Energy management device for vehicle

Abstract

To more surely prevent power shortage even when at least one on-vehicle system continuously executes a stop time function after an electric vehicle stops.SOLUTION: When the electric vehicle stops, the destination determination unit 14 determines a destination of the electric vehicle at the time of next traveling. The required electric power calculation unit 18 calculates the amount of electric power required for the electric vehicle to reach the destination during the next travel. The power consumption reduction processing part 20 executes processing for reducing power consumption by the on-vehicle system when the storage residual quantity of the on-vehicle battery is reduced to a threshold based on the required electric energy by continuously executing the stop time function by at least one on-vehicle system after the electric vehicle is stopped.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a vehicle energy management device provided in an electric vehicle that runs using power stored in an on-board battery. [Background technology]

[0002] Patent Document 1 describes a vehicle system capable of reducing power consumption in a vehicle. The vehicle system in Patent Document 1 acquires information about the remaining battery charge of the vehicle, and, based on the acquired remaining battery charge, determines an execution mode for each of a plurality of functions executed by one or more functional modules of the vehicle after the vehicle's driving system is stopped.

[0003] For example, in Patent Document 1, one or more functional modules execute functions such as emergency call, security, and remote control after the vehicle's driving system is stopped. The vehicle system assigns the "normal" mode to each functional module when the vehicle's remaining battery charge is equal to or greater than a predetermined value (e.g., 20%). On the other hand, when the vehicle's remaining battery charge falls below the predetermined value, the vehicle system assigns the "normal" mode only to the functional module that executes emergency call processing, and assigns the "pause" mode to the functional modules that execute security processing and remote control processing. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2023-45312 Summary of the Invention [Problem to be solved by the invention]

[0005] In recent years, the number of electric vehicles that run using power stored in an onboard battery has been increasing. In such electric vehicles, it is necessary to prevent the onboard battery from running out of power (so-called running out of power) while the vehicle is on its way to its destination. However, as described in Patent Document 1, simply determining the execution mode of the process (stop function) that one or more functional modules execute after the vehicle's driving system is stopped, taking into account the remaining battery charge of the vehicle, is not sufficient to prevent running out of power.

[0006] The present disclosure has been made in consideration of the above-mentioned points, and aims to provide a vehicle energy management device that can more reliably prevent power shortage even when at least one on-board system continues to perform a stop-time function after the electric vehicle has stopped. [Means for solving the problem]

[0007] In order to achieve the above object, a vehicle energy management device according to the present disclosure is a vehicle energy management device provided in an electric vehicle that runs using power stored in an on-board battery, a remaining charge information acquisition unit (12) that acquires information about the remaining charge of an in-vehicle battery; a destination determination unit (14) that determines a destination of the electric vehicle for the next travel when the electric vehicle stops; a required energy calculation unit (18) that calculates the amount of energy required for the electric vehicle to reach the destination the next time it travels; and a power consumption reduction processing unit (20) that executes processing to reduce power consumption by the on-board system when the remaining charge of the on-board battery drops to a threshold based on the required power amount due to at least one on-board system continuously executing a stop function after the electric vehicle has stopped.

[0008] In this way, in the vehicle energy management device according to the present disclosure, when the electric vehicle stops, the destination determination unit determines the destination of the electric vehicle for the next time it travels. The required energy calculation unit calculates the amount of energy required for the electric vehicle to reach the destination the next time it travels. Then, when at least one on-board system continues to execute a stop function after the electric vehicle stops, and the remaining charge of the on-board battery drops to a threshold based on the required energy, the power consumption reduction processing unit executes processing to reduce power consumption by the on-board system.

[0009] Therefore, even if at least one on-board system continues to execute a stop function after the electric vehicle has stopped, it becomes easier to secure the amount of power required for the electric vehicle to reach its destination the next time it travels. As a result, it becomes possible to more reliably prevent the electric vehicle from running out of power while it is on its way to its destination.

[0010] The reference numbers in parentheses above merely indicate an example of a correspondence with specific configurations in the embodiments described below, in order to facilitate understanding of the present disclosure, and are not intended to limit the scope of the present disclosure in any way.

[0011] Furthermore, the technical features of the present disclosure other than those described above will become apparent from the following description of the embodiments and the accompanying drawings. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a configuration diagram illustrating an example of a configuration of a vehicle energy management device according to an embodiment; [Figure 2] 5 is a flowchart showing an example of a process executed in the energy management ECU according to the embodiment for managing the remaining amount of stored power in the main battery when the electric vehicle is stopped. [Figure 3] 10 is a time chart showing an example of changes in the remaining amount of power stored in the main battery, the amount of power required to reach the destination, and the power reduction threshold while the electric vehicle is parked. [Figure 4] 10 is a time chart showing an example of changes in the remaining charge amount of the main battery, the battery temperature, and the travel distance from when the electric vehicle starts traveling toward the destination until it arrives at the destination. [Figure 5] 10 is a flowchart showing an example of a process executed in an energy management ECU according to a modified example for managing the remaining amount of stored power in the main battery when the electric vehicle is stopped. [Figure 6] FIG. 10 is a diagram showing an example of a modified example in which the predetermined time corresponding to the interval at which the processing shown in the flowchart of FIG. 2 is executed is changed depending on the amount of power consumption per unit time caused by the in-vehicle system continuously executing functions during stoppage. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, embodiments of a vehicle energy management device according to the present disclosure will be described with reference to the drawings. However, the present disclosure is not limited to the following embodiments, and various modifications described below are also included within the technical scope of the present disclosure. Furthermore, in addition to the following, various modifications can be implemented without departing from the spirit of the present disclosure. The embodiments and various modifications can be implemented in appropriate combinations as long as no technical contradiction occurs. In the following description, identical or similar components may be assigned the same reference numerals across multiple drawings, and their description may be omitted. Furthermore, when only a portion of a component is mentioned, the description provided elsewhere may apply to the other components.

[0014] (First embodiment) FIG. 1 is a configuration diagram showing an example of the configuration of a vehicle energy management device according to this embodiment. In FIG. 1, an energy management ECU 10 corresponds to the vehicle energy management device. The energy management ECU 10 according to this embodiment is mounted on an electric vehicle that runs using power stored in an on-board battery (not shown). Note that electric vehicles include electric automobiles that use a motor as a driving source, as well as industrial vehicles and construction vehicles.

[0015] An electric vehicle is equipped with two onboard batteries: a main battery that supplies a high voltage for driving the motor, and an auxiliary battery that supplies a low voltage for operating various onboard systems (such as a first onboard system 30, a second onboard system 32, and a third onboard system 34) mounted on the vehicle. Note that some onboard systems can also operate using the high voltage supplied from the main battery. For example, an air conditioning system may use the high voltage supplied from the main battery to operate a compressor.

[0016] The main battery is, for example, a lithium-ion battery or a nickel-metal hydride battery, and is capable of supplying a high voltage of several hundred volts (e.g., 400 V) of direct current. The main battery is configured to be able to be charged at a charging spot equipped with charging equipment. The main battery is also configured to be able to be charged using power regenerated by the motor. The auxiliary battery is a normal lead battery, and is capable of supplying a low voltage of 12 volts or 24 volts of direct current. When the amount of stored power in the auxiliary battery decreases due to the operation of various on-board systems, the auxiliary battery is configured to be charged by the main battery via a DC-DC converter.

[0017] Among the various in-vehicle systems, the first to third in-vehicle systems 30 to 34 operate when the electric vehicle is stopped. For example, the first in-vehicle system 30 has a stop-time function that makes an emergency call to an operator outside the vehicle when an abnormality occurs, such as an abnormality occurring to the vehicle user or an accident or breakdown occurring in the electric vehicle. The first in-vehicle system 30 also enables the emergency call function when the vehicle is moving. For example, when a predetermined trigger occurs, such as detection of an abnormality occurring to the driver, pressing of a call button provided in the vehicle, or deployment of an airbag, the first in-vehicle system 30 makes an emergency call to an operator, enabling a conversation between the vehicle occupant and the operator. The first in-vehicle system 30 may also transmit vehicle location information detected by GPS to the operator when making an emergency call.

[0018] The second in-vehicle system 32 performs security monitoring as a function during vehicle shutdown. For example, if the electric vehicle is unlocked without following the correct procedure, the second in-vehicle system 32 sends a security notification to an external management server. Furthermore, if the second in-vehicle system 32 detects that the vehicle body has been subjected to an impact, vibration, or the like, it sends a security notification to the external management server.

[0019] In response to a security report from the electric vehicle, the management server may transmit a security notification to the user's mobile device or the like, indicating that the lock has been released or that the vehicle has been subjected to an impact, vibration, or the like. The security report to the external management server may also include vehicle location information. When it is determined that a security problem has occurred in the electric vehicle, the second in-vehicle system 32 may periodically transmit the location information of the electric vehicle to the external server. The security report to the external management server may also include images of the area around the vehicle or the interior of the vehicle.

[0020] As a stop function, the third in-vehicle system 34 controls the operation of various in-vehicle systems of the electric vehicle based on various request signals transmitted from outside the electric vehicle. For example, the third in-vehicle system 34 starts the operation of the air conditioning system before the user gets into the electric vehicle in response to a request to start the air conditioning system. In addition, the third in-vehicle system 34 may be capable of starting the operation of, for example, a seat heater, a steering heater, a defroster, etc. based on the request signal.

[0021] The above-described first to third in-vehicle systems 30 to 34 are examples of in-vehicle systems that execute stop-time functions. The in-vehicle system that executes the stop-time function may be at least one of the first to third in-vehicle systems 30 to 34. Conversely, the in-vehicle system that executes the stop-time function may execute another stop-time function in addition to or instead of the first to third in-vehicle systems 30 to 34.

[0022] The energy management ECU 10 is for managing the state of charge (SOC) of the main battery when the electric vehicle is stopped. In particular, the energy management ECU 10 in this embodiment manages the state of charge of the main battery so that the amount of power required for the electric vehicle to reach its destination the next time it travels can be easily secured, even when at least one of the in-vehicle systems including the first to third in-vehicle systems 30 to 34 continues to execute a stop-time function. This makes it possible to prevent the electric vehicle from running out of power while it is on its way to its destination the next time it travels. The energy management ECU 10 according to this embodiment will be described in detail below.

[0023] The energy management ECU 10 may be configured by a computer. The computer may have at least one memory and one processor. The memory may be at least one type of non-transitory tangible storage medium, such as a semiconductor memory, a magnetic medium, or an optical medium, that non-temporarily stores programs and data readable by the processor. Furthermore, the memory may be a rewritable volatile storage medium, such as a random access memory (RAM). The processor may include at least one type of processor core, such as a central processing unit (CPU), a graphics processing unit (GPU), or a reduced instruction set computer (RISC). The computer may also be a system on a chip (SoC), which integrates the memory, processor, and external interfaces on a single chip. Alternatively, the energy management ECU 10 may be configured by a hardware circuit, such as an application specific integrated circuit (ASIC) or a field programmable gate array (FPGA).

[0024] 1 is a block diagram showing functional units of the energy management ECU 10. These functional units can be realized, for example, by at least one processor executing a program stored in a memory. As shown in FIG. 1, the energy management ECU 10 has, as its functional units, a remaining battery charge information acquisition unit 12, a destination determination unit 14, a schedule information acquisition unit 16, a required energy calculation unit 18, and a power consumption reduction processing unit 20.

[0025] The remaining battery charge information acquisition unit 12 acquires information about the remaining battery charge (SOC) of the main battery mounted on the electric vehicle. For example, the remaining battery charge information acquisition unit 12 can acquire information about the SOC, which corresponds to the remaining battery charge, from the voltage of the main battery in an open state according to an SOC-OCV curve. Alternatively, the remaining battery charge information acquisition unit 12 can acquire information about the SOC using a Kalman filter or machine learning.

[0026] The destination determination unit 14 determines the destination of the electric vehicle for the next trip in response to the electric vehicle stopping. The stopping of the electric vehicle can be detected, for example, by the shift position being switched to park, the main switch of the electric vehicle being turned off, or the user getting off the electric vehicle and locking the doors. Then, the destination determination unit 14 can determine, for example, the charging spot that is closest to the current location of the electric vehicle and has charging equipment capable of charging the main battery, as the destination for the next trip. Alternatively, the destination determination unit 14 may notify the user, via a navigation device or the user's mobile device, of charging spots that can be reached with the current remaining charge level of the main battery, and determine the charging spot selected by the user as the destination for the next trip.

[0027] The schedule information acquisition unit 16 acquires schedule information related to the scheduled date and time when the next trip will start. For example, the schedule information acquisition unit 16 may acquire the schedule information by inquiring about the scheduled date and time when the next trip will start and the parking period through an in-vehicle audio system or the user's mobile terminal and obtaining a response from the user. Alternatively, the schedule information acquisition unit 16 may read the user's schedule from the user's mobile terminal or the like and acquire the schedule information from the read schedule.

[0028] The required energy calculation unit 18 calculates the amount of energy required for the electric vehicle to reach the destination determined by the destination determination unit 14 the next time it travels. Specifically, the required energy calculation unit 18 calculates the amount of energy required to reach the destination based on the distance between the current position of the electric vehicle and the destination determined by the destination determination unit 14, taking into account the electricity consumption of the electric vehicle. In addition, the required energy calculation unit 18 may calculate the amount of energy required to reach the target value by taking into account various information. Below, some specific examples of information that the required energy calculation unit 18 can take into account will be described.

[0029] The required power calculation unit 18 may calculate the required power taking into account the running resistance based on the tire pressure of the electric vehicle. If the detected tire pressure is lower than the standard tire pressure, the running resistance of the electric vehicle increases. Conversely, if the detected tire pressure is higher than the standard tire pressure, the running resistance of the electric vehicle decreases. The required power calculation unit 18 can calculate the required power taking into account the running resistance, for example, by correcting the electric fuel efficiency of the electric vehicle in accordance with an increase or decrease in the running resistance of the electric vehicle.

[0030] The required energy calculation unit 18 may calculate the required energy amount taking into account the deterioration state of the main battery. Here, SOC is an index that indicates the charging rate of the main battery relative to its full charge level. Therefore, when the required energy amount is indicated by the SOC, as the main battery deteriorates and its full charge level decreases, the energy amount indicated by the SOC also decreases. Therefore, the required energy calculation unit 18 can improve the accuracy of calculating the required energy amount by increasing the SOC according to the deterioration state of the main battery. The deterioration state of the main battery can be determined, for example, from the calculated value of the SOH (State Of Charge), the cumulative number of charge / discharge cycles of the main battery, the duration of continuous use of the main battery, etc.

[0031] The required power calculation unit 18 may acquire at least one piece of predicted information of environmental information and traffic information for the scheduled date and time of the next trip (also referred to as the start time of the next trip) based on the schedule information acquired by the schedule information acquisition unit 16, and calculate the required power amount based on the acquired predicted information. The environmental information includes information on weather, outside temperature, humidity, amount of solar radiation, amount of precipitation, wind speed, wind direction, etc. The traffic information includes information on traffic congestion, road closures, etc.

[0032] For example, if the outside air temperature at the scheduled date and time of the next trip is below a predetermined temperature (e.g., 0 degrees), there is a high possibility that the battery temperature regulation system will heat the main battery to prevent a decrease in the charge / discharge capacity of the main battery. Therefore, the required power calculation unit 18 acquires predicted information of environmental information including the outside air temperature, and if the outside air temperature included in the predicted information is below a predetermined temperature (e.g., 0 degrees), calculates the energy required to heat the main battery to the predetermined temperature. The required power calculation unit 18 may then calculate the amount of power required to generate the calculated energy, and add the calculated amount of power to calculate the required power.

[0033] Furthermore, if the outside air temperature at the scheduled date and time of the next trip is low (e.g., 10 degrees or lower) or high (e.g., 25 degrees or higher), there is a high possibility that the driver of the electric vehicle will use the air conditioning system while the electric vehicle is traveling toward the destination. Therefore, the required power calculation unit 18 may acquire predicted information of environmental information including the outside air temperature and determine the possibility of using the air conditioning system based on the outside air temperature included in the predicted information. Then, if it determines that there is a high possibility that the air conditioning system will be used, the required power calculation unit 18 may calculate the energy required to use the air conditioning system based on the predicted information of environmental information (particularly the outside air temperature). Then, the required power calculation unit 18 may calculate the amount of power required to generate the calculated energy and add the calculated amount of power to calculate the required power.

[0034] To determine the possibility of using the air conditioning system, the required energy calculation unit 18 may inquire of the user of the electric vehicle whether or not to use the air conditioning system when traveling to the destination. When the required energy calculation unit 18 receives a response from the user indicating that the air conditioning system will be used, it acquires predicted information on environmental information and calculates the energy required to use the air conditioning system based on the acquired predicted information on environmental information. The required energy calculation unit 18 may then calculate the amount of power required to generate the calculated energy and add the calculated amount of power to calculate the required energy.

[0035] Alternatively, the required energy calculation unit 18 may calculate the energy required to operate the air conditioning system based on the weather, humidity, amount of solar radiation, and the like in addition to the outside air temperature. Furthermore, the required energy calculation unit 18 may determine the possibility of using the wiper system based on the amount of precipitation, and if it determines that the wiper system is likely to be used, calculate the energy required to operate the wiper system. The required energy calculation unit 18 may then calculate the amount of power required to generate the calculated energy and add the calculated amount of power to calculate the required amount of power. Furthermore, the required energy calculation unit 18 may determine an increase or decrease in the running resistance of the electric vehicle based on wind speed and wind direction, and calculate the required amount of power taking into account the result of the determination of the increase or decrease in running resistance.

[0036] Furthermore, with regard to the predicted traffic information, the required energy calculation unit 18 repeatedly calculates the driving route to the destination based on the traffic information for the scheduled date and time of the next driving. In calculating this driving route, if congestion or a road closure due to construction is predicted on the original driving route assumed at the time of stopping, the required energy calculation unit 18 calculates a driving route that avoids the congestion or road closure. In this way, when the driving route to the destination changes, the required energy calculation unit 18 changes the calculated required energy to the amount of energy required to drive the changed driving route.

[0037] It is desirable that the required energy calculation unit 18 periodically and repeatedly calculates the amount of required energy based on prediction information of at least one of environmental information and traffic information from the time the electric vehicle is stopped until the next time it starts traveling, thereby updating the calculated amount of required energy to the amount of required energy based on the latest prediction information. The prediction information of environmental information and traffic information may change. By periodically and repeatedly calculating the amount of required energy based on the prediction information, the required energy calculation unit 18 can calculate the amount of required energy required to reach the destination based on the latest prediction information.

[0038] Preferably, the power consumption reduction processing unit 20 sets the power reduction threshold by adding a predetermined margin to the required amount of power calculated by the required amount of power calculation unit 18. Then, when the remaining charge of the main battery drops to the power reduction threshold due to at least one on-board system continuously executing a stop function after the electric vehicle has stopped, the power consumption reduction processing unit 20 executes processing to reduce the power consumption of at least one on-board system. This makes it easier to ensure the amount of power required for the electric vehicle to reach its destination the next time it travels, even if at least one on-board system continuously executes a stop function after the electric vehicle has stopped. As a result, it becomes possible to more reliably prevent the electric vehicle from running out of power while on its way to its destination.

[0039] As a process for reducing the power consumption of at least one in-vehicle system, the power consumption reduction processing unit 20 may, for example, stop a stop function of at least one in-vehicle system. Alternatively, the power consumption reduction processing unit 20 may lengthen the execution interval of the stop function of at least one in-vehicle system. Furthermore, when there are multiple in-vehicle systems that execute stop functions, the power consumption reduction processing unit 20 may stop the stop functions of some or all of the multiple in-vehicle systems, or may lengthen the execution interval of the stop functions of some or all of the multiple in-vehicle systems.

[0040] The power consumption reduction processing unit 20 may determine the predetermined margin to be added to the required power amount by taking into account the power consumption of at least one in-vehicle system after the power consumption reduction processing for that at least one in-vehicle system has been executed. For example, if the power consumption reduction processing unit 20 lengthens the execution interval of the stop-time functions of at least one in-vehicle system or disables only some of the stop-time functions of multiple in-vehicle systems that execute the stop-time functions as a power consumption reduction processing, the stop-time functions of the in-vehicle systems are executed with reduced power consumption even after the remaining charge of the main battery has fallen to the power reduction threshold. For this reason, it is preferable that the power consumption reduction processing unit 20 set the predetermined margin so that the required power amount remains in the main battery after the power consumption reduction processing is completed and the power consumption by the stop-time functions of the in-vehicle systems is covered.

[0041] For example, the power consumption reduction processing unit 20 can set a predetermined margin based on the stop period of the electric vehicle, the remaining power of the main battery when the electric vehicle is stopped, the amount of power consumed by the on-board system before the power consumption reduction processing, and the amount of power consumed by the on-board system before the power consumption reduction processing so that at least the required amount of power remains in the main battery at the end of the stop period of the electric vehicle.In this case, if natural discharge occurs in the main battery, it is preferable that the power consumption reduction processing unit 20 sets the predetermined margin taking into account the natural discharge of the main battery in the period until the start of the next driving.

[0042] Next, an example of processing executed by the energy management ECU 10 to manage the state of charge (SOC) of the main battery when the electric vehicle is stopped will be described with reference to the flowchart of FIG.

[0043] In step S100, the energy management ECU 10 determines whether the electric vehicle has stopped. If it is determined that the electric vehicle has stopped, the energy management ECU 10 proceeds to the process of step S110. On the other hand, if it is determined that the electric vehicle has not stopped, the energy management ECU 10 ends the process shown in the flowchart of FIG. 2.

[0044] In step S110, the energy management ECU 10 determines the destination of the electric vehicle for the next trip. As described above, the destination of the electric vehicle is preferably determined to be a charging spot equipped with charging equipment capable of charging the main battery. In step S120, the energy management ECU 10 acquires schedule information related to the scheduled date and time when the electric vehicle will start its next trip.

[0045] In step S130, the energy management ECU 10 acquires, as disturbance information for the next driving of the electric vehicle, prediction information of at least one of the environmental information and traffic information described above, information about tire pressure, and information about the deterioration state of the main battery.

[0046] In step S140, the energy management ECU 10 calculates the amount of power required for the electric vehicle to reach the determined destination the next time it travels. At this time, the energy management ECU 10 calculates the amount of power required to reach the destination based on the distance between the current position of the electric vehicle and the determined destination, taking into account the electricity consumption of the electric vehicle. In addition, it is preferable that the energy management ECU 10 calculates the final amount of power required taking into account various information acquired as disturbance information.

[0047] In step S150, the energy management ECU 10 sets a power reduction threshold by adding a predetermined margin to the required power amount calculated in step S140. As described above, the predetermined margin is preferably determined taking into consideration the power consumption by the on-board system after the power consumption reduction process is executed and the natural discharge of the main battery during the period until the electric vehicle starts its next run.

[0048] In step S160, the energy management ECU 10 detects the current remaining charge of the main battery. Then, in step S170, the energy management ECU 10 determines whether the current remaining charge of the main battery has fallen below the power reduction threshold set in step S150. If it is determined that the current remaining charge of the main battery has fallen below the power reduction threshold, the energy management ECU 10 proceeds to the process of step S240. On the other hand, if it is determined that the current remaining charge of the main battery has not fallen below the power reduction threshold, the energy management ECU 10 proceeds to the process of step S180.

[0049] In step S180, the energy management ECU 10 instructs at least one in-vehicle system that executes a stop-time function to execute the stop-time function in normal mode. That is, the energy management ECU 10 instructs at least one in-vehicle system to execute the stop-time function in its original execution cycle. As a result, at least one in-vehicle system starts executing the stop-time function in normal mode. Then, in step S190, the energy management ECU 10 waits for a predetermined time (for example, one hour). During this wait, the energy management ECU 10 enters sleep mode. As a result, the process shown in the flowchart in FIG. 2 is executed at predetermined time intervals. This makes it possible to reduce power consumption by the energy management ECU 10 in the atmosphere for a predetermined time.

[0050] In step S200, the energy management ECU 10 checks whether the destination for the next trip of the electric vehicle has been changed and the destination has been updated. The user of the electric vehicle can change the destination at any time via the in-vehicle navigation device or the user's mobile terminal. In addition, in step S210, the energy management ECU 10 checks whether the start time of the next trip of the electric vehicle has been changed and the next trip start time has been updated. The user of the electric vehicle can change the next trip start time at any time via the in-vehicle navigation device or the user's mobile terminal. In addition, in step S220, the energy management ECU 10 checks whether the disturbance information has been updated.

[0051] In step S230, the energy management ECU 10 determines whether at least one of the destination, the travel start time, and the disturbance information has been updated based on the check results in steps S200, S210, and S220. If it is determined that at least one of the destination, the travel start time, and the disturbance information has been updated, the energy management ECU 10 proceeds to the process of step S140. In this case, in step S140, the energy management ECU 10 recalculates the amount of power required to reach the destination based on the latest destination, the latest travel start time, and the latest disturbance information. Furthermore, in step S150, the energy management ECU 10 resets the power reduction threshold based on the recalculated amount of power required. On the other hand, if it is determined that none of the destination, the travel start time, and the disturbance information has been updated, the energy management ECU 10 proceeds to the process of step S160.

[0052] In step S240, because the remaining charge of the main battery has fallen below the power reduction threshold, the energy management ECU 10 instructs at least one in-vehicle system that executes a stop function to stop the execution of the stop function or to lengthen the cycle of executing the stop function. In response to this instruction, the at least one in-vehicle system switches the execution mode of the stop function from the normal mode to the off mode or the power saving mode. Then, in step S250, the energy management ECU 10 notifies the user that the at least one in-vehicle system has switched the execution mode of the stop function to the off mode or the power saving mode, and ends the processing shown in the flowchart of FIG. 2.

[0053] Next, an example of management of the remaining charge of the main battery by the process shown in the flowchart of Fig. 2 will be described with reference to the time charts of Fig. 3 and Fig. 4. The time chart of Fig. 3 shows an example of changes in the remaining charge of the main battery, the amount of power required to reach the destination, and the power reduction threshold while the electric vehicle is parked. The time chart of Fig. 4 shows an example of changes in the remaining charge of the main battery, the battery temperature, and the traveling distance from when the electric vehicle starts traveling toward the destination until it reaches the destination.

[0054] The time chart in Figure 3 shows an example in which an electric vehicle is parked for 14 days, for example, in an airport parking lot. While the vehicle is parked, at least one on-board system executes a parked function. As a result, the state of charge (SOC) of the main battery decreases over time. When the vehicle is parked, the destination and the start time of the next trip (or parking period) are determined. Based on the determined destination, parking period, and disturbance information, the amount of power required to reach the destination and the power reduction threshold are set.

[0055] As described above, the process shown in the flowchart of Fig. 2 is repeatedly executed at predetermined time intervals. For example, assume that the outside air temperature at the start of driving is predicted to be -5°C based on the prediction information related to the outside air temperature in the disturbance information when the electric vehicle is parked. However, assume that the outside air temperature at the start of driving changes to -15°C based on the disturbance information acquired on the 11th day after parking in the process repeated at predetermined time intervals. In this case, since the temperature of the main battery is affected by the outside air temperature, it is predicted that the temperature of the main battery at the start of the next driving will also drop to -15°C.

[0056] When the temperature of the main battery drops to -15°C, the charging and discharging capability of the main battery decreases, making it difficult to extract the desired amount of power from the main battery. Therefore, the main battery needs to be warmed to, for example, approximately 0°C by the battery temperature control system. For this reason, in the example shown in FIG. 3, on the 11th day after the vehicle began parking, the required amount of power is increased to ensure that the battery temperature control system has enough energy to warm the main battery. As a result, the power reduction threshold is also increased.

[0057] In the example shown in Figure 3, the remaining charge of the main battery falls below the power reduction threshold on the 12th day after the vehicle starts parking. Therefore, the energy management ECU 10 instructs the in-vehicle system to stop executing the stop function. As a result, further decrease in the remaining charge of the main battery is suppressed.

[0058] When the 14-day parking period ends and the electric vehicle starts to move, the main battery will have enough power remaining to heat the main battery to 0°C using the battery temperature control system, as well as enough power for the electric vehicle to reach its destination. Therefore, as shown in the example in Figure 4, in the electric vehicle, the battery temperature control system first heats the main battery to 0°C, and then the electric vehicle can safely drive to its destination 10 km away.

[0059] Note that Figures 3 and 4 explain the case where the outside air temperature at the start of the next journey has changed, but if any change occurs, such as if the destination is changed, if the start of the next journey is changed, or if external disturbance information including the outside air temperature is changed, the required power amount and power reduction threshold can be similarly updated based on the latest information when the change is confirmed.

[0060] As described above, the energy management ECU 10 according to this embodiment executes processing to reduce power consumption by at least one on-board system when the remaining charge of the main battery drops to the power reduction threshold due to at least one on-board system continuously executing a stop function after the electric vehicle has stopped. This makes it easier to ensure the amount of power required for the electric vehicle to reach its destination the next time it travels, even when at least one on-board system continuously executes a stop function after the electric vehicle has stopped. As a result, it becomes possible to more reliably prevent the electric vehicle from running out of power while it is on its way to its destination.

[0061] (Variation) The above-described embodiments are preferred embodiments of the present disclosure, but the present disclosure is not limited to the above-described embodiments and can be implemented in various modified forms within the scope that does not deviate from the gist of the present disclosure.

[0062] For example, in the above-described embodiment, in response to determining that the remaining charge of the main battery has fallen below the power reduction threshold, the energy management ECU 10 instructs the in-vehicle system that executes the stop-time function to switch the stop-time function to off mode or power-saving mode.

[0063] 5, in response to determining in step S170 that the remaining charge level of the main battery has fallen below the power reduction threshold, the energy management ECU 10 may notify the user in step S260 that the in-vehicle system's stop-time functions are recommended to be switched from the normal mode to the off mode or the power-saving mode. In this case, in step S270, the energy management ECU 10 determines whether a request to switch to the off mode or the power-saving mode has been received from the user. If it is determined that a switching request has been received, the energy management ECU 10 proceeds to processing in step S280, where the energy management ECU 10 instructs the in-vehicle system to switch the execution mode of the stop-time functions, thereby performing the switching, and notifies the user that the switching has been completed.

[0064] In the above-described embodiment, an example has been described in which the energy management ECU 10 executes the process shown in the flowchart of FIG. 2 at predetermined time intervals, regardless of the power consumption per unit time caused by the on-board system continuously executing parked functions while the electric vehicle is parked.

[0065] However, the energy management ECU 10 may change the predetermined time, which corresponds to the interval at which the process shown in the flowchart of Fig. 2 is performed, depending on the amount of power consumed per unit time by the in-vehicle system continuously executing functions while the vehicle is stopped. For example, as shown in the graph of Fig. 6, the energy management ECU 10 may shorten the predetermined time, which is the interval at which the required amount of power is calculated periodically, the greater the power consumed per unit time by the in-vehicle system continuously executing functions while the vehicle is stopped. [Explanation of symbols]

[0066] 10: Energy management ECU, 12: Remaining power storage information acquisition unit, 14: Destination determination unit, 16: Schedule information acquisition unit, 18: Required power amount calculation unit, 20: Power consumption reduction processing unit, 30: First vehicle system, 32: Second vehicle system, 34: Third vehicle system

Claims

1. A vehicle energy management device provided in an electric vehicle that runs using power stored in an on-board battery, a remaining charge information acquisition unit (12) for acquiring information about the remaining charge of the in-vehicle battery; a destination determination unit (14) that determines a destination of the electric vehicle for the next travel when the electric vehicle stops; a required energy calculation unit (18) that calculates the amount of energy required for the electric vehicle to reach the destination the next time it travels; and a power consumption reduction processing unit (20) that executes processing to reduce power consumption by the on-board system when the remaining charge of the on-board battery drops to a threshold based on the required amount of power as a result of at least one on-board system continuously executing a stop-time function after the electric vehicle has stopped.

2. 2. The vehicle energy management device according to claim 1, wherein the destination determination unit determines, as the destination of the electric vehicle, a charging spot that is closest to a current location of the electric vehicle and has charging equipment capable of charging the on-board battery.

3. 2. The vehicle energy management device according to claim 1, wherein the destination determination unit notifies a user of the electric vehicle of charging spots that are reachable with a current remaining amount of power stored in the on-board battery and that have charging equipment that can charge the on-board battery, and determines the charging spot selected by the user of the electric vehicle as the destination of the electric vehicle.

4. The vehicle further includes a schedule information acquisition unit (16) that acquires schedule information regarding the scheduled date and time when the next trip is to start, 2. The vehicle energy management device according to claim 1, wherein the required energy calculation unit acquires prediction information of at least one of environmental information and traffic information for the scheduled date and time, and calculates the required energy based on the acquired prediction information.

5. 5. The vehicle energy management device according to claim 4, wherein the required power calculation unit acquires predicted information of the environmental information including an outside air temperature, and when the outside air temperature is equal to or lower than a predetermined temperature, calculates the required power amount taking into account energy required to warm the on-board battery.

6. 5. The vehicle energy management device according to claim 4, wherein the required energy calculation unit queries a user of the electric vehicle about whether or not to use an air conditioning system of the electric vehicle when traveling to the destination, and when receiving a response that the air conditioning system will be used, acquires predicted information of the environmental information, and calculates the required energy in consideration of energy required to use the air conditioning system, which is calculated based on the acquired predicted information of the environmental information.

7. 5. The vehicle energy management device according to claim 4, wherein the required energy calculation unit acquires predicted information about the traffic information, calculates a driving route to the destination based on the acquired predicted information about the traffic information, and, if the calculated driving route changes from the driving route assumed when the electric vehicle was stopped, changes the required energy to an amount of energy that is required for driving the changed driving route.

8. 8. The vehicle energy management device according to claim 4, wherein the required energy calculation unit periodically calculates the required energy based on prediction information of at least one of the environmental information and the traffic information, thereby updating the required energy to the required energy based on latest prediction information.

9. 9. The vehicle energy management device according to claim 8, wherein the required power calculation unit periodically calculates the required power amount at shorter intervals as the power consumption per unit time due to the in-vehicle system continuously executing the stop-time function increases.

10. The vehicle energy management device according to claim 1 , wherein the required power amount calculation unit calculates the required power amount in consideration of a running resistance based on tire air pressure of the electric vehicle.

11. The vehicle energy management device according to claim 1 , wherein the required power amount calculation unit calculates the required power amount in consideration of a deterioration state of the vehicle battery.

12. The vehicle energy management device according to claim 1 , wherein the power consumption reduction processing unit sets the threshold value so as to have a predetermined margin with respect to the required amount of power.

13. The vehicle further includes a schedule information acquisition unit (16) that acquires schedule information regarding the scheduled date and time when the next trip is to start, The vehicle energy management device according to claim 12, wherein the power consumption reduction processing unit determines the predetermined margin in consideration of natural discharge of the in-vehicle battery during a period until the start of the next driving.

14. The vehicle energy management device according to claim 12 , wherein the power consumption reduction processing unit determines the predetermined margin in consideration of the power consumption by the in-vehicle system after reduction by the power consumption reduction processing unit.

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