Vehicle air-conditioning control method and vehicle air-conditioning control device

Abstract

To accurately grasp the amount of water vapor in a vehicle cabin and thereby allow an air-conditioning device to appropriately perform anti-fogging operation for preventing a windshield from fogging up.SOLUTION: A vehicle air-conditioning control method acquires a first parameter related to the amount of water vapor entering a vehicle cabin 21 formed by a windshield 22 and a vehicle cabin forming panel (roof panel 23) and the amount of water vapor coming out from the vehicle cabin, acquires a second parameter related to condensation generated on the vehicle cabin forming panel in the vehicle cabin, and calculates the amount of water vapor inside the vehicle cabin based on the first parameter and the second parameter. An air-conditioning device 3 configured to blow conditioned air into the vehicle cabin performs, based on the amount of water vapor, anti-fogging operation for the windshield.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The technology disclosed herein relates to a vehicle air conditioning control method and a vehicle air conditioning control device.

Background Art

[0002] Patent Document 1 describes a conventional air conditioner. The air conditioner is mounted on a vehicle equipped with an internal combustion engine. The air conditioner heats while switching between an internal air circulation mode and an outside air introduction mode so that the windshield does not fog up.

[0003] More specifically, the air conditioner includes a dew point temperature acquisition means and a glass temperature acquisition means. The dew point temperature acquisition means is installed on the vehicle interior side of the windshield and acquires the dew point temperature from the temperature and relative humidity of the air near the surface of the windshield. The glass temperature acquisition means is installed on the vehicle interior side of the windshield and acquires the glass temperature on the vehicle interior side surface of the windshield.

[0004] When the dew point temperature exceeds the glass temperature, window fogging occurs on the windshield. When the dew point temperature exceeds a temperature threshold set to a value slightly lower than the glass temperature or with a margin, the air conditioner switches from the internal air circulation mode to the outside air introduction mode. Since outside air with less water vapor is introduced into the vehicle interior, the dew point temperature decreases as the relative humidity decreases.

[0005] Patent Document 2 describes a conventional vehicle in which a water-absorbing anti-fog film is laminated on the vehicle interior side surface of the front window. The anti-fog film suppresses fogging of the front window by absorbing moisture adhering to the film surface inside.

[0006] When the water absorption amount of the anti-fog film reaches the saturated moisture amount, the air conditioner performs an anti-fog operation to dehydrate the anti-fog film. Specifically, the air conditioner switches to the outside air introduction mode and blows outside air toward the front window. Since the water absorption function of the anti-fog film is restored by the anti-fog operation of the air conditioner, the anti-fog performance of the front window is maintained.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0008] The outside air introduction mode reduces the heating efficiency because it introduces low-temperature outside air. It is required of the air conditioner to reduce the switching frequency to the outside air introduction mode as much as possible within the range where fogging of the front window can be prevented.

[0009] Different from the conventional air conditioner described above, an air conditioner mounted on a vehicle without an internal combustion engine, for example, a BEV (Battery Electric Vehicle), warms the air blown into the vehicle interior by an electric heater. In the air conditioner of a BEV, the outside air introduction mode significantly increases the power consumption. For the air conditioner of a BEV, it is required to further reduce the switching frequency to the outside air introduction mode in order to improve the power consumption performance of the BEV.

[0010] On the other hand, the conventional air conditioner uses a sensor that measures the relative humidity inside the vehicle cabin. A sensor for measuring humidity generally has a risk of low measurement accuracy in a specific situation. For example, it is in a situation where the air volume of the conditioned air blown near the front window is low and / or the temperature of the conditioned air is low. Considering the low measurement accuracy of humidity, it is difficult for the conventional air conditioner to reduce the switching frequency to the outside air introduction mode in maintaining anti-fogging of the front window.

[0011] Also, in a conventional vehicle having the above-described anti-fog film with water absorption, the water absorption amount of the anti-fog film is determined based on the measured value of the in-vehicle humidity sensor. Considering the low measurement accuracy of humidity, in a conventional air conditioner, the frequency of anti-fog operation involving switching to the outside air introduction mode becomes high.

[0012] The technology disclosed herein appropriately executes anti-fog operation for suppressing fogging of the front window in an air conditioner by accurately grasping the amount of water vapor in the vehicle interior.

Means for Solving the Problem

[0013] The technology disclosed herein relates to an air conditioning control method for a vehicle. This air conditioning control method acquires a first parameter related to the amount of water vapor entering the vehicle interior formed by the front window and the vehicle interior forming panel and the amount of water vapor exiting the vehicle interior, acquires a second parameter related to dew condensation occurring on the vehicle interior forming panel in the vehicle interior, calculates the amount of water vapor in the vehicle interior based on the first parameter and the second parameter, and based on the amount of water vapor, an air conditioner that blows conditioned air into the vehicle interior executes anti-fog operation for the front window.

[0014] By the air conditioner that blows conditioned air into the vehicle interior executing anti-fog operation for the front window, fogging of the front window is suppressed.

[0015] In this air conditioning control method, a first parameter is acquired. The first parameter is a parameter related to the amount of water vapor entering the vehicle interior and the amount of water vapor exiting the vehicle interior.

[0016] Also, in this air conditioning control method, for calculating the amount of water vapor in the vehicle interior, a second parameter related to dew condensation occurring on the vehicle interior forming panel is acquired. This is because when dew condensation occurs on the vehicle interior forming panel, the amount of water vapor in the vehicle interior decreases by the amount of the dew condensation.

[0017] The amount of water vapor in the vehicle interior is calculated based on a first parameter and a second parameter. Since no humidity sensor is used, erroneous measurement of the humidity in the vehicle interior by the humidity sensor can be avoided. Further, since the second parameter is considered in the calculation of the amount of water vapor, that is, it is considered that the amount of water vapor in the vehicle interior decreases due to dew condensation generated on the vehicle interior forming panel, the amount of water vapor in the vehicle interior can be accurately calculated.

[0018] Since the amount of water vapor in the vehicle interior can be accurately obtained, the air conditioner can appropriately execute an anti-fogging operation for suppressing fogging of the front window. Appropriate execution of the anti-fogging operation improves, for example, the power consumption performance or fuel consumption performance of the vehicle by suppressing unnecessary execution of the anti-fogging operation.

[0019] The second parameter may be a parameter related to dew condensation generated on the roof panel, in a space between the roof panel as the vehicle interior forming panel and an interior member located closer to the vehicle interior side than the roof panel.

[0020] The space between the roof panel and the interior member has weak air flow, and the roof panel is cooled by the running wind. Therefore, dew condensation is likely to occur on the roof panel, and the amount of dew condensation on the roof panel may be relatively large.

[0021] On the other hand, the space between the roof panel and the interior member generally communicates with the space inside the interior member, that is, the space in the vehicle interior partially formed by the front window. Therefore, the dew condensation on the roof panel has a high correlation with the amount of water vapor in the space in the vehicle interior.

[0022] The fact that the second parameter is a parameter related to dew condensation generated on the roof panel enables accurate calculation of the amount of water vapor in the vehicle interior.

[0023] The second parameter is related to the amount of dew condensation generated on the vehicle interior forming panel, and it may be that the greater the amount of dew condensation, the smaller the amount of water vapor in the vehicle interior is calculated.

[0024] The greater the amount of dew condensation generated on the passenger compartment forming panel, the smaller the amount of water vapor in the passenger compartment. There is a high correlation between the amount of dew condensation generated on the passenger compartment forming panel and the amount of water vapor in the passenger compartment. Using a second parameter related to the amount of dew condensation generated on the passenger compartment forming panel in the calculation of the amount of water vapor in the passenger compartment improves the calculation accuracy of the amount of water vapor in the passenger compartment.

[0025] The second parameter related to the amount of dew condensation may be obtained by processing a photographed image of the passenger compartment forming panel on which dew condensation has occurred.

[0026] For example, a specific pattern with a large difference in brightness and darkness is printed on the surface of the passenger compartment forming panel. When dew condensation occurs on the passenger compartment forming panel, the appearance of the specific pattern, that is, the difference in brightness and darkness, changes due to the scattering of light caused by the dew condensation. By processing the photographed image of the passenger compartment forming panel on which dew condensation has occurred, a second parameter related to the amount of dew condensation generated on the passenger compartment forming panel can be obtained based on the change in the difference in brightness and darkness.

[0027] Note that the specific pattern may be printed on the entire passenger compartment forming panel or on a part thereof.

[0028] A printed matter with a specific pattern printed thereon may be attached to the photographed location of the passenger compartment forming panel. In this case, the printed matter is photographed. When the printed matter is used, it is also possible that a high thermal conductivity material is interposed between the passenger compartment forming panel and the printed matter.

[0029] A temperature difference occurring between the printed matter attached to the passenger compartment forming panel and the passenger compartment forming panel may reduce the calculation accuracy of the amount of water vapor. This is because when the temperature of the printed matter and the temperature of the passenger compartment forming panel are different, the amount of dew condensation generated on the printed matter does not match the amount of dew condensation generated on the passenger compartment forming panel other than the printed matter.

[0030] The high thermal conductivity material between the passenger compartment forming panel and the printed matter reduces or eliminates the temperature difference between the passenger compartment forming panel and the printed matter. The amount of dew condensation generated on the printed matter and the amount of dew condensation generated on the passenger compartment forming panel other than the printed matter are the same or almost the same. The second parameter regarding the amount of dew condensation obtained by photographing the dew condensation generated on the printed matter reflects the amount of dew condensation occurring throughout the passenger compartment forming panel. The high thermal conductivity material enables accurate calculation of the amount of water vapor in the passenger compartment.

[0031] The first parameter may include the ventilation volume in the passenger compartment, the space volume in the passenger compartment, the number of passengers, and the absolute humidity of the outside air.

[0032] The ventilation volume in the passenger compartment, the space volume in the passenger compartment, the number of passengers, and the absolute humidity of the outside air are related to the amount of water vapor entering the passenger compartment and the amount of water vapor exiting the passenger compartment, and contribute to the accurate estimation of the amount of water vapor in the passenger compartment.

[0033] When the dew point based on the amount of water vapor exceeds the temperature of the front window, the air conditioner may execute anti-fogging operation.

[0034] When the dew point based on the amount of water vapor in the passenger compartment exceeds the temperature of the front window, the front window may become fogged. By the air conditioner executing anti-fogging operation, fogging of the front window is suppressed.

[0035] The front window has a water-absorbing anti-fogging film. When the amount of water absorbed by the anti-fogging film calculated based on the amount of water vapor exceeds the saturated moisture content of the anti-fogging film, the air conditioner may execute anti-fogging operation.

[0036] The water-absorbing anti-fogging film suppresses dew condensation on the surface of the front window (and the surface of the anti-fogging film) by absorbing moisture. When the amount of water absorbed by the anti-fogging film exceeds the saturated moisture content of the anti-fogging film, the anti-fogging film can no longer absorb more water. Dew condensation occurs on the surface of the anti-fogging film, fogging the front window. By the air conditioner executing anti-fogging operation, fogging of the front window is suppressed.

[0037] The air conditioner may perform at least one of increasing the air volume, raising the temperature, and increasing the outside air ratio of the conditioned air blown toward the front window as an anti-fog operation.

[0038] If at least one of increasing the air volume, raising the temperature, and increasing the outside air ratio of the conditioned air blown toward the front window is performed, the dew point of the air near the front window will drop, or the surface temperature of the glass will rise, thus suppressing the fogging of the front window.

[0039] Also, when the front window has an anti-fog film, if at least one of increasing the air volume, raising the temperature, and increasing the outside air ratio of the conditioned air blown toward the front window is performed, the anti-fog film will dehydrate. Since the water absorption function of the anti-fog film is restored, the fogging of the front window is suppressed.

[0040] The vehicle air conditioning control device disclosed herein includes an air conditioner that blows conditioned air into the vehicle interior formed by the front window and the vehicle compartment forming panel, and a controller that causes the air conditioner to perform an anti-fog operation on the front window. The controller acquires a first parameter related to the amount of water vapor in the vehicle interior and a second parameter related to the dew condensation generated on the vehicle compartment forming panel in the vehicle interior, and the controller also calculates the amount of water vapor in the vehicle interior based on the first parameter and the second parameter, and causes the air conditioner to perform an anti-fog operation on the front window based on the amount of water vapor.

[0041] Since the controller can accurately calculate the amount of water vapor in the vehicle interior based on the first parameter and the second parameter, the air conditioner can appropriately perform an anti-fog operation to suppress the fogging of the front window. The appropriate execution of the anti-fog operation improves the power consumption performance or fuel consumption performance of the vehicle.

Advantages of the Invention

[0042] The above-described vehicle air-conditioning control method and air-conditioning control device can appropriately execute the anti-fogging operation.

Brief Description of the Drawings

[0043]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Modes for Carrying Out the Invention

[0044] Hereinafter, embodiments of a vehicle air conditioning control method and an air conditioning control device will be described with reference to the drawings. The air conditioning control method and the air conditioning control device described herein are examples.

[0045] [First Embodiment] (Configuration of Air Conditioning Control Device) FIG. 1 shows a vehicle 2 equipped with an air conditioning control device 1. The vehicle 2 is, for example, a BEV that does not have an internal combustion engine and in which a driving motor is driven by the power of a battery to run. The vehicle 2 to which the technology disclosed herein is applicable is not limited to a BEV. The vehicle 2 may be a PHEV (Plug-in Hybrid Electric Vehicle) equipped with an internal combustion engine. The vehicle 2 may also be an HEV (Hybrid Electric Vehicle) or an ICE (Internal Combustion Engine) vehicle that runs by the driving force of an internal combustion engine.

[0046] The passenger compartment 21 of the vehicle 2 is formed by a front window 22 and a passenger compartment forming panel. The passenger compartment forming panel includes at least a roof panel 23, a door panel 24, and a floor panel 25. An interior member 26 is located on the passenger compartment side of the roof panel 23. The interior member 26 forms the ceiling portion inside the passenger compartment 21. A space 27 is formed between the roof panel 23 and the interior member 26. In this embodiment, the space 27 is a part of the passenger compartment 21. The space 27 communicates with the inside of the passenger compartment 21 partially formed by the front window 22.

[0047] The vehicle 2 is equipped with an air conditioner 3. The air conditioner 3 performs air conditioning in the passenger compartment 21 by blowing conditioned air into the passenger compartment 21.

[0048] The air conditioner 3 has a case 30. The case 30 has a defroster outlet 31 and a passenger compartment outlet 32. The defroster outlet 31 blows conditioned air along the surface of the front window 22 facing the passenger compartment 21, as indicated by the dashed arrow in FIG. 1. The passenger compartment outlet 32 blows conditioned air inward of the passenger compartment 21 where the passenger P is seated.

[0049] The air conditioner 3 has a defroster outlet door 33 and a passenger compartment outlet door 34. The defroster outlet door 33 opens and closes the defroster outlet 31. The passenger compartment outlet door 34 opens and closes the passenger compartment outlet 32.

[0050] The case 30 has an outside air inlet 35 and an internal air circulation port 36. As shown by the solid arrow in FIG. 1, the outside air inlet 35 introduces the air outside the passenger compartment 21 into the case 30. As shown by the broken arrow in FIG. 1, the internal air circulation port 36 introduces the air inside the passenger compartment 21 into the case 30.

[0051] The air conditioner 3 has a switching valve 37. The switching valve 37 adjusts the opening degrees of the outside air inlet 35 and the internal air circulation port 36 (see the double-ended arrow in FIG. 1). When the opening degree of the outside air inlet 35 increases by the switching valve 37, the opening degree of the internal air circulation port 36 decreases, and when the opening degree of the outside air inlet 35 decreases, the opening degree of the internal air circulation port 36 increases. The switching valve 37 adjusts the ratio of the outside air and the ratio of the internal air in the conditioned air blown into the passenger compartment 21.

[0052] The air conditioner 3 has a blower 38. The blower 38 is located inside the case 30. When the blower 38 operates, the air introduced into the case 30 from the outside air inlet 35 and / or the internal air circulation port 36 is blown out from the defroster outlet 31 or the passenger compartment outlet 32.

[0053] The air conditioner 3 has a heater 39. The heater 39 is located downstream of the blower 38 inside the case 30. The heater 39 warms the air blown out from the defroster outlet 31 or the passenger compartment outlet 32. The heater 39 mounted on the vehicle 2 which is a BEV is an electric heater. The battery supplies power to the electric heater.

[0054] FIG. 2 is a block diagram of the air conditioning control device 1. The air conditioning control device 1 has a control unit 4. The control unit 4 is an example of a controller. The control unit 4 includes a microcomputer having a processor and a memory, and a storage unit 41. The storage unit 41 stores various information used for the anti-fog operation of the air conditioner 3 described later. The control unit 4 realizes the functions described later by the microcomputer while using the information stored in the storage unit 41.

[0055] The air conditioning control device 1 is provided with various sensors. The various sensors include an occupant number sensor 51, an outside air absolute humidity sensor 52, a temperature sensor 53, and a dew condensation amount sensor 54.

[0056] The occupant number sensor 51 measures the number of people riding in the vehicle 2. The occupant number sensor 51 is, for example, a load sensor attached to the seat or a sensor that detects the wearing of a seat belt.

[0057] The outside air absolute humidity sensor 52 measures the absolute humidity of the outside air outside the passenger compartment 21.

[0058] As shown in FIG. 1, the temperature sensor 53 is located on the front window 22 and measures the temperature of the front window 22.

[0059] (Structure of the dew condensation amount sensor) The dew condensation amount sensor 54 is related to the acquisition of parameters related to the amount of dew condensation generated on the roof panel 23. As shown in FIG. 1, the dew condensation amount sensor 54 is located in the space 27 between the roof panel 23 and the interior member 26. FIG. 3 shows the dew condensation amount sensor 54. The dew condensation amount sensor 54 has a camera module 55. The camera module 55 has a lens and an image sensor that converts the light passing through the lens into an electrical signal and outputs it. The dew condensation amount sensor 54 photographs the vehicle compartment side surface of the roof panel 23. The dew condensation amount sensor 54 has a lighting 56. This is because the space 27 is dark. The lighting 56 illuminates at least the imaging area of the camera module 55 on the vehicle compartment side surface of the roof panel 23.

[0060] Here, a specific pattern 57 is provided in at least the imaging area of the camera module 55 on the passenger compartment side surface of the roof panel 23. The specific pattern 57 is a pattern with a large contrast between light and dark, and as illustrated in FIG. 3, it may be a grid. Note that the specific pattern is not limited to a grid. The specific pattern 57 may be directly printed on the passenger compartment side surface of the roof panel 23.

[0061] The illumination 56 illuminates the specific pattern 57. The camera module 55 images the specific pattern 57. When no condensation occurs on the roof panel 23, as shown in the upper diagram of FIG. 3, the contrast between light and dark of the image of the specific pattern 57 imaged by the camera module 55 is large. As shown in the lower diagram of FIG. 3, when condensation 28 occurs on the roof panel 23, since the condensation scatters light, the contrast between light and dark of the image of the specific pattern 57 imaged by the camera module 55 is small.

[0062] The control unit 4 processes a signal from the condensation amount sensor 54, that is, an image of the specific pattern 57 imaged by the camera module 55, and determines the amount of condensation occurring on the roof panel 23 based on the contrast between light and dark of the image. The upper diagram of FIG. 4 illustrates the relationship between the contrast between light and dark of the image and the amount of condensation. When the contrast between light and dark of the image is large, the amount of condensation is small. When the contrast between light and dark of the image is small, the amount of condensation is large. Note that the relationship between the contrast between light and dark of the image and the amount of condensation is not necessarily a linear relationship as shown in the upper diagram of FIG. 4.

[0063] FIG. 5 shows a modification related to the dew condensation amount sensor 54. The specific pattern 57 of the roof panel 23 may be attached to the passenger compartment side surface of the roof panel 23 with a printed matter 58 having the specific pattern printed thereon, instead of directly printing on the roof panel 23. A high thermal conductivity material 59 is interposed between the roof panel 23 and the printed matter 58. In addition to the function of attaching the printed matter 58 to the roof panel 23, the high thermal conductivity material 59 has a function of making the temperature of the roof panel 23 and the temperature of the printed matter 58 the same or substantially the same. If the temperature of the roof panel 23 and the temperature of the printed matter 58 are the same or substantially the same, the amount of dew condensation generated on the printed matter 58 and the amount of dew condensation generated on the roof panel 23 other than the printed matter 58 will be the same or substantially the same. The amount of dew condensation obtained by the camera module 55 photographing the dew condensation generated on the printed matter 58 reflects the amount of dew condensation generated throughout the roof panel 23. By using the high thermal conductivity material 59, as will be described later, the control unit 4 can accurately calculate the amount of water vapor in the passenger compartment 21 based on the signal of the dew condensation amount sensor 54.

[0064] (Calculation of the amount of water vapor in the passenger compartment) The air conditioning control method and the air conditioning control device 1 disclosed herein can accurately calculate the amount of water vapor in the passenger compartment 21. Accurate calculation of the amount of water vapor enables appropriate execution of the anti-fogging operation by the air conditioning device 3. Appropriate execution of the anti-fogging operation suppresses deterioration of the power consumption performance of the vehicle 2. Note that the anti-fogging operation is an operation of the air conditioning device 3 for suppressing fogging of the front window 22.

[0065] As shown in FIG. 2, the control unit 4 has, as functional blocks, an absolute humidity prediction unit 42, a dew point calculation unit 43, and an anti-fogging determination unit 44.

[0066] The absolute humidity prediction unit 42 calculates the amount of water vapor in the passenger compartment 21 and predicts the absolute humidity in the passenger compartment 21 based on the calculated amount of water vapor. The absolute humidity prediction unit 42 uses, for the calculation of the amount of water vapor, the signals of the passenger number sensor 51, the outside air absolute humidity sensor 52, and the dew condensation amount sensor 54, and information on the ventilation volume of the air in the passenger compartment 21.

[0067] As shown in Fig. 1, the signal of the passenger number sensor 51 is related to the amount of exhaled water vapor Vp discharged into the passenger compartment 21 by the exhalation of the passenger P. The larger the number of passengers, the larger the amount of exhaled water vapor Vp.

[0068] The signal of the outside air absolute humidity sensor 52 is related to the amount of water vapor Vin of the outside air entering the passenger compartment 21. The amount of outside air water vapor Vin is also related to the ventilation volume of the air in the passenger compartment 21. The ventilation volume of the air in the passenger compartment 21 is related to the outside / inside air ratio and the blower stage number of the air conditioner 3, and the amount of exhaust water vapor Vout from the passenger compartment 21. The outside / inside air ratio is the ratio of the outside air introduced into the passenger compartment 21 through the outside air inlet 35 and the inside air circulating in the passenger compartment 21 through the inside air circulation port 36, and is related to the ratio of the opening degrees of the outside air inlet 35 and the inside air circulation port 36 by the switching valve 37. The blower stage number is related to the flow rate of the conditioned air blown into the passenger compartment 21 through the defroster outlet 31 and / or the passenger compartment outlet 32.

[0069] The signal of the dew condensation amount sensor 54 is related to the dehumidification amount Vc of the air in the passenger compartment 21. The signal of the dew condensation amount sensor 54 is related to the amount of dew condensation generated on the roof panel 23 as described above. The dew condensation on the roof panel 23 reduces the water vapor in the passenger compartment 21. The lower diagram in Fig. 4 shows the relationship between the amount of dew condensation generated on the roof panel 23 and the dehumidification amount Vc. The larger the amount of dew condensation, the larger the dehumidification amount Vc. The relationship between the amount of dew condensation and the dehumidification amount Vc, or the relationship between the brightness difference of the image of the dew condensation amount sensor 54 and the dehumidification amount Vc, may be set based on the actually measured values measured in advance. Note that the relationship between the amount of dew condensation and the dehumidification amount Vc is not limited to a linear relationship. The storage unit 41 stores the relationship between the brightness difference and the amount of dew condensation shown in Fig. 4, and the relationship between the amount of dew condensation and the dehumidification amount Vc. The storage unit 41 may store the relationship between the brightness difference of the image of the dew condensation amount sensor 54 and the dehumidification amount Vc.

[0070] The amount of water vapor Wair in the passenger compartment 21 is calculated by the following formula (1) from the difference between the amount of water vapor entering the passenger compartment 21 and the amount of water vapor leaving the passenger compartment 21. Here, V0 is the existing amount of water vapor in the passenger compartment 21. Wair = V0 + Vp + Vin - Vout - Vc ···(1) Here, FIG. 6 compares the estimated value (solid line in FIG. 6) of the amount of water vapor in the passenger compartment 21 estimated according to formula (1) with the actually measured value of the amount of water vapor in the passenger compartment 21. Formula (1) can accurately estimate the amount of water vapor in the passenger compartment 21. The dashed line in FIG. 6 shows the estimated value of the amount of water vapor when the dehumidification amount Vc term in formula (1) is omitted. When not considering the dew condensation amount generated on the roof panel 23, the estimated water vapor amount in the passenger compartment 21 is more than the actual water vapor amount. In other words, the dew condensation occurring on the roof panel 23 has a great influence on the amount of water vapor in the passenger compartment 21. Considering the dehumidification amount Vc based on the signal of the dew condensation amount sensor 54 makes it possible to accurately estimate the amount of water vapor in the passenger compartment 21.

[0071] The absolute humidity prediction unit 42 predicts the absolute humidity of the passenger compartment 21 from the amount of water vapor Wair in the passenger compartment 21 calculated according to formula (1) and the information on the volume of the passenger compartment 21. Note that the storage unit 41 stores the information on the volume of the passenger compartment 21.

[0072] The dew point calculation unit 43 calculates the dew point based on the absolute humidity in the passenger compartment 21 predicted by the absolute humidity prediction unit 42.

[0073] The anti-fog determination unit 44 determines whether anti-fog operation of the air conditioner 3 is necessary. The anti-fog determination unit 44 determines based on the dew point calculated by the dew point calculation unit 43 and the signal of the temperature sensor 53. As described above, the temperature sensor 53 measures the temperature of the front window 22. When the temperature of the front window 22 is lower than the dew point, the anti-fog determination unit 44 determines that anti-fog operation is necessary because the front window 22 may become foggy. If the anti-fog determination unit 44 determines that anti-fog operation is necessary, the control unit 4 instructs the air conditioner 3 to execute anti-fog operation.

[0074] As anti-fog operation, the air conditioner 3 (1) Increases the air volume of the conditioned air blown toward the front window 22 by increasing the blower stage number, (2) Increases the temperature of the conditioned air blown toward the front window 22 by increasing the flow rate through the heater 39. By adjusting the angle of the switching valve 37, the outside air ratio is increased. At least one of the following is executed.

[0075] By performing the anti-fog operation of the air conditioner 3, the dew point of the air near the front window 22 is lowered, or the surface temperature of the glass is raised. As a result, fogging of the front window 22 is suppressed.

[0076] (Control of the air conditioning control device) FIG. 7 is a flowchart showing the control executed by the control unit 4 and related to the control of the air conditioner 3. In step S71 after starting, the control unit 4 reads sensor values. In the subsequent step S72, the control unit 4 acquires a first parameter. The first parameter includes the ventilation volume in the passenger compartment 21, the space volume in the passenger compartment 21, the number of passengers, and the absolute humidity of the outside air. The first parameter includes V0, Vp, Vin, and Vout described above.

[0077] In step S73, the control unit 4 acquires a second parameter. The second parameter is the brightness difference of the image acquired by the dew amount sensor 54, the dew amount generated on the roof panel 23, or the dehumidification amount Vc.

[0078] In step S74, the control unit 4 calculates the absolute humidity in the passenger compartment 21 based on the first parameter and the second parameter using Equation (1) and the space volume in the passenger compartment 21.

[0079] In step S75, the control unit 4 calculates the dew point Y from the calculated absolute humidity, and in step S76, the control unit 4 acquires the temperature Tw of the front window 22 from the signal of the temperature sensor 53.

[0080] In step S77, the control unit 4 determines whether the temperature Tw is lower than the dew point Y. If the determination in step S77 is No, the control unit 4 normally operates the air conditioner 3 in step S79. If the determination in step S77 is Yes, the control unit 4 operates the air conditioner 3 in anti-fogging operation in step S78. The fogging of the front window 22 is suppressed.

[0081] The air conditioning control device 1 can avoid mismeasurement of the sensor by not using a humidity sensor for measuring the humidity inside the vehicle compartment. The air conditioning control device 1 can accurately calculate the amount of water vapor in the vehicle compartment 21. The air conditioning control device 1 can appropriately execute anti-fogging operation on the air conditioner 3.

[0082] In anti-fogging operation, as described above, the air conditioner 3 performs at least one of the following: (1) increasing the volume of the air-conditioning air blown toward the front window 22 by increasing the blower stage number; (2) increasing the temperature of the air-conditioning air blown toward the front window 22 by increasing the flow rate through the heater 39; and (3) increasing the outside air ratio by adjusting the angle of the switching valve 37. For example, the air conditioner 3 takes in a large amount of low-temperature outside air, then raises the temperature with the heater 39, and blows out the air-conditioning air toward the front window 22 at a high flow rate. Anti-fogging operation increases the power consumption of the air conditioner 3. Unnecessary anti-fogging operation degrades the power consumption performance of the BEV. Appropriate execution of anti-fogging operation realizes anti-fogging of the front window 22 while suppressing the degradation of the power consumption performance of the BEV.

[0083] The air conditioning control device 1 utilizes the amount of dew condensation generated on the roof panel 23 for calculating the amount of water vapor in the vehicle compartment 21. The space 27 between the roof panel 23 and the interior member 26 has weak air flow, and the roof panel 23 is cooled by the running wind. Therefore, dew condensation is likely to occur on the roof panel 23, and the amount of dew condensation on the roof panel 23 may be relatively large.

[0084] On the other hand, the space 27 between the roof panel 23 and the interior member 26 communicates with the space inside the passenger compartment 21, a part of which is formed by the front window 22. Therefore, the condensation on the roof panel 23 has a high correlation with the amount of water vapor in the space inside the passenger compartment 21.

[0085] Taking into account the amount of condensation generated on the roof panel 23 enables accurate calculation of the amount of water vapor in the passenger compartment 21.

[0086] Note that the air conditioning control device 1 may calculate the amount of water vapor in the passenger compartment 21 by considering the amount of condensation on the door panel 24 as a passenger compartment forming panel instead of, or in addition to, considering the amount of condensation on the roof panel 23, or by considering the amount of condensation on the floor panel 25. The door panel 24 or the floor panel 25 is also relatively likely to generate condensation between it and the interior member, and the condensation generated on these panels has a high correlation with the amount of water vapor in the space inside the passenger compartment 21.

[0087] [Second Embodiment] FIG. 8 shows a vehicle 2 equipped with the air conditioning control device 10 according to the second embodiment. In the second embodiment, the front window 22 has an anti-fog film 6. The anti-fog film 6 is attached to the surface of the front window 22 on the passenger compartment side. The anti-fog film 6 is a water-absorbent anti-fog film. The anti-fog film 6 absorbs the condensation generated in the vicinity of the front window 22. By absorbing the condensation, fogging of the front window 22 is suppressed.

[0088] When the anti-fog film 6 reaches its saturated moisture content, it can no longer absorb more moisture. When the anti-fog film 6 reaches its saturated moisture content, the air conditioner 3 dehydrates the anti-fog film 6. When the anti-fog film 6 is dehydrated, its water absorption function is restored. The anti-fog film 6 can suppress fogging of the front window 22. The anti-fog operation of the air conditioner 3 in the air conditioning control device 10 of Embodiment 2 means the dehydration operation of the anti-fog film 6.

[0089] The anti-fog film 6 obviates the need for the anti-fog operation of the air conditioner 3 in the first embodiment, that is, the operation of the air conditioner 3 that reduces the dew point of the air near the front window 22 when the temperature of the front window 22 drops below the dew point. This is because the anti-fog film 6 absorbs condensation even when the temperature of the front window 22 drops below the dew point. The frequency of the dehydration operation of the anti-fog film 6 by the air conditioner 3 is lower than the frequency of the anti-fog operation of the air conditioner 3 in the first embodiment. The anti-fog film 6 is advantageous for improving the power consumption performance of the BEV.

[0090] The air conditioning control device 10 disclosed herein can accurately calculate the amount of water vapor in the passenger compartment 21, so it can accurately determine the water absorption amount of the anti-fog film 6. Since the execution of unnecessary dehydration operation can be suppressed, the air conditioning control device 10 further improves the power consumption performance of the BEV.

[0091] FIG. 9 is a block diagram of the air conditioning control device 10. The control unit 4 has, as functional blocks, a water vapor amount prediction unit 45, a water absorption amount calculation unit 46, and a dehydration determination unit 47.

[0092] The water vapor amount prediction unit 45 calculates the amount of water vapor in the passenger compartment 21 according to the above-described formula (1). Since the dehumidification amount Vc based on the condensation amount of the roof panel 23, that is, the second parameter, is considered, the water vapor amount prediction unit 45 can accurately predict the amount of water vapor in the passenger compartment 21.

[0093] The water absorption amount calculation unit 46 calculates the water absorption amount of the anti-fog film 6. Specifically, the water absorption amount calculation unit 46 estimates the condensation amount generated near the front window 22 from the amount of water vapor in the passenger compartment 21, the saturated water vapor amount of the air near the front window 22, and the wind speed of the air conditioning air blown into the passenger compartment 21. Then, the water absorption amount calculation unit 46 calculates the water absorption amount of the anti-fog film 6 by integrating the estimated condensation amount on the assumption that the generated condensation is absorbed by the anti-fog film 6.

[0094] Note that the saturated water vapor amount of the air near the front window 22 is based on the signal of the temperature sensor 53. As described above, the temperature sensor 53 measures the temperature of the front window 22 (and the anti-fog film 6). The wind speed of the air-conditioning air is based on the blower stage number of the air conditioner 3.

[0095] Specifically, the water absorption amount calculation unit 46 estimates the dew condensation amount near the front window 22 from the following formula (2). Dew condensation amount = (Wair - Wh) × α(V) ···(2) However, Wair is the water vapor amount in the passenger compartment 21, Wh is the saturated water vapor amount of the air near the front window 22, V is the wind speed of the air-conditioning air, and α is a parameter calculated from the surface area of the front window 22 and the wind speed near the front window 22. The time integral of the dew condensation amount calculated by formula (2) is the water absorption amount of the anti-fog film 6.

[0096] The dehydration determination unit 47 determines whether dehydration of the anti-fog film 6 by the air conditioner 3 is necessary. The dehydration determination unit 47 determines based on the water absorption amount calculated by the water absorption amount calculation unit 46 and the saturated moisture amount of the anti-fog film 6. The saturated moisture amount of the anti-fog film 6 is determined by the material of the anti-fog film 6. The storage unit 41 stores the saturated moisture amount of the anti-fog film 6.

[0097] When the water absorption amount of the anti-fog film 6 exceeds the saturated moisture amount of the anti-fog film 6, the dehydration determination unit 47 determines that dehydration operation of the air conditioner 3 is necessary. If the dehydration determination unit 47 determines that dehydration operation is necessary, the control unit 4 instructs the air conditioner 3 to execute dehydration operation.

[0098] As dehydration operation, the air conditioner 3 (1) Increases the air volume of the air-conditioning air blown toward the front window 22 by increasing the blower stage number, (2) Increases the temperature of the air-conditioning air blown toward the front window 22 by increasing the flow rate through the heater 39, (3) Increases the outside air ratio by adjusting the angle of the switching valve 37, and executes at least one of the above.

[0099] Due to the dehydration operation of the air conditioner 3, the moisture absorbed by the anti-fog film 6 is released into the air, so the anti-fog film 6 is dehydrated. If the anti-fog film 6 is dehydrated, the water absorption function of the anti-fog film 6 is restored, and thus the fogging of the front window 22 is suppressed.

[0100] FIG. 10 is a flowchart of the control executed by the control unit 4 in the air conditioning control device 10 and related to the control of the air conditioner 3. In step S101 after starting, the control unit 4 reads the sensor value. In the subsequent step S102, the control unit 4 acquires the first parameter. The first parameter includes the ventilation volume in the passenger compartment 21, the space volume in the passenger compartment 21, the number of passengers, and the absolute humidity of the outside air. The first parameter includes V0, Vp, Vin, and Vout described above.

[0101] In step S103, the control unit 4 acquires the second parameter. The second parameter is the brightness difference of the image acquired by the dew condensation amount sensor 54, the dew condensation amount or dehumidification amount Vc generated on the roof panel 23.

[0102] In step S104, the control unit 4 calculates the water vapor amount Wair in the passenger compartment 21 based on the first parameter and the second parameter using Equation (1). [[ID=!]]

[0103] In step S105, the control unit 4 calculates the saturated water vapor amount Wh of the air near the front window 22 based on the signal of the temperature sensor 53. Then, in step S106, the control unit 4 calculates the water absorption amount of the anti-fog film 6 based on the water vapor amount Wair in the passenger compartment 21, the saturated water vapor amount Wh of the air near the front window 22, and the blower stage number using Equation (2), and integrates the water absorption amount.

[0104] In step S107, the control unit 4 determines whether the water absorption amount of the anti-fog film 6 exceeds the saturated moisture amount of the anti-fog film 6. If the determination in step S107 is No, the control unit 4 normally operates the air conditioner 3 in step S109. If the determination in step S107 is Yes, the control unit 4 dehydrates the air conditioner 3 in step S108. The anti-fog film 6 is dehydrated, and the fogging of the front window 22 is suppressed.

[0105] The air conditioning control device 10 can also avoid mismeasurement of the sensor by not using a humidity sensor for measuring the humidity inside the vehicle compartment. The air conditioning control device 10 can accurately calculate the amount of water vapor in the vehicle compartment 21. The air conditioning control device 10 can appropriately execute a dehydration operation on the air conditioner 3.

[0106] The air conditioning control device 10 also utilizes the amount of dew condensation generated on the roof panel 23 for calculating the amount of water vapor in the vehicle compartment 21. Considering the amount of dew condensation generated on the roof panel 23 enables accurate calculation of the amount of water vapor in the vehicle compartment 21.

[0107] The anti-fog film 6 allows a state where the amount of water vapor in the vehicle compartment 21 is high. This is because the anti-fog film 6 absorbs the dew condensation occurring near the front window 22. When the amount of water vapor in the vehicle compartment 21 is high, dew condensation is likely to occur on the surface of the roof panel 23. The dew condensation amount sensor 54 can more easily measure the amount of dew condensation generated on the roof panel 23, and the air conditioning control device 10 can calculate the amount of water vapor in the vehicle compartment 21 more accurately.

[0108] The dehydration operation, similar to the anti-fogging operation, performs at least one of the following: (1) increasing the air volume of the conditioned air blown toward the front window 22 by increasing the blower stage number; (2) increasing the temperature of the conditioned air blown toward the front window 22 by increasing the flow rate through the heater 39; (3) increasing the outside air ratio by adjusting the angle of the switching valve 37. The dehydration operation increases the power consumption of the air conditioner 3. An unnecessary dehydration operation degrades the power consumption performance of the BEV. Appropriate execution of the dehydration operation realizes anti-fogging of the front window 22 while suppressing degradation of the power consumption performance of the BEV.

[0109] Note that the air conditioning control device 10 may calculate the amount of water vapor in the passenger compartment 21 in consideration of the dew condensation amount of the door panel 24 as a passenger compartment forming panel instead of or in addition to considering the dew condensation amount of the roof panel 23, or may calculate the amount of water vapor in the passenger compartment 21 in consideration of the dew condensation amount of the floor panel 25.

Explanation of Signs

[0110] 1 Air conditioning control device 10 Air conditioning control device 21 Passenger compartment 22 Front window 23 Roof panel (passenger compartment forming panel) 24 Door panel (passenger compartment forming panel) 25 Floor panel (passenger compartment forming panel) 26 Interior member 27 Space 3 Air conditioner 4 Control unit (controller) 57 Specific pattern 58 Printed matter 59 High thermal conductivity material 6 Anti-fogging film

Claims

1. Obtain a first parameter related to the amount of water vapor entering the passenger compartment formed by the front window and the passenger compartment forming panel and the amount of water vapor exiting the passenger compartment, Obtain a second parameter related to the dew condensation generated on the passenger compartment forming panel in the passenger compartment, Calculate the amount of water vapor in the passenger compartment based on the first parameter and the second parameter, An air conditioning control method for a vehicle, wherein an air conditioner that blows conditioned air into the passenger compartment executes an anti-fogging operation of the front window based on the amount of water vapor.

2. In the air conditioning control method for a vehicle according to Claim 1, The second parameter is a parameter related to the dew condensation generated on the roof panel as the passenger compartment forming panel in a space between the roof panel and an interior member located closer to the passenger compartment side than the roof panel. An air conditioning control method for a vehicle.

3. In the air conditioning control method for a vehicle according to Claim 1 or 2, The second parameter is related to the amount of dew condensation generated on the passenger compartment forming panel, An air conditioning control method for a vehicle, wherein the amount of water vapor in the passenger compartment is calculated to be less as the amount of dew condensation increases.

4. In the air conditioning control method for a vehicle according to Claim 3, The second parameter related to the amount of dew condensation is obtained by processing a photographed image of the passenger compartment forming panel on which dew condensation has occurred. An air conditioning control method for a vehicle.

5. In the air conditioning control method for a vehicle according to Claim 4, A printed material with a specific pattern is attached to the photographed location of the passenger compartment forming panel, An air conditioning control method for a vehicle, wherein a high thermal conductivity material is interposed between the passenger compartment forming panel and the printed material.

6. In the air conditioning control method for a vehicle according to Claim 1, The first parameter includes the ventilation volume in the passenger compartment, the space volume in the passenger compartment, the number of passengers, and the absolute humidity of the outside air. An air conditioning control method for a vehicle.

7. In the air conditioning control method for a vehicle according to Claim 1, When the dew point based on the amount of water vapor exceeds the temperature of the front window, the air conditioner executes an anti-fogging operation. An air conditioning control method for a vehicle.

8. In the air conditioning control method for a vehicle according to Claim 1, The front window has a water-absorbent anti-fogging film, When the water absorption amount of the anti-fogging film calculated based on the amount of water vapor exceeds the saturated moisture amount of the anti-fogging film, the air conditioner executes an anti-fogging operation. An air conditioning control method for a vehicle.

9. In the vehicle air-conditioning control method according to claim 7 or 8, the air conditioner executes at least one of increasing the air volume, raising the temperature, and increasing the outside air ratio of the air-conditioning air blown toward the front window as an anti-fogging operation. A vehicle air-conditioning control method.

10. An air conditioner that blows air-conditioning air into the vehicle interior formed by the front window and the vehicle interior forming panel, a controller that causes the air conditioner to perform an anti-fogging operation on the front window, and the controller acquires a first parameter related to the amount of water vapor in the vehicle interior and a second parameter related to dew condensation generated on the vehicle interior forming panel in the vehicle interior, The controller also calculates the amount of water vapor in the vehicle interior based on the first parameter and the second parameter, and causes the air conditioner to perform an anti-fogging operation on the front window based on the amount of water vapor. A vehicle air-conditioning control device.

Images