vehicle

Abstract

By appropriately displaying parameters indicating the vehicle's status, user convenience is enhanced. [Solution] The vehicle comprises a battery, a display device, and a control device. The control device estimates the degree of battery degradation and controls the display device so that a parameter indicating the estimated degree of degradation is displayed. When the control program is rewritten, the control device determines whether the first identification information of the control program before rewriting and the second identification information of the control program after rewriting match. If the first identification information and the second identification information match, the control device controls the display device so that a first mileage expressed in a predetermined format is displayed. If the first identification information and the second identification information do not match, the display device controls the display device so that a second mileage is displayed. The first mileage is the cumulative mileage traveled by the vehicle after the above parameter has been updated. The second mileage is the maximum value in the above predetermined format.

Description

Technical Field

[0001] The present disclosure relates to a vehicle.

Background Art

[0002] Japanese Patent Application Laid-Open No. 2003-164006 (Patent Document 1) discloses a display device that displays the capacity of a vehicle battery. This display device has a plurality of segments (first display means) that display the remaining battery level (charge amount), which changes over time with power consumption, in stages, and an Empty indicator lamp (second display means) that lights up when the remaining battery level falls below a threshold value. In the Empty indicator lamp, the threshold value changes according to the degree of deterioration of the vehicle battery.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The display device described in Patent Document 1 estimates the degree of deterioration of the battery and determines the remaining battery level (threshold value) when the Empty indicator lamp lights up based on the degree of deterioration of the battery. However, an accurate degree of deterioration of the battery cannot always be obtained. If notification processing is executed based on a low reliability degree of deterioration, it may rather reduce the convenience for the user. For example, if the Empty indicator lamp lights up even though there is still sufficient charge (remaining battery level), it becomes difficult for the user to accurately grasp the state of the vehicle.

[0005] The present disclosure has been made to solve the above problems, and an object thereof is to enhance the convenience for the user by appropriately displaying parameters indicating the state of the vehicle.

Means for Solving the Problems

[0006] According to one embodiment of the present disclosure, a vehicle is provided. The vehicle comprises a battery, a display device, and a control device. The control device comprises a storage device for storing a control program relating to the battery, and a processor for executing the control program. The control device is configured to estimate the degree of battery degradation and to control the display device so that parameters indicating the estimated degree of degradation are displayed. When the control program is rewritten, the control device determines whether a first identification information of the control program before rewriting matches a second identification information of the control program after rewriting. If the first identification information and the second identification information match, the control device controls the display device so that a first mileage expressed in a predetermined format is displayed. If the first identification information and the second identification information do not match, the display device controls the display device so that a second mileage is displayed. The first mileage is the cumulative mileage traveled by the vehicle after the update of the above parameters. The second mileage is the maximum value in the above predetermined format. [Effects of the Invention]

[0007] According to this disclosure, it is possible to improve user convenience by appropriately displaying parameters that indicate the status of the vehicle. [Brief explanation of the drawing]

[0008] [Figure 1] This figure shows the configuration of a vehicle according to an embodiment of the present disclosure. [Figure 2] This is a flowchart showing the SOH update process according to an embodiment of the present disclosure. [Figure 3] This flowchart shows the display control according to the embodiment of the present disclosure. [Figure 4] This diagram illustrates an example of program rewriting. [Figure 5] This figure shows an example of the operation of a display device according to the display control shown in Figure 3. [Modes for carrying out the invention]

[0009] Embodiments of this 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 descriptions will not be repeated.

[0010] Figure 1 is a diagram showing the configuration of a vehicle according to this embodiment. Referring to Figure 1, the vehicle 1 comprises a vehicle body 10 and a battery pack 20. The vehicle body 10 is the part of the vehicle 1 other than the battery pack 20. The battery pack 20 corresponds to an example of an "energy storage device" according to this disclosure.

[0011] The vehicle body 10 includes an MG (Motor Generator) 11a, an inverter 11b, an SMR (System Main Relay) 13, a DC charging relay 14a, a DC inlet 14b, an AC charger 15a, an AC inlet 15b, a DC / DC converter 16, an auxiliary battery 17, an HMI (Human Machine Interface) 18, a vehicle sensor 19, and a vehicle ECU 100. The battery pack 20 includes a battery 21, a monitoring unit 22, and a battery ECU 200. "ECU" means Electronic Control Unit. The battery ECU 200 corresponds to an example of a "control device" according to this disclosure. The vehicle 1 is configured to run using the power output from the battery 21. The vehicle 1 is, for example, an electric vehicle (BEV) without an internal combustion engine. However, it is not limited to this, and the vehicle 1 may be a PHEV (Plug-in Hybrid Electric Vehicle) equipped with an internal combustion engine, or another electric vehicle (xEV).

[0012] The vehicle ECU 100 includes a processor 110 and a storage device 120. The battery ECU 200 includes a processor 210 and a storage device 220. Each storage device is configured to store the stored information. In addition to the program, each storage device stores various information used by the program. In each ECU, various controls are performed by the processor executing the program stored in the storage device.

[0013] The vehicle ECU 100 and the battery ECU 200 are configured to communicate with each other. The vehicle ECU 100 is configured to receive detection signals from various sensors included in the vehicle sensor 19 and to control various devices mounted on the vehicle body 10. In this embodiment, the vehicle sensor 19 includes a mileage meter (e.g., an odometer). The battery ECU 200 is configured to monitor the state of the battery 21 and send control commands related to the battery 21 to the vehicle ECU 100. The battery ECU 200 can control various devices mounted on the vehicle body 10 via the vehicle ECU 100. The vehicle ECU 100 controls the inverter 11b, SMR 13, DC charging relay 14a, AC charger 15a, DC / DC converter 16, and HMI 18, which are described below, either in response to a request from the battery ECU 200 or spontaneously.

[0014] The MG11a functions as a motor for driving. The inverter 11b functions as a PCU (Power Control Unit) for the MG11a. The inverter 11b drives the MG11a using power supplied from the battery 21. The MG11a converts power into torque, which rotates the drive wheels of the vehicle 1. The MG11a also regenerates power, for example when the vehicle 1 is decelerating, to charge the battery 21. The SMR13 switches the connection / disconnection of the electrical circuit between the battery 21 and the inverter 11b.

[0015] The DC inlet 14b and AC inlet 15b are configured to accept DC and AC charging cables, respectively. Each of the DC inlet 14b and AC inlet 15b has a terminal for detecting whether a charging cable (charging plug) is connected or not, and outputs a signal to the vehicle ECU 100 indicating whether a charging cable is connected or not. When charging the battery 21 with DC power input to the DC inlet 14b from outside the vehicle, the vehicle ECU 100 closes the SMR 13 and the DC charging relay 14a (connected state). The AC charger 15a performs AC / DC conversion. When charging the battery 21 with AC power input to the AC inlet 15b from outside the vehicle, the vehicle ECU 100 controls the AC charger 15a when the SMR 13 is closed (connected state) and AC power is being input to the AC charger 15a from outside the vehicle via the AC inlet 15b. The AC charger 15a converts AC power to DC power according to control commands from the vehicle ECU 100 and outputs the DC power to the battery 21. The vehicle 1 is configured to perform external charging (charging of the battery 21 with power supplied from outside the vehicle) via the DC inlet 14b or AC inlet 15b while parked. Alternatively, the vehicle 1 may be configured to perform external power supply (power supply that outputs the power of the battery 21 to the outside of the vehicle) via the DC inlet 14b or AC inlet 15b while parked.

[0016] The DC / DC converter 16 transforms the DC power. For example, the DC / DC converter 16 steps down the DC power from the battery 21 and outputs it to the auxiliary battery 17. The auxiliary battery 17 supplies power to drive the auxiliary equipment mounted on the vehicle 1. The auxiliary battery 17 outputs power at a voltage lower than the voltage of the battery 21. The capacity of the battery 21 is greater than the capacity of the auxiliary battery 17. The vehicle ECU 100 may control the DC / DC converter 16 so that power is supplied from the battery 21 to the auxiliary battery 17 when the remaining charge of the auxiliary battery 17 becomes low. The auxiliary battery 17 may supply power to the battery pack 20. The battery ECU 200 may receive power from the auxiliary battery 17.

[0017] The HMI18 includes an input device and a display device. The HMI18 may also include a touch panel display. The input device outputs a signal to the vehicle ECU100 in response to user input. In this embodiment, the HMI18 includes a start switch for the vehicle 1. Generally, a start switch is referred to as a "power switch" or "ignition switch." The display device is controlled by the vehicle ECU100.

[0018] The battery 21 is a rechargeable battery, such as a lithium-ion battery, nickel-metal hydride battery, or sodium-ion battery. The type of rechargeable battery may be a liquid-type rechargeable battery or an all-solid-state rechargeable battery. Multiple rechargeable batteries may form a battery pack. The monitoring unit 22 includes a voltage sensor 22a for detecting the voltage of the battery 21, a current sensor 22b for detecting the current of the battery 21, and a temperature sensor 22c for detecting the temperature of the battery 21. The detection results of each sensor included in the monitoring unit 22 are output to the battery ECU 200. The monitoring unit 22 and the battery ECU 200 may function as a BMS (Battery Management System). The battery ECU 200 is configured to obtain the State of Charge (SOC) of the battery 21 using the sensor detection values ​​output from the monitoring unit 22. SOC indicates the charge level, for example, the ratio of the current charge to the charge in a fully charged state, expressed as 0 to 100%.

[0019] The storage device 220 of the battery ECU 200 stores the SOH (State of Health) of the battery 21 and the distance after SOH update. The SOH of the battery 21 is a parameter indicating the degree of deterioration of the battery 21. In this embodiment, the capacity retention rate is adopted as the SOH. The capacity retention rate indicates the ratio of the current capacity to the initial capacity. As the degree of deterioration of the battery 21 increases, the capacity retention rate of the battery 21 decreases. The storage device 220 stores the estimated value and the display value of the SOH of the battery 21 separately. Initially, each of the estimated value and the display value of the SOH (capacity retention rate) is set to 100%. However, the SOH estimated value indicates the gross value of the estimated SOH. On the other hand, the SOH display value indicates the net value of the SOH displayed on the display device. Details of these gross values and net values will be described later. The distance after SOH update indicates the integrated travel distance that the vehicle 1 has traveled after the update of the SOH display value. In other words, the distance after SOH update indicates the integrated value of the distance that the vehicle 1 has traveled while the SOH display value remains unchanged.

[0020] Figure 2 is a flowchart showing the SOH update process by the battery ECU 200. The processing flow F1 shown in Figure 2 is repeatedly executed by the battery ECU 200. "S" in the flowchart means step.

[0021] Referring to Figure 2, in the processing flow F1, at S11, the battery ECU 200 acquires the OCV (Open Circuit Voltage) of the battery 21 by the voltage sensor 22a. In the subsequent S12, the battery ECU 200 determines whether a predetermined condition (hereinafter referred to as the "start condition") is satisfied. If the start condition is not satisfied (NO in S12), the battery ECU 200 measures the time until the start condition is satisfied at S13. The time measured at S13 indicates the length of the vehicle parking period (that is, the period during which neither driving, external charging, nor external power supply is performed). While the start condition is not satisfied, the processes of S12 and S13 are repeated at a predetermined calculation cycle.

[0022] In this embodiment, the above start condition is met when the absolute value of the amount of charge change per unit time is equal to or greater than a predetermined value (hereinafter referred to as the "first threshold"). The amount of charge change indicates the magnitude of the change in the amount of energy stored in the battery 21. The amount of charge change is indicated by, for example, a positive value for the change on the charging side and a negative value for the change on the discharging side. Specifically, in S12, the battery ECU 200 acquires the current value of the battery 21 using the current sensor 22b and stores the obtained current value in the storage device 220, linked to the acquisition time. The battery ECU 200 then calculates the amount of charge change per unit time of the battery 21. The unit time is, for example, the above calculation period. If the absolute value of the calculated amount of charge change is equal to or greater than the first threshold, the battery ECU 200 determines that the start condition is met. When the above-mentioned external charging is started in the vehicle 1, the amount of charge change increases to the positive side, and the absolute value of the amount of charge change per unit time exceeds the first threshold. When vehicle 1 starts running using the power of battery 21, the amount of charge change becomes large on the negative side, and the absolute value of the amount of charge change per unit time exceeds the first threshold.

[0023] If the start condition is met (YES in S12), the battery ECU 200 acquires the State of Charge (SOC) of the battery 21 in S14 (hereinafter referred to as "start SOC"). The start SOC corresponds to the SOC (gross value) of the battery 21 when the start condition is met. For example, the storage device 220 has pre-stored a map (OCV-SOC curve) showing the relationship between the OCV and SOC (gross value) of the battery 21 in its initial state (undegraded). The battery ECU 200 may refer to such a map and acquire the SOC (gross value) of the battery 21 from the OCV of the battery 21 acquired in S11. The battery ECU 200 may use the obtained SOC of the battery 21 as the start SOC. Alternatively, the battery ECU 200 may correct the obtained SOC of the battery 21 using at least one of the current value of the battery 21 (change in stored charge) obtained in S12, the time measured in S13 (vehicle standby period), and the temperature of the battery 21 obtained by the temperature sensor 22c, and use the corrected SOC as the starting SOC.

[0024] Next, the battery ECU 200 calculates the change in stored energy in S15. Then, in S16, the battery ECU 200 determines whether a predetermined condition (hereinafter referred to as the "termination condition") is met. If the termination condition is not met (NO in S16), the process returns to S15. As long as the termination condition is not met, the processes of S15 and S16 are repeated in the aforementioned calculation cycle.

[0025] In this embodiment, the termination condition is met when the absolute value of the amount of charge change per unit time falls below a predetermined value (hereinafter referred to as the "second threshold"). The second threshold is a value less than or equal to the first threshold. The unit time is, for example, the calculation cycle described above. Specifically, in S15, the battery ECU 200 acquires the current value of the battery 21 using the current sensor 22b and stores the obtained current value in the storage device 220, linked to the acquisition time. The battery ECU 200 then calculates the amount of charge change per unit time of the battery 21 and integrates the amount of charge change using the obtained amount of charge change per unit time. The process in S15 is repeated during the period from when the start condition is met until the termination condition is met (hereinafter referred to as the "target period"), thereby obtaining the amount of charge change during the target period. The termination condition is met when the absolute value of the amount of charge change per unit time falls below the second threshold. For example, if the external charging that was being performed in the vehicle 1 is stopped, the absolute value of the amount of charge change per unit time falls below the second threshold. Furthermore, even when vehicle 1, which was in motion, comes to a stop, the absolute value of the amount of change in stored energy per unit time falls below the second threshold.

[0026] If the termination condition is met (YES in S16), the battery ECU 200 acquires the OCV of the battery 21 using the voltage sensor 22a in S17, and uses the obtained OCV to acquire the SOC of the battery 21 (hereinafter referred to as "termination SOC"). The termination SOC corresponds to the SOC (gross value) of the battery 21 when the termination condition is met. The battery ECU 200 may, for example, refer to the aforementioned map (OCV-SOC curve) to acquire the SOC (gross value) of the battery 21 from the OCV of the battery 21. The battery ECU 200 may use the obtained SOC of the battery 21 as the termination SOC. Alternatively, the battery ECU 200 may correct the obtained SOC of the battery 21 with the temperature of the battery 21 and use the corrected SOC as the termination SOC.

[0027] In step S18, the battery ECU200 calculates the capacity C1 of the battery 21 according to the following formula (1). The capacity C1 corresponds to the amount of energy stored in the battery 21 when fully charged.

[0028] C1=100×dST / |SOC1-SOC2| …(1) In equation (1), the starting SOC is represented as "SOC1", the ending SOC as "SOC2", and the amount of energy stored during the target period as "dST". |SOC1-SOC2| corresponds to the difference (absolute value) between the starting SOC and the ending SOC. For example, if the amount of charging power (amount of power input to battery 21 by external charging) when the SOC of battery 21 was increased from 10% to 60% by external charging during the target period was "25kWh", then the capacity C1 of battery 21 calculated according to equation (1) will be "50kWh (=100×25 / 50)". The battery ECU 200 stores the calculated capacity C1 in the memory device 220, linked to the acquisition time.

[0029] Next, in S19, the battery ECU200 calculates the capacity retention rate (SOH) of the battery 21 according to equation (2) shown below.

[0030] SOH = 100 × C1 / C0 …(2) In equation (2), the capacity (gross value) of the battery 21 in its initial state (undegraded) is represented by "C0". C0 is pre-stored in, for example, the memory device 220. As described above, the battery ECU 200 obtains the capacity retention rate of the battery 21 by dividing C1, calculated in S18, by C0. The battery ECU 200 then stores the calculated capacity retention rate (SOH) in the memory device 220, linked to the acquisition time.

[0031] In the following S20, the battery ECU200 determines whether or not to update the SOH estimate. For example, the battery ECU200 decides to update the SOH estimate if |SOC1-SOC2| is greater than or equal to the first reference value, and decides not to update the SOH estimate if |SOC1-SOC2| is less than the first reference value. If |SOC1-SOC2| is greater than or equal to the first reference value, it means that the SOH has been estimated with sufficiently high accuracy.

[0032] If it is determined that the SOH estimate should be updated (YES in S20), the battery ECU 200 updates the SOH estimate stored in the memory device 220 in S21. Specifically, the battery ECU 200 may determine the latest SOH estimate (gross value) using the capacity C1 calculated in the current processing routine (S18), the capacity C1 calculated in the previous processing routine (S18), the first reference value, and the second reference value. The second reference value is greater than the first reference value. For example, if |SOC1-SOC2| is greater than or equal to the second reference value in the current processing routine, the battery ECU 200 uses the capacity retention rate calculated in the current processing routine (S19) as the latest SOH estimate. In this case, the capacity C1 calculated in the current processing routine (S18) corresponds to the estimated capacity of the battery 21. On the other hand, if |SOC1-SOC2| is greater than or equal to the first reference value and less than the second reference value in the current processing routine, the battery ECU 200 uses the average value of a predetermined number of the most recent data (for example, 2 to 10) of the capacity C1 data (excluding data where |SOC1-SOC2| is less than the first reference value) calculated in the current or previous processing routine (S18) as the estimated capacity of battery 21. Then, the battery ECU 200 substitutes the obtained estimated capacity of battery 21 into "C1" in equation (2) to calculate "SOH", and uses the obtained SOH value as the latest estimated SOH value.

[0033] In the subsequent S22, the battery ECU 200 updates the SOH display value stored in the memory device 220. More specifically, the battery ECU 200 converts the updated SOH estimated value (gross value) into a net value. The gross value, which indicates the characteristics of the battery 21 (capacity, SOC, capacity retention rate, etc.), is a numerical value that indicates the characteristics of the battery 21 alone. The net value, which indicates the characteristics of the battery 21, is a numerical value that indicates the characteristics of the battery 21 when it is installed in the vehicle 1. In this embodiment, the battery ECU 200 limits the usable SOC range (practical range) of the battery 21 based on the SOC lower limit and SOC upper limit determined by the control program. The battery ECU 200 is configured to control the SOC of the battery 21 within the range from the SOC lower limit to the SOC upper limit. The SOC lower limit and SOC upper limit are set, for example, to suppress the degradation of the battery 21. These values ​​are set using the gross value scale. Therefore, if the gross value scale changes due to battery degradation, the SOC lower limit and SOC upper limit will also change. For example, the lower limit of SOC and the upper limit of SOC may be located at "10%" and "90%" on the gross value scale, respectively. However, the net value of SOC is expressed with the lower limit of SOC as "0%" and the upper limit of SOC as "100%". The net value of the capacity of battery 21 corresponds to the amount of energy input to battery 21 by increasing the SOC of battery 21 from the lower limit of SOC to the upper limit of SOC. For this reason, the net value of the capacity of battery 21 will be smaller than the gross value of the capacity of battery 21. The battery ECU 200 converts the estimated value (gross value) of the capacity of battery 21 obtained in S21 into a net value based on the lower limit of SOC and the upper limit of SOC. The obtained estimated value (net value) of the capacity of battery 21 corresponds to the estimated value of the capacity of battery 21 from the lower limit of SOC to the upper limit of SOC. Furthermore, the battery ECU 200 converts the initial capacity (gross value) of battery 21 to a net value based on the lower and upper limits of the State of Charge (SOC). Then, the battery ECU 200 substitutes the estimated capacity (net value) of battery 21 and the initial capacity (net value) of battery 21 into "C1" and "C0" in equation (2), respectively, to calculate "SOH". The calculated SOH value (capacity retention rate) corresponds to the net value of the estimated SOH.In S22, the battery ECU200 sets the estimated SOH value (net value) obtained as described above as the SOH display value. Once the process in S22 is executed, the process returns to the first step (S11).

[0034] In this processing routine, if |SOC1-SOC2| is less than the first reference value (NO in S20), the SOH estimated value stored in the memory device 220 remains at its current value. In this case, the processes in S21 and S22 are not executed, and the process returns to the first step (S11). Therefore, the displayed SOH value is not updated.

[0035] In the processing flow F1 shown in Figure 2, the start and end conditions described above can be changed as appropriate. For example, the start condition may be met only when external charging is started in vehicle 1. Also, in a configuration in which vehicle 1 is capable of receiving external power, the start condition may be met when external power is supplied to vehicle 1. The end condition may be met when external charging or external power supply is stopped in vehicle 1.

[0036] Figure 3 is a flowchart showing the display control by the battery ECU 200. The processing flow F2 shown in Figure 3 is repeatedly executed by the battery ECU 200. Processing flow F2 is executed in parallel with processing flow F1 shown in Figure 2.

[0037] Referring to Figure 3, in processing flow F2, the battery ECU 200 determines in S31 whether the SOH display value has been updated. If the SOH display value has been updated by the processing in S22 in Figure 2, it is determined to be YES in S31 and the process proceeds to S35. On the other hand, if the SOH display value has not been updated, it is determined to be NO in S31 and the process proceeds to S32. In S32, the battery ECU 200 determines whether the SOH display value has never been updated in the past. If the SOH display value has never been updated since vehicle 1 was shipped, it is determined to be YES in S32 and the process proceeds to S33. In this case, the SOH display value remains at its initial value (100%). In S33, the battery ECU 200 sets the maximum value for the distance after SOH update. In this embodiment, the distance after SOH update is represented in 16-bit binary format. Therefore, the maximum value for the distance after SOH update is 65535km. Next, in S34, the battery ECU200 controls the display device of the HMI18 so that the SOH display value and the distance since the SOH update are displayed. As a result of the processing in S34, the display device displays the initial value of the SOH display value (100%) and the maximum value of the distance since the SOH update (65535km). Once the processing in S34 is completed, the process returns to the first step (S31).

[0038] If the SOH display value is updated by the process in S22 of Figure 2 (YES in S31), the battery ECU 200 sets the minimum value (0km) for the distance after SOH update in S35. Then the process proceeds to S34. In the process of S34, the display device displays the updated SOH display value and the minimum value (0km) for the distance after SOH update. Also, because the SOH display value has been updated, from this point onward, S32 will be judged as NO.

[0039] If NO is determined in S32, the battery ECU 200 determines in S36 whether or not it has received a program rewrite request. The program rewrite request will be described later (see Figure 4). If the battery ECU 200 has not received a program rewrite request (NO in S36), the process proceeds to S37. In S37, the battery ECU 200 updates the SOH update distance stored in the storage device 220. Specifically, the battery ECU 200 obtains the measurement value from the odometer from the vehicle ECU 100 and accumulates the distance traveled by vehicle 1 since 0km was set for the SOH update distance in S35. The battery ECU 200 then sets the obtained accumulated value as the SOH update distance. After that, the process proceeds to S34. In the process of S34, the display device displays the current SOH display value and the updated SOH update distance. From this point onward, as long as NO is determined in S31, S32, and S36, the distance after SOH update will be repeatedly updated in S37.

[0040] If the battery ECU200 receives a program rewrite request (YES in S36), the process proceeds to S41. The process from S41 onwards will be explained below using Figures 3 and 4. Figure 4 is a diagram illustrating an example of program rewriting.

[0041] The dealer shown in Figure 4 includes a server 610 configured to communicate wirelessly with vehicle 1 and a scan tool 620 configured to communicate wired with vehicle 1. The scan tool 620 is an external diagnostic device used by a service provider (e.g., a mechanic) to determine the status of vehicle 1. The service provider or vehicle user can request a program rewrite from the battery ECU 200 via an external terminal or an in-vehicle terminal. In this embodiment, the server 610 and the scan tool 620 each function as external terminals. The vehicle ECU 100 and HMI 18 also function as in-vehicle terminals.

[0042] When a vehicle terminal in a parked vehicle 1 receives a reprogramming notification from the server 610, the HMI 18 requests input from the user indicating whether or not they accept the reprogramming. When the HMI 18 receives input indicating acceptance from the user, the vehicle ECU 100 requests reprogramming from the battery ECU 200. Also, when a scan tool 620 containing a new control program (updated version) is connected to the battery ECU 200 of the parked vehicle 1, the scan tool 620 requests reprogramming from the battery ECU 200. These reprogramming requests correspond to program rewriting requests.

[0043] Before program rewriting, the storage device 220 stores a first control program identified by identification information X1. The first control program includes identification information X1 and the program body. The program body includes a control algorithm and various parameters. The control algorithm may include an algorithm for at least one of the charging control and discharging control of the battery 21. The control algorithm may also include an algorithm for state management of the battery 21 (e.g., degradation estimation and degradation suppression).

[0044] When the battery ECU 200 receives a reprogramming request, the battery ECU 200 saves the identification information of the control program before rewriting in S41 of Figure 3. Specifically, as shown in Figure 4, the battery ECU 200 stores the identification information X1 in the memory area of ​​the storage device 220, excluding the area where the control program is written. Subsequently, the battery ECU 200 executes the requested program rewriting (reprogramming) in S42 of Figure 3. The reprogramming erases the first control program stored in the storage device 220, and the second control program identified by the identification information X2 is written to the storage device 220. The second control program is written to the storage device 220 with the identification information X2 and the program body linked together. Each of the identification information X1 and X2 is unique information assigned to each control program. Each of the identification information X1 and X2 may be a program ID (for example, a program part number). Each of the first and second control programs is a control program related to the battery 21 and is executed by the processor 210. However, the content of the program body differs between the first control program and the second control program. For example, functions (controls) may be added or modified by updating the control algorithm through reprogramming.

[0045] Next, in S43 of Figure 3, the battery ECU 200 determines whether the first identification information of the control program before rewriting, saved in S41, matches the second identification information of the control program after rewriting. When the above reprogramming is performed, the identification information and the program body of the control program stored in the storage device 220 are changed. For this reason, if reprogramming is performed, NO is determined in S43 of Figure 3, and the process proceeds to S33. In this case, in S33, the maximum value is set for the distance after SOH update, and in the following S34, the current SOH display value and the maximum value of the distance after SOH update (65535km) are displayed.

[0046] Referring again to Figure 3, if the program rewrite performed in S43 is a program rewrite that does not involve a change in identification information, then S43 is judged as YES and the process proceeds to S37. In this case, the distance after SOH update is updated in S37, and in the following S34, the current SOH display value and the updated distance after SOH update are displayed. An example of a program rewrite that does not involve a change in identification information is the initialization of various user-configurable parameters. Note that the aforementioned SOC lower limit and SOC upper limit are parameters that the user cannot set (change).

[0047] The battery ECU 200 is configured to estimate the degree of degradation of the battery 21 and to control the display device (HMI 18) so that a parameter (SOH display value) indicating the estimated degree of degradation of the battery 21 is displayed. The battery ECU 200 is configured to update the above parameter whenever a predetermined condition (hereinafter referred to as the "update condition") is met. In this embodiment, the processes S14 to S19 in Figure 2 correspond to the process of estimating the degree of degradation of the battery 21. The process S34 in Figure 3 corresponds to the process of displaying the parameter indicating the estimated degree of degradation of the battery 21. The processes S21 and S22 in Figure 2 correspond to the process of updating the above parameter. In this embodiment, after the degree of degradation of the battery 21 is estimated by the processes S14 to S19 in Figure 2, the update condition is met if it is determined to be YES in S20 in Figure 2.

[0048] The battery ECU 200 is configured to display a mileage selected from a first mileage expressed in a predetermined format, a second mileage which is the maximum value in the predetermined format, and a third mileage which is the minimum value in the predetermined format, on the display device. The first mileage is the cumulative mileage traveled by vehicle 1 from the time the above parameters were updated until the present. The first mileage is set as the distance after SOH update in S37 of Figure 3 and displayed in S34 of Figure 3. The second mileage is set as the distance after SOH update in S33 of Figure 3 and displayed in S34 of Figure 3. The third mileage is set as the distance after SOH update in S35 of Figure 3 and displayed in S34 of Figure 3.

[0049] When the control program stored in the storage device 220 is rewritten, the battery ECU 200 determines whether the first identification information of the control program before rewriting matches the second identification information of the control program after rewriting (S43 in Figure 3). If the first identification information and the second identification information match, the battery ECU 200 controls the display device so that the first mileage, expressed in a predetermined format, is displayed (S37 and S34 in Figure 3). On the other hand, if the first identification information and the second identification information do not match, the battery ECU 200 controls the display device so that the second mileage is displayed (S33 and S34 in Figure 3).

[0050] As the cumulative mileage of vehicle 1 increases, the degradation of battery 21 tends to progress. Therefore, the reliability of the SOH display value decreases continuously as the first mileage increases. The battery ECU 200 can inform the user of the reliability according to the mileage by displaying the first mileage along with the SOH display value on the display device. Furthermore, if the control program is rewritten (e.g., reprogrammed) which involves a change in identification information, the reliability of the SOH display value will decrease regardless of the cumulative mileage. For example, the aforementioned SOC lower limit and SOC upper limit may be changed by rewriting the control program. Also, the method for estimating the degree of degradation of battery 21 may be changed by rewriting the control program which involves a change in identification information. Therefore, if the control program is rewritten which involves a change in identification information, the battery ECU 200 will display the second mileage (the maximum value of the displayable mileage) on the display device. This will warn the user that the SOH display value should not be trusted. As described above, by appropriately displaying the parameters that indicate the status of vehicle 1 (SOH display value and distance after SOH update), user convenience can be improved. The adoption of a 16-bit binary format for displaying the mileage makes it easier for users to notice anomalies. In the 16-bit binary format, the minimum value (third mileage) is 0km and the maximum value (second mileage) is 65535km. The first mileage changes within the range of 0km to 65535km.

[0051] Figure 5 shows an example of the operation of the display device (HMI18) according to the display control shown in Figure 3. Referring to Figure 5 in conjunction with Figure 3, the battery ECU200 is configured to control the display device of the HMI18 so that one of the first mileage, second mileage, and third mileage, and the SOH display value are displayed on the same screen. Specifically, initially, S32 is determined to be YES, and the processes of S33 and S34 are executed. As a result, the display device displays, for example, screen Sc1. Screen Sc1 includes the initial value M11 of the SOH display value and the second mileage M21. Subsequently, when the SOH display value is updated, S31 is determined to be YES, and the processes of S35 and S34 are executed. As a result, the display device displays, for example, screen Sc2. Screen Sc2 includes the current value M12 of the updated SOH display value and the third mileage M22. The third mileage M22 indicates that the current value M12 of the displayed SOH display value has high reliability. When the SOH display value is updated, the third mileage M22 is displayed, making it easier for the user to understand the exact degree of battery degradation 21. Subsequently, when vehicle 1 starts moving, processes S37 and S34 are executed. As a result, the first mileage M23 is displayed on screen Sc2 instead of the third mileage M22.

[0052] In this embodiment, the rewriting of the control program involving a change in identification information (for example, the reprogramming described above) is performed when vehicle 1 is not in motion. Therefore, while vehicle 1 is in motion, the distance since SOH update is updated sequentially in S37, and the first mileage M23 on screen Sc2 is also updated sequentially. However, when the distance since SOH update reaches its maximum value (65535km), the distance since SOH update stops increasing and is maintained at its maximum value. Also, when the SOH display value is updated, the display device displays screen Sc2 again, including the current value M12 of the updated SOH display value and the third mileage M22.

[0053] When the control program in the battery ECU200 is rewritten, which involves a change in identification information, processes S33 and S34 are executed. As a result, the display device displays, for example, screen Sc3. Screen Sc3 includes the current value M12 of the SOH display value and the second mileage M21. Subsequently, when the SOH display value is updated, the display device displays screen Sc2 again, which includes the updated current value M12 of the SOH display value and the third mileage M22.

[0054] The parameter indicating the degree of battery degradation 21 is not limited to the net value of the capacity retention rate. For example, the battery ECU 200 may set the gross value of the capacity retention rate estimated in S19 of Figure 2 directly as the SOH display value. Alternatively, the display device (HMI 18) may display the estimated capacity of the degraded battery 21 (C1) and the capacity of the battery 21 in its initial state (C0) on the same screen. Furthermore, the internal resistance value of the battery 21 may be used instead of the capacity retention rate.

[0055] The configurations of the vehicle body and battery pack shown in Figure 1 can be modified as appropriate. In the above embodiment, the battery ECU 200 indirectly controls the HMI 18 (display device) via the vehicle ECU 100. However, it is not limited to this, and the battery ECU 200 may be configured to directly control the HMI 18 (display device). Alternatively, the functions of the battery ECU 200 may be implemented in the vehicle ECU 100. The vehicle ECU 100 may estimate the degree of degradation of the battery 21 based on the information obtained from the battery ECU 200. The vehicle is not limited to a passenger car, but may be a bus, truck, or work vehicle (tractor, forklift, etc.).

[0056] 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 description of the embodiments above, and all modifications within the meaning and scope equivalent to the claims are intended to be included. [Explanation of Symbols]

[0057] 1 vehicle, 10 car bodies, 20 battery packs, 21 batteries, 200 battery ECUs.

Claims

1. A vehicle comprising a battery, a display device, and a control device, The control device comprises a storage device for storing a control program relating to the battery, and a processor for executing the control program. The control device is configured to estimate the degree of degradation of the battery and to control the display device so that a parameter indicating the estimated degree of degradation is displayed. The control device is When the control program is rewritten, it is determined whether the first identification information of the control program before rewriting matches the second identification information of the control program after rewriting. If the first identification information and the second identification information match, the display device is controlled to display the first mileage expressed in a predetermined format. If the first identification information and the second identification information do not match, the display device is configured to be controlled so that the second mileage is displayed. The first mileage is the cumulative mileage traveled by the vehicle after the parameter update. A vehicle in which the second mileage is the maximum value in the predetermined form.

2. The control device is configured to update the parameters each time a predetermined condition is met. The control device is configured to control the display device so that the third mileage is displayed when the parameter is updated. The vehicle according to claim 1, wherein the third mileage is the minimum value in the predetermined form.

3. The control device is configured to control the display device so that one of the first mileage, the second mileage, and the third mileage, and the parameter are displayed on the same screen. The vehicle according to claim 2, wherein the control device is configured to update the parameters on the screen based on the latest estimated value of the degree of deterioration.

4. The vehicle is configured to be able to run using the power output from the battery, The aforementioned predetermined format is a 16-bit binary format. The vehicle according to any one of claims 1 to 3, wherein the second mileage is 65,535 km.

5. The vehicle is equipped with an energy storage device including the battery and the control device, The aforementioned parameter is the capacity retention rate. The control device is configured to control the State of Control (SOC) of the battery within a range from the lower limit of SOC to the upper limit of SOC. The vehicle according to any one of claims 1 to 3, wherein the control device is configured to estimate the capacity of the battery from the lower limit of the SOC to the upper limit of the SOC, and to calculate the capacity retention rate based on the estimated capacity.

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