Anti-fog system and method for vehicle

Abstract

The invention relates to an anti-fog system and method for a vehicle. The anti-fog system for the vehicle comprises a position detection device, a vehicle speed detection device, a humidity detection device, a temperature detection device, an illuminance detection device and a main control device. The main control device is in communication connection with the position detection device, the vehicle speed detection device, the humidity detection device, the temperature detection device and the illuminance detection device, and is configured to obtain the driving position of the vehicle, the driving speed of the vehicle, and the temperature, humidity and illuminance of the external environment of the vehicle; based on the driving position of the vehicle, the driving speed of the vehicle and the temperature and humidity of the external environment of the vehicle, whether a fogging risk exists when the vehicle is driven out of the tunnel exit or not is determined before the vehicle is driven out of the tunnel exit; and when it is determined that the fogging risk exists when the vehicle is driven out of the tunnel exit, the air conditioner control device is further made to preheat the front windshield in advance based on the illuminance of the external environment of the vehicle.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle control, and more particularly, to an anti-fog system and method for a vehicle. Background Art

[0002] With the development of highway traffic, more and more extra-long (e.g., with a length of over 10 kilometers) highway tunnels are put into operation, and most of the extra-long highway tunnels are distributed in mountainous areas. For those extra-long highway tunnels, the temperature inside the tunnel is much lower than that outside, and it takes a long time to drive out of the tunnel, which makes the temperature of the front windshield relatively low when driving out of the extra-long tunnel. At this time, if the external air humidity is high, the outer surface of the front windshield may quickly fog up, which is very dangerous in the case of high-speed driving.

[0003] The currently installed automatic defogging system (ADS) on vehicles is only used to solve the problem of fogging on the inner surface of the front windshield, and there is currently no effective solution for the rapid fogging on the outer surface of the front windshield.

[0004] The above statement of the background art is only for the convenience of in-depth understanding of the technical solution of the present invention (such as the technical means used, the technical problems solved, and the technical effects produced, etc.), and should not be regarded as an admission or any form of implication that this information constitutes the prior art already known to those skilled in the art. Summary of the Invention

[0005] The purpose of the present invention is to solve the problem of rapid fogging on the outer surface of the front windshield when driving in a highway tunnel. By using GPS information, map data, weather data, vehicle speed, and the external temperature of the tunnel, the fogging risk is predicted before the vehicle drives out of the tunnel exit, and then the air-conditioning system is used to preheat the front windshield in advance to avoid the problem of rapid fogging when the vehicle drives out of the tunnel exit.

[0006] According to an embodiment of the present invention, an anti-fogging system for a vehicle is provided, including: a position detection device configured to detect the driving position of the vehicle; a vehicle speed detection device configured to detect the driving speed of the vehicle; a humidity detection device configured to detect the humidity of the external environment of the vehicle; a temperature detection device configured to detect the temperature of the external environment of the vehicle; an illuminance detection device configured to detect the illuminance of the external environment of the vehicle; a main control device communicatively connected to the position detection device, the vehicle speed detection device, the humidity detection device, the temperature detection device, and the illuminance detection device, and configured to: obtain the driving position of the vehicle, the driving speed of the vehicle, the temperature, humidity, and illuminance of the external environment of the vehicle; based on the driving position of the vehicle, the driving speed of the vehicle, the temperature and humidity of the external environment of the vehicle, determine whether there is a risk of fogging when the vehicle exits the tunnel exit before the vehicle exits the tunnel exit; when it is determined that there is a risk of fogging when the vehicle exits the tunnel exit, further preheat the front windshield by the air-conditioning control device based on the illuminance of the external environment of the vehicle.

[0007] Preferably, the main control device is further configured to: when the vehicle travels to a first predetermined distance from the tunnel entrance, obtain the first temperature, the first humidity, and the first illuminance of the external environment of the vehicle; after the vehicle enters the tunnel entrance, obtain the second temperature of the external environment of the vehicle; calculate the temperature difference between the first temperature and the second temperature; compare the calculated temperature difference with a preset temperature difference; when the calculated temperature difference is greater than the preset temperature difference, determine that there is a risk of fogging when the vehicle exits the tunnel exit; the preset temperature difference is determined based on the first humidity.

[0008] Preferably, the main control device is further configured to: in the case where it is determined that there is a risk of fogging when the vehicle exits the tunnel exit, determine the allowable driving time of the vehicle based on the calculated temperature difference, the first humidity, and the first illuminance; compare the driving time after the vehicle enters the tunnel entrance with the allowable driving time of the vehicle; when the driving time after the vehicle enters the tunnel entrance is greater than the allowable driving time of the vehicle, compare the calculated remaining driving distance with a preset remaining distance; when the calculated remaining driving distance is less than the preset remaining distance, determine that it is necessary to preheat the front windshield by the air-conditioning control device in advance.

[0009] Preferably, determining the allowable driving time of the vehicle includes: determining the basic driving time of the vehicle through a mapping table of the first humidity and the basic driving time of the vehicle; determining the adjusted driving time of the vehicle through a mapping table of the first illuminance and the adjusted driving time of the vehicle; summing the basic driving time of the vehicle and the adjusted driving time of the vehicle to obtain the allowable driving time of the vehicle.

[0010] Preferably, the main control device is further configured to: when the driving time after the vehicle enters the tunnel entrance is less than the allowable driving time of the vehicle or when the calculated remaining driving distance is greater than the preset remaining distance, determine that it is not necessary to preheat the front windshield by the air-conditioning control device in advance.

[0011] Preferably, the main control device is further configured to: in the case of determining that it is necessary to preheat the front windshield by the air-conditioning control device in advance, based on the mapping table of the remaining driving distance and the preset target temperature and the preset blower gear, determine the preset target temperature and the preset blower gear according to the remaining driving distance, and make the air-conditioning control device work according to the preset target temperature and the preset blower gear.

[0012] Preferably, the main control device is further configured to: when it is determined that the vehicle has driven out of the tunnel exit by a second predetermined distance, make the air-conditioning control device resume its normal working state.

[0013] Preferably, the anti-fog system for a vehicle further includes a display device, which is communicably connected to the main control device and is configured to display a prompt message to the driver when it is determined that there is a risk of fogging.

[0014] Preferably, the communicable connection includes a connection by means of wired communication; the means of wired communication includes Controller Area Network, Universal Serial Bus, High-Definition Multimedia Interface, and Digital Video Interface.

[0015] According to an embodiment of the present invention, there is provided an anti-fog method for a vehicle, which includes: obtaining the driving position, driving speed, humidity, temperature, and illuminance of the vehicle external environment of the vehicle; based on the driving position, driving speed, temperature, and humidity of the vehicle external environment of the vehicle, determining whether there is a risk of fogging when the vehicle drives out of the tunnel exit before the vehicle drives out of the tunnel exit; when it is determined that there is a risk of fogging when the vehicle drives out of the tunnel exit, further preheating the front windshield by the air-conditioning control device based on the illuminance of the vehicle external environment.

[0016] Preferably, the anti-fog method for a vehicle further includes: when the vehicle travels to a first predetermined distance from the tunnel entrance, obtaining the first temperature, first humidity, and first illuminance of the vehicle external environment; after the vehicle enters the tunnel entrance, obtaining the second temperature of the vehicle external environment; calculating the temperature difference between the first temperature and the second temperature; comparing the calculated temperature difference with a preset temperature difference; when the calculated temperature difference is greater than the preset temperature difference, determining that there is a risk of fogging when the vehicle drives out of the tunnel exit; wherein, the preset temperature difference is determined based on the first humidity.

[0017] Preferably, when it is determined that there is a risk of fogging when the vehicle exits the tunnel exit, it includes: determining the allowable driving time of the vehicle based on the calculated temperature difference, the first humidity, and the first illuminance; comparing the driving time after the vehicle enters the tunnel entrance with the allowable driving time of the vehicle; when the driving time after the vehicle enters the tunnel entrance is greater than the allowable driving time of the vehicle, comparing the calculated remaining driving distance with the preset remaining distance; when the calculated remaining driving distance is less than the preset remaining distance, it is determined that the air-conditioning control device needs to preheat the front windshield in advance.

[0018] Preferably, determining the allowable driving time of the vehicle includes: determining the basic driving time of the vehicle through the mapping table of the first humidity and the basic driving time of the vehicle; determining the adjusted driving time of the vehicle through the mapping table of the first illuminance and the adjusted driving time of the vehicle; summing the basic driving time of the vehicle and the adjusted driving time of the vehicle to obtain the allowable driving time of the vehicle.

[0019] Preferably, when the driving time after the vehicle enters the tunnel entrance is less than the allowable driving time of the vehicle or when the calculated remaining driving distance is greater than the preset remaining distance, it is determined that there is no need for the air-conditioning control device to preheat the front windshield in advance.

[0020] Preferably, when it is determined that the air-conditioning control device needs to preheat the front windshield in advance, based on the mapping table of the remaining driving distance and the preset target temperature and the preset blower gear, determine the preset target temperature and the preset blower gear according to the remaining driving distance, and make the air-conditioning control device work according to the preset target temperature and the preset blower gear.

[0021] Preferably, when it is determined that the vehicle has traveled a second predetermined distance from the tunnel exit, the air-conditioning control device is restored to its normal working state.

[0022] Preferably, the anti-fog method for a vehicle further includes: when it is determined that there is a risk of fogging, displaying a prompt message to the driver.

[0023] The present invention adopts the above technical solutions, and has the following beneficial effects:

[0024] According to the embodiments of the present invention, it is possible to predict whether there is a risk of fogging when the vehicle exits the tunnel exit by using the driving position of the vehicle, the driving speed of the vehicle, the temperature and humidity of the vehicle's external environment. If it is predicted that there is a risk of fogging when the vehicle exits the tunnel exit, then further considering the illuminance of the vehicle, the air-conditioning control device is used to preheat the front windshield in advance to avoid the problem of rapid fogging when the vehicle exits the tunnel exit. Description of the Drawings

[0025] The exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. For clarity, the same components in different drawings are denoted by the same reference numerals. It should be noted that the drawings are only schematic and are not necessarily drawn to scale. In these drawings:

[0026] Figure 1 A configuration diagram of an anti-fog system for a vehicle according to an embodiment of the present invention is shown.

[0027] Figure 2 A schematic diagram illustrating the working process of an anti-fog system for a vehicle according to an embodiment of the present invention is shown.

[0028] Figure 3 A flowchart of an anti-fog method for a vehicle according to an embodiment of the present invention is shown. Detailed implementation manners

[0029] The embodiments of the present invention will be described in detail below. These embodiments are implemented on the premise of the technical solution of the present invention, and detailed implementation manners and specific operation processes are given. However, the protection scope of the present invention is not limited to the following embodiments.

[0030] Hereinafter, the embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0031] Figure 1 A configuration diagram of an anti-fog system for a vehicle according to an embodiment of the present invention is shown. Refer to Figure 1 , the anti-fog system for a vehicle may include: a main control device 100, a position detection device 200, a humidity detection device 300, a vehicle speed detection device 400, a temperature detection device 500, and an illuminance detection device 600. The main control device 100 may be communicatively connected to the position detection device 200, the humidity detection device 300, the vehicle speed detection device 400, the temperature detection device 500, and the illuminance detection device 600 respectively.

[0032] A position detection device 200 (e.g., a Global Positioning System) may be configured to detect the driving position of a vehicle and send the detected driving position of the vehicle to the main control device 100. The Global Positioning System (GPS) may be a representative example of the position detection device 200. Currently, by receiving signals from three or more satellites, the GPS can calculate distance information from the signals after considering accurate time information, and apply triangulation to the calculated distance information to accurately calculate three-dimensional current position (latitude, longitude, and altitude) information. For example, signals transmitted from three satellites are used to calculate location / position and time information, while signals transmitted from another satellite are used to correct errors in the calculated location / position and time information. The GPS can calculate the current position of the vehicle periodically or continuously in real time. The position detection device 200 may be included in an AVNT (AudioVideo Navigation Telecommunication) device. The AVNT device integrates practical functions such as AI intelligent voice control, remote control, real-time mobile phone interconnection, and GPS navigation. The position detection device 200 may also detect navigation information of the vehicle.

[0033] A humidity detection device 300 may be configured to detect the humidity of the external environment of the vehicle. The humidity detection device 300 may be included in the AVNT device, obtain the humidity of the external environment of the vehicle through a wireless communication module using a wireless communication network, and send the obtained humidity of the external environment of the vehicle to the main control device 100. Here, the detected humidity of the external environment of the vehicle is relative humidity, that is, the percentage of the actual water vapor density in the air and the saturated water vapor density at the same temperature.

[0034] According to an embodiment of the present invention, the wireless communication network may include: Global System for Mobile Communication (GSM), Code Division Multiple Access (CDMA), Wideband Code Division Multiple Access (WCDMA), Universal Mobile Telecommunication System (UMTS), Time Division Multiple Access (TDMA), Long Term Evolution (LTE), etc., but the present invention is not limited thereto.

[0035] A vehicle speed detection device 400 (e.g., a wheel speed sensor, a vehicle speed sensor, etc.) can be configured to detect the speed of the vehicle and send the detected vehicle speed to the main control device 100.

[0036] A temperature detection device 500 (e.g., a temperature sensor, etc.) can be configured to detect the temperature of the vehicle's external environment and send the detected temperature of the vehicle's external environment to the main control device 100.

[0037] An illuminance detection device 600 (e.g., an illuminance sensor) can be configured to detect the illuminance level of the vehicle's external environment, convert the illuminance level into an electrical signal (e.g., a voltage signal), and then send it to the main control device 100.

[0038] The main control device 100 can be configured to: obtain the driving position of the vehicle, the driving speed of the vehicle, the temperature, humidity, and illuminance of the vehicle's external environment; based on the driving position of the vehicle, the driving speed of the vehicle, the temperature and humidity of the vehicle's external environment, determine whether there is a fogging risk when the vehicle exits the tunnel before the vehicle exits the tunnel exit; when it is determined that there is a fogging risk when the vehicle exits the tunnel exit, cause the air-conditioning control device to preheat the front windshield in advance. The air-conditioning control device can include an air conditioner temperature control unit (ATCU), a blower speed control unit, etc. The main control device 100 can be a control device such as a Vehicle Control Unit (VCU).

[0039] According to an embodiment of the present invention, communicatively connected can include being connected by means of wired communication and / or wireless communication. The means of wired communication can include Controller Area Network (CAN), Universal Serial Bus (USB), High Definition Multimedia Interface (HDMI), Digital Visual Interface (DVI), etc. Among them, CAN can include a powertrain CAN bus (P_CAN), a body control device CAN bus (B_CAN), a chassis control CAN bus (C_CAN), etc., but the CAN communication method is not limited to the above CAN bus communication method. The means of wireless communication include Global System for Mobile Communications, Code Division Multiple Access, Wideband Code Division Multiple Access, Universal Mobile Telecommunications System, Time Division Multiple Access, Long Term Evolution, etc.

[0040] Therefore, the anti-fog system for a vehicle according to an embodiment of the present invention can predict the fogging risk before the vehicle exits the tunnel exit by utilizing the driving position of the vehicle, the driving speed of the vehicle, and the temperature and humidity of the external environment of the vehicle, and then further preheat the front windshield in advance by using the air-conditioning control device based on the illuminance to avoid the problem of rapid fogging when the vehicle exits the tunnel exit.

[0041] The following will describe Figure 2 the working process of the anti-fog system for a vehicle according to an embodiment of the present invention with reference to Figure 2 . The anti-fog system for a vehicle can operate in the following four stages:

[0042] The first stage: Initial data collection. When the vehicle travels to a predetermined distance D1 from the tunnel entrance, collect the temperature T1 of the external environment of the tunnel, the humidity H1 of the environment, and the illuminance S1.

[0043] The second stage: Fogging risk determination. After the vehicle enters the tunnel entrance, collect the temperature T2 of the internal environment of the tunnel, and determine whether there is a fogging risk when the vehicle exits the tunnel exit based on the temperature difference (T1 - T2) inside and outside the tunnel.

[0044] The third stage: Front windshield preheating treatment. In the case where it is determined that there is a fogging risk when the vehicle exits the tunnel exit, based on the tunnel length L and the distance L0 that the vehicle travels in the tunnel, determine the remaining driving distance L - L0 of the vehicle in the tunnel, so as to determine whether to preheat the front windshield.

[0045] The fourth stage: State recovery. When the vehicle travels to a predetermined distance D2 from the tunnel exit, the air-conditioning control device resumes its normal working state.

[0046] Figure 3 shows a flowchart of the anti-fog method for a vehicle according to an embodiment of the present invention.

[0047] In step S31, the main control device 100 can obtain the driving position and driving speed of the vehicle, so as to calculate the distance between the driving position of the vehicle and the entrance position of the tunnel. The main control device 100 can use the navigation information provided by AVNT to determine the entrance position and exit position of the tunnel.

[0048] In step S32, the main control device 100 can determine whether the vehicle has traveled to a first predetermined distance D1 from the tunnel entrance, that is, compare the driving position of the vehicle with the entrance position of the tunnel to determine whether the distance between the vehicle and the tunnel entrance is less than the first predetermined distance D1. The first predetermined distance D1 can be set to 100 m or any other preset distance, but the aspects of the present invention are not limited to the above specific values.

[0049] When the vehicle travels to a first predetermined distance D1 from the tunnel entrance, at step S33, the main control device 100 may obtain a first temperature T1, a first humidity H1, and a first illuminance S1 of the external environment of the vehicle (i.e., outside the tunnel).

[0050] After the vehicle enters the tunnel entrance, at step S34, the main control device 100 may obtain a second temperature T2 of the external environment of the vehicle (i.e., inside the tunnel), and calculate a temperature difference ΔT between the first temperature T1 and the second temperature T2.

[0051] At step S35, the main control device 100 may compare the calculated temperature difference ΔT with a preset temperature difference ΔT 预设 When the calculated temperature difference ΔT is greater than the preset temperature difference ΔT 预设 it is determined that there is a risk of fogging when the vehicle exits the tunnel exit.

[0052] According to an embodiment of the present invention, the preset temperature difference ΔT 预设 is determined based on the first humidity H1 of the external environment of the vehicle (i.e., outside the tunnel). Table 1 is a mapping table of humidity and temperature difference. Since 90% relative humidity is the condensation state, it is easy to determine the allowable temperature difference for each humidity, that is, the preset temperature difference ΔT 预设 . Therefore, according to the first humidity H1 of the external environment of the vehicle, the corresponding preset temperature difference ΔT can be obtained by looking up Table 1 预设 .

[0053] Table 1

[0054] Humidity H1 (%) <![CDATA[Preset temperature difference ΔT 预设 (°C)]]> H1≤40％ 10℃ 40％＜H1≤50％ 8℃ 50％＜H1≤60％ 6℃ 60％＜H1≤70％ 5℃ 70％＜H1≤80％ 4℃

[0055] For example, when the humidity of the external environment of the tunnel is 70% and the temperature of the external environment of the tunnel is 30 °C, after the vehicle enters the tunnel entrance, if the temperature of the internal environment of the tunnel is 20 °C, the temperature difference is 30 °C - 20 °C = 10 °C, and the calculated temperature difference 10 °C is greater than the preset temperature difference ΔT 预设 (5 °C) corresponding to the humidity of 70% of the external environment of the tunnel, thereby determining that there is a risk of fogging when the vehicle exits the tunnel exit.

[0056] According to an embodiment of the present invention, when it is determined that there is a risk of fogging when the vehicle exits the tunnel exit, it is further determined whether it is necessary to make the air-conditioning control device preheat the front windshield in advance.

[0057] Specifically, when it is determined that there is a risk of fogging when the vehicle exits the tunnel exit, based on the calculated temperature difference ΔT, the first humidity H1, and the first illuminance S1, the allowable driving time t of the vehicle is determined 允许 (S36).

[0058] Since the cooling process of the temperature of the vehicle's front windshield is related not only to the temperature difference but also to the driving time, the allowable driving time t of the vehicle 允许 is determined by t 基本 and t 调整 That is, t 允许 = t 基本 + t 调整 .

[0059] For example, on a sunny day, due to the influence of sunlight, the temperature of the front windshield before entering the tunnel entrance is higher than the ambient temperature of the tunnel after entering the tunnel entrance. Therefore, according to the illuminance, the cooling time of the front windshield (i.e., the allowable driving time of the vehicle) requires an adjustment value that is related to the illuminance outside the tunnel.

[0060] Table 2 is the mapping table of humidity and t 基本 , and according to this table, the basic driving time t of the vehicle corresponding to a certain humidity range can be determined 基本 . That is, through the first humidity H1, the basic driving time t of the vehicle can be determined 基本 .

[0061] Table 2

[0062] Humidity H1 (%) <![CDATA[t 基本 (s)]]> H1≤40％ 180s 40％＜H1≤50％ 120s 50％＜H1≤60％ 100s 60％＜H1≤70％ 80s 70％＜H1≤80％ 60s

[0063] Table 3 is the mapping table of illuminance and t 调整 , and according to this table, the adjusted driving time t of the vehicle corresponding to a certain illuminance range can be determined 调整 . That is, through the first illuminance S1, the adjusted driving time t of the vehicle can be determined 调整 .

[0064] Table 3

[0065] Illuminance (V) <![CDATA[t 基本 (s)]]> S1 ≤ 1.0V 0s 1.0V < S1 ≤ 2.0V 15s S1 > 2.0V 30s

[0066] The sum of the basic driving time t of the vehicle 基本 and the adjusted driving time t of the vehicle 调整 is used to obtain the allowable driving time t of the vehicle 允许 .

[0067] In step S37, the driving time t 行驶 after the vehicle enters the tunnel entrance is compared with the allowable driving time t of the vehicle 允许 to determine whether the driving time t 行驶 after the vehicle enters the tunnel entrance is greater than the allowable driving time t of the vehicle 允许 .

[0068] When the driving time t 行驶 after the vehicle enters the tunnel entrance is greater than the allowable driving time t of the vehicle允许 When (i.e., "Yes" in step S37), in step S38, determine the remaining driving distance L of the vehicle 剩余 , that is, equal to the tunnel length L minus the driving distance L0 of the vehicle in the tunnel, and determine the target temperature of the air outlet of the air-conditioning control device and the blower gear based on the calculated remaining driving distance.

[0069] Table 4 shows the remaining distance L 剩余 and the target temperature T 目标 and the mapping table of the blower gear. According to this table, the target temperature T of the air outlet of the air-conditioning control device corresponding to a certain remaining distance range can be determined 目标 and the blower gear. Among them, T1 is the temperature of the vehicle's external environment (i.e., outside the tunnel).

[0070] Table 4

[0071] Remaining distance <![CDATA[T 目标 > Blower gear <![CDATA[L 剩余 >500m]]> T1 4 <![CDATA[200m < L 剩余 ≤ 500m]]> T1+10℃ 6 <![CDATA[L 剩余 ≤200m]]> T1+20℃ 8

[0072] In step S39, compare the calculated remaining driving distance L 剩余 with the preset remaining distance L1, that is, determine the calculated remaining driving distance L 剩余 whether it is less than the preset remaining distance L1. When the calculated remaining driving distance L 剩余 is less than the preset remaining distance L1 (i.e., "Yes" in step S39), it is determined that the air-conditioning control device needs to preheat the front windshield in advance, so that the air-conditioning control device operates according to the determined target temperature of the air outlet and the blower gear.

[0073] When the driving time t 行驶 after the vehicle enters the tunnel entrance is less than the allowable driving time t 允许 of the vehicle or when the calculated remaining driving distance L 剩余 is greater than the preset remaining distance L1, it is determined that there is no need to preheat the front windshield by the air-conditioning control device in advance.

[0074] Return to refer to Figure 1 , according to the anti-fog system for vehicles according to the embodiments of the present invention, it may further include a display device 700. The display device 700 can be communicably connected to the main control device 100 and can be configured to display a prompt message to the driver when it is determined that there is a risk of fogging. The display device 700 can be included in the AVNT device.

[0075] When it is determined that the vehicle has driven out of the tunnel exit by more than the second predetermined distance D2 (i.e., "Yes" in step S41), the air-conditioning control device is restored to the normal working state. The second predetermined distance D2 can be set to 100 m or any other preset distance, but various aspects of the present invention are not limited to the above specific values.

[0076] Therefore, the anti-fogging method for a vehicle according to an embodiment of the present invention can predict whether there is a risk of fogging when the vehicle exits the tunnel before the vehicle exits the tunnel exit by using the driving position of the vehicle, the driving speed of the vehicle, the temperature and humidity of the external environment of the vehicle. If it is predicted that there is a risk of fogging when the vehicle exits the tunnel exit, the illuminance of the vehicle is further considered, and the air-conditioning control device is used to preheat the front windshield in advance to avoid the problem of rapid fogging when the vehicle exits the tunnel exit.

[0077] The various embodiments of the present invention are not an exhaustive list of all possible combinations, but are intended to describe representative aspects of the present invention, and the content described in the various embodiments can be applied independently or in combinations of two or more.

[0078] The description presented in the above exemplary embodiments is only for illustrating the technical solutions of the present invention, and is not intended to be exhaustive or to limit the present invention to the precise forms described. Obviously, many changes and variations are possible for those of ordinary skill in the art according to the above teachings. The selection of the exemplary embodiments and the description are for explaining the specific principles of the present invention and its practical applications, so that other technicians in the art can understand, implement and utilize the various exemplary embodiments of the present invention and their various alternative forms and modifications. The scope of protection of the present invention is intended to be defined by the appended claims and their equivalents.

Claims

1. A fog prevention system for a vehicle, comprising: a position detection device configured to detect the driving position of the vehicle; a vehicle speed detection device configured to detect the driving speed of the vehicle; a humidity detection device configured to detect the humidity of the external environment of the vehicle; a temperature detection device configured to detect the temperature of the external environment of the vehicle; a light intensity detection device configured to detect the light intensity of the external environment of the vehicle; a main control device communicatively connected to the position detection device, the vehicle speed detection device, the humidity detection device, the temperature detection device, and the light intensity detection device, and configured to: acquire the driving position of the vehicle, the driving speed of the vehicle, the temperature, humidity, and light intensity of the external environment of the vehicle; based on the driving position of the vehicle, the driving speed of the vehicle, the temperature and humidity of the external environment of the vehicle, determine whether there is a fogging risk when the vehicle exits the tunnel exit before the vehicle exits the tunnel exit; when it is determined that there is a fogging risk when the vehicle exits the tunnel exit, further preheat the front windshield in advance by the air-conditioning control device based on the light intensity of the external environment of the vehicle.

2. The fog prevention system for a vehicle according to claim 1, wherein, the main control device is further configured to: when the vehicle travels to a first predetermined distance from the tunnel entrance, acquire the first temperature, the first humidity, and the first light intensity of the external environment of the vehicle; after the vehicle enters the tunnel entrance, acquire the second temperature of the external environment of the vehicle; calculate the temperature difference between the first temperature and the second temperature; compare the calculated temperature difference with a preset temperature difference; when the calculated temperature difference is greater than the preset temperature difference, determine that there is a fogging risk when the vehicle exits the tunnel exit; the preset temperature difference is determined based on the first humidity.

3. The fog prevention system for a vehicle according to claim 2, wherein, the main control device is further configured to: in the case where it is determined that there is a fogging risk when the vehicle exits the tunnel exit, determine the allowable driving time of the vehicle based on the calculated temperature difference, the first humidity, and the first light intensity; compare the driving time after the vehicle enters the tunnel entrance with the allowable driving time of the vehicle; when the driving time after the vehicle enters the tunnel entrance is greater than the allowable driving time of the vehicle, compare the calculated remaining driving distance with a preset remaining distance; when the calculated remaining driving distance is less than the preset remaining distance, determine that it is necessary to preheat the front windshield in advance by the air-conditioning control device.

4. The fog prevention system for a vehicle according to claim 3, wherein, determining the allowable driving time of the vehicle includes: determining the basic driving time of the vehicle through a mapping table of the first humidity and the basic driving time of the vehicle; determining the adjusted driving time of the vehicle through a mapping table of the first light intensity and the adjusted driving time of the vehicle; summing the basic driving time of the vehicle and the adjusted driving time of the vehicle to obtain the allowable driving time of the vehicle.

5. The fog prevention system for a vehicle according to claim 3, wherein, the main control device is further configured to: When the driving time after the vehicle enters the tunnel entrance is less than the allowable driving time of the vehicle or when the calculated remaining driving distance is greater than the preset remaining distance, it is determined that there is no need to preheat the front windshield by the air-conditioning control device in advance.

6. The anti-fog system for a vehicle according to claim 3, wherein, the main control device is further configured to: in the case where it is determined that the air-conditioning control device needs to preheat the front windshield in advance, based on the mapping table of the remaining driving distance, the preset target temperature, and the preset blower gear, determine the preset target temperature and the preset blower gear according to the remaining driving distance, and make the air-conditioning control device work according to the preset target temperature and the preset blower gear.

7. The anti-fog system for a vehicle according to claim 6, wherein, the main control device is further configured to: when it is determined that the vehicle has driven out of the tunnel exit by a second predetermined distance, make the air-conditioning control device resume its normal working state.

8. The anti-fog system for a vehicle according to claim 1, further comprising a display device, the display device being communicatively connected to the main control device and configured to display a prompt message to the driver when it is determined that there is a risk of fogging.

9. The anti-fog system for a vehicle according to claim 1, wherein, communicatively connected includes being connected by means of wired communication; The means of wired communication includes Controller Area Network, Universal Serial Bus, High-Definition Multimedia Interface, and Digital Video Interface.

10. An anti-fog method for a vehicle, which comprises the following steps: Obtain the driving position, driving speed, humidity, temperature, and illuminance of the vehicle external environment of the vehicle; Based on the driving position, driving speed, temperature, and humidity of the vehicle external environment of the vehicle, determine whether there is a risk of fogging when the vehicle drives out of the tunnel exit before the vehicle drives out of the tunnel exit; When it is determined that there is a risk of fogging when the vehicle drives out of the tunnel exit, further preheat the front windshield by the air-conditioning control device based on the illuminance of the vehicle external environment.

11. The anti-fog method for a vehicle according to claim 10, further comprises: When the vehicle travels to a first predetermined distance from the tunnel entrance, obtain the first temperature, first humidity, and first illuminance of the vehicle external environment; After the vehicle enters the tunnel entrance, obtain the second temperature of the vehicle external environment; Calculate the temperature difference between the first temperature and the second temperature; Compare the calculated temperature difference with the preset temperature difference; When the calculated temperature difference is greater than the preset temperature difference, determine that there is a risk of fogging when the vehicle drives out of the tunnel exit; wherein, the preset temperature difference is determined based on the first humidity.

12. The anti-fog method for a vehicle according to claim 11, wherein, in the case where it is determined that there is a risk of fogging when the vehicle drives out of the tunnel exit, it includes: Determine the allowable driving time of the vehicle based on the calculated temperature difference, first humidity, and first illuminance; Compare the driving time after the vehicle enters the tunnel entrance with the allowable driving time of the vehicle; When the driving time after the vehicle enters the tunnel entrance is greater than the allowable driving time of the vehicle, the calculated remaining driving distance is compared with a preset remaining distance; When the calculated remaining driving distance is less than the preset remaining distance, it is determined that the air-conditioning control device needs to preheat the front windshield in advance.

13. The anti-fog method for a vehicle according to claim 12, wherein, Determining the allowable driving time of the vehicle includes: Determining the basic driving time of the vehicle through a mapping table of the first humidity and the basic driving time of the vehicle; Determining the adjusted driving time of the vehicle through a mapping table of the first illuminance and the adjusted driving time of the vehicle; Adding the basic driving time of the vehicle and the adjusted driving time of the vehicle to obtain the allowable driving time of the vehicle.

14. The anti-fog method for a vehicle according to claim 12, wherein, When the driving time after the vehicle enters the tunnel entrance is less than the allowable driving time of the vehicle or when the calculated remaining driving distance is greater than the preset remaining distance, it is determined that the air-conditioning control device does not need to preheat the front windshield in advance.

15. The anti-fog method for a vehicle according to claim 12, wherein, In the case where it is determined that the air-conditioning control device needs to preheat the front windshield in advance, based on a mapping table of the remaining driving distance and a preset target temperature and a preset blower gear, the preset target temperature and the preset blower gear are determined according to the remaining driving distance, and the air-conditioning control device operates according to the preset target temperature and the preset blower gear.

16. The anti-fog method for a vehicle according to claim 15, wherein, When it is determined that the vehicle has exited the tunnel exit by a second predetermined distance, the air-conditioning control device is restored to its normal operating state.

17. The anti-fog method for a vehicle according to claim 10, which further includes: When it is determined that there is a risk of fogging, a prompt message is displayed to the driver.

Images