Strategy method for preventing false alarm in urea quality sensor detection

Abstract

The invention relates to a strategy method for preventing false alarm through urea quality sensor detection, which comprises the following steps of: performing state detection after electrification, then distinguishing a bubble state from a non-bubble state, performing bubble scraping on the bubble state, entering the non-bubble state, and distinguishing a liquid adding working condition, a concentration sudden change, a vehicle running condition and a conventional working condition. Then the detection probe performs floating detection, compares historical data with current data of the urea sensor, distinguishes and recognizes abnormal working conditions, sends correct numerical values according to working condition types, and performs bubble scraping by using a dense brush; the urea concentration at different heights can be detected through probe floating, and the technical problems that in the prior art, the accurate urea concentration in the vehicle running process cannot be mastered in real time, and the urea concentration misinformation situation caused by temperature change of vehicle running for a long time cannot be coped with are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle engines, and in particular to a strategy method for preventing false alarms in urea quality sensor detection. Background Art

[0002] The National VI regulations require the use of urea concentration sensors to monitor the actual urea concentration. Adding unqualified urea will cause a fault to be reported and torque and speed to be limited. The mainstream urea concentration sensors on the market are based on the ultrasonic principle, relying on the physical phenomenon of different transmission speeds of ultrasound in liquids of different concentrations to measure the concentration value. When adding urea and the vehicle is bumpy, bubbles may be generated in the urea. If the bubbles enter the ultrasonic detection area, the urea concentration measurement will be abnormal, and the urea concentration abnormality fault will be falsely reported.

[0003] Patent No. CN202310622315.9 discloses a method, device, equipment and storage medium to avoid abnormal urea concentration false alarms. When the controller is powered on or the vehicle is filled with urea during power-on, the urea concentration within a set time is pre-detected, and before the pre-detection is completed, the abnormal urea concentration fault diagnosis is frozen; if the pre-detected urea concentration is unqualified, the abnormal urea concentration fault diagnosis continues to be frozen, and the urea concentration is detected again after the vehicle mileage reaches the set value; if the re-detected urea concentration is qualified, the qualified urea concentration is locked and the fault diagnosis is performed. This application can pre-treat the urea concentration and effectively avoid abnormal urea concentration fault false alarms, but this method has the following problems: first, it cannot control the urea concentration during vehicle driving in real time; second, simple pre-treatment cannot deal with the false alarm caused by bubbles generated during vehicle operation, nor can it deal with the false alarm of urea concentration caused by temperature changes during long-term driving of the vehicle. The whole method is too one-sided, and the methods for dealing with various situations are not comprehensive. Summary of the invention

[0004] The purpose of the present invention is to address the deficiencies of the prior art. By comparing the historical data of the urea sensor with the current data, the abnormal operating conditions are distinguished and identified, and the correct value is sent according to the operating condition category. In addition, a dense brush is used to scrape off bubbles, and the urea concentration at different heights can be detected by floating the probe, so as to solve the technical problems in the prior art that the precise urea concentration during vehicle driving cannot be controlled in real time, and the false alarm of urea concentration caused by temperature changes during long-term vehicle driving is unable to be dealt with.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A strategy method for preventing false alarms in urea quality sensor detection includes steps S1: starting with power on;

[0007] Step S2: state detection;

[0008] Step S3: Bubble state or non-bubble state;

[0009] Step S4: scraping off bubbles in the bubble state, and then entering the non-bubble state;

[0010] Step S5: If bubbles still exist after the bubble scraping, probe floating detection is performed;

[0011] Step S6: In the non-bubble state, different liquid adding conditions are detected by using the probe floating;

[0012] Step S7: In the non-bubble state, the concentration mutation lasts for a period of time, and the probe floating detection is performed;

[0013] Step S8: In a non-bubble state and a bumpy vehicle running state, performing a probe floating detection;

[0014] Step S9: Perform normal measurement in a non-bubble state and normal working conditions.

[0015] As a preferred embodiment, in step S2, the status detection is performed at intervals of 5-10 minutes. If it is recognized that there is no abnormality in the status, the current liquid level, temperature, time and concentration values ​​are recorded in EEPROM, which are historical record values.

[0016] As a preferred embodiment, after each power-on in step S1 or after an abnormal state is identified in step S2, the current value is compared with the historical record value, the operating conditions are distinguished according to the temperature and liquid level state changes, and the concentration output strategy is determined according to the operating conditions.

[0017] As a preferred embodiment, if the liquid adding condition does not occur in step S6, the concentration should not change significantly. If a significant change occurs, the historical value output is maintained for 3-5 minutes. If the liquid adding condition occurs, the concentration can be output according to the actual change.

[0018] As a preferred embodiment, in step S7, if the current urea consumption rate is much higher than the historical value, the liquid level detection function is judged to be abnormal, and the liquid level value is outputted at the historical value for 3-5 minutes. If the urea consumption rate is within a reasonable range, it is updated in real time.

[0019] As a preference, in step S5, the internal temperature is detected after the bubbles are scraped off. If the temperature changes significantly (increases or decreases), the concentration judgment range should be multiplied by a corresponding coefficient to adapt to the effect of the temperature change on the concentration.

[0020] As a preferred embodiment, if the temperature changes significantly (increases or decreases), the environmental changes are judged based on the changes and the corresponding operating condition strategy (such as thawing, etc.) is triggered.

[0021] As a preferred embodiment, if the power is turned off and on within a short period of time in step S8, it can be judged based on the time interval that if the interval is less than 3 minutes, the concentration and liquid level state should not change significantly.

[0022] As a preferred embodiment, in step S4, the bubbles are scraped off by rotating a dense brush, a rotating shaft is provided at the upper center of the dense brush, and a telescopic rod is provided at the lower center of the dense brush, and the lower end of the telescopic rod is connected to a detection probe.

[0023] As another preferred embodiment, the upper end of the telescopic rod is connected to the upper end of the cylinder shaft which is connected to a motor, and the shaft is a hollow structure, a cylinder is provided inside the shaft, the left and right sides of the cylinder are fixedly connected to the shaft, and the lower end of the cylinder is connected to the telescopic rod, the telescopic rod runs through the entire dense burrs, and the telescopic rod includes a fixed rod and an extension rod, the fixed rod is sealingly connected to the shaft, and the lower end of the fixed rod is connected to the extension rod.

[0024] Beneficial effects of the present invention:

[0025] (1) In the present invention, step S2 is set to detect the urea quality state and distinguish whether it is a bubble state or a non-bubble state. In this way, the non-bubble state can be detected under other working conditions. First, it is determined whether a liquid addition condition occurs, and then it is determined whether there is a sudden change in concentration, the bumpy running state of the vehicle, and finally the normal working condition. The urea detection conditions under various conditions are considered from multiple aspects to ensure that the urea concentration detection is more accurate.

[0026] (2) In the present invention, a dense brush is provided to scrape off bubbles. Under normal circumstances, the dense brush can rotate to remove bubbles. If there are unusual circumstances, the probe can also be floated to detect the urea concentration at different heights for comparison to ensure more accurate detection, thereby preventing false alarms.

[0027] (3) In the present invention, a cylinder is arranged inside a rotating shaft. When the rotating shaft drives a dense brush to scrape off bubbles, the detection probe will also rotate accordingly, thereby achieving internal stirring and defoaming. Then, a telescopic rod is used to adjust the insertion length of the detection probe, thereby measuring urea concentrations at different heights. The urea concentrations at different heights are used to compare historical data values, thereby achieving high detection accuracy.

[0028] In summary, this method has the advantages of comprehensive consideration, accurate concentration detection in both bubble and non-bubble states, comprehensive defoaming methods, and data prevention of false alarms, and is particularly suitable for the field of vehicle engine technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0030] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0031] Figure 2 It is a schematic diagram of the process structure of recording historical record values ​​in the present invention.

[0032] Figure 3 It is a schematic diagram of the structure of the dense brush in the present invention.

[0033] Figure 4 It is a schematic diagram of the position structure of the telescopic rod in the present invention. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present invention are clearly and completely described below in conjunction with the accompanying drawings.

[0035] Embodiment 1

[0036] like Figures 1 to 4 As shown, the present invention provides a strategy method for preventing false alarms of urea quality sensor detection, including step S1: starting with power on;

[0037] Step S2: state detection;

[0038] Step S3: Bubble state or non-bubble state;

[0039] Step S4: scraping off bubbles in the bubble state, and then entering the non-bubble state;

[0040] Step S5: If bubbles still exist after the bubble scraping, probe floating detection is performed;

[0041] Step S6: In the non-bubble state, different liquid adding conditions are detected by using the probe floating;

[0042] Step S7: In the non-bubble state, the concentration mutation lasts for a period of time, and the probe floating detection is performed;

[0043] Step S8: In a non-bubble state and a bumpy vehicle running state, performing a probe floating detection;

[0044] Step S9: Perform normal measurement in a non-bubble state and normal working conditions.

[0045] Furthermore, in step S2, a status check is performed at intervals of 5-10 minutes. If it is recognized that there is no abnormality in the status, the current liquid level, temperature, time and concentration values ​​are recorded in the EEPROM, which are historical record values. The conventional operating condition measurement of step S9 is performed on the status without abnormality, and the obtained value is the historical record value, which is used to compare the measured value under the unconventional operating condition, and the function of preventing false alarms is realized by comparison.

[0046] Furthermore, after each power-on in step S1 or after an abnormal state is identified in step S2, the current value is compared with the historical record value, the operating conditions are distinguished according to the temperature and liquid level state changes, and the concentration output strategy is determined according to the operating conditions to avoid false concentration reports.

[0047] Furthermore, if the liquid adding condition does not occur in the step S6, the concentration should not change significantly. If a significant change occurs, the historical value output is maintained for 3-5 minutes. If the liquid adding condition occurs, the concentration can be output according to the actual change. There are three situations under the liquid adding condition. The first is that the liquid adding condition does not occur and the concentration is normal. The second is that the liquid adding condition does not occur and the concentration is abnormal. The third is that the liquid adding condition occurs and the concentration changes. The first can be measured normally, and the second needs to be measured continuously for a period of time to ensure that the numerical output tends to a stable value. The third is output according to the actual change, and then the probe floats for detection, which can effectively prevent data misreporting.

[0048] Furthermore, in step S7, if the current urea consumption rate is much higher than the historical value, the liquid level detection function is judged to be abnormal, and the liquid level value is outputted at the historical value for 3-5 minutes. If the urea consumption rate is within a reasonable range, it is updated in real time. During the concentration mutation process, if the current urea consumption rate is much higher than the historical value, the liquid level value is set to the liquid level value identified in step S2, and then continuously outputted for 3-5 minutes, so that the data value tends to be stable. Under normal circumstances, it is updated in real time, which is simple, convenient and comprehensive.

[0049] Furthermore, in step S5, the internal temperature is detected after the bubbles are scraped off. If there is a significant change in temperature (increase or decrease), the concentration judgment range should be multiplied by a corresponding coefficient to adapt to the influence of the temperature change on the concentration. The bubble scraping is performed by rotating the dense brush 1, and then the detection probe 4 will also rotate to defoam the inside. Stirring may cause the internal temperature to change, so the internal temperature is detected after the bubbles are scraped off. If there is a significant change, the concentration judgment range should be multiplied by a corresponding coefficient to adapt to the influence of the temperature change on the concentration to ensure the accuracy of the numerical value.

[0050] Furthermore, if the temperature changes significantly (increases or decreases), the environmental changes are judged based on the changes and the corresponding operating conditions strategy (such as thawing, etc.) is triggered. Then, if the temperature changes significantly, it is also necessary to judge based on the current environment. If it is winter, the car needs to be thawed and warmed up.

[0051] Furthermore, if the power is turned off and on within a short period of time in step S8, it can be judged based on the time interval. If the interval is short, the concentration and liquid level should not change significantly. If a significant change occurs, the value is inaccurate and has no reference value. If a significant change occurs within an interval of more than 5 minutes, it indicates that there is a problem with the urea quality and manual intervention is required.

[0052] Furthermore, in step S4, bubbles are scraped off by rotating a dense brush 1, a rotating shaft 2 is provided at the upper end of the center position of the dense brush 1, and a telescopic rod 3 is provided at the lower end of the center position of the dense brush 1, and the lower end of the telescopic rod 3 is connected to a detection probe 4. Bubble scraping can be achieved by rotating the dense brush 1, but a small amount of bubbles may be missed. The detection probe 4 can also be rotated to stir and defoam, and the heat generated by the stirring can be used to defoam, thereby reducing the influence of bubbles on the detection value. The detection process is carried out by floating up and down, which can also effectively avoid the influence of bubbles on the detection value and prevent false data reports.

[0053] Furthermore, the upper end of the telescopic rod is connected to the upper end of the cylinder shaft 2, which is connected to a motor, and the shaft 2 is a hollow structure. A cylinder 5 is arranged inside the shaft 2. The left and right sides of the cylinder 5 are fixedly connected to the shaft 2, and the lower end of the cylinder 5 is connected to the telescopic rod 3. The telescopic rod 3 runs through the entire dense burr 1, and the telescopic rod 3 includes a fixed rod 31 and an extension rod 32. The fixed rod 31 is sealed with the shaft 2, and the lower end of the fixed rod 31 is connected to the extension rod 32. The bubble scraping not only utilizes the dense brush 1 for rotation and scraping, but also utilizes the rotation of the telescopic rod 3 and the detection probe 4 to achieve stirring and defoaming. The cylinder 5 works to realize the floating detection of the probe, and detects different heights of urea to avoid data errors due to superficial detection and incomplete elimination of bubbles at the upper end. Floating detection and comparison of historical data values ​​are used to obtain a normal numerical range, thereby achieving the preparation of detection accuracy and the accuracy of reporting.

[0054] Working process: First, power on the urea quality sensor, and then perform a status check on the entire system. If the status is normal, the current liquid level, temperature, time and concentration values ​​are recorded in the EEPROM, which is the historical record value. The status recognition is performed every 3-5 minutes, and the historical record value is obtained by comparing multiple sets of data. After each power-on or abnormal status is recognized, the current value is compared with the historical record value, and the working conditions are distinguished according to the changes in the temperature and liquid level status. The output strategy of the concentration is determined according to the working conditions to avoid false alarms of concentration and determine whether there are false alarms:

[0055] 1. Determine whether the liquid addition condition occurs during power-off based on historical data:

[0056] ① If there is no liquid addition condition, the concentration should not change significantly. If there is a significant change, the historical value output should be maintained for a certain period of time;

[0057] ② If liquid addition occurs, the concentration can be output according to the actual changes;

[0058] 2. Determine urea consumption rate based on historical data:

[0059] ① If the current urea consumption rate is much higher than the historical value, the liquid level detection function is judged to be abnormal, and the liquid level value is output at the historical value (3-5min);

[0060] ② If the urea consumption rate is within a reasonable range, it will be updated in real time;

[0061] 3. Determine the concentration status based on historical temperature changes:

[0062] ① If the temperature changes significantly (increases or decreases), the concentration judgment range should be multiplied by the corresponding coefficient to adapt to the effect of temperature change on concentration;

[0063] ② If the temperature changes significantly (increases or decreases), the environment changes are judged based on the changes and the corresponding working condition strategy (such as thawing, etc.) is triggered;

[0064] 4. Determine the status based on time changes:

[0065] ① If the power is turned off and on within a short period of time, the concentration and liquid level should not change significantly if the interval is less than 3 minutes.

[0066] The entire strategy to prevent false alarms makes corresponding judgments and subsequent detection methods for various situations encountered during the test process. It uses the floating probe to detect different heights, effectively degassing and eliminating the impact of bubbles on numerical detection, preventing false alarms of numerical values ​​and making data detection more accurate.

[0067] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by the terms "front and back", "left and right", etc. are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or component referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the invention.

[0068] Of course, in the present technical solution, those skilled in the art should understand that the term "one" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element may be one, while in another embodiment, the number of the element may be multiple, and the term "one" should not be understood as a limitation on the quantity.

[0069] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art under the technical guidance of the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A strategy method for preventing false alarms in urea quality sensor detection, characterized in that: include Step S1: Power on and start; Step S2: state detection; Step S3: Bubble state or non-bubble state; Step S4: scraping off bubbles in the bubble state, and then entering the non-bubble state; Step S5: If bubbles still exist after the bubble scraping, probe floating detection is performed; Step S6: In the non-bubble state, different liquid adding conditions are detected by using the probe floating; Step S7: In the non-bubble state, the concentration mutation lasts for a period of time, and the probe floating detection is performed; Step S8: In a non-bubble state and a bumpy vehicle running state, performing a probe floating detection; Step S9: Perform normal measurement in a non-bubble state and normal working conditions.

2. A strategy method for preventing false alarms in urea quality sensor detection according to claim 1, characterized in that: In step S2, the status detection is performed at intervals of 5-10 minutes. If it is recognized that there is no abnormality in the status, the current liquid level, temperature, time and concentration values ​​are recorded in the EEPROM, which is the historical record value.

3. The strategy method for preventing false alarms in urea quality sensor detection according to claim 1, characterized in that: After each power-on in step S1 or after an abnormal state is identified in step S2, the current value is compared with the historical record value, the working condition is distinguished according to the temperature and liquid level state changes, and the concentration output strategy is determined according to the working condition.

4. A strategy method for preventing false alarms in urea quality sensor detection according to claim 1, characterized in that: If the liquid adding condition does not occur in the step S6, the concentration should not change significantly. If a significant change occurs, the historical value output is maintained for 3-5 minutes. If the liquid adding condition occurs, the concentration can be output according to the actual change.

5. The strategy method for preventing false alarms in urea quality sensor detection according to claim 1, characterized in that: In step S7, if the current urea consumption rate is much higher than the historical value, it is determined that the liquid level detection function is abnormal, and the liquid level value is outputted at the historical value for 3-5 minutes. If the urea consumption rate is within a reasonable range, it is updated in real time.

6. A strategy method for preventing false alarms in urea quality sensor detection according to claim 1, characterized in that: In step S5, the internal temperature is detected after the bubbles are scraped off. If the temperature changes significantly (increases or decreases), the concentration judgment range should be multiplied by the corresponding coefficient to adapt to the influence of the temperature change on the concentration.

7. A strategy method for preventing false alarms in urea quality sensor detection according to claim 6, characterized in that: If the temperature changes significantly (increases or decreases), the environmental changes are judged based on the changes and the corresponding working condition strategy (such as thawing, etc.) is triggered.

8. The strategy method for preventing false alarms in urea quality sensor detection according to claim 1, characterized in that: If the power is turned off and on within a short period of time in step S8, it can be determined based on the time interval that if the interval is less than 3 minutes, the concentration and liquid level should not change significantly.

9. The strategy method for preventing false alarms in urea quality sensor detection according to claim 1, characterized in that: In step S4, bubbles are scraped off by rotating a dense brush (1), a rotating shaft (2) is provided at the upper center of the dense brush (1), and a telescopic rod (3) is provided at the lower center of the dense brush (1), and the lower end of the telescopic rod (3) is connected to a detection probe (4).

10. A strategy method for preventing false alarms in urea quality sensor detection according to claim 9, characterized in that: The upper end of the telescopic rod is connected to the upper end of the cylinder rotating shaft (2) which is connected to a motor, and the rotating shaft (2) is a hollow structure. A cylinder (5) is arranged inside the rotating shaft (2). The left and right sides of the cylinder (5) are fixedly connected to the rotating shaft (2), and the lower end of the cylinder (5) is connected to the telescopic rod (3). The telescopic rod (3) runs through the entire dense burr (1), and the telescopic rod (3) comprises a fixed rod (31) and an extension rod (32). The fixed rod (31) is sealedly connected to the rotating shaft (2), and the lower end of the fixed rod (31) is connected to the extension rod (32).

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