Vehicle cooling liquid leakage monitoring method and system

Abstract

The invention discloses a vehicle cooling liquid leakage monitoring method and system, and belongs to the technical field of vehicle cooling. The method comprises the following steps: acquiring a coolant pump duty ratio sequence of the vehicle cooling system in a plurality of continuous preset time periods in real time; the duty ratio standard deviation of each preset time period is calculated according to the coolant pump duty ratio sequence; whether the duty ratio standard deviation in each preset time period is larger than a standard deviation threshold value or not is judged; and when the duty ratio standard deviation in the at least two preset time periods is larger than the standard deviation threshold value, whether the cooling liquid leaks or not is judged according to whether the at least two continuous preset time periods exist or not. According to the method, whether the cooling liquid leaks or not is determined based on the duty ratio and the time, the leakage of the cooling liquid of the cooling system can be accurately and continuously monitored in real time, missing detection and false detection are effectively prevented, and the problem that the leakage of the cooling liquid cannot be accurately and continuously monitored in real time through a traditional method is solved.

Description

Technical Field

[0001] The present application belongs to the field of vehicle cooling technology, relates to vehicle coolant leakage monitoring technology, and particularly relates to a vehicle coolant leakage monitoring method and system. Background Art

[0002] In the modern automotive industry, with ever-increasing vehicle performance requirements and increasing technological complexity, cooling systems have become a critical component for ensuring the proper operation of engines and powertrains. Engines generate significant heat during operation. If this heat cannot be dissipated promptly, it can lead to engine overheating, which can cause a range of issues, including reduced engine performance, component damage, and even fires. Therefore, the health of the cooling system is directly linked to vehicle safety and reliability.

[0003] Coolant leaks are a common problem in automotive cooling systems. Traditional methods for detecting coolant leaks rely primarily on regular maintenance and visual inspections, such as observing the coolant tank level and checking for leaks on the outside of the cooling system. Regular inspections are time-consuming and labor-intensive, inefficient, and costly, with high rates of missed and false positives. They also fail to accurately and continuously detect coolant leaks in real time. Summary of the Invention

[0004] The embodiments of the present application provide a vehicle coolant leakage monitoring method and system, which can monitor coolant leakage in the cooling system in real time, accurately and continuously, effectively prevent missed detection and false detection, and solve the problem that traditional methods cannot achieve real-time, accurate and continuous monitoring of coolant leakage.

[0005] In a first aspect, a vehicle coolant leakage monitoring method is provided, which is applied to a vehicle. The monitoring method comprises: Real-time acquisition of a coolant pump duty cycle sequence of a vehicle cooling system within a plurality of consecutive preset time periods; Calculating a duty cycle standard deviation for each preset time period based on the coolant pump duty cycle sequence; Determine whether the duty cycle standard deviation in each preset time period is greater than a standard deviation threshold; When the duty cycle standard deviation is greater than the standard deviation threshold in at least two preset time periods, whether the coolant leaks is determined based on whether there are at least two consecutive preset time periods.

[0006] When a coolant leak occurs in the cooling system, it results in insufficient coolant flow. The electronic control unit (MCU) frequently adjusts the coolant pump duty cycle to maintain coolant flow (for example, increasing the duty cycle but delaying the response). This can cause the duty cycle to oscillate more rapidly. In an embodiment of the present application, based on duty cycle fluctuations, the standard deviation of the duty cycle within each preset time period is calculated from a real-time sequence of the vehicle cooling system's coolant pump duty cycles acquired over multiple preset time periods. A duty cycle standard deviation greater than a standard deviation threshold is used as a first necessary condition for a coolant leak, and a second necessary condition for a coolant leak is used to determine if the coolant leak has occurred. This method of monitoring the coolant pump's duty cycle changes can detect anomalies even when the leak is minimal, quickly and accurately capturing early signs of a coolant leak and issuing a timely alarm. This allows the user to take action to prevent the leak from escalating and allows maintenance work to be performed before the leak worsens, thereby protecting the engine from high-temperature damage and effectively extending the vehicle's service life.

[0007] In combination with the first aspect, in certain implementations of the first aspect, the monitoring method further includes: determining whether the coolant is leaking based on a coolant pump speed error; the method for determining whether the coolant is leaking based on the coolant pump speed error is: Real-time acquisition of vehicle cooling system status parameters over multiple consecutive preset time periods; Calculating a duty cycle change rate sequence according to the duty cycle sequence; Obtaining a predicted speed of the coolant pump through a speed prediction model according to the state parameters, the duty cycle sequence, and the duty cycle change rate sequence; Calculating a coolant pump speed error for each preset time period based on the actual coolant pump speed and the predicted coolant pump speed; Determining whether the coolant pump speed error is greater than an error threshold within each preset time period; When the coolant pump speed error is greater than the error threshold in at least two preset time periods, it is determined whether the coolant is leaking based on whether there are at least two consecutive preset time periods.

[0008] In a vehicle's cooling system, the speed of the coolant pump is typically closely related to engine speed, coolant flow rate, and other parameters. When a coolant leak occurs, the pressure and flow rate within the cooling system decrease, requiring the coolant pump to rotate at a higher speed to maintain the same cooling effect. In an embodiment of the present application, based on the change in coolant pump speed, a speed prediction model is used to predict the predicted coolant pump speed by monitoring the actual coolant pump speed and combining it with the coolant pump duty cycle, duty cycle change rate, coolant temperature, and coolant pressure. Based on the difference between the actual and predicted coolant pump speeds (i.e., the coolant pump speed error), a coolant pump speed error greater than an error threshold is used as a first necessary condition for coolant leakage. A second necessary condition for coolant leakage is determined by satisfying the first necessary condition for at least two consecutive preset time periods. This approach can detect anomalies while the amount of coolant leakage is still small, providing a timely alarm and enabling the user to take action to prevent the leakage problem from escalating. This allows maintenance work to be performed before the leakage problem worsens, thereby protecting the engine from high-temperature damage and effectively extending the service life of the vehicle.

[0009] In conjunction with the first aspect, in certain implementations of the first aspect, a method for determining whether coolant has leaked based on whether at least two consecutive preset time periods exist is: Determine whether there are at least two consecutive preset time periods; When there are at least two consecutive preset time periods, it is determined that there is a coolant leak; otherwise, it is determined that there is no coolant leak.

[0010] In an embodiment of the present application, based on a multiple time window voting method, by satisfying the leakage condition (i.e., the duty cycle standard deviation is greater than the standard deviation threshold or the coolant pump speed error is greater than the error threshold) for multiple consecutive preset time periods (i.e., time windows), false detections are effectively reduced and the accuracy of coolant leakage monitoring is improved.

[0011] In combination with the first aspect, in certain implementations of the first aspect, the method for constructing the speed prediction model is: using the state parameters and PWM characteristic parameters of the vehicle cooling system as input features, and using the predicted speed of the coolant pump as output features to construct the speed prediction model.

[0012] In automotive cooling systems, PWM characteristic parameters typically refer to parameters related to pulse width modulation (PWM), which are used to control the speed of the coolant pump to regulate the engine coolant flow. In this embodiment, a speed prediction model is constructed using the vehicle cooling system's state parameters and PWM characteristic parameters as input features. This model accurately predicts the ideal speed required by the coolant pump based on the vehicle cooling system's real-time state parameters (such as coolant temperature, pressure, and flow) and PWM characteristic parameters (such as duty cycle, frequency, and duty cycle change rate).

[0013] In conjunction with the first aspect, in certain implementations of the first aspect, the method for constructing the speed prediction model further includes: training the speed prediction model; the method for training the speed model is: Acquire historical PWM characteristic parameter data and historical cooling system state parameter data of the vehicle cooling system as training samples; the historical PWM characteristic parameter data includes duty cycle and duty cycle change rate, and the historical cooling system state parameter data includes coolant temperature and coolant pressure; The speed prediction model is trained using training samples to obtain a trained speed prediction model.

[0014] In an embodiment of the present application, historical PWM characteristic parameter data of the vehicle cooling system and historical cooling system state parameter data are used as training samples. The speed prediction model is trained by using the training samples, which can significantly improve the prediction accuracy and generalization ability of the speed prediction model and achieve accurate prediction of the target speed of the coolant pump.

[0015] In conjunction with the first aspect, in certain implementations of the first aspect, the state parameter further includes coolant temperature; and the monitoring method further includes: When the duty cycle standard deviation is greater than a standard deviation threshold or the coolant pump speed error is greater than an error threshold in at least two consecutive preset time periods, it is determined whether the coolant is leaking based on the coolant temperature.

[0016] The coolant temperature directly reflects the thermal load of the engine and the cooling system. The change in coolant temperature is an important dynamic indicator during the operation of the cooling system. When the coolant leaks, the amount of coolant decreases, resulting in a decrease in heat dissipation capacity and an increase in the coolant temperature. In an embodiment of the present application, the coolant temperature is introduced. On the basis of judging coolant leakage based on duty cycle fluctuations or changes in coolant pump speed, combined with the coolant temperature change, the duty cycle standard deviation greater than the standard deviation threshold or the coolant pump speed error greater than the error threshold is used as the main condition for satisfying coolant leakage, and the coolant temperature is used as an auxiliary judgment parameter for coolant leakage to judge whether the coolant is leaking. This multi-parameter comprehensive judgment method can improve the accuracy of coolant leakage monitoring and reduce the missed detection and false detection rates.

[0017] In conjunction with the first aspect, in certain implementations of the first aspect, a method for determining whether coolant is leaking based on the coolant temperature is: Determine whether the coolant temperature is greater than a coolant temperature threshold; If the coolant temperature is greater than the coolant temperature threshold and lasts for a first set time, it is determined that the coolant is leaking; otherwise, it is determined that there is no coolant leakage.

[0018] In this embodiment, a coolant temperature exceeding a coolant temperature threshold for a first set time period is considered a coolant leak condition. By setting both the coolant temperature threshold and the duration, a dual coolant temperature and time determination mechanism is established, avoiding misjudgments due to short-term coolant temperature fluctuations or accidental factors, thereby improving the accuracy of coolant leak detection.

[0019] In conjunction with the first aspect, in certain implementations of the first aspect, the state parameter further includes coolant pressure; and the monitoring method further includes: In at least two consecutive preset time periods, if the duty cycle standard deviation is greater than the standard deviation threshold or the coolant pump speed error is greater than the error threshold, it is determined whether the coolant is leaking based on the coolant pressure.

[0020] There is a close correlation between coolant leakage and coolant pressure. Changes in coolant pressure may be the direct cause of coolant leakage or the result of coolant leakage. Coolant leakage will cause a decrease in the amount of coolant in the cooling system. When the amount of coolant is insufficient, the circulation of the coolant will be affected, and the coolant cannot fill the entire cooling system, resulting in a decrease in coolant pressure. For example, when coolant leaks from the radiator, the coolant level in the radiator drops, the resistance to coolant circulation decreases, and the pressure also decreases accordingly. In an embodiment of the present application, coolant pressure is introduced. On the basis of coolant leakage judgment based on duty cycle fluctuations or coolant pump speed changes, combined with coolant pressure changes, the duty cycle standard deviation greater than the standard deviation threshold or the coolant pump speed error greater than the error threshold is used as the main condition for satisfying coolant leakage, and the coolant pressure is used as an auxiliary judgment parameter for coolant leakage to determine whether the coolant is leaking. This multi-parameter comprehensive judgment method can improve the accuracy of coolant leakage monitoring and reduce the missed detection and false detection rates.

[0021] In conjunction with the first aspect, in certain implementations of the first aspect, a method for determining whether coolant is leaking based on coolant pressure is: Determine whether the coolant pressure is less than the coolant pressure threshold; If the coolant pressure is less than the coolant pressure threshold and lasts for a second set time, it is determined that the coolant is leaking; otherwise, it is determined that there is no coolant leakage.

[0022] In this embodiment, the coolant pressure is set to be less than the coolant pressure threshold and last for a second set time as the coolant leakage condition. By setting the coolant pressure threshold and duration, a dual judgment mechanism based on pressure and time is established to avoid misjudgments caused by short-term pressure fluctuations or accidental factors, thereby improving the accuracy of coolant leakage detection.

[0023] In conjunction with the first aspect, in certain implementations of the first aspect, the state parameter further includes a cooling system temperature, and the monitoring method further includes: In at least two consecutive preset time periods, if the duty cycle standard deviation is greater than the standard deviation threshold or the coolant pump speed error is greater than the error threshold, it is determined whether the coolant is leaking according to the cooling system temperature.

[0024] The overall temperature state of the cooling system needs to be maintained at 80-90°C through coolant circulation and radiator heat dissipation. When a coolant leak occurs in the cooling system, the amount of coolant is reduced, and the insufficient coolant flow makes it impossible to fill the entire cooling system. The heat generated by the engine cannot be effectively absorbed or dissipated, and the overall cooling system temperature will rise accordingly. The cooling system temperature refers to the comprehensive temperature state of the entire cooling system during operation, reflecting the heat transfer and dissipation of the entire cooling system during operation. In the embodiment of the present application, the cooling system temperature is introduced. On the basis of judging the coolant leakage based on the duty cycle fluctuation or the change in the coolant pump speed, combined with the cooling system temperature change, the duty cycle standard deviation greater than the standard deviation threshold or the coolant pump speed error greater than the error threshold is used as the main condition for satisfying the coolant leakage, and the cooling system temperature is used as an auxiliary judgment parameter for coolant leakage to judge whether the coolant is leaking. This multi-parameter comprehensive judgment method can improve the accuracy of coolant leakage monitoring and reduce the missed detection and false detection rates.

[0025] In conjunction with the first aspect, in certain implementations of the first aspect, a method for determining whether coolant is leaking based on the cooling system temperature is: determining whether the cooling system temperature is greater than a cooling system temperature threshold; If the cooling system temperature is greater than the cooling system temperature threshold and lasts for a third set time, it is determined that the coolant is leaking; otherwise, it is determined that there is no coolant leakage.

[0026] In this embodiment, a cooling system temperature exceeding a cooling system temperature threshold for a third set time period is considered a coolant leak condition. By setting both the cooling system temperature threshold and the duration, a dual-judgment mechanism based on both cooling system temperature and time is established, avoiding misjudgments due to short-term cooling system temperature fluctuations or accidental factors, and improving the accuracy of coolant leak detection.

[0027] In conjunction with the first aspect, in certain implementations of the first aspect, the state parameter further includes an ambient temperature of the cooling system, and the monitoring method further includes: In at least two consecutive preset time periods, if the duty cycle standard deviation is greater than the standard deviation threshold or the coolant pump speed error is greater than the error threshold, it is determined whether the coolant is leaking according to the ambient temperature of the cooling system.

[0028] There is a mutually influencing relationship between the ambient temperature of the cooling system (i.e., the temperature of the air surrounding the cooling system) and coolant leakage. A high temperature environment accelerates the aging and damage of cooling system components, leading to coolant leakage. Coolant leakage, in turn, can cause the engine to overheat, further increasing the ambient temperature of the cooling system and exacerbating component damage. In an embodiment of the present application, the ambient temperature of the cooling system is introduced. In addition to determining coolant leakage based on duty cycle fluctuations or changes in coolant pump speed, combined with changes in the ambient temperature of the cooling system, the duty cycle standard deviation being greater than the standard deviation threshold or the coolant pump speed error being greater than the error threshold is used as the primary condition for coolant leakage. The ambient temperature of the cooling system is used as an auxiliary judgment parameter for coolant leakage to determine whether the coolant is leaking. This multi-parameter comprehensive judgment method can improve the accuracy of coolant leakage monitoring and reduce missed detection and false detection rates.

[0029] In conjunction with the first aspect, in certain implementations of the first aspect, a method for determining whether coolant is leaking based on the ambient temperature of the cooling system is: Determining whether the ambient temperature of the cooling system is greater than an ambient temperature threshold; If the ambient temperature of the cooling system is greater than the ambient temperature threshold and lasts for a fourth set time, it is determined that the coolant is leaking; otherwise, it is determined that there is no coolant leakage.

[0030] In this embodiment of the present application, the cooling system's ambient temperature being greater than a threshold value for a fourth set time period is used as a coolant leakage condition. By setting both the threshold value and the duration, a dual judgment mechanism based on the cooling system's ambient temperature and time is established, thereby avoiding misjudgments due to short-term cooling system ambient temperature fluctuations or accidental factors, and improving the accuracy of coolant leak detection.

[0031] In combination with the first aspect, in certain implementations of the first aspect, the monitoring method further includes: when it is determined that the coolant is leaking, generating a warning signal and sending it to a user.

[0032] In the embodiments of the present application, when a coolant leak is detected, a warning signal is generated and sent to the user, allowing the user to be promptly notified of the coolant leak and to take timely countermeasures (e.g., simple repairs). This warning, on the one hand, prevents sudden mechanical failures (e.g., piston expansion and seizure due to engine overheating) during vehicle operation, which could cause loss of power and ensure vehicle safety. On the other hand, it prevents irreversible damage such as carbon deposits and cylinder scuffing caused by prolonged engine overheating, thereby extending the engine's service life, reducing the frequency of engine overhauls or replacements, and ultimately saving the user maintenance costs.

[0033] In a second aspect, a vehicle coolant leakage monitoring system is provided, which is applied to a vehicle. The system includes: A data acquisition module, configured to acquire in real time a coolant pump duty cycle sequence of a vehicle cooling system within a plurality of preset time periods; a calculation module, configured to calculate a duty cycle standard deviation of each preset time period based on a coolant pump duty cycle sequence; A first judgment module is configured to judge whether a standard deviation of the duty cycle in each preset time period is greater than a standard deviation threshold; The second judgment module judges whether the coolant leaks according to whether there are at least two consecutive preset time periods when the duty cycle standard deviation is greater than the standard deviation threshold in at least two preset time periods, and outputs the judgment result to the user.

[0034] In combination with the second aspect, in certain implementations of the second aspect, the data acquisition module is further used to acquire state parameters of the vehicle cooling system in real time within multiple preset time periods.

[0035] In combination with the second aspect, in certain implementations of the second aspect, the calculation module is further configured to: calculate a duty cycle change rate sequence based on the duty cycle sequence, and calculate the coolant pump speed error for each preset time period based on the actual coolant pump speed and the predicted coolant pump speed.

[0036] In combination with the second aspect, in some implementations of the second aspect, the system further includes a model building module, and the model building module is used to build a speed prediction model.

[0037] In combination with the second aspect, in certain implementations of the second aspect, the model building module is configured to: use the state parameters and PWM characteristic parameters of the vehicle cooling system as input features, and the predicted speed of the coolant pump as output features to build a speed prediction model.

[0038] In combination with the second aspect, in certain implementations of the second aspect, the data acquisition module is further used to acquire historical PWM characteristic parameter data and historical cooling system state parameter data.

[0039] In combination with the second aspect, in some implementations of the second aspect, the system further includes a model training module, which is used to train the speed prediction model.

[0040] In combination with the second aspect, in certain implementations of the second aspect, the system further includes a speed prediction module, which is configured to: obtain a predicted speed of the coolant pump through a speed prediction model based on the state parameters, the duty cycle sequence, and the duty cycle change rate sequence.

[0041] In combination with the second aspect, in some implementations of the second aspect, the first judgment module is further configured to: determine whether the coolant pump speed error in each preset time period is greater than an error threshold.

[0042] In combination with the second aspect, in certain implementations of the second aspect, the second judgment module is further configured to: when the coolant pump speed error is greater than the error threshold in at least two preset time periods, determine whether the coolant is leaking based on whether there are at least two consecutive preset time periods.

[0043] In combination with the second aspect, in certain implementations of the second aspect, the second judgment module is further configured to: when the duty cycle standard deviation is greater than the standard deviation threshold or the coolant pump speed error is greater than the error threshold within at least two consecutive preset time periods, determine whether the coolant is leaking based on the coolant temperature.

[0044] In combination with the second aspect, in certain implementations of the second aspect, the second judgment module is further configured to: within at least two consecutive preset time periods, if the duty cycle standard deviation is greater than the standard deviation threshold or the coolant pump speed error is greater than the error threshold, determine whether the coolant is leaking based on the coolant pressure.

[0045] In combination with the second aspect, in certain implementations of the second aspect, the second judgment module is further configured to: within at least two consecutive preset time periods, if the duty cycle standard deviation is greater than the standard deviation threshold or the coolant pump speed error is greater than the error threshold, determine whether the coolant is leaking based on the cooling system temperature.

[0046] In combination with the second aspect, in certain implementations of the second aspect, the second judgment module is further configured to: within at least two consecutive preset time periods, if the duty cycle standard deviation is greater than the standard deviation threshold or the coolant pump speed error is greater than the error threshold, determine whether the coolant is leaking based on the ambient temperature of the cooling system.

[0047] In combination with the second aspect, in certain implementations of the second aspect, the system further includes a control module, and the control module is configured to generate a warning signal and send it to a user when a coolant leak is determined.

[0048] In a third aspect, a computer program product is provided, comprising: a computer program code, which, when executed on a computer, causes the computer to execute the vehicle coolant leakage monitoring method according to the first aspect.

[0049] In a fourth aspect, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores computer program code, and the computer program code is executed by one or more processors. When the computer program code runs on the processor, the device including the one or more processors executes the vehicle coolant leakage monitoring method of the first aspect mentioned above.

[0050] In a fifth aspect, an embodiment of the present application provides a chip system, which includes a processor for calling a computer program or computer instructions stored in a memory so that the processor executes the vehicle coolant leakage monitoring method of the first aspect above.

[0051] In a sixth aspect, an embodiment of the present application provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the electronic device implements the vehicle coolant leakage monitoring method of the first aspect.

[0052] In a seventh aspect, a vehicle is provided. The vehicle includes the vehicle coolant leakage monitoring system described in the second aspect, or the computer-readable storage medium described in the fourth aspect, or the chip system described in the fifth aspect, or the electronic device described in the sixth aspect.

[0053] The beneficial effects of the technical solutions provided in the embodiments of the present application include at least: The vehicle coolant leak monitoring method and system provided in embodiments of the present application are applicable to vehicles. Based on changes in duty cycle, the system calculates the standard deviation of the duty cycle within each preset time period by acquiring a real-time sequence of the vehicle cooling system's coolant pump duty cycles over multiple preset time periods. A duty cycle standard deviation greater than a standard deviation threshold is used as a first necessary condition for coolant leakage, and a second necessary condition for coolant leakage is used to determine if the coolant has leaked. By determining coolant leakage based on duty cycle and time, the present embodiment enables real-time, accurate, and continuous monitoring of coolant leaks in the cooling system, effectively preventing missed detections and false detections. This addresses the inability of traditional methods to achieve real-time, accurate, and continuous monitoring of coolant leaks. The present embodiment also combines duty cycle with multiple parameters, including coolant pump speed, temperature (coolant temperature, cooling system temperature, and cooling system ambient temperature), and coolant pressure, for comprehensive assessment. This improves the accuracy of coolant leak monitoring and reduces missed detections and false detection rates.

[0054] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0056] Figure 1 This is a flow chart of a vehicle coolant leakage monitoring method according to an embodiment of the first aspect of the present application.

[0057] Figure 2 This is a flow chart of a method for determining whether coolant is leaking based on whether there are at least two consecutive preset time periods in an embodiment of the present application.

[0058] Figure 3 This is a flow chart of a vehicle coolant leakage monitoring method according to an embodiment of the second aspect of the present application.

[0059] Figure 4 This is a flow chart of a vehicle coolant leakage monitoring method according to an embodiment of the third aspect of the present application.

[0060] Figure 5 This is a flow chart of a method for determining whether coolant is leaking based on the coolant temperature according to an embodiment of the present application.

[0061] Figure 6 This is a flow chart of a vehicle coolant leakage monitoring method according to the fourth embodiment of the present application.

[0062] Figure 7 This is a flow chart of a vehicle coolant leakage monitoring method according to the fifth embodiment of the present application.

[0063] Figure 8 This is a flow chart of a method for determining whether coolant is leaking based on coolant pressure according to an embodiment of the present application.

[0064] Figure 9 This is a flow chart of a vehicle coolant leakage monitoring method according to the sixth embodiment of the present application.

[0065] Figure 10 This is a flow chart of a vehicle coolant leakage monitoring method according to the seventh embodiment of the present application.

[0066] Figure 11This is a flow chart of a method for determining whether coolant is leaking based on the cooling system temperature according to an embodiment of the present application.

[0067] Figure 12 This is a flow chart of a vehicle coolant leakage monitoring method according to an eighth embodiment of the present application.

[0068] Figure 13 This is a flow chart of a vehicle coolant leakage monitoring method according to the ninth embodiment of the present application.

[0069] Figure 14 This is a flow chart of a method for determining whether coolant is leaking based on the ambient temperature of the cooling system according to an embodiment of the present application.

[0070] Figure 15 This is a flow chart of a vehicle coolant leakage monitoring method according to the tenth embodiment of the present application.

[0071] Figure 16 This is a schematic diagram of the architecture of a vehicle coolant leakage monitoring system according to an embodiment of the present application.

[0072] Figure 17 This is a schematic diagram of the vehicle architecture of an embodiment of the present application.

[0073] In the figure, 100 is a vehicle coolant leakage monitoring system, 101 is a data acquisition module, 102 is a calculation module, 103 is a first judgment module, 104 is a second judgment module, 105 is a model building module, 106 is a model training module, 107 is a speed prediction module, 108 is a control module, 200 is a vehicle, 201 is a memory, 202 is a processor, and 203 is a computer program. DETAILED DESCRIPTION

[0074] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application more clearly understood, this application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0075] In the embodiments of the present application, prefixes such as "first" and "second" are used only to distinguish different description objects and have no limiting effect on the position, order, priority, quantity or content of the described objects. The use of prefixes such as ordinal numbers to distinguish description objects in the embodiments of the present application does not constitute a restriction on the described objects. For the statement of the described objects, please refer to the description in the context of the claims or embodiments, and the use of such prefixes should not constitute an unnecessary restriction. In addition, in the description of this embodiment, unless otherwise specified, the meaning of "plurality" is two or more.

[0076] The following describes the technical solutions in the embodiments of the present application in conjunction with the accompanying drawings. In the description of the embodiments of the present application, unless otherwise specified, " / " represents "or." For example, A / B can represent A or B. "And / or" in this document is merely a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, or B exists alone.

[0077] In the several embodiments provided in the embodiments of the present application, it should be understood that the disclosed systems and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection of some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0078] In the automotive field, with the continuous upgrading and updating of automobile structures, the complexity of automobile engine structures continues to increase, and the types and number of engine failures increase accordingly. The automobile cooling system has become a key component to ensure the normal operation of the engine and power system.

[0079] Coolant leakage is a common problem in automotive cooling systems. Traditional methods for detecting coolant leaks rely primarily on regular maintenance and visual inspections, such as observing the coolant tank level and checking for leaks on the outside of the cooling system. However, these methods have several drawbacks: Inefficiency: Regular maintenance takes a lot of time and manpower, and it is impossible to monitor the status of the cooling system in real time.

[0080] High cost: Frequent inspection and maintenance increase the cost of vehicle use.

[0081] Difficulty in detecting problems in real time: Coolant leaks may have occurred between two inspections but could not be detected in time, leading to serious consequences such as engine overheating.

[0082] Reliance on human judgment: Traditional detection methods are highly dependent on the experience and skills of maintenance personnel, resulting in high rates of missed detection and false detection.

[0083] Lack of intelligent continuous monitoring: Traditional methods cannot achieve real-time and continuous monitoring of the cooling system status, let alone early warning of potential leakage problems.

[0084] In order to improve the shortcomings of the above-mentioned traditional methods, in recent years, odorant-based monitoring methods and temperature sensor-based monitoring methods are generally used to monitor coolant leakage.

[0085] Odor-based monitoring methods add an odorant to the coolant and equip it with a corresponding detection unit to detect leaks. If a coolant leak occurs, visual, auditory, and olfactory indications are provided. However, the addition of the odorant and the associated detection circuitry significantly increases vehicle development costs. Furthermore, the odorant may negatively impact the coolant's thermal conductivity, thus affecting the engine's overall thermal management. Furthermore, if a coolant leak occurs, the odor can linger in the vehicle for an extended period, severely impacting the user experience.

[0086] Temperature sensor-based detection methods monitor the engine coolant's maximum temperature to determine if a leak exists. This approach, on the one hand, only issues an alarm when the coolant temperature exceeds a set threshold, making it incapable of predicting even small coolant leaks. On the other hand, the coolant's maximum temperature is closely related to engine operating time. If the vehicle is used for short periods of time or has only a short mileage, a coolant leak may not be effectively detected.

[0087] In summary, it can be seen that the detection methods in the prior art cannot detect coolant leakage in real time, accurately and continuously.

[0088] Based on the above application scenario, an embodiment of the present application provides a vehicle coolant leakage monitoring method.

[0089] Figure 1 This is a schematic flow chart of a vehicle coolant leakage monitoring method provided in an embodiment of the first aspect of the present application. The method is applicable to a vehicle and includes the following steps.

[0090] S1. Acquire in real time a coolant pump duty cycle sequence of a vehicle cooling system within a plurality of preset time periods.

[0091] The duty cycle refers to the ratio of the high-level time of the pulse signal to the total time of the entire cycle.

[0092] Duty cycle = high level time / total cycle time × 100% It's important to note that the duty cycle is an electrical signal that can be easily acquired and processed directly by hardware circuits (such as an ECU or PWM controller) without the need for complex additional mechanical devices or sensors. Duty cycle detection doesn't require direct contact with the coolant. This avoids corrosion and wear caused by coolant contact, extending the lifespan and reliability of the hardware circuits. Furthermore, it doesn't interfere with the structure and operation of the cooling system, ensuring its proper functioning.

[0093] In one embodiment of the present application, duty cycle data is collected at a fixed frequency (eg, 20 Hz) to form a duty cycle sequence.

[0094] S2. Calculate the duty cycle standard deviation of each preset time period based on the coolant pump duty cycle sequence.

[0095] The duty cycle standard deviation is a statistic that measures the dispersion of a set of duty cycle data. It represents the square root of the average of the squares of the deviations between each duty cycle data point and the average duty cycle. A larger standard deviation indicates greater data volatility; a smaller standard deviation indicates more concentrated data.

[0096] In one embodiment of the present application, a method for calculating the duty cycle standard deviation of each preset time period based on the coolant pump duty cycle sequence is as follows: Assume that there is a duty cycle sequence within a preset time period , N represents the total number of duty cycles; Calculate the average duty cycle;

[0097] Where, is the average duty cycle, For the duty cycle; Calculate the square of the deviation of each duty cycle from the average duty cycle; Calculate the average of the squared deviations to get the duty cycle variance;

[0098] Where Var is the duty cycle variance; Calculate the duty cycle standard deviation based on the duty cycle variance;

[0099] Where, is the duty cycle variance.

[0100] For example, in a certain automobile cooling system, within a certain preset time period, the duty cycle sequence data is as follows: 30%, 32%, 31%, 33%, 30%, 32%, 31%. First, normalize to the interval [0, 100] as follows: 0.30, 0.32, 0.31, 0.33, 0.30, 0.32, 0.31.

[0101] Calculate the average duty cycle;

[0102] Calculate the square of the deviation of each duty cycle from the average duty cycle;

[0103]

[0104]

[0105]

[0106]

[0107]

[0108]

[0109] Calculate the average of the squared deviations to get the duty cycle variance;

[0110] Calculate the duty cycle standard deviation based on the duty cycle variance;

[0111] From this result, we can see that the standard deviation of this set of duty cycle data is 1.15%, indicating that the fluctuation of the duty cycle is small.

[0112] S3. Determine whether the duty cycle standard deviation in each preset time period is greater than a standard deviation threshold.

[0113] It should be noted that the standard deviation threshold can be set according to actual conditions. For example, if the standard deviation threshold is set to 0.15, if the standard deviation of the duty cycle in a preset time period is 0.10, it means that the duty cycle in the preset time period is within the normal fluctuation range. If the standard deviation of the duty cycle in the preset time period is 0.16, it means that the duty cycle in the preset time period is not within the normal fluctuation range and may be abnormal.

[0114] S4. When the duty cycle standard deviation is greater than the standard deviation threshold in at least two preset time periods, determine whether the coolant is leaking based on whether there are at least two consecutive preset time periods.

[0115] In an embodiment of the present application, based on duty cycle fluctuations, the duty cycle standard deviation within each preset time period is calculated by acquiring a real-time sequence of the vehicle cooling system's coolant pump duty cycles within multiple preset time periods. A duty cycle standard deviation greater than a standard deviation threshold is used as the first necessary condition for coolant leakage, and a second necessary condition for coolant leakage is used to determine if a coolant leak has occurred. This method of monitoring the coolant pump's duty cycle changes can detect anomalies even when the leakage is minimal, quickly and accurately capturing early signs of a coolant leak and issuing a timely alarm, allowing the user to take action to prevent the leakage problem from further deteriorating. This allows maintenance work to be performed before the leakage problem worsens, thereby protecting the engine from high-temperature damage and effectively extending the vehicle's service life.

[0116] In one embodiment of the present application, see Figure 2 The method for determining whether the coolant is leaking is as follows: S41, determining whether there are at least two consecutive preset time periods; S42: If there are at least two consecutive preset time periods, it is determined that there is a coolant leak; otherwise, it is determined that there is no coolant leak.

[0117] In an embodiment of the present application, based on a multiple time window voting method, by satisfying the leakage condition (i.e., the duty cycle standard deviation is greater than the standard deviation threshold or the coolant pump speed error is greater than the error threshold) for multiple consecutive preset time periods (i.e., time windows), false detections are effectively reduced and the accuracy of coolant leakage monitoring is improved.

[0118] In one embodiment of the present application, the monitoring method further includes: when it is determined that the coolant is leaking, generating a warning signal and sending it to a user.

[0119] In an embodiment of the present application, when a coolant leak is determined, an early warning signal is generated and sent to the user, so that the user can be informed of the coolant leak in a timely manner so as to take timely countermeasures (for example, simple repairs, etc.).

[0120] For example, a sequence of duty cycles of the coolant pump of the vehicle cooling system for five consecutive preset time periods is obtained. Based on the coolant pump duty cycle sequence, the standard deviation of the duty cycle for each preset time period is calculated. The calculated standard deviations for the five preset time periods are 0.16, 0.14, 0.17, 0.16, and 0.155, respectively. A standard deviation threshold is set at 0.15. By comparing the calculated standard deviations of the duty cycle for the five preset time periods with the set standard deviation threshold, it is determined that the standard deviations of the duty cycles for the first, third, fourth, and fifth preset time periods are greater than the standard deviation threshold. Because the third, fourth, and fifth preset time periods are consecutive, a coolant leak is determined, and a warning signal is generated and sent to the user.

[0121] For example, a sequence of coolant pump duty cycles for the vehicle cooling system is obtained for five consecutive preset time periods. Based on the coolant pump duty cycle sequence, the standard deviation of the duty cycle for each preset time period is calculated. The calculated standard deviations for the five preset time periods are 0.12, 0.14, 0.17, 0.10, and 0.155, respectively. A standard deviation threshold is set at 0.15. By comparing the calculated standard deviations for the five preset time periods with the set standard deviation threshold, it is determined that the standard deviations for the duty cycles for the third and fifth preset time periods are greater than the standard deviation threshold. Since the third and fifth preset time periods are non-consecutive time periods, it is determined that there is no coolant leak, and monitoring continues.

[0122] Figure 3 This is a schematic flow chart of a vehicle coolant leakage monitoring method provided in an embodiment of the second aspect of the present application. The method is applicable to a vehicle and includes the following steps.

[0123] S1. Real-time acquisition of a coolant pump duty cycle sequence and state parameters of the vehicle cooling system within a plurality of preset time periods. The state parameters include actual coolant pump speed, coolant temperature, and coolant pressure.

[0124] S2. Calculate a duty cycle change rate sequence according to the duty cycle sequence.

[0125] In one embodiment of the present application, a method for calculating a duty cycle change rate sequence based on the duty cycle sequence is: Assume that there is a duty cycle sequence , N represents the total number of duty cycles; Set the time interval (e.g. 1 second) and calculate the rate of change of adjacent time points;

[0126] Where, For the A point in time, is the time interval.

[0127] Arrange the change rates of all time points in sequence to form a duty cycle change rate sequence.

[0128] S3. Obtain a predicted speed of the coolant pump by using a speed prediction model according to the state parameters, the duty cycle sequence, and the duty cycle change rate sequence.

[0129] In one embodiment of the present application, the speed prediction model is constructed by using the vehicle cooling system's state parameters and PWM characteristic parameters as input features and the coolant pump's predicted speed as an output feature. The state parameters include coolant temperature, coolant pressure, and actual coolant pump speed. The PWM characteristic parameters include duty cycle and duty cycle change rate.

[0130] In one embodiment of the present application, a long short-term memory (LSTM) model is used as the base model for constructing a speed prediction model. The LSTM model is a special recurrent network unit that can capture the correlations in long time series of cooling system sensor data. Using the LSTM model as the base model can improve the speed prediction model's accuracy.

[0131] The coolant pump speed is proportional to the coolant pump duty cycle.

[0132]

[0133] Where, is the coolant pump speed, is the duty cycle-speed ratio coefficient (calibrated by experiment), is the current coolant pump duty cycle.

[0134] Specifically, the duty cycle-speed ratio coefficient is calibrated by experiment The method is: under constant temperature and constant pressure conditions, measure the coolant pump speed under different coolant pump duty cycles, and calibrate the duty cycle-speed ratio coefficient .

[0135] The coolant pump target speed (i.e., the coolant pump predicted speed) can be predicted based on the coolant pump duty cycle. Therefore, when constructing the speed prediction model, the duty cycle is used as one of the input features of the speed prediction model.

[0136] Coolant temperature affects the efficiency and viscous resistance of the coolant pump. For example, excessively high coolant temperature can reduce coolant pump efficiency and speed. Therefore, when building a speed prediction model, coolant temperature is included as one of the input features. Temperature compensation can be used to improve the accuracy of the speed prediction model's coolant pump speed prediction.

[0137]

[0138] Where, is the coolant pump speed after temperature compensation correction, is the temperature compensation coefficient, is the coolant temperature, is the reference temperature.

[0139] Coolant pressure reflects the load on the cooling system. For example, a coolant leak causing a pressure drop can reduce the load. Alternatively, excessive coolant pressure can increase the load, causing the actual coolant pump speed to fall below the predicted speed. Therefore, when building a speed prediction model, coolant pressure is included as one of the input features. By correcting for pressure load, the speed prediction model improves the accuracy of the coolant pump speed prediction.

[0140]

[0141] Where, The coolant pump speed corrected for the pressure load, is the pressure compensation coefficient, is the coolant pressure, is the reference pressure.

[0142] The duty cycle change rate affects the motor's response speed. For example, when rapidly adjusting the duty cycle, it's necessary to compensate for the coolant pump's dynamic inertia. Therefore, when building a speed prediction model, the duty cycle change rate is used as one of the input features. This dynamic compensation for the duty cycle change rate improves the speed prediction model's accuracy in predicting the coolant pump's speed.

[0143]

[0144] Where, is the coolant pump speed after dynamic compensation of duty cycle change rate, is the duty cycle change rate compensation coefficient, is the duty cycle change rate.

[0145] Specifically, the speed prediction model is expressed as:

[0146] Where, Predicts the speed for the coolant pump.

[0147] The predicted speed of the coolant pump can also be corrected according to the actual speed of the coolant pump to update the model parameters.

[0148] The speed prediction model after updating the model parameters is expressed as:

[0149] Where, is the actual speed of the coolant pump, is the feedback coefficient, and in the embodiment of the present application .

[0150] In one embodiment of the present application, the method for constructing the speed prediction model further includes: training the speed prediction model. The method for training the speed prediction model is: Acquire historical PWM characteristic parameter data and historical cooling system state parameter data of the vehicle cooling system as training samples; the historical PWM characteristic parameter data includes duty cycle and duty cycle change rate, and the historical cooling system state parameter data includes coolant temperature and coolant pressure; The speed prediction model is trained using training samples to obtain a trained speed prediction model.

[0151] In an embodiment of the present application, historical PWM characteristic parameter data of the vehicle cooling system and historical cooling system state parameter data are used as training samples. The speed prediction model is trained by using the training samples, which can significantly improve the prediction accuracy and generalization ability of the speed prediction model and achieve accurate prediction of the target speed of the coolant pump.

[0152] S4. Calculate the coolant pump speed error for each preset time period based on the actual coolant pump speed and the predicted coolant pump speed.

[0153] Specifically, the coolant pump speed error is the mean square deviation between the predicted coolant pump speed and the actual coolant pump speed.

[0154] S5. Determine whether the coolant pump speed error within each preset time period is greater than an error threshold.

[0155] S6. When the coolant pump speed error is greater than the error threshold within at least two preset time periods, determine whether the coolant is leaking based on whether there are at least two consecutive preset time periods.

[0156] In the embodiment of the present application, the method for determining whether the coolant has leaked based on whether there are at least two consecutive preset time periods is the same as the method described in the embodiment of the first aspect of the present application, and will not be repeated here.

[0157] In an embodiment of the present application, based on changes in the coolant pump speed, the actual coolant pump speed is monitored, combined with the coolant pump duty cycle, duty cycle change rate, coolant temperature, and coolant pressure, and a speed prediction model is used to predict the coolant pump speed. Based on the difference between the actual coolant pump speed and the predicted coolant pump speed (i.e., the coolant pump speed error), the coolant pump speed error is greater than an error threshold as a first necessary condition for coolant leakage. The second necessary condition for coolant leakage is determined as a result of the first necessary condition being met for at least two consecutive preset time periods. This method can detect anomalies when the coolant leakage is still small and issue an alarm in a timely manner, facilitating the user to take measures to prevent the leakage problem from further deteriorating. Maintenance work can be performed before the leakage problem worsens, thereby protecting the engine from high-temperature damage and effectively extending the service life of the entire vehicle.

[0158] Figure 4 This is a schematic flow chart of a vehicle coolant leak monitoring method provided in an embodiment of the third aspect of the present application. The method is applicable to a vehicle and includes the following steps.

[0159] S1. Real-time acquisition of a coolant pump duty cycle sequence and a coolant temperature of a vehicle cooling system within a plurality of preset time periods.

[0160] S2. Calculate the duty cycle standard deviation of each preset time period based on the coolant pump duty cycle sequence.

[0161] Specifically, the method for calculating the duty cycle standard deviation of each preset time period based on the coolant pump duty cycle sequence is the same as the embodiment of the first aspect of the present application.

[0162] S3. Determine whether the duty cycle standard deviation in each preset time period is greater than a standard deviation threshold.

[0163] S4. When the duty cycle standard deviation is greater than the standard deviation threshold in at least two preset time periods, determine whether there are at least two consecutive preset time periods.

[0164] Specifically, the method for determining whether there are at least two consecutive preset time periods is the same as the embodiment of the first aspect of the present application.

[0165] S5. When the duty cycle standard deviation is greater than the standard deviation threshold in at least two consecutive preset time periods, determine whether the coolant is leaking based on the coolant temperature.

[0166] In this embodiment, coolant temperature is introduced. In addition to determining coolant leaks based on duty cycle fluctuations, combined with coolant temperature variations, a duty cycle standard deviation greater than a standard deviation threshold is used as the primary condition for coolant leaks. Coolant temperature is then used as an auxiliary parameter to determine coolant leaks. This multi-parameter comprehensive judgment method can improve the accuracy of coolant leak monitoring and reduce missed detections and false detection rates.

[0167] In one embodiment of the application, see Figure 5 , the method to judge whether the coolant is leaking according to the coolant temperature is: S51, determining whether the coolant temperature is greater than a coolant temperature threshold; S52: If the coolant temperature is greater than the coolant temperature threshold and lasts for a first set time, it is determined that there is a coolant leak; otherwise, it is determined that there is no coolant leak.

[0168] Specifically, the first set time can be set according to actual needs.

[0169] In an embodiment of the present application, a coolant temperature exceeding a coolant temperature threshold and persisting for a first set time is considered a condition for a coolant leak. By setting the coolant temperature threshold and duration, a dual judgment mechanism based on coolant temperature and time is established to avoid misjudgments due to short-term coolant temperature fluctuations or accidental factors, thereby improving the accuracy of coolant leak monitoring. For example, when a vehicle accelerates or climbs a slope, the coolant temperature may rise briefly, but not for a long time. By setting a duration, this normal phenomenon can be avoided from being misjudged as a coolant leak.

[0170] Figure 6 This is a schematic flow chart of a vehicle coolant leakage monitoring method provided in an embodiment of the fourth aspect of the present application. The method is applicable to a vehicle and includes the following steps.

[0171] S1. Real-time acquisition of a coolant pump duty cycle sequence and state parameters of the vehicle cooling system within a plurality of preset time periods. The state parameters include actual coolant pump speed, coolant temperature, and coolant pressure.

[0172] S2. Calculate a duty cycle change rate sequence according to the duty cycle sequence.

[0173] Specifically, the method for calculating the duty cycle change rate sequence based on the duty cycle sequence is the same as the embodiment of the second aspect of the present application.

[0174] S3. Obtain a predicted speed of the coolant pump by using a speed prediction model according to the coolant temperature, the coolant pressure, the duty cycle sequence, and the duty cycle change rate sequence.

[0175] Specifically, the method for constructing the speed prediction model is the same as the embodiment of the second aspect of this application.

[0176] S4. Calculate the coolant pump speed error for each preset time period based on the actual coolant pump speed and the predicted coolant pump speed.

[0177] S5. Determine whether the coolant pump speed error within each preset time period is greater than an error threshold.

[0178] S6. When the coolant pump speed error is greater than the error threshold in at least two preset time periods, determine whether there are at least two consecutive preset time periods.

[0179] Specifically, the method for determining whether there are at least two consecutive preset time periods is the same as the embodiment of the first aspect of the present application.

[0180] S7. When the coolant pump speed error is greater than the error threshold in at least two consecutive preset time periods, determine whether the coolant is leaking based on the coolant temperature.

[0181] Specifically, the method for determining whether the coolant is leaking based on the coolant temperature is the same as the embodiment of the third aspect of the present application.

[0182] In this embodiment, the coolant temperature is introduced. Based on the coolant pump speed change, the coolant pump speed error is considered greater than the error threshold as the primary condition for coolant leakage. The coolant temperature is used as an auxiliary judgment parameter to determine whether the coolant is leaking. This multi-parameter comprehensive judgment method can improve the accuracy of coolant leak monitoring and reduce the rate of missed detection and false detection.

[0183] Figure 7 This is a schematic flow chart of a vehicle coolant leakage monitoring method provided in an embodiment of the fifth aspect of the present application. The method is applicable to a vehicle and includes the following steps.

[0184] S1. Real-time acquisition of a coolant pump duty cycle sequence and a coolant pressure of a vehicle cooling system within a plurality of preset time periods.

[0185] S2. Calculate the duty cycle standard deviation of each preset time period based on the coolant pump duty cycle sequence.

[0186] Specifically, the method for calculating the duty cycle standard deviation of each preset time period based on the coolant pump duty cycle sequence is the same as the embodiment of the first aspect of the present application.

[0187] S3. Determine whether the duty cycle standard deviation in each preset time period is greater than a standard deviation threshold.

[0188] S4. When the duty cycle standard deviation is greater than the standard deviation threshold in at least two preset time periods, determine whether there are at least two consecutive preset time periods.

[0189] Specifically, the method for determining whether there are at least two consecutive preset time periods is the same as the embodiment of the first aspect of the present application.

[0190] S5. When the duty cycle standard deviation is greater than the standard deviation threshold in at least two consecutive preset time periods, determine whether the coolant is leaking based on the coolant pressure.

[0191] In this embodiment, coolant pressure is introduced. Based on the duty cycle fluctuations for coolant leak detection, combined with coolant pressure changes, the duty cycle standard deviation greater than the standard deviation threshold is used as the primary condition for coolant leakage, and coolant pressure is used as an auxiliary judgment parameter to determine coolant leakage. This multi-parameter comprehensive judgment method can improve the accuracy of coolant leak detection and reduce the rate of missed detection and false detection.

[0192] In one embodiment of the application, see Figure 8 , the method to judge whether the coolant is leaking according to the coolant pressure is: S51: Determine whether the coolant pressure is less than a coolant pressure threshold.

[0193] S52: If the coolant pressure is less than the coolant pressure threshold and lasts for a second set time, it is determined that there is a coolant leak; otherwise, it is determined that there is no coolant leak.

[0194] Specifically, the second set time can be set according to actual needs.

[0195] In this embodiment, the coolant pressure is set to be less than the coolant pressure threshold and last for a second set time as the coolant leakage condition. By setting the coolant pressure threshold and duration, a dual judgment mechanism based on pressure and time is established to avoid misjudgments caused by short-term pressure fluctuations or accidental factors, thereby improving the accuracy of coolant leakage detection.

[0196] Figure 9 This is a schematic flow chart of a vehicle coolant leakage monitoring method provided in the sixth embodiment of the present application. The method is applicable to a vehicle and includes the following steps.

[0197] S1. Real-time acquisition of a coolant pump duty cycle sequence and state parameters of the vehicle cooling system within a plurality of preset time periods. The state parameters include actual coolant pump speed, coolant temperature, and coolant pressure.

[0198] S2. Calculate a duty cycle change rate sequence according to the duty cycle sequence.

[0199] Specifically, the method for calculating the duty cycle change rate sequence based on the duty cycle sequence is the same as the embodiment of the second aspect of the present application.

[0200] S3. Obtain a predicted speed of the coolant pump by using a speed prediction model according to the coolant temperature, the coolant pressure, the duty cycle sequence, and the duty cycle change rate sequence.

[0201] Specifically, the method for constructing the speed prediction model is the same as the embodiment of the second aspect of this application.

[0202] S4. Calculate the coolant pump speed error for each preset time period based on the actual coolant pump speed and the predicted coolant pump speed.

[0203] S5. Determine whether the coolant pump speed error within each preset time period is greater than an error threshold.

[0204] S6. When the coolant pump speed error is greater than the error threshold in at least two preset time periods, determine whether there are at least two consecutive preset time periods.

[0205] Specifically, the method for determining whether there are at least two consecutive preset time periods is the same as the embodiment of the first aspect of the present application.

[0206] S7. When the coolant pump speed error is greater than the error threshold in at least two consecutive preset time periods, determine whether the coolant is leaking based on the coolant pressure.

[0207] Specifically, the method for determining whether the coolant is leaking based on the coolant pressure is the same as the fifth embodiment of the present application.

[0208] In this embodiment, coolant pressure is introduced. Based on the coolant pump speed change, the coolant pump speed error is considered greater than the error threshold as the primary condition for coolant leakage, combined with the coolant pressure change. This multi-parameter comprehensive judgment method can improve the accuracy of coolant leak monitoring and reduce the rates of missed detection and false detection.

[0209] Figure 10 This is a schematic flow chart of a vehicle coolant leakage monitoring method provided in an embodiment of the fifth aspect of the present application. The method is applicable to a vehicle and includes the following steps.

[0210] S1. Real-time acquisition of a coolant pump duty cycle sequence and a cooling system temperature of a vehicle cooling system within a plurality of preset time periods.

[0211] S2. Calculate the duty cycle standard deviation of each preset time period based on the coolant pump duty cycle sequence.

[0212] Specifically, the method for calculating the duty cycle standard deviation of each preset time period based on the coolant pump duty cycle sequence is the same as the embodiment of the first aspect of the present application.

[0213] S3. Determine whether the duty cycle standard deviation in each preset time period is greater than a standard deviation threshold.

[0214] S4. When the duty cycle standard deviation is greater than the standard deviation threshold in at least two preset time periods, determine whether there are at least two consecutive preset time periods.

[0215] Specifically, the method for determining whether there are at least two consecutive preset time periods is the same as the embodiment of the first aspect of the present application.

[0216] S5. When the duty cycle standard deviation is greater than the standard deviation threshold in at least two consecutive preset time periods, determine whether the coolant is leaking based on the cooling system temperature.

[0217] In this embodiment, the cooling system temperature is introduced. Based on the duty cycle fluctuations for coolant leak detection, combined with the cooling system temperature changes, the duty cycle standard deviation greater than the standard deviation threshold is used as the primary condition for coolant leakage, and the cooling system temperature is used as an auxiliary judgment parameter to determine coolant leakage. This multi-parameter comprehensive judgment method can improve the accuracy of coolant leak detection and reduce the rates of missed detection and false detection.

[0218] In one embodiment of the application, see Figure 11 , the method to judge whether the coolant is leaking according to the cooling system temperature is: S51: Determine whether the cooling system temperature is greater than a cooling system temperature threshold.

[0219] S52: If the cooling system temperature is greater than the cooling system temperature threshold and lasts for a third set time, it is determined that there is a coolant leak; otherwise, it is determined that there is no coolant leak.

[0220] Specifically, the third set time can be set according to actual needs.

[0221] In this embodiment, a cooling system temperature exceeding a cooling system temperature threshold for a third set time period is considered a coolant leak condition. By setting both the cooling system temperature threshold and the duration, a dual-judgment mechanism based on both cooling system temperature and time is established, avoiding misjudgments due to short-term cooling system temperature fluctuations or accidental factors, and improving the accuracy of coolant leak detection.

[0222] Figure 12 This is a schematic flow chart of a vehicle coolant leakage monitoring method provided in an eighth embodiment of the present application. The method is applicable to a vehicle and includes the following steps.

[0223] S1. Real-time acquisition of a coolant pump duty cycle sequence and state parameters of the vehicle cooling system within a plurality of preset time periods. The state parameters include actual coolant pump speed, coolant temperature, coolant pressure, and cooling system temperature.

[0224] S2. Calculate a duty cycle change rate sequence according to the duty cycle sequence.

[0225] Specifically, the method for calculating the duty cycle change rate sequence based on the duty cycle sequence is the same as the embodiment of the second aspect of the present application.

[0226] S3. Obtain a predicted speed of the coolant pump by using a speed prediction model according to the coolant temperature, the coolant pressure, the duty cycle sequence, and the duty cycle change rate sequence.

[0227] Specifically, the method for constructing the speed prediction model is the same as the embodiment of the second aspect of this application.

[0228] S4. Calculate the coolant pump speed error for each preset time period based on the actual coolant pump speed and the predicted coolant pump speed.

[0229] S5. Determine whether the coolant pump speed error within each preset time period is greater than an error threshold.

[0230] S6. When the coolant pump speed error is greater than the error threshold in at least two preset time periods, determine whether there are at least two consecutive preset time periods.

[0231] Specifically, the method for determining whether there are at least two consecutive preset time periods is the same as the embodiment of the first aspect of the present application.

[0232] S7. When the coolant pump speed error is greater than the error threshold in at least two consecutive preset time periods, determine whether the coolant is leaking based on the cooling system temperature.

[0233] Specifically, the method for determining whether the coolant is leaking based on the cooling system temperature is the same as the seventh embodiment of the present application.

[0234] In the embodiment of the present application, the cooling system temperature is introduced. On the basis of the coolant leakage judgment based on the change of the coolant pump speed, combined with the change of the cooling system temperature, the coolant pump speed error is greater than the error threshold as the main condition for satisfying the coolant leakage, and the cooling system temperature is used as an auxiliary judgment parameter for coolant leakage to judge whether the coolant is leaking. This multi-parameter comprehensive judgment method can improve the accuracy of coolant leakage monitoring and reduce the missed detection and false detection rates.

[0235] Figure 13This is a schematic flow chart of a vehicle coolant leakage monitoring method provided in the ninth embodiment of the present application. The method is applicable to a vehicle. The method includes the following steps.

[0236] S1. Real-time acquisition of a coolant pump duty cycle sequence of a vehicle cooling system and an ambient temperature of the cooling system within a plurality of preset time periods.

[0237] S2. Calculate the duty cycle standard deviation of each preset time period based on the coolant pump duty cycle sequence.

[0238] Specifically, the method for calculating the duty cycle standard deviation of each preset time period based on the coolant pump duty cycle sequence is the same as the embodiment of the first aspect of the present application.

[0239] S3. Determine whether the duty cycle standard deviation in each preset time period is greater than a standard deviation threshold.

[0240] S4. When the duty cycle standard deviation is greater than the standard deviation threshold in at least two preset time periods, determine whether there are at least two consecutive preset time periods.

[0241] Specifically, the method for determining whether there are at least two consecutive preset time periods is the same as the embodiment of the first aspect of the present application.

[0242] S5. When the duty cycle standard deviation is greater than the standard deviation threshold in at least two consecutive preset time periods, determine whether the coolant is leaking based on the ambient temperature of the cooling system.

[0243] In this embodiment, the cooling system's ambient temperature is incorporated into the coolant leak detection system. In addition to the duty cycle fluctuations used to determine coolant leaks, the duty cycle standard deviation greater than the standard deviation threshold is used as the primary condition for coolant leaks, combined with the cooling system's ambient temperature variation. The ambient temperature is then used as a secondary parameter to determine coolant leaks. This multi-parameter comprehensive judgment method can improve the accuracy of coolant leak monitoring and reduce missed and false detection rates.

[0244] In one embodiment of the application, see Figure 14 The method to judge whether the coolant is leaking is as follows: S51: Determine whether the ambient temperature of the cooling system is greater than an ambient temperature threshold.

[0245] S52: If the ambient temperature of the cooling system is greater than the ambient temperature threshold and lasts for a fourth set time, it is determined that there is a coolant leak; otherwise, it is determined that there is no coolant leak.

[0246] In this embodiment of the present application, the cooling system's ambient temperature being greater than a threshold value for a fourth set time period is used as a coolant leakage condition. By setting both the threshold value and the duration, a dual judgment mechanism based on the cooling system's ambient temperature and time is established, thereby avoiding misjudgments due to short-term cooling system ambient temperature fluctuations or accidental factors, and improving the accuracy of coolant leak detection.

[0247] Figure 15 This is a schematic flow chart of a vehicle coolant leakage monitoring method provided in the tenth embodiment of the present application. The method is applicable to a vehicle. The method includes the following steps.

[0248] S1. Real-time acquisition of a coolant pump duty cycle sequence and state parameters of the vehicle cooling system within a plurality of preset time periods. The state parameters include actual coolant pump speed, coolant temperature, coolant pressure, and ambient temperature of the cooling system.

[0249] S2. Calculate a duty cycle change rate sequence according to the duty cycle sequence.

[0250] Specifically, the method for calculating the duty cycle change rate sequence based on the duty cycle sequence is the same as the embodiment of the second aspect of the present application.

[0251] S3. Obtain a predicted speed of the coolant pump by using a speed prediction model according to the coolant temperature, the coolant pressure, the duty cycle sequence, and the duty cycle change rate sequence.

[0252] Specifically, the method for constructing the speed prediction model is the same as the embodiment of the second aspect of this application.

[0253] S4. Calculate the coolant pump speed error for each preset time period based on the actual coolant pump speed and the predicted coolant pump speed.

[0254] S5. Determine whether the coolant pump speed error within each preset time period is greater than an error threshold.

[0255] S6. When the coolant pump speed error is greater than the error threshold in at least two preset time periods, determine whether there are at least two consecutive preset time periods.

[0256] Specifically, the method for determining whether there are at least two consecutive preset time periods is the same as the embodiment of the first aspect of the present application.

[0257] S7. When the coolant pump speed error is greater than the error threshold in at least two consecutive preset time periods, determine whether the coolant is leaking based on the ambient temperature of the cooling system.

[0258] Specifically, the method for determining whether the coolant is leaking based on the ambient temperature of the cooling system is the same as the ninth embodiment of the present application.

[0259] In this embodiment, the cooling system's ambient temperature is introduced. Based on the coolant pump speed change, the coolant leak is determined based on the coolant pump speed change. The coolant pump speed error is greater than the error threshold as the primary condition for coolant leakage, and the cooling system's ambient temperature is used as an auxiliary judgment parameter to determine coolant leakage. This multi-parameter comprehensive judgment method can improve the accuracy of coolant leak monitoring and reduce the rates of missed detection and false detection.

[0260] An embodiment of the present application provides a vehicle coolant leakage monitoring system, which is applicable to vehicles. Figure 16 Shown is a schematic structural diagram of the vehicle coolant leakage monitoring system.

[0261] The vehicle coolant leakage monitoring system 100 includes: The data acquisition module 101 is used to acquire in real time a coolant pump duty cycle sequence of a vehicle cooling system within a plurality of preset time periods; A calculation module 102 is configured to calculate a duty cycle standard deviation of each preset time period based on the coolant pump duty cycle sequence; The first judgment module 103 judges whether the duty cycle standard deviation in each preset time period is greater than a standard deviation threshold; The second judgment module 104 judges whether the coolant leaks according to whether there are at least two consecutive preset time periods when the duty cycle standard deviation is greater than the standard deviation threshold in at least two preset time periods, and outputs the judgment result to the user.

[0262] Continue to see Figure 16 In one embodiment of the present application, the data acquisition module 101 is further configured to acquire status parameters of the vehicle cooling system in real time within a plurality of preset time periods.

[0263] Continue to see Figure 16 In one embodiment of the present application, the calculation module 102 is further configured to: calculate a duty cycle change rate sequence according to the duty cycle sequence, and calculate a coolant pump speed error in each preset time period according to the actual coolant pump speed and the predicted coolant pump speed.

[0264] Continue to see Figure 16 In one embodiment of the present application, the system further includes a model building module 105, and the model building module 5 is used to build a speed prediction model.

[0265] Continue to see Figure 16 In one embodiment of the present application, the model building module 105 is configured to: use the state parameters and PWM characteristic parameters of the vehicle cooling system as input features, and use the predicted speed of the coolant pump as output features to build a speed prediction model.

[0266] In one embodiment of the present application, the data acquisition module 101 is further configured to acquire historical PWM characteristic parameter data and historical cooling system state parameter data.

[0267] Continue to see Figure 16 In one embodiment of the present application, the system further includes a model training module 106, and the model training module 106 is used to train the speed prediction model.

[0268] Continue to see Figure 16 In one embodiment of the present application, the system further includes a speed prediction module 107, and the speed prediction module 107 is configured to: obtain a predicted speed of the coolant pump through a speed prediction model based on the state parameters, the duty cycle sequence, and the duty cycle change rate sequence.

[0269] In one embodiment of the present application, the first determination module 103 is further configured to determine whether the coolant pump speed error within each preset time period is greater than an error threshold.

[0270] In one embodiment of the present application, the second judgment module 104 is further configured to: when the coolant pump speed error is greater than the error threshold in at least two preset time periods, determine whether the coolant is leaking based on whether there are at least two consecutive preset time periods.

[0271] In one embodiment of the present application, the second judgment module 104 is further configured to: determine whether the coolant is leaking according to the coolant temperature when the duty cycle standard deviation is greater than the standard deviation threshold or the coolant pump speed error is greater than the error threshold in at least two consecutive preset time periods.

[0272] In one embodiment of the present application, the second judgment module 104 is further configured to: determine whether the coolant is leaking based on the coolant pressure if the duty cycle standard deviation is greater than the standard deviation threshold or the coolant pump speed error is greater than the error threshold within at least two consecutive preset time periods.

[0273] In one embodiment of the present application, the second judgment module 104 is further configured to: determine whether the coolant is leaking according to the cooling system temperature if the duty cycle standard deviation is greater than a standard deviation threshold or the coolant pump speed error is greater than an error threshold within at least two consecutive preset time periods.

[0274] In one embodiment of the present application, the second judgment module 104 is further configured to: determine whether the coolant is leaking according to the ambient temperature of the cooling system if the duty cycle standard deviation is greater than a standard deviation threshold or the coolant pump speed error is greater than an error threshold within at least two consecutive preset time periods.

[0275] Continue to see Figure 16In one embodiment of the present application, the system further includes a control module 108, which is configured to generate a warning signal and send it to a user when a coolant leak is determined.

[0276] The present application also provides a computer program product, comprising computer program code, which, when executed on a computer, causes the computer to execute the vehicle coolant leakage monitoring method according to the above embodiment. The computer program can be installed in a vehicle system.

[0277] The present application also provides a computer-readable storage medium storing program code. The program code is executed by one or more processors. When the program code is executed on the processors, a device including the one or more processors executes the vehicle coolant leak monitoring method described in the above embodiments. The processors executing the computer-readable storage medium can be installed in a vehicle system.

[0278] It should be understood that when the modules or units described herein are implemented using software, they can be implemented in whole or in part in the form of a computer program product. A computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the processes or functions described in the embodiments of the present application are generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transferred from one computer-readable storage medium to another computer-readable storage medium. The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server or data center that includes one or more available media. The available medium can be a magnetic medium (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a solid-state drive (SSD)).

[0279] An embodiment of the present application provides a chip system, which includes a processor, or a chip system including a memory and a processor, configured to call a computer program or computer instructions stored in the memory so that the processor executes the vehicle coolant leak monitoring method involved in the above embodiment. The chip system can be a single chip or a chip module composed of multiple chips. The chip system can be installed in a vehicle system.

[0280] An embodiment of the present application provides an electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the electronic device implements the vehicle coolant leakage monitoring method described in the above embodiment. The electronic device can be installed in a vehicle system.

[0281] An embodiment of the present application provides a vehicle.

[0282] For example, see Figure 17 The vehicle 200 includes a memory 201, a processor 202, and a computer program 203 stored in the memory 201 and executable on the processor 202. When the processor 202 executes the computer program 203, the processor 202 implements the vehicle coolant leakage monitoring method according to the above embodiment.

[0283] Exemplarily, the vehicle may include a data acquisition module, a calculation module, a first judgment module, and a second judgment module, and the data acquisition module, the calculation module, the first judgment module, and the second judgment module are integrated in a processor.

[0284] A data acquisition module, configured to acquire in real time a coolant pump duty cycle sequence of a vehicle cooling system within a plurality of preset time periods; a calculation module, configured to calculate a duty cycle standard deviation of each preset time period based on a coolant pump duty cycle sequence; A first judgment module is configured to judge whether a standard deviation of the duty cycle in each preset time period is greater than a standard deviation threshold; The second judgment module judges whether the coolant leaks according to whether there are at least two consecutive preset time periods when the duty cycle standard deviation is greater than the standard deviation threshold in at least two preset time periods, and outputs the judgment result to the user.

[0285] Those skilled in the art will appreciate that the modules, units, and method steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0286] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present application should be covered and fall within the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A vehicle coolant leakage monitoring method, characterized in that: Applied to a vehicle, the monitoring method includes: Real-time acquisition of a coolant pump duty cycle sequence of a vehicle cooling system within a plurality of consecutive preset time periods; Calculating a duty cycle standard deviation for each preset time period based on the coolant pump duty cycle sequence; Determine whether the duty cycle standard deviation in each preset time period is greater than a standard deviation threshold; When the duty cycle standard deviation is greater than the standard deviation threshold in at least two preset time periods, whether the coolant leaks is determined based on whether there are at least two consecutive preset time periods.

2. The vehicle coolant leakage monitoring method according to claim 1, characterized in that: The monitoring method further includes: judging whether the coolant is leaking according to the coolant pump speed error; the method for judging whether the coolant is leaking according to the coolant pump speed error is: Real-time acquisition of vehicle cooling system status parameters over multiple consecutive preset time periods; Calculating a duty cycle change rate sequence according to the duty cycle sequence; Obtaining a predicted speed of the coolant pump through a speed prediction model according to the state parameters, the duty cycle sequence, and the duty cycle change rate sequence; Calculating a coolant pump speed error for each preset time period based on the actual coolant pump speed and the predicted coolant pump speed; Determining whether the coolant pump speed error is greater than an error threshold within each preset time period; When the coolant pump speed error is greater than the error threshold in at least two preset time periods, it is determined whether the coolant is leaking based on whether there are at least two consecutive preset time periods.

3. The vehicle coolant leakage monitoring method according to claim 2, characterized in that: The speed prediction model is constructed by taking the state parameters and PWM characteristic parameters of the vehicle cooling system as input features and the predicted speed of the coolant pump as output features to construct the speed prediction model.

4. The vehicle coolant leakage monitoring method according to claim 3, wherein: The method for constructing the speed prediction model further includes: training the speed prediction model; the method for training the speed model is: Acquire historical PWM characteristic parameter data and historical cooling system state parameter data of the vehicle cooling system as training samples; the historical PWM characteristic parameter data includes duty cycle and duty cycle change rate; the historical cooling system state parameter data includes actual coolant pump speed, coolant temperature, and coolant pressure; The speed prediction model is trained using training samples to obtain a trained speed prediction model.

5. The vehicle coolant leakage monitoring method according to claim 2, wherein: The state parameter also includes coolant temperature; the monitoring method further includes: When the duty cycle standard deviation is greater than the standard deviation threshold or the coolant pump speed error is greater than the error threshold in at least two consecutive preset time periods, determining whether the coolant is leaking based on the coolant temperature; The method to judge whether the coolant is leaking according to the coolant temperature is: Determine whether the coolant temperature is greater than a coolant temperature threshold; If the coolant temperature is greater than the coolant temperature threshold and lasts for a first set time, it is determined that the coolant is leaking; otherwise, it is determined that there is no coolant leakage.

6. The vehicle coolant leakage monitoring method according to claim 2, wherein: The state parameter also includes coolant pressure; the monitoring method also includes: If, within at least two consecutive preset time periods, the duty cycle standard deviation is greater than a standard deviation threshold or the coolant pump speed error is greater than an error threshold, determining whether the coolant is leaking based on the coolant pressure; The method to judge whether the coolant is leaking according to the coolant pressure is: Determine whether the coolant pressure is less than the coolant pressure threshold; If the coolant pressure is less than the coolant pressure threshold and lasts for a second set time, it is determined that the coolant is leaking; otherwise, it is determined that there is no coolant leakage.

7. The vehicle coolant leakage monitoring method according to claim 2, wherein: The state parameter further includes the cooling system temperature, and the monitoring method further includes: In at least two consecutive preset time periods, if the duty cycle standard deviation is greater than a standard deviation threshold or the coolant pump speed error is greater than an error threshold, determining whether the coolant is leaking based on the cooling system temperature; The method to judge whether the coolant is leaking according to the cooling system temperature is: determining whether the cooling system temperature is greater than a cooling system temperature threshold; If the cooling system temperature is greater than the cooling system temperature threshold and lasts for a third set time, it is determined that the coolant is leaking; otherwise, it is determined that there is no coolant leakage.

8. The vehicle coolant leakage monitoring method according to claim 2, wherein: The state parameter further includes the ambient temperature of the cooling system, and the monitoring method further includes: In at least two consecutive preset time periods, if the duty cycle standard deviation is greater than a standard deviation threshold or the coolant pump speed error is greater than an error threshold, determining whether the coolant is leaking based on the ambient temperature of the cooling system; The method for judging whether the coolant is leaking according to the ambient temperature of the cooling system is: Determining whether the ambient temperature of the cooling system is greater than an ambient temperature threshold; If the ambient temperature of the cooling system is greater than the ambient temperature threshold and lasts for a fourth set time, it is determined that the coolant is leaking; otherwise, it is determined that there is no coolant leakage.

9. The vehicle coolant leakage monitoring method according to any one of claims 1 to 8, characterized in that: The monitoring method further includes: when it is determined that the coolant is leaking, generating an early warning signal and sending the signal to a user.

10. A vehicle coolant leakage monitoring system, characterized in that: Applied to vehicles, including: A data acquisition module, configured to acquire in real time a sequence of duty cycles of a coolant pump of a vehicle cooling system within a plurality of consecutive preset time periods; a calculation module, configured to calculate a duty cycle standard deviation of each preset time period based on a coolant pump duty cycle sequence; A first judgment module is configured to judge whether a standard deviation of the duty cycle in each preset time period is greater than a standard deviation threshold; The second judgment module judges whether the coolant leaks according to whether there are at least two consecutive preset time periods when the duty cycle standard deviation is greater than the standard deviation threshold in at least two preset time periods, and outputs the judgment result to the user.

Images