JP7643374B2 - Battery Temperature Control Device - Google Patents

Description

The present invention relates to a battery temperature control device.

Conventionally, when a vehicle is predicted to pass through a specific area (road pricing area) and it is predicted that the amount of energy required to pass through the specific area is insufficient, it is known to set the minimum charge level required to pass through the specific area using EV driving as the target charge level during external charging, or to provide guidance to urge the occupants to charge (for example, Patent Document 1).

JP 2009-241804 A

The technology described in Patent Document 1 aims to alleviate the energy shortage by charging when the amount of energy required to pass through a specific area is insufficient.

However, when driving a vehicle using only the driving force of the motor in certain areas where the use of the engine is restricted, if the battery temperature drops or if the battery overheats, the battery output drops and the vehicle's driving force may be insufficient. The technology described in Patent Document 1 does not take into account the drop in driving force caused by the battery temperature, so there is a problem of insufficient driving force when the vehicle travels in certain areas.

In view of the above problems, the objective of the present disclosure is to provide a battery temperature control device that can suppress a decrease in the driving force of a vehicle caused by a motor when the vehicle is traveling in a specific area where the use of the engine is restricted.

The gist of this disclosure is as follows:

1. A device for controlling a temperature of a battery in a vehicle including an engine, a battery, and a motor that receives power from the battery to drive the vehicle, comprising:
a temperature range acquisition unit that acquires a temperature range of the battery within which the battery can output a predetermined output for driving the vehicle using only the driving force of the motor;
a temperature control unit that controls a temperature of the battery so that the temperature of the battery is within the temperature range before the vehicle reaches a specific area where the use of the engine is restricted;
A battery temperature control device comprising:

According to the present disclosure, a battery temperature control device is provided that can suppress a decrease in the driving force of a vehicle by the motor when the vehicle is traveling in a specific area where the use of the engine is restricted.

1 is a schematic diagram showing a configuration of a vehicle control system according to an embodiment; 1 is a schematic diagram showing a configuration of a vehicle control system mounted on a vehicle. FIG. 2 is a schematic diagram showing the detailed configuration of a vehicle control device. 2 is a schematic diagram showing functional blocks of a processor of an ECU provided in a vehicle; FIG. 4 is a characteristic diagram showing the relationship between the temperature of a battery and the output of the battery. 5 is a characteristic diagram showing a map for calculating a correction coefficient for correcting the amount of heat generation or the amount of cooling by a correction unit. FIG. 4 is a flowchart showing a process performed by a processor of the ECU. FIG. 11 is a schematic diagram showing functional blocks of a processor of an ECU provided in a vehicle in a second embodiment. 11 is a characteristic diagram for explaining a process flow in which an estimation unit estimates a battery temperature Tbe based on a planned driving route. FIG. FIG. 11 is a schematic diagram for explaining a method for estimating the time when a vehicle will enter a specific area inside a boundary line. FIG. 11 is a schematic diagram for explaining a method for estimating the time when a vehicle will enter a specific area inside a boundary line. 5 is a characteristic diagram showing a map for calculating a correction coefficient for correcting the amount of heat generation or the amount of cooling by a correction unit. FIG. 4 is a flowchart showing a process performed by a processor of the ECU. FIG. 13 is a schematic diagram showing functional blocks of a processor of an ECU provided in a vehicle in a third embodiment. 4 is a flowchart showing a process performed by a processor of the ECU. FIG. 13 is a schematic diagram showing functional blocks of a processor of an ECU provided in a vehicle in a fourth embodiment. 4 is a flowchart showing a process performed by a processor of the ECU.

Several embodiments of the present invention will be described below with reference to the drawings. However, these descriptions are intended to merely exemplify preferred embodiments of the present invention, and are not intended to limit the present invention to such specific embodiments. In the following description, similar components will be given the same reference numbers.

First Embodiment
1 is a schematic diagram showing a configuration of a vehicle control system 1000 according to one embodiment. In this control system 1000, an area is defined by a virtual geographical boundary (hereinafter simply referred to as a boundary) 10, and a vehicle 100 performs different controls in a specific area inside the boundary 10 and an area outside the boundary 10. The vehicle 100 is a manually-driven vehicle that is manually driven by a driver, or an autonomously-driven vehicle capable of autonomous driving, and more specifically, a PHV (Plug-in Hybrid Vehicle).

The boundary line 10 separates, for example, an urban area from the surrounding area. In the urban area inside the boundary line 10, the density of vehicles 100 is high, and the population density is also high, so consideration must be given to people and the environment, such as by suppressing exhaust gas emitted from the vehicle 100. For this reason, use of the engine of the vehicle 100 is restricted in certain areas (urban areas) inside the boundary line 10. As an example, in this embodiment, in urban areas inside the boundary line 10, the engine of the vehicle 100 is required by law, government ordinance, etc. to be stopped. In urban areas inside the boundary line 10, the vehicle 100 stops its engine and runs in EV mode using the motor as a drive source.

On the other hand, in the area outside the boundary line 10, the density of vehicles 100 is low, and the population density is also low, so less consideration needs to be given to people and the environment compared to the urban area inside the boundary line 10. For this reason, in the area outside the boundary line 10, the vehicle 100 runs with the engine running, in a mode using both the engine and the motor as drive sources, or in a mode using only the engine as drive source.

As a result, exhaust gas emitted from engines is suppressed in the specific area inside the boundary line 10, so the air is kept clean even if there are many vehicles 100 in the specific area inside the boundary line 10.

However, when the vehicle 100 is traveling in EV mode using a motor as a drive source in a specific area inside the boundary line 10, if the battery of the vehicle 100 is cold or overheated, the battery output will decrease and driving force may be insufficient.

In this embodiment, a temperature range in which the battery 120d can output a target battery output is acquired. Then, before the vehicle 100 reaches a specific area inside the boundary line 10, the temperature of the battery 120d is controlled to be within the temperature range. This prevents a shortage of driving force when the vehicle 100 runs in an EV mode using the motor as a driving source in a specific area inside the boundary line 10, and ensures appropriate power performance of the vehicle 100.

FIG. 2 is a schematic diagram showing the configuration of a vehicle control system mounted on a vehicle 100. The vehicle control system includes a positioning information receiver 110, a vehicle control device 120, a wireless terminal 130, one or more sensors 140, a navigation device 150, an electronic control unit (ECU) 160, a heating/cooling device 170, and a display device 180. The positioning information receiver 110, the vehicle control device 120, the wireless terminal 130, one or more sensors 140, the navigation device 150, the ECU 160, the heating/cooling device 170, and the display device 180 are each connected to be able to communicate with each other via an in-vehicle network that complies with standards such as a Controller Area Network (CAN) and Ethernet (registered trademark).

The positioning information receiver 110 acquires positioning information that indicates the current position and attitude of the vehicle 100. For example, the positioning information receiver 110 may be a GPS (Global Positioning System) receiver. Each time the positioning information receiver 110 receives positioning information, it outputs the acquired positioning information to the ECU 160 via the in-vehicle network.

The vehicle control equipment 120 is various equipment related to vehicle control, and includes an engine 120a and motors 120b and 120c as driving sources for driving the vehicle 100, and a battery 120d for storing power.

The wireless terminal 130 is a communication interface with a communication network such as the Internet, and includes, for example, an antenna and a signal processing circuit that performs various processes related to wireless communication, such as modulating and demodulating wireless signals. For example, the wireless terminal 130 receives downlink wireless signals from a wireless base station connected to the communication network, and transmits uplink wireless signals to the wireless base station. From the received downlink wireless signals, the wireless terminal 130 extracts signals to be transmitted from an external server to the vehicle 100, and passes them to the ECU 160. The wireless terminal 130 also generates uplink wireless signals that include signals received from the ECU 160 and transmitted to the external server, and transmits the wireless signals.

The one or more sensors 140 include a sensor that detects the temperature of the battery 120d. The one or more sensors 140 also include a voltage sensor that detects the terminal current and terminal voltage of the battery 120d.

The navigation device 150 determines the planned route from the current location of the vehicle 100 to the destination according to a predetermined route search method such as the Dijkstra algorithm. For this reason, the navigation device 150 is provided with a memory that stores map information. The map information may be stored in the memory 164 of the ECU 160.

The ECU 160 has a processor 162, a memory 164, and a communication interface 166. The processor 162 has one or more CPUs (Central Processing Units) and their peripheral circuits. The processor 162 may further have other arithmetic circuits such as a logic arithmetic unit, a numerical arithmetic unit, or a graphic processing unit. The memory 164 has, for example, a volatile semiconductor memory and a non-volatile semiconductor memory. The memory 164 stores various information such as position information of the boundary line 10 and output characteristics of the battery 120d according to temperature. The communication interface 166 has an interface circuit for connecting the ECU 160 to an in-vehicle network.

The heating/cooling device 170 is a device that heats or cools the battery 120d, and is composed of, for example, a heater that heats the battery 120d, a fan that blows air onto the battery 120d to cool it, etc. Note that the battery 120d may be heated or cooled depending on the amount of heat it generates, in which case the vehicle control system does not need to be equipped with the heating/cooling device 170.

The display device 180 is, for example, a liquid crystal display (LCD) and is provided near the meter panel or dashboard to display various information.

Figure 3 is a schematic diagram showing the configuration of the vehicle control device 120. Specifically, the vehicle control device 120 includes an engine 120a, a power generation motor 120b, a drive motor 120c, a battery 120d, and inverters 120e and 120f. The power generation motor 120b rotates by the driving force of the engine 120a to generate electricity. The generated electricity is charged to the battery 120d via the inverter 120e. The output of the battery 120d is supplied to the drive motor 120c via the inverter 120f, and the wheels are driven by the driving force of the drive motor 120c. Note that the drive shafts of the engine 120a, the power generation motor 120b, and the drive motor 120c may be connected by planetary gears, and the wheels may be driven by the driving force of at least one of the engine 120a, the power generation motor 120b, and the drive motor 120c. In EV mode, the engine 120a is stopped and the wheels are driven only by the driving force of the motor.

Figure 4 is a schematic diagram showing the functional blocks of the processor 162 of the ECU 160 provided in the vehicle 100. The processor 162 has a vehicle information acquisition unit 162a, a temperature range acquisition unit 162b, a temperature control unit 162c, and a correction unit 162d. Each of these units of the processor 162 is a functional module realized by, for example, a computer program running on the processor 162. In other words, each of these units of the processor 162 is composed of the processor 162 and a program (software) for making it function. In addition, the program may be recorded in the memory 164 of the ECU 160 or a recording medium connected from the outside. Alternatively, each of these units of the processor 162 may be a dedicated arithmetic circuit provided in the processor 162.

The vehicle information acquisition unit 162a of the processor 162 acquires various information such as the current temperature Tb of the battery 120d, the current SOC of the battery 120d, and the distance from the current position of the vehicle 100 to the boundary line 10. The vehicle information acquisition unit 162a acquires the temperature Tb of the battery 120d detected by the sensor 140. The vehicle information acquisition unit 162a also acquires the current SOC from the terminal current and terminal voltage of the battery 120d detected by the sensor 140. The vehicle information acquisition unit 162a acquires the SOC, for example, by integrating the charge and discharge current of the battery 120d. The vehicle information acquisition unit 162a also acquires the distance from the current position of the vehicle 100 to the boundary line 10 based on the positioning information acquired by the positioning information receiver 110 and the position information of the boundary line 10 stored in the memory 164. The vehicle information acquisition unit 162a may acquire the distance from the current position of the vehicle 100 to the boundary line 10 based on information received by the wireless terminal 130 from an external server or the like.

The temperature range acquisition unit 162b of the processor 162 acquires the temperature range TbA-TbB of the battery 120d in which the battery 120d can output the target battery output for driving the vehicle 100 using only the driving force of the motors 120b and 120c. Figure 5 is a characteristic diagram showing the relationship between the temperature of the battery 120d and the output of the battery 120d, where the horizontal axis indicates the temperature of the battery 120d and the vertical axis indicates the output of the battery 120d.

Characteristic c1, shown by a solid line in Figure 5, indicates the output characteristic of battery 120d according to the temperature of battery 120d. As shown in characteristic c1, the output of battery 120d reaches a maximum value at a certain temperature, and decreases as the temperature drops below that temperature, and also decreases as the temperature rises above that temperature.

The target battery output shown in FIG. 5 is the output of battery 120d that is capable of driving vehicle 100 using only the outputs of motors 120b and 120c, and is a fixed value or a learned value. When the target battery output is a fixed value, the target battery output is determined based on the vehicle weight, the specifications of the drive motor, etc. Also, when the target battery output is a fixed value, the target battery output may be set to a value that allows the vehicle to travel in a driving pattern defined by, for example, WLTP (World Harmonized Light Duty Test Procedure).

When the target battery output is a learned value, the target battery output is learned, for example, from the output of battery 120d when vehicle 100 runs in a specific area inside boundary line 10 in EV mode. When the target battery output is a learned value, for example, the usual driving manner (driving characteristics) of each driver in EV mode is collected, and the frequency distribution showing the relationship between battery output and frequency represents a normal distribution, and an upper limit value in the range of ±2σ or ±3σ where σ is the standard deviation is learned as the target battery output. By learning the target battery output, heating control or cooling control, which will be described later, is not performed more than necessary, and energy efficiency such as power consumption is improved.

The temperature range acquisition unit 162b acquires the temperature range TbA-TbB of the battery 120d in which the battery 120d can output the target battery output based on the output characteristics (characteristic C1) of the battery 120d according to the temperature stored in the memory 164 and the target battery output, based on the characteristics shown in FIG. 5. Note that the temperature range TbA-TbB may be a predetermined fixed value, and may be stored in the memory 164 in advance, for example. In that case, the temperature range acquisition unit 162b acquires the temperature range TbA-TbB, which is a fixed value stored in the memory 164.

Characteristic C2 shown by a dashed line in FIG. 5 indicates the output characteristic of battery 120d when the SOC of battery 120d is higher than characteristic C1. Also, characteristic C3 shown by a dashed line in FIG. 5 indicates the output characteristic of battery 120d when the SOC of battery 120d is higher than characteristic C2. As shown by characteristics C2 and C3, the output characteristic of battery 120d according to the temperature of battery 120d changes according to the SOC of battery 120d, and even if the temperature of battery 120d is the same, the higher the SOC, the greater the output of battery 120d. Therefore, the temperature range TbA-TbB of battery 120d in which battery 120d can output the target battery output becomes larger as the SOC becomes higher.

For this reason, the temperature range acquisition unit 162b may acquire the temperature range TbA-TbB according to the current SOC of the battery 120d acquired by the vehicle information acquisition unit 162a. In this case, a plurality of output characteristics of the battery 120d according to the SOC, such as characteristics C1-C3, are stored in advance in the memory 164. The temperature range acquisition unit 162b selects an output characteristic corresponding to the current SOC acquired by the vehicle information acquisition unit 162a from the plurality of output characteristics stored in the memory 164, and acquires the temperature range TbA-TbB of the battery 120d within which the battery 120d can output the target battery output based on the selected output characteristic and the target battery output.

The temperature control unit 162c of the processor 162 controls the temperature of the battery 120d based on the current temperature Tb of the battery 120d and the temperature range TbA to TbB so that the temperature of the battery 120d is within the temperature range TbA to TbB by the time the vehicle 100 reaches a specific area where the use of the engine is restricted. Specifically, the temperature control unit 162c performs temperature control when the temperature Tb is outside the temperature range TbA to TbB, that is, when Tb<TbA or Tb>TbB. When Tb<TbA, the temperature control unit 162c performs heating control according to the difference between TbA and Tb (TbA-Tb) so that the larger the difference, the greater the amount of heat generated. Also, when Tb>TbB, the temperature control unit 162c performs cooling control according to the difference between Tb and TbB (Tb-TbB) so that the larger the difference, the greater the amount of cooling.

For example, the temperature control unit 162c controls the heater of the heating/cooling device 170 to perform heating control. Also, for example, the temperature control unit 162c controls the fan of the heating/cooling device 170 to perform cooling control. Since the battery 120d generates more heat as the output of the battery 120d increases, the temperature control unit 162c may perform heating control by increasing the driving amount of the power generation motor 120b or the drive motor 120c to increase the output of the battery 120d. Similarly, the temperature control unit 162c may perform cooling control by decreasing the driving amount of the power generation motor 120b or the drive motor 120c to reduce the output of the battery 120d. Note that, basically, the driving amount of the engine 120a decreases relatively as the driving amount of the motor for driving the vehicle 100 increases.

The correction unit 162d of the processor 162 corrects the amount of heat generation or cooling depending on the distance from the vehicle 10 to the boundary line 10, increasing the amount of heat generation or cooling as the distance to the boundary line 10 becomes closer. FIG. 6 is a characteristics diagram showing a map for calculating a correction coefficient by which the correction unit 162d corrects the amount of heat generation or cooling, with the horizontal axis representing the distance from the vehicle 100 to the boundary line 10 and the vertical axis representing the correction coefficient. As shown in FIG. 6, the correction coefficient is set to a larger value as the distance from the vehicle 100 to the boundary line 10 becomes shorter. If the distance from the vehicle 100 to the boundary line 10 is d1 or more, the correction coefficient is set to 0.

When Tb<TbA, the correction unit 162d corrects the amount of heat generated by multiplying the amount of heat generated according to the difference between TbA and Tb (TbA-Tb) by a correction coefficient. Therefore, the shorter the distance from the vehicle 100 to the boundary line 10, the greater the correction value of the amount of heat generated. When Tb>TbB, the correction unit 162d corrects the amount of heat generated by multiplying the amount of cooling generated according to the difference between Tb and TbB (Tb-TbB) by a correction coefficient. Therefore, the shorter the distance from the vehicle 100 to the boundary line 10, the greater the correction value of the amount of cooling generated. Note that when the distance from the vehicle 100 to the boundary line 10 is d1 or more, the correction coefficient is 0, and the amount of heat generated or the amount of cooling generated is set to 0. Therefore, in this case, no heating control or cooling control is performed.

In FIG. 6, the amount of heat generation or cooling is corrected by multiplying the amount of heat generation or cooling by a correction coefficient that has a linear relationship with the distance to the boundary line 10, but the amount of heat generation or cooling may also be corrected using a map or the like that corresponds to the distance to the boundary line 10.

When the correction unit 162d corrects the amount of heat generation or the amount of cooling, the temperature control unit 162c performs temperature control based on the corrected amount of heat generation or the amount of cooling.

The shorter the distance from the vehicle 100 to the boundary line 10, the sooner the vehicle 100 may enter the specific area inside the boundary line 10, and the sooner it becomes necessary to bring the battery 120d to an appropriate temperature. By increasing the amount of heat generation or cooling the closer the distance to the boundary line 10, the temperature of the battery 120d is reliably controlled to within the temperature range TbA to TbB by the time the vehicle 100 reaches the specific area.

In addition, the closer the distance to the boundary line 10, the higher the probability that the vehicle 100 will enter the specific area inside the boundary line 10. Depending on the distance from the vehicle 100 to the boundary line 10, the amount of heat generation or cooling is corrected to increase as the distance is closer, and more intense temperature control is implemented as the probability of the vehicle 100 entering the specific area inside the boundary line 10 increases. Therefore, control according to the probability of entering a specific area inside the boundary line 10 is possible, and temperature control is realized that takes into account the balance between ensuring battery output when the vehicle 100 enters the specific area and the decrease in energy efficiency, such as power consumption, due to heating control or cooling control.

Figure 7 is a flowchart showing the processing performed by the processor 162 of the ECU 160. The processing shown in Figure 7 is performed by the processor 162 at each predetermined control cycle. First, the vehicle information acquisition unit 162a of the processor 162 acquires the current temperature Tb of the battery 120d, the current SOC of the battery 120d, and the distance from the current position of the vehicle 100 to the boundary line 10 (step S10).

Next, the temperature range acquisition unit 162b of the processor 162 acquires the temperature range TbA to TbB of the battery 120d within which the battery 120d can output the target battery output (step S12). Next, the temperature control unit 162c of the processor 162 determines whether Tb<TbA (step S14), and if Tb<TbA, performs temperature increase control (step S16). At this time, the correction unit 162d corrects the heat generation amount to a larger value as the distance from the vehicle 100 to the boundary line 10 becomes shorter.

If Tb<TbA is not satisfied in step S14, the temperature control unit 162c determines whether Tb>TbB (step S18), and if Tb>TbB, performs cooling control (step S19). At this time, the correction unit 162d corrects the amount of cooling to a larger value as the distance from the vehicle 100 to the boundary line 10 becomes shorter. After steps S16 and S19, the processing for this control cycle ends.

As described above, according to the first embodiment, the temperature of the battery 120d is controlled to be within the temperature range TbA to TbB before the vehicle 100 reaches a specific area where the use of the engine is restricted. Therefore, when the vehicle 100 runs in EV mode using the motor as a drive source in a specific area inside the boundary line 10, a lack of driving force is suppressed.

Second Embodiment
The second embodiment relates to a case where a travel destination is set in the navigation device 150. When a travel destination is set in the navigation device 150, the driving state of the vehicle 100 to the travel destination can be predicted, and therefore the temperature and SOC of the battery 120d when the vehicle 100 reaches a specific area inside the boundary line 10 can be predicted. Therefore, the temperature control of the battery 120d can be realized with higher accuracy. In the second embodiment, the configuration of the vehicle control system mounted on the vehicle 100 is the same as that of the first embodiment shown in FIG. 2.

Figure 8 is a schematic diagram showing functional blocks of the processor 162 of the ECU 160 provided in the vehicle 100 in the second embodiment. The processor 162 has a vehicle information acquisition unit 162a, a temperature range acquisition unit 162b, a temperature control unit 162c, a correction unit 162d, and an estimation unit 162e.

As in the first embodiment, the vehicle information acquisition unit 162a of the processor 162 acquires various information such as the current temperature Tb of the battery 120d, the current SOC of the battery 120d, and the distance from the current position of the vehicle 100 to the boundary line 10. Furthermore, in the second embodiment, the vehicle information acquisition unit 162a acquires various information related to the planned travel route along which the vehicle 100 will travel from the navigation device 150.

The estimation unit 162e of the processor 162 estimates the temperature Tbe of the battery 120d when the vehicle 100 enters the specific area inside the boundary line 10, and the SOC of the battery 120d when the vehicle 100 enters the specific area inside the boundary line 10. FIG. 9 is a characteristic diagram for explaining the flow of the process in which the estimation unit 162e estimates the temperature Tbe of the battery 120d based on the planned travel route. The horizontal axis of FIG. 9 indicates time, and the vertical axis of FIG. 9 indicates the vehicle speed (FIG. 9(a)), the gradient of the road surface (FIG. 9(b)), the battery output (FIG. 9(c)), the battery loss (FIG. 9(d)), and the battery temperature (FIG. 9(e)). On the horizontal axis of FIG. 9, time t0 indicates the current time, and time t1 indicates the estimated time when the vehicle 100 enters the specific area inside the boundary line 10.

First, as shown in FIG. 9(a) and FIG. 9(b), the estimation unit 162e acquires data on the vehicle speed and gradient when the vehicle 100 travels the planned route to the travel destination from the navigation device 150. The vehicle speed may be the average vehicle speed in each section when the planned route is divided into multiple sections. The vehicle speed may also be obtained by taking real-time congestion information into consideration. The gradient is obtained from the map information of the navigation device 150. The vehicle speed and gradient data may also be obtained from history information on when the same route was traveled in the past.

9(c), the estimation unit 162e estimates the transition of the output of the battery 120d based on the data of the vehicle speed and gradient shown in FIG. 9(a) and FIG. 9(b), the running resistance of the vehicle 100, the vehicle weight, and the efficiency of energy transmission from the battery 120d to the tires. The running resistance, the vehicle weight, and the efficiency of energy transmission from the battery 120d to the tires of the vehicle 100 are set to predetermined values. Next, as shown in FIG. 9(d), the estimation unit 162e estimates the transition of the battery loss when the battery output shown in FIG. 9(c) is output. If the battery loss can be estimated, the loss becomes heat generation of the battery 120d, so as shown in FIG. 9(e), the estimation unit 162e estimates the transition of the temperature of the battery 120d based on the battery loss shown in FIG. 9(d), and estimates the temperature Tbe of the battery 120d when the vehicle 100 enters a specific area inside the boundary line 10.

Figures 10 and 11 are schematic diagrams for explaining a method of estimating the time (time t1 shown in Figure 9) when the vehicle 100 enters the specific area inside the boundary line 10. Figure 10 shows a case where the specific area defined by the boundary line 10 does not change with time. When the specific area defined by the boundary line 10 does not change with time, the estimation unit 162e estimates the time when the vehicle 100 will enter the specific area inside the boundary line 10 if it travels along the planned travel route (the route indicated by the arrow A1) based on information obtained from the navigation device 150. In the example shown in Figure 10, it is estimated that the vehicle 100 will enter the specific area inside the boundary line 10 at 7:15 AM, 30 minutes after the current time (6:45 AM).

FIG. 11 also shows a case where the specific area defined by the boundary line 10 changes depending on the time. In the example shown in FIG. 11, the boundary line 10 is changed to the boundary line 10' after 7:00 AM, and the specific area is expanded. The estimation unit 162e estimates the time at which the vehicle 100 will enter the specific area inside the boundary line 10' if it travels along the planned travel route (the route indicated by the arrow A1) based on information obtained from the navigation device 150, taking into account that the boundary line 10 will be changed to the boundary line 10' after 7:00 AM. In the example shown in FIG. 11, it is estimated that the vehicle 100 will enter the specific area inside the boundary line 10' at 7:00 AM, 15 minutes after the current time (6:45 AM).

When the estimation unit 162e estimates the time t1 when the vehicle 100 enters the specific area inside the boundary line 10, it estimates the battery temperature at time t1, i.e., the temperature Tbe when the vehicle 100 enters the specific area inside the boundary line 10, based on the battery temperature transition shown in FIG. 9(d).

The estimation unit 162e also estimates the SOC of the battery 120d when the vehicle 100 enters a specific area inside the boundary line 10 based on the current SOC of the battery 120d and the transition of the output of the battery 120d shown in FIG. 9(c).

The functions of the temperature range acquisition unit 162b, temperature control unit 162c, and correction unit 162d of the processor 162 are basically the same as those in the first embodiment. However, with regard to acquisition of the temperature range TbA-TbB based on the SOC of the battery 120d, the temperature range acquisition unit 162b in the first embodiment acquires the temperature range TbA-TbB based on the current SOC of the battery 120d, whereas the temperature range acquisition unit 162b in the second embodiment acquires the temperature range TbA-TbB based on the SOC of the battery 120d when it enters a specific area estimated by the estimation unit 162e. Note that if the SOC of the battery 120d cannot be estimated accurately, the temperature range TbA-TbB may be acquired using the current SOC as in the first embodiment.

In addition, while the temperature control unit 162c in the first embodiment controls the temperature of the battery 120d based on the current temperature Tb of the battery 120d and the temperature range TbA to TbB, the temperature control unit 162c in the second embodiment controls the temperature of the battery 120d based on the temperature Tbe estimated by the estimation unit 162e when entering a specific area and the temperature range TbA to TbB. Note that if the temperature Tbe of the battery 120d cannot be estimated accurately, the temperature may be controlled using the current temperature Tb of the battery 120d, as in the first embodiment.

In addition, while the correction unit 162d in the first embodiment corrects the amount of heat generation or the amount of cooling according to the distance from the vehicle 100 to the boundary line 10, the correction unit 162d in the second embodiment corrects the amount of heat generation or the amount of cooling according to the time it takes for the vehicle 100 to reach the boundary line 10 estimated by the estimation unit 162e, and increases the amount of heat generation or the amount of cooling the shorter the time it takes to reach the boundary line 10.

Figure 12 is a characteristic diagram showing a map for calculating a correction coefficient by which the correction unit 162d corrects the amount of heat generation or cooling, with the horizontal axis showing the time until the vehicle 100 reaches the boundary line 10 and the vertical axis showing the correction coefficient. As shown in Figure 12, the correction coefficient is set to a larger value as the time until the vehicle 100 reaches the boundary line 10 is shorter. If the time until the vehicle 100 reaches the boundary line 10 is T or longer, the correction coefficient is set to 0.

As described above, the specific area defined by the boundary line 10 may change depending on the time, so by correcting the amount of heat generation or cooling taking into account the time (time including the current time) until reaching the boundary line 10, the temperature of the battery 120d is precisely controlled to within the temperature range TbA to TbB by the time the vehicle 100 reaches the specific area, particularly when the specific area has changed.

In the second embodiment, the correction unit 162d may also correct the amount of heat generation or the amount of cooling according to the distance from the vehicle 100 to the boundary line 10. In this case, in the second embodiment, the distance that the vehicle 100 actually travels is determined based on the planned travel route, so the amount of heat generation or the amount of cooling may be corrected according to the distance that the vehicle 100 actually travels to the boundary line 10.

Figure 13 is a flowchart showing the processing performed by the processor 162 of the ECU 160. First, the vehicle information acquisition unit 162a of the processor 162 acquires the current temperature Tb of the battery 120d, the current SOC of the battery 120d, and the planned travel route (path) along which the vehicle 100 will travel (step S20).

Next, the estimation unit 162e of the processor 162 estimates the temperature Tbe of the battery 120d when the vehicle 100 enters the specific area inside the boundary line 10, and the SOC when the vehicle 100 enters the specific area inside the boundary line 10 (step S22).

Next, the temperature range acquisition unit 162b of the processor 162 acquires the temperature range TbA-TbB in which the target battery output can be output (step S24). The process of step S24 is performed in the same manner as step S12 in FIG. 7, but when acquiring the temperature range TbA-TbB taking the SOC into consideration, the temperature range acquisition unit 162b acquires the temperature range TbA-TbB based on the SOC of the battery 120d when entering the specific area estimated by the estimation unit 162e.

Next, the temperature control unit 162c of the processor 162 determines whether Tbe<TbA (step S26), and if Tbe<TbA, performs temperature increase control (step S27). At this time, the correction unit 162d corrects the heat generation amount to a larger value as the time until the vehicle 100 reaches the boundary line 10 becomes shorter.

If Tbe<TbA is not satisfied in step S26, the temperature control unit 162c determines whether Tbe>TbB (step S28), and if Tbe>TbB, performs cooling control (step S29). At this time, the correction unit 162d corrects the amount of cooling to a larger value as the time until the vehicle 100 reaches the boundary line 10 is shorter. After steps S27 and S29, the processing for this control cycle ends.

As described above, according to the second embodiment, the temperature of the battery 120d is controlled with higher accuracy based on the temperature Tbe of the battery 120d when the vehicle 100 enters the specific area inside the boundary line 10, the SOC of the battery 120d when the vehicle 100 enters the specific area inside the boundary line 10, and the time it takes for the vehicle 100 to reach the boundary line 10.

Third Embodiment
The third embodiment relates to an aspect in which, in the first or second embodiment, the temperature control of the battery 120d is not performed when the SOC of the battery 120d is low. When the temperature control of the battery 120d is performed, the power consumption of the entire vehicle control system may decrease. In particular, when the temperature control of the battery 120d is performed by heat generation according to the output of the battery 120d, the power consumption may increase due to the temperature control, and the SOC may decrease. Therefore, when the SOC of the battery 120d is low, the temperature control of the battery 120d is not performed, thereby suppressing the decrease in the SOC. This ensures a longer driving distance of the vehicle 100 when traveling in EV mode.

Figure 14 is a schematic diagram showing functional blocks of the processor 162 of the ECU 160 provided in the vehicle 100 in the third embodiment. The processor 162 has a vehicle information acquisition unit 162a, a temperature range acquisition unit 162b, a temperature control unit 162c, a correction unit 162d, an estimation unit 162e, and an SOC determination unit 162f.

The vehicle information acquisition unit 162a, temperature range acquisition unit 162b, temperature control unit 162c, correction unit 162d, and estimation unit 162e of the processor 162 are configured in the same manner as in the first or second embodiment.

The SOC determination unit 162f of the processor 162 determines whether the SOC of the battery 120d is a low SOC. If the SOC of the battery 120d is lower than a predetermined threshold, the SOC determination unit 162f determines that the SOC is low. The predetermined threshold is, for example, a value that allows the battery 120d to travel a predetermined distance (e.g., 50 km) in EV mode. Note that the current SOC or an estimated value of the SOC when the vehicle 100 enters a specific area inside the boundary line 10 may be used as the SOC of the battery 120d. The estimated value of the SOC when the vehicle 100 enters a specific area inside the boundary line 10 is estimated in the same manner as in the second embodiment.

The SOC determination unit 162f may also determine that the SOC is low when a travel destination is set in the navigation device 150 and the remaining energy amount calculated from the current SOC is less than the amount of energy required to reach the destination. In this case, the SOC determination unit 162f calculates the amount of energy required to reach the destination by integrating the battery output transition shown in FIG. 9(c) and determines whether the remaining energy amount calculated from the current SOC is less than the amount of energy required to reach the destination. Note that, when the destination is within a specific area inside the boundary line 10, the sum of the amount of energy required to travel in HV mode to reach the specific area and the amount of energy required to travel in EV mode within the specific area may be regarded as the amount of energy required to reach the destination.

If the SOC determination unit 162f determines that the SOC is low, the temperature control unit 162c of the processor 162 does not control the temperature of the battery 120d.

Figure 15 is a flowchart showing the processing performed by the processor 162 of the ECU 160, and shows an example in which temperature control according to the SOC of the battery 120d is added to the processing of the first embodiment shown in Figure 7. Note that Figure 15 differs from Figure 7 in that the processing of step S30 has been added to Figure 7. For this reason, the following description of the processing common to Figure 7 will be omitted.

After step S12, the SOC determination unit 162f of the processor 162 determines whether the SOC of the battery 120d is a low SOC (step S30). If the SOC of the battery 120d is a low SOC, the processing for this control cycle ends without performing any further processing.

On the other hand, if the SOC of battery 120d is not a low SOC in step S30, the process from step S14 onward in FIG. 7 is performed.

Note that the process in FIG. 15 shows an example in which temperature control according to SOC is added to the process of the first embodiment shown in FIG. 7, but temperature control according to SOC may also be added to the process of the second embodiment shown in FIG. 13. When temperature control according to SOC is added to the process of the second embodiment shown in FIG. 13, the process of step S30 in FIG. 15 is added after step S24 in FIG. 13.

As described above, according to the third embodiment, when the SOC of the battery 120d is low, temperature control is not performed, so that the driving distance of the vehicle 100 when traveling in EV mode is longer.

Fourth Embodiment
In the fourth embodiment, a travel destination is set in the navigation device 150, and if the amount of energy required to reach the destination cannot be secured, a process for recovering the SOC is carried out.

Figure 16 is a schematic diagram showing functional blocks of the processor 162 of the ECU 160 provided in the vehicle 100 in the fourth embodiment. The processor 162 has a vehicle information acquisition unit 162a, a temperature range acquisition unit 162b, a temperature control unit 162c, a correction unit 162d, an estimation unit 162e, an SOC determination unit 162f, and an SOC recovery unit 162g.

The vehicle information acquisition unit 162a, temperature range acquisition unit 162b, temperature control unit 162c, correction unit 162d, and estimation unit 162e of the processor 162 are configured in the same manner as in the first or second embodiment.

In the fourth embodiment, the SOC determination unit 162f of the processor 162 determines whether the SOC of the battery 120d is a low SOC based on a first threshold. Furthermore, the SOC determination unit 162f determines whether the SOC of the battery 120d is at a level that allows the vehicle to travel to the destination in EV mode based on a second threshold. Here, the second threshold is an SOC that can ensure the amount of energy required to reach the destination. On the other hand, the first threshold is an SOC that is the second threshold plus a margin. Therefore, the relationship of first threshold > second threshold is established.

The SOC recovery unit 162g of the processor 162 performs a process to recover the SOC when the SOC of the battery 120d is low and the SOC of the battery 120d is not at a level that allows the battery 120d to travel to the destination in EV mode. Specifically, the SOC recovery unit 162g performs a process to display a suggestion for recovering the SOC on the display device 180. For example, the SOC recovery unit 162g performs a process to display on the display device 180 a suggestion to pass through a charging station on the planned travel route and charge the battery at the charging station, or a suggestion to change the driving mode of the vehicle 100 to a charging mode that charges the battery 120d. Alternatively, the SOC recovery unit 162g performs a process to recover the SOC of the battery 120d by starting the engine 120a and causing the power generation motor 120b to generate electricity.

Figure 17 is a flowchart showing the processing performed by the processor 162 of the ECU 160, and shows an example in which temperature control according to the SOC of the battery 120d is added to the processing of the second embodiment shown in Figure 13. Note that Figure 17 differs from Figure 13 in that steps S30, S40, and S42 have been added to Figure 13. For this reason, the processing common to Figure 13 will not be described below.

After step S24, the SOC determination unit 162f of the processor 162 determines whether the SOC of the battery 120d is a low SOC (step S30). In step S30, the SOC determination unit 162f determines that the SOC of the battery 120d is a low SOC if the SOC is less than the second threshold. If the SOC of the battery 120d is determined to be a low SOC in step S30, the SOC determination unit 162f determines whether or not it is possible to travel in EV mode to the destination (step S40). In step S40, the SOC determination unit 162f determines that it is not possible to travel in EV mode to the destination if the SOC of the battery 120d is less than the second threshold.

If it is determined in step S40 that EV driving to the destination is not possible, the SOC recovery unit 162g of the processor 162 performs processing to recover the SOC (step S42). The SOC recovery unit 162g performs processing to display a suggestion for recovering the SOC on the display device 180, or to recover the SOC by starting the engine 120a and causing the generator motor 120b to generate electricity.

On the other hand, if the SOC of battery 120d is not a low SOC in step S30, the process from step S26 onward in FIG. 13 is performed. Also, if it is determined in step S40 that EV driving to the destination is possible, the process for this control cycle ends without performing the process of step S42.

As described above, according to the fourth embodiment, when the SOC of the battery 120d is low, temperature control is not performed, so that the vehicle 100 can travel a longer distance when traveling in EV mode. In addition, when the SOC of the battery 120d is low, processing is performed to restore the SOC, so that the SOC of the battery 120d is restored.

10 Boundary 10' Boundary 100 Vehicle 110 Positioning information receiver 120 Vehicle control device 120a Engine 120b Power generating motor 120c Driving motor 120d Battery 130 Wireless terminal 140 Sensor 150 Navigation device 160 Electronic control unit (ECU)
162 Processor 162a Vehicle information acquisition unit 162b Temperature range acquisition unit 162c Temperature control unit 162d Correction unit 162e Estimation unit 162f SOC determination unit 162g SOC recovery unit 164 Memory 166 Communication interface 170 Heating/cooling device 180 Display device 1000 Control system

Claims (1)

1. A device for controlling a temperature of a battery in a vehicle including an engine, a battery, and a motor that receives power from the battery to drive the vehicle, comprising:
a temperature range acquisition unit that acquires a temperature range of the battery in which the battery can output a predetermined output for driving the vehicle only by a driving force of the motor, the temperature range corresponding to an SOC of the battery ;
a temperature control unit that controls a temperature of the battery so that the temperature of the battery is within the temperature range before the vehicle reaches a specific area where the use of the engine is restricted;
A battery temperature control device comprising:

Images