Water level detection method for liquid heater

Abstract

The embodiment of the invention discloses a water level detection method for a liquid heater, and relates to the technical field of water level detection.The liquid heater comprises a liquid container and a water level detection area arranged on the side wall of the liquid container, and detection electrodes distributed longitudinally in a staggered mode are arranged in the water level detection area. Obtaining self-capacitance data of the detection electrode; if the self-capacitance data meets a first preset condition, determining the corresponding detection electrode as a target detection electrode, collecting mutual capacitance data of the target detection electrode, judging whether the mutual capacitance data meets a second preset condition or not, and determining the current water level according to a judgment result; and if the self-capacitance data does not meet the first preset condition, determining a target detection electrode based on pre-acquired mutual capacitance data of the detection electrode, and acquiring a mutual capacitance detection water level corresponding to the target detection electrode to determine the current water level.

Description

Technical Field

[0001] The present specification relates to the technical field of water level detection, and in particular to a water level detection method for a liquid heater. Background Art

[0002] With the improvement of people's living standards and the enhancement of health awareness, liquid heaters such as health kettles and tea bar machines are increasingly used in daily life. These devices provide users with a convenient drinking and health experience by heating and boiling liquids such as water and various health ingredients (such as tea, beans, and porridge). During the operation of the liquid heater, water level detection is a vital function that is directly related to water inlet control, overflow prevention control, and overall safety and stability. For example, during the water inlet control process, the liquid level detection needs to meet the water inlet requirements of different water inlets; during the overflow prevention control process, the liquid level detection needs to detect the overflow prevention level under different water inlets in a timely manner.

[0003] At present, the water level detection technology of liquid heaters mainly relies on setting capacitor electrodes inside the liquid container, and realizing liquid level detection by detecting the influence of liquid level fluctuation on the capacitance value of the capacitor electrode. Although this technology can meet the needs of liquid level detection to a certain extent, its limitations are also obvious. First of all, this technology requires that the liquid inside the liquid heater must meet the conditions of liquid level fluctuation. When the liquid level is static, the actual water level cannot be accurately obtained because the change of capacitance value cannot be detected. This may cause inconvenience in practical applications, especially in scenarios where precise control of the liquid level is required. Secondly, the existing liquid level detection technology mostly adopts a single detection method, which is highly dependent on the detection accuracy. Once a fault or error occurs during the detection process, it will directly affect the subsequent water inlet or heating process of the liquid heater, and may even cause safety hazards. In addition, in practical applications, due to the influence of various factors (such as ambient temperature, medium characteristics, etc.), there may be errors in the liquid level detection results. The existing liquid level detection technology also lacks an effective means to confirm the detection results, which affects the normal operation of the liquid heater. For example, during the water inlet control process, if the liquid level detection is inaccurate, it may cause excessive or insufficient water inflow, affecting the user experience; during the overflow prevention control process, if the overflow prevention level cannot be detected in time, liquid overflow may occur, causing equipment damage or safety accidents.

[0004] Therefore, the current water level detection method relies on liquid level fluctuations, has limitations in application scenarios, and uses a single detection method, which is highly dependent on the detection results and lacks a process for confirming the detection results, affecting the safe operation requirements of the liquid heater. Summary of the invention

[0005] One or more embodiments of the present specification provide a water level detection method for a liquid heater, which is used to solve the following technical problems: the current water level detection method relies on liquid level fluctuations, has limitations in application scenarios, and uses a single detection method, which is highly dependent on the detection results and lacks a process for confirming the detection results, affecting the safe operation requirements of the liquid heater.

[0006] One or more embodiments of this specification adopt the following technical solutions:

[0007] One or more embodiments of the present specification provide a water level detection method for a liquid heater, wherein the liquid heater comprises a liquid container and a water level detection area arranged on a side wall of the liquid container, wherein the water level detection area is provided with detection electrodes distributed in a longitudinally staggered manner, and wherein the method comprises: receiving a water level detection instruction, and acquiring self-capacitance data of the detection electrode; if the self-capacitance data satisfies a first preset condition, determining the corresponding detection electrode as a target detection electrode, collecting mutual capacitance data of the target detection electrode, determining whether the mutual capacitance data satisfies a second preset condition, and determining the current water level according to the determination result; if the self-capacitance data does not satisfy the first preset condition, determining the target detection electrode based on the mutual capacitance data of the detection electrode acquired in advance, and acquiring the mutual capacitance detection water level corresponding to the target detection electrode to determine the current water level.

[0008] Further, it is determined whether the mutual capacitance data satisfies a second preset condition, and the current water level is determined according to the determination result, specifically including: when the mutual capacitance data reaches a preset mutual capacitance water judgment threshold, it is determined that the second preset condition is met, and the mutual capacitance detection water level corresponding to the target detection electrode is determined as the current water level; when the mutual capacitance data does not reach the preset mutual capacitance water judgment threshold, it is determined that the second preset condition is not met, the self-capacitance detection water level corresponding to the target detection electrode is obtained, and the current water level is determined based on the self-capacitance detection water level.

[0009] Through the above technical solution, by pre-testing and setting the mutual capacitance water level judgment threshold, it is possible to more accurately judge whether the current water level has triggered the detection water level of a specific detection electrode. The threshold-based judgment method avoids misjudgment caused by water level fluctuations or sensor errors, and improves the accuracy of water level detection. The technical solution can adapt to the detection needs under different water level conditions. No matter whether the liquid level rises, falls or fluctuates, as long as the real-time mutual capacitance data is compared with the preset threshold, the current water level can be accurately judged, and stable performance can be maintained under various water level changes. The water judgment threshold is used to judge whether the detection electrode has been covered with enough water, which can more accurately reflect the changes in the water level. Accurate water level detection can provide users with more accurate water level information, avoid heating interruptions, liquid overflow and other problems caused by misjudgment, improve user convenience, and enhance user trust and satisfaction with the device.

[0010] Further, determining the current water level based on the self-capacitance detection water level specifically includes: determining the first target detection electrode and the second target detection electrode whose self-capacitance data satisfy a first preset condition, respectively obtaining the self-capacitance detection water levels corresponding to the first target detection electrode and the second target detection electrode, and determining the maximum value of the self-capacitance detection water levels as the current water level; or, determining a water level interval based on the self-capacitance detection water level corresponding to the target detection electrode, and determining the current water level with the maximum value of the water level interval.

[0011] Through the above technical scheme, by combining the detection data of self-capacitance and mutual capacitance, the current water level can be judged more accurately. When the mutual capacitance data does not reach the preset water judgment threshold, the self-capacitance detection water level is used for supplementary judgment, which can reduce the misjudgment caused by single sensor error or water level fluctuation, and improve the accuracy of water level detection. The technical scheme provides two methods for determining the current water level: one is to directly take the maximum value of the self-capacitance detection water level of the target detection electrode that meets the conditions; the other is to determine the water level interval based on the self-capacitance detection water level corresponding to the target detection electrode, and take the maximum value of the interval. These two methods can be flexibly selected according to actual conditions to adapt to different water level detection needs. By combining multiple detection electrodes and corresponding thresholds for judgment, it can more reliably respond to various water level changes. Even if a detection electrode fails or has an error, the system can still make an accurate judgment through other detection electrodes and judgment logic, thereby enhancing the robustness of the system; by taking the maximum value of the self-capacitance detection water level of the target detection electrode that meets the conditions or the maximum value of the water level interval as the current water level, the result error caused by water level fluctuation or acquisition error can be reduced, and accurate water level detection results are guaranteed.

[0012] Furthermore, in the process of determining the mutual capacitance data and the mutual capacitance water judgment threshold, the periodically collected mutual capacitance data is obtained; and the type of water level change in the liquid container is determined by the change pattern of the mutual capacitance data relative to the mutual capacitance water judgment threshold, wherein the water level change type includes water level rise, water level drop and water level fluctuation.

[0013] Through the above technical scheme, by periodically collecting mutual capacitance data, the water level changes in the liquid container can be monitored in real time, which can ensure that the equipment can operate safely and effectively according to the current water level status at any time; by comparing the collected mutual capacitance data with the preset mutual capacitance water judgment threshold, the rise, fall or fluctuation of the water level can be accurately judged, thereby improving the accuracy of detection; accurate judgment of the type of water level change helps to prevent dry burning caused by too low water level, and the risk of overflow or leakage caused by too high water level; by timely detecting water level fluctuations, safety hazards caused by violent shaking or instability of the liquid can also be prevented; based on the analysis of mutual capacitance data, intelligent detection of water level changes is realized, reducing the need for manual intervention and improving the degree of automation of the equipment; according to the type of water level change, the liquid heater can automatically adjust its working mode or issue a corresponding alarm, thereby improving the level of intelligence.

[0014] Furthermore, when the water level change type is water level fluctuation, the method also includes: judging whether a preset trigger signal is detected or whether the real-time water temperature in the liquid level container is less than a preset temperature threshold; if so, determining that the water level fluctuation means that the liquid container is in use, pausing water level detection until it is determined that the self-capacitance data does not meet the first preset condition and then restarting it; otherwise, determining that the water level fluctuation is a liquid surface boiling fluctuation caused by heating and boiling.

[0015] Through the above technical scheme, by detecting the preset trigger signal (such as the action of lifting the kettle and putting it back into the tea bar machine) and the water temperature, the cause of the current water level fluctuation can be automatically identified, and subsequent operations can be performed under different causes. When the user operates the liquid container (such as adding or removing liquid), water level fluctuations are normal. By pausing the water level detection function, false alarms or interference caused by this can be avoided, thereby improving the accuracy and reliability of monitoring; by distinguishing between water level fluctuations caused by user operations and liquid surface fluctuations caused by heating and boiling, the heating process can be controlled more accurately.

[0016] Furthermore, when the water level fluctuation is a liquid surface boiling fluctuation caused by heating and boiling, the method also includes: obtaining the self-capacitance detection water level and the mutual capacitance detection water level corresponding to each target detection electrode, and when it is detected that the self-capacitance detection water level and / or the mutual capacitance detection water level reaches the preset first anti-overflow water level, starting the anti-overflow detection process; in the anti-overflow detection process, when it is detected that the self-capacitance detection water level and / or the mutual capacitance detection water level reaches the second anti-overflow water level, adjusting the heating parameters of the liquid heater based on the preset heating strategy.

[0017] Through the above technical solution, by real-time monitoring of the liquid level and starting the overflow prevention detection process when the preset overflow prevention water level is reached, it is possible to promptly detect and respond to potential liquid overflow risks, thereby effectively avoiding safety accidents caused by liquid overflow and greatly improving the safety of the equipment; combining the two detection methods of self-capacitance and mutual capacitance, it is possible to more accurately judge the liquid level changes and reduce equipment failures or misoperations caused by misjudgment, thereby enhancing stability and reliability; on the premise of ensuring safety, it is possible to intelligently adjust the heating parameters to avoid unnecessary heating interruptions and maintain heating efficiency, thereby providing users with a more stable and efficient heating experience, while reducing false alarms and interference, and improving user convenience and satisfaction.

[0018] Furthermore, based on the mutual capacitance data of the detection electrodes acquired in advance, the target detection electrode is determined, specifically including: obtaining the real-time mutual capacitance value of the detection electrodes; judging the relationship between the real-time mutual capacitance value and the corresponding mutual capacitance no water judgment threshold, and determining the target detection electrode with the detection electrode whose real-time mutual capacitance value is less than the mutual capacitance no water judgment threshold.

[0019] Through the above technical scheme, by setting the mutual capacitance no water judgment threshold, slight changes in the water level can be detected more sensitively. When the real-time mutual capacitance value is less than the no water judgment threshold, it can be judged that the corresponding detection electrode has touched water, thereby responding to water level changes in time and improving the sensitivity of water level detection; it can accurately identify which detection electrodes have touched water, regardless of whether they are completely covered or partially covered by the water level. As long as their real-time mutual capacitance value is less than the no water judgment threshold, they can be determined to be in a water-touching state; by pre-setting the mutual capacitance no water judgment threshold and making comparative judgments during the real-time detection process, the water level detection process can be simplified and the detection efficiency can be improved.

[0020] Furthermore, the mutual capacitance detection water level corresponding to the target detection electrode is obtained to determine the current water level, specifically including: obtaining a first mutual capacitance detection water level and a second mutual capacitance detection water level of the target detection electrode, wherein the first mutual capacitance detection water level is less than the second mutual capacitance detection water level; determining whether the mutual capacitance data of the target detection electrode is higher than a preset mutual capacitance water judgment threshold, and if so, determining the current water level according to the first mutual capacitance detection water level, otherwise determining the current water level according to the second mutual capacitance detection water level.

[0021] Through the above technical scheme, according to the two different detection water levels of the target detection electrode (the first mutual capacitance detection water level and the second mutual capacitance detection water level), and combined with the comparison of the real-time mutual capacitance value and the preset threshold, the current water level can be located more accurately, the accuracy of water level detection is improved, and the detection resolution is increased, so that the system can more finely reflect the changes in water level; when there are multiple target detection electrodes, the real-time mutual capacitance value and the corresponding detection water level of each electrode can be comprehensively considered to make a more robust water level judgment, and by introducing the mutual capacitance water judgment threshold, it can more flexibly respond to detection needs under different water level conditions; the above logical judgment method not only simplifies the water level detection process, but also improves the efficiency and accuracy of detection. Accurate water level detection can provide users with more accurate water level information and avoid problems such as heating interruption and liquid overflow due to misjudgment.

[0022] Furthermore, the method also includes: when the acquired real-time mutual capacitance values ​​are not less than the corresponding mutual capacitance no-water judgment threshold, determining that the current water level is lower than the lowest detected water level of the water level detection area, stopping the water level detection process and triggering a water shortage signal.

[0023] Furthermore, the process of determining the self-capacitance data and the first preset condition specifically includes: collecting the real-time self-capacitance value of the detection electrode, determining the difference according to the real-time self-capacitance value and the real-time baseline value of the preset corresponding self-capacitance change following the baseline, and determining the self-capacitance data of the detection electrode by the absolute value of the difference; when the self-capacitance data is greater than the preset self-capacitance water touch judgment threshold, determining that the self-capacitance data of the detection electrode meets the first preset condition and is determined to be a dynamic liquid level; when the self-capacitance data is not greater than the preset self-capacitance judgment threshold, determining that the self-capacitance data of the detection electrode does not meet the first preset condition and is determined to be a static liquid level.

[0024] Through the above technical scheme, the real-time self-capacitance value and the self-capacitance change following baseline that changes with the self-capacitance value are used to collect self-capacitance data. By real-time monitoring of the capacitance value of the target detection electrode and comparing it with the real-time water inlet following baseline, it is possible to accurately determine whether the water level has reached the predetermined target, thereby reducing misjudgment caused by interference factors and improving the accuracy of self-capacitance detection. In addition, by utilizing the property that the change of the self-capacitance value will only occur under liquid level fluctuation conditions, the absolute value of the difference between the real-time self-capacitance value and the real-time following value is used as the self-capacitance data, and both liquid level fluctuations of liquid level rise and liquid level drop can be detected, thereby improving the applicability of the scenario. In addition, the relationship between the self-capacitance data and the self-capacitance judgment threshold is used to detect the liquid level state, which is convenient for targeted detection of different liquid level states in the subsequent process.

[0025] At least one of the above technical solutions adopted in the embodiments of this specification can achieve the following beneficial effects:

[0026] 1. In view of the problem that static liquid level cannot be accurately detected in the prior art, the embodiments of this specification realize water level detection under static liquid level by combining the judgment logic of self-capacitance data and mutual capacitance data; even if the liquid level is in a static state, the target detection electrode can be determined by the pre-acquired mutual capacitance data, and the current water level can be judged accordingly, thus breaking the limitation of relying on liquid level fluctuations;

[0027] 2. In addition, the dual detection mechanism with self-capacitance preliminary screening and mutual capacitance further confirmation reduces the error and failure risk that may be caused by a single detection method. By setting the first preset condition and the second preset condition, the current water level can be judged more accurately, reducing the problems of subsequent water inflow or heating process caused by inaccurate detection, and improving the safety and stability of the liquid heater;

[0028] 3. The prior art lacks effective means to confirm the detection results, but the embodiments of this specification actually achieve a secondary confirmation of the detection results by introducing the judgment logic of mutual capacitance data. When the self-capacitance data meets the first preset condition, the mutual capacitance data is further collected and judged. This double confirmation mechanism improves the reliability of the detection results;

[0029] 4. Through precise capacitance detection technology and logical judgment, it can adapt to the influence of different ambient temperatures and medium characteristics on the liquid level detection results to a certain extent. Through the dual detection mechanism and the setting of preset conditions, the interference of such influence on the normal operation and safety of the liquid heater is reduced; precise water level detection can provide users with more accurate water level information, avoid heating interruption, liquid overflow and other problems caused by misjudgment, and improve user experience. By real-time monitoring of the water level and taking corresponding measures (such as stopping heating when there is a lack of water, issuing a warning when the water level is too high, etc.), it can ensure the normal operation of the equipment and extend its service life, thereby enhancing the safety and stability of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of this specification or the prior art, the following briefly introduces the drawings required for use in the embodiments or the prior art description. Obviously, the drawings described below are only some embodiments recorded in this specification. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. In the drawings:

[0031] Figure 1 A schematic flow chart of a water level detection method for a liquid heater provided in an embodiment of this specification;

[0032] Figure 2 A schematic diagram of the distribution of electrodes in a water level detection area provided in an embodiment of this specification;

[0033] Figure 3 A schematic diagram of a real-time capacitance change curve and a real-time water inflow following baseline of an electrode sheet provided in an embodiment of this specification;

[0034] Figure 4 A schematic diagram of a determination process of a first preset condition provided in an embodiment of this specification;

[0035] Figure 5 A schematic diagram of a determination process of a second preset condition provided in an embodiment of this specification;

[0036] Figure 6 A water level detection flow chart provided in an embodiment of this specification when the first preset condition is not met. DETAILED DESCRIPTION

[0037] In order to enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification will be clearly and completely described below in conjunction with the drawings in the embodiments of this specification. Obviously, the described embodiments are only part of the embodiments of this specification, not all of the embodiments. Based on the embodiments of this specification, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of this specification.

[0038] The embodiment of this specification provides a water level detection method for a liquid heater. It should be noted that the execution subject in the embodiment of this specification can be a server or any device with data processing capabilities. Figure 1 A flow chart of a water level detection method for a liquid heater provided in an embodiment of this specification is shown as follows: Figure 1 As shown, it mainly includes the following steps:

[0039] Step S101, receiving a water level detection instruction, and acquiring self-capacitance data of the detection electrode.

[0040] In one embodiment of the present specification, the embodiment of the present specification provides a water level detection method for a liquid heater, which is applied to the liquid heater. The liquid heater includes a liquid container, a water pump, a heating device, and a water level detection area arranged on the side wall of the liquid container, and a plurality of longitudinally distributed electrode sheets are provided in the water level detection area. Figure 2 This is a schematic diagram of the distribution of electrodes in a water level detection area provided in an embodiment of this specification. It should be noted that: Figure 2 In order to meet the requirements of 500~1400ml tea bar machine, the design of touch capacitance distribution example, in the actual design process, the number or position of the electrode sheet can be adjusted, only Figure 2 The embodiments of this specification are described by taking the example of Figure 2 As shown, a capacitance detection plate is provided in the kettle, including a plurality of staggered electrode sheets, wherein a certain space is reserved between two adjacent electrode sheets, which is used as a judgment node for the water level line, to ensure that only one electrode sheet in a single row of electrode sheets can detect capacitance changes at the same time, thereby improving the detection accuracy. The electrode sheets are arranged in a staggered manner, which can effectively avoid direct interference between adjacent electrode sheets, and a certain space is reserved between two adjacent electrode sheets, which is used as a judgment node for the water level line. It is ensured that only one electrode sheet in a single row of electrode sheets can detect capacitance changes at the same time, avoiding misjudgment caused by multiple electrode sheets detecting capacitance changes at the same time, thereby improving the detection accuracy.

[0041] In addition, during the design process, the 2W principle based on the PCB board ensures that a certain distance is maintained between the two adjacent electrode sheets on the left and right (data interference is likely to occur if the distance is too close). It should be noted that the 2W principle means that in PCB design, adjacent signal lines or components should maintain a sufficient distance to avoid mutual interference. This distance is usually defined as twice the line width (ie 2W). The design of the capacitor detection board in the kettle achieves accurate detection of the water level line through staggered electrode sheets, reserved space between upper and lower adjacent electrode sheets, and based on the 2W principle of the PCB board. This not only improves the accuracy of the detection, but also avoids interference between adjacent electrode sheets, ensuring the reliability of the detection results. In such as Figure 2 The water level detection area shown includes 11 self-capacitance electrode sheets and 5 mutual capacitance combinations. In the 5 mutual capacitance combinations, each mutual capacitance combination corresponds to a mutual capacitance detection electrode sheet.

[0042] like Figure 2 As shown, 11 self-capacitance electrode sheets are arranged in the water level detection area, and each self-capacitance electrode sheet corresponds to a different detection liquid level. For example, the liquid level range that can be detected by self-capacitor G18 is 400-500ml, the liquid level range corresponding to self-capacitor G29 is 400-600ml, self-capacitor G23 and G24 can detect 500-700ml, self-capacitor G25 can detect 600-800ml, self-capacitor G22 can detect 700-900ml, self-capacitor G26 can detect 800-1000ml, self-capacitor G21 can detect 900-1100ml, self-capacitor G27 can detect 1000-1200ml, self-capacitor G20 can detect 1100-1300ml, self-capacitor G28 can detect 1200-1400ml, and self-capacitor G19 can detect 1300-1500ml. Figure 2 In the staggered design shown, each 100ml liquid level has a corresponding detection electrode sheet, which can detect multiple liquid levels within 500-1400ml. For example, the 800ml liquid level can be judged by G25. When the water is submerged or nearly submerged by G25, the detection liquid level corresponding to G25 is triggered, and the purpose of detecting the 800ml liquid level can be achieved. In addition to G25, the purpose of detecting 800ml can also be achieved through the capacitance characteristics corresponding to G26 when water just touches.

[0043] In one embodiment of the present specification, the self-capacitance data of the detection electrode is obtained when the water level detection instruction is received. It should be noted that the water level detection instruction here can be triggered during the water inlet control process, or during the anti-overflow detection process, or in other operating scenarios of the liquid heater, and the embodiment of the present specification does not specifically limit this.

[0044] During the operation of the liquid heater, the temperature inside the kettle will change. As the water temperature inside the kettle changes, the capacitance value of the electrode sheet set on the kettle will also change slowly. This change in capacitance value is not caused by changes in water level, but by changes in temperature. Therefore, when the collected data changes, it is impossible to simply rely on the size of the self-capacitance value to determine whether the electrode sheet is in contact with water. In one embodiment of the present specification, a self-capacitance change following baseline is set, and a corresponding real-time self-capacitance change following baseline is generated through changes in the real-time self-capacitance value of the electrode sheet. The self-capacitance change following baseline is a curve that changes according to a preset change rule and follows the changes in the real-time capacitance data.

[0045] During the change process of the electrode sheet, although the capacitance values ​​of different electrode sheets are different, after contacting water, the change trend of the electrode sheet is consistent, showing the following trend: in the waterless state, the capacitance value is small and stable in a small capacitance value or capacitance range. After the electrode sheet gradually contacts the water, as the water level does not increase, the capacitance value of the electrode sheet gradually increases after the water begins to submerge the electrode sheet. When the water submerges the electrode sheet, the capacitance value of the electrode sheet stabilizes at a larger capacitance value. Therefore, a self-capacitance change following baseline can be introduced to accurately determine whether the current water level has reached the target water level by the relative change of the capacitance value of the electrode sheet. In the program, a self-capacitance change following baseline is set in advance for each electrode sheet, and each electrode sheet corresponds to a different self-capacitance change following baseline. It should be noted that the self-capacitance change following baseline here is a following type baseline, that is, the self-capacitance change following baseline is a real-time curve presented as the real-time capacitance of the electrode sheet changes according to the preset change law.

[0046] Each electrode sheet is tested for water inflow in advance, and the theoretical capacitance change baseline corresponding to each electrode sheet in the absence of interference factors is collected. Based on the curve change law of the theoretical capacitance change curve, the change law of the self-capacitance change following the baseline is determined, and the change law includes constant capacitance value before water, increase or decrease in capacitance value during water level change, and constant capacitance value after water is submerged. Secondly, the actual change speed and change value of the theoretical capacitance change curve are used as the change parameters of the capacitance value increase law of each electrode sheet in water inflow, and the stable capacitance value after the last water submerges the electrode sheet is used as the constant value of the constant capacitance value law after the self-capacitance change follows the baseline. It should be noted that the following method of the self-capacitance change following the baseline here is delayed following, that is, when the real-time self-capacitance data begins to change suddenly, the self-capacitance change following the baseline begins to change according to the change law. In other words, if the real-time self-capacitance data does not change, the corresponding self-capacitance change baseline does not play a role, and it coincides with the waterless capacitance value of the real-time self-capacitance data and the capacitance value is small. It can also be understood that the real-time self-capacitance data does not change, and there is no self-capacitance change baseline value. The judgment standard for the sudden change of real-time self-capacitance data can be set according to the test process and empirical data.

[0047] Figure 3 A schematic diagram of a real-time capacitance change curve of an electrode sheet and a real-time water inflow following baseline provided in an embodiment of this specification, such as Figure 3 As shown in the figure, the relative relationship between the real-time capacitance change curve and the real-time water inflow baseline during the gradual increase of the liquid level is shown. In addition to the process of liquid level increase, it can also be applied to the case of liquid level decrease. The case of liquid level decrease is the opposite process to the process of liquid level increase. The initial state is determined to be the state of water submersion or the state of no water contact according to the size of the self-capacitance value. Figure 3 Take the corresponding liquid level rise as an example to illustrate that when the liquid level does not touch the electrode sheet, the real-time capacitance change curve is stable at a smaller capacitance value, and the real-time water inflow following baseline coincides with the real-time capacitance change curve. As the water level gradually increases, the real-time capacitance value in the real-time capacitance change curve gradually increases. At this time, when a sudden change in the current capacitance value on the electrode sheet is detected, the real-time water inflow following baseline begins to increase slowly according to the preset change rule. Since in this example, the real-time capacitance change curve is not affected by other interference factors, Figure 3In the process, the real-time water inflow following baseline slowly approaches the real-time capacitance value in the real-time capacitance change curve with a preset change rule, until the water submerges the electrode sheet, and the real-time capacitance value in the real-time capacitance change curve stabilizes at a certain value, and the real-time water inflow following baseline coincides with the real-time capacitance change curve again. In this process, the following state of the real-time water inflow following baseline is delayed following, and after the real-time capacitance value stabilizes again when the water submerges the electrode sheet, the real-time water inflow following baseline also coincides with the real-time capacitance change curve with delay. Correspondingly, if the real-time capacitance change curve is the capacitance change caused by temperature, since the capacitance change caused by temperature is relatively slow, in the process of the slow change of the real-time capacitance change curve, the real-time water inflow following curve is delayed following, which will result in a situation where the real-time water inflow following curve changes more slowly; or the capacitance change caused by temperature does not meet the conditions of mutation, resulting in the real-time water inflow following curve not following. In this way, the misjudgment of water level caused by using the capacitance change caused by temperature as the water level judgment standard can be avoided.

[0048] In one embodiment of the present specification, when obtaining the real-time self-capacitance value of the detection electrode, the real-time self-capacitance value of the detection electrode is collected. Under the change of the real-time self-capacitance value, a real-time following baseline is generated. The difference between the real-time self-capacitance value and the real-time baseline value of the real-time following baseline is determined, and the self-capacitance data of the detection electrode is determined by the absolute value of the difference.

[0049] The judgment process of the self-capacitance data and the first preset condition specifically includes: when the self-capacitance data is greater than the preset self-capacitance water touch judgment threshold, it is judged that the self-capacitance data of the detection electrode meets the first preset condition and is determined to be a dynamic liquid level; when the self-capacitance data is not greater than the preset self-capacitance judgment threshold, it is judged that the self-capacitance data of the detection electrode does not meet the first preset condition and is determined to be a static liquid level.

[0050] In one embodiment of the present specification, a self-capacitance water-touching judgment threshold is set according to the theoretical self-capacitance change curve corresponding to each electrode sheet and the self-capacitance change following baseline. It should be noted that the self-capacitance water-touching judgment threshold here is used to judge whether the electrode sheet touches water, that is, the water level detection signal corresponding to this electrode sheet can be triggered when it just touches water. When the self-capacitance data of any electrode sheet among the multiple self-capacitance data is greater than the self-capacitance water-touching judgment threshold, it indicates that the current liquid level has fluctuated. Figure 4 A schematic diagram of a determination process of a first preset condition provided in an embodiment of this specification, such as Figure 4 As shown, it is determined that the self-capacitance data of the detection electrode meets the first preset condition and is determined to be a dynamic liquid level. When the self-capacitance data is not greater than the self-capacitance judgment threshold, it is determined that the self-capacitance data of the detection electrode does not meet the first preset condition and is determined to be a static liquid level.

[0051] Through the above technical scheme, the real-time self-capacitance value and the self-capacitance change following baseline that changes with the self-capacitance value are used to collect self-capacitance data. By real-time monitoring of the capacitance value of the target detection electrode and comparing it with the real-time water inlet following baseline, it is possible to accurately determine whether the water level has reached the predetermined target, thereby reducing misjudgment caused by interference factors and improving the accuracy of self-capacitance detection. In addition, by utilizing the property that the change of the self-capacitance value will only occur under liquid level fluctuation conditions, the absolute value of the difference between the real-time self-capacitance value and the real-time following value is used as the self-capacitance data, and both liquid level fluctuations of liquid level rise and liquid level drop can be detected, thereby improving the applicability of the scenario. In addition, the relationship between the self-capacitance data and the self-capacitance judgment threshold is used to detect the liquid level state, which is convenient for targeted detection of different liquid level states in the subsequent process.

[0052] Step S102: if the self-capacitance data meets the first preset condition, the corresponding detection electrode is determined as the target detection electrode, the mutual capacitance data of the target detection electrode is collected, and it is determined whether the mutual capacitance data meets the second preset condition, and the current water level is determined according to the determination result.

[0053] In one embodiment of the present specification, if the self-capacitance data of the electrode sheet in multiple self-capacitance detection electrodes meets the first preset condition, it means that the current liquid level is a dynamic liquid level. In order to avoid the detection error caused by a single liquid level detection method, the target detection electrode is determined among the multiple detection electrodes that meet the first preset condition. Due to water level fluctuations, there are multiple detection electrodes corresponding to the same detection liquid level. For example, G26 and G21 meet the first preset condition at the same time. In the above example, the two self-capacitance detection electrodes are triggered at the same time. G26 triggers, indicating that the water level is currently in the range of 800-1000 ml, G21 triggers, indicating that the water level is currently in the range of 900-1100 ml, and G22 triggers, indicating that the water level is currently at a water level of 700-900 ml. The detected water level obtained by self-capacitance detection is a water level range. In order to obtain a more accurate water level, the mutual capacitance data can be used to further confirm the specific water level.

[0054] In one embodiment of the present specification, Figure 2 In the electrode distribution shown in FIG. 1 , the right electrode sheet is used as the excitation end, the left electrode sheet is used as the receiving end, and the 12 electrode sheets are combined into 5 mutual capacitance combinations. Figure 2In the water level detection area shown, when two columns of electrodes are provided, including a first array and a second array, the electrodes of the first array have both self-capacitance data and mutual capacitance data (the array where the detection end is located), and the electrodes of the second array only have self-capacitance data (the array where the excitation end is located). Set the first true array (left side) as the detection end of the mutual capacitance, that is, the corresponding mutual capacitance detection electrode, and the second array here only has self-capacitance data, which is the array where the excitation end is located. The right electrode sheet is used as the excitation end and the left electrode sheet is used as the receiving end for explanation. There are many forms of mutual capacitance combinations. The first one uses mutual capacitance as a single-ended mutual capacitance method, that is, the excitation electrode sheet and the detection electrode sheet are in a one-to-one relationship, and it can also be a one-to-two relationship, that is, one excitation end and two detection ends. Next, the description is made in a one-to-one relationship, for example: electrode sheet G24 and / or electrode sheet G23 are the excitation ends, and also serve as the excitation electrode sheets, sending excitation signals to electrode sheet G29, electrode sheet G29 is the detection electrode sheet of the receiving end, used to receive the excitation signal sent by the excitation electrode sheet, the detection water level corresponding to this capacitor combination is about 600ml, and it can also assist in the water level judgment of 400ml. Electrode sheet G22 is the excitation electrode sheet, serving as the excitation end, electrode sheet G25 is the detection electrode sheet, serving as the receiving end, electrode sheet G22 sends an excitation signal to electrode sheet G25, and the detection water level that can be detected by detecting electrode sheet G25 is about 800ml, and it can also assist in the water level judgment of 600ml. Electrode sheet G21 is the excitation electrode sheet, serving as the excitation end, electrode sheet G26 is the detection electrode sheet, serving as the receiving end, electrode sheet G21 sends an excitation signal to electrode sheet G26, and the detection water level that can be detected by detecting electrode sheet G26 is about 1000ml, and it can also assist in the water level judgment of 800ml. Similarly, electrode sheet G20 and electrode sheet G27 are combined into a mutual capacitance combination, wherein electrode sheet G20 is an excitation electrode sheet that sends an excitation signal, and electrode sheet G27 is a detection electrode sheet, which is used to generate real-time mutual capacitance data after receiving the excitation signal sent by the excitation electrode sheet. The mutual capacitance combination of electrode sheet G20 and electrode sheet G27 can detect a liquid level of about 1200ml, and can also assist in the water level judgment of 1000ml; electrode sheet G19 and electrode sheet G28 are combined into a mutual capacitance combination, wherein electrode sheet G19 is an excitation electrode sheet that sends an excitation signal, and electrode sheet G28 is a detection electrode sheet. The detection liquid level corresponding to this mutual capacitance combination is about 1400ml, and can also assist in the water level judgment of 1200ml. For example, the detection of 1200ml uses G20 excitation and G27 acceptance.

[0055] Since only the electrode on the left is the mutual capacitance detection electrode of the mutual capacitance receiving end, in this case, the mutual capacitance detection electrode in the detection electrode (such as G26, G21) is used as the target detection electrode (such as G26), and the detection electrode. That is to say, the target detection electrode here includes two self-capacitance detection electrodes for self-capacitance detection of water contact and the mutual capacitance detection electrode for receiving the excitation signal in the two self-capacitance detection electrodes. In the example where G26 and G21 simultaneously meet the first preset condition, three target detection electrodes are included: self-capacitance detection electrode G26, self-capacitance detection electrode G21 and mutual capacitance detection electrode G26. In the process of self-capacitance detection, mutual capacitance data is collected for the detection electrodes at the same time. By collecting the mutual capacitance data of the target detection electrode, it is determined whether the mutual capacitance data meets the second preset condition, and the current water level is determined according to the determination result.

[0056] Determine whether the mutual capacitance data satisfies a second preset condition, and determine the current water level according to the determination result, specifically including: when the mutual capacitance data reaches a preset mutual capacitance water judgment threshold, determine that the second preset condition is met, and determine the mutual capacitance detection water level corresponding to the target detection electrode as the current water level; when the mutual capacitance data does not reach the preset mutual capacitance water judgment threshold, determine that the second preset condition is not met, obtain the self-capacitance detection water level corresponding to the target detection electrode, and determine the current water level based on the self-capacitance detection water level.

[0057] In one embodiment of the present specification, a mutual capacitance value test is performed on each mutual capacitance combination in advance to collect the mutual capacitance water level judgment threshold corresponding to each mutual capacitance combination, and the mutual capacitance water level judgment threshold includes two types: mutual capacitance water judgment threshold and mutual capacitance no water judgment threshold. Multiple water inflow tests can be performed on each mutual capacitance combination to collect the no water mutual capacitance detection value of the detection electrode of each mutual capacitance combination just touching the water and approaching the no water state, and the no water judgment threshold is determined by the average value of multiple no water mutual capacitance detection values. The area of ​​the electrode sheet covered by the liquid level is controlled to exceed more than half of the area of ​​the detection electrode sheet, and the water mutual capacitance detection value is collected. The mutual capacitance water judgment threshold corresponding to each mutual capacitance combination is determined according to the multiple water mutual capacitance detection values. According to the experimental test results, the real-time mutual capacitance data reflects the capacitive coupling between the excitation electrode sheet and the detection electrode sheet, especially when the detection electrode sheet contacts water, its water contact area will affect the size of the capacitance value. The real-time mutual capacitance data is closely related to the water contact area of ​​the detection electrode sheet. When the water contact area of ​​the detection electrode sheet increases, although the water increases the contact area with the electrode, it actually reduces the effective electric field coupling between the electrodes, thereby reducing the mutual capacitance value. It should be noted that when the real-time mutual capacitance value of the detection electrode in the same mutual capacitance combination is compared with different mutual capacitance water level judgment thresholds, the detection water level of the same detection electrode is different. When the conditional judgment is made with the no-water judgment threshold, it is actually a judgment on whether the minimum detection water level of this detection electrode is triggered; when the conditional judgment is made with the water judgment threshold, it is actually a judgment on whether the maximum detection water level of this detection electrode is triggered.

[0058] Figure 5 A schematic diagram of a determination process of a second preset condition provided in an embodiment of this specification, such as Figure 5 As shown, when the mutual capacitance data of the target mutual capacitance detection electrode in the target detection electrode reaches the preset mutual capacitance water judgment threshold, it should be noted that reaching the mutual capacitance water judgment threshold here includes the mutual capacitance value decreasing to the mutual capacitance water judgment threshold during the liquid level rise, the mutual capacitance value increasing to the mutual capacitance water judgment threshold when the liquid level drops, and the liquid level fluctuates up and down, etc., it is determined to meet the second preset condition, that is, the current water level triggers the detection water level corresponding to this target detection electrode. Since the detection water level here is the water level triggered according to the water judgment threshold, and the water judgment threshold is the threshold corresponding to the area of ​​the electrode sheet covered by the liquid level in the water inlet test exceeding more than half of the detection electrode sheet area, therefore, the detection water level here is the detection water level corresponding to the top of the target detection electrode, which is the maximum detection water level corresponding to this electrode sheet. The mutual capacitance detection water level corresponding to the target mutual capacitance detection electrode in the target detection electrode is determined as the current water level.

[0059] If the mutual capacitance data does not reach the preset mutual capacitance water judgment threshold, it means that the actual water level at this time does not trigger the mutual capacitance detection water level of the target mutual capacitance detection electrode, and it is determined that the second preset condition is not met. It can be understood that the current actual liquid level does not exceed more than half of the target mutual capacitance detection electrode. Therefore, the self-capacitance detection water level corresponding to the target detection electrode is obtained, and the current water level is determined based on the self-capacitance detection water level.

[0060] Through the above technical solution, by pre-testing and setting the mutual capacitance water level judgment threshold, it is possible to more accurately judge whether the current water level triggers the detection water level of a specific detection electrode. The judgment method based on the threshold avoids misjudgment caused by water level fluctuations or sensor errors, and improves the accuracy of water level detection. The technical solution can adapt to the detection needs under different water level conditions. Whether the liquid level rises, falls or fluctuates, as long as the real-time mutual capacitance data is compared with the preset threshold, the current water level can be accurately judged, and stable performance can be maintained under various water level changes. By distinguishing the no-water judgment threshold and the water judgment threshold, the logic of water level detection can be more finely controlled. The no-water judgment threshold is used to judge whether the detection electrode has just touched the water, while the water judgment threshold is used to judge whether the detection electrode has been covered by enough water, which can more accurately reflect the change of the water level. Accurate water level detection can provide users with more accurate water level information, avoid heating interruption, liquid overflow and other problems caused by misjudgment, improve user convenience, and improve user trust and satisfaction with the device.

[0061] Determining the current water level based on the self-capacitance detection water level specifically includes: determining the first target detection electrode and the second target detection electrode whose self-capacitance data meet the first preset condition, respectively obtaining the self-capacitance detection water levels corresponding to the first target detection electrode and the second target detection electrode, and determining the maximum value of the self-capacitance detection water levels as the current water level; or, determining the water level interval based on the self-capacitance detection water level corresponding to the target detection electrode, and determining the current water level with the maximum value of the water level interval.

[0062] In one embodiment of the present specification, the first target detection electrode and the second target detection electrode whose self-capacitance data meet the first preset condition are determined, and the self-capacitance detection water levels corresponding to the first target detection electrode and the second target detection electrode are respectively obtained, and the maximum value of the self-capacitance detection water levels is determined as the current water level. In addition to the above method, the water level interval can also be determined based on the self-capacitance detection water level corresponding to the target detection electrode, and the current water level is determined by the maximum value of the water level interval.

[0063] For example, in the example where G26 and G21 simultaneously meet the first preset condition, if the mutual capacitance data corresponding to G26 does not meet the second preset condition, that is, the actual water level does not trigger the mutual capacitance detection water level 1000ml corresponding to G26, at this time, the self-capacitance detection water level 800ml of G26 and the self-capacitance detection water level 900ml of G21 are obtained. The maximum value 900ml can be taken as the current water level, or 900ml can be taken as the current water level within the range of 800ml-900ml. The self-capacitance detection water level of G26 and G21 was triggered, which means that the actual water level exceeded the self-capacitance detection water level of 800ml of G26 and exceeded the self-capacitance detection water level of 900ml of G21, but did not meet the second preset condition, indicating that the mutual capacitance detection water level of 1000ml of G26 was not reached and there was a certain height away from 1000ml. Therefore, the actual water level was between 900-1000ml and close to 900ml. The maximum value of 900ml was taken as the current water level to reduce the error between the actual water level and ensure the accuracy of the water level result.

[0064] For another example, in the example where G26 and G22 simultaneously meet the first preset condition, if the mutual capacitance data corresponding to G26 does not meet the second preset condition, that is, the actual water level does not trigger the mutual capacitance detection water level 1000ml corresponding to G26. At this time, the self-capacitance detection water level of G26 is 800ml, and the self-capacitance detection water level of G22 is 700ml. The maximum value of 800ml can be taken as the current water level, or 800ml can be taken as the current water level within the range of 700ml-800ml. The self-capacitance detection water level of G26 and G21 was triggered, which means that the actual water level exceeded the self-capacitance detection water level of 800ml of G26 and exceeded the self-capacitance detection water level of 700ml of G22, but did not meet the second preset condition, indicating that the mutual capacitance detection water level of 1000ml of G26 was not reached. Therefore, the actual water level was between 800-900ml and close to 800ml. The maximum value of 800ml was taken as the current water level to reduce the error between the actual water level and ensure the accuracy of the water level result.

[0065] Through the above technical scheme, by combining the detection data of self-capacitance and mutual capacitance, the current water level can be judged more accurately. When the mutual capacitance data does not reach the preset water judgment threshold, the self-capacitance detection water level is used for supplementary judgment, which can reduce the misjudgment caused by single sensor error or water level fluctuation, and improve the accuracy of water level detection. The technical scheme provides two methods for determining the current water level: one is to directly take the maximum value of the self-capacitance detection water level of the target detection electrode that meets the conditions; the other is to determine the water level interval based on the self-capacitance detection water level corresponding to the target detection electrode, and take the maximum value of the interval. These two methods can be flexibly selected according to actual conditions to adapt to different water level detection needs. By combining multiple detection electrodes and corresponding thresholds for judgment, it can more reliably respond to various water level changes. Even if a detection electrode fails or has an error, the system can still make an accurate judgment through other detection electrodes and judgment logic, thereby enhancing the robustness of the system; by taking the maximum value of the self-capacitance detection water level of the target detection electrode that meets the conditions or the maximum value of the water level interval as the current water level, the result error caused by water level fluctuation or acquisition error can be reduced, and accurate water level detection results are guaranteed.

[0066] Step S103, if the self-capacitance data does not meet the first preset condition, determine the target detection electrode based on the pre-acquired mutual capacitance data of the detection electrodes, obtain the mutual capacitance detection water level corresponding to the target detection electrode, and determine the current water level.

[0067] In one embodiment of this specification, Figure 6 A water level detection flow chart provided in the embodiment of this specification when the first preset condition is not met, such as Figure 6 As shown, if the self-capacitance data does not meet the first preset condition, it means that the current water level is in a static state and there is no liquid level fluctuation. Therefore, the current water level can be detected by detecting the mutual capacitance data of the mutual capacitance detection electrodes in the detection electrodes.

[0068] Based on the mutual capacitance data of the detection electrode acquired in advance, the target detection electrode is determined, specifically including: obtaining the real-time mutual capacitance value of the detection electrode; judging the relationship between the real-time mutual capacitance value and the corresponding mutual capacitance no water judgment threshold, and determining the target detection electrode with the detection electrode whose real-time mutual capacitance value is less than the mutual capacitance no water judgment threshold.

[0069] In one embodiment of the present specification, if the liquid level is in a static state, the mutual capacitance value of each detection electrode is compared with the corresponding mutual capacitance no-water judgment threshold to determine the target detection electrode that touches the water. At this time, there may be two situations for the target detection electrode that touches the water, one is that it is completely covered by the water level, and the other is that it is partially covered by the water level. If the real-time mutual capacitance value is less than the no-water judgment threshold, it means that the corresponding detection electrode is in the water-touching state, that is, the target detection electrode is determined by the detection electrode less than the no-water judgment threshold, and the target detection electrode here is multiple electrodes.

[0070] Through the above technical scheme, by setting the mutual capacitance no water judgment threshold, slight changes in the water level can be detected more sensitively. When the real-time mutual capacitance value is less than the no water judgment threshold, it can be judged that the corresponding detection electrode has touched water, thereby responding to water level changes in time and improving the sensitivity of water level detection; it can accurately identify which detection electrodes have touched water, regardless of whether they are completely covered or partially covered by the water level. As long as their real-time mutual capacitance value is less than the no water judgment threshold, they can be determined to be in a water-touching state; by pre-setting the mutual capacitance no water judgment threshold and making comparative judgments during the real-time detection process, the water level detection process can be simplified and the detection efficiency can be improved.

[0071] In one embodiment of the present specification, when the real-time mutual capacitance values ​​obtained are not less than the corresponding mutual capacitance no-water judgment threshold, it is determined that the current water level is lower than the lowest detected water level of the water level detection area, the water level detection process is stopped and a water shortage signal is triggered. If the real-time mutual capacitance values ​​obtained are not less than the mutual capacitance no-water judgment threshold, it means that the actual water level has not triggered any detected water level in the water level detection area, that is, the current water level is lower than the lowest detected water level in the water level detection area. Figure 2 The 400ml water level shown means that the current water level is less than 400ml. At this time, the water level detection process should be stopped and the water shortage signal should be triggered.

[0072] Through the above technical scheme, by real-time monitoring of the mutual capacitance value and comparing it with the water-free judgment threshold, it is possible to quickly identify whether the current water level is lower than the minimum detection water level; once water shortage is confirmed, the water level detection process is stopped immediately and a water shortage signal is triggered so that users or related equipment can take timely measures, such as adding water or turning off the heater, etc., to avoid damage to the equipment or safety accidents due to water shortage; in applications such as liquid heaters, water shortage may cause serious consequences such as overheating, damage or even fire of the equipment. These potential safety hazards can be prevented by real-time monitoring and responding to the water shortage state; after confirming that the current water level is lower than the minimum detection water level, the water level detection process is stopped to reduce unnecessary energy consumption and computing resource consumption. At the same time, triggering a water shortage signal can remind users or related equipment to replenish water in time, thereby ensuring the normal operation of the equipment and extending its service life.

[0073] Obtaining the mutual capacitance detection water level corresponding to the target detection electrode to determine the current water level, specifically including: obtaining the first mutual capacitance detection water level and the second mutual capacitance detection water level of the target detection electrode, wherein the first mutual capacitance detection water level is less than the second mutual capacitance detection water level; determining whether the mutual capacitance data of the target detection electrode is higher than a preset mutual capacitance water judgment threshold, if so, determining the current water level according to the first mutual capacitance detection water level, otherwise determining the current water level according to the second mutual capacitance detection water level.

[0074] In one embodiment of the present specification, there may be multiple target detection electrodes determined in the above steps. For example, when the actual water level is within the range of 600-800ml, the real-time mutual capacitance values ​​of the mutual capacitance detection electrodes G29 and G25 are both less than the water-free judgment threshold. At this time, the first mutual capacitance detection water level and the second mutual capacitance detection water level corresponding to each target detection electrode are obtained. For example, the first mutual capacitance detection water level corresponding to G29 is 400ml, and the corresponding second mutual capacitance detection water level is 600ml. The first mutual capacitance detection water level corresponding to G25 is 600ml, and the corresponding second mutual capacitance detection water level is 800ml. According to the real-time mutual capacitance value of each target detection electrode and the corresponding mutual capacitance water judgment threshold, conditional judgment is performed to determine whether the real-time mutual capacitance value of each target detection electrode is higher than the mutual capacitance water judgment threshold. Since the mutual capacitance value gradually decreases with the increase of the water contact area of ​​the electrode, if the real-time mutual capacitance value is higher than the mutual capacitance water judgment threshold, it means that the maximum detection water level of this electrode sheet has not been triggered. Therefore, the current water level is determined according to the first mutual capacitance detection water level. On the contrary, if the real-time mutual capacitance value is not higher than the mutual capacitance water judgment threshold, it means that the maximum detection water level of this electrode sheet has been triggered, and the current water level is determined according to the maximum detection water level.

[0075] Continuing with the above example, when the actual water level is within the range of 600-800ml, the real-time mutual capacitance values ​​of the mutual capacitance detection electrodes G29 and G25 are both less than the no-water judgment threshold. The first mutual capacitance detection water level corresponding to G29 is 400ml, and the corresponding second mutual capacitance detection water level is 600ml. At this time, the real-time mutual capacitance value of G29 is not higher than the mutual capacitance water judgment threshold, that is, the current water level is determined based on the second mutual capacitance detection water level of 600ml corresponding to G29; at the same time, the first mutual capacitance detection water level corresponding to G25 is 600ml, and the corresponding second mutual capacitance detection water level is 800ml. At this time, the real-time mutual capacitance value of G25 is higher than the mutual capacitance water judgment threshold, indicating that the second mutual capacitance detection water level of 800ml is not triggered. Therefore, the first mutual capacitance detection water level of 600ml corresponding to G25 is used as the current water level. In the above example, the current water level obtained is 600ml. If there are multiple water level values ​​for the current water level obtained, the current water level is determined by the maximum water level value. In the above example, the current water level is 600ml. For another example, when the actual water level is in the range of 800-1000ml, the real-time mutual capacitance values ​​of the mutual capacitance detection electrodes G29, G25, and G26 are all less than the water-free judgment threshold. The first mutual capacitance detection water level corresponding to G29 is 400ml, and the corresponding second mutual capacitance detection water level is 600ml. At this time, the real-time mutual capacitance value of G29 is not higher than the mutual capacitance water judgment threshold, that is, the first current water level is determined according to the second mutual capacitance detection water level of 600ml corresponding to G29; at the same time, the first mutual capacitance detection water level corresponding to G25 is 600ml, and the corresponding second mutual capacitance detection water level is 600ml. The second mutual capacitance detection water level is 800 ml. At this time, the real-time mutual capacitance value of G25 is not higher than the mutual capacitance water judgment threshold, indicating that the second mutual capacitance detection water level 800 ml is triggered. Therefore, the second mutual capacitance detection water level 600 ml corresponding to G25 is used as the second current water level; the first mutual capacitance detection water level corresponding to G26 is 800 ml, and the corresponding second mutual capacitance detection water level is 1000 ml. At this time, the real-time mutual capacitance value of G26 is higher than the mutual capacitance water judgment threshold, indicating that the second mutual capacitance detection water level 1000 ml is not triggered. Therefore, the first mutual capacitance detection water level 800 ml corresponding to G26 is used as the third current water level. In the above example, there are multiple water level values ​​for the current water level obtained. At this time, the current water level is determined by the maximum water level value, that is, the third current water level 800 ml.

[0076] In addition to the above embodiments, the mutual capacitance detection water level corresponding to the target detection electrode is obtained to determine the embodiment corresponding to the current water level as follows: among the multiple target detection electrodes determined, according to the detection water level of each target detection electrode, the designated target detection electrode corresponding to the highest detection water level among the multiple target detection electrodes is determined. For example, the real-time mutual capacitance values ​​of the mutual capacitance detection electrodes G29, G25, and G26 are all less than the water-free judgment threshold. According to the detection water level corresponding to the above electrode sheet, G26 is determined as the designated target detection electrode, and it is determined whether the real-time mutual capacitance data of this designated target detection electrode is higher than the preset mutual capacitance water judgment threshold. If so, it means that the high detection water level of the designated target detection electrode is not triggered, that is, the current water level is determined by the first detection water level corresponding to the designated target detection electrode, which is the first detection water level 800ml corresponding to G26; if not, it means that the high detection water level of the designated target detection electrode is triggered, that is, the current water level is determined by the second detection water level corresponding to the designated target detection electrode, which is the second detection water level 1000ml corresponding to G26.

[0077] Through the above technical scheme, according to the two different detection water levels of the target detection electrode (the first mutual capacitance detection water level and the second mutual capacitance detection water level), and combined with the comparison of the real-time mutual capacitance value and the preset threshold, the current water level can be located more accurately, the accuracy of water level detection is improved, and the detection resolution is increased, so that the system can more finely reflect the changes in water level; when there are multiple target detection electrodes, the real-time mutual capacitance value and the corresponding detection water level of each electrode can be comprehensively considered to make a more robust water level judgment, and by introducing the mutual capacitance water judgment threshold, it can more flexibly respond to detection needs under different water level conditions; the above logical judgment method not only simplifies the water level detection process, but also improves the efficiency and accuracy of detection. Accurate water level detection can provide users with more accurate water level information and avoid problems such as heating interruption and liquid overflow due to misjudgment.

[0078] In one embodiment of the present specification, when the mutual capacitance data satisfies the second preset condition, the first mutual capacitance triggering moment corresponding to the mutual capacitance data satisfying the second preset condition is determined; the self-capacitance detection electrode whose self-capacitance detection water level is the same as the mutual capacitance detection water level is determined by the mutual capacitance detection water level corresponding to the mutual capacitance detection electrode; the real-time self-capacitance data of the verification self-capacitance detection electrode is obtained, and the second self-capacitance triggering moment corresponding to the first preset condition is determined to be satisfied by the real-time self-capacitance data; when the time difference between the first mutual capacitance triggering moment and the second self-capacitance triggering moment is within the preset error time, it is determined that the mutual capacitance data verification is passed. In other words, the mutual capacitance water level data is calibrated, that is, under the dynamic liquid level, when the mutual capacitance data of the target detection electrode such as G29 (corresponding to the water level of 600ml) satisfies the second condition, it is determined whether the self-capacitance data of G25 above G29 (corresponding to the water level of 600ml) satisfies the first preset condition at the same time or at different times (either in advance or in delay, limited to a shorter time) to achieve calibration.

[0079] Through the above technical solution, by calibrating the mutual capacitance water level data, that is, using the mutual capacitance detection electrode and the corresponding mutual capacitance detection water level, combined with the real-time self-capacitance data of the verification self-capacitance detection electrode, accurate calibration of the liquid level detection is achieved. By comparing the data of the mutual capacitance detection electrode and the verification self-capacitance detection electrode, possible errors can be discovered and corrected in time, thereby improving the accuracy of liquid level detection, and ensuring that the liquid level detection data remains high-precision under dynamic liquid levels, avoiding misjudgments caused by liquid surface fluctuations or sensor errors; by calibrating the mutual capacitance data, the reliability of the liquid level detection system can be further verified. When the mutual capacitance data and the verification self-capacitance data are consistent within the preset error time, it can be determined that the liquid level detection system is working normally, thereby enhancing the reliability of the system; accurate liquid level detection can provide users with more accurate water level information, avoiding problems such as heating interruption or liquid overflow caused by misjudgment.

[0080] In one embodiment of the present specification, in the process of determining the mutual capacitance data and the mutual capacitance water judgment threshold, the periodically collected mutual capacitance data is obtained. The type of water level change in the liquid container is determined by the change rule of the mutual capacitance data relative to the mutual capacitance water judgment threshold, wherein the water level change type includes water level rise, water level drop and water level fluctuation. Since the mutual capacitance value decreases to the mutual capacitance water judgment threshold during the liquid level rise process, if the change rule of the mutual capacitance data relative to the mutual capacitance water judgment threshold is that the mutual capacitance value decreases to the mutual capacitance water judgment threshold, the type of water level change in the liquid container is water level rise. If the change rule of the mutual capacitance data relative to the mutual capacitance water judgment threshold is that the mutual capacitance value increases to the mutual capacitance water judgment threshold, the type of water level change in the liquid container is determined to be water level drop. If the change rule of the mutual capacitance data relative to the mutual capacitance water judgment threshold is irregular increase or decrease, the type of water level change in the liquid container is determined to be water level fluctuation.

[0081] Through the above technical scheme, by periodically collecting mutual capacitance data, the water level changes in the liquid container can be monitored in real time, which can ensure that the equipment can operate safely and effectively according to the current water level status at any time; by comparing the collected mutual capacitance data with the preset mutual capacitance water judgment threshold, the rise, fall or fluctuation of the water level can be accurately judged, thereby improving the accuracy of detection; accurate judgment of the type of water level change helps to prevent dry burning caused by too low water level, and the risk of overflow or leakage caused by too high water level; by timely detecting water level fluctuations, safety hazards caused by violent shaking or instability of the liquid can also be prevented; based on the analysis of mutual capacitance data, intelligent detection of water level changes is realized, reducing the need for manual intervention and improving the degree of automation of the equipment; according to the type of water level change, the liquid heater can automatically adjust its working mode or issue a corresponding alarm, thereby improving the level of intelligence.

[0082] When the water level change type is water level fluctuation, the method also includes: judging whether a preset trigger signal is detected or whether the real-time water temperature in the liquid level container is less than a preset temperature threshold; if so, determining that the water level fluctuation means that the liquid container is in use, pausing water level detection until it is determined that the self-capacitance data does not meet the first preset condition and then restarting it; otherwise, determining that the water level fluctuation is a liquid surface boiling fluctuation caused by heating and boiling.

[0083] In one embodiment of the present specification, it is checked whether a preset trigger signal is received, where the trigger signal can be a trigger signal for putting the kettle back into the tea bar machine; at the same time, the system monitors the water temperature in the liquid level container and compares it with a preset temperature threshold. This temperature threshold is usually set to a safe temperature value before the liquid starts to boil, which is used to distinguish normal temperature changes during the heating process from extreme situations that may lead to misjudgment. When water level fluctuations are detected, first determine whether there is a trigger signal or whether the water temperature is lower than the preset temperature threshold. If any of the above conditions is met (i.e., there is a trigger signal or the water temperature is lower than the threshold), it indicates that the liquid container is in use. When it is determined that the liquid container is in use, the water level detection function is suspended to avoid false alarms or interference caused by user operations. When the self-capacitance data does not meet the first preset condition, that is, when the current liquid level returns to static, the water level detection function is reopened to resume normal monitoring of the liquid level. If when the water level fluctuation is detected, there is neither a trigger signal nor the water temperature is lower than the preset temperature threshold, it means that the water level fluctuation is caused by the boiling fluctuation of the liquid surface caused by heating and boiling.

[0084] Through the above technical scheme, by detecting the preset trigger signal (such as the action of lifting the kettle and putting it back into the tea bar machine) and the water temperature, the cause of the current water level fluctuation can be automatically identified, and subsequent operations can be performed under different causes. When the user operates the liquid container (such as adding or removing liquid), water level fluctuations are normal. By pausing the water level detection function, false alarms or interference caused by this can be avoided, thereby improving the accuracy and reliability of monitoring; by distinguishing between water level fluctuations caused by user operations and liquid surface fluctuations caused by heating and boiling, the heating process can be controlled more accurately.

[0085] When the water level fluctuation is a liquid surface boiling fluctuation caused by heating and boiling, the method also includes: obtaining the self-capacitance detection water level and the mutual capacitance detection water level corresponding to each target detection electrode, and when it is detected that the self-capacitance detection water level and / or the mutual capacitance detection water level reaches the preset first anti-overflow water level, starting the anti-overflow detection process; in the anti-overflow detection process, when it is detected that the self-capacitance detection water level and / or the mutual capacitance detection water level reaches the second anti-overflow water level, adjusting the heating parameters of the liquid heater based on the preset heating strategy.

[0086] In one embodiment of the present specification, when the water level fluctuation is a liquid surface boiling fluctuation caused by heating and boiling, two detection methods, self-capacitance and mutual capacitance, are used to respectively obtain the self-capacitance detection water level and mutual capacitance detection water level corresponding to each target detection electrode. These two detection methods can complement each other to improve the accuracy and reliability of liquid level detection. During the heating and boiling process, when it is detected that the self-capacitance detection water level and / or the mutual capacitance detection water level reaches a preset first anti-overflow water level, the anti-overflow detection process is started. The first anti-overflow water level is usually set to a relatively low liquid level value for early warning of possible overflow risks. During the anti-overflow detection process, the self-capacitance detection water level and / or the mutual capacitance detection water level are continuously monitored. When it is detected that these water levels reach the second anti-overflow water level, the heating parameters of the liquid heater are adjusted based on the preset heating strategy. The second anti-overflow water level is usually set to a higher liquid level value. Once this value is reached, the overflow risk increases significantly, so immediate measures need to be taken. The adjustment of the heating strategy here may include reducing the heating power, suspending heating, or taking other measures to slow down the rising speed of the liquid level. These measures are intended to prevent liquid overflow while ensuring safe operation.

[0087] Through the above technical solution, by real-time monitoring of the liquid level and starting the overflow prevention detection process when the preset overflow prevention water level is reached, it is possible to promptly detect and respond to potential liquid overflow risks, thereby effectively avoiding safety accidents caused by liquid overflow and greatly improving the safety of the equipment; combining the two detection methods of self-capacitance and mutual capacitance, it is possible to more accurately judge the liquid level changes and reduce equipment failures or misoperations caused by misjudgment, thereby enhancing stability and reliability; on the premise of ensuring safety, it is possible to intelligently adjust the heating parameters to avoid unnecessary heating interruptions and maintain heating efficiency, thereby providing users with a more stable and efficient heating experience, while reducing false alarms and interference, and improving user convenience and satisfaction.

[0088] Through the technical solution provided in the embodiments of this specification, in order to solve the problem that static liquid level cannot be accurately detected in the prior art, the embodiments of this specification realize water level detection under static liquid level by combining the judgment logic of self-capacitance data and mutual capacitance data. Even if the liquid level is in a static state, the target detection electrode can be determined by the pre-acquired mutual capacitance data or the real-time collected mutual capacitance data (after the dynamic liquid level is converted to static), and the current water level can be judged accordingly, thus breaking the limitation of relying on liquid level fluctuations; in addition, the dual detection mechanism of preliminary screening by self-capacitance and further confirmation by mutual capacitance reduces the error and failure risk that may be caused by a single detection method. By setting the first preset condition and the second preset condition, the current water level can be judged more accurately, reducing the problems of subsequent water inlet or heating process caused by inaccurate detection, and improving the safety and stability of the liquid heater; the prior art lacks an effective means to confirm the detection results, and the embodiments of this specification actually realize a secondary confirmation of the detection results by introducing the judgment logic of mutual capacitance data. When the self-capacitance data meets the first preset condition, the mutual capacitance data is further collected and judged. This double confirmation mechanism improves the reliability of the detection results. Through precise capacitance detection technology and logical judgment, it can adapt to the influence of different ambient temperatures and medium characteristics on the liquid level detection results to a certain extent. Through the setting of double detection mechanism and preset conditions, the interference of this influence on the normal operation and safety of the liquid heater is reduced. Accurate water level detection can provide users with more accurate water level information, avoid heating interruption, liquid overflow and other problems caused by misjudgment, improve user experience, and ensure the normal operation of the equipment and extend its service life by real-time monitoring of the water level and taking corresponding measures (such as stopping heating when there is a lack of water, issuing a warning when the water level is too high, etc.), thereby enhancing the safety and stability of the equipment.

[0089] Those skilled in the art will appreciate that the embodiments of this specification may be provided as methods, systems, or computer program products. Therefore, this specification may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, this specification may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0090] This specification is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of this specification. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0091] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0092] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process in the computer or other programmable device. Figure 1 A process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0093] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0094] The memory may include non-permanent storage in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM. The memory is an example of a computer-readable medium.

[0095] Computer readable media include permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. Information can be computer readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer readable media does not include temporary computer readable media (transitory media), such as modulated data signals and carrier waves.

[0096] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0097] The above description is only one or more embodiments of this specification and is not intended to limit this specification. For those skilled in the art, one or more embodiments of this specification may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of one or more embodiments of this specification shall be included in the scope of the claims of this specification.

Claims

1. A water level detection method for a liquid heater, the liquid heater comprising a liquid container and a water level detection area arranged on a side wall of the liquid container, wherein the water level detection area is provided with detection electrodes distributed in a longitudinally staggered manner, characterized in that: The method comprises: Receiving a water level detection instruction, acquiring self-capacitance data of the detection electrode; If the self-capacitance data satisfies the first preset condition, the corresponding detection electrode is determined as the target detection electrode, the mutual capacitance data of the target detection electrode is collected, and it is determined whether the mutual capacitance data satisfies the second preset condition, and the current water level is determined according to the determination result; If the self-capacitance data does not meet the first preset condition, a target detection electrode is determined based on the pre-acquired mutual capacitance data of the detection electrodes, and a mutual capacitance detection water level corresponding to the target detection electrode is acquired to determine the current water level.

2. A water level detection method for a liquid heater according to claim 1, characterized in that: Determining whether the mutual capacitance data satisfies a second preset condition, and determining the current water level according to the determination result, specifically includes: When the mutual capacitance data reaches a preset mutual capacitance water determination threshold, it is determined that a second preset condition is met, and the mutual capacitance detection water level corresponding to the target detection electrode is determined as the current water level; When the mutual capacitance data does not reach the preset mutual capacitance water judgment threshold, it is determined that the second preset condition is not met, the self-capacitance detection water level corresponding to the target detection electrode is obtained, and the current water level is determined based on the self-capacitance detection water level.

3. A water level detection method for a liquid heater according to claim 2, characterized in that: Determining the current water level based on the self-capacitance detection water level specifically includes: Determine a first target detection electrode and a second target detection electrode whose self-capacitance data satisfies a first preset condition, obtain self-capacitance detection water levels corresponding to the first target detection electrode and the second target detection electrode respectively, and determine the maximum value of the self-capacitance detection water levels as the current water level; Alternatively, a water level interval is determined based on the self-capacitance detection water level corresponding to the target detection electrode, and the current water level is determined by the maximum value of the water level interval.

4. A water level detection method for a liquid heater according to claim 2, characterized in that: In the process of determining the mutual capacitance data and the mutual capacitance water determination threshold, acquiring the periodically collected mutual capacitance data; The type of water level change in the liquid container is determined by the change pattern of the mutual capacitance data relative to the mutual capacitance water presence judgment threshold, wherein the water level change type includes water level rise, water level drop and water level fluctuation.

5. A water level detection method for a liquid heater according to claim 4, characterized in that: When the water level change type is water level fluctuation, the method further includes: Determine whether a preset trigger signal is detected or whether the real-time water temperature in the liquid level container is less than a preset temperature threshold. If so, determine that the water level fluctuation means that the liquid container is in use, and suspend water level detection until it is determined that the self-capacitance data does not meet the first preset condition and then restart; otherwise, determine that the water level fluctuation is a liquid surface boiling fluctuation caused by heating and boiling.

6. A water level detection method for a liquid heater according to claim 5, characterized in that: When the water level fluctuation is a liquid level boiling fluctuation caused by heating and boiling, the method further comprises: Acquire the self-capacitance detection water level and the mutual capacitance detection water level corresponding to each target detection electrode, and start the overflow prevention detection process when it is detected that the self-capacitance detection water level and / or the mutual capacitance detection water level reaches the preset first overflow prevention water level; In the anti-overflow detection process, when it is detected that the self-capacitance detection water level and / or the mutual capacitance detection water level reaches a second anti-overflow water level, the heating parameters of the liquid heater are adjusted based on a preset heating strategy.

7. A water level detection method for a liquid heater according to any one of claims 1 to 6, characterized in that: Determining a target detection electrode based on pre-acquired mutual capacitance data of the detection electrodes specifically includes: Obtaining a real-time mutual capacitance value of the detection electrode; The relationship between the real-time mutual capacitance value and the corresponding mutual capacitance no-water judgment threshold is determined, and the target detection electrode is determined by the detection electrode whose real-time mutual capacitance value is less than the mutual capacitance no-water judgment threshold.

8. A water level detection method for a liquid heater according to claim 7, characterized in that: Obtaining the mutual capacitance detection water level corresponding to the target detection electrode to determine the current water level, specifically including: Acquire a first mutual capacitance detection water level and a second mutual capacitance detection water level of the target detection electrode, wherein the first mutual capacitance detection water level is less than the second mutual capacitance detection water level; Determine whether the mutual capacitance data of the target detection electrode is higher than a preset mutual capacitance water judgment threshold. If so, determine the current water level according to the first mutual capacitance detection water level. Otherwise, determine the current water level according to the second mutual capacitance detection water level.

9. The water level detection method for a liquid heater according to claim 7, characterized in that: The method further comprises: When the acquired real-time mutual capacitance values ​​are not less than the corresponding mutual capacitance water-free judgment threshold, it is determined that the current water level is lower than the lowest detected water level of the water level detection area, the water level detection process is stopped and a water shortage signal is triggered.

10. The water level detection method for a liquid heater according to claim 1, characterized in that: The determination process of the self-capacitance data and the first preset condition specifically includes: Collecting the real-time self-capacitance value of the detection electrode, determining the difference according to the real-time self-capacitance value and the preset real-time baseline value of the corresponding self-capacitance change following baseline, and determining the self-capacitance data of the detection electrode according to the absolute value of the difference; When the self-capacitance data is greater than a preset self-capacitance water-touch judgment threshold, it is determined that the self-capacitance data of the detection electrode meets the first preset condition and is determined to be a dynamic liquid level; When the self-capacitance data is not greater than a preset self-capacitance determination threshold, it is determined that the self-capacitance data of the detection electrode does not satisfy the first preset condition and is determined to be a static liquid level.

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