Method for detecting service life of air filter

Abstract

The invention discloses an air filter service life detection method. The method comprises the steps of detecting whether a current working condition meets an air filter detection function or not; if yes, air filtering detection judgment is started, and the current air inlet pressure and the current air inlet flow are obtained; air inlet resistance is determined according to the current air inlet pressure; a pre-calibrated service life detection model is obtained, wherein the service life detection model is a calibration relation model between the air inlet flow and the air inlet resistance; and according to the current air inlet flow, the air inlet resistance and the service life detection model, the current service life residual value of the air filter is determined. The air filter service life detection method provided by the invention can discriminate the current working condition of the air filter in time, and has the advantages of high accuracy, safety, reliability and the like.

Description

Technical Field

[0001] The invention relates to the technical field of vehicles, and in particular to a method for detecting the life of an air filter. Background Art

[0002] The air filter is installed in front of the engine air intake to filter dust particles, moisture and other substances in the air to prevent abnormal wear of the supercharger and the engine cylinder liner.

[0003] The air filter life detection method in the related art is to install an air filter blockage switch at the air filter outlet to perform a blockage alarm, but it only has a simple blockage alarm function and cannot realize functions such as air filter life warning. It has low accuracy and affects the safety of vehicle driving. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, one purpose of the present invention is to provide an air filter life detection method, which can timely judge the current working condition of the air filter and has the advantages of high accuracy, safety and reliability.

[0005] In order to achieve the above-mentioned purpose, the present invention proposes an air filter life detection method, including: detecting whether the current operating conditions meet the air filter detection function; if so, starting the air filter detection judgment, obtaining the current intake pressure and the current intake flow; determining the intake resistance according to the current intake pressure; obtaining a pre-calibrated life detection model, the life detection model is a calibrated relationship model between the intake flow and the intake resistance; determining the current remaining life value of the air filter according to the current intake flow, the intake resistance and the life detection model.

[0006] According to the air filter life detection method of the embodiment of the present invention, it can be determined whether the current working conditions are suitable for air filter life detection. Only when the conditions are met will the next step be entered, reducing the possibility of incorrect operation and misjudgment. The key data for air filter life detection is obtained by obtaining the intake pressure and intake flow. By collecting the current intake pressure and intake flow in real time, the working status and performance of the air filter can be accurately reflected. The intake resistance is calculated based on the current intake pressure to further understand the operating status of the air filter. The intake resistance is an important indicator of air filter contamination and blockage. By real-time monitoring and judgment, problems with the air filter can be discovered in time.

[0007] The intake resistance coordinates under the current intake flow rate are substituted into the life detection model. The model contains the relationship curve between intake flow rate and intake resistance at different life periods. The current remaining life value of the air filter is calculated. According to these parameters and certain logic judgment, the accuracy of the judgment result can be improved, and the safety and reliability of vehicle driving can be improved.

[0008] Therefore, the air filter life detection method according to the embodiment of the present invention can timely judge the current working condition of the air filter, and has the advantages of high accuracy, safety and reliability.

[0009] In some embodiments of the present invention, the detection of whether the current operating conditions satisfy the air filter detection function includes: obtaining the engine speed in real time, and judging whether condition a is satisfied: whether the fluctuation value of the speed of the engine in the idle condition is less than the speed fluctuation threshold; obtaining the engine intake flow in real time; judging whether condition b is satisfied: the fluctuation value of the intake flow of the engine in the idle condition is less than the intake volume fluctuation threshold; if the above conditions a and b are satisfied at the same time, and the first maintenance time is reached, then entering the air filter detection judgment.

[0010] In some embodiments of the present invention, the speed fluctuation threshold is 5 rpm, and the intake volume fluctuation threshold is 10 m 3 / h, and the first maintaining time is 5s.

[0011] In some embodiments of the present invention, the detection of whether the current operating conditions meet the air filter detection function includes: obtaining the engine intake flow in real time; judging whether condition c is met: the engine intake flow is between the maximum preset flow value and the minimum preset flow value; if condition c is met and the second maintenance time is reached, entering the air filter detection judgment.

[0012] In some embodiments of the present invention, the life detection model includes at least an original flow resistance curve and an end-of-life flow resistance curve; before determining the current remaining life value of the air filter according to the current intake flow, the intake resistance and the life detection model, it also includes: judging whether the air filter is in normal operating state; judging whether condition d is satisfied: whether the coordinates of the intake resistance under the current intake flow are higher than or equal to the original flow resistance curve; judging whether condition f is satisfied: whether the coordinates of the intake resistance under the current intake flow are lower than the end-of-life flow resistance curve; if the above conditions d and f are satisfied at the same time, then the air filter is in normal operating state.

[0013] In some embodiments of the present invention, it is determined whether condition d is satisfied: whether the coordinates of the intake resistance at the current intake flow rate are higher than the original flow resistance curve; if not, the air filter cannot play a filtering role; it is determined whether condition f is satisfied: whether the coordinates of the intake resistance at the current intake flow rate are lower than the end-of-life flow resistance curve; if not, the air filter reaches its maximum service life.

[0014] In some embodiments of the present invention, determining the current remaining life value of the air filter based on the current intake flow rate, the intake resistance and the life detection model includes: measuring the distance S1 between the coordinates of the intake resistance at the current intake flow rate and the original flow resistance curve; measuring the distance S2 between the coordinates of the intake resistance at the current intake flow rate and the end-of-life flow resistance curve; and calculating the current remaining life value of the air filter based on the distance S1 and the distance S2.

[0015] In some embodiments of the present invention, a signal of an alarm prompt level is issued according to the current remaining life value.

[0016] In some embodiments of the present invention, the signal of issuing an alarm prompt level based on the current remaining life value includes: determining whether the current remaining life value of the air filter is less than or equal to the first remaining life value; if so, issuing a first-level alarm prompt signal; determining whether the current remaining life value of the air filter is less than or equal to the second remaining life value; if so, issuing a second-level alarm prompt signal.

[0017] In some embodiments of the present invention, after issuing an alarm based on the current remaining life value, the current alarm level is stored until the current operating condition is detected again to determine whether it satisfies the air filter detection function.

[0018] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which: Figure 1 is a flow chart of an air filter life detection method according to an embodiment of the present invention; Figure 2 is a schematic diagram of an air filter life detection method according to an embodiment of the present invention; Figure 3 is a principle diagram of whether the air filter life detection method according to an embodiment of the present invention satisfies the air filter detection function; Figure 4 Schematic diagram of a life detection model of an air filter life detection method according to an embodiment of the present invention. DETAILED DESCRIPTION

[0020] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0021] In the description of the present invention, "first feature" or "second feature" may include one or more of the features.

[0022] In the description of the present invention, "plurality" means two or more than two, and "several" means one or more.

[0023] The following describes an air filter life detection method according to an embodiment of the present invention with reference to the accompanying drawings.

[0024] Check whether the current working conditions meet the air filter detection function; If yes, start air filter detection and judgment to obtain the current intake pressure and current intake flow; determining an intake resistance according to the current intake pressure; Acquire a pre-calibrated life detection model, where the life detection model is a calibration relationship model between intake flow rate and intake resistance; The current remaining life value of the air filter is determined according to the current intake flow rate, the intake resistance and the life detection model.

[0025] For example, the calibration relationship model between intake flow and intake resistance can be calibrated by the air filter at the initial life and the air filter at the end of life, or by adding an additional air filter under a unit life. The specific calibration process is as follows: a calibration experiment is performed using an original, unused air filter to obtain intake resistance under different intake preset flow rate values; a calibration experiment is performed on an air filter at the end of its service life to obtain intake resistance under different intake preset flow rate values. In this way, a relationship curve between intake flow and intake air flow resistance of an air filter at the initial life, and a relationship curve between intake flow and intake air flow resistance of an air filter at the end of its service life can be formed, based on the relationship curve between intake flow and intake air flow resistance at the initial life and at the end of its service life.

[0026] According to the air filter life detection method of the embodiment of the present invention, the key data for air filter life detection is obtained by obtaining the intake pressure and intake flow rate. It can be understood that the intake air flow resistance of the normally used air filter under the current intake air flow rate falls between the relationship curves of the air filter intake flow rate and intake air flow resistance at the initial life and the end of life. The closer the intake air flow resistance is to the relationship curve at the end of life, the closer it is to the service life; the closer the intake air flow resistance is to the initial life relationship curve, the larger the remaining value of the service life is.

[0027] By collecting the current intake pressure and intake flow in real time, the working status and performance of the air filter can be accurately reflected. The intake resistance is calculated based on the current intake pressure to further understand the operating status of the air filter. The intake resistance is an important indicator of air filter contamination and blockage. By real-time monitoring and judgment, air filter problems can be discovered in time.

[0028] The intake resistance coordinates under the current intake flow rate are substituted into the life detection model. The model contains the relationship curve between intake flow rate and intake resistance at different life periods. The current remaining life value of the air filter is calculated. According to these parameters and certain logic judgment, the accuracy of the judgment result can be improved, and the safety and reliability of vehicle driving can be improved.

[0029] Therefore, the air filter life detection method according to the embodiment of the present invention can timely judge the current working condition of the air filter, and has the advantages of high accuracy, safety and reliability.

[0030] In addition, if Figure 3 As shown, the vehicle system includes an engine, a controller, an air filter, a negative pressure sensor after the air filter, an instrument panel, and connecting pipes and wiring harnesses of each component.

[0031] Air enters the air filter from the air intake port and is filtered before entering the engine. Due to the resistance of the air filter itself and the dust and water content in the air filter, the air intake pressure at the rear end of the air filter is negative relative to the atmospheric pressure. The negative pressure sensor after the air filter is connected to the controller through wires. The controller supplies power to the sensor and obtains the feedback voltage of the sensor. Other engine signals such as speed and intake volume are transmitted to the controller through the wiring harness. The controller is connected to the instrument through the CAN signal to send information such as air filter life and alarms. The instrument displays the corresponding information to remind the driver to perform air filter maintenance.

[0032] Specifically, Figure 2 As shown, the detection of whether the current working condition meets the air filter detection function includes: The engine speed is obtained in real time to determine whether condition a is met: whether the fluctuation value of the engine speed under idle condition is lower than the speed fluctuation threshold. The engine intake flow is obtained in real time to determine whether condition b is met: the fluctuation value of the intake flow under idle condition is lower than the intake flow fluctuation threshold. The speed fluctuation threshold and the intake flow fluctuation threshold can be measured experimentally and set in advance.

[0033] If the above conditions a and b are met at the same time and the first maintenance time is reached, the air filter detection judgment is entered.

[0034] For example, first turn the vehicle key switch to the ON position, then the vehicle starts to power on. If the controller reads that the last driving state was normal, the controller will obtain the engine speed and engine intake flow in real time to determine whether condition a is met: whether the fluctuation value of the engine speed is lower than the speed fluctuation threshold. If condition a is met, it can continue to determine whether condition b is met: the engine intake flow fluctuation value is lower than the intake volume fluctuation threshold. If condition a is not met, the air filter detection judgment will not be entered.

[0035] If condition a is met: whether the fluctuation value of the engine speed is less than the speed fluctuation threshold, then it can be determined whether condition b is met: the engine intake flow fluctuation value is less than the intake volume fluctuation threshold. If condition b is not met, the air filter detection judgment will not be entered.

[0036] When both condition a and condition b are met, it is determined to enter the air filter detection judgment. When any one of condition a and condition b is not met, it is determined not to enter the air filter detection judgment, maintain the last alarm state, and do not update the state.

[0037] Those skilled in the art will appreciate that the present invention does not impose any specific limitation on the order of determining the above conditions a and b, that is, the order of detecting the engine speed and the engine intake air flow rate can be changed, and the order of conditions a and b for determining whether the system is abnormal can also be adjusted accordingly without affecting the accuracy of the system's judgment.

[0038] In some embodiments of the present invention, the speed fluctuation threshold is 5 rpm, and the intake volume fluctuation threshold is 10 m 3 / h, the first holding time is 5s.

[0039] Set the speed fluctuation threshold to 5rpm. When the engine speed fluctuation value is within this threshold, it can be considered that the engine state is relatively stable, thereby obtaining more reliable intake pressure and flow data to ensure the accuracy of subsequent life calculation. Set the intake volume fluctuation threshold to 10m 3 / h, and the detection is carried out within the intake volume fluctuation threshold, which can effectively improve the reliability of the detection system and avoid misjudgment and unnecessary maintenance caused by inaccurate instantaneous data. Setting a maintenance time of 5s can ensure that sufficient observation windows are provided during the detection to obtain stable measurement data, further improving the accuracy of air filter detection judgment.

[0040] In addition, detecting whether the current operating conditions meet the air filter detection function also includes: obtaining the engine intake flow in real time; judging whether condition c is met: the engine intake flow is between the maximum preset flow value and the minimum preset flow value; if condition c is met and the second maintenance time is reached, then entering the air filter detection judgment.

[0041] For example, first turn the vehicle key switch to the ON position, then the vehicle starts to power on, and determine whether condition c is met: the engine intake flow is between the maximum preset flow value and the minimum preset flow value. If condition c is met, it can be determined whether condition c is met and whether it continues within the second maintenance time. If both condition c and the second maintenance time are met, enter the air filter detection judgment. If neither condition c nor the second maintenance time is met, do not enter the air filter detection judgment.

[0042] In some specific embodiments of the present invention, Figure 4 As shown, the life detection model at least includes an original flow resistance curve and an end-of-life flow resistance curve. Before determining the current remaining life value of the air filter according to the current intake flow, the intake resistance and the life detection model, it also includes: judging whether the air filter is in a normal operating state. Judging whether condition d is satisfied: whether the coordinate of the intake resistance at the current intake flow is higher than or equal to the original flow resistance curve. Judging whether condition f is satisfied: whether the coordinate of the intake resistance at the current intake flow is lower than the end-of-life flow resistance curve. If the above conditions d and f are satisfied at the same time, then the air filter is in a normal operating state.

[0043] For example, when entering the air filter detection and judgment condition, the controller will read the voltage of the current pressure sensor and convert it into the current remaining life value based on the pressure curve and the end-of-life flow resistance curve. The remaining life value can be in percentage form or other common forms.

[0044] When entering the air filter detection judgment working condition, determine whether condition d is met: whether the coordinates of the intake resistance under the current intake flow rate are higher than or equal to the original flow resistance curve. If condition d is met, it can be determined whether condition f is met: whether the coordinates of the intake resistance under the current intake flow rate are lower than the end-of-life flow resistance curve.

[0045] If both condition d and condition f are met, the air filter is judged to be in the most normal operating state. If any one of condition d and condition f is not met, the air filter is judged to be in an abnormal state.

[0046] Those skilled in the art will appreciate that the present invention does not impose any specific limitation on the order of determining the above conditions d and f, that is, the order of detecting the intake resistance and the end-of-life flow resistance curve under the current intake flow rate can be changed, and the order of conditions d and f for determining whether the system is abnormal can also be adjusted accordingly without affecting the accuracy of the system's judgment.

[0047] In some embodiments of the present invention, it is determined whether condition d is satisfied: whether the coordinates of the intake resistance at the current intake flow rate are higher than the original flow resistance curve; if not, the air filter cannot play a filtering role; it is determined whether condition f is satisfied: whether the coordinates of the intake resistance at the current intake flow rate are lower than the end-of-life flow resistance curve; if not, the air filter reaches its maximum service life.

[0048] For example, Figure 4 As shown, the flow resistance curve at the end of life is Figure 4 The curve above, the original flow resistance curve is Figure 4 The curve below determines whether condition d is met: whether the coordinate of the intake resistance at the current intake flow rate is higher than the original flow resistance curve. If not, it indicates the area between the original flow resistance curve and the horizontal axis. At this time, the vehicle may not have an air filter installed or the air filter is a low-quality air filter, indicating that the air filter cannot play a filtering role. Determine whether condition f is met: whether the coordinate of the intake resistance at the current intake flow rate is lower than the end-of-life flow resistance curve. If not, it indicates the area between the end-of-life flow resistance curve and the vertical axis, indicating that the performance index of the air filter meets the maximum service life.

[0049] In some embodiments of the present invention, determining the current remaining life value of the air filter based on the current intake flow rate, the intake resistance and the life detection model includes: measuring the distance S1 between the coordinates of the intake resistance at the current intake flow rate and the original flow resistance curve; measuring the distance S2 between the coordinates of the intake resistance at the current intake flow rate and the end-of-life flow resistance curve; and calculating the current remaining life value of the air filter based on the distance S1 and the distance S2.

[0050] When condition d: whether the coordinates of the intake resistance at the current intake flow rate are higher than the original flow resistance curve and condition f: whether the coordinates of the intake resistance at the current intake flow rate are lower than the end-of-life flow resistance curve are both yes, it represents the area between the original flow resistance curve and the end-of-life flow resistance curve.

[0051] For example, the ratio of the service life to the service life that has not yet been used can be expressed as nS1:mS2, where n and m are proportional coefficients. When n=1 and m=1, the distances between S1 and S2 are equal, which means that the remaining value of the current life of the air filter is 50%. When S1 is higher than S2, it means that the remaining value of the current life of the air filter is less than 50%. When S1 is lower than S2, it means that the remaining value of the current life of the air filter is more than 50%.

[0052] In some embodiments of the present invention, the method further includes: sending a warning level signal according to the current remaining life value. For example, a dedicated indicator light is set on the dashboard of the vehicle, and when the current remaining life value of the air filter is lower than a threshold, the indicator light lights up (such as yellow or red) to remind the driver.

[0053] Relevant information can also be displayed on the dashboard or on-board display, such as "air filter needs to be replaced" or the current remaining life percentage. For example, a warning message "air filter remaining 30%" can be displayed. The driver can also be prompted by audio, such as a short alarm or beep to attract the driver's attention. It can be designed to be a "beep" sound or a continuous beep to remind the user to check and replace the air filter in time.

[0054] In some embodiments of the present invention, issuing a signal of an alarm prompt level according to the current remaining life value includes: determining whether the current remaining life value of the air filter is less than or equal to a first remaining life value; If so, a first-level alarm prompt signal is issued; Determine whether the current remaining life value of the air filter is less than or equal to the second remaining life value; If so, a secondary alarm prompt signal is issued.

[0055] Specifically, the remaining life value is calculated as a percentage. The first remaining life value can be set to 30%. When the air filter receives that the current remaining life value of the air filter is less than 30%, the vehicle system will issue a first-level alarm signal. The second remaining life value can be set to 10%. When the air filter receives that the current remaining life value of the air filter is less than 10%, the vehicle system will issue a second-level alarm prompt signal. We can distinguish between the first-level alarm prompt signal and the second-level alarm prompt signal by setting an alarm light or prompting specific alarm information. When the driver receives the alarm signal, it can be more convenient to make a judgment and perform subsequent operations.

[0056] In some embodiments of the present invention, after an alarm is issued according to the current remaining life value, the current alarm level is stored until the current operating condition is detected again to determine whether it satisfies the air filter detection function.

[0057] When the remaining value of the current air filter life drops to the preset alarm threshold, the vehicle system can issue an alarm prompt in time to remind the driver to check and replace the air filter in time, effectively avoiding the engine performance degradation caused by air filter failure. The air filter life detection method can store the current alarm prompt level and provide a historical record of the air filter status, so that users can better understand the use of the air filter.

[0058] When the controller receives the alarm prompt, it will re-check whether the current operating conditions meet the air filter detection performance to ensure the effectiveness and accuracy of the alarm and avoid repeated detection under inappropriate conditions.

[0059] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example.

[0060] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A method for detecting the life of an air filter, characterized in that: include: Check whether the current working conditions meet the air filter detection function; If yes, start air filter detection and judgment to obtain the current intake pressure and current intake flow; determining an intake resistance according to the current intake pressure; Acquire a pre-calibrated life detection model, where the life detection model is a calibration relationship model between intake flow rate and intake resistance; The current remaining life value of the air filter is determined according to the current intake flow rate, the intake resistance and the life detection model.

2. The air filter life detection method according to claim 1, characterized in that: The detection of whether the current working condition meets the air filter detection function includes: The engine speed is obtained in real time to determine whether condition a is met: whether the fluctuation value of the engine speed under the idle condition is less than the speed fluctuation threshold; The engine intake flow is obtained in real time to determine whether condition b is met: the intake flow fluctuation value when the engine is in an idle condition is less than the intake flow fluctuation threshold; If the above conditions a and b are met at the same time and the first maintenance time is reached, the air filter detection judgment is entered.

3. The air filter life detection method according to claim 2, characterized in that: The speed fluctuation threshold is 5 rpm, and the intake volume fluctuation threshold is 10 m 3 / h, and the first maintaining time is 5s.

4. The air filter life detection method according to claim 1, characterized in that: The detection of whether the current working condition meets the air filter detection function includes: Obtain the engine intake flow in real time; determine whether condition c is met: the engine intake flow is between the maximum preset flow value and the minimum preset flow value; If condition c is met and the second maintenance time is reached, the air filter detection judgment is entered.

5. The air filter life detection method according to claim 1, characterized in that: The life detection model at least includes an original flow resistance curve and an end-of-life flow resistance curve; Before determining the current remaining life value of the air filter according to the current intake flow rate, the intake resistance and the life detection model, the method further includes: Determine whether the air filter is in normal operation; Determine whether condition d is satisfied: whether the coordinate of the intake resistance under the current intake flow rate is higher than or equal to the original flow resistance curve; Determine whether condition f is satisfied: whether the coordinate of the intake resistance at the current intake flow rate is lower than the end-of-life flow resistance curve; If the above conditions d and f are met at the same time, the air filter is in normal operation.

6. The air filter life detection method according to claim 5, characterized in that: Determine whether condition d is satisfied: whether the coordinate of the intake resistance under the current intake flow rate is higher than the original flow resistance curve; If not, the air filter cannot play a filtering role; Determine whether condition f is satisfied: whether the coordinate of the intake resistance at the current intake flow rate is lower than the end-of-life flow resistance curve; If not, the air filter has reached its maximum service life.

7. The air filter life detection method according to claim 5, characterized in that: Determining the current remaining life value of the air filter according to the current intake flow, the intake resistance and the life detection model includes: Measure the distance S1 between the coordinates of the intake resistance at the current intake flow rate and the original flow resistance curve; Measure the distance S2 between the coordinates of the intake resistance at the current intake flow rate and the flow resistance curve at the end of life; The current remaining life value of the air filter is calculated according to the distance S1 and the distance S2.

8. The air filter life detection method according to claim 7, characterized in that: Also includes: An alarm level signal is issued according to the current remaining life value.

9. The air filter life detection method according to claim 8, characterized in that: The signal of issuing an alarm prompt level according to the current remaining life value includes: Determining whether the current remaining life value of the air filter is less than or equal to a first remaining life value; If so, a first-level alarm prompt signal is issued; Determining whether the current remaining life value of the air filter is less than or equal to a second remaining life value; If so, a secondary alarm prompt signal is issued.

10. The air filter life detection method according to claim 8, characterized in that: After issuing an alarm prompt according to the current remaining life value, the current alarm prompt level is stored until the current operating condition is detected again to determine whether it satisfies the air filter detection function.

Images