Anti-fog system

Abstract

Regarding the anti-fogging system, it improves visibility from the outside of the vehicle and reduces the visual and psychological burden on the driver. [Solution] The disclosed anti-fogging system comprises an air vent 5, a camera 8, and a control device 9. The air vent 5 has an openable and closable cover 7 and is located on the upper surface of the dashboard 4. The camera 8 is installed inside the vehicle and captures the reflection of the air vent 5 on the windshield 2. Based on the image captured by the camera 8, the control device 9 calculates the brightness difference between the bright and dark parts of the air vent 5 in the reflection, and if the brightness difference is greater than or equal to a predetermined value, it performs a closing control to close the air vent 5 with the cover 7.

Description

Technical Field

[0001] This invention relates to an anti-fogging system for a windshield.

Background Art

[0002] At the lower part of the front windshield (front windshield glass) of a vehicle, an anti-fogging system (defrosting system, demisting system) may be provided to ensure the visibility ahead of the vehicle. The anti-fogging system has a function of removing condensed water or frost adhering to the front windshield by blowing warm air or dry air onto the inner surface of the front windshield. The outlets for the warm air or dry air are arranged to extend in the vehicle width direction along the lower edge of the front windshield (see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The upper surface of the dashboard where the outlets are formed is likely to be brightly illuminated by external light incident from the front windshield. On the other hand, it is difficult for external light to enter the duct part inside the outlets. Therefore, when the dashboard is reflected in the front windshield on a sunny day at noon, the image of the upper surface of the dashboard with high brightness and the image of the outlets with low brightness overlap with the scenery outside the vehicle, which may make the driver feel annoyance in visibility and difficulty in grasping the situation. In other words, there is a problem that the visibility outside the vehicle decreases due to the brightness difference of the reflection around the outlets, increasing the visual and psychological burdens on the driver.

[0005] One of the objectives of this invention is to provide an anti-fogging system that addresses the aforementioned challenges, improves visibility from the outside of the vehicle, and reduces the visual and psychological burden on the driver. Beyond this objective, another objective of this invention is to achieve effects and benefits derived from the various configurations described in the "Modes for Carrying Out the Invention" section below, which cannot be obtained with conventional technologies. [Means for solving the problem]

[0006] The disclosed anti-fogging system can be implemented in the following embodiments (examples of application) and solves at least some of the above-mentioned problems. Each of the embodiments from Embodiment 2 onward is an additional embodiment that can be appropriately selected and each is an embodiment that can be omitted. None of the embodiments from Embodiment 2 onward disclose any embodiments or configurations that are essential to this case.

[0007] Embodiment 1. The anti-fogging system disclosed hereto performs defrost control to remove frost or condensation from the windshield of a vehicle. The anti-fogging system comprises an air vent, a camera, and a control device. The air vent has an openable and closable lid and is located on the top surface of the dashboard. The camera is located inside the vehicle and captures the reflection of the air vent on the windshield. The control device calculates the brightness difference between the bright and dark parts of the air vent in the reflection based on the image captured by the camera, and if the brightness difference is greater than or equal to a predetermined value, it performs closing control to close the air vent with the lid.

[0008] Embodiment 2. With respect to embodiments including Embodiment 1 described above, it is preferable that the closing control is performed when the defrost control is not performed. In other words, it is preferable that the closing control is not performed while the defrost control is being performed. Embodiment 3. With respect to embodiments including Embodiment 1 described above, it is preferable that the closing control is performed when the conditions for condensation on the windshield are not met. In other words, it is preferable that the closing control is not performed when the conditions for condensation on the windshield are met.

[0009] Embodiment 4. With respect to embodiments including Embodiment 1 described above, it is preferable that the outlet has movable fins for adjusting the direction of airflow, and that the movable fins also function as a lid. Embodiment 5. With respect to embodiments including Embodiment 1 described above, it is preferable that the surface material of the lid is the same material as the surface material of the upper surface of the dashboard. [Effects of the Invention]

[0010] According to the disclosed anti-fogging system, if the brightness difference of the reflection around the air vent exceeds a predetermined value, the brightness difference can be reduced by covering the air vent with a lid. This improves the visibility of the outside of the vehicle and reduces the visual and psychological burden on the driver. [Brief explanation of the drawing]

[0011] [Figure 1] This is a block diagram of a vehicle to which the anti-fogging system according to the embodiment is applied. [Figure 2] This diagram shows the reflection of the air vent when it is open. [Figure 3] (A) is a vertical cross-sectional view of the dashboard showing the air vents in the open position, and (B) is a vertical cross-sectional view of the dashboard showing the air vents in the open position. [Figure 4] This diagram shows the reflection of a closed air vent. [Figure 5] This is a flowchart showing the flow of the closure control. [Modes for carrying out the invention]

[0012] [1. Structure] Figure 1 is a block diagram of vehicle 1 to which the anti-fogging system according to the embodiment is applied. This anti-fogging system performs control to remove frost or condensation adhering to the surface of the windshield 2. Frost adhering to the outer surface of the windshield 2 can be removed by blowing warm air onto the inner surface of the windshield 2. Similarly, condensation adhering to the inner surface of the windshield 2 can be removed by blowing warm air or dry air onto the inner surface of the windshield 2.

[0013] Hereafter, the control that removes frost or condensation from the windshield 2 will simply be referred to as defrost control. The warm or dry air used in defrost control is generated by the blower 3 (air conditioning system, heating system) installed in the vehicle 1. This anti-fogging system is sometimes called a defroster or demister. Hereafter, the warm or dry air used in defrost control will be referred to as air conditioning air.

[0014] The anti-fogging system in this embodiment includes an air outlet 5, a camera 8, and a control device 9. The air outlet 5 is an opening that blows conditioned air toward the windshield 2. The air outlet 5 is located on the upper surface of the dashboard 4 of the vehicle 1. The air outlet 5 is positioned, for example, near the front end of the dashboard 4, extending in the vehicle width direction along the lower edge of the windshield 2.

[0015] A hollow duct 6 connects the air outlet 5 and the blower 3. In defrost control, the conditioned air generated by the blower 3 flows through the duct 6, is discharged from the air outlet 5, and is blown onto the inner surface of the windshield 2 located above the dashboard 4.

[0016] The blowing outlet 5 is provided with movable fins 7 for adjusting the direction of the flow of the air-conditioning air. The movable fins 7 are plate members having the function of a flow rectifying plate for adjusting the flow direction of the air-conditioning air so that the air-conditioning air discharged from the blowing outlet 5 is evenly supplied to the entire front glass 2. In this embodiment, a plurality of movable fins 7 are provided, and these movable fins 7 also serve as a lid capable of opening and closing the blowing outlet 5. Each movable fin 7 is pivotally supported, for example, with respect to the vehicle body (dashboard 4 and duct 6) of the vehicle 1 so as to be rotatable.

[0017] The skin material of the movable fin 7 is preferably set to be the same as the skin material on the upper surface of the dashboard 4. For example, the skin material of the movable fin 7 is made of the same material (same color, same texture) as the skin material on the upper surface of the dashboard 4. Thereby, in the reflection 20 described later, it becomes easy to make the upper surface of the dashboard 4 and the movable fin 7 have the same brightness.

[0018] The angle of the plate surface of the movable fin 7 with respect to the vehicle body is adjustable by an actuator (motor, piston, link mechanism, etc.) not shown. The operating state of the actuator and the angle of the plate surface of the movable fin 7 are controlled by the control device 9. By changing the angle of the plate surface of the movable fin 7, the blowing outlet 5 can be switched at least between an open state and a closed state.

[0019] The open state mentioned here means a state in which the air-conditioning air can be blown onto the inner surface of the front glass 2. The open state does not have to be a completely open state (a state where the effective cross-sectional area in the vicinity of the movable fin 7 is equal to the maximum cross-sectional area of the duct 6). Similarly, the closed state mentioned here means a state in which the flow path cross-sectional area is small compared to the open state. The closed state does not have to be a completely closed state (a state where the effective cross-sectional area in the vicinity of the movable fin 7 is zero). A preferable closed state is a state in which the inside of the duct 6 cannot be seen from the passenger compartment side.

[0020] The camera 8 is an imaging device that captures the reflection 20 (see FIG. 2) of the air outlet 5 on the windshield 2. The camera 8 is provided inside the vehicle cabin of the vehicle 1 and is arranged, for example, near the ceiling surface or near the headrest of the driver's seat. The camera 8 may capture a still image or may capture a moving image. The camera 8 may have a function of capturing only an image of the periphery of the dashboard 4 reflected on the windshield 2, or may have a function of also capturing the outside of the windshield 2 (a drive recorder function). The captured image of the camera 8 is input to the control device 9.

[0021] FIG. 2 is an example of a captured image when the camera 8 is used to capture the dashboard 4 and the lower part of the windshield 2 from inside the vehicle cabin. In this captured image, the reflection 20 when the open air outlet 5 is reflected on the windshield 2 and the external scenery 23 (road surface markings, road shoulders, sidewalk plantings, etc.) of the vehicle 1 visible through the windshield 2 are in a superimposed state. The reflection 20 of the air outlet 5 includes a bright part 21 with a relatively large amount of reflected light and a dark part 22 with a relatively small amount of reflected light.

[0022] The bright part 21 is a part corresponding to a place brightly illuminated by external light incident from the windshield 2. For example, the upper surface of the dashboard 4 and the reflection 20 of the upper part of the air outlet 5 above the movable fin 7 become the bright part 21. On the other hand, the dark part 22 is a part corresponding to a place that is difficult to be illuminated by external light incident from the windshield 2. For example, the reflection 20 of the lower part (the inner part of the duct 6) below the movable fin 7 becomes the dark part 22.

[0023] When the dashboard 4 is reflected on the windshield 2 on a sunny day at noon, the brightness difference (contrast) between the bright part 21 and the dark part 22 in the reflection 20 of the air outlet 5 may become large. The larger the brightness difference, the clearer and more prominent the reflection 20 itself becomes, resulting in a decrease in the visibility of the external scenery 23. Therefore, in order to reduce the above brightness difference, the anti-fogging system of the present embodiment performs a closing control to close the air outlet 5 with the movable fin 7.

[0024] Figures 3(A) and 3(B) are longitudinal cross-sectional views of the dashboard 4 showing the open and closed states of the air outlet 5. As shown in Figure 3(A), in the open state, the plate surface of the movable fin 7 is controlled to be almost vertical (aligned with the direction of airflow, vertical). Also, as shown in Figure 3(B), in the closed state, the plate surface of the movable fin 7 is controlled to be almost horizontal (blocking the airflow, horizontal). The dashed line in Figure 3(B) shows the outline of the movable fin 7 in the open state.

[0025] The control device 9 is a computer for performing closing control. The control device 9 incorporates a processor, main memory, and storage. The processing contents (program) of the control device 9 are stored in the storage, and these contents are read into the main memory as needed and executed by the processor. The control device 9 may be provided together with other electronic control devices that have other functions. For example, the functions of the control device 9 may be included in an air conditioning ECU or a vehicle body ECU.

[0026] The control device 9 calculates the brightness difference between the bright area 21 and the dark area 22 of the air outlet 5 in the reflection 20 based on the image captured by the camera 8. The control device 9 also performs closing control if the brightness difference is greater than or equal to a predetermined value. The brightness difference can be calculated using known methods. For example, the brightness of the bright area 21 and the dark area 22 can be quantified, and the difference between them can be calculated as the brightness difference.

[0027] When the closing control is implemented, the air vent 5 closes. Figure 4 is an example of an image captured by the camera 8, showing the reflection 20 when the closed air vent 5 is reflected on the windshield 2. When the air vent 5 is closed, the movable fin 7 reflects ambient light in the same way as the top surface of the dashboard 4. As a result, the area of ​​the dark area 22 shown in Figure 2 decreases, or the dark area 22 almost disappears, and the difference in brightness (contrast) between the bright area 21 and the dark area 22 in the reflection 20 becomes smaller. Therefore, visibility when looking at the outside world through the windshield 2 is improved, and the visual and psychological burden on the driver is reduced.

[0028] The following are examples of conditions for implementing closure control. Condition A is the only condition essential for closure control. Conditions B and C are additional conditions and can be omitted as appropriate. Conditions D to F are specific examples of conditions for determining whether condition C is successful or not. Condition A. The difference in brightness between the bright area 21 and the dark area 22 is greater than or equal to a predetermined value. Condition B. Defrost control is not performed. Condition C. Condensation conditions are not met. Condition D. The glass surface temperature exceeds the first temperature. Condition E. The difference between the glass surface temperature and the interior temperature is less than the second temperature. Condition F. The number of crew members is less than or equal to the prescribed number.

[0029] The first temperature in condition D may be a predetermined fixed value, or a variable value set according to the cabin temperature and humidity. In the latter case, for example, the dew point temperature may be calculated based on the cabin temperature and humidity, and the first temperature may be the value obtained by adding a predetermined temperature to that dew point temperature. Thus, condition D is met when the possibility of condensation occurring on the windshield 2 is low, and is not met when the possibility of condensation is increasing. Conditions E and F are conditions for a simplified assessment of the possibility of condensation.

[0030] When determining the above conditions, sensors may be provided on the vehicle 1. The vehicle 1 shown in Figure 1 is equipped with a glass temperature sensor 10 and a vehicle room temperature humidity sensor 11. The glass temperature sensor 10 is a sensor that detects the surface temperature (glass surface temperature) of the windshield 2. The vehicle room temperature humidity sensor 11 is a sensor that detects the temperature (cabin temperature) and humidity (cabin humidity) inside the vehicle. The information on the glass surface temperature, cabin temperature, and cabin humidity is transmitted to the control device 9. The control device 9 can perform the above condition determination based on this information.

[0031] [2. Flowchart] Figure 5 is a flowchart illustrating the flow of the closing control. This flowchart shows the processing flow when the conditions for implementing the closing control are "each of the above conditions A to C is met." The processing in this flowchart is repeatedly performed by the control device 9 at a predetermined cycle.

[0032] Step A1 determines whether or not defrost control is in progress. If the conditions in Step A1 are met, the processing for that cycle ends. If the conditions in Step A1 are not met (condition B is met), the process proceeds to Step A2. In step A2, the glass surface temperature, cabin temperature, and cabin humidity information detected by the glass temperature sensor 10 and the cabin cabin humidity sensor 11 are acquired by the control device 9.

[0033] In step A3, the dew point temperature of the vehicle interior is calculated based on the interior temperature and humidity. Additionally, a temperature obtained by adding a predetermined temperature (e.g., 5-10°C) to the dew point temperature is calculated as the condensation detection temperature. In step A4, it is determined whether or not the condensation conditions are met. For example, it is determined whether or not the glass surface temperature is below the condensation detection temperature. If the conditions in step A4 are met, the process proceeds to step A9, and the closing control is not performed. At this time, if the movable fin 7 (lid) is open, it remains open, and the process for that cycle ends. Conversely, if the movable fin 7 is closed, it opens, and the process for that cycle ends.

[0034] If the condition in step A4 is not met (i.e., condition C is met), the process proceeds to step A5. In step A5, the captured image from camera 8 is acquired by the control device 9. In step A6, based on the captured image, the difference in brightness between the bright areas 21 and the dark areas 22 in the reflection 20 of the air outlet 5 is calculated.

[0035] In step A7, it is determined whether the brightness difference is greater than or equal to a predetermined value. If the condition in step A7 is met (condition A is met), the process proceeds to step A8, and closing control is performed. At this time, if the movable fin 7 (lid) is closed, the closed state is maintained, and the process for that cycle ends. Conversely, if the movable fin 7 is open, the movable fin 7 is closed, and the process for that cycle ends.

[0036] If the conditions in step A7 are not met, the process proceeds to step A9, and the closing control is not performed. At this time, if the movable fin 7 is open, the open state is maintained, and the process for that cycle ends. Conversely, if the movable fin 7 is closed, the movable fin 7 is opened, and the process for that cycle ends.

[0037] [3. Effects] (1) The above-described anti-fogging system performs defrost control to remove frost or condensation from the windshield 2 of the vehicle 1. This anti-fogging system comprises an air vent 5, a camera 8, and a control device 9. The air vent 5 has an openable and closable cover (movable fin 7) and is located on the upper surface of the dashboard 4. The camera 8 is installed inside the vehicle and captures the reflection 20 of the air vent 5 on the windshield 2.

[0038] The control device 9 calculates the brightness difference between the bright area 21 and the dark area 22 of the air outlet 5 in the reflection 20 based on the image captured by the camera 8, and if the brightness difference is greater than or equal to a predetermined value, it performs a closing control to block the air outlet 5 with a cover (movable fin 7). According to the anti-fog system described above, if the brightness difference of the reflection 20 at the air outlet 5 exceeds a predetermined value, the brightness difference can be reduced by covering the air outlet 5 with a lid. This improves visibility when looking at the outside world through the windshield 2. Therefore, it can reduce the visual and psychological burden on the driver.

[0039] (2) The above closing control is performed when defrost control is not performed. This allows defrost control to be prioritized over closing control, ensuring that frost or condensation on the windshield 2 is reliably removed. Therefore, visibility of the outside world can be improved, further reducing the visual and psychological burden on the driver. In addition, if defrost control is not performed, closing control can be started immediately according to the difference in brightness, improving convenience while reducing the visual and psychological burden on the driver.

[0040] (3) The above closing control is performed when the conditions for condensation on the windshield 2 are not met. This allows the closing control to be suspended when condensation is actually occurring or when conditions are likely to occur. Therefore, for example, if defrost control is started afterward, the air conditioning can be immediately blown onto the windshield 2, improving convenience. Also, if the conditions for condensation are not met, the closing control can be started immediately according to the difference in brightness, improving convenience while reducing the visual and psychological burden on the driver.

[0041] (4) The above-mentioned air outlet 5 has movable fins 7 for adjusting the direction of the airflow. These movable fins 7 also function as a cover. In this way, by utilizing the existing structure, the brightness difference of the reflections 20 can be easily reduced. In addition, compared to the case in which a separate cover is provided in addition to the movable fins 7, the structure of the air outlet 5 is simplified, so the aesthetic appearance of the top surface of the dashboard 4 can be improved while suppressing an increase in cost.

[0042] (5) Preferably, the surface material of the lid is the same material as the surface material of the top surface of the dashboard 4. This makes it easy to make the top surface of the dashboard 4 and the lid (movable fin 7) have roughly the same brightness in the reflection 20. Therefore, the effect of improving visibility can be enhanced, and the visual and psychological burden on the driver can be reduced more reliably.

[0043] [4. Others] In the anti-fog system described above, the movable fins 7 also function as a lid, but a separate lid member that can open and close the outlet 5 may be provided in addition to the movable fins 7. At the very least, by closing the outlet 5 with the lid member when the brightness difference exceeds a predetermined value, an anti-fog system similar to the above embodiment can be realized, and the same effects can be obtained. [Industrial applicability]

[0044] This technology is applicable to the manufacturing industry of vehicle anti-fogging systems and to the manufacturing industry of vehicles to which anti-fogging systems are applied. [Explanation of symbols]

[0045] 1 vehicle 2 Windshield 3. Blower 4 Dashboard 5. Air outlet 6 ducts 7. Movable fins (cover) 8 cameras 9 Control device 10 Glass temperature sensor 11. Car room temperature and humidity sensor 20 Reflections 21 Akabe 22 Dark part 23 Scenery

Claims

1. An anti-fogging system that performs defrost control to remove frost or condensation from the windshield of a vehicle, It has an openable and closable lid and is located on the top surface of the dashboard. A camera is installed inside the vehicle to capture the reflection of the air vents on the windshield, A control device that calculates the brightness difference between the bright and dark parts of the air outlet in the reflection based on the image captured by the camera, and performs a closing control to block the air outlet with the cover if the brightness difference is greater than or equal to a predetermined value. An anti-fog system characterized by having the following features.

2. The aforementioned closing control is performed when the aforementioned defrost control is not performed. The anti-fog system according to claim 1, characterized in that...

3. The aforementioned closing control is performed when the conditions for condensation on the windshield are not met. The anti-fog system according to claim 1, characterized in that...

4. The aforementioned outlet has movable fins for adjusting the direction of airflow, The movable fin also serves the function of the lid. The anti-fog system according to claim 1, characterized in that...

5. The surface material of the lid is the same material as the surface material of the top surface of the dashboard. The anti-fog system according to claim 1, characterized in that...

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