Anti-fog system

Abstract

The present invention provides an anti-fog system. The system improves the efficiency of power consumption and effectively suppresses the fogging of vehicle windows. The anti-fog system (X) is provided in a vehicle (1). The vehicle (1) is provided with a photographing device (10) for photographing the space outside the vehicle from the vehicle interior through the vehicle windows. The anti-fog system (X) is provided with a first detection device (35) for detecting the riding state of passengers, a second detection device (43) for detecting the state of the vehicle interior and / or the space outside the vehicle, a third detection device (44) for detecting the driving state of the vehicle 1, an air conditioning device (20) for adjusting the air in the vehicle interior, a heating device (19) for heating the vehicle windows, and a control device (26) for controlling the heating device (19) based on the detection results of the first to third detection devices (35, 43, 44) and the operating state of the air conditioning device (20).

Description

Technical Field

[0001] The present invention relates to an anti-fogging system for suppressing fogging of vehicle windows. Background Art

[0002] Conventionally, there is known an anti-fog system for suppressing fogging of vehicle windows.

[0003] For example, Patent Document 1 discloses a vehicle window glass system, which includes: a vehicle window glass installed on a mobile body such as a vehicle; an anti-fog film provided on the indoor side surface of the vehicle window glass; a temperature sensor that detects the temperature of the indoor side surface of the vehicle window glass; a temperature and humidity sensor that detects the indoor temperature and humidity of the mobile body; a drying unit that vaporizes moisture attached to the anti-fog film; and a control unit having a circuit that estimates the time until fog is generated on the anti-fog film based on the glass temperature detected by the temperature sensor and the indoor temperature and humidity detected by the temperature and humidity sensor, and operates the drying unit based on the estimated time.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: International Publication No. 2020 / 189353 Summary of the Invention

[0007] Problems to be solved by the invention

[0008] The susceptibility of vehicle windows to fogging varies depending on various factors. For example, the greater the number of passengers, the greater the amount of water vapor released by them, making the windows more susceptible to fogging. Furthermore, the higher the vehicle speed, the more the windows are cooled by the traveling airflow, making it more likely that water vapor in the vehicle interior will condense near the windows, increasing the likelihood of fogging. Meanwhile, the greater the air volume of the air conditioner, the more effective it is at introducing outside air and dehumidifying the air, making the windows less susceptible to fogging.

[0009] In the above-mentioned prior art, the time until fogging occurs on the anti-fog film is estimated without considering these various factors. This makes it difficult to accurately estimate the time until fogging occurs on the anti-fog film. As a result, the operating time of the drying unit may be too short to suppress fogging of the anti-fog film, or the operating time of the drying unit may be too long, wasting electricity.

[0010] In view of the above background, an object of the present invention is to provide an anti-fog system that can improve power consumption efficiency and effectively suppress fogging of vehicle windows.

[0011] Means used to solve problems

[0012] In order to solve the above-mentioned problems, a certain scheme of the present invention is an anti-fog system (X), which is arranged in a vehicle (1), and the vehicle (1) has a shooting device (10) for shooting the space outside the vehicle (SP2) from the space inside the vehicle (SP1) through the window (6), wherein the anti-fog system (X) has: a first detection device (35) for detecting the riding status of the passengers; a second detection device (41, 43) for detecting the status of the space inside the vehicle and / or the space outside the vehicle; a third detection device (44) for detecting the driving status of the vehicle; an air-conditioning device (20) for adjusting the air in the space inside the vehicle; a heating device (19) for heating the window; and a control device (26) for controlling the heating device based on the detection results of the first to third detection devices and the operating status of the air-conditioning device.

[0013] According to this solution, the heating device can be controlled based on the passenger's state, the state of the vehicle interior and / or exterior, the vehicle's driving status, and the operating state of the air conditioning system. In other words, the heating device can be controlled based on various factors that change the susceptibility of the vehicle windows to fogging. This allows the heating device's operating time and output to be optimized, thereby improving power consumption efficiency and effectively suppressing window fogging.

[0014] In the above scheme, the control device may also determine the first control mode candidate of the heating device based on the detection result of the first detection device, determine the second control mode candidate of the heating device based on the detection result of the second detection device, determine the third control mode candidate of the heating device based on the detection result of the third detection device, determine the fourth control mode candidate of the heating device based on the operating state of the air-conditioning device, determine the control mode of the heating device based on the first control mode candidate to the fourth control mode candidate of the heating device, and control the heating device based on the determined control mode.

[0015] According to this aspect, the control mode of the heating device can be appropriately determined based on the control mode candidates determined for each factor causing the degree of fogging of the vehicle window to change.

[0016] In the above aspect, the control device may control the heating device through PWM control, and the first to fourth control mode candidates may each define a duty ratio of the heating device.

[0017] According to this aspect, the heating device is controlled by PWM control, thereby reducing heat loss in the heating device, thereby further improving power consumption efficiency.

[0018] In the above aspect, the control device may determine, as the control mode for the heating device, a control mode candidate having the highest duty ratio of the heating device among the first to fourth control mode candidates.

[0019] According to this aspect, the heating device can be operated so as to cope with the situation in which the vehicle windows are most likely to fog up. Therefore, fogging of the vehicle windows can be suppressed more effectively.

[0020] In the above aspect, the control device may obtain the number of passengers based on the detection result of the first detection device, and set the duty ratio of the heating device in the first control mode candidate to a larger value as the number of passengers increases.

[0021] The more passengers there are, the more water vapor they release, causing the windows to fog more easily. According to the above aspect, the duty ratio of the heating device in the first control mode candidate can be set to an appropriate value in consideration of this tendency.

[0022] In the above scheme, the vehicle may also include a front seat (4) and a rear seat (5) arranged behind the front seat, the camera captures the space outside the vehicle through the window located in front of the front seat, the control device obtains the number and position of the passengers based on the detection result of the first detection device, and determines whether the passengers other than the driver are present in the front seat based on the position of the passengers. When the passengers other than the driver are present in the front seat, the duty cycle of the heating device in the first control mode candidate is set to a larger value than when the passengers other than the driver are not present in the front seat.

[0023] When a passenger other than the driver is present in the front seat, the amount of water vapor released by the passenger increases near the window in front of the front seat compared to when no passenger other than the driver is present in the front seat, causing the window in front of the front seat to fog more easily. According to the above embodiment, the duty cycle of the heating device in the first candidate control mode can be set to an appropriate value in consideration of this tendency.

[0024] In the above scheme, the second detection device may include an outside temperature sensor (43) for detecting the temperature of the space outside the vehicle, and the control device may set the duty cycle of the heating device in the second control mode candidate to a larger value as the temperature of the space outside the vehicle is lower.

[0025] As the temperature outside the vehicle drops, the window temperature also drops. Therefore, water vapor inside the vehicle is more likely to condense near the windows, causing them to fog more easily. According to the above scheme, the duty cycle of the heating device in the second control mode candidate can be set to an appropriate value taking this tendency into account.

[0026] In the above scheme, the second detection device may include an outside temperature sensor (43) for detecting the temperature of the space outside the vehicle and an inside temperature sensor (41) for detecting the temperature of the space inside the vehicle. When the temperature of the space outside the vehicle is below a predetermined reference temperature, the smaller the temperature difference between the space inside the vehicle and the space outside the vehicle, the larger the duty cycle of the heating device in the second control mode candidate.

[0027] When the temperature outside the vehicle is relatively low, if the temperature difference between the interior and exterior is small, the temperature inside the vehicle and the windows is also estimated to be relatively low. When a passenger enters the vehicle under these conditions, the temperature inside the vehicle rises due to the passenger's body heat, temporarily increasing the temperature difference between the interior and the windows. Simultaneously, the humidity inside the vehicle rises due to the water vapor released by the passenger. Consequently, water vapor inside the vehicle tends to condense near the windows, causing them to fog. The above-described approach allows the duty cycle of the heating device in the second control mode candidate to be set to an appropriate value, taking this tendency into account.

[0028] In the above aspect, the third detection device may include a vehicle speed sensor that detects a vehicle speed, and the control device may set a larger value for the duty ratio of the heating device in the third control mode candidate as the vehicle speed increases.

[0029] As the vehicle speed increases, the windows are cooled more by the traveling wind. Therefore, water vapor in the vehicle interior is more likely to condense near the windows, causing them to fog more easily. According to the above scheme, the duty cycle of the heating device in the third control mode candidate can be set to an appropriate value taking this tendency into account.

[0030] In the above aspect, the control device may set the duty ratio of the heating device in the fourth control mode candidate to a smaller value as the air volume of the air conditioner increases.

[0031] The greater the air volume of the air conditioner, the greater the effect of introducing outside air and dehumidifying, so the windows are less likely to fog up. According to the above aspect, the duty ratio of the heating device in the fourth control mode candidate can be set to an appropriate value in consideration of this tendency.

[0032] Effects of the Invention

[0033] According to the above configuration, an anti-fog system capable of improving power consumption efficiency and effectively suppressing fogging of vehicle windows can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a perspective view showing a vehicle according to a first embodiment of the present invention.

[0035] Figure 2 It is a cross-sectional view showing a front window and its surrounding portion according to the first embodiment of the present invention.

[0036] Figure 3 This is a block diagram showing a vehicle according to the first embodiment of the present invention.

[0037] Figure 4 This is a flowchart showing the first determination process in the first embodiment of the present invention.

[0038] Figure 5 This is a waveform diagram showing each mode of the first control mode candidate according to the first embodiment of the present invention.

[0039] Figure 6 This is a flowchart showing the second determination process in the first embodiment of the present invention.

[0040] Figure 7 It is a waveform diagram showing each mode of the second control mode candidate according to the first embodiment of the present invention.

[0041] Figure 8 This is a flowchart showing the third determination process in the first embodiment of the present invention.

[0042] Figure 9 It is a waveform diagram showing each mode of the third control mode candidate according to the first embodiment of the present invention.

[0043] Figure 10 This is a flowchart showing the fourth determination process in the first embodiment of the present invention.

[0044] Figure 11 It is a waveform diagram showing each mode of the fourth control mode candidate according to the first embodiment of the present invention.

[0045] Figure 12 This is a flowchart showing the anti-fog control according to the first embodiment of the present invention.

[0046] Figure 13 This is a flowchart showing the first determination process in the second embodiment of the present invention.

[0047] Figure 14 This is a waveform diagram showing each mode of the first control mode candidate according to the second embodiment of the present invention.

[0048] Figure 15 This is a flowchart showing the second determination process in the third embodiment of the present invention.

[0049] Figure 16 It is a waveform diagram showing each mode of the second control mode candidate according to the third embodiment of the present invention.

[0050] Description of Reference Numerals

[0051] 1: Vehicle

[0052] 4: Front seat

[0053] 5: Rear seats

[0054] 6: Front window (an example of a car window)

[0055] 10: Front camera (an example of a camera)

[0056] 19: Heating device

[0057] 20: Air conditioning unit

[0058] 26: Control device

[0059] 35: Seat belt sensor (an example of the first detection device)

[0060] 41: In-vehicle temperature sensor (an example of the second detection device)

[0061] 43: External temperature sensor (an example of a second detection device)

[0062] 44: Vehicle speed sensor (an example of the third detection device)

[0063] SP1: Interior space

[0064] SP2: Exterior space

[0065] X: Anti-fog system DETAILED DESCRIPTION

[0066] (First embodiment)

[0067] Below, refer to Figures 1 to 12 A first embodiment of the present invention will be described.

[0068] Vehicle 1

[0069] First, refer to Figures 1 to 3 A vehicle 1 according to a first embodiment of the present invention will be described.

[0070] Reference Figure 1The vehicle 1 of this embodiment is an automobile. The vehicle 1 has a body 2 that is long in the front-to-back direction. An interior space SP1 is formed within the body 2, and a passenger compartment 3 is provided in the center of the interior space SP1 in the front-to-back direction. The compartment 3 is provided with, for example, a plurality of front seats 4 (driver's seat, passenger seat) and a plurality of rear seats 5 arranged behind the front seats 4. In addition, in this embodiment, two rows of seats are provided along the front-to-back direction, but in other embodiments, only one row of seats may be provided along the front-to-back direction, or three or more rows of seats may be provided along the front-to-back direction.

[0071] At the front of the vehicle body 2, a front window 6 (an example of a vehicle window) is provided in front of the front seat 4. The front window 6 is formed of glass. In other embodiments, the front window 6 may be formed of a transparent material other than glass (e.g., a transparent resin). At the rear of the vehicle body 2, a rear window 7 is provided behind the rear seat 5. On both sides of the vehicle body 2, a plurality of side doors 8 are provided to the sides of the front seat 4 and the rear seat 5, and a side window 9 is provided above each side door 8.

[0072] Reference Figure 1 、 Figure 2 , a front camera 10 (an example of a photographing device) is provided at the upper rear of the front window 6. The front camera 10 is a device that photographs the outside space SP2 (in this embodiment, the space in front of the vehicle 1) from the inside space SP1 through the front window 6. The front camera 10 is, for example, a digital camera that utilizes a solid-state imaging element such as a CCD or CMOS. The front camera 10 includes a lens that converges light incident from the front through the front window 6, and a sensor that converts the light converged by the lens into an electrical signal. In addition, Figure 2 The arrow P indicates the field of view (photographable range) of the front camera 10 .

[0073] Reference Figure 2 , the front camera 10 is mounted on the inner surface of the front window 6 via a bracket 11. The bracket 11 includes a main body 12 arranged around the front camera 10, and a cover 13 extending forward from the main body 12. The main body 12 is fixed to the inner surface of the front window 6. The cover 13 and the front window 6 together surround the space in front of the lens of the front camera 10. The cover 13 includes a bottom wall 13A extending in the left-right direction, and left and right side walls 13B extending upward from the left and right ends of the bottom wall 13A (at Figure 2 Only the right side wall 13B is shown).

[0074] Reference Figure 3The vehicle 1 includes a propulsion device 14, a braking device 15, a steering device 16, an HMI (Human Machine Interface) 17, a navigation device 18, a heating device 19, an air conditioning device 20, an occupant sensor 21, an external sensor 22, a vehicle sensor 23, and a control device 26. The heating device 19, the air conditioning device 20, the occupant sensor 21, the external sensor 22, the vehicle sensor 23, and the control device 26 constitute an anti-fog system X.

[0075] The propulsion device 14 is a device that applies driving force to the vehicle 1. The propulsion device 14 includes, for example, an internal combustion engine such as a gasoline engine or a diesel engine and / or an electric motor.

[0076] The brake device 15 is a device that applies a braking force to the vehicle 1. The brake device 15 includes, for example, a brake caliper that presses a pad against a brake rotor, and an electric cylinder that supplies a hydraulic pressure to the brake caliper.

[0077] The steering device 16 is a device that changes the steering angle of the wheels and includes, for example, a rack-and-pinion mechanism that steers the wheels and an electric motor that drives the rack-and-pinion mechanism.

[0078] The HMI 17 is a device that notifies the passenger of various information (for example, a malfunction of the heating device 19) and receives input operations from the passenger. The HMI 17 includes, for example, a touch panel, a sound generating device, an ignition switch, and the like.

[0079] The navigation device 18 is a device that provides route guidance for the vehicle 1 to the destination. The navigation device 18 includes an input device that accepts input operations from the passenger. The input device may be a part of the HMI 17 or may be provided independently of the HMI 17. The navigation device 18 stores map information. The navigation device 18 determines the current position (latitude and longitude) of the vehicle 1 based on signals received from artificial satellites. The navigation device 18 sets a route from the departure point of the vehicle 1 (e.g., the current position) to the destination based on the map information, the current position of the vehicle 1, and the destination of the vehicle 1 input by the passenger into the above-mentioned input device.

[0080] The heating device 19 is a device that suppresses fogging of the front window 6 by heating the front window 6. Figure 2 The heating device 19 is composed of a plurality of metal heating wires 28 in contact with the inner surface of the front window 6. At least a portion of the plurality of heating wires 28 can be arranged in the field of view of the front camera 10 (refer to Figure 2In other embodiments, the heating device 19 may be formed of a transparent film such as an ITO film (Indium Tin Oxide Film). In other embodiments, the heating device 19 may be built into the front window 6 or may be spaced apart and opposed to the front window 6.

[0081] Reference Figure 3 The air conditioning unit 20 regulates the air in the vehicle interior space SP1. The air conditioning unit 20 includes a duct connecting the vehicle interior space SP1 and the vehicle exterior space SP2, an evaporator and heater core disposed within the duct, a fan that creates air flow within the duct, and an electric motor that drives the fan. The air conditioning unit 20 is configured to switch between different airflow rates (fan speed) and air conditioning modes. These modes include, for example, an outside air intake mode that introduces air from the vehicle exterior space SP2 into the vehicle interior space SP1, an inside air circulation mode that circulates air within the vehicle interior space SP1, and a defrost mode that blows air toward the front window 6.

[0082] The passenger sensor 21 is a sensor for detecting the riding state of the passenger. The passenger sensor 21 includes a seat belt sensor 35 (an example of a first detection device) for detecting the wearing state of the seat belt of the passenger, and a passenger camera 36 for capturing an image of the passenger.

[0083] The external sensor 22 is a sensor that detects objects in the vehicle exterior space SP2 (eg, obstacles or dividing lines on the road of the vehicle 1 ). The external sensor 22 includes the aforementioned front camera 10 , sonar 38 , and an external camera 39 .

[0084] The vehicle sensors 23 are sensors that detect the state of the vehicle interior space SP1, the state of the vehicle exterior space SP2, the driving state of the vehicle 1, and the like. The vehicle sensors 23 include an interior temperature sensor 41 that detects the temperature of the vehicle interior space SP1 (hereinafter referred to as the "interior temperature"), an interior humidity sensor 42 that detects the humidity of the vehicle interior space SP1 (hereinafter referred to as the "interior humidity"), an exterior temperature sensor 43 (an example of a second detection device) that detects the temperature of the vehicle exterior space SP2 (hereinafter referred to as the "exterior temperature"), and a vehicle speed sensor 44 (an example of a third detection device) that detects vehicle speed.

[0085] The control device 26 is an electronic control unit composed of a CPU, ROM, RAM, etc. The control device 26 is connected to various components of the vehicle 1 via a communication network such as CAN (Controller Area Network) to control the various components of the vehicle 1 .

[0086] The control device 26 includes an outside world recognition unit 52 , a travel control unit 53 , an anti-fog control unit 54 , and a storage unit 55 .

[0087] The external environment recognition unit 52 of the control device 26 identifies the position of an object (e.g., an obstacle or a dividing line on the path of the vehicle 1) in the vehicle exterior space SP2 based on the detection results of the external environment sensor 22. For example, the external environment recognition unit 52 identifies the position of the object in front of the vehicle 1 by analyzing changes in density values in an image captured by the front camera 10.

[0088] The driving control unit 53 of the control device 26 controls the driving of the vehicle 1 based on the detection results of the external sensors 22 and the vehicle sensors 23. For example, when the vehicle speed detected by the vehicle speed sensor 44 is greater than a predetermined first threshold speed, the driving control unit 53 performs lane keeping control based on the position of the dividing line identified by the external recognition unit 52. During lane keeping control, the driving control unit 53 controls the steering system 16 so that the vehicle 1 travels at a reference position (e.g., the center of the lane widthwise) within the lane defined by the dividing line. Furthermore, when the vehicle speed detected by the vehicle speed sensor 44 is greater than a predetermined second threshold speed, the driving control unit 53 performs collision mitigation control based on the position of an obstacle identified by the external recognition unit 52. During collision mitigation control, the driving control unit 53 controls the braking system 15 to avoid or mitigate a collision between the vehicle 1 and the obstacle.

[0089] The anti-fog control unit 54 of the control device 26 controls the heating device 19 and the air conditioning device 20 to suppress fogging of the front window 6. For example, the anti-fog control unit 54 switches the air volume or air conditioning mode of the air conditioning device 20 based on the detection results of the vehicle sensor 23 or the input operation of the passenger on the HMI 17. The anti-fog control unit 54 controls the heating device 19 through PWM control based on the detection results of the vehicle sensor 23 and other factors.

[0090] The storage unit 55 of the control device 26 is composed of a memory, an HDD, etc. The storage unit 55 stores programs, tables, etc. required for controlling the vehicle 1.

[0091] <First Decision Process>

[0092] Next, refer to Figure 4 、 Figure 5 The first determination process executed by the anti-fog control unit 54 of the control device 26 will be described. The first determination process is used to determine a first control mode candidate for the heating device 19 based on the number of passengers (hereinafter referred to as the "passenger count"). The first determination process is executed, for example, immediately after the ignition switch of the vehicle 1 is turned on (immediately after the power of the heating device 19 is turned on). The following description uses the case where the vehicle 1 has a rated passenger capacity of five, but the same process can also be executed when the vehicle 1 has a rated passenger capacity of four or fewer, or six or more.

[0093] Reference Figure 4 When the first determination process is started, the anti-fog control unit 54 obtains the number of passengers based on the detection result of the seat belt sensor 35 (step ST1). In other embodiments, the anti-fog control unit 54 may also obtain the number of passengers based on the image of the passengers captured by the passenger camera 36.

[0094] Next, the anti-fog control unit 54 determines whether the number of passengers is one (step ST2 ). If the number of passengers is one (step ST2 : Yes), the anti-fog control unit 54 determines the first control mode candidate to be mode 1-1 (step ST3 ).

[0095] If the number of passengers is not one (step ST2: No), the anti-fog control unit 54 determines whether the number of passengers is two (step ST4). If the number of passengers is two (step ST4: Yes), the anti-fog control unit 54 determines the first control mode candidate as mode 1-2 (step ST5).

[0096] If the number of passengers is not 2 (step ST4: No), the anti-fog control unit 54 determines whether the number of passengers is 3 (step ST6). If the number of passengers is 3 (step ST6: Yes), the anti-fog control unit 54 determines the first control mode candidate as mode 1-3 (step ST7).

[0097] If the number of passengers is not three (step ST6: No), the anti-fog control unit 54 determines whether the number of passengers is four (step ST8). If the number of passengers is four (step ST8: Yes), the anti-fog control unit 54 determines the first control mode candidate to be mode 1-4 (step ST9). If the number of passengers is not four (step ST8: No), that is, if the number of passengers is five, the anti-fog control unit 54 determines the first control mode candidate to be mode 1-5 (step ST10).

[0098] Reference Figure 5 In the first control mode candidate modes 1-1 to 1-5, the duty ratio of the heating device 19 increases in the order of mode 1-1, mode 1-2, mode 1-3, mode 1-4, and mode 1-5. Thus, the anti-fog control unit 54 sets the duty ratio of the heating device 19 in the first control mode candidate to a larger value as the number of passengers obtained in step ST1 increases.

[0099] The more passengers there are, the more water vapor they release, which tends to fog up the front window 6. The first determination process described above allows the duty cycle of the heating device 19 in the first control mode candidate to be set to an appropriate value in consideration of this tendency.

[0100] <Second Decision Process>

[0101] Next, refer to Figure 6 、 Figure 7 The second determination process executed by the anti-fog control unit 54 will be described. The second determination process is used to determine a candidate second control mode for the heating device 19 based on the outside temperature. Furthermore, the outside temperature may vary significantly depending on the driving area or driving time of the vehicle 1. Therefore, the second determination process may be executed periodically, starting immediately after the ignition switch of the vehicle 1 is turned on (immediately after the power of the heating device 19 is turned on).

[0102] Reference Figure 6 When the second determination process starts, the anti-fog control unit 54 obtains the vehicle outside temperature based on the detection result of the vehicle outside temperature sensor 43 (step ST11).

[0103] Next, the anti-fog control unit 54 determines whether the outside temperature is higher than 0° C. (step ST12 ). If the outside temperature is higher than 0° C. (step ST12 : YES), the anti-fog control unit 54 determines the second control mode candidate as mode 2-1 (step ST13 ).

[0104] If the outside temperature is 0°C or lower (step ST12: No), the anti-fog control unit 54 determines whether the outside temperature is higher than -10°C (step ST14). If the outside temperature is higher than -10°C (step ST14: Yes), the anti-fog control unit 54 determines the second control mode candidate as mode 2-2 (step ST15).

[0105] If the outside temperature is -10°C or lower (step ST14: No), the anti-fog control unit 54 determines whether the outside temperature is higher than -20°C (step ST16). If the outside temperature is higher than -20°C (step ST16: Yes), the anti-fog control unit 54 determines the second control mode candidate as mode 2-3 (step ST17).

[0106] If the outside temperature is -20°C or lower (step ST16: No), the anti-fog control unit 54 determines whether the outside temperature is higher than -30°C (step ST18). If the outside temperature is higher than -30°C (step ST18: Yes), the anti-fog control unit 54 determines that the second control mode candidate is mode 2-4 (step ST19). If the outside temperature is -30°C or lower (step ST18: No), the anti-fog control unit 54 determines that the second control mode candidate is mode 2-5 (step ST20).

[0107] Reference Figure 7In the second control mode candidate modes 2-1 to 2-5, the duty ratio of the heating device 19 increases in the order of mode 2-1, mode 2-2, mode 2-3, mode 2-4, and mode 2-5. Thus, the lower the outside temperature obtained in step ST11, the greater the duty ratio of the heating device 19 in the second control mode candidate.

[0108] As the outside temperature drops, the temperature of the front window 6 also drops. Therefore, water vapor in the vehicle interior space SP1 is more likely to condense near the front window 6, and the front window 6 is more likely to fog. The second determination process described above takes this tendency into consideration and sets the duty ratio of the heating device 19 in the second control mode candidate to an appropriate value.

[0109] <Third Decision Process>

[0110] Next, refer to Figure 8 、 Figure 9 The third determination process executed by the anti-fog control unit 54 will be described. The third determination process is used to determine a third control mode candidate for the heating device 19 based on the vehicle speed. The vehicle speed fluctuates significantly while the vehicle 1 is traveling. Therefore, the third determination process may be executed periodically, starting immediately after the ignition switch of the vehicle 1 is turned on (immediately after the power of the heating device 19 is turned on).

[0111] Reference Figure 8 When the third determination process starts, the anti-fog control unit 54 obtains the vehicle speed based on the detection result of the vehicle speed sensor 44 (step ST21).

[0112] Next, the anti-fog control unit 54 determines whether the vehicle speed is less than 25 km / h (step ST22). If the vehicle speed is less than 25 km / h (step ST22: Yes), the anti-fog control unit 54 determines the third control mode candidate as mode 3-1 (step ST23).

[0113] If the vehicle speed is 25 km / h or higher (step ST22: No), the anti-fog control unit 54 determines whether the vehicle speed is less than 50 km / h (step ST24). If the vehicle speed is less than 50 km / h (step ST24: Yes), the anti-fog control unit 54 determines the third control mode candidate as mode 3-2 (step ST25).

[0114] If the vehicle speed is 50 km / h or higher (step ST24: No), the anti-fog control unit 54 determines whether the vehicle speed is less than 75 km / h (step ST26). If the vehicle speed is less than 75 km / h (step ST26: Yes), the anti-fog control unit 54 determines the third control mode candidate as mode 3-3 (step ST27).

[0115] If the vehicle speed is 75 km / h or higher (step ST26: No), the anti-fog control unit 54 determines whether the vehicle speed is less than 100 km / h (step ST28). If the vehicle speed is less than 100 km / h (step ST28: Yes), the anti-fog control unit 54 determines that the third control mode candidate is mode 3-4 (step ST29). If the vehicle speed is 100 km / h or higher (step ST28: No), the anti-fog control unit 54 determines that the third control mode candidate is mode 3-5 (step ST30).

[0116] Reference Figure 9 In the third control mode candidate modes 3-1 to 3-5, the duty ratio of the heating device 19 increases in the order of mode 3-1, mode 3-2, mode 3-3, mode 3-4, and mode 3-5. Thus, the anti-fog control unit 54 sets the duty ratio of the heating device 19 in the third control mode candidate to a larger value as the vehicle speed obtained in step ST21 increases.

[0117] As the vehicle speed increases, the wind chills the front window 6 more. Consequently, water vapor in the vehicle interior SP1 is more likely to condense near the front window 6, causing the front window 6 to fog more easily. The third decision process described above allows for setting the duty cycle of the heating device 19 in the third control mode candidate to an appropriate value, taking this tendency into consideration.

[0118] <Fourth Decision Process>

[0119] Next, refer to Figure 10 、 Figure 11 , the fourth decision processing performed by the anti-fog control unit 54 is explained. The fourth decision processing is a processing for determining the fourth control mode candidate of the heating device 19 based on the air volume (fan speed) of the air conditioning device 20. In addition, the air volume of the air conditioning device 20 may vary greatly depending on the driving area or driving time period of the vehicle 1. Therefore, the fourth decision processing can be performed periodically starting from just after the ignition switch of the vehicle 1 is turned on (just after the power of the heating device 19 is turned on). The following description takes the case where the air volume of the air conditioning device 20 is switched to five stages as an example, but the same processing can be performed when the air volume of the air conditioning device 20 is switched to less than four stages or more than six stages.

[0120] Reference Figure 10 When the fourth determination process starts, the anti-fog control unit 54 obtains the air volume scale of the air conditioner 20 (step ST31). The air volume scale is a set value proportional to the air volume of the air conditioner 20 and is switched based on the input operation of the passenger on the HMI 17 or the detection result of the vehicle sensor 23.

[0121] Next, the anti-fog control unit 54 determines whether the air volume scale is set to "1" (step ST32). If the air volume scale is set to "1" (step ST32: "Yes"), the anti-fog control unit 54 determines the fourth control mode candidate as mode 4-1 (step ST33).

[0122] If the air volume scale is not set to "1" (step ST32: No), the anti-fog control unit 54 determines whether the air volume scale is set to "2" (step ST34). If the air volume scale is set to "2" (step ST34: Yes), the anti-fog control unit 54 determines the fourth control mode candidate as mode 4-2 (step ST35).

[0123] If the air volume scale is not set to "2" (step ST34: No), the anti-fog control unit 54 determines whether the air volume scale is set to "3" (step ST36). If the air volume scale is set to "3" (step ST36: Yes), the anti-fog control unit 54 determines the fourth control mode candidate as mode 4-3 (step ST37).

[0124] If the air volume scale is not set to "3" (step ST36: No), the anti-fog control unit 54 determines whether the air volume scale is set to "4" (step ST38). If the air volume scale is set to "4" (step ST38: Yes), the anti-fog control unit 54 determines that the fourth control mode candidate is mode 4-4 (step ST39). If the air volume scale is not set to "4" (step ST38: No), that is, if the air volume scale is set to "5", the anti-fog control unit 54 determines that the fourth control mode candidate is mode 4-5 (step ST40).

[0125] Reference Figure 11 In the fourth control mode candidate modes 4-1 to 4-5, the duty cycle of the heating device 19 decreases in the order of mode 4-1, mode 4-2, mode 4-3, mode 4-4, and mode 4-5. Thus, the larger the air volume scale obtained in step ST31 (i.e., the greater the air volume of the air conditioner 20), the smaller the duty cycle of the heating device 19 in the fourth control mode candidate.

[0126] The greater the air volume of the air conditioner 20, the greater the effect of introducing outside air and dehumidifying, and thus the less likely the front window 6 will fog up. According to the fourth determination process described above, the duty ratio of the heating device 19 in the fourth control mode candidate can be set to an appropriate value in consideration of this tendency.

[0127] <Anti-fog control>

[0128] Next, refer to Figure 12 The anti-fog control executed by the anti-fog control unit 54 will be described. The anti-fog control is a control for suppressing fogging of the front window 6. For example, the anti-fog control is executed periodically from immediately after the ignition switch of the vehicle 1 is turned on.

[0129] When the anti-fog control is started, the anti-fog control unit 54 determines the first to fourth control mode candidates by executing the above-mentioned first to fourth determination processes (steps ST41 to ST44). In addition, when the anti-fog control is executed at a time other than immediately after the ignition switch of the vehicle 1 is turned on, the anti-fog control unit 54 may omit the first determination process by using the first control mode candidate determined in the first determination process immediately after the ignition switch of the vehicle 1 is turned on.

[0130] Next, the anti-fog control unit 54 performs a final decision process (step ST45). In the final decision process, the anti-fog control unit 54 determines the control mode of the heating device 19 based on the first to fourth control mode candidates. For example, the anti-fog control unit 54 determines the control mode candidate with the highest duty cycle of the heating device 19 among the first to fourth control mode candidates as the control mode of the heating device 19. In addition, in other embodiments, the anti-fog control unit 54 may also calculate the average value of the duty cycles of the heating device 19 among the first to fourth control mode candidates and determine the control mode of the heating device 19 in such a way that the duty cycle of the control mode of the heating device 19 is consistent with the above-mentioned average value. In addition, in other embodiments, the anti-fog control unit 54 may also weight the first to fourth control mode candidates based on a predetermined rule and determine the control mode of the heating device 19 based on the weighted first to fourth control mode candidates.

[0131] Next, the anti-fog control unit 54 executes an anti-fog process (step ST46 ). In the anti-fog process, the anti-fog control unit 54 controls the heating device 19 according to the control mode of the heating device 19 determined in the final determination process (step ST45 ) to suppress fogging of the front window 6 .

[0132] As described above, the anti-fog control unit 54 controls the heating device 19 based on the detection results of the seatbelt sensor 35, the outside temperature sensor 43, and the vehicle speed sensor 44, as well as the operating state of the air conditioner 20. This allows the heating device 19 to be controlled based on various factors that change the likelihood of fogging of the front window 6. This also allows the operating time and output of the heating device 19 to be optimized, thereby improving power consumption efficiency and effectively suppressing fogging of the front window 6.

[0133] Furthermore, the anti-fog control unit 54 determines a control mode for the heating device 19 based on the first to fourth control mode candidates for the heating device 19, and controls the heating device 19 using the determined control mode. Thus, the control mode for the heating device 19 can be appropriately determined based on the control mode candidates determined for each factor that changes the likelihood of fogging of the front window 6.

[0134] Furthermore, the anti-fog control unit 54 controls the heater 19 through PWM control. The first to fourth control mode candidates and the control mode all define the duty cycle of the heater 19. Controlling the heater 19 through PWM control in this manner can reduce heat loss in the heater 19, thereby further improving power consumption efficiency.

[0135] Furthermore, the anti-fog control unit 54 selects the control mode candidate with the highest duty ratio of the heater 19 among the first to fourth control mode candidates as the control mode for the heater 19. This allows the heater 19 to be operated to address the conditions in which the front window 6 is most susceptible to fogging. Consequently, fogging of the front window 6 can be more effectively suppressed.

[0136] (Second embodiment)

[0137] Next, refer to Figure 13 、 Figure 14 The second embodiment of the present invention will be described. The contents other than the first determination process performed by the anti-fog control unit 54 are identical to those of the first embodiment, and therefore their description is omitted. Furthermore, steps ST2 to ST4, ST6, and ST8 of the first determination process are identical to those of the first embodiment, and therefore their description is omitted.

[0138] Reference Figure 13 When the first determination process is started, the anti-fog control unit 54 obtains the number of passengers and the positions of the passengers based on the detection results of the seat belt sensor 35 (step ST1). In other embodiments, the anti-fog control unit 54 may also obtain the number of passengers and the positions of the passengers based on the images of the passengers captured by the passenger camera 36.

[0139] Next, similar to the first embodiment, the anti-fog control unit 54 executes steps ST2 to ST4. If the determination in step ST4 is "yes" (when there are two passengers), the anti-fog control unit 54 determines whether a passenger other than the driver (hereinafter referred to as a "fellow passenger") is present in the front seat 4 (step ST4A). If a fellow passenger is present in the front seat 4 (step ST4A: "yes"), the anti-fog control unit 54 determines the first control mode candidate as mode 1-2A (step ST5A). If a fellow passenger is not present in the front seat 4 (step ST4A: "no"), the anti-fog control unit 54 determines the first control mode candidate as mode 1-2B (step ST5B).

[0140] Similarly, if the determination in steps ST6 and ST8 is "yes" (when the number of passengers is 3 or 4), the anti-fog control unit 54 determines whether a fellow passenger is present in the front seat 4 (steps ST6A and ST8A). If a fellow passenger is present in the front seat 4 (steps ST6A and ST8A: "yes"), the anti-fog control unit 54 determines the first control mode candidate to be mode 1-3A or 1-4A (steps ST7A and ST9A). If a fellow passenger is not present in the front seat 4 (steps ST6A and ST8A: "no"), the anti-fog control unit 54 determines the first control mode candidate to be mode 1-3B or 1-4B (steps ST7B and ST9B).

[0141] Reference Figure 14 In Mode 1-2A and Mode 1-2B, the duty cycle of the heater 19 is greater in Mode 1-2A than in Mode 1-2B. Similarly, in Mode 1-3A and Mode 1-3B, the duty cycle of the heater 19 is greater in Mode 1-3A than in Mode 1-3B, and in Mode 1-4A and Mode 1-4B, the duty cycle of the heater 19 is greater in Mode 1-4A than in Mode 1-4B. Thus, when a fellow passenger is present in the front seat 4, the anti-fog control unit 54 sets the duty cycle of the heater 19 in the first control mode candidate to a larger value than when a fellow passenger is not present in the front seat 4.

[0142] When a fellow passenger is present in the front seat 4, the amount of water vapor released by the passenger increases near the front window 6 compared to when the fellow passenger is not present in the front seat 4, and thus the front window 6 is more likely to fog. The first determination process of the second embodiment takes this tendency into consideration and sets the duty ratio of the heating device 19 in the first control mode candidate to an appropriate value.

[0143] (Third embodiment)

[0144] Next, refer to Figure 15、 Figure 16 The third embodiment of the present invention will be described. The contents other than the second determination process executed by the anti-fog control unit 54 are the same as those of the first embodiment, and therefore description thereof will be omitted.

[0145] When the second determination process begins, the anti-fog control unit 54 obtains the vehicle's outdoor temperature based on the detection result of the vehicle's outdoor temperature sensor 43. Next, the anti-fog control unit 54 determines whether the vehicle's outdoor temperature is below a predetermined reference temperature (e.g., 10°C). In other embodiments, the reference temperature may be a temperature other than 10°C.

[0146] If the vehicle outside temperature is higher than the reference temperature, the anti-fog control unit 54 does not determine the second control mode candidate and ends the second determination process. In this case, the anti-fog control unit 54 does not operate the heating device 19.

[0147] On the other hand, when the outside temperature is below the reference temperature, the anti-fog control unit 54 obtains the temperature difference between the interior space SP1 and the exterior space SP2 (hereinafter referred to as "inside-outside temperature difference") based on the detection results of the interior temperature sensor 41 and the exterior temperature sensor 43 (step ST41).

[0148] Next, the anti-fog control unit 54 determines whether the internal and external temperature difference is less than 5° C. (step ST42 ). If the internal and external temperature difference is less than 5° C. (step ST42 : Yes), the anti-fog control unit 54 determines the second control mode candidate as mode 5-1 (step ST43 ).

[0149] If the internal and external temperature difference is 5°C or greater (step ST42: No), the anti-fog control unit 54 determines whether the internal and external temperature difference is less than 10°C (step ST44). If the internal and external temperature difference is less than 10°C (step ST44: Yes), the anti-fog control unit 54 determines the second control mode candidate as mode 5-2 (step ST45).

[0150] If the internal and external temperature difference is 10°C or greater (step ST44: No), the anti-fog control unit 54 determines whether the internal and external temperature difference is less than 15°C (step ST46). If the internal and external temperature difference is less than 15°C (step ST46: Yes), the anti-fog control unit 54 determines the second control mode candidate as mode 5-3 (step ST47).

[0151] If the internal / external temperature difference is 15°C or greater (step ST46: No), the anti-fog control unit 54 determines whether the internal / external temperature difference is less than 20°C (step ST48). If the internal / external temperature difference is less than 20°C (step ST48: Yes), the anti-fog control unit 54 determines that the second control mode candidate is mode 5-4 (step ST49). If the internal / external temperature difference is 20°C or greater (step ST48: No), the anti-fog control unit 54 determines that the second control mode candidate is mode 5-5 (step ST50).

[0152] Reference Figure 16 In the second control mode candidate modes 5-1 to 5-5, the duty ratio of the heater 19 increases in the order of mode 5-5, mode 5-4, mode 5-3, mode 5-2, and mode 5-1. Thus, when the outside temperature is below the reference temperature, the smaller the inside-outside temperature difference obtained in step ST41, the larger the duty ratio of the heater 19 in the second control mode candidate.

[0153] When the outside temperature is relatively low, and the difference between the inside and outside temperatures is small, the interior temperature and the temperature of the front window 6 are also estimated to be relatively low. When a passenger enters the vehicle 1 under these conditions, the temperature of the vehicle interior space SP1 rises due to the passenger's body heat, temporarily increasing the temperature difference between the interior space SP1 and the front window 6. Simultaneously, the humidity in the vehicle interior space SP1 also rises due to the water vapor released by the passenger. Consequently, water vapor in the vehicle interior space SP1 is more likely to condense near the front window 6, causing the front window 6 to fog. The second determination process of the third embodiment takes this trend into account and sets the duty cycle of the heating device 19 in the second control mode candidate to an appropriate value.

[0154] In the first to third embodiments described above, the anti-fog system X suppresses fogging of the front window 6. However, in other embodiments, the anti-fog system X can also suppress fogging of the rear window 7 or the side windows 9. In other words, in the first to third embodiments described above, the front camera 10 is used as an example of a camera device. However, in other embodiments, a rear camera or a side camera (not shown) can also be used as an example of a camera device.

[0155] Although specific embodiments have been described above, the present invention is not limited to the above-described embodiments and modifications, and can be widely modified.

Claims

1. An anti-fog system installed in a vehicle, the vehicle having a camera for capturing images of the space outside the vehicle through a vehicle window from the vehicle interior, characterized in that: The anti-fog system has: a first detection device for detecting a passenger's riding state; a second detection device for detecting a state of the vehicle interior space and / or the vehicle exterior space; a third detection device for detecting a driving state of the vehicle; an air conditioning device for conditioning the air in the vehicle interior; a heating device for heating the vehicle window; as well as a control device that controls the heating device based on the detection results of the first to third detection devices and the operating state of the air conditioning device, The control device determines a first control mode candidate for the heating device based on a detection result of the first detection device, determines a second control mode candidate for the heating device based on a detection result of the second detection device, determines a third control mode candidate for the heating device based on a detection result of the third detection device, determines a fourth control mode candidate for the heating device based on an operating state of the air-conditioning device, determines a control mode for the heating device based on the first to fourth control mode candidates for the heating device, and controls the heating device based on the determined control modes. The control device controls the heating device through PWM control, The first to fourth control mode candidates all define a duty cycle of the heating device. The control device obtains the number of passengers based on the detection result of the first detection device, and sets the duty ratio of the heating device in the first control mode candidate to a larger value as the number of passengers increases. The vehicle includes a front seat and a rear seat arranged behind the front seat. The camera captures the space outside the vehicle through the window in front of the front seat. The control device obtains the number and positions of the passengers based on the detection result of the first detection device, and determines whether the passengers other than the driver are present in the front seat based on the positions of the passengers. When the passengers other than the driver are present in the front seat, the duty cycle of the heating device in the first control mode candidate is set to a larger value compared to a case where the passengers other than the driver are not present in the front seat.

2. The anti-fog system according to claim 1, characterized in that: The control device determines a control mode candidate having the highest duty ratio of the heating device among the first to fourth control mode candidates as the control mode of the heating device.

3. The anti-fog system according to claim 1 or 2, characterized in that: The second detection device includes an outside temperature sensor for detecting the temperature of the space outside the vehicle. The control device sets the duty ratio of the heating device in the second control mode candidate to a larger value as the temperature of the vehicle exterior space is lower.

4. The anti-fog system according to claim 1 or 2, characterized in that: The third detection device includes a vehicle speed sensor for detecting vehicle speed. The control device sets the duty ratio of the heating device in the third control mode candidate to a larger value as the vehicle speed increases.

5. The anti-fog system according to claim 1 or 2, characterized in that: The control device sets the duty ratio of the heating device in the fourth control mode candidate to a smaller value as the air volume of the air conditioner increases.

6. An anti-fog system installed in a vehicle, the vehicle having a camera for capturing images of the space outside the vehicle through a vehicle window from the vehicle interior, characterized in that: The anti-fog system has: a first detection device for detecting a passenger's riding state; a second detection device for detecting a state of the vehicle interior space and / or the vehicle exterior space; a third detection device for detecting a driving state of the vehicle; an air conditioning device for conditioning the air in the vehicle interior; a heating device for heating the vehicle window; as well as a control device that controls the heating device based on the detection results of the first to third detection devices and the operating state of the air conditioning device, The control device determines a first control mode candidate for the heating device based on a detection result of the first detection device, determines a second control mode candidate for the heating device based on a detection result of the second detection device, determines a third control mode candidate for the heating device based on a detection result of the third detection device, determines a fourth control mode candidate for the heating device based on an operating state of the air-conditioning device, determines a control mode for the heating device based on the first to fourth control mode candidates for the heating device, and controls the heating device based on the determined control modes. The control device controls the heating device through PWM control, The first to fourth control mode candidates all define a duty cycle of the heating device. The second detection device includes an outside temperature sensor for detecting the temperature of the space outside the vehicle and an inside temperature sensor for detecting the temperature of the space inside the vehicle. When the temperature of the vehicle exterior space is equal to or lower than a predetermined reference temperature, the control device sets the duty ratio of the heating device in the second control mode candidate to a larger value as the temperature difference between the vehicle interior space and the vehicle exterior space decreases.

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