention

[0007] According to the present invention, when the remaining charge amount of the battery for driving is equal to or less than a predetermined threshold value, it is possible to suppress the increase in the charging waiting time.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5A

Figure 5B

Figure 6

Figure 7

Figure 8

Embodiment for Carrying out the Invention

[0009] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The charging control method and apparatus 1 of the present embodiment predicts the transition of the state of charge (SOC) of the battery from the vehicle information of the vehicle V stored in the vehicle database, and the driving battery (a secondary battery that supplies power to the driving motor of an electric vehicle or a hybrid vehicle. Hereinafter, also simply referred to as a battery.) sets a first charging threshold value for preventing a so-called power shortage state, and a second charging threshold value larger than the first charging threshold value. Then, from the facility information of the charging spot (charger outside the vehicle) stored in the charging spot database, a predicted value of the charging waiting time is calculated, and when the SOC of the battery is smaller than the second charging threshold value and larger than the first charging threshold value, a charging instruction is output when there is a charging spot where the predicted value of the charging waiting time is smaller than a predetermined value.

[0010] FIG. 1 is a block diagram showing an outline of a charging control system S using the charging control apparatus 1 according to an embodiment of the present invention. The charging control apparatus 1 of the present embodiment is also an embodiment for implementing the charging control method according to the present invention. The charging control apparatus 1 includes a communication unit 13, the charger 2 includes a communication unit 23, the in-vehicle control apparatus 3 includes a communication unit 33, and information can be transmitted and received to and from each other via a telecommunication line network NW such as the Internet. Note that the communication path may be wired or wireless.

[0011] The charger 2 is connected between the battery mounted on the vehicle V and the commercial power supply provided at the charging spot C, converts the voltage input from the commercial power supply into a voltage suitable for charging the battery, and supplies power to the battery using the converted voltage as the charging voltage. In the present embodiment, an example in which one charger 2 having one charging port is connected to the commercial power supply is applied as the charging spot C for description, but the form of the charging spot C may be, for example, a plurality of chargers 2 having a plurality of charging ports connected to the commercial power supply.

[0012] The charger 2 includes a control unit 21 that executes control processing for charging the battery, a sensor 22 that is electrically connected to the battery, and a communication unit 23 that communicates with an external device such as the charge control device 1 or the in-vehicle control device 3.

[0013] The control unit 21 includes a charge control function for controlling the charging of the battery mounted on the vehicle V, and a charge time calculation function for calculating the charging time of the battery. Specifically, when the charger 2 and the vehicle V are electrically connected via a plug or the like of the power supply connector, the control unit 21 acquires the measured value of the SOC, the detected values of the voltage, current, temperature, etc. of the battery from the in-vehicle control device 3 by the charge control function, and controls the charging power to the battery output from the charger 2.

[0014] In addition, the control unit 21 switches the charging mode according to the chargeable capacity of the battery and the outputtable power of the charger 2. The chargeable capacity is the maximum input power that can be input from the charger 2 to the battery during charging of the battery, and the outputtable power is the maximum output power that can be output from the charger 2. There are a rapid charger with a high outputtable power and a normal charger with a lower outputtable power than the rapid charger in the charger 2, and the charging mode is selected according to the chargeable capacity of the battery. The control unit 21 calculates the charging time of the battery (the time from the start to the completion of charging) and the remaining charging time of the battery (the remaining time until the completion of charging) according to the charging mode by the charge time calculation function, and outputs them to the charge control device 1 and the in-vehicle control device 3 via the communication unit 23.

[0015] The sensor 22 is, for example, a plug or the like provided on the power supply connector of the charger 2, and also serves as the communication unit 23 in this embodiment. When the plug of the charger 2 is inserted into the charging port of the vehicle V, the charger 2 and the battery are electrically connected. When the charger 2 is electrically connected to the battery, the plug as the sensor 22 and the communication unit 23 transmits the operation information of the charger 2 to the vehicle V, receives charging information such as a charging permission signal and a charging command value from the vehicle V, and outputs this to the control unit 21.

[0016] Each time the battery is charged, sensor 22 transmits the usage information of charger 2 to charging spot database 12 via communication unit 23. The usage information of charger 2 includes information such as the date and time when charger 2 was used, the charging time, the charging capacity, whether different vehicles charged continuously, and the identification information of the vehicle that was charged.

[0017] In-vehicle control device 3 includes a control unit 31 that executes control processing for charging the battery, a charge capacity detection unit 32 that detects the state of charge (SOC) of the battery, a communication unit 33 that communicates with external devices such as charge control device 1 or charger 2, and a display unit 34 for notifying the driver of vehicle V of information. The battery mounted on vehicle V is a battery configured by connecting a plurality of secondary batteries such as, for example, a lithium-ion secondary battery or a nickel-metal hydride secondary battery.

[0018] Control unit 31 transmits the information on the current SOC of the battery, acquired using charge capacity detection unit 32, to charge control device 1 and charger 2 via communication unit 33. The information on the current SOC of the battery is used when charge control device 1 formulates a charging plan or when charger 2 executes charging. Further, control unit 31 uses a position detection device such as a GPS (Global Positioning System) receiver (not shown) provided in in-vehicle control device 3 to acquire the current position information of vehicle V, and transmits the acquired current position information to charge control device 1 via communication unit 33. This current position information of vehicle V is used to specify a reference position when charge control device 1 formulates a charging plan.

[0019] Furthermore, the control unit 31 notifies the driver of the vehicle V of the charging command received from the charging control device 1 and the operation information received from the charger 2 by using a display unit 34 such as a display. The display unit 34 is, for example, a display device such as a display of a navigation device or a display provided on an instrument panel. When the control unit 31 receives the position information of the charging spot C where charging is to be executed together with the charging command from the charging control device 1, the control unit 31 can present guidance information of the charging spot C to the driver of the vehicle V by superimposing the charging spot C on a map image and displaying it on the display unit 34. Also, when the control unit 31 receives operation information from the charger 2, the control unit 31 can present the time required for charging to the driver of the vehicle V by displaying the remaining charging time of the battery calculated by the charger 2 on the display unit 34.

[0020] Also, the control unit 31 of the present embodiment has an autonomous driving control function of the vehicle V. The autonomous driving control function is a function for the control unit 31 to autonomously control the driving of the host vehicle without depending on the driver's operation. The autonomous driving control function of the control unit 31 includes an autonomous speed control function for autonomously controlling the driving speed of the host vehicle and an autonomous steering control function for autonomously controlling the steering of the host vehicle. Autonomously controlling without depending on the driver's operation also includes performing some operations by the driver. Note that the autonomous driving control function of the control unit 31 is not an essential configuration of the present invention, and all operations may be performed by the driver as needed.

[0021] The charge capacity detection unit 32 calculates the current SOC of the battery at predetermined time intervals and outputs the calculation result to the control unit 31. For example, the SOC of the battery is calculated based on detection values of a current sensor, a voltage sensor, a temperature sensor, etc. (not shown) provided in the in-vehicle control device 3. When the battery is electrically connected to the charger 2 and charging is being executed, the SOC during charging is calculated by integrating the charging current of the battery using the current sensor. When the charge capacity detection unit 32 detects that the current SOC of the battery has reached the target SOC (for example, 100%), the control unit 31 transmits a command to stop the output from the charger 2 to the battery via the communication unit 33 and ends the charging of the battery.

[0022] The charging control device 1 includes a vehicle database 11 that stores vehicle information such as the driving distance of the vehicle V stored in association with the identification information of the vehicle, the charging history information, and the transition of the SOC, a charging spot database 12 that stores facility information such as the facility information of the charging spot C, the usage information, and the charging waiting time calculated from the usage status of the charger 2, a communication unit 13 that can communicate with the charger 2 or the in-vehicle control device 3, and a control unit 14 that executes charging control processing. In this embodiment, the vehicle database 11 and the charging spot database 12 are configured to be included in the charging control device 1. However, for example, they may be provided in an external server or the like and configured to be accessible via an Internet line or the like.

[0023] The vehicle database 11 stores and periodically updates the vehicle information of the vehicle V received from the in-vehicle control device 3 via the communication unit 13. The vehicle information includes identification information such as the vehicle number, vehicle body number, and vehicle type of the vehicle V, charging history such as the rated capacity of the battery, chargeable capacity, charging frequency, and charging location, and information such as the driving distance of the vehicle V stored in association with the transition of the SOC. In addition to these, the vehicle information may include the position information of the vehicle V, the traveling direction, the vehicle speed, the ON / OFF state of the door lock, the opening / closing state of the door, the seat belt sensor value, and whether or not it is in autonomous driving. These vehicle information are used when the charging planning unit 141 formulates a charging plan.

[0024] The charging spot database 12 stores and periodically updates the facility information of the charging spot C received from the charger 2 via the communication unit 13. The facility information includes the position information (latitude and longitude) of the charging spot C, equipment information such as the type, number, and output power of the charger 2, usage information such as the operation rate of the charging spot C, full / empty information, congestion time zone, date and time when the charger 2 was used, charging time, charging capacity, whether different vehicles charged continuously, and the identification information of the charged vehicles. In addition to these, the facility information includes information such as the charging waiting time calculated from the usage status of the charger 2. The charging waiting time will be described later.

[0025] The communication unit 13 communicates with external devices such as the charger 2 or the in-vehicle control device 3 via the telecommunication line network NW. The control unit 14 acquires the current usage status of the charging spot C from the charger 2 via the communication unit 13, and acquires the current SOC of the battery from the in-vehicle control device 3 and reflects it in the charging plan. Further, the charging command from the charging control device 1 is transmitted to the in-vehicle control device 3 via the communication unit 13.

[0026] The control unit 14 includes a ROM (Read Only Memory) in which a program for executing the charging control process by the charging control device 1 is stored, and a CPU (Central Processing Unit) that functions as an operation circuit for functioning as the charging control device 1 by executing the program stored in this ROM, and a RAM (Random Access Memory) that functions as an accessible storage device. Note that as the operation circuit, an MPU (Micro Processing Unit), a DSP (Digital Signal Processor), an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), etc. can be used instead of or together with the CPU. The charging plan unit 141, the charging plan correction unit 142, the prediction error correction unit 143, the power outage prevention determination unit 144, and the charging timing determination unit 145 of the control unit 14 realize various functions such as a charging plan function, a prediction error correction function, a power outage prevention function, and a charging timing determination function as the charging control device 1 by executing the program stored in the ROM.

[0027] The charging plan unit 141 formulates a charging plan for the vehicle V based on the vehicle information of the vehicle V obtained from the vehicle database 11 and the facility information of the charging spot C obtained from the charging spot database 12. As described above, the vehicle information of the vehicle V includes information such as the rated capacity of the battery, the chargeable capacity, the charging frequency, the charging history such as the charging location, and the driving distance of the vehicle V stored in association with the transition of the SOC. In addition, the facility information of the charging spot C includes usage information such as the date, time, charging time, charging capacity, whether different vehicles have charged continuously, and the identification information of the charged vehicle, as well as information such as the predicted charging waiting time calculated from the usage status of the charger 2. The charging plan unit 141 calculates the predicted transition of the SOC of the battery and the predicted value of the charging waiting time of the charging spot C from these pieces of information. Then, based on this calculation result, a charging plan for the vehicle V is formulated and output to the charging timing determination unit 145.

[0028] Figure 2 is a graph showing an example of the predicted transition of the SOC of the battery and the predicted value of the charging waiting time of the charging spot. The dashed-dotted line graph shows the predicted transition of the SOC (remaining charge) of the battery with respect to the elapsed time, and the solid line graph shows the transition of the predicted value of the charging waiting time at the charging spot C with respect to the elapsed time. First, the charging plan unit 141 sets a predetermined SOC at which the battery needs to be charged as the first charging threshold. The predetermined SOC at which the battery needs to be charged is a value for preventing the vehicle V from being in a so-called power-off state (SOC 0%), and is not particularly limited. For example, it can be a value such as SOC 20%, which allows the vehicle V to travel a certain distance before reaching the power-off state. The first charging threshold may be set to any value, or may be calculated and set, for example, from the driving distance of the vehicle V stored in association with the transition of the SOC obtained from the vehicle database 11.

[0029] Next, the charging plan unit 141 sets a predetermined SOC greater than the first charging threshold as the second charging threshold. The predetermined SOC greater than the first charging threshold is not particularly limited. For example, it could be SOC 35%. It is a value that allows the vehicle V to travel a certain distance before reaching the first charging threshold. The second charging threshold may be set to any value. For example, when applying the present invention to commercial vehicles such as a ride-hailing service using driverless taxis, the charging amount consumed in one ride-hailing service (picking up passengers, transporting to the destination, and returning to the waiting station) is calculated, and the charging amount consumed in the ride-hailing service is added to the first charging threshold to obtain the second charging threshold. Specifically, if it is calculated from the vehicle information of vehicle V obtained from the vehicle database 11 that the charging amount consumed in one ride-hailing service is SOC 10%, then for the first charging threshold of SOC 20%, SOC 40% obtained by adding the charging amount of SOC 20% consumed in two ride-hailing services is set as the second charging threshold. The reason for adding the charging amount consumed in two ride-hailing services is that if the first charging threshold is reached at the end of one ride-hailing service, the frequency of sending the charging command will increase, which may reduce the charging efficiency.

[0030] When the first charging threshold and the second charging threshold are set based on the predicted transition of the SOC, the charging plan unit 141 calculates the predicted time t1 when the SOC of the battery reaches the second charging threshold and the predicted time t5 when the SOC of the battery reaches the first charging threshold using the vehicle information of vehicle V obtained from the vehicle database 11. Then, the predicted time t1 when the SOC of the battery reaches the second charging threshold is set as the start time of charging consideration, and the predicted time t5 when the SOC of the battery reaches the first charging threshold is set as the end time of charging consideration.

[0031] Next, the charging plan unit 141 calculates the travel position information of the vehicle V from the current position information of the vehicle V acquired from the in-vehicle control device 3, the travel route information set for the vehicle V, etc., from the charging consideration start time t1 to the charging consideration end time t5. Then, it searches the charging spot database 12, detects the charging spot C within the range that can be traveled from the travel position of the vehicle V, and specifies it as the target charging spot C for calculating the predicted value of the charging waiting time. For the specified charging spot C, the charging plan unit 141 calculates the predicted value of the charging waiting time from the charging consideration start time t1 to the charging consideration end time t5.

[0032] Figure 3 shows an example of a scene for calculating the predicted value of the charging waiting time based on the data of the past charging waiting time of the charging spot C. In the figure (A), it shows an example of the charging waiting time calculated from the past usage status of the charger 2 stored in the charging spot database 12 and the predicted value of the charging waiting time calculated based on these charging waiting times. In the figure (B), it is a diagram for explaining the calculation process of the charging waiting time at 9:00. For example, when the charging consideration start time t1 is 9:00, the charging plan unit 141 searches the data of the past charging waiting time at 9:00 stored in the charging spot database 12, calculates the average value from the sum of the past charging waiting times, and uses this as the predicted value of the charging waiting time.

[0033] Figure 3(B) shows a scene where the charging waiting time at charging spot C at 9:00 is calculated based on the past usage status of charger 2. It is assumed that the time required for one charge using charger 2 is 30 minutes. On March 1, 2021, there is a vehicle that started charging at 8:45 using charger 2, so the charging waiting time at 9:00 is 15 minutes. Similarly, on March 2, 2021, there is a vehicle that started charging at 8:50, so the charging waiting time is 20 minutes. In contrast, on March 3, 2021, there is no vehicle charging using charger 2, so the charging waiting time is 0 minutes. On March 4, 2021, there is a vehicle that started charging at 8:45 and a vehicle that started charging continuously at 9:15 after the previous vehicle finished charging, so the charging waiting time is 45 minutes. Thus, the charging waiting time can be calculated from the past usage status of charger 2. Note that other known methods may be used as the method for calculating the charging waiting time.

[0034] The charging plan unit 141 calculates a predicted value of the charging waiting time from the charging waiting time calculated from the past usage status of charger 2. For example, regarding the predicted value of the charging waiting time at 9:00, as shown in Figure 3(A), when the charging waiting times of 15 minutes on March 1, 2021, 20 minutes on March 2, 2021, 0 minutes on March 3, 2021, and 45 minutes on March 4, 2021 are retrieved respectively, the charging plan unit 141 sets 20 minutes, which is the average time of the charging waiting times from March 1, 2021 to March 4, 2021, as the predicted value of the charging waiting time. Note that the predicted value of the charging waiting time may be the average value of the past charging waiting times, may be the median value, or other known methods can also be used. Thus, by using the data of the past usage status of charging spot C stored in the charging spot database 12, an appropriate predicted value of the charging waiting time based on the measured values can be calculated.

[0035] Returning to FIG. 2, when the charging plan unit 141 calculates the predicted value of the waiting time for charging, it calculates the time when the predicted value of the waiting time for charging becomes smaller than a predetermined value from the start time t1 of charging consideration to the end time t5 of charging consideration. The predetermined value is not particularly limited. For example, it may be set to 30 minutes, which is the usage time of the charger 2 for one time. Alternatively, based on the vehicle information of the vehicle V obtained from the vehicle database 11, the estimated time from the second charging threshold value to the first charging threshold value of the battery's SOC may be calculated and set.

[0036] As shown in FIG. 2, from the start time t1 of charging consideration to time t2, and from time t3 to the end time t5 of charging consideration, the predicted value of the waiting time for charging is smaller than the predetermined value (here, 30 minutes). On the other hand, from time t2 to time t3, the predicted value of the waiting time for charging is larger than the predetermined value. Therefore, the charging plan unit 141 outputs a charging instruction to execute charging from the start time t1 of charging consideration to time t2 and from time t3 to the end time t5 of charging consideration. In this way, when the SOC (remaining charge) of the battery is below a predetermined threshold value, if there is a charging spot where the predicted value of the waiting time for charging is smaller than the predetermined value, a charging instruction to perform charging is output, so that it is possible to suppress the increase in the waiting time for charging. In this embodiment, during the period from the start time t1 of charging consideration to the end time t5 of charging consideration, the time t4 when the predicted value of the waiting time for charging is the smallest is set as the recommended charging time. Thereby, it is possible to further suppress the increase in the waiting time for charging.

[0037] FIG. 4 is a diagram for explaining a scene of selecting a charging spot C for executing charging from a plurality of charging spots C. In the scene shown in FIG. 4, at the recommended charging time t4, it is assumed that there are a plurality of charging spots C1, C2, C3 in the travelable range (within the dotted line frame) of the vehicle V where the predicted value of the waiting time for charging is calculated. The predicted values of the waiting time for charging at the recommended charging time t4 are 15 minutes for the charging spot C1, 5 minutes for the charging spot C2, and 35 minutes for the charging spot C3, respectively. There are a plurality of charging spots C1, C2 where the predicted value of the waiting time for charging is smaller than the predetermined value of 30 minutes.

[0038] In such a case, in addition to the predicted value of the charging waiting time, the charging plan unit 141 calculates the arrival time until the vehicle V reaches each charging spot C. Then, from the sum of the predicted value of the charging waiting time and the arrival time until reaching the charging spot C, the charging required time until the vehicle V starts charging is calculated.

[0039] For example, in the scene shown in FIG. 4, assuming that the arrival time T1 to the charging spot C1 is 5 minutes and the arrival time T2 to the charging spot C2 is 10 minutes, the charging required time for the charging spot C1 is 20 minutes from the sum of the predicted value of the charging waiting time of 15 minutes and the arrival time of 5 minutes. On the other hand, the charging required time for the charging spot C2 is 15 minutes from the sum of the predicted value of the charging waiting time of 5 minutes and the arrival time of 10 minutes. At this time, the charging plan unit 141 specifies the charging spot C2 with the minimum charging required time as the charging spot C for executing charging and reflects it in the charging plan. Thereby, among a plurality of charging spots C where the predicted value of the charging waiting time is smaller than a predetermined value, the charging spot C with the minimum charging required time including the time until reaching the charging spot C can be specified, so that the charging waiting time can be further suppressed from becoming longer.

[0040] When the charging plan unit 141 formulates a charging plan including information such as a first charging threshold value, a second charging threshold value, a charging consideration start time t1, a charging consideration end time t5, a charging recommendation time t4, a predicted value of the charging waiting time, and a charging spot C for executing charging, it outputs the plan to the charging timing determination unit 145. Based on this charging plan, when the charging recommendation time t4 arrives, the charging timing determination unit 145 transmits a charging command to the in-vehicle control device 3.

[0041] The charge plan correction unit 142 corrects the charge plan based on the current SOC of the battery received from the in-vehicle control device 3 via the communication unit 13. This is because depending on the usage environment and usage pattern of the battery, the SOC may reach the second charge threshold earlier than the predicted arrival time of the second charge threshold calculated by the charge plan unit 141. Specifically, when the SOC reaches the second charge threshold earlier than the charge consideration start time t1 (predicted arrival time of the second charge threshold) defined in the charge plan, the predicted value of the charge waiting time at the time when the SOC of the battery actually reaches the second charge threshold (hereinafter also referred to as the second charge threshold arrival time or the current time) is calculated, and the charge plan is corrected using the correction value of the charge waiting time calculated by the prediction error correction unit 143 described later. The corrected charge plan is output to the charge timing determination unit 145.

[0042] Note that the prediction error correction unit 143 is not an essential configuration of the present invention and may be omitted as necessary. In this case, the charge plan correction unit 142 calculates the predicted value of the charge waiting time at the second charge threshold arrival time, and when there is a charging spot C where the predicted value of the charge waiting time is smaller than a predetermined value, the charge plan may be corrected so that a charge command can be output at a timing earlier than the charge recommendation time t4, and output to the charge timing determination unit 145. Thereby, even when the SOC (remaining charge amount) of the battery reaches the second charge threshold earlier than the initial charge plan, it is possible to suppress the increase in the charge waiting time and execute the charge.

[0043] In addition to calculating the predicted value of the charging waiting time at the time when the second charging threshold is reached, the charging plan correction unit 142 may recalculate the charging consideration end time t5 (the predicted time of reaching the first charging threshold), newly calculate the predicted value of the charging waiting time until the charging consideration end time t5 is reached, and update the charging recommendation time t4. Further, even at a time before the actual SOC of the battery reaches the second charging threshold, the charging plan correction unit 142 recalculates the charging consideration start time t1, the charging consideration end time t5, the predicted value of the charging waiting time from the charging consideration start time t1 to the charging consideration end time t5, and the charging recommendation time t4 based on the current SOC of the battery, and may timely correct the charging plan. Thereby, charging can be executed using a charging plan that reflects the actual SOC of the battery.

[0044] When the current SOC of the battery reaches the second charging threshold, the prediction error correction unit 143 executes a correction process for the charging waiting time. Specifically, it compares the predicted value of the charging waiting time at the current time when the SOC reaches the second charging threshold with the measured value of the actual charging waiting time of the charging spot C at the current time obtained from the charger 2 via the communication unit 13, and calculates a correction value for the charging waiting time.

[0045] FIG. 5A is a graph (upper figure) showing the charging plan formulated in the scene shown in FIG. 2 and the transition of the actual SOC of the battery, and a diagram (lower figure) for explaining the calculation process of the correction value of the charging waiting time. The dashed-dotted line graph in the upper figure shows the predicted transition of the SOC (remaining charge) of the battery with respect to the elapsed time calculated at the time of formulating the charging plan, and the solid line graph shows the transition of the predicted value of the charging waiting time with respect to the elapsed time. In contrast, the dotted line graph shows the transition of the actual SOC of the battery with respect to the elapsed time. The scene shown in FIG. 5A is a scene where the actual SOC of the battery reaches the second charging threshold at time t0, which is earlier than the charging consideration start time t1 set in the charging plan.

[0046] In the scene shown in FIG. 5A, the predicted value Cp0 of the charging waiting time at the current time t0 when the actual SOC of the battery reaches the second charging threshold is 12 minutes. However, the remaining charging time until the other vehicle at the current charging spot C at the current time t0 calculated by the charger 2 actually completes charging is 20 minutes. Let the remaining charging time of 20 minutes until the other vehicle currently charging completes charging be the measured value Cm0 of the charging waiting time. Here, assuming that the vehicle V heads towards the charging spot C at the current time t0, the actual charging waiting time is likely to be longer than the predicted value Cp0 of the charging waiting time, which is 12 minutes. This is because the own vehicle cannot charge until the other vehicle currently charging completes charging. Therefore, the prediction error correction unit 143 sets 20 minutes of the measured value Cm0 of the charging waiting time as the corrected value of the charging waiting time.

[0047] In the scene shown in FIG. 5B, it is different in that there is no other vehicle currently charging at the charging spot C at the current time t0. The predicted value Cp0 of the charging waiting time at the current time t0 when reaching the second charging threshold is 12 minutes, while since there is no other vehicle charging at the charging spot C at the current time t0, the measured value Cm0 of the charging waiting time is 0 minutes. Assuming that the vehicle V heads towards the charging spot C at the current time t0, the actual charging waiting time is likely to be shorter than the predicted value Cp0 of the charging waiting time, which is 12 minutes. Therefore, the prediction error correction unit 143 uses 12 minutes of the predicted value Cp0 of the charging waiting time as it is as the corrected value of the charging waiting time. Incidentally, when the measured value Cm0 of the charging waiting time is smaller than the predicted value Cp0 of the charging waiting time, the corrected value of the charging waiting time may be the average value of the two values. In the scene shown in FIG. 5B, the average value of 0 minutes of the measured value Cm0 of the charging waiting time and 12 minutes of the predicted value Cp0 of the charging waiting time, which is 6 minutes, may be used as the corrected value of the charging waiting time. By using the average value of the two values, the charging plan can be corrected based on a value closer to the actual charging waiting time.

[0048] In this way, when the predicted value of the charging waiting time at the current time t0 when the actual SOC of the battery reaches the second charging threshold value < becomes the measured value of the charging waiting time, the prediction error correction unit 143 uses the measured value of the charging waiting time as the corrected value of the charging waiting time. On the other hand, when the measured value of the charging waiting time < the predicted value of the charging waiting time, the predicted value of the charging waiting time is directly used as the corrected value of the charging waiting time. Thereby, the error of the charging waiting time calculated from the predicted value can be corrected.

[0049] When the prediction error correction unit 143 calculates the corrected value of the charging waiting time, it determines whether the corrected value of the charging waiting time is smaller than the upper limit value of the charging waiting time. The upper limit value of the charging waiting time is not particularly limited, but for example, it is set to the predicted value of the charging waiting time at the recommended charging time t4. Thereby, it is possible to suppress the waiting time from becoming longer than the charging waiting time at the recommended charging time t4 set in the charging plan.

[0050] In the scene shown in FIG. 5A, the corrected value of the charging waiting time at the current time t0 is 20 minutes, while the predicted value of the charging waiting time at the recommended charging time t4 is 15 minutes. On the other hand, in the scene shown in FIG. 5B, the corrected value of the charging waiting time at the current time t0 is 12 minutes, while the predicted value of the charging waiting time at the recommended charging time t4 is 15 minutes. In such a case, the prediction error correction unit 143 determines that the corrected value of the charging waiting time is smaller than the upper limit value of the charging waiting time.

[0051] When it is determined that the corrected value of the charging waiting time is smaller than the upper limit value of the charging waiting time, the prediction error correction unit 143 determines whether the increase amount of the charging waiting time after the current time t0 is larger than a predetermined value. This is because it is better to execute charging at the current time t0 when the increase amount of the charging waiting time after the current time t0 is large. The predetermined value of the increase amount of the charging waiting time is not particularly limited, but for example, it may be set to an arbitrary time such as 10 minutes, or may be set to the increase amount obtained by comparing the measured value of the charging waiting time at the current time t0 with the predicted value of the charging waiting time at the recommended charging time t4. Thereby, charging can be executed in consideration of the possibility that the charging waiting time after the current time t0 becomes long.

[0052] In the scene shown in FIG. 5B, an increase amount of 15 minutes obtained by comparing the measured value Cm0 of 0 minutes of the charging waiting time at the current time t0 with the predicted value Cp4 of 15 minutes of the charging waiting time at the recommended charging time t4 is set as a predetermined value. The increase amount obtained by comparing the corrected value of 12 minutes of the charging waiting time at the current time t0 with the predicted value Cp1 of 28 minutes of the charging waiting time at, for example, time t1 after the current time t0 is 16 minutes. That is, the increase amount of 16 minutes of the charging waiting time after the current time t0 is larger than the predetermined value of 15 minutes. In such a case, the prediction error correction unit 143 determines that the increase amount of the charging waiting time after the current time t0 is larger than the predetermined value.

[0053] When the corrected value of the charging waiting time is smaller than the upper limit value of the charging waiting time and the increase amount of the charging waiting time after the current time t0 is larger than the predetermined value, the prediction error correction unit 143 outputs a charging command at a timing earlier than the recommended charging time t4, and thus transmits the calculation result to the charging plan correction unit 142. Upon receiving this, the charging plan correction unit 142 corrects the charging plan and outputs it to the charging timing determination unit 145. Thereby, the prediction error of the charging waiting time calculated from the usage status of the past charging spot C can be corrected based on the usage status of the current charging spot C.

[0054] The power outage prevention determination unit 144 monitors the SOC of the battery so that the vehicle V does not enter a power outage state. Specifically, when the current SOC of the battery received from the in-vehicle control device 3 via the communication unit 13 reaches the first charging threshold value, a charging command is transmitted to the charging timing determination unit 145 together with a signal indicating that the first charging threshold value has been reached. This is because when the SOC reaches the first charging threshold value, it is better to execute charging regardless of the predicted value of the charging waiting time described above. Thereby, it is possible to suppress the vehicle V from entering a power outage state.

[0055] Based on the charging plan received from the charging plan section 141, the modified charging plan received from the charging plan modification section 142, and the charging command received from the power outage prevention determination section 144, the charging timing determination section 145 transmits a charging command to the in-vehicle control device 3 via the communication section 13. Upon receiving this, the in-vehicle control device 3 controls the autonomous driving of the vehicle V based on a command signal from the control section 31 and drives the vehicle V to the charging spot C where charging is to be executed.

[0056] Based on the charging command received from the charging timing determination section 145, the in-vehicle control device 3 may notify the driver of the vehicle V about the charging action. Each of FIGS. 6(A) and (B) is a diagram showing an example of a display screen on which the charging command is displayed on the in-vehicle control device 3 of the vehicle V. It shows an image to be displayed on the display of the navigation device as the display section 34 provided in the in-vehicle control device 3.

[0057] The display example shown in FIG. 6(A) is the form of the display image when the recommended charging time t4 set in the charging plan is reached. The form of the display image is not particularly limited. For example, together with the SOC (remaining charge) of the battery, a sentence proposing charging such as "The charging spot is not congested. Do you want to charge?" and answer buttons such as "Yes / No" are displayed. In contrast, the display example shown in FIG. 6(B) is the form of the display image when the SOC reaches the first charging threshold before the recommended charging time t4. In this case, in order to charge the vehicle V regardless of the predicted value of the charging waiting time, for example, a sentence prompting charging such as "The remaining charge is low. Please head towards the charging spot." is displayed together with the SOC (remaining charge) of the battery. In this way, by setting the display mode according to the SOC of the battery so that the driver of the vehicle V can choose whether to charge or not until the SOC reaches from the second charging threshold to the first charging threshold, and to force charging when the SOC is less than the first charging threshold, an appropriate charging action can be prompted to the driver of the vehicle V.

[0058] Next, taking the scenes shown in FIGS. 5A and 5B as examples, a control processing example of charging control executed by the charging control device 1 will be described. FIG. 7 is a flowchart showing an example of the charging control process executed by the charging control device 1. FIG. 8 shows a subroutine of step S7 shown in FIG. 7.

[0059] The charging control process described below is executed by the charging control device 1 at a predetermined time interval, for example, when the main power switch of the vehicle V is turned on. Further, in the following, it is assumed that the vehicle V is performing autonomous driving control by the autonomous driving control function of the in-vehicle control device 3.

[0060] In steps S1 to S5 of FIG. 7, the charging planning unit 141 formulates a charging plan for the battery. First, in step S1, a predetermined SOC for preventing the vehicle V from being in a so-called power shortage state is set as the first charging threshold. Next, a predetermined SOC greater than the first charging threshold is set as the second charging threshold, and the process proceeds to step S2. The predetermined SOC greater than the first charging threshold is a value that allows the vehicle V to travel to some extent until it reaches the first charging threshold, such as SOC 35%.

[0061] In step S2, the predicted time when the SOC of the battery reaches the second charging threshold is calculated and set as the charging consideration start time t1. In the subsequent step S3, the predicted time when the SOC of the battery reaches the second charging threshold is calculated and set as the charging consideration end time t5.

[0062] In step S4, a predicted value of the charging waiting time at the charging spot C from the charging consideration start time t1 to the charging consideration end time t5 is calculated. The predicted value of the charging waiting time is calculated based on the charging waiting time calculated from the past usage status of the charging spot C.

[0063] In the subsequent step S5, a time when the predicted value of the charging waiting time becomes smaller than a predetermined value is calculated between the start time t1 of charging consideration and the end time t5 of charging consideration. The predetermined value is, for example, 30 minutes which is the usage time of the charger 2 for one time. The charging plan section 141 sets the time t4 when the predicted value of the charging waiting time is the smallest as the recommended charging time based on the calculation result.

[0064] In step S6, the charging plan correction section 142 determines whether the current SOC of the battery is smaller than the second charging threshold. If the SOC is smaller than the second charging threshold, it proceeds to step S7. On the contrary, step S6 is repeated for a predetermined time until the SOC becomes smaller than the second charging threshold. In step S7, a correction process for the charging waiting time described later is executed.

[0065] When the correction process for the charging waiting time is executed in step S7, in the subsequent step S8, the prediction error correction section 143 determines whether the correction value of the charging waiting time is smaller than the upper limit value of the charging waiting time. If it is determined that the correction value of the charging waiting time is smaller than the upper limit value of the charging waiting time, it proceeds to step S9. On the contrary, if it is determined that the correction value of the charging waiting time is not smaller than the upper limit value of the charging waiting time, it proceeds to step S11. The upper limit value of the charging waiting time is, for example, the predicted value of the charging waiting time at the recommended charging time t4.

[0066] As a result of the determination in step S8, if it is determined that the correction value of the charging waiting time is smaller than the upper limit value of the charging waiting time, in step S9, it is determined whether the increase amount of the charging waiting time after the current time t0 when the second charging threshold is reached is larger than a predetermined value. The predetermined value of the increase amount of the charging waiting time is set, for example, to the increase amount obtained by comparing the measured value of the charging waiting time at the current time t0 and the predicted value of the charging waiting time at the recommended charging time t4.

[0067] If, as a result of the determination in step S9, the increase in the charging wait time after the current time t0 is greater than a predetermined value, then it is less likely that the charging wait time will become longer if charging is executed at the timing of the current time t0. Therefore, the process proceeds to step S10 and a charging command is output.

[0068] If, as a result of the determination in step S8, it is determined that the corrected value of the charging wait time is not less than the upper limit value of the charging wait time, then in step S11, it is determined whether the current SOC of the battery is less than the first charging threshold.

[0069] If, as a result of the determination in step S11, it is determined that the current SOC of the battery is less than the first charging threshold, then in order to prevent the vehicle V from running out of power, the process proceeds to step S10 and a charging command is output.

[0070] On the other hand, if, as a result of the determination in step S9, it is determined that the increase in the charging wait time after the current time t0 is not greater than the predetermined value, and if, as a result of the determination in step S11, it is determined that the current SOC of the battery is not less than the first charging threshold, then in step S12, it is determined whether it is the charging recommended time t4. If it is determined that it is the charging recommended time t4, then the process proceeds to step S10 and a charging command is output. On the other hand, step S12 is repeated for a predetermined time until the charging recommended time t4 is reached.

[0071] In step S7 of FIG. 7, the correction process of the charging wait time and the process shown in FIG. 8 are executed. First, in step S71, a predicted value of the charging wait time at the current time t0 when the SOC of the battery actually reaches the second charging threshold is calculated, and the process proceeds to step S72.

[0072] In step S72, the prediction error correction unit 143 acquires a measured value of the charging wait time at the current time t0. The measured value of the charging wait time is calculated based on the remaining charging time until another vehicle currently charging at the charging spot C completes charging.

[0073] In the subsequent step S73, the predicted value of the charging waiting time at the current time t0 when the SOC of the battery reaches the second charging threshold is compared with the measured value of the actual charging waiting time of the charging spot C at the current time t0, and a corrected value of the charging waiting time is calculated. As shown in FIG. 5A, when the predicted value of the charging waiting time < the measured value of the charging waiting time, the prediction error correction unit 143 sets the measured value of the charging waiting time as the corrected value of the charging waiting time. On the other hand, as shown in FIG. 5B, when the measured value of the charging waiting time < the predicted value of the charging waiting time, the predicted value of the charging waiting time is set as the corrected value of the charging waiting time, and the process proceeds to step S8.

[0074] As described above, according to the charging control method and the charging control device 1 of the present embodiment, a first charging threshold at which charging of the running drive battery is required and a second charging threshold at which the SOC (remaining charge) is greater than the first charging threshold are set, the SOC (remaining charge) is detected and compared with the first charging threshold and the second charging threshold, and when the SOC (remaining charge) is smaller than the second charging threshold and greater than the first charging threshold, when there is a charging spot C where the predicted value of the charging waiting time is smaller than a predetermined value, a charging instruction to perform charging is output. Thereby, when the remaining charge of the running drive battery is equal to or less than a predetermined threshold, it is possible to suppress an increase in the charging waiting time.

[0075] Further, according to the charging control method and the charging control device 1 of the present embodiment, when the SOC (remaining charge) becomes smaller than the second charging threshold, the predicted value of the charging waiting time at the charging spot C is calculated, and when there is a charging spot C where the predicted value of the charging waiting time is smaller than a predetermined value, a charging instruction is output. Therefore, even when the SOC (remaining charge) of the battery reaches the second charging threshold earlier than the original charging plan, it is possible to suppress an increase in the charging waiting time and execute charging.

[0076] Further, according to the charging control method and the charging control device 1 of the present embodiment, when the SOC (remaining charge) is smaller than the first charging threshold, a charging instruction is output regardless of the charging waiting time, so that it is possible to suppress the vehicle V from being in a power-off state.

[0077] Also, according to the charging control method and the charging control device 1 of the present embodiment, the output display of the charging instruction when the SOC (remaining charge) is less than the second charging threshold and greater than the first charging threshold, and the output display of the charging instruction when the SOC (remaining charge) is less than the first charging threshold, are in different display modes. When the SOC (remaining charge) ranges from the second charging threshold to the first charging threshold, the driver can select whether to charge or not. When the SOC (remaining charge) is less than the first charging threshold, a display mode corresponding to the SOC (remaining charge) of the battery, such as forcing charging, is adopted, so that the driver of the vehicle V can be prompted to take appropriate charging actions.

[0078] Also, according to the charging control method and the charging control device 1 of the present embodiment, since the charging instruction is output to the in-vehicle control device 3 of the vehicle V, the vehicle V can be smoothly charged by autonomous driving.

[0079] Also, according to the charging control method and the charging control device 1 of the present embodiment, when there are a plurality of charging spots C where the predicted value of the charging waiting time is less than a predetermined value, the vehicle V calculates the driving time required until it arrives at each charging spot C, and calculates the charging required time consisting of the sum of the charging waiting time at the charging spot C and the driving time required until it arrives at the charging spot. Then, it searches for the charging spot C with the minimum charging required time and outputs a charging instruction. As a result, among the plurality of charging spots C where the predicted value of the charging waiting time is less than the predetermined value, the charging spot C with the minimum charging required time including the time required to reach the charging spot C can be specified, so that the increase in the charging waiting time can be further suppressed.

[0080] Further, according to the charging control method and the charging control device 1 of the present embodiment, a correction value of the charging waiting time is calculated from a predicted value of the charging waiting time at the current time t0 when the SOC (remaining charge) reaches the second charging threshold, and a measured value of the charging waiting time at the current time t0 calculated from the time until another vehicle currently charging at the charging spot C completes charging. When the correction value of the charging waiting time is smaller than the upper limit value of the charging waiting time and the increase amount of the charging waiting time after the current time t0 is larger than a predetermined value, a charging instruction is output. Thereby, the prediction error of the charging waiting time calculated from the usage status of the past charging spot C can be corrected based on the usage status of the current charging spot C.

[0081] Further, according to the charging control method and the charging control device 1 of the present embodiment, when the measured value of the charging waiting time at the current time t0 is larger than the predicted value of the charging waiting time at the current time t0, the correction value of the charging waiting time is set to the measured value of the charging waiting time, so that the error of the charging waiting time calculated from the predicted value can be corrected.

[0082] Further, according to the charging control method and the charging control device 1 of the present embodiment, the upper limit value of the charging waiting time is calculated based on the minimum value of the predicted values of the charging waiting time from the predicted time t1 when the SOC (remaining charge) reaches the second charging threshold to the predicted time t5 when it reaches the first charging threshold. Therefore, it is possible to suppress the waiting time from becoming longer than the charging waiting time at the recommended charging time t4 set in the charging plan.

[0083] Further, according to the charging control method and the charging control device 1 of the present embodiment, the increase amount of the charging waiting time after the current time t0 is calculated based on the increase amount obtained by comparing the measured value of the charging waiting time at the current time t0 with the minimum value of the predicted values of the charging waiting time from the predicted time t1 when the SOC (remaining charge) reaches the second charging threshold to the predicted time t5 when it reaches the first charging threshold. Thereby, charging can be executed in consideration of the possibility that the charging waiting time after the current time t0 becomes longer.

[0084] In addition, according to the charging control method and the charging control device 1 of the present embodiment, since the predicted value of the waiting time for charging at the charging spot C is calculated based on the past usage status at the charging spot C, it is possible to calculate an appropriate predicted value of the waiting time for charging based on the measured value.

[0085] Note that the embodiments described above are described for facilitating the understanding of the present invention, and are not described for limiting the present invention. Therefore, each element disclosed in the above embodiments is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

Explanation of Reference Numerals

[0086] S…Charging control system 1…Charging control device 11…Vehicle database 12…Charging spot database 13…Communication unit 14…Control unit 2…Charger 21…Control unit 22…Sensor 23…Communication unit 3…In-vehicle control device 31…Control unit 32…Charging capacity detection unit 33…Communication unit 34…Display unit V…Vehicle C…Charging spot NW…Telecommunication line network

Claims

1. A charging control method for giving a charging instruction based on the remaining charge of a driving battery mounted on a vehicle and the waiting time for charging calculated from the usage status of charging spots, comprising: setting a first charging threshold at which charging of the driving battery is required and a second charging threshold at which the remaining charge is greater than the first charging threshold; detecting the remaining charge and comparing it with the first charging threshold and the second charging threshold; in a charging control method for outputting a charging instruction to charge when there is a charging spot where the predicted value of the charging waiting time is less than a predetermined value when the remaining charge is less than the second charging threshold and greater than the first charging threshold; at the current time when the remaining charge reaches the second charging threshold; calculating a correction value of the charging waiting time from the predicted value of the charging waiting time at the current time and the measured value of the charging waiting time at the current time calculated from the time until another vehicle currently charging at the charging spot finishes charging, which is calculated from the charging spot and obtained from the charging spot; a charging control method for outputting the charging instruction at the current time when the correction value of the charging waiting time is less than the upper limit value of the charging waiting time and the increase amount of the predicted value of the charging waiting time after the current time with respect to the measured value of the charging waiting time at the current time is greater than a predetermined value.

2. when the remaining charge becomes less than the second charging threshold; calculating a predicted value of the charging waiting time at the charging spot; The charging control method according to claim 1, wherein when there is a charging spot where the predicted value of the charging waiting time is less than a predetermined value, the charging instruction is output.

3. The charging control method according to claim 1 or 2, wherein when the remaining charge is less than the first charging threshold, the charging instruction is output regardless of the charging waiting time.

4. the output display of the charging instruction when the remaining charge is less than the second charging threshold and greater than the first charging threshold; and the output display of the charging instruction when the remaining charge is less than the first charging threshold are in different display modes. The charging control method according to any one of claims 1 to 3.

5. The charging control method according to any one of claims 1 to 4, wherein the charging instruction is output to an in-vehicle device of the vehicle.

6. when there are a plurality of charging spots where the predicted value of the charging waiting time is less than a predetermined value; The vehicle calculates the travel time required until it arrives at each of the charging spots, calculates the charging required time, which is the sum of the waiting time for charging at the charging spot and the travel time required until arriving at the charging spot, searches for a charging spot with the minimum charging required time, and outputs the charging instruction. The charging control method according to any one of claims 1 to 5.

7. When the measured value of the waiting time for charging at the current time is greater than the predicted value of the waiting time for charging at the current time, the correction value of the waiting time for charging is set to the measured value of the waiting time for charging. The charging control method according to any one of claims 1 to 6.

8. The upper limit value of the waiting time for charging is calculated based on the minimum value of the predicted values of the waiting time for charging from the predicted time when the remaining charge amount reaches the second charging threshold to the predicted time when it reaches the first charging threshold. The charging control method according to any one of claims 1 to 7.

9. The increase amount of the waiting time for charging after the current time is calculated based on the increase amount obtained by comparing the measured value of the waiting time for charging at the current time with the minimum value of the predicted values of the waiting time for charging from the predicted time when the remaining charge amount reaches the second charging threshold to the predicted time when it reaches the first charging threshold. The charging control method according to any one of claims 1 to 8.

10. The predicted value of the waiting time for charging at the charging spot is calculated based on the past usage status at the charging spot. The charging control method according to any one of claims 1 to 9.

11. A charging control device including a processor that gives a charging instruction based on the remaining charge amount of a driving battery mounted on a vehicle and the waiting time for charging calculated from the usage status of the charging spot, wherein the processor sets a first charging threshold at which charging of the driving battery is required and a second charging threshold at which the remaining charge amount is greater than the first charging threshold, detects the remaining charge amount and compares it with the first charging threshold and the second charging threshold, when the remaining charge amount is less than the second charging threshold and greater than the first charging threshold, and there is a charging spot where the predicted value of the waiting time for charging is less than a predetermined value, outputs a charging instruction to perform charging, at the current time when the remaining charge amount has reached the second charging threshold, From the predicted value of the charging waiting time at the current time and the measured value of the charging waiting time at the current time calculated from the time until the other vehicle currently charging at the charging spot completes charging, which is calculated by the charging spot and obtained from the charging spot, the correction value of the charging waiting time is calculated. A charging control device that outputs the charging instruction at the current time when the correction value of the charging waiting time is smaller than the upper limit value of the charging waiting time and the increase amount of the predicted value of the charging waiting time after the current time with respect to the measured value of the charging waiting time at the current time is larger than a predetermined value.

Images