Anti-fog control method for vehicle windshield

Abstract

The invention provides a vehicle windshield anti-fog control method, which relates to the field of vehicle windshields, and comprises the following steps: after receiving a vehicle power-on signal, obtaining a real-time data set of fogging related parameters; the fogging related parameters at least comprise in-vehicle temperature, out-vehicle temperature, in-vehicle humidity and glass temperature; judging a fogging risk level according to the real-time data set of the fogging related parameters; according to the fogging risk level, a corresponding anti-fogging control strategy is matched, and the anti-fogging control strategy at least comprises a ventilation strategy; the ventilation strategy at least comprises an air conditioner circulation mode, air conditioner blowing intensity and a double-layer flow circulation proportion; a ventilation system of the vehicle is controlled to operate in a ventilation strategy to keep the windshield in an air environment that is not conducive to fogging. According to the scheme, fogging can be effectively prevented, energy consumption can be reduced, fogging of the windshield can be effectively prevented so that the sight definition of a driver can be improved, and the traffic accident risk caused by fogging of the windshield can be greatly reduced.

Description

Technical Field

[0001] The invention relates to the technical field of vehicle windshields, and in particular to a method for controlling the anti-fogging of a vehicle windshield. Background Art

[0002] Windshield fogging is a common problem during vehicle driving. Fogging can seriously affect the driver's vision and pose a great threat to driving safety. Especially under certain climatic conditions, such as rainy days, high humidity environments, or conditions with large temperature differences, fogging is more likely to occur. Traditional vehicle defogger methods usually require the driver to manually operate the air conditioning system or use defoggers, but these methods are often not timely and intelligent enough and cannot automatically adjust the defogger strategy according to actual conditions.

[0003] In the prior art, some vehicles' air-conditioning systems often add a certain defog function in order to solve the problem of defogger being not smart enough. However, this defog function is usually controlled based on a simple temperature or humidity sensor. The risk of fogging is sometimes unable to be accurately judged, resulting in unstable defog effects. Sometimes, excessive defoggering causes energy waste, and sometimes, defogger cannot be effectively used, affecting driving safety. Summary of the invention

[0004] In view of the above defects or shortcomings in the prior art, the present invention aims to provide a vehicle windshield anti-fogging control method to accurately judge the fogging risk; the method comprises the following steps: After receiving the vehicle power-on signal, a real-time data set of fogging-related parameters is obtained; the fogging-related parameters at least include the temperature inside the vehicle, the temperature outside the vehicle, the humidity inside the vehicle, and the glass temperature; Determining the fogging risk level according to the real-time data set of fogging related parameters; According to the fogging risk level, a corresponding anti-fog control strategy is matched, wherein the anti-fog control strategy at least includes a ventilation strategy; the ventilation strategy at least includes an air conditioning circulation mode, an air conditioning blowing intensity, and a double-layer flow circulation ratio; The ventilation system of the vehicle is controlled to operate under the ventilation strategy so that the windshield is constantly in an air environment that is not conducive to the formation of fog.

[0005] According to the technical solution provided by the present invention, the real-time data set of fogging-related parameters is obtained, including obtaining glass temperature data of the glass temperature; The step of obtaining the glass temperature data of the glass temperature specifically comprises the following steps: Determine whether the vehicle has a glass temperature sensor; If so, the first real-time reading of the glass temperature sensor is read as the glass temperature data.

[0006] According to the technical solution provided by the present invention, after determining whether the vehicle has a glass temperature sensor, the following steps are also included: If not, obtaining a predicted glass temperature value based on the vehicle interior temperature and the vehicle exterior temperature; Determine whether the vehicle has a speed sensor and a sunlight sensor; If so, the glass temperature prediction value is corrected by using the second real-time reading of the vehicle speed sensor and the third real-time reading of the sunlight sensor to obtain the glass temperature data.

[0007] According to the technical solution provided by the present invention, obtaining the predicted value of the glass temperature based on the temperature inside the vehicle and the temperature outside the vehicle specifically includes the following steps: Obtaining the accumulated driving time of the vehicle, where the accumulated driving time is the time between the current time and the time when the vehicle power-on signal is received; If the accumulated driving time is less than or equal to a first preset time, the outside temperature is used as the predicted value of the glass temperature.

[0008] According to the technical solution provided by the present invention, after obtaining the accumulated driving time of the vehicle, the following steps are also included: If the accumulated driving time is greater than the first preset time, a time weight function is obtained to obtain a first weight under the accumulated driving time, wherein the first weight is a weight of the influence of the driving time on the glass temperature; Obtaining a second weight, wherein the second weight is related to the air speed of the air conditioner and the relative direction angle between the air outlet and the windshield, and the second weight is the weight of the influence of the air conditioner on the glass temperature; The glass temperature prediction value is obtained according to the first weight, the second weight, the vehicle interior temperature and the vehicle exterior temperature.

[0009] According to the technical solution provided by the present invention, after determining whether the vehicle has a vehicle speed sensor and a sunlight sensor, the following steps are also included: If the vehicle has the vehicle speed sensor but does not have the sunlight sensor, then the relative relationship between the vehicle direction and the sun's direction is obtained; According to the relative relationship of the irradiation and the current time, the irradiation intensity level of the sun on the windshield is obtained; According to the illumination intensity level, obtaining a corresponding first correction coefficient; The glass temperature prediction value is corrected using the first correction coefficient to obtain the glass temperature data.

[0010] According to the technical solution provided by the present invention, after obtaining the corresponding first correction coefficient according to the illumination intensity level, the following steps are also included: Retrieving a vehicle configuration parameter table to obtain windshield information, wherein the windshield information at least includes a windshield color and a windshield tilt angle; Obtaining a corresponding second correction coefficient according to the windshield information; The glass temperature prediction value is corrected according to the first correction coefficient and the second correction coefficient to obtain the glass temperature data.

[0011] According to the technical solution provided by the present invention, matching the corresponding anti-fog control strategy according to the fogging risk level specifically includes the following steps: Retrieve and traverse a strategy database to obtain an anti-fog control strategy corresponding to the fogging risk level; the strategy database at least includes a plurality of fogging risk levels and an anti-fog control strategy corresponding to each of the fogging risk levels.

[0012] According to the technical solution provided by the present invention, after the ventilation system of the vehicle is controlled to operate under the ventilation strategy, the following steps are further included: After the ventilation system of the vehicle operates for a second preset time period under the ventilation strategy, obtaining the fogging amount of the windshield in real time; If the fogging amount is greater than or equal to a second preset threshold, an updated anti-fog control strategy is obtained according to the fogging amount, and the strategy database is updated with the updated anti-fog control strategy.

[0013] According to the technical solution provided by the present invention, obtaining the updated anti-fog control strategy according to the fogging amount specifically includes the following steps: If the air conditioning circulation mode of the ventilation strategy is in the external circulation mode and there is room for increasing the air conditioning blowing intensity, a preset gear increase amount is obtained according to the fogging amount; If the preset gear increase is within the upgradeable gear space, the air conditioning blowing intensity is increased by the preset gear increase as the updated anti-fog control strategy; if the preset gear increase is not within the upgradeable gear space, the air conditioning blowing intensity is increased by the maximum gear increase within the upgradeable gear space, and the double-layer flow circulation ratio is increased as the updated anti-fog control strategy.

[0014] Compared with the prior art, the beneficial effect of the present invention is that by acquiring fogging-related parameters in real time and accurately judging the fogging risk level, the corresponding anti-fogging control strategy can be adopted in time to ensure that the windshield is always in an air environment that is not conducive to the formation of fog, thereby effectively improving the driver's line of sight and greatly reducing the risk of traffic accidents caused by windshield fogging. Moreover, by accurately judging the fogging risk level and matching the corresponding anti-fogging control strategy, unnecessary energy waste can be avoided. In the case of low-risk fogging, the system can adopt a more energy-saving ventilation strategy, such as adjusting the air conditioning circulation mode to external circulation, reducing the air conditioning blowing intensity, etc., which can effectively prevent fogging and reduce energy consumption. Compared with the traditional defogger method, this intelligent control method can reasonably adjust energy use according to actual needs and improve energy utilization efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A flow chart of the steps of the vehicle windshield anti-fogging control method provided by the present invention. DETAILED DESCRIPTION

[0016] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the relevant invention, rather than to limit the invention. It should also be noted that, for ease of description, only the parts related to the invention are shown in the accompanying drawings.

[0017] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0018] Example 1 As mentioned in the background technology, in view of the problems in the prior art, the present invention proposes a vehicle windshield anti-fogging control method to accurately judge the risk of fogging; please refer to Figure 1 As shown, the following steps are included: S1. After receiving a vehicle power-on signal, obtain a real-time data set of fogging-related parameters; the fogging-related parameters at least include the vehicle interior temperature, vehicle exterior temperature, vehicle interior humidity, and glass temperature; Specifically, the control method is executed by the central control unit (ECU), and a real-time data set of fogging-related parameters is collected in real time through multiple sensors installed on the vehicle. The in-vehicle temperature sensor and the in-vehicle humidity sensor are usually installed in appropriate locations in the vehicle, such as near the center console or behind the rearview mirror, to accurately reflect the temperature and humidity conditions in the vehicle. The external temperature sensor is installed on the outside of the vehicle, such as near the front bumper or rearview mirror, to avoid being affected by the vehicle's own heating components. The data collected by each vehicle sensor is transmitted and processed through the vehicle's electronic control system. The data can be transmitted to the vehicle's ECU using communication methods such as the CAN bus, and the ECU monitors and analyzes the data in real time to ensure the accuracy and reliability of the data.

[0019] In a preferred embodiment, the obtaining of the real-time data set of fogging-related parameters includes obtaining glass temperature data of the glass temperature; The step of obtaining the glass temperature data of the glass temperature specifically comprises the following steps: Determine whether the vehicle has a glass temperature sensor; If so, the first real-time reading of the glass temperature sensor is read as the glass temperature data.

[0020] Specifically, the windshields of some mid- to high-end vehicles are equipped with glass temperature sensors. After the vehicle is powered on, the sensor configuration information of the vehicle is queried. The ECU stores the types and status information of various sensors installed in the vehicle, and the information about the presence or absence of the glass temperature sensor can be obtained directly through the ECU. In addition, if the vehicle is equipped with an advanced on-board diagnostic system (OBD), the system can also read the vehicle's sensor list through the OBD interface to determine whether the glass temperature sensor exists. For example, by reading the sensor identification code in the OBD system, it is determined whether there is an identification code corresponding to the glass temperature sensor.

[0021] Furthermore, even if the vehicle is determined to have a glass temperature sensor by the above method, the system needs to further confirm the availability of the glass temperature sensor. This can be achieved by sending a test command to the sensor to see whether valid response data can be received. For example, the system sends a command requesting a temperature reading to the glass temperature sensor determined by the above method. If reasonable temperature data (within the expected temperature range) is received within a certain period of time, the sensor is confirmed to be available. If a valid temperature reading cannot be obtained after multiple attempts, the system may consider the sensor to be faulty or unavailable, and issue an alarm to prompt the driver to check the sensor and use other methods to obtain glass temperature data.

[0022] Furthermore, for most low-end and mid-range vehicles that are not equipped with a glass temperature sensor or when the glass temperature sensor is confirmed to be faulty or unavailable through the above method, the following method can be used to obtain glass temperature data for matching the fogging risk level.

[0023] In a preferred embodiment, after determining whether the vehicle has a glass temperature sensor, the following steps are further included: If not, obtaining a predicted glass temperature value based on the vehicle interior temperature and the vehicle exterior temperature; Determine whether the vehicle has a speed sensor and a sunlight sensor; If so, the glass temperature prediction value is corrected by using the second real-time reading of the vehicle speed sensor and the third real-time reading of the sunlight sensor to obtain the glass temperature data.

[0024] Specifically, the correction method can be determined based on the impact of vehicle speed and sunlight intensity on glass temperature. For example, the higher the vehicle speed, the faster the heat exchange between the vehicle and the outside air, which will make the glass temperature closer to the outside temperature; the stronger the sunlight, the more heat the glass absorbs, and the temperature will rise. A correction model can be established to determine a corresponding correction coefficient based on the vehicle speed and sunlight intensity, and adjust the predicted glass temperature value. Assume that the corrected glass temperature data , where v is the second real-time reading of the vehicle speed sensor, I is the third real-time reading of the sunlight sensor, is the correction coefficient corresponding to the vehicle speed, is the correction coefficient corresponding to the sunlight intensity. Optionally, when the vehicle speed is less than the lower speed limit (vehicle speed is extremely low), the correction coefficient corresponding to the vehicle speed ranges from 0.01 to 0.05, when the vehicle speed is greater than the upper speed limit (vehicle speed is extremely high), the correction coefficient corresponding to the vehicle speed ranges from 0.96 to 0.98, similarly, when the sunlight intensity is less than the lower intensity limit (almost no sunlight), the correction coefficient corresponding to the sunlight intensity ranges from 0.02 to 0.06, when the sunlight intensity is greater than the upper intensity limit (strong sunlight), the correction coefficient corresponding to the vehicle speed ranges from 0.97 to 0.99.

[0025] In a preferred embodiment, obtaining the glass temperature prediction value based on the vehicle interior temperature and the vehicle exterior temperature specifically includes the following steps: Obtaining the accumulated driving time of the vehicle, where the accumulated driving time is the time between the current time and the time when the vehicle power-on signal is received; If the accumulated driving time is less than or equal to a first preset time, the outside temperature is used as the predicted value of the glass temperature.

[0026] Specifically, the duration between the current time and the time when the vehicle power-on signal is received is calculated through the vehicle's electronic clock and the vehicle power-on time recorded by the system, which is the cumulative driving time. For example, the vehicle is powered on at 10:00 in the morning and the current time is 10:15, so the cumulative driving time is 15 minutes. If the cumulative driving time is less than or equal to the first preset time (for example: the first preset time is 5 minutes), the outside temperature is used as the predicted value of the glass temperature. This is because during this period of time when the vehicle has just been started, the glass temperature is mainly affected by the outside environment and has not yet been significantly affected by factors inside the vehicle. For example, the outside temperature is 20°C, and the predicted value of the glass temperature is 20°C.

[0027] In a preferred embodiment, after obtaining the accumulated driving time of the vehicle, the following steps are further included: If the accumulated driving time is greater than the first preset time, a time weight function is obtained to obtain a first weight under the accumulated driving time, wherein the first weight is a weight of the influence of the driving time on the glass temperature; Obtaining a second weight, wherein the second weight is related to the air speed of the air conditioner and the relative direction angle between the air outlet and the windshield, and the second weight is the weight of the influence of the air conditioner on the glass temperature; The glass temperature prediction value is obtained according to the first weight, the second weight, the vehicle interior temperature and the vehicle exterior temperature.

[0028] Specifically, if the cumulative driving time exceeds 5 minutes, a time weight function is defined, for example, an exponential decay function or a linear function can be used. Assuming that a linear function is used , where t is the cumulative driving time, a is an adjustment parameter (which can be determined based on actual tests, assuming a=10), is the first weight. As the driving time increases, this weight gradually increases from close to 0 to close to 1, indicating that the impact of driving time on glass temperature gradually increases. For example, when the cumulative driving time is 10 minutes, is 0.5.

[0029] Optionally, the air conditioning wind speed and the relative direction angle between the air outlet and the windshield are input into a weight calculation model to obtain a second weight, wherein the weight calculation model is obtained by training a first training sample set, the first training sample set includes a plurality of groups of first input samples and a first output sample corresponding to each group of the first input samples, the first input sample is the air conditioning wind speed, the relative direction angle between the air outlet and the windshield, and the first output sample is a second weight corresponding to the air conditioning wind speed, the relative direction angle between the air outlet and the windshield. Then according to the formula The predicted value of glass temperature can be obtained, where is the predicted value of glass temperature, is the temperature inside the car, is the outside temperature, is the second weight, is the outlet temperature, It is a coefficient (usually ranging from 0 to 1) determined based on factors such as the vehicle's thermal insulation performance.

[0030] Furthermore, the formula for predicting the glass temperature is It belongs to the driving time weight part. is the time weight factor, For air conditioning factors, This belongs to the part of outdoor temperature compensation. An example is given below to prove the accuracy of the formula.

[0031] For example, in one application scenario, is 20 degrees, is 25 degrees, is 18 degrees, the air conditioning wind speed is medium and the angle between the air outlet and the windshield is 45 degrees (obtained by inputting into the weight calculation model is 0.5, the vehicle's thermal insulation performance is average (so set is 0.6), and the adjustment parameter a is still the same as above, that is, 10. Then when the driving time is 5 minutes (just exceeding the first preset time), the predicted glass temperature value calculated by the above formula is 20.2 degrees, when the driving time is 15 minutes, the predicted glass temperature value calculated by the above formula is 20.3 degrees, and when the driving time is 30 minutes, the predicted glass temperature value calculated by the above formula is about 20.375 degrees. From this example, it can be seen that with the increase of driving time, the predicted glass temperature value is gradually affected more by the temperature inside the car and air-conditioning factors, but the basic role of the temperature outside the car is always comprehensively considered. And under different driving times, the change of the predicted value is consistent with the changing trend of the impact of the internal and external environments of the vehicle on the glass temperature in actual situations.

[0032] In a preferred embodiment, after determining whether the vehicle has a vehicle speed sensor and a sunlight sensor, the following steps are further included: If the vehicle has the vehicle speed sensor but does not have the sunlight sensor, then the relative relationship between the vehicle direction and the sun's direction is obtained; Specifically, the vehicle's orientation information (such as whether the front of the vehicle is pointing north, south, east, west, etc.) is obtained through the vehicle's electronic compass or navigation system. At the same time, the position of the sun in the sky is calculated based on the date, time and vehicle location (obtained through GPS). For example, in the northern hemisphere, the sun is roughly in the eastern sky in the morning. If the front of the vehicle is facing east, the windshield is more likely to be exposed to sunlight.

[0033] According to the relative relationship of the irradiation and the current time, the irradiation intensity level of the sun on the windshield is obtained; Specifically, according to the relative relationship between the vehicle's orientation and the sun's position, combined with the time of day, the sun's irradiation intensity on the windshield is divided into several levels, such as no irradiation, weak irradiation, medium irradiation, and strong irradiation. For example, in the morning or evening, the angle of sunlight is relatively large, which may be determined as weak irradiation; at noon, if the vehicle is facing the sun, it is determined as strong irradiation.

[0034] According to the illumination intensity level, obtaining a corresponding first correction coefficient; Exemplarily, when the irradiation is weak, the first correction coefficient is 0.1-0.2; when the irradiation is medium, the first correction coefficient is 0.3-0.5; when the irradiation is strong, the first correction coefficient is 0.6-0.8.

[0035] The glass temperature prediction value is corrected using the first correction coefficient to obtain the glass temperature data.

[0036] Specifically, through the formula Calculate the glass temperature data, where is the glass temperature data, is the predicted value of glass temperature, is the temperature inside the car, is the first correction coefficient.

[0037] This embodiment evaluates the effect of sunlight on the glass temperature of the vehicle windshield through the relative direction of the vehicle and the sun, and then obtains glass temperature data. It also provides a software-side usage method for vehicles that are not equipped with a glass temperature sensor, making the control method more applicable.

[0038] Furthermore, by considering the influence of sunlight intensity on glass temperature, the predicted glass temperature value is corrected using the first correction coefficient corresponding to the illumination intensity level to obtain more accurate glass temperature data. In addition, in addition to sunlight intensity, the performance of the windshield itself also affects the glass's absorption of sunlight heat. Therefore, this embodiment further proposes another correction strategy to obtain more accurate glass temperature data. Specifically, after obtaining the corresponding first correction coefficient according to the illumination intensity level, the following steps are also included: Retrieving a vehicle configuration parameter table to obtain windshield information, wherein the windshield information at least includes a windshield color and a windshield tilt angle; Obtaining a corresponding second correction coefficient according to the windshield information; Specifically, windshields of different colors have different abilities to absorb sunlight. For example, dark-colored glass absorbs more solar radiation than light-colored glass. The tilt angle of the windshield affects the angle between the windshield and the direction of sunlight, and thus also affects the glass's absorption of sunlight. A windshield that is more perpendicular to the direction of sunlight absorbs more solar radiation per unit area than a relatively tilted windshield.

[0039] Specifically, the first correction coefficient is obtained through a first correction coefficient model, the input of the first correction coefficient model is the solar radiation intensity level, and the output is the first correction coefficient. The second correction coefficient is obtained through a second correction coefficient model, the input of the second correction coefficient model is the windshield information, and the output is the second correction coefficient.

[0040] The glass temperature prediction value is corrected according to the first correction coefficient and the second correction coefficient to obtain the glass temperature data.

[0041] Furthermore, the step of correcting the glass temperature prediction value according to the first correction coefficient and the second correction coefficient to obtain the glass temperature data specifically includes the following steps: Obtaining a first variation according to a first correction coefficient, the vehicle interior temperature, and a predicted value of the glass temperature; Obtaining a second change amount according to the first change amount and the second correction coefficient; The second variation is added to the predicted glass temperature value to obtain the glass temperature data.

[0042] Specifically, the correction process is considered as first considering the influence of the solar radiation intensity level on the basis of the predicted value of the glass temperature, so that the temperature produces a change (the first change). The first change is the product of the absolute value of the difference between the temperature inside the car and the predicted value of the glass temperature and the first correction coefficient. Here, the absolute value of the difference between the temperature inside the car and the predicted value of the glass temperature is the temperature difference between the interior environment and the current predicted glass temperature. Because the change in solar radiation intensity will cause the glass temperature to change in the direction of the temperature inside the car, the first correction coefficient represents the degree of this change. Then, the influence of the windshield's own characteristics is considered, that is, the product of the first change and the second correction coefficient is taken as the second change. Since the windshield's own characteristics (color and tilt angle) will change the degree of absorption of solar radiation, it will further affect the change of glass temperature.

[0043] For example, is 20 degrees, is 25 degrees, the first correction coefficient calculated by the first correction coefficient model is 0.6, and the second correction coefficient calculated by the second correction coefficient model is 0.7, so the first change is 0.6 (25-20) = 3 degrees, the second change is 0.7 3=2.1 degrees, the glass temperature data is 20+2.1 degrees=22.1 degrees.

[0044] This embodiment not only takes into account the relative direction between the vehicle and the sun, but also takes into account the effect of the color and tilt angle of the vehicle windshield on the degree of absorption of solar thermal radiation on the glass temperature, thereby further improving the accuracy of the glass temperature data obtained through software prediction.

[0045] S2. judging the fogging risk level according to the real-time data set of fogging-related parameters; Specifically, a fogging risk assessment model is established according to fogging-related parameters, and the fogging risk assessment model is installed on the ECU. The fogging risk assessment model can adopt a simple weighting method.

[0046] For example, taking the simple weighted method as an example, first determine the relative importance of each parameter to the risk of fogging and assign different weights. The weight of the temperature difference between inside and outside the car can be set to 0.3, the weight of the humidity inside the car is 0.3, the weight of the humidity outside the car is 0.2, and the weight of the glass temperature is 0.2. Then set different risk level intervals for each parameter and assign corresponding scores. The temperature difference between inside and outside the car is less than 5°C, which is a low risk and assigned a value of 1; 5°C - 10°C is a medium risk and assigned a value of 2; greater than 10°C is a high risk and assigned a value of 3. The humidity inside the car is less than 50% for low risk and assigned a value of 1; 50% - 70% for medium risk and assigned a value of 2; greater than 70% for high risk and assigned a value of 3. And so on, determine the score of each parameter at different risk levels. Finally, multiply the score of each parameter by its corresponding weight and add them together to obtain a comprehensive risk score. The fog risk level is determined based on the comprehensive risk score. For example, a comprehensive risk score between 1 and 1.5 is low risk, between 1.5 and 2.5 is medium risk, and between 2.5 and 3 is high risk.

[0047] Specifically, during vehicle driving, the real-time data set of fogging-related parameters is updated at regular intervals (such as a few seconds or minutes), and the fogging risk level is recalculated to ensure that the system can respond to environmental changes in a timely manner and adjust the anti-fog control strategy.

[0048] S3. According to the fogging risk level, a corresponding anti-fog control strategy is matched, wherein the anti-fog control strategy at least includes a ventilation strategy; the ventilation strategy at least includes an air conditioning circulation mode, an air conditioning blowing intensity and a double-layer flow circulation ratio; further, the ventilation strategy also includes a blowing direction of the vent.

[0049] In a preferred embodiment, matching the corresponding anti-fog control strategy according to the fogging risk level specifically includes the following steps: Retrieve and traverse a strategy database to obtain an anti-fog control strategy corresponding to the fogging risk level; the strategy database at least includes a plurality of fogging risk levels and an anti-fog control strategy corresponding to each of the fogging risk levels.

[0050] Exemplarily, the strategy database includes a low risk level, a medium risk level, and a high risk level. The anti-fog control strategy corresponding to the low risk level is: the air conditioning circulation mode is the air conditioning external circulation state, the double-layer flow circulation ratio is set to a lower level, such as 1:3 (the ratio of external circulation air to internal circulation air), and the air conditioning blowing intensity is set to a low gear, such as wind speed 1-2 gears. The blowing direction of the vent is adjusted to avoid blowing directly to the windshield, ensuring that the air in the car can circulate naturally and gently, maintaining the relative stability of the air humidity and temperature in the car, and preventing fogging. The anti-fog control strategy corresponding to the medium risk level is: the air conditioning circulation mode is the air conditioning external circulation state, the double-layer flow circulation ratio is appropriately increased to about 1:2, the air conditioning blowing intensity is adjusted to a medium gear, such as wind speed 3-4 gears, and the vent direction is adjusted to blow obliquely upward to the front windshield, using the ventilation airflow to take away the water vapor that may liquefy on the glass surface, reducing the possibility of fogging. The anti-fog control strategy corresponding to the high risk level is: immediately open the air conditioning external circulation to the maximum, close to the 1:1 double-layer flow circulation ratio, adjust the air conditioning blowing intensity to a high level, and ensure that the vents blow accurately to the front windshield to form a strong airflow to prevent fog from forming. If fog has already appeared on the glass, if the vehicle ventilation system has a defog mode, you can also turn on the defog mode, which usually combines strong winds and appropriate temperature adjustment to quickly defog.

[0051] S4. Controlling the ventilation system of the vehicle to operate under the ventilation strategy so that the windshield is continuously in an air environment that is not conducive to fog formation.

[0052] Specifically, the ventilation system of the vehicle consists of an air conditioning system, ventilation ducts, vents, etc. According to the matching anti-fog control strategy, the ventilation system is controlled by the ECU. For example, if the strategy requires adjusting the air conditioning circulation mode to external circulation, the system will send a corresponding control signal to the air conditioning controller to switch it to the external circulation mode. Similarly, the adjustment of the air conditioning blowing intensity and the double-layer flow circulation ratio is also sent to the corresponding actuator for adjustment through a control signal. In the process of controlling the operation of the ventilation system, the response speed and accuracy of each actuator must be ensured. For example, the wind direction adjustment of the vent can be achieved by electrically adjusting the angle of the blade, and the system must ensure that the blade can be adjusted to the specified angle quickly and accurately. At the same time, the operating status of the ventilation system must be monitored in real time, such as whether the wind speed of the vent reaches the set value, whether the air conditioning circulation mode is correctly switched, etc. If it is found that the actuator fails or the operating status is abnormal, the corresponding fault diagnosis and treatment measures must be taken in time to ensure that the ventilation system can operate normally.

[0053] In a preferred embodiment, after the ventilation system of the vehicle is controlled to operate under the ventilation strategy, the method further comprises the following steps: After the ventilation system of the vehicle operates for a second preset time period under the ventilation strategy, obtaining the fogging amount of the windshield in real time; Specifically, if the vehicle is equipped with a dedicated fogging sensor, the sensor data can be directly read to determine the amount of fogging. If there is no dedicated sensor, the windshield image can be captured by a camera and the amount of fogging can be estimated through an image analysis algorithm. For example, by analyzing the grayscale value, contrast and other features of the image, the degree of fogging can be determined and quantified as the amount of fogging.

[0054] If the fogging amount is greater than or equal to a second preset threshold, an updated anti-fog control strategy is obtained according to the fogging amount, and the strategy database is updated with the updated anti-fog control strategy.

[0055] Specifically, it is assumed that the second preset threshold is that 50% of the windshield area is covered by fog.

[0056] Specifically, this embodiment feeds back the anti-fog effect of the anti-fog control strategy after matching the corresponding anti-fog control strategy in the database. If the amount of fogging is small, it means that the air environment under this operating mode is suitable. Otherwise, it means that the anti-fog effect of the anti-fog control strategy stored in the database is not good and needs to be updated in time. The specific updating method is given below.

[0057] Further, obtaining an updated anti-fog control strategy according to the fogging amount specifically comprises the following steps: If the air conditioning circulation mode of the ventilation strategy is in the external circulation mode and there is room for increasing the air conditioning blowing intensity, a preset gear increase amount is obtained according to the fogging amount; If the preset gear increase is within the upgradeable gear space, the air conditioning blowing intensity is increased by the preset gear increase as the updated anti-fog control strategy; if the preset gear increase is not within the upgradeable gear space, the air conditioning blowing intensity is increased by the maximum gear increase within the upgradeable gear space, and the double-layer flow circulation ratio is increased as the updated anti-fog control strategy.

[0058] For example, if the current air-conditioning blowing intensity is medium, then the gear space that can be increased is one gear (one gear is from medium to high), and the preset gear increase is one gear, which means that the preset gear increase is within the gear space that can be increased (the preset gear increase is less than or equal to the gear space that can be increased), and the air-conditioning blowing intensity is increased by one gear to high, and the anti-fog control strategy corresponding to the fogging risk level is updated from the original external circulation mode, air-conditioning blowing intensity medium, and double-layer flow circulation ratio of 1:2 to external circulation mode, air-conditioning blowing intensity high, and double-layer flow circulation ratio of 1:2. If the current air conditioning blowing intensity is high, it means that the gear space that can be upgraded is zero, the preset gear increase is not within the gear space that can be upgraded, and the gear cannot be upgraded any further, so the air conditioning blowing intensity is maintained at high, and the double-layer flow circulation ratio is increased from the current 1:2 to 1:1, and the anti-fog control strategy corresponding to the fogging risk level is updated from the original external circulation mode, high-level air conditioning blowing intensity, and double-layer flow circulation ratio of 1:2 to external circulation mode, high-level air conditioning blowing intensity, and double-layer flow circulation ratio of 1:1.

[0059] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core ideas. The above is only a preferred implementation method of the present invention. It should be pointed out that due to the limitations of textual expression, there are objectively infinite specific structures. For ordinary technicians in this technical field, without departing from the principles of the present invention, several improvements, modifications or changes can be made, and the above technical features can be combined in an appropriate manner; these improvements, modifications, changes or combinations, or the direct application of the inventive concept and technical solution to other occasions without improvement, should be regarded as the protection scope of the present invention.

Claims

1. A method for controlling the anti-fogging of a vehicle windshield, characterized in that: The following steps are involved: After receiving the vehicle power-on signal, a real-time data set of fogging-related parameters is obtained; the fogging-related parameters at least include the temperature inside the vehicle, the temperature outside the vehicle, the humidity inside the vehicle, and the glass temperature; Determining the fogging risk level according to the real-time data set of fogging related parameters; According to the fogging risk level, a corresponding anti-fog control strategy is matched, wherein the anti-fog control strategy at least includes a ventilation strategy; the ventilation strategy at least includes an air conditioning circulation mode, an air conditioning blowing intensity, and a double-layer flow circulation ratio; The ventilation system of the vehicle is controlled to operate under the ventilation strategy so that the windshield is constantly in an air environment that is not conducive to the formation of fog.

2. The vehicle windshield anti-fogging control method according to claim 1, characterized in that: The real-time data set of fogging-related parameters is obtained, including glass temperature data of the glass temperature; The step of obtaining the glass temperature data of the glass temperature specifically comprises the following steps: Determine whether the vehicle has a glass temperature sensor; If so, the first real-time reading of the glass temperature sensor is read as the glass temperature data.

3. The vehicle windshield anti-fogging control method according to claim 2, characterized in that: After determining whether the vehicle has a glass temperature sensor, the following steps are also included: If not, obtaining a predicted glass temperature value based on the vehicle interior temperature and the vehicle exterior temperature; Determine whether the vehicle has a speed sensor and a sunlight sensor; If so, the glass temperature prediction value is corrected by using the second real-time reading of the vehicle speed sensor and the third real-time reading of the sunlight sensor to obtain the glass temperature data.

4. The vehicle windshield anti-fogging control method according to claim 3, characterized in that: The step of obtaining a predicted glass temperature value based on the vehicle interior temperature and the vehicle exterior temperature specifically includes the following steps: Obtaining the accumulated driving time of the vehicle, where the accumulated driving time is the time between the current time and the time when the vehicle power-on signal is received; If the accumulated driving time is less than or equal to a first preset time, the outside temperature is used as the predicted value of the glass temperature.

5. The vehicle windshield anti-fogging control method according to claim 4, characterized in that: After obtaining the accumulated driving time of the vehicle, the following steps are also included: If the accumulated driving time is greater than the first preset time, a time weight function is obtained to obtain a first weight under the accumulated driving time, wherein the first weight is a weight of the influence of the driving time on the glass temperature; Obtaining a second weight, wherein the second weight is related to the air speed of the air conditioner and the relative direction angle between the air outlet and the windshield, and the second weight is the weight of the influence of the air conditioner on the glass temperature; The glass temperature prediction value is obtained according to the first weight, the second weight, the vehicle interior temperature and the vehicle exterior temperature.

6. The vehicle windshield anti-fogging control method according to claim 3, characterized in that: After determining whether the vehicle has a vehicle speed sensor and a sunlight sensor, the following steps are also included: If the vehicle has the vehicle speed sensor but does not have the sunlight sensor, then the relative relationship between the vehicle direction and the sun's direction is obtained; According to the relative relationship of the irradiation and the current time, the irradiation intensity level of the sun on the windshield is obtained; According to the illumination intensity level, obtaining a corresponding first correction coefficient; The glass temperature prediction value is corrected using the first correction coefficient to obtain the glass temperature data.

7. The vehicle windshield anti-fogging control method according to claim 6, characterized in that: After obtaining the corresponding first correction coefficient according to the illumination intensity level, the following steps are also included: Retrieving a vehicle configuration parameter table to obtain windshield information, wherein the windshield information at least includes a windshield color and a windshield tilt angle; Obtaining a corresponding second correction coefficient according to the windshield information; The glass temperature prediction value is corrected according to the first correction coefficient and the second correction coefficient to obtain the glass temperature data.

8. The vehicle windshield anti-fogging control method according to claim 1, characterized in that: The step of matching a corresponding anti-fog control strategy according to the fogging risk level specifically includes the following steps: Retrieve and traverse a strategy database to obtain an anti-fog control strategy corresponding to the fogging risk level; the strategy database at least includes a plurality of fogging risk levels and an anti-fog control strategy corresponding to each of the fogging risk levels.

9. The vehicle windshield anti-fogging control method according to claim 8, characterized in that: After the ventilation system of the vehicle is controlled to operate under the ventilation strategy, the method further comprises the following steps: After the ventilation system of the vehicle operates for a second preset time period under the ventilation strategy, obtaining the fogging amount of the windshield in real time; If the fogging amount is greater than or equal to a second preset threshold, an updated anti-fog control strategy is obtained according to the fogging amount, and the strategy database is updated with the updated anti-fog control strategy.

10. The vehicle windshield anti-fogging control method according to claim 9, characterized in that: The step of obtaining an updated anti-fog control strategy according to the fogging amount specifically comprises the following steps: If the air conditioning circulation mode of the ventilation strategy is in the external circulation mode and there is room for increasing the air conditioning blowing intensity, a preset gear increase amount is obtained according to the fogging amount; If the preset gear increase is within the upgradeable gear space, the air conditioning blowing intensity is increased by the preset gear increase as the updated anti-fog control strategy; if the preset gear increase is not within the upgradeable gear space, the air conditioning blowing intensity is increased by the maximum gear increase within the upgradeable gear space, and the double-layer flow circulation ratio is increased as the updated anti-fog control strategy.

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