Electric vehicle control device, electric vehicle and control method therefor

Abstract

To achieve life elongation of a battery in an electric vehicle which can change a degree of operator intervention concerning vehicle travel.SOLUTION: In an electric vehicle which travels by using a battery where electric goes in and out, it is determined that an operation mode of the vehicle is either a first operation mode in which a degree of operator intervention in vehicle operation is low or a second operation mode in which a degree of operator intervention is higher than the first operation mode. When it is determined that the operation mode is the first operation mode, an upper limit of a quantity of electricity going in and out the battery per unit time is set to a first upper limit amount lower than a second upper limit that is set in the second operation mode. Furthermore, a quantity of electricity going in and out the battery is controlled in a range that does not exceed the first upper limit amount or the second upper limit amount set according to the operation mode.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a control device for an electric vehicle equipped with a battery, an electric vehicle, and a control method thereof. [Background technology]

[0002] For battery-equipped vehicles, technologies have been proposed to suppress the deterioration of the battery's lifespan. For example, the following Patent Document 1 discloses a technology that uses a battery containing multiple cells, has a configuration for switching the cells connected to a load, and further relaxes the output limit of the battery when a predetermined condition is met. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2012-120372 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, when trying to suppress the deterioration of the battery life, it is considered that the driving mode in which the vehicle equipped with the battery is driven becomes an issue. This is because, depending on the driving mode, the output demand on the battery when driving the motor with the power stored in the battery and the input demand on the battery when charging the battery with regenerative power may differ. Driving modes that may affect the battery life in a vehicle that runs using such a battery include, for example, an auto-cruise driving mode in which the auto-cruise is on, a following driving mode in which the vehicle follows the vehicle in front, an automatic driving mode in which the driver's involvement is not assumed, and a normal driving mode in which the driver is in charge (hereinafter, manual mode). There is still room for consideration regarding suppression of the deterioration of the battery life due to such driving modes. [Means for solving the problem]

[0005] The present disclosure can be realized in the following forms or application examples.

[0006] (1) A first aspect of the present disclosure is a control device for an electric vehicle that runs using a battery that receives and outputs electric power. The electric vehicle control device includes a driving mode determination unit that determines whether the driving mode of the vehicle is a first driving mode, which is one of two driving modes with different degrees of driver involvement in the driving of the vehicle, or a second driving mode with a higher degree of driver involvement than the first driving mode, an upper limit setting unit that sets an upper limit of the amount of electricity per unit time that flows into and out of the battery to a first upper limit amount that is lower than a second upper limit amount that is an upper limit set in the second driving mode when the driving mode is determined to be the first driving mode, and a battery control unit that controls the amount of electricity that flows into and out of the battery within a range that does not exceed the first upper limit amount or the second upper limit amount according to the driving mode. In this way, the upper limit of the amount of electricity that flows into and out of the battery in the first driving mode, in which the degree of driver involvement in the driving of the vehicle is low, i.e., the more autonomous driving side, can be made lower than the upper limit of the amount of electricity that flows into and out of the battery in the second driving mode, in which the driving mode is not more autonomous, thereby suppressing a rise in the temperature of the battery. As a result, the battery life can be extended. (2) In the above configuration, the upper limit setting unit may set an upper limit for at least one of the charge amount and the discharge amount of the battery as the upper limit of the amount of electricity, and a charge change width, which is a change width of the charge amount from the second upper limit amount to the first upper limit amount, may be smaller than a discharge change width, which is a change width of the discharge amount from the second upper limit amount to the first upper limit amount. Since the temperature of the battery, which affects the life of the battery, depends on the internal resistance value of the battery and the current flowing in and out of the battery, it is meaningful to limit the upper limit amounts of both charge and discharge, but since charging of the battery is expected to occur when the vehicle decelerates and regenerative braking by the electric motor is used, making the charge change width smaller than the discharge change width reduces the constraints on regenerative braking and is less likely to affect the drivability of the vehicle. (3) In each of the above configurations, the charge amount change width may be set to zero. In this way, the amount of electricity input to the battery is not limited, and the effect on drivability can be minimized. (4) In each of the above configurations, a detection unit may be provided for detecting a usage condition of the battery, and the upper limit setting unit may further reduce the first upper limit amount when it determines that the detected usage condition corresponds to a predetermined usage condition that may cause a decrease in the life of the battery. In this way, the decrease in the life of the battery can be further suppressed. (5) In each of the above configurations, the usage conditions may include at least one of the temperature and the accumulated usage time of the battery, and the predetermined conditions may be that the temperature of the battery is equal to or greater than a predetermined temperature, and that the accumulated usage time of the battery is equal to or greater than a predetermined accumulated time. Since the temperature and the accumulated usage time of the battery are highly correlated with the life of the battery, detecting at least one of them and reducing the first upper limit amount can further extend the life of the battery. (6) In each of the above configurations, the vehicle may be a battery-powered electric vehicle that runs on the power of the battery, and may further include a speed control unit that limits the maximum vehicle speed of the vehicle to thereby limit the amount of discharge of the battery. In this way, the vehicle speed can be limited, and excessive load is not placed on the battery, thereby further extending the life of the battery. (7) In each of the above configurations, a switch that can be set by an occupant of the vehicle may be provided, and the battery control unit may cause the speed control unit to limit the maximum speed when the driving mode of the vehicle is the first driving mode and the switch is set to ON. This allows the occupant to further extend the life of the battery at their own will. (8) In each of the above configurations, the first driving mode may be an automatic driving mode in which the vehicle is driven without the involvement of the driver, and the second driving mode may be a manual driving mode in which the vehicle is driven with the involvement of the driver. In this way, since the vehicle is driven in automatic driving without the involvement of the driver, it is possible to prioritize the long life of the battery. (9) The present disclosure includes not only the electric vehicle control device described above, but also an electric vehicle including each component of the electric vehicle control device, and a method for controlling the electric vehicle. In any of the above aspects, the inverter that exchanges power between the battery and the electric motor is controlled to extend the life of the battery in the first driving mode, in which the degree of driver involvement in the running of the vehicle is lower than in the second driving mode. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic configuration diagram of a vehicle used in each embodiment. [Diagram 2] FIG. 2 is an explanatory diagram showing the configuration of an electrical system in each embodiment. [Diagram 3] 5 is a flowchart showing an outline of an electricity amount limiting process routine in the first embodiment. [Figure 4] FIG. 4 is an explanatory diagram illustrating the relationship between the level of autonomous driving and electric quantity control in the first embodiment. [Diagram 5] FIG. 11 is an explanatory diagram showing an example of limiting the amount of electricity. [Figure 6] 10 is a flowchart showing an outline of an electricity amount limiting process routine in a second embodiment. [Figure 7] FIG. 11 is an explanatory diagram illustrating the relationship between the level of autonomous driving and electric quantity control in the second embodiment. [Figure 8] FIG. 11 is an explanatory diagram showing an example of limiting the amount of electricity. [Figure 9] 10 is a flowchart showing another example of the configuration of the electricity amount limiting process routine. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] A. First embodiment: (A1) Vehicle configuration: The electric vehicle control device of the first embodiment is incorporated in the vehicle AM, so the configuration of the vehicle AM ​​will be described first. The vehicle AM ​​is capable of multiple levels of automatic driving in addition to normal driving (manual driving) by the driver. Specifically, the vehicle AM ​​can achieve automatic driving levels (0 to 5) including manual driving (level 0). Such automatic driving is realized by the electric vehicle control device 200. The electric vehicle control device 200 includes an automatic driving ECU 100 that achieves automatic driving at a specified level 4 or 5 according to a route instruction from a route guidance device 110 that guides the route to the destination. The vehicle AM ​​is provided with a steering wheel 151 as well as an accelerator pedal and a brake pedal (not shown), and the driver can drive the vehicle (level 0), drive with driving assistance (levels 1 to 2), or intervene in the automatic driving by the automatic driving ECU 100 (level 3). Note that the part that controls such automatic driving may be separated as a vehicle driving device, and only the part that controls the charging and discharging of the battery in the electric vehicle, which will be described later, may be configured as the electric vehicle control device.

[0009] The electric vehicle control device 200 includes many devices such as the automatic driving ECU 100 and route guidance device 110 described above, as well as a power control force ECU 120, an electric motor 130, a steering ECU 140, and a steering device 150. These ECUs and devices are connected by a network CAN, which is an in-vehicle LAN (not shown), and constantly exchange data and commands. The automatic driving ECU 100 is connected to an instruction unit 105 that includes a switch for setting the level of automatic driving and a protection switch 106 for setting a protection mode (described later) on / off. The instruction unit 105 may be provided on an instrument panel or the like, or may be configured as a wireless terminal and send instructions to the automatic driving ECU 100 via the wirelessly connected network CAN.

[0010] The power control ECU 120 controls the driving force and braking force for driving the vehicle AM. The driving force ECU 120 receives instructions from the automatic driving ECU 100 and controls the driving power for driving the electric motor 130 and the regenerative power during braking. The electric motor 130 exchanges power with the battery pack 40 described later via a power control unit (hereinafter referred to as PCU) having an inverter. The power control ECU 120 directly controls this inverter. The electric system including the inverter will be described later. The driving force generated when the electric motor 130 receives the supply of electric power and rotates is transmitted to the right and left rear wheels 11 and 12 via a transmission 132 including a differential gear and a drive shaft 134. In this embodiment, the vehicle is rear-wheel drive, but may be front-wheel drive or four-wheel drive. The vehicle AM ​​of the first embodiment has a configuration as a so-called electric vehicle.

[0011] The steering device 150 includes an encoder 152 that detects the steering amount (rotation angle) of the handle 151, and a steering motor 154 that drives a steering gear 155. The steering motor 154 of the steering device 150 controls the steering angle (angle with respect to the straight ahead direction) of the right and left front wheels 13, 14 via the steering gear 155. The steering gear 155 imparts a turning radius to each of the right and left front wheels 13, 14 as necessary.

[0012] Next, a mechanism for applying braking force to each wheel 11-14 will be described. As already explained, the rear wheels 11, 12 obtain braking force by the electric motor 130 regenerating electric power, but each wheel 11-14, including the rear wheels 11, 12, is provided with a configuration capable of applying braking force using hydraulic pressure. As shown in FIG. 1, the wheels 11-14 are provided with a disc brake device including a brake disc BD and wheel cylinders 19-22, etc., and the braking force of each wheel can be controlled using hydraulic pressure supplied via a hydraulic piping system 10. The brake disc BD provided on each wheel 11-14 is structured to be sandwiched between disc pads (not shown) attached to the wheel cylinders 19-22, and generates braking force by friction between the disc pads and the brake discs. The braking force required for the vehicle AM ​​during autonomous driving is calculated by the electric vehicle control device 200, and if the braking force obtained by the regeneration of power by the electric motor 130 is sufficient, regenerative braking is prioritized, and if the braking force obtained by the regenerative braking is insufficient, the insufficient braking force is supplemented by the brake disc BD. The hydraulic pressure that drives the wheel cylinders 19-22 to obtain the required braking force is controlled by the power control ECU 120.

[0013] (A2) Electrical configuration: 2 is an explanatory diagram showing an electrical system in the vehicle AM. As shown in the figure, the vehicle AM ​​includes a power control unit (hereinafter referred to as PCU) 30 that controls the input and output of electric power to and from an electric motor 130, a battery pack 40 that stores electric power, an auxiliary battery 55 that supplies DC power to a DC auxiliary 57 that operates on DC, and an auxiliary inverter 62 that supplies AC power to an AC auxiliary 65 that operates on AC.

[0014] The battery pack 40 includes a main battery 41, which is a secondary battery, an ACR 45 that controls the charging current, and a system master relay (hereinafter referred to as SMR) 47. The ACR 45 is connected to an external AC charger 51. The main battery 41 in this embodiment is configured by connecting multiple battery cells, n in number, in series, which are further connected in parallel, m in number. Therefore, the internal resistance r of the main battery 41 is calculated as the sum of the internal resistances R of the respective battery cells in series and parallel, using the following equation (1): r = (R × n) / m … (1) The amount of heat CJ generated inside the main battery 41 is proportional to the square of the current I output from or input to the main battery 41, as shown in the following equation (2). CJ = r × I 2 …(2)

[0015] The AC charger 51 is connected to a charging connector 52 that is connected to an external AC power source, and when the AC power source is connected to the charging connector 52, the main battery 41 is charged via the ACR 45. Here, the charging is performed using the AC power source, but a DC charger may be prepared and connected to an external DC power source to charge the main battery 41 via the DCR. The energy required for the vehicle AM ​​to run and for various electric devices is basically provided by the power stored in the main battery 41 of the battery pack 40. The SMR 47 is inserted in the output path from the main battery 41 and turns the main current on and off. When an IG switch (not shown) is turned on, the SMR 47 is turned on (connected state), and the DC current from the battery pack 40 is supplied to the PCU 30 and the like. The path that connects the main battery 41 and the PCU 30 via the SMR 47 may be called a main power line MPL.

[0016] The PCU 30 includes an inverter 32 and a DC-DC converter (hereinafter, referred to as DDC) 35. The inverter 32 operates upon receiving an instruction from a power control ECU 120 included in the electric vehicle control device 200. The power control ECU 120 controls the inverter 32 to supply DC power received from the battery pack 40 via the main power line MPL as three-phase AC to the electric motor 130, thereby running the vehicle AM. On the other hand, during braking, the power regenerated by the electric motor 130 is converted to DC and supplied to the battery pack 40 via the main power line MPL to charge it. An auxiliary battery 55, which is another secondary battery provided in the vehicle AM, functions as a DC power source for operating various ECUs and DC auxiliary devices 57 included in the electric vehicle control device 200. The auxiliary battery 55 is connected to the main power line MPL via the DDC 35, and is charged via the DDC 35 when the charge level of the auxiliary battery 55 decreases.

[0017] (A3) Battery Control: Next, the electricity quantity control process in the battery pack 40 will be described with reference to FIG. 3. The electricity quantity control process routine shown in the figure is an example of a process executed by the power control ECU 120 through communication with the automatic driving ECU 100. When the power control ECU 120 starts operation, it repeatedly executes this electricity quantity control process. The power control ECU 120 first communicates with the automatic driving ECU 100 and executes a process to acquire the driving mode (step S111). The driving mode is the automatic driving mode performed by the automatic driving ECU 100, and is generally expressed as level 0 to level 5. Note that when the vehicle is not automatically driven, that is, when the vehicle is manually driven, the power control ECU 120 acquires a value indicating that the driving mode is manual driving from the automatic driving ECU 100.

[0018] Next, it is determined whether the acquired driving mode is the first driving mode or the second driving mode (step S112). This process corresponds to the driving mode determination unit. Here, the first driving mode is a driving mode in which the degree of the driver's involvement in the running of the vehicle is low, and the second driving mode is a driving mode in which the degree of the driver's involvement is higher than that of the first driving mode. That is, the first driving mode indicates a higher level of automatic driving than the second driving mode. In this embodiment, automatic driving level 4 or 5 is the first driving mode, and automatic driving level 3 or lower is the second driving mode, but the classification of the two may be set to other than this. For example, automatic driving level 3 or higher may be the first driving mode, and level 5 or higher may be the first driving mode. The driving mode may be determined by determining whether a threshold value is set in advance and whether the threshold value is large or small. For example, any of levels 0 to 2 may be set as the threshold value, and any level higher than that may be set as the first driving mode. Note that level 0 means a state in which there is no intervention from the automatic driving ECU 100 in the driver's driving itself, that is, a manual driving mode.

[0019] When it is determined in step S112 that the driving mode is the first driving mode, a process is performed to set the upper limit of the amount of electricity input / output to / from the main battery 41 of the battery pack 40 to a first upper limit amount (step S121). On the other hand, when it is determined in step S112 that the driving mode is the second driving mode, a process is performed to set the upper limit of the amount of electricity input / output to / from the main battery 41 of the battery pack 40 to a second upper limit amount (step S122). These processes correspond to the upper limit setting unit. A combination of upper limit amounts set in this embodiment is shown in FIG. 4. As shown in the figure, if the driving mode is the first driving mode, that is, level 3 or higher of the automatic driving, the upper limit of the output electric amount Wout taken from the main battery 41 is set to the first upper limit amount OL1. Also, if the driving mode is the second driving mode, that is, level 2 or lower of the automatic driving, the upper limit of the output electric amount Wout taken from the main battery 41 is set to the default setting value, that is, the second upper limit amount OL2. The upper limit of the input electricity amount Win input to the main battery 41, that is, used for charging, remains at the second upper limit amount IL2 set as the default.

[0020] After executing the above-mentioned upper limit amount setting process (step S121 or S122), the power control ECU 120 performs battery control within the set upper limit amount range (step S131). This process corresponds to the battery control unit. Battery control within the upper limit amount range will be described with reference to FIG. 5. The vertical axis of FIG. 5 indicates the amount of electricity flowing in and out of the main battery 41, which is a battery, and the upper side from the origin indicates the output amount of electricity Wout taken out from the main battery 41, and the lower side indicates the input amount of electricity Win used to charge the main battery 41. Here, the amount of electricity may be the amount of power or the amount of current per hour. In the figure, the first upper limit amount OL1 and the second upper limit amount OL2 are shown for the output amount of electricity, and the second upper limit amount IL2 is shown for the input amount of electricity. Here, the second upper limit amount OL2 on the output side and the second upper limit amount IL2 on the input side are default upper limits of the main battery 41, and indicate so-called rated amounts. In contrast, the first upper limit amount OL1 on the output side indicates an upper limit of the amount of electricity input to and output from the main battery 41 when the driving mode is the first driving mode, that is, when the autonomous driving is at level 3 or higher.

[0021] Each of the upper limit amounts OL1, OL2, IL2 takes a constant value when the vehicle speed V is equal to or lower than a predetermined value. When the vehicle speed V is equal to or lower than a predetermined value, the upper limit amount OL1 of the amount of electricity output from the main battery 41 is the amount of electricity Wo1, the upper limit amount OL2 is the amount of electricity Wo2, and the upper limit amount IL2 of the amount of electricity input to the main battery 41 is the amount of electricity Wi2. The difference between the amount of electricity Wo2, which is the upper limit amount on the output side, and the amount of electricity Wo1 corresponds to the discharge fluctuation width ΔWo. The upper limit amounts OL1, OL2, IL2 are designed to gradually decrease as the vehicle speed V increases. This is to prevent an excessive temperature rise in the main battery 41, since the temperature of the main battery 41 has risen during the running of the vehicle AM ​​up to that point when the vehicle speed V is high.

[0022] The electric vehicle control device 200 of the first embodiment described above is capable of driving from manual driving of levels 0 to 2 to driving with driving assistance (second driving mode) and automatic driving of level 3 or higher (first driving mode), and the upper limit of the amount of electricity output from the main battery 41 can be varied according to the driving mode, thereby suppressing heat generation from the main battery 41. In the first driving mode, the acceleration of the vehicle AM ​​is controlled by the automatic driving ECU 100, so that driving is not hindered even if the upper limit of the amount of electricity output from the main battery 41 is lowered. In the automatic driving mode, rapid acceleration exceeding a predetermined acceleration is not performed, so that the upper limit of the amount of electricity output from the main battery 41 can be lowered to suppress heat generation from the main battery 41, and as a result, the driving life can be extended. Here, the amount of electricity may be a power value or a current value, and if the upper limit of the current value I is lowered, the heat generation amount CJ is suppressed as shown in the above-mentioned formula (2). The upper limit of the amount of electricity may be limited as a power value, or the amount of electricity may be limited by limiting the number of battery cells used in the main battery 41, which has many battery cells connected in series and parallel. In this case, changing the combination of battery cells used reduces the average operating rate per battery cell, which contributes to a longer life.

[0023] B. Second embodiment: Next, an electric vehicle control device 200 and a vehicle AM ​​equipped with the same will be described as a second embodiment. The hardware configurations of the electric vehicle control device 200 and the vehicle AM ​​of the second embodiment are substantially similar to those of the first embodiment. The second embodiment differs in the content of the electricity amount limiting process. An outline of the electricity amount limiting process routine in the second embodiment is shown in FIG. 6. The routine shown in the figure differs from the first embodiment in that steps S125 to S127 are added between steps S121 and S131.

[0024] This electricity amount limiting process routine is started, and similarly to the first embodiment, the first upper limit amount or the second upper limit amount is set according to the acquired driving mode (steps S111, S112), and then the vehicle speed V is acquired from the automatic driving ECU 100 (step S125). Next, the state of the protection switch 106 provided in the instruction unit 105 is read (step S126), and if the protection switch 106 is on (step S126: "YES"), a vehicle speed limit is added to the first upper limit amount of the electricity amount output from the main battery 41 (step S127). Then, the amount of electricity flowing in and out of the main battery 41 is controlled according to the set limit (step S131).

[0025] The relationship between the level of automatic driving and the control of the amount of electricity in the second embodiment is shown in FIG. 7, and an example of the control of the amount of electricity in this case is shown in FIG. 8. As shown in FIG. 7, in the second embodiment, upper limits are set for three items: the amount of electricity Wout output from the main battery 41, the amount of electricity Win input to the main battery 41, and the state of the protection switch 106. In the second embodiment, the criteria for determining these three items are different depending on the driving mode, etc. The amount of electricity Wout output from the main battery 41 is set to a second upper limit OL2 if the driving mode is an automatic driving level 0 to 2, and is set to a first upper limit OL1 if the driving mode is an automatic driving level 3 to 5. In addition, the amount of electricity Win input to the main battery 41 is set to a second upper limit IL2 if the driving mode is an automatic driving level 0 to 3, and is set to a first upper limit IL1 if the driving mode is an automatic driving level 4 to 5. On the other hand, regarding the state of the protection switch 106, if the autonomous driving level is 4 or 5 and the protection switch 106 is on, a limit OLv based on the vehicle speed, etc. is set, but in other cases, a limit OLv based on the vehicle speed, etc. is not set.

[0026] The above settings are summarized in FIG. 8. As shown in the figure, if the vehicle speed is not limited and the vehicle speed V is equal to or lower than a predetermined value, the upper limit amounts OL1, OL2, IL1, and IL2 take constant values. At this time, the upper limit amount OL1 of the amount of electricity output from the main battery 41 is the amount of electricity Wo1, the upper limit amount OL2 is the amount of electricity Wo2, the upper limit amount IL1 of the amount of electricity input to the main battery 41 is the amount of electricity Wi1, and the upper limit amount IL2 is the amount of electricity Wi2. The difference between the amount of electricity Wo2, which is the upper limit amount on the output side, and the amount of electricity Wo1 corresponds to the discharge fluctuation width ΔWo, and the difference between the amount of electricity Wi2, which is the upper limit amount on the input side, and the amount of electricity Wi1 corresponds to the charge fluctuation width ΔWi. In the second embodiment, the charge fluctuation width ΔWi is set smaller than the discharge fluctuation width ΔWo. For this reason, regeneration is less likely to be limited by the electric motor 130 required for braking, and the impact on the drivability of the vehicle AM ​​is small. The charge fluctuation width ΔWi may be a value of 0. As in the first embodiment, the charge fluctuation width ΔWi being 0 is equivalent to keeping the upper limit of the amount of electricity input to the main battery 41 constant regardless of the level of autonomous driving.

[0027] Furthermore, if the protection switch 106 of the instruction unit 105 is turned on, a limit OLv based on the speed or the like is applied to the amount of electricity output from the main battery 41. Therefore, if the driver turns on the protection switch 106 during automatic driving (level 4 or 5), and the vehicle speed V is equal to or higher than the threshold value Vth, the amount of electricity output from the main battery 41 is largely limited, thereby suppressing a rise in temperature of the main battery 41 and extending the life of the main battery 41. Note that, in the second embodiment, as in the first embodiment, the upper limit amounts OL1, OL2, IL1, and IL2 have the characteristic of gradually decreasing as the vehicle speed V increases.

[0028] According to the second embodiment described above, in addition to achieving the same effects as the first embodiment, the upper limit of the amount of electricity input to the main battery 41 can be reduced when the driving mode involves little driver involvement, thereby extending the life of the main battery 41. Also, when the driver turns on the protection switch 106 and intentionally selects the protection mode, restrictions can be imposed based on the vehicle speed, etc., further protecting the main battery 41 and extending its life.

[0029] In the second embodiment, in order to protect the battery and extend its life, the upper limit of the amount of electricity is set based on the degree of the driver's involvement, and the vehicle speed is also limited. However, such a limit may be similarly set if the conditions of use are such that the battery life may be reduced. Such conditions of use include the temperature of the battery itself, the temperature or humidity of the environment in which the battery is used, the vibration applied to the battery, the number of charge / discharge cycles when the battery is used, the accumulated use time of the battery, and a parameter indicating the deterioration of the electrolyte inside the battery. The temperature of the battery may be detected by a temperature sensor provided in the battery, and the humidity may be detected by a humidity sensor. Alternatively, the temperature and humidity data of the location of the vehicle AM ​​may be acquired by an external site, such as the Japan Meteorological Agency or Weathernews site, via communication. The vibration applied to the battery can be easily detected by an acceleration sensor or the like. The number of charge / discharge cycles when the battery is used, or the accumulated use time of the battery, can be obtained by a dedicated CPU or the like provided in the battery pack 40. The detection unit may detect one of these, or may detect a combination of these. This can then be used in conjunction with setting an upper limit on the amount of electricity flowing in and out of the battery per unit time, based on the driver's level of involvement in the vehicle's operation.

[0030] An example of the process for limiting the amount of electricity based on such usage conditions is shown in FIG. 9. The illustrated electricity amount limiting process routine is substantially similar to that shown in FIG. 6 described in the second embodiment. Instead of steps S125 to S127 in the second embodiment, steps S225 to S227 are executed in the third embodiment. Specifically, after setting the first upper limit amount or the second upper limit amount that limits the amount of electricity input to or output from the main battery 41 in step S121 or S122, a process is performed to obtain usage conditions that affect the shortening of the battery life from the sensor 90. Here, the sensor 90 is the above-mentioned temperature sensor or a detector that detects the accumulated usage time, or the like.

[0031] After acquiring the usage conditions, it is determined whether the usage conditions are equal to or greater than a threshold (step S226). For example, it is determined whether the temperature of the main battery 41 is equal to or greater than a predetermined threshold, or whether the accumulated usage time of the main battery 41 is equal to or greater than a predetermined threshold. If it is equal to or greater than the threshold, that is, if it is determined that the usage conditions are such that there is a concern that the battery life may be reduced, a limit is imposed on the amount of electricity used (step S227), similar to the vehicle speed limit in the second embodiment. This limit may be, similar to the vehicle speed limit, such that the upper limit of the amount of electricity output from the main battery 41 is lowered as the battery temperature increases or the accumulated usage time increases.

[0032] In some of the embodiments described above, the vehicle AM ​​is an electric vehicle that runs on battery power alone, but the present invention can also be applied to other vehicles that use batteries, such as fuel cell vehicles that run on a combination of a fuel cell and a battery, plug-in hybrid vehicles, and hybrid vehicles that run on a combination of a prime mover and a battery.

[0033] The amount of electricity flowing in and out of the battery may be either the amount of power or the current value. The upper limit may be set for either the amount of electricity output from the battery, i.e., the discharge side, or the amount of electricity input, i.e., the charge side. The charge change width ΔWi and the discharge change width ΔWo may be specified as the absolute value of the charge amount or discharge amount, or may be specified as the rate of change. In the case of autonomous driving, the degree of the driver's involvement in the running of the vehicle can be determined using the autonomous driving levels 0 to 5 as described above, but may be determined by other criteria. For example, the first driving mode may be determined when the auto cruise is on, and the second driving mode may be determined when the auto cruise is off. The first driving mode may be determined when the following driving mode that follows the vehicle in front is on, and the second driving mode may be determined when the auto cruise is off.

[0034] In each of the above embodiments, a part of the configuration realized by hardware may be replaced by software. At least a part of the configuration realized by software may be realized by a discrete circuit configuration. In addition, when a part or all of the functions of the present disclosure are realized by software, the software (computer program) can be provided in a form stored in a computer-readable recording medium. The term "computer-readable recording medium" is not limited to portable recording media such as flexible disks and CD-ROMs, but also includes internal storage devices in a computer such as various RAMs and ROMs, and external storage devices fixed to a computer such as a hard disk. In other words, the term "computer-readable recording medium" has a broad meaning including any recording medium to which a data packet can be fixed, not temporarily.

[0035] The present disclosure is not limited to the above-mentioned embodiment, and can be realized in various configurations without departing from the spirit of the present disclosure. For example, the technical features in the embodiments corresponding to the technical features in each aspect described in the Summary of the Invention column can be appropriately replaced or combined to solve some or all of the above-mentioned problems or to achieve some or all of the above-mentioned effects. Furthermore, if the technical feature is not described as essential in this specification, it can be appropriately deleted. [Explanation of symbols]

[0036] AM...vehicle, BD...brake disc, CAN...network, 10...hydraulic piping system, 11,12...rear wheels, 13,14...front wheels, 19-22...wheel cylinder, 30...PCU, 32...inverter, 40...battery pack, 41...main battery, 45...ACR, 47...SMR, 51...AC charger, 52...charging connector, 55...auxiliary battery, 57...DC auxiliary, 62...auxiliary inverter, 65...AC auxiliary, 105...indicator, 106...protective switch, 100...autonomous driving ECU, 110...route guidance device, 120...power control ECU, 130...electric motor, 132...transmission, 134...drive shaft, 140...steering ECU, 150...steering device, 151...handle, 152...encoder, 154...steering motor, 155...steering gear, 200...electric vehicle control device

Claims

1. A control device for an electric vehicle that runs using a battery that inputs and outputs electric power, a driving mode determination unit that determines whether a driving mode of the vehicle is a first driving mode, which is one of two driving modes having different degrees of driver involvement in driving of the vehicle, or a second driving mode, which has a higher degree of driver involvement than the first driving mode; an upper limit setting unit that sets, when the operation mode is determined to be the first operation mode, an upper limit of an amount of electricity per unit time flowing into and out of the battery to a first upper limit amount that is lower than a second upper limit amount that is an upper limit set in the second operation mode; a battery control unit that controls the amount of electricity flowing into and out of the battery within a range not exceeding the first upper limit amount or the second upper limit amount according to the operation mode; An electric vehicle control device comprising:

2. The upper limit setting unit is As the upper limit of the amount of electricity, an upper limit of at least one of a charging amount and a discharging amount of the battery is set, a charge change width, which is a change width of the charge amount from the second upper limit amount to the first upper limit amount, is smaller than a discharge change width, which is a change width of the discharge amount from the second upper limit amount to the first upper limit amount; The electric vehicle control device according to claim 1.

3. The electric vehicle control device according to claim 2 , wherein the charge change width is zero.

4. a detection unit for detecting a usage condition of the battery; the upper limit setting unit further reduces the first upper limit amount when it determines that the detected usage condition corresponds to a predetermined usage condition in which a reduction in the life of the battery is a concern. The electric vehicle control device according to claim 1 .

5. 5. The vehicle control device according to claim 4, wherein the usage conditions include at least one of a temperature and an accumulated usage time of the battery, and the predetermined conditions are that the temperature of the battery is equal to or higher than a predetermined temperature and that the accumulated usage time of the battery is equal to or higher than a predetermined accumulated time.

6. the vehicle is a battery-powered electric vehicle that runs on power from the battery, The control device for an electric vehicle according to claim 1 , further comprising: a limiting unit that limits a maximum vehicle speed of the vehicle to thereby limit a discharge amount of the battery.

7. a switch that can be set by an occupant of the vehicle; The battery control unit limits the maximum speed when the driving mode of the vehicle is the first driving mode and the switch is set to on. The electric vehicle control device according to claim 6.

8. 8. The electric vehicle control device according to claim 1, wherein the first driving mode is an automatic driving mode in which the vehicle is driven without involvement of the driver, and the second driving mode is a manual driving mode in which the vehicle is driven with involvement of the driver.

9. A battery; an electric motor that is driven by the electric power of the battery to output power when the vehicle is traveling and that regenerates electric power when the vehicle is braking; an inverter that transfers electric power between the battery and the electric motor; A driving control unit that drives the vehicle in a first driving mode, which is one of two driving modes having different degrees of driver involvement in driving of the vehicle, or a second driving mode in which the degree of driver involvement is higher than that of the first driving mode; an upper limit setting unit that sets, when a drive mode of the vehicle is the first drive mode, an upper limit of an amount of electricity per unit time flowing into and out of the battery to a first upper limit amount that is lower than a second upper limit amount that is an upper limit set in the second drive mode; a battery control unit that controls the inverter so that the amount of electricity flowing into and out of the battery does not exceed the first upper limit amount or the second upper limit amount that is set according to an operation mode; An electric vehicle equipped with

10. 11. The electric vehicle according to claim 10, wherein the first driving mode is an automated driving mode in which the vehicle is driven without involvement of the driver, and the second driving mode is a manual driving mode in which the vehicle is driven with involvement of the driver.

11. When the vehicle is traveling, the battery power is output to the electric motor via the inverter, and the electric motor outputs power for traveling the vehicle. When braking the vehicle, electric power generated by the electric motor using at least a part of the braking force is regenerated via the inverter; The vehicle is driven in a first driving mode, which is one of two driving modes having different degrees of driver involvement in driving of the vehicle, or in a second driving mode in which the degree of driver involvement is higher than that of the first driving mode; When a drive mode of the vehicle is the first drive mode, an upper limit of an amount of electricity per unit time flowing into and out of the battery is set to a first upper limit amount that is lower than a second upper limit amount that is an upper limit set in the second drive mode, controlling the inverter so that the amount of electricity flowing in and out of the battery is lower than the first upper limit amount or the second upper limit amount set according to an operation mode; A method for controlling an electric vehicle.

Images