Information processing method and information processing apparatus

Abstract

An information processing apparatus according to the present embodiment acquires noise volume information that enables specification of the volume of noise emitted by a radiator fan that cools a radiator, and uses the volume of noise specified by the acquired noise volume information to control the rotation speed of an air cooling fan that is disposed in a vehicle cabin of an electric vehicle and that cools a DC-DC converter that supplies power to a fan motor of the radiator fan.

Description

Information processing method and information processing device

[0001] This invention relates to an information processing method and an information processing apparatus.

[0002] Conventionally, attempts have been made to adjust the cooling performance of the air-cooling fan that cools the DC-DC converter in electric vehicles, hybrid vehicles, and other electric vehicles, and the quietness of the vehicle interior. For example, Patent Document 1, shown below, discloses a technology for a hybrid vehicle that aims to suppress the decrease in quietness of the vehicle interior caused by the activation of the air-cooling fan without impairing the cooling performance of the air-cooling fan, by adjusting the rotation speed of the air-cooling fan using at least one of the following elements. Specifically, Patent Document 1 discloses a technology for adjusting the rotation speed of the air-cooling fan using at least one of the following: battery temperature, DC-DC converter temperature, vehicle speed, air conditioner airflow, sound equipment volume, window open / closed state, and engine rotation speed.

[0003] Japanese Patent Publication No. 2017-105287

[0004] However, the above-described conventional technology has a problem that, for example, in the following situation, the rotational speed of the air-cooling fan increases and the quietness inside the vehicle cabin decreases. That is, when at least one of the vehicle speed, the rotational speed of the engine, and the number of steps (air volume) of the air conditioner is low, and the power consumption of the radiator fan that cools the radiator is large, there is a problem that the quietness inside the vehicle cabin decreases. As an example of such a situation, a situation where the engine water temperature has risen due to a high driving load and the vehicle speed has decreased due to traffic congestion, waiting at a signal, etc. can be cited. When the vehicle speed decreases, the driving wind blowing in from the grill decreases, so in order to cool the risen engine water temperature, the rotational speed of the radiator fan increases, that is, the power consumption of the radiator fan increases. As the power consumption of the radiator fan increases, the DC-DC converter that supplies power to the fan motor of the radiator fan needs to output a large amount of power (large current), so the temperature (internal temperature) of the DC-DC converter will rise. Then, in conjunction with the rise in the internal temperature of the DC-DC converter, the rotational speed of the air-cooling fan that cools such a DC-DC converter also increases. Since the volume of the noise generated by the air-cooling fan increases as the rotational speed of the air-cooling fan increases, in the above-described situation, the quietness inside the vehicle cabin will decrease due to the noise generated by the air-cooling fan.

[0005] On one aspect, the present invention has been made in view of such circumstances, and its object is to provide an information processing method and an information processing apparatus that appropriately cool a DC-DC converter with such an air-cooling fan while suppressing the possibility that a passenger in an electric vehicle feels uncomfortable with the noise generated by the air-cooling fan.

[0006] To solve the above-mentioned problems, an information processing method according to one aspect of the present invention is an information processing method for an electric vehicle comprising a radiator fan for cooling a radiator, a DC-DC converter for supplying power to the fan motor of the radiator fan, and an air-cooling fan located in the vehicle cabin for cooling the DC-DC converter, wherein the processor performs the steps of: acquiring noise level information that can identify the volume of noise emitted by the radiator fan; and controlling the rotation speed of the air-cooling fan, wherein the processor performs at least the step of controlling the rotation speed of the air-cooling fan using the volume of noise identified by the noise level information.

[0007] According to the present invention, it is possible to provide an information processing method and an information processing device that appropriately cool a DC-DC converter with an air-cooling fan in an electric vehicle while suppressing the possibility that the occupants may find the noise emitted by the air-cooling fan unpleasant.

[0008] This is a block diagram showing an example of the schematic configuration of a vehicle equipped with an information processing device according to the embodiment. An example of the hardware configuration of the information processing device according to the embodiment is schematically shown. An example of the software configuration of the information processing device according to the embodiment is schematically shown. An example of the processing procedure of the information processing device according to the embodiment is shown.

[0009] Hereinafter, an embodiment relating to one aspect of the present invention (hereinafter also referred to as "this embodiment") will be described based on the drawings. However, this embodiment described below is merely illustrative in all respects of the present invention. Needless to say, various improvements and modifications can be made without departing from the scope of the present invention. In other words, in carrying out the present invention, specific configurations according to the embodiment may be appropriately adopted. Although the data appearing in this embodiment is described in natural language, more specifically, it is specified in pseudo-language, commands, parameters, machine code, etc., that can be recognized by a computer.

[0010] §1 Application Example Figure 1 is a block diagram showing the schematic configuration of a vehicle VH equipped with an information processing device (information processing device 1) according to this embodiment. The vehicle VH is an example of an "electric vehicle (EV)" of the present invention, such as an electric vehicle or a hybrid vehicle, and has a power propulsion system such as an electric motor (drive motor) not shown. The vehicle VH illustrated in Figure 1 is equipped with an information processing device 1, a radiator fan control device 21, a radiator fan 23, a radiator 25, an air cooling fan control device 31, an air cooling fan 33, and a DC-DC converter 35. In the vehicle VH, at least the information processing device 1, the radiator fan control device 21, and the air cooling fan control device 31 are connected by, for example, a CAN (Controller Area Network) or other in-vehicle LAN, and can send and receive information from each other.

[0011] The radiator 25 is a heat exchanger, and for example, if the vehicle VH is realized as a hybrid vehicle, it may be a radiator that cools the coolant of the engine mounted on the hybrid vehicle, or a radiator that cools the engine oil. Alternatively, the radiator 25 may be a radiator that acts as a heat exchanger for an air conditioner to cool the interior of the vehicle VH. The radiator fan 23 is a fan that cools the radiator 25, and for example, it is an electric fan, and in this embodiment it is rotationally driven by a fan motor. The radiator fan control device 21 is a control device that controls the radiator fan 23 (the fan motor of the radiator fan 23), and for example it controls the rotation speed (rotational velocity) of the radiator fan 23. In this embodiment the radiator fan control device 21 communicates with the information processing device 1 and, for example, transmits (outputs) noise level information INL that can identify the volume of noise (noise level NL) emitted by the radiator fan 23 to the information processing device 1. Furthermore, the radiator fan control device 21 receives a radiator fan rotation instruction IRR from the information processing device 1, which instructs the rotation speed of the radiator fan 23, and controls the rotation speed of the radiator fan 23 according to the received radiator fan rotation instruction IRR.

[0012] The DC-DC converter 35 supplies power to the fan motor of the radiator fan 23. The DC-DC converter 35, for example, steps down the voltage from the drive battery (a high-voltage battery that supplies power to the drive motor of the vehicle VH) mounted on the vehicle VH and supplies power to the fan motor of the radiator fan 23. The DC-DC converter 35 may be connected between the drive battery and a low-voltage circuit (for example, a 14V circuit) to which auxiliary equipment such as accessories mounted on the vehicle VH and auxiliary batteries that power such auxiliary equipment are connected. The radiator fan 23 (especially its fan motor) may be connected to the low-voltage circuit described above. The air-cooling fan 33 is located inside the vehicle VH and is a fan that cools (air-cools) the DC-DC converter 35, and is for example, an electric fan. In this embodiment, the air-cooling fan 33 is located inside the vehicle together with the DC-DC converter 35 and cools the DC-DC converter 35 located inside the vehicle. The air-cooling fan control device 31 is a control device that controls the air-cooling fan 33, for example, by controlling the rotation speed (rotational speed) of the air-cooling fan 33. In this embodiment, the air-cooling fan control device 31 communicates with the information processing device 1 and, for example, receives an air-cooling fan rotation instruction IRA from the information processing device 1 that instructs the rotation speed of the air-cooling fan 33, and controls the rotation speed of the air-cooling fan 33 according to the received air-cooling fan rotation instruction IRA.

[0013] The information processing device 1 controls the air cooling fan 33, and in this embodiment, controls the rotation speed of the air cooling fan 33 via the air cooling fan control device 31 by transmitting (outputting) an air cooling fan rotation instruction IRA to the air cooling fan control device 31 that controls the air cooling fan 33. The information processing device 1 may further control the radiator fan 23. In the example shown in Figure 1, the information processing device 1 controls the rotation speed of the radiator fan 23 via the radiator fan control device 21 by transmitting a radiator fan rotation instruction IRR to the radiator fan control device 21 that controls the radiator fan 23 (particularly its fan motor).

[0014] In the illustrated example, the information processing device 1 controls the air-cooling fan 33 using noise level information INL received from the radiator fan control device 21. However, the information used by the information processing device 1 to control the air-cooling fan 33 is not limited to noise level information INL. The information processing device 1 may also acquire vehicle status information indicating whether or not the vehicle VH is stationary from the driving system ECU (Electronic Control Unit), which controls the driving of the vehicle VH's driving source such as the drive motor, the driving of the brakes, and the driving of the power steering. Various signals indicating the detection results detected by various sensors may be input to the information processing device 1. Such various sensors include, for example, a sensor (thermometer) for detecting the internal temperature CT of the DC-DC converter 35.

[0015] In this embodiment, the information processing device 1 controls the rotation speed of the air cooling fan 33 using at least the noise level NL of the radiator fan 23, which is identified by the noise level information INL. For example, the information processing device 1 determines the rotation speed of the air cooling fan 33 according to the noise level NL of the radiator fan 23, such that the noise emitted by the air cooling fan 33 becomes the background noise of the noise emitted by the radiator fan 23.

[0016] If the radiator fan 23 generates noise (for example, if the noise level NL of the radiator fan 23 is high), the power consumption of the radiator fan 23 (especially its fan motor) will also be high. Therefore, it is thought that the amount of heat generated by the DC-DC converter 35 that supplies power to the radiator fan 23 will also be high. In order to cool the DC-DC converter 35 in accordance with the amount of heat generated by the DC-DC converter 35, it becomes necessary to rotate the air cooling fan 33. However, since the air cooling fan 33 is located inside the passenger compartment of the vehicle VH, if the passenger compartment is quiet, the noise emitted by the air cooling fan 33, such as the operating noise (rotation noise) and the airflow noise associated with the rotation of the air cooling fan 33, may cause discomfort to the occupants (passengers) of the vehicle VH.

[0017] Therefore, the information processing device 1 determines the rotation speed of the air cooling fan 33 according to the noise level NL of the radiator fan 23, so that the noise emitted by the air cooling fan 33 becomes the background noise of the noise emitted by the radiator fan 23. For example, the information processing device 1 determines the rotation speed of the air cooling fan 33 so that the volume of noise emitted by the air cooling fan 33 is lower than the noise level NL of the radiator fan 23. As a result, the information processing device 1 can appropriately cool the DCDC converter 35 with the air cooling fan 33 while suppressing the possibility that occupants in the vehicle VH may find the noise emitted by the air cooling fan 33 unpleasant. The information processing device 1 outlined above will now be described in detail with reference to Figures 2 to 4.

[0018] §2 Configuration Example [Hardware Configuration] Figure 2 schematically shows an example of the hardware configuration of the information processing device 1 according to this embodiment. As shown in Figure 2, the information processing device 1 according to this embodiment is a computer in which a control unit 11, a storage unit 12, a communication interface 13, an external interface 14, an input device 15, an output device 16, and a drive 17 are electrically connected. In Figure 2, the communication interface and the external interface are referred to as "communication I / F" and "external I / F" respectively.

[0019] The control unit 11 includes a hardware processor such as a CPU (Central Processing Unit), RAM (Random Access Memory), and ROM (Read Only Memory), and is configured to perform information processing based on a program and various data. The CPU is an example of a processor resource. The storage unit 12 is an example of a memory resource and is composed of, for example, a hard disk drive or a solid-state drive. In this embodiment, the storage unit 12 stores various information such as an information processing program 121, a corresponding map 123, and reference temperature information 125.

[0020] The information processing program 121 is a program that causes the information processing device 1 to execute the information processing described later (Figure 4), which involves "controlling the rotation speed of the air cooling fan 33 using at least the volume of noise (noise level NL) emitted by the radiator fan 23." The information processing program 121 includes a series of instructions for said information processing.

[0021] The correspondence map 123 is a map that associates the rotational speed of the radiator fan 23 with the noise level (noise level NL) emitted by the radiator fan 23. The correspondence map 123 is prepared in advance and its contents may be updated as needed. For example, the correspondence map 123 may be prepared in advance by arbitrarily controlling the rotational speed of the radiator fan 23 in an experiment and measuring the noise level emitted by the radiator fan 23 according to the rotational speed of the radiator fan 23.

[0022] Reference temperature information 125 is information that the information processing device 1 refers to when making a determination regarding the internal temperature CT of the DC-DC converter 35, and indicates the reference temperature upper limit UTL and the reference temperature lower limit LTL. Reference temperature information 125 is prepared in advance and its contents may be updated as appropriate. For example, an experiment may be conducted in advance to measure the upper limit of the temperature at which the DC-DC converter 35 does not experience any problems such as failure, and the measured upper limit may be set as the reference temperature upper limit UTL. In other words, the reference temperature upper limit UTL may indicate a temperature at which the DC-DC converter 35 needs to be cooled immediately if the internal temperature CT of the DC-DC converter 35 exceeds the reference temperature upper limit UTL. Similarly, for example, an experiment may be conducted in advance to measure the temperature range in which the DC-DC converter 35 operates stably without any problems occurring, and the upper limit of the measured temperature range may be set as the reference temperature lower limit LTL. In other words, if the reference temperature lower limit LTL is below the reference temperature lower limit LTL to which the internal temperature CT of the DC-DC converter 35 relates, the DC-DC converter 35 may be at a temperature at which it can operate stably without cooling.

[0023] The information stored in the memory unit 12 is not limited to the information processing program 121, the corresponding map 123, and the reference temperature information 125. The memory unit 12 may also have a map (second map) pre-stored that associates the rotation speed of the air cooling fan 33 with the volume of noise emitted by the air cooling fan 33. The information processing device 1 may use this second map to determine the rotation speed of the air cooling fan 33 such that the volume of noise emitted by the air cooling fan 33 is lower than the noise level NL of the radiator fan 23. The information processing device 1 may also use the second map to determine the rotation speed of the air cooling fan 33 according to the noise level NL of the radiator fan 23 such that the noise emitted by the air cooling fan 33 becomes the background noise of the noise emitted by the radiator fan 23. For example, the second map may be prepared in advance by arbitrarily controlling the rotation speed of the cooling fan 33 in an experiment and measuring the volume of noise emitted by the cooling fan 33 according to its rotation speed.

[0024] The communication interface 13 is, for example, a wired LAN (Local Area Network) module, a wireless LAN module, etc., and is an interface for wired or wireless communication over a network. As described above, the communication interface 13 may also be an interface for communication over a CAN or other in-vehicle LAN. The information processing device 1 may use this communication interface 13 to perform data communication over a network with other information processing devices. The external interface 14 is, for example, a USB (Universal Serial Bus) port, a dedicated port, etc., and is an interface for connecting to external devices. The type and number of external interfaces 14 may be appropriately selected according to the type and number of external devices to be connected. The information processing device 1 is connected to, for example, a radiator fan control device 21, an air cooling fan control device 31, a drive system ECU, and a sensor for detecting the internal temperature CT of the DC-DC converter 35, etc., via at least one of the communication interface 13 and the external interface 14.

[0025] The input device 15 is a device for inputting data, such as a mouse or keyboard. The output device 16 is a device for outputting data, such as a display or speaker. Users or other operators can operate the information processing device 1 by using the input device 15 and the output device 16.

[0026] The drive 17 is, for example, a CD drive, a DVD drive, etc., and is a drive device for reading various information such as programs stored in the storage medium 91. The storage medium 91 is a medium that stores information such as programs by electrical, magnetic, optical, mechanical, or chemical means so that computers and other devices, machines, etc., can read the stored information such as programs. At least one of the above-mentioned information processing program 121, correspondence map 123, reference temperature information 125, and second map may be stored in the storage medium 91. The information processing device 1 may acquire the information processing program 121, correspondence map 123, reference temperature information 125, and at least one of the second map from this storage medium 91. In Figure 2, a disk-type storage medium such as a CD or DVD is shown as an example of the storage medium 91. However, the type of storage medium 91 is not limited to disk type and may be other types. Examples of storage media other than disk type include semiconductor memory such as flash memory. The type of drive 17 may be arbitrarily selected according to the type of storage medium 91.

[0027] Regarding the specific hardware configuration of the information processing device 1, components can be omitted, replaced, and added as appropriate depending on the embodiment. For example, the processor resources may include multiple hardware processors. Hardware processors may consist of microprocessors, FPGAs (field-programmable gate arrays), DSPs (digital signal processors), etc. The storage unit 12 may consist of RAM and ROM included in the control unit 11. At least one of the communication interface 13, external interface 14, input device 15, output device 16, and drive 17 may be omitted. The information processing device 1 may consist of multiple computers. In this case, the hardware configuration of each computer may or may not be the same. Furthermore, the information processing device 1 may be an information processing device designed specifically for the services provided, or it may be a general-purpose server device, a PC (Personal Computer), etc.

[0028] [Software Configuration] Figure 3 schematically illustrates an example of the software configuration of the information processing device 1 according to this embodiment. The control unit 11 of the information processing device 1 loads the information processing program 121 stored in the storage unit 12 into the RAM. The control unit 11 then uses the CPU to interpret and execute the instructions contained in the information processing program 121 loaded into the RAM, thereby controlling each component. As a result, as shown in Figure 3, the information processing device 1 according to this embodiment operates as a computer equipped with a noise level information acquisition unit 110, a noise level calculation unit 120, an air cooling fan control unit 130, a temperature information acquisition unit 140, a temperature determination unit 150, a vehicle stopping determination unit 160, and a radiator fan control unit 170 as software modules. In other words, in this embodiment, each software module of the information processing device 1 is implemented by the control unit 11 (CPU).

[0029] The noise level information acquisition unit 110 acquires noise level information INL that can identify the noise level NL of the radiator fan 23. In this embodiment, the noise level information acquisition unit 110 acquires radiator fan rotation speed information IRF, which indicates the rotation speed of the radiator fan 23, as noise level information INL. The noise level information acquisition unit 110 acquires radiator fan rotation speed information IRF, for example, by communicating with the radiator fan control device 21 that controls the rotation speed of the radiator fan 23.

[0030] The noise level calculation unit 120 identifies (calculates) the noise level NL of the radiator fan 23 from the noise level information INL acquired by the noise level information acquisition unit 110. In this embodiment, the noise level calculation unit 120 identifies the noise level NL of the radiator fan 23 from the radiator fan rotation speed information IRF acquired by the noise level information acquisition unit 110 from the radiator fan control device 21 and the corresponding map 123. For example, the noise level calculation unit 120 first refers to the storage unit 12 to acquire the corresponding map 123 which associates the rotation speed of the radiator fan 23 with the noise level NL. Then, the noise level calculation unit 120 identifies the noise level NL of the radiator fan 23 from the rotation speed of the radiator fan 23 indicated by the radiator fan rotation speed information IRF and the corresponding map 123.

[0031] It is not essential for the information processing device 1 to acquire radiator fan rotation speed information IRF as noise level information INL. Furthermore, it is not essential for the information processing device 1 to identify the noise level NL of the radiator fan 23 from the corresponding map 123 and the radiator fan rotation speed information IRF. For example, if the vehicle VH is equipped with a sound level meter capable of measuring the volume of noise emitted by the radiator fan 23 (noise level NL), the information processing device 1 may acquire noise level information INL indicating the noise level NL measured by such a sound level meter. However, by identifying the noise level NL of the radiator fan 23 from the corresponding map 123 and the radiator fan rotation speed information IRF, the information processing device 1 achieves the following effect: That is, the information processing device 1 can identify the noise level NL of the radiator fan 23 from the rotation speed of the radiator fan 23 and the corresponding map 123 without requiring the aforementioned sound level meter. The information processing device 1 can determine the noise level NL of the radiator fan 23 from the rotation speed of the radiator fan 23 and the corresponding map 123, without incurring the cost required to install the above-mentioned sound level meter on the vehicle VH.

[0032] In particular, in this embodiment, the information processing device 1 acquires radiator fan rotation speed information IRF, which indicates the rotation speed of the radiator fan 23, from the radiator fan control device 21, which controls the rotation speed of the radiator fan 23. Therefore, the information processing device 1 can determine the noise level NL of the radiator fan 23 from the radiator fan rotation speed information IRF acquired from the radiator fan control device 21 and the corresponding map 123. The information processing device 1 can determine the noise level NL of the radiator fan 23 from the radiator fan rotation speed information IRF acquired from the radiator fan control device 21 and the corresponding map 123 without incurring the cost of installing a sensor (for example, an encoder) to measure the rotation speed of the radiator fan 23 in the vehicle VH.

[0033] The air-cooling fan control unit 130 controls the rotation speed of the air-cooling fan 33. In particular, the air-cooling fan control unit 130 controls the rotation speed of the air-cooling fan 33 using at least the noise level NL of the radiator fan 23, which is determined by the noise level calculation unit 120. In addition to the noise level NL of the radiator fan 23, the air-cooling fan control unit 130 may also control the rotation speed of the air-cooling fan 33 using the determination result of at least one of the temperature determination unit 150 and the stop determination unit 160. The air-cooling fan control unit 130 determines the rotation speed of the air-cooling fan 33 using the noise level NL determined by the noise level information INL, and transmits an air-cooling fan rotation instruction IRA to the air-cooling fan control device 31, instructing it to rotate the air-cooling fan 33 at the determined rotation speed. In the illustrated example, the air-cooling fan control unit 130 includes an air-cooling fan rotation speed determination unit 132.

[0034] The cooling fan rotation speed determination unit 132 determines the rotation speed of the cooling fan 33 using at least the noise level NL of the radiator fan 23, which is identified by the noise level calculation unit 120 from the noise level information INL (for example, radiator fan rotation speed information IRF). For example, the cooling fan rotation speed determination unit 132 determines the rotation speed of the cooling fan 33 according to the noise level NL of the radiator fan 23, such that the noise emitted by the cooling fan 33 becomes the background noise of the noise emitted by the radiator fan 23.

[0035] For example, the cooling fan speed determination unit 132 may determine the rotation speed of the cooling fan 33 using a second map that has been prepared in advance and associates the rotation speed of the cooling fan 33 with the volume of noise emitted by the cooling fan 33. The cooling fan speed determination unit 132 may also use this second map to determine the rotation speed of the cooling fan 33 according to the noise level NL of the radiator fan 23, such that the noise emitted by the cooling fan 33 becomes the background noise of the noise emitted by the radiator fan 23. For example, the cooling fan speed determination unit 132 may use the second map to determine the rotation speed of the cooling fan 33 such that the volume of noise emitted by the cooling fan 33 is lower than the noise level NL of the radiator fan 23. However, it is not essential for the cooling fan speed determination unit 132 to use the second map to determine the rotation speed of the cooling fan 33. For example, the cooling fan speed determination unit 132 may determine the rotation speed of the cooling fan 33 according to a pre-prepared logic (cooling fan speed determination logic). This cooling fan speed determination logic may determine the rotation speed of the cooling fan 33 according to the noise level NL of the radiator fan 23, such that the noise emitted by the cooling fan 33 becomes the background noise of the noise emitted by the radiator fan 23.

[0036] The temperature information acquisition unit 140 acquires converter temperature information ICT indicating the internal temperature CT of the DC-DC converter 35. For example, the temperature information acquisition unit 140 acquires converter temperature information ICT indicating the internal temperature CT detected by a sensor that detects the internal temperature CT of the DC-DC converter 35.

[0037] The temperature determination unit 150 compares the internal temperature CT of the DCDC converter 35, indicated by the converter temperature information ICT acquired by the temperature information acquisition unit 140, with the reference temperature upper limit value UTL and the reference temperature lower limit value LTL indicated by the reference temperature information 125. In the illustrated example, the temperature determination unit 150 includes a first temperature determination unit 152 and a second temperature determination unit 154.

[0038] The first temperature determination unit 152 determines whether the internal temperature CT of the DC-DC converter 35 exceeds the reference temperature upper limit UTL. For example, the first temperature determination unit 152 first refers to the storage unit 12 to obtain reference temperature information 125. Then, the first temperature determination unit 152 compares the reference temperature upper limit UTL indicated by the obtained reference temperature information 125 with the internal temperature CT of the DC-DC converter 35 indicated by the converter temperature information ICT. The first temperature determination unit 152 notifies the air cooling fan control unit 130 and the radiator fan control unit 170 of the comparison result.

[0039] If the first temperature determination unit 152 determines that "the internal temperature CT of the DC-DC converter 35 exceeds the reference temperature upper limit value UTL", the cooling fan control unit 130 may increase the rotation speed of the cooling fan 33 regardless of the noise level NL indicated by the noise level information INL. As described above, the reference temperature upper limit value UTL indicates a temperature at which the DC-DC converter 35 needs to be cooled urgently, for example, when the internal temperature CT of the DC-DC converter 35 exceeds the reference temperature upper limit value UTL. Therefore, if the information processing device 1 determines that the internal temperature CT of the DC-DC converter 35 exceeds the reference temperature upper limit value UTL, it increases the rotation speed of the cooling fan 33 regardless of the noise level NL of the radiator fan 23 and cools the DC-DC converter 35 with the cooling fan 33. Thus, the information processing device 1 can properly cool the DC-DC converter 35 with the cooling fan 33 so that no problems such as failures occur in the DC-DC converter 35. Furthermore, the information processing device 1 can prevent situations such as the power supply to auxiliary equipment being restricted due to overheating of the DC-DC converter 35, thereby limiting the use of such auxiliary equipment by the occupants of the vehicle VH.

[0040] The second temperature determination unit 154 determines whether the internal temperature CT of the DC-DC converter 35 is below the reference temperature lower limit LTL. For example, the second temperature determination unit 154 first refers to the storage unit 12 to obtain reference temperature information 125. Then, the second temperature determination unit 154 compares the reference temperature lower limit LTL indicated by the obtained reference temperature information 125 with the internal temperature CT of the DC-DC converter 35 indicated by the converter temperature information ICT. The second temperature determination unit 154 notifies the air cooling fan control unit 130 of the comparison result.

[0041] If the second temperature determination unit 154 determines that "the internal temperature CT of the DC-DC converter 35 is below the reference temperature lower limit LTL", the cooling fan control unit 130 may reduce the rotation speed of the cooling fan 33 regardless of the noise level NL indicated by the noise level information INL. As described above, the reference temperature lower limit LTL indicates the temperature at which the DC-DC converter 35 can operate stably without cooling, for example, when the internal temperature CT of the DC-DC converter 35 is below the reference temperature lower limit LTL. Therefore, if the information processing device 1 determines that the internal temperature CT of the DC-DC converter 35 is below the reference temperature lower limit LTL, it reduces the rotation speed of the cooling fan 33 regardless of the noise level NL of the radiator fan 23. Therefore, the information processing device 1 can suppress noises emitted by the cooling fan 33, such as the driving noise of the cooling fan 33 and the airflow noise associated with the rotation of the cooling fan 33, thereby improving the quietness inside the vehicle cabin. In addition, by reducing the rotation speed of the cooling fan 33, the information processing device 1 can suppress the power consumption of the cooling fan 33, thereby improving the driving range, fuel efficiency, and electric power consumption of the vehicle VH.

[0042] The stopping determination unit 160 determines whether or not the vehicle VH is stopped. For example, the stopping determination unit 160 obtains vehicle status information from the running system ECU indicating whether or not the vehicle VH is stopped, and uses the obtained vehicle status information to determine whether or not the vehicle VH is stopped. The stopping determination unit 160 notifies the air cooling fan control unit 130 and the radiator fan control unit 170 of the determination result.

[0043] The radiator fan control unit 170 controls the rotational speed of the radiator fan 23. In particular, the radiator fan control unit 170 controls the rotational speed of the radiator fan 23 using the comparison result by the first temperature determination unit 152 and the determination result by the stop determination unit 160. That is, when the stop determination unit 160 determines that "the vehicle VH is stopped" and the first temperature determination unit 152 determines that "the internal temperature CT of the DC-DC converter 35 exceeds the reference temperature upper limit value UTL", the radiator fan control unit 170 rotates the radiator fan 23. In the present embodiment, the radiator fan control unit 170 rotates the radiator fan 23 by transmitting a radiator fan rotation instruction IRR for instructing the rotation of the radiator fan 23 to the radiator fan control device 21.

[0044] After the radiator fan 23 is rotated by the radiator fan control unit 170, the air-cooling fan control unit 130 may rotate the air-cooling fan 33 using the noise volume NL of the radiator fan 23. For example, after the rotation of the radiator fan 23 is started, the air-cooling fan control unit 130 determines the rotational speed of the air-cooling fan 33 so that the volume of the noise generated by the air-cooling fan 33 is smaller than the noise volume NL of the radiator fan 23, and rotates the air-cooling fan 33 at the determined rotational speed.

[0045] That is, when the vehicle VH is stopped and the internal temperature CT of the DC-DC converter 35 exceeds the reference temperature upper limit value UTL, the information processing device 1 may first rotate the radiator fan 23. Then, after rotating the radiator fan 23, the information processing device 1 may determine the rotational speed of the air-cooling fan 33 according to the noise volume NL of the radiator fan 23 and rotate the air-cooling fan 33 at the determined rotational speed. For example, the information processing device 1 may determine the rotational speed of the air-cooling fan 33 according to the noise volume NL of the radiator fan 23 so that the noise generated by the air-cooling fan 33 becomes the background noise of the noise generated by the radiator fan 23.

[0046] While the vehicle VH is stationary, the passenger compartment is quiet. Therefore, when the air-cooling fan 33 is rotated, noises emitted by the air-cooling fan 33, such as the driving sound of the air-cooling fan 33 and the airflow sound associated with the rotation of the air-cooling fan 33, may cause discomfort to the passengers of the vehicle VH. Thus, when the vehicle VH is stationary and the internal temperature CT of the DC-DC converter 35 exceeds the reference temperature upper limit value UTL, the information processing device 1 first rotates the radiator fan 23. Then, after starting the rotation of the radiator fan 23, the information processing device 1 determines the rotational speed of the air-cooling fan 33 such that the noise emitted by the air-cooling fan 33 becomes the background noise of the noise emitted by the radiator fan 23, and rotates the air-cooling fan 33 at the determined rotational speed. Therefore, the information processing device 1 can appropriately cool the DC-DC converter 35 with the air-cooling fan 33 while suppressing the possibility that the passengers of the stationary vehicle VH feel discomfort from the noise emitted by the air-cooling fan 33.

[0047] §3 Operating Example FIG. 4 is a flowchart showing an example of the processing procedure of the information processing device 1 according to the present embodiment. The processing procedure described below is an example of the processing procedure of the information processing method PM of "controlling the rotational speed of the air-cooling fan 33 using at least the volume of the noise (noise volume NL) emitted by the radiator fan 23". However, the processing procedure described below is merely an example, and each step may be changed as much as possible. Furthermore, with respect to the processing procedure described below, omission, substitution, and addition of steps are possible as appropriate according to the embodiment.

[0048] (Step S110) In step S110, the control unit 11 operates as a noise volume information acquisition unit 110 and acquires noise volume information INL that can specify the volume of the noise (noise volume NL) emitted by the radiator fan 23. In step S110, the control unit 11 may acquire radiator fan rotation speed information IRF indicating the rotational speed of the radiator fan 23 as the noise volume information INL. For example, the radiator fan rotation speed information IRF may be acquired by communicating with the radiator fan control device 21.

[0049] (Step S120) In step S120, the control unit 11 operates as a noise level calculation unit 120 and identifies (calculates) the noise level NL of the radiator fan 23 from the noise level information INL acquired in step S110. In step S120, the control unit 11 may identify the noise level NL of the radiator fan 23 from, for example, the radiator fan rotation speed information IRF acquired in step S110 and the corresponding map 123 stored in the storage unit 12. That is, the control unit 11 first acquires the corresponding map 123, for example by referring to the storage unit 12. Then, the control unit 11 may identify the noise level NL of the radiator fan 23 from the acquired corresponding map 123 and the rotation speed of the radiator fan 23 indicated by the radiator fan rotation speed information IRF acquired as noise level information INL in step S110.

[0050] (Step S130) In step S130, the control unit 11 operates as a temperature information acquisition unit 140 and acquires converter temperature information ICT indicating the internal temperature CT of the DC-DC converter 35. In step S130, the control unit 11 may also acquire converter temperature information ICT indicating the internal temperature CT detected by a sensor that detects the internal temperature CT of the DC-DC converter 35, for example.

[0051] (Step S140) In step S140, the control unit 11 operates as a temperature determination unit 150 (in particular, a first temperature determination unit 152) and determines whether the internal temperature CT of the DC-DC converter 35, indicated by the converter temperature information ICT acquired in step S130, exceeds the reference temperature upper limit UTL. In step S140, the control unit 11, for example, obtains reference temperature information 125 by referring to the storage unit 12, and compares the reference temperature upper limit UTL indicated by the acquired reference temperature information 125 with the internal temperature CT of the DC-DC converter 35 indicated by the converter temperature information ICT. If it is determined that the internal temperature CT of the DC-DC converter 35 exceeds the reference temperature upper limit UTL (Yes in S140), the control unit 11 proceeds to step S150. If it is determined that the internal temperature CT of the DC-DC converter 35 does not exceed the reference temperature upper limit UTL (No in S140), the control unit 11 proceeds to step S160.

[0052] (Step S150) In step S150, the control unit 11 operates as the air cooling fan control unit 130 and increases the rotational speed of the air cooling fan 33. In step S150, the control unit 11 increases the rotational speed of the air cooling fan 33 regardless of the noise level NL of the radiator fan 23 identified in step S120, for example.

[0053] (Step S160) In step S160, the control unit 11 operates as a temperature determination unit 150 (particularly a second temperature determination unit 154) and determines whether the internal temperature CT of the DC-DC converter 35, indicated by the converter temperature information ICT acquired in step S130, is below the reference temperature lower limit LTL. In step S160, the control unit 11 acquires reference temperature information 125 by referring to the storage unit 12, for example, and compares the reference temperature lower limit LTL indicated by the acquired reference temperature information 125 with the internal temperature CT of the DC-DC converter 35 indicated by the converter temperature information ICT. If it is determined that the internal temperature CT of the DC-DC converter 35 is below the reference temperature lower limit LTL (Yes in S160), the control unit 11 proceeds to step S170. If it is determined that the internal temperature CT of the DC-DC converter 35 is not below the reference temperature lower limit LTL (No in S160), the control unit 11 proceeds to step S180.

[0054] (Step S170) In step S170, the control unit 11 operates as the air cooling fan control unit 130 and reduces the rotational speed of the air cooling fan 33. In step S170, the control unit 11 reduces the rotational speed of the air cooling fan 33 regardless of the noise level NL of the radiator fan 23, for example, which was identified in step S120.

[0055] (Step S180) In step S180, the control unit 11 operates as an air cooling fan control unit 130 and rotates the air cooling fan 33 at a rotational speed corresponding to the noise level NL of the radiator fan 23 identified in step S120. In step S180, the control unit 11 first determines the rotational speed of the air cooling fan 33 according to the noise level NL of the radiator fan 23, such that the noise emitted by the air cooling fan 33 becomes the background noise of the noise emitted by the radiator fan 23. Then, the control unit 11 rotates the air cooling fan 33 at the determined rotational speed.

[0056] If the answer to S140 is Yes, the control unit 11 may further execute the "step of determining whether or not the vehicle VH is stationary." For example, the control unit 11 may acquire vehicle status information from the running system ECU indicating whether or not the vehicle VH is stationary, and use the acquired vehicle status information to determine whether or not the vehicle VH is stationary. If it determines that the vehicle VH is stationary, the control unit 11 may further execute the "step of rotating the radiator fan 23," and then execute step S180. In other words, if the control unit 11 determines that the vehicle VH is stationary and that the internal temperature CT of the DCDC converter 35 is above the reference temperature upper limit UTL, it may first rotate the radiator fan 23. After starting to rotate the radiator fan 23, the control unit 11 may determine the rotation speed of the air cooling fan 33 according to the noise level NL of the radiator fan 23, and rotate the air cooling fan 33 at the determined rotation speed. For example, the control unit 11 may determine the rotational speed of the air cooling fan 33 according to the noise level NL of the radiator fan 23, such that the noise emitted by the air cooling fan 33 becomes the background noise of the noise emitted by the radiator fan 23.

[0057] [Features] As described above, the information processing device 1 according to this embodiment is an information processing device included in a vehicle VH (electric vehicle). The vehicle VH includes a radiator fan 23 that cools a radiator 25, a DC-DC converter 35 that supplies power to the fan motor of the radiator fan 23, and an air-cooling fan 33 located inside the vehicle VH that cools the DC-DC converter 35. The information processing device 1 includes a noise level information acquisition unit 110 and an air-cooling fan control unit 130. The noise level information acquisition unit 110 acquires noise level information INL that can identify the volume of noise (noise level NL) emitted by the radiator fan 23. The air-cooling fan control unit 130 controls the rotation speed of the air-cooling fan 33. In particular, the air-cooling fan control unit 130 controls the rotation speed of the air-cooling fan 33 using at least the noise level NL of the radiator fan 23 identified by the noise level information INL acquired by the noise level information acquisition unit 110.

[0058] The information processing method PM according to this embodiment is an information processing method that causes a processor in a vehicle VH to perform the process of "controlling the rotation speed of the air cooling fan 33 using at least the volume of noise (noise level NL) emitted by the radiator fan 23." The information processing method PM causes a processor (for example, the control unit 11 of the information processing device 1) to perform steps S110 and S180 as illustrated in Figure 4. In step S110, the processor acquires noise level information INL that can identify the noise level NL of the radiator fan 23. In step S180, the processor controls the rotation speed of the air cooling fan 33, and in particular, controls the rotation speed of the air cooling fan 33 using at least the noise level NL of the radiator fan 23 identified by the noise level information INL acquired in step S110.

[0059] The information processing device 1 (information processing method PM) determines the rotation speed of the air cooling fan 33 according to the noise level NL of the radiator fan 23, such that the noise emitted by the air cooling fan 33 becomes the background noise of the noise emitted by the radiator fan 23. For example, the information processing device 1 (information processing method PM) determines the rotation speed of the air cooling fan 33 such that the volume of noise emitted by the air cooling fan 33 is lower than the noise level NL of the radiator fan 23. As a result, the information processing device 1 (information processing method PM) can appropriately cool the DC-DC converter 35 with the air cooling fan 33 in the vehicle VH while suppressing the possibility that occupants may find the noise emitted by the air cooling fan 33 unpleasant.

[0060] §4 Modifications While embodiments of the present invention have been described in detail above, the descriptions above are merely illustrative of the present invention in all respects. It goes without saying that various improvements or modifications can be made without departing from the scope of the present invention. For example, the following modifications are possible. In the following, the same reference numerals are used for components similar to those in the above embodiments, and explanations of similar points are omitted as appropriate. The following modifications can be combined as appropriate.

[0061] In the above embodiment, an example was described in which the information processing device 1, the radiator fan control device 21, and the air cooling fan control device 31 are each configured by separate computers. However, the configuration of the information processing device 1 according to this embodiment is not limited to this example and may be determined as appropriate depending on the embodiment. For example, the information processing device 1 and at least one of the radiator fan control device 21 and the air cooling fan control device 31 may be implemented as a single computer.

[0062] 1...Information processing device, 11...Control unit (processor), 21...Radiator fan control device, 23...Radiator fan, 25...Radiator, 33...Air cooling fan, 35...DC-DC converter, 110...Noise level information acquisition unit, 123...Corresponding map (map), 130...Air cooling fan control unit, CT...Internal temperature, ICT...Converter temperature information, INL...Noise level information, IRF...Radiator fan rotation speed information, LTL...Reference temperature lower limit, PM...Information processing method, UTL...Reference temperature upper limit, VH...Vehicle (electric vehicle)

Claims

1. An electric vehicle comprising: a radiator fan for cooling a radiator; a DC-DC converter for supplying power to the fan motor of the radiator fan; and an air-cooling fan located inside the vehicle cabin for cooling the DC-DC converter, wherein the processor performs the steps of: acquiring noise level information that can identify the volume of noise emitted by the radiator fan; and controlling the rotational speed of the air-cooling fan, wherein the step of controlling the rotational speed of the air-cooling fan is at least using the volume of noise identified by the noise level information.

2. The information processing method according to claim 1, wherein the processor further performs the steps of: acquiring converter temperature information indicating the internal temperature of the DCDC converter; determining whether the internal temperature indicated by the converter temperature information exceeds a reference temperature upper limit, and if it determines that the internal temperature exceeds the reference temperature upper limit, the processor increases the rotation speed of the cooling fan in the step of controlling the rotation speed of the cooling fan, regardless of the volume of the noise indicated by the noise level information.

3. The information processing method according to claim 2, wherein the processor further performs the step of determining whether the internal temperature indicated by the converter temperature information is below a reference temperature lower limit, and if it determines that the internal temperature is below the reference temperature lower limit, the processor, in the step of controlling the rotation speed of the cooling fan, reduces the rotation speed of the cooling fan regardless of the noise level indicated by the noise level information.

4. The information processing method according to claim 2 or 3, wherein the processor further performs the step of determining whether the electric vehicle is stationary, and if it determines that the electric vehicle is stationary and the internal temperature is above the reference temperature upper limit, the processor performs the step of rotating the radiator fan, and after performing the step of rotating the radiator fan, the processor performs the step of controlling the rotation speed of the air cooling fan, and rotates the air cooling fan.

5. The information processing method according to claim 1 or 2, wherein the processor further performs the step of obtaining a pre-prepared map which associates the rotational speed of the radiator fan with the volume of the noise emitted by the radiator fan; the processor obtains radiator fan rotational speed information indicating the rotational speed of the radiator fan as noise volume information; and the processor identifies the volume of the noise from the rotational speed of the radiator fan indicated by the radiator fan rotational speed information and the map.

6. The information processing method according to claim 5, wherein the processor obtains radiator fan rotation speed information indicating the rotation speed of the radiator fan by communicating with a radiator fan control device that controls the rotation speed of the radiator fan.

7. An information processing device included in an electric vehicle comprising: a radiator fan for cooling a radiator; a DC-DC converter for supplying power to the fan motor of the radiator fan; and an air-cooling fan located inside the vehicle cabin for cooling the DC-DC converter, comprising: a noise level information acquisition unit for acquiring noise level information capable of identifying the volume of noise emitted by the radiator fan; and an air-cooling fan control unit for controlling the rotational speed of the air-cooling fan, wherein the air-cooling fan control unit controls the rotational speed of the air-cooling fan using at least the volume of noise identified by the noise level information acquired by the noise level information acquisition unit.

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