Anti-fogging system and control method

Abstract

To provide a defogging system which can properly operate a defogging device for such a situation that fogging easily occurs on a glass of a vehicle.SOLUTION: A defogging system according to the present disclosure comprises: a defogging device which prevents fogging of a glass of a vehicle; and a control device which controls the defogging device. The control device is configured to execute: processing of operating the defogging device when a prescribed condition is satisfied; processing of acquiring information about at least a conversation state including whether or not a passenger of the vehicle is having a conversation; and processing of changing the prescribed condition on the basis of the information about the conversation state.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present disclosure relates to control of an anti-fogging device that prevents fogging of vehicle windows. [Background technology]

[0002] Patent Document 1 discloses that when it is determined that the time that has elapsed since the ignition switch was turned on is equal to or longer than a predetermined time, a compressor that causes a defroster to function is operated. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-061245 A Summary of the Invention [Problem to be solved by the invention]

[0004] Fogging on the windshield or rear window of a vehicle reduces the visibility in front of and behind the vehicle when viewed from inside the vehicle. On the other hand, in autonomous driving systems and driving assistance systems, the information detected by cameras installed inside the vehicle through the windshield or rear window is important information for recognizing the environment around the vehicle. For this reason, in order to ensure sufficient performance of autonomous driving and driving assistance systems, it is desirable to keep the vehicle's windows clear.

[0005] However, the anti-fogging device is generally composed of a heater and an air conditioning device, and consumes a lot of power. For this reason, it is not desirable to operate the anti-fogging device all the time from the viewpoint of fuel efficiency and environmental performance. Therefore, in an autonomous driving system or a driving assistance system, it is required to operate the anti-fogging device mainly in a situation where fogging is likely to occur.

[0006] Incidentally, the occurrence of fogging is greatly influenced by the humidity inside the vehicle. Therefore, it can be considered that fogging is likely to occur when the humidity inside the vehicle is rising. However, it is hardly considered that humidity measurement is required for the functions of automatic driving and driving assistance, and it is not desirable from the viewpoint of cost and design to provide a sufficient number of high-precision hygrometers according to the structure of the vehicle interior.

[0007] Patent Document 1 discloses that the humidity rise inside the vehicle is detected by focusing on the time elapsed since the ignition switch was turned on. However, depending on the situation of the vehicle occupants, even if the time elapsed since the ignition switch was turned on is more than a predetermined time, the situation may not be conducive to fogging. As a result, there is a risk that the anti-fogging device will operate unnecessarily.

[0008] In view of the above-mentioned problems, one object of the present disclosure is to provide a technique that enables an anti-fogging device to operate appropriately in conditions where fogging is likely to occur without a hygrometer. [Means for solving the problem]

[0009] A first aspect of the present disclosure relates to an anti-fogging system.

[0010] The anti-fogging system according to a first aspect includes an anti-fogging device that prevents fogging of vehicle windows, and a control device that controls the anti-fogging device, and the control device is configured to execute the following processes: operating the anti-fogging device when specified conditions are satisfied; acquiring information regarding a conversation situation, including at least whether or not an occupant of the vehicle is talking; and changing the specified conditions based on the information regarding the conversation situation.

[0011] A second aspect of the present disclosure relates to a control method for controlling, by a computer, an anti-fogging device that prevents fogging of vehicle windows.

[0012] The control method according to the second aspect is characterized in that it includes operating an anti-fogging device when predetermined conditions are satisfied, acquiring information regarding a conversation situation of vehicle occupants, including at least whether or not they are talking, and changing the predetermined conditions based on the information regarding the conversation situation. Effect of the Invention

[0013] According to the present disclosure, the predetermined conditions for operating the anti-fogging device are changed based on information on the conversation situation, including at least whether or not a conversation is taking place. This makes it possible to make the anti-fogging device 400 more or less operable depending on the conversation situation. As a result, it is possible to accurately detect an increase in humidity inside the vehicle, and to operate the anti-fogging device appropriately in a situation where fogging is likely to occur. [Brief description of the drawings]

[0014] [Figure 1] 1 is a block diagram showing a configuration of an anti-fogging system according to an embodiment of the present invention. [Diagram 2] 1 is a block diagram showing an example of the configuration of a vehicle to which an anti-fogging system according to an embodiment of the present invention is applied. [Diagram 3] FIG. 2 is a block diagram showing a configuration of a control device according to the present embodiment. [Figure 4] 4 is a flowchart showing a process executed by a control device according to the present embodiment. [Diagram 5] 1 is a diagram showing an example of an anti-fogging system according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, the present embodiment will be described with reference to the drawings.

[0016] 1. Configuration FIG. 1 is a block diagram showing the configuration of an anti-fogging system 10 according to this embodiment. The anti-fogging system 10 detects a situation in which fogging is likely to occur on the glass of a vehicle, and provides an anti-fogging function by operating an anti-fogging device 400. The anti-fogging system 10 includes a control device 100, sensors 200, a communication device 300, and an anti-fogging device 400. Here, the control device 100 is connected to the sensors 200, the communication device 300, and the anti-fogging device 400 so as to be able to transmit information to each other. For example, the control device 100 is connected to these devices via an in-vehicle network configured by a CAN (Control Area Network) or the like.

[0017] The sensors 200 are provided in a vehicle and detect the vehicle's running state and the environment inside and outside the vehicle. The sensors 200 include an in-vehicle monitoring camera 210, an audio sensor 220, and a surroundings monitoring camera 230. The in-vehicle monitoring camera 210, the audio sensor 220, and the surroundings monitoring camera 230 will be described with reference to Fig. 2.

[0018] FIG. 2 is a conceptual diagram showing an example of the configuration of a vehicle 1 to which the anti-fogging system 10 is applied, with respect to an interior monitoring camera 210, an audio sensor 220, and a surrounding monitoring camera 230. As shown in FIG.

[0019] The interior monitoring camera 210 is a camera that captures the situation inside the vehicle 1. In particular, the interior monitoring camera 210 is arranged so as to capture the situation of the passenger 2 of the vehicle 1 (the passenger 2 may be one person). The detection information output by the interior monitoring camera 210 may be captured video data, or may be information obtained by image recognition of the captured video data. In the latter case, the interior monitoring camera 210 is configured to output information on the conversation situation of the passenger 2 of the vehicle 1. Here, the information on the conversation situation includes at least information on whether the passenger 2 of the vehicle 1 is talking or not. For example, the interior monitoring camera 210 detects whether the passenger 2 of the vehicle 1 is talking or not by acquiring the change in facial expression, mouth movement, and mouth opening amount of the passenger 2 of the vehicle 1 shown in the captured video data by image recognition. Other examples of the information on the conversation situation output by the interior monitoring camera 210 include the number of passengers 2 who are talking and the positions of the passengers 2 who are talking. 2 shows an example 211 of video data captured by the in-vehicle monitoring camera 210. In this case, the in-vehicle monitoring camera 210 outputs, for example, detection information indicating that two passengers 2 are having a conversation.

[0020] The in-vehicle monitoring camera 210 may be a driver monitor provided for an automatic driving or driving assistance function, or a drive recorder that captures images inside the vehicle. However, the camera may be a camera provided to configure the anti-fogging system 10.

[0021] The voice sensor 220 is a sensor that detects voice inside the vehicle 1. The detection information output by the voice sensor 220 is typically voice data obtained by encoding the detected voice.

[0022] The voice sensor 220 may be an audio device having a microphone function or a hands-free system having a voice recognition function. However, it may be a microphone provided for configuring the anti-fogging system 10.

[0023] The periphery monitoring camera 230 is a camera that captures an image of the situation around the vehicle 1. Typically, the periphery monitoring camera 230 captures an image of the situation around the vehicle 1 through the windshield or rear window. In Fig. 2, a camera that captures an image of the situation ahead of the vehicle 1 through the windshield 3 is shown as the periphery monitoring camera 230. The detection information output by the periphery monitoring camera 230 may be captured video data, or may be information obtained by image recognition of the captured video data.

[0024] The periphery monitoring camera 230 may be a camera provided for an automatic driving or driving assistance function, or may be a camera provided for configuring the anti-fogging system 10.

[0025] Thus, the anti-fogging system 10 includes the sensors 200. Detection information output by the sensors 200 is transmitted to the control device 100.

[0026] Referring again to FIG. 1, the communication device 300 is a device that communicates with devices external to the vehicle 1 and transmits and receives information. For example, the communication device 300 connects to the Internet via a mobile communication network and communicates with a server on the Internet. Examples of information received by the communication device 300 include weather information around the vehicle 1, meteorological information, map information, road traffic information, and the like. The information received by the communication device 300 is transmitted to the control device 100.

[0027] The control device 100 executes processes related to the anti-fogging function based on the acquired information. In particular, the control device 100 is configured to execute an operation determination process P101 and a control process P102 as processes related to the anti-fogging function.

[0028] The operation determination process P101 is a process for determining whether or not to operate the defrosting device 400. In particular, the control device 100 determines to operate the defrosting device 400 when a predetermined condition is satisfied in the operation determination process P101. Here, the predetermined condition is typically that a specific state value for the vehicle 1 exceeds a predetermined threshold. The specific state value is generally a value related to the state of fogging occurring on the glass of the vehicle 1. For example, the specific state value may be a numerical value (e.g., 0%-100%) representing the degree of fogging of the windshield 3. In this case, for example, the control device 100 determines that the predetermined condition is satisfied in the operation determination process P101 when the degree of fogging of the windshield 3 exceeds 20%. Note that the degree of fogging of the windshield 3 can be obtained, for example, by image recognition of video data acquired from the surrounding monitoring camera 230.

[0029] Other specific state values ​​for the vehicle 1 include the temperature difference between the inside and outside of the vehicle 1, the time elapsed since the defrosting device 400 was stopped, etc. In particular, the specific state value may be a value that is the subject of threshold determination adopted in a conventional defrosting system that performs threshold control of the defrosting device. The predetermined condition may be given as a combination of multiple state values. For example, the predetermined condition may be given as the degree of fogging on the windshield 3 exceeding 20% ​​and / or the temperature difference between the inside and outside of the vehicle 1 exceeding 5 degrees. The threshold value may also have a hysteresis width.

[0030] In this way, the predetermined condition can typically be that a specific state value for the vehicle 1 exceeds a specific threshold value. In the following description, the specific state value for the vehicle 1 will be referred to as a "cloudy state value."

[0031] The control device 100 is further configured to obtain information relating to a conversation situation regarding the passenger 2 of the vehicle 1 in the action determination process P101, and to change the predetermined condition based on the information relating to the conversation situation.

[0032] Here, the information on the conversation situation includes at least information on whether the passengers 2 of the vehicle 1 are talking or not. Other examples of the information on the conversation situation include the number of passengers 2 who are talking, the duration of the conversation, the volume of the conversation, and the like. The control device 100 acquires the information on the conversation situation, for example, by image recognition of video data acquired from the in-vehicle monitoring camera 210 or by analysis of audio data acquired from the audio sensor 220. Alternatively, the control device 100 may be configured to acquire the information on the conversation situation as detection information of the sensors 200. Furthermore, the change of the predetermined condition is typically a change of a threshold value related to the fogging state value. Changing the predetermined condition makes it easier or harder for the defrosting device 400 to operate.

[0033] The inventors of the present disclosure have found that an increase in humidity inside the vehicle 1 is highly dependent on the conversation status of the passengers 2 of the vehicle 1. In particular, the humidity inside the vehicle differs significantly between when the passengers 2 are talking and when they are not talking. According to this embodiment, by changing a predetermined condition based on information on the conversation status including at least whether or not the passengers are talking, it is possible to make the anti-fogging device 400 more or less likely to operate depending on the conversation status. This makes it possible to accurately detect an increase in humidity inside the vehicle, and to operate the anti-fogging device 400 appropriately in a situation where fogging is likely to occur.

[0034] As a suitable example, the control device 100 changes the predetermined condition in the action determination process P101 based on information relating to the conversation situation as follows.

[0035] First, the control device 100 estimates the exhaled air volume of the passenger 2 of the vehicle 1 based on information related to the conversation situation. For example, the control device 100 can estimate the exhaled air volume per unit time (e.g., one minute) from a value obtained by numerically integrating the volume of the conversation over the duration of the conversation and correcting the value by the number of passengers 2 who are talking. In this case, estimating the exhaled air volume can also be said to be calculating the conversation volume.

[0036] The control device 100 then changes the predetermined condition so that the greater the estimated amount of exhaled air, the easier it is for the anti-fogging device 400 to operate. For example, the greater the estimated amount of exhaled air, the smaller the threshold value related to the fogging state value is set by the control device 100.

[0037] The amount of breath of the passenger 2 of the vehicle 1 directly affects the humidity inside the vehicle. Therefore, the greater the amount of breath estimated based on the information on the conversation situation, the easier it is to operate the defroster 400, thereby enabling more accurate detection of an increase in humidity inside the vehicle and operation of the defroster 400 at an appropriate time.

[0038] The control device 100 may be further configured to acquire weather information around the vehicle 1 and change the predetermined condition based on the weather information in the operation determination process P101. For example, when the weather around the vehicle 1 is rainy, the control device 100 further reduces the threshold value related to the cloudy state value.

[0039] The control device 100 can obtain weather information around the vehicle 1 by, for example, image recognition of video data acquired from the surroundings monitoring camera 230. Alternatively, the control device 100 may be configured to obtain weather information from the communication device 300.

[0040] The weather around the vehicle 1 serves as an index for judging the humidity inside the vehicle when the passengers 2 are not talking. For example, it is known that the humidity inside the vehicle is higher when it is raining or snowing around the vehicle 1 than when it is sunny. For this reason, even if the conversation situation of the passengers 2 is the same, it is considered that the humidity inside the vehicle will be somewhat different when the weather around the vehicle 1 is different. Therefore, by changing the predetermined conditions based on the weather information, it is possible to more accurately detect an increase in humidity inside the vehicle and to operate the defroster 400 at an appropriate time.

[0041] The control process P102 is a process for generating a control signal for the defrosting device 400 according to the processing result of the operation determination process P101. When it is determined in the operation determination process P101 that the defrosting device 400 is not to be operated, the control device 100 generates a control signal for stopping the defrosting device 400 in the control process P102. On the other hand, when it is determined in the operation determination process P101 that the defrosting device 400 is to be operated, the control device 100 generates a control signal for operating the defrosting device 400 in the control process P102. For example, when the defrosting device 400 is configured as a heater that generates heat from a heating element such as an electric heating wire, the control device 100 generates a control signal indicating the heat amount of the heating element in the control process P102. Also, for example, when the defrosting device 400 is configured as an air conditioning facility, the control device 100 generates a control signal for controlling the inside air / outside air of the air conditioning facility in the control process P102.

[0042] Here, the control device 100 may be configured to generate a control signal in the control process P102 based on the detection information acquired from the sensors 200 and the processing result of the motion determination process P101. For example, the control device 100 generates a control signal indicating a larger calorific value as the amount of exhaled air estimated in the motion determination process P101 increases.

[0043] The defrosting device 400 operates according to a control signal output by the control device 100. The defrosting device 400 can also be called a defroster or a defogger. The defrosting device 400 is typically configured with a heater or air conditioning equipment and is intended for the windshield 3 or rear window of the vehicle 1. However, the defrosting device 400 may adopt a suitable form depending on the environment in which the defrosting system 10 is applied. The defrosting function of the defrosting system 10 is realized by the defrosting device 400 operating according to the control signal.

[0044] As described above, the anti-fogging system 10 according to this embodiment is configured.

[0045] Next, the configuration of the control device 100 according to this embodiment will be described with reference to Fig. 3. Fig. 3 is a block diagram showing a preferred example of the control device 100.

[0046] The control device 100 is a computer including a storage device 110 and a processor 120. The storage device 110 can be configured with a recording medium such as a ROM, a RAM, a HDD, or an SSD. The processor 120 can be configured with a CPU or the like including an arithmetic unit and a register. The control device 100 is configured with, for example, one or more ECUs (Electronic Control Units).

[0047] The storage device 110 is coupled to the processor 120 and stores a number of instructions 112 executable by the processor 120, as well as various data 113 required for the execution of the process.

[0048] The instructions 112 are provided by a computer program 111. The instructions 112 are configured to cause the processor 120 to execute processes related to the anti-fogging function. That is, the processor 120 operates in accordance with the instructions 112 to execute an operation determination process P101 and a control process P102. The data 113 includes information acquired by the control device 100, parameter information of the computer program 111, and the like.

[0049] As described above, the control device 100 according to this embodiment can be configured.

[0050] 2. Processing The process relating to the anti-fogging function executed by the control device 100 will be described below.

[0051] Fig. 4 is a flowchart showing an example of processing executed by the control device 100, more specifically, processing executed by the processor 120. The processing according to the flowchart shown in Fig. 4 starts, for example, when the ignition switch of the vehicle 1 is turned on, and is repeatedly executed at predetermined intervals.

[0052] In step S100, the control device 100 acquires information related to the conversation state of the passenger 2 of the vehicle 1 and weather information.

[0053] Next, in step S200, the control device 100 estimates the amount of breath of the passenger 2 of the vehicle 1 based on the information related to the conversation situation.

[0054] Next, in step S300, the control device 100 changes the threshold value related to the fogging state value of the vehicle 1 according to the weather information acquired in step S100 or the exhaled air volume estimated in step S200. In particular, the control device 100 reduces the threshold value as the estimated exhaled air volume increases so that the anti-fogging device 400 can operate more easily.

[0055] Next, in step S400, the control device 100 calculates a fogging state value based on the acquired information.

[0056] Next, in step S500, the control device 100 determines whether the fogging value calculated in step S400 exceeds a threshold value.

[0057] If the fogging state value exceeds the threshold value (step S500; Yes), the control device 100 determines to operate the anti-fogging device 400 and controls the anti-fogging device 400 (step S600). If the fogging state value does not exceed the threshold value (step S500; No), the control device 100 stops the anti-fogging device 400 (step S700).

[0058] As described above, the control device 100 executes the processes related to the anti-fogging function. Furthermore, by the control device 100 executing the processes in this manner, a control method in which the anti-fogging device 400 is controlled by a computer is realized.

[0059] 3. Working Example An example of the anti-fogging system 10 according to this embodiment will be described below with reference to FIG.

[0060] Fig. 5 shows, as an example, a graph showing the time change of the estimated exhaled air volume and a graph showing the time change of the fogging value. In particular, the graph showing the time change of the fogging value shows a case where the anti-fogging system 10 according to this embodiment is applied (with threshold change, solid line) and a case where it is not applied (without threshold change, dashed line). Here, the horizontal axis showing the passage of time is the same in both graphs. Fig. 5 shows a case where the control device 100 changes the threshold related to the fogging value between a first threshold and a second threshold according to the estimated exhaled air volume.

[0061] In the case where the anti-fogging system 10 according to the present embodiment is not applied, the anti-fogging device 400 does not operate until the fogging state value exceeds the first threshold value. Therefore, as shown in FIG. 5, the operation of the anti-fogging device 400 may be delayed with respect to the increase in humidity inside the vehicle, and the fogging state value may increase excessively. As a result, the performance of automatic driving and driving assistance may not be sufficiently ensured. In addition, if the threshold value related to the fogging state value is set to the second threshold value, the anti-fogging device 400 may operate unnecessarily even when an increase in humidity inside the vehicle is not expected, and fuel efficiency and environmental performance may be reduced.

[0062] On the other hand, when the anti-fogging system 10 according to the present embodiment is applied, at time t1, the control device 100 lowers the threshold value related to the fogging state value from the first threshold value to the second threshold value because the estimated exhaled air volume is large. As a result, the fogging state value exceeds the threshold value, and the control device 100 starts controlling the anti-fogging device 400. As a result, even if the exhaled air volume increases further after time t1 and the humidity inside the vehicle is expected to increase, the anti-fogging device 400 can be operated appropriately without increasing the fogging state value.

[0063] Then, at time t3, because the estimated amount of exhaled air is small, the control device 100 increases the threshold value related to the fogging state value from the first threshold value to the second threshold value. As a result, because the fogging state value becomes smaller than the threshold value, the control device 100 stops the defrosting device 400. This makes it possible to prevent the defrosting device 400 from operating unnecessarily after time t3 when the amount of exhaled air is small and there is no concern about an increase in humidity in the vehicle.

[0064] Thus, according to this embodiment, the antifogging device 400 can be operated appropriately in a situation where fogging is likely to occur without a hygrometer. The antifogging system 10 according to this embodiment can also be applied by utilizing the configuration of a conventional automatic driving system or driving assistance system. In the above example, the threshold value related to the fogging state value is changed between the first threshold value and the second threshold value, but other modes of changing the threshold value can also be adopted. For example, the control device 100 may be configured to change the threshold value in more stages according to the exhalation volume, or may be configured to change the threshold value according to a map that gives a threshold value for the exhalation volume. [Explanation of symbols]

[0065] 1 vehicle, 2 passenger, 3 windshield, 10 anti-fogging system, 100 control device, 210 in-vehicle surveillance camera, 220 audio sensor, 230 surrounding surveillance camera, 300 communication device, 400 anti-fogging device

Claims

1. An anti-fogging device for preventing fogging of vehicle windows; A control device for controlling the anti-fogging device; Equipped with The control device includes: activating the anti-fogging device when a predetermined condition is met; obtaining information about a conversation situation of the vehicle occupants, the information including at least whether or not the occupants are talking; A process of changing the predetermined condition based on information about the conversation situation; It is configured to run An anti-fogging system characterized by:

2. 2. The anti-fogging system of claim 1, The process of changing the predetermined condition includes: estimating an exhaled air volume of the occupant based on information about the conversation situation; Changing the predetermined condition so that the anti-fogging device becomes more likely to operate as the amount of exhaled air increases; Includes An anti-fogging system characterized by:

3. 3. The anti-fogging system of claim 2, the predetermined condition being one or more particular state values ​​for the vehicle exceeding a predetermined threshold; The information about the conversation situation further includes information about the number of passengers who are talking, the duration of the conversation, and the volume of the conversation; Changing the predetermined condition is changing the threshold value. An anti-fogging system characterized by:

4. An anti-fogging system according to any one of claims 1 to 3, The control device includes: A process of acquiring weather information around the vehicle; A process of changing the predetermined condition based on the weather information; is configured to further An anti-fogging system characterized by:

5. A control method for controlling an anti-fogging device that prevents fogging of vehicle windows by a computer, comprising: activating the defogging device when a predetermined condition is met; and obtaining information regarding a conversation status of an occupant of the vehicle, the information including at least whether or not the occupant is talking; modifying the predetermined condition based on information about the conversation situation; A control method comprising:

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