Solenoid valve state monitoring device and method

Abstract

The invention relates to the technical field of electromagnetic valve internal resistance adjustment, in particular to an electromagnetic valve state monitoring device and method.The electromagnetic valve state monitoring device comprises a controller, an RC filter circuit, a sliding filter circuit, a drive circuit and an ADC sampling circuit, and the controller is connected with the RC filter circuit, the drive circuit and the ADC sampling circuit; the ADC sampling circuit is respectively connected with the driving circuit and the sliding filter circuit; wherein the sliding filter circuit maintains three historical data thresholds to form a sliding window, new sampling data is compared with each historical value in the window, sampling noise is eliminated, then the new sampling data is transmitted to the controller through the ADC sampling circuit, the controller collects the sampling data through the ADC sampling circuit and carries out data preprocessing, and therefore the on-off state of the electromagnetic valve is judged; according to the invention, the transient response characteristics of the driving voltage of the electromagnetic valve are fully utilized, the dynamic model solution and the adaptive filtering algorithm are matched, the effective signal reflecting the internal resistance change is separated, and high-precision state recognition and fault early warning are realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of solenoid valve internal resistance regulation, and particularly relates to a solenoid valve state monitoring device and method. Background Art

[0002] In kitchen gas equipment, the solenoid valve is the core actuator for controlling the gas on-off. The accurate monitoring of its working state is directly related to the safe operation and energy efficiency management of the gas system. The existing technology mainly indirectly infers the valve opening and closing state by analyzing the changes in electromagnetic characteristic parameters during the solenoid valve driving process. Its technical principle is based on the physical correlation between the dynamic current waveform generated when the solenoid valve coil is energized and the mechanical displacement of the valve core: when the solenoid valve is in the open state, the valve core is attracted, resulting in a decrease in the air gap of the coil magnetic circuit and a significant increase in the inductance, which causes the current rise rate to slow down and finally tend to a steady-state value; while in the closed state, the valve core is released, the air gap of the magnetic circuit is restored, the inductance decreases sharply, and the current waveform shows a rapid decay characteristic. This current waveform change rule provides a theoretical basis for valve state monitoring.

[0003] However, the existing technical solutions face multiple technical bottlenecks in practical engineering applications: First, traditional monitoring systems generally use independent current detection modules, and a high-precision current sensor needs to be connected in series in the solenoid valve drive circuit. This solution not only increases the hardware cost and system complexity but also may affect the original electrical characteristics of the solenoid valve due to the parasitic parameters introduced by the sensor, especially facing space layout conflicts in the design of compact gas equipment control boards. Second, the existing fixed threshold judgment mechanism has inherent defects. There are batch process deviations in the coil internal resistance during the manufacturing process of the solenoid valve, and the aging drift caused by long-term operation will change the inductance parameters. At the same time, the voltage reference drift caused by the working temperature range further weakens the accuracy of the threshold judgment. More prominently, the single current sampling mechanism is vulnerable to random noises such as power supply ripple, electromagnetic interference, and mechanical vibration. In a complex electromagnetic environment, the state misjudgment rate of the traditional solution is significantly higher than the safety standard requirements.

[0004] The above technical defects seriously restrict the large-scale application of solenoid valve state monitoring technology in kitchen gas equipment, and there is an urgent need for a breakthrough in technology to solve the contradictions among cost, reliability, and environmental adaptability. Summary of the Invention

[0005] In order to overcome the deficiencies of the existing technology, the present application provides a solenoid valve state monitoring device and method, aiming to solve problems such as valve response delay and gas leakage risk caused by impedance mismatch in the existing technology.

[0006] The technical means adopted by the present invention to solve its technical problems is: a solenoid valve state monitoring device, which is improved in that it includes: a controller, an RC filtering circuit, a sliding filtering circuit, a driving circuit, and an ADC sampling circuit. The controller is respectively connected to the RC filtering circuit, the driving circuit, and the ADC sampling circuit. The ADC sampling circuit is respectively connected to the driving circuit and the sliding filtering circuit; wherein, The sliding filtering circuit forms a sliding window by maintaining three historical data thresholds. The new sampling data is compared with each historical value in the window, and after eliminating the sampling noise, it is transmitted to the controller through the ADC sampling circuit. The controller collects sampling data through the ADC sampling circuit and performs data preprocessing, so as to judge the on-off state of the solenoid valve.

[0007] In the above technical solution, the model of the controller is SC8F6790. The RC filtering circuit includes a voltage stabilizing diode DM4, a resistor R2, a capacitor CQ2, a resistor R15, and a triode Q3. Among them, The 12th pin of the controller is connected to one end of the voltage stabilizing diode DM4, the resistor R2, and the capacitor CQ2, and the other end of the voltage stabilizing diode DM4 is grounded; The other ends of the resistor R2 and the capacitor CQ2 are connected to the base of the triode Q3 and one end of the resistor R15, and the emitter of the triode Q3 and the other end of the resistor R15 are grounded.

[0008] In the above technical solution, the driving circuit includes a voltage stabilizing diode DM3, a resistor R7, and a capacitor CQ1. Among them, The 8th pin of the controller is connected to one end of the voltage stabilizing diode DM3, the resistor R7, and the capacitor CQ1, and the other end of the voltage stabilizing diode DM3 is grounded; The other ends of the resistor R7 and the capacitor CQ1 are connected to the ADC sampling circuit.

[0009] In the above technical solution, the ADC sampling circuit includes a triode Q4, a resistor RD1, a resistor RD2, a resistor RD3, and a resistor R18. Among them, The base of the triode Q4 is connected to the other end of the resistor R7, the capacitor CQ1, and one end of the resistor R18, and the other end of the resistor R18 is grounded; The emitter of the triode Q4 is connected to one end of the resistor RD1, the resistor RD2, and the resistor RD3. The other ends of the resistor RD1 and the resistor RD2 are grounded, and the other end of the resistor RD3 is connected to the 6th pin of the controller; The collector of the triode Q4 is connected to the sliding filtering circuit.

[0010] In the above technical solution, the sliding filter circuit includes a fuse F1 and a diode D3. Among them, One end of the fuse F1 is connected to the negative electrode of the diode D3, and the other end of the fuse F1 and the positive electrode of the diode D3 are connected to the collector of the triode Q4; The collector of the triode Q4 is also connected to the controller for reading three historical data values stored in the controller.

[0011] The technical means adopted by the present invention to solve its technical problems is: a method for monitoring the state of a solenoid valve, and the method includes the following steps: Step 1: Read data from the memory and detect whether it is a null value; if so, drive the valve to perform a valve closing operation to store the valve opening and closing voltage values; if not, assign the memory data to the voltage values V 开 、V 关 under the valve opening and closing states, and calculate the internal resistances corresponding to the voltage values V 开 、V 关 under the valve opening and closing states; Step 2: Periodically detect the change of the voltage value, and convert it into a comparison with the real-time internal resistance and the internal resistances corresponding to the voltage values V 开 、V 关 under the valve opening and closing states to determine whether the real-time internal resistance exceeds the set range; Step 3: If the real-time internal resistance does not exceed the set range, return to Step 2; if the real-time internal resistance exceeds the set range, further determine whether the real-time internal resistance approaches 0 or far exceeds the maximum value of the valve internal resistance; Step 4: If the real-time internal resistance approaches 0 or far exceeds the maximum value of the valve internal resistance, the valve fails; if the real-time internal resistance does not approach 0 or far exceed the maximum value of the valve internal resistance, further determine whether the same change trend appears three times in a row; Step 5: If the real-time internal resistance does not show the same change trend three times in a row, compare the data with the intermediate value of the maximum and minimum extreme values, and output the valve state as closed or open; if the real-time internal resistance shows the same change trend three times in a row, the valve state changes, output the valve state as closed or open, and store the updated voltage value.

[0012] In the above technical solution, Step 2 includes: Step 21: Initialize parameters, and the parameters include a sampling frequency, a threshold, and an internal resistance coefficient; Step 22: Detect and collect the valve detection voltage value, and at the same time perform data filtering and power supply voltage compensation; Step 23: Calculate the real-time internal resistance and determine whether the real-time internal resistance is within the set range of the internal resistance values corresponding to the valve opening and closing; Step 24: If the real-time internal resistance is within the set range of the internal resistance values corresponding to opening and closing the valve, return to Step 22; if the real-time internal resistance is not within the set range of the internal resistance values corresponding to opening and closing the valve, it indicates that the internal resistance has deviated from the original parameters, and it is determined that the valve needs to compensate for the internal resistance and update and save the internal resistance coefficient.

[0013] In the above technical solution, the real-time internal resistance in Step 22 is calculated by dynamically collecting voltage and current signals and fitting the data in the linear region using the least squares method: ; where, R 实时 is the equivalent DC internal resistance after removing the inductance effect; V(t i ) is the steady-state sampled voltage data after removing the transient process; I(t i ) is the steady-state sampled current data after removing the transient process; n is the number of sampling points within a single steady-state period.

[0014] The beneficial effects of the present invention are: This application abandons the traditional method in the prior art that relies on a current detection module or a fixed voltage threshold comparison. It makes full use of the transient response characteristics of the solenoid valve drive voltage, combines with a dynamic model calculation and an adaptive filtering algorithm to separate the effective signal reflecting the internal resistance change, and realizes high-precision state recognition and fault warning; and through a dynamic voltage threshold adjustment and trend continuous confirmation mechanism, it realizes a reliable judgment of the solenoid valve state. The innovation point lies in abandoning the fixed threshold comparison, adopting an adaptive decision driven by historical data, combining multi-stage filtering and fault overrun detection, and realizing high-precision state recognition on low-cost hardware. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a structural block diagram of a solenoid valve state monitoring device shown in an embodiment of the present invention; Figure 2 is a circuit structural diagram of a solenoid valve state monitoring device shown in an embodiment of the present invention; Figure 3 is a controller type diagram shown in an embodiment of the present invention; Figure 4 is a flowchart of a solenoid valve state monitoring method shown in an embodiment of the present invention; Figure 5 is an internal resistance range judgment flowchart shown in an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0016] The present invention will be further described below with reference to the drawings and embodiments.

[0017] The concept, specific structure and technical effects of the present invention will be clearly and completely described below in conjunction with the embodiments and the accompanying drawings to fully understand the purpose, features and effects of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, other embodiments obtained by those skilled in the art without creative efforts shall fall within the scope of protection of the present invention. In addition, all connection / linkage relationships involved in the patent do not simply refer to the direct connection of components, but refer to the formation of a more optimal connection structure by adding or reducing connection accessories according to specific implementation situations. The various technical features in the present invention can be interactively combined without conflicting with each other.

[0018] As Figure 1 shown, the present application provides a solenoid valve state monitoring device, including a controller 1, an RC filter circuit 2, a sliding filter circuit 3, a driving circuit 4 and an ADC sampling circuit 5. The controller 1 is respectively connected to the RC filter circuit 2, the driving circuit 4 and the ADC sampling circuit 5. The ADC sampling circuit 5 is respectively connected to the driving circuit 4 and the sliding filter circuit 3; wherein, The sliding filter circuit 3 forms a sliding window by maintaining three historical data thresholds. The new sampling data is compared with each historical value in the window, and after eliminating the sampling noise, it is transmitted to the controller through the ADC sampling circuit. The controller 1 collects sampling data through the ADC sampling circuit and performs data preprocessing to judge the on / off state of the solenoid valve.

[0019] In a possible implementation manner, as Figures 2-3 shown, the model of the controller 1 is SC8F6790. The RC filter circuit 2 includes a zener diode DM4, a resistor R2, a capacitor CQ2, a resistor R15 and a triode Q3. Among them, The 12th pin of the controller is connected to one end of the zener diode DM4, the resistor R2 and the capacitor CQ2, and the other end of the zener diode DM4 is grounded; The other ends of the resistor R2 and the capacitor CQ2 are connected to the base of the triode Q3 and one end of the resistor R15, and the emitter of the triode Q3 and the other end of the resistor R15 are grounded.

[0020] In a possible implementation manner, continue to refer to Figure 2 shown, the driving circuit 4 includes a zener diode DM3, a resistor R7 and a capacitor CQ1. Among them, The 8th pin of the controller is connected to one end of the zener diode DM3, the resistor R7 and the capacitor CQ1, and the other end of the zener diode DM3 is grounded; The other ends of the resistor R7 and the capacitor CQ1 are connected to the ADC sampling circuit.

[0021] In a possible implementation, continue to refer to Figure 2 As shown, the ADC sampling circuit 5 includes a triode Q4, a resistor RD1, a resistor RD2, a resistor RD3, and a resistor R18, where The base of the triode Q4 is connected to the other ends of the resistor R7, the capacitor CQ1, and one end of the resistor R18, and the other end of the resistor R18 is grounded; The emitter of the triode Q4 is connected to one ends of the resistor RD1, the resistor RD2, and the resistor RD3. The other ends of the resistor RD1 and the resistor RD2 are grounded, and the other end of the resistor RD3 is connected to the 6th pin of the controller; The collector of the triode Q4 is connected to the sliding filter circuit.

[0022] In a possible implementation, continue to refer to Figure 2 As shown, the sliding filter circuit 3 includes a fuse F1 and a diode D3, where One end of the fuse F1 is connected to the negative electrode of the diode D3, and the other end of the fuse F1 and the positive electrode of the diode D3 are connected to the collector of the triode Q4; The collector of the triode Q4 is also connected to the controller for reading three historical data values stored in the controller.

[0023] The working principle of the entire circuit is as follows: The sampling noise is eliminated through the RC filter circuit and the sliding filter circuit respectively. The controller's 8th pin is used to enable and output a high level, so that the triode Q4 conducts, and the solenoid valve drive voltage is collected through the ADC sampling circuit; Three historical data values are used to form a sliding window, and the new data is compared with each historical value in the window to eliminate the single-sampling noise.

[0024] This application abandons the traditional method that relies on the current detection module or the fixed voltage threshold comparison, makes full use of the transient response characteristics of the solenoid valve drive voltage, and combines the dynamic model calculation and the adaptive filtering algorithm to separate the effective signal reflecting the internal resistance change, so as to realize high-precision state recognition and fault warning.

[0025] As Figure 4 shown, this application also provides a method for monitoring the state of a solenoid valve. The method includes the following steps: Step 1: Read data from the memory and detect whether it is a null value; if so, drive the valve to perform a valve closing operation to store the valve opening and closing voltage values; if not, assign the memory data to the voltage values V 开 、V 关, and calculate the voltage values V 开 and V 关 corresponding internal resistance; Specifically, the calculation of the internal resistance of the opening voltage is as shown in the following formula (1): ; where R 开 is the coil internal resistance in the valve opening state; V 开 is the applied opening voltage, and the typical value is the rated working voltage; I 开 is the opening current measured under steady state; The calculation of the internal resistance of the closing voltage is as shown in the following formula (2): ; where R 关 is the coil internal resistance in the valve closing state; V 关 is the applied reverse closing voltage, usually 50%-80% of the rated voltage; I 开 is the closing current measured under steady state.

[0026] Step 2: Periodically detect the change of the voltage value, and convert it into the real-time internal resistance and compare it with the internal resistance corresponding to the voltage values V 开 and V 关 corresponding to judge whether the real-time internal resistance exceeds the set range; In an exemplary embodiment, as Figure 5 shown, the step 2 includes the following steps: Step 21: Initialize the parameters, and the parameters include the sampling frequency, the threshold value, and the internal resistance coefficient; Step 22: The valve detects the voltage value and collects it, and at the same time performs data filtering and power supply voltage compensation; Step 23: Calculate the real-time internal resistance, and judge whether the real-time internal resistance is within the set range of the internal resistance values corresponding to the opening and closing valves; Step 24: If the real-time internal resistance is within the set range of the internal resistance values corresponding to the opening and closing valves, return to step 22; if the real-time internal resistance is not within the set range of the internal resistance values corresponding to the opening and closing valves, it means that the internal resistance has deviated from the original parameters, and it is determined that the valve needs to compensate the internal resistance and update and save the internal resistance coefficient.

[0027] Step 3: If the real-time internal resistance does not exceed the set range, return to step 2; if the real-time internal resistance exceeds the set range, further judge whether the real-time internal resistance approaches 0 or far exceeds the maximum value of the valve internal resistance; Step 4: If the real-time internal resistance approaches 0 or far exceeds the maximum value of the valve internal resistance, the valve fails; if the real-time internal resistance does not approach 0 or far exceed the maximum value of the valve internal resistance, further judge whether the same change trend appears three times in a row; Step 5: If the real-time internal resistance does not show the same changing trend three times consecutively, compare the data with the median value of the maximum and minimum extreme values, and output the valve state as closed or open; if the real-time internal resistance shows the same changing trend three times consecutively, the valve state changes, output the valve state as closed or open, and store the updated voltage value.

[0028] Through the above embodiments, in the data acquisition stage of the present application, a three-stage filtering is formed by using a sliding window + median filtering + mutation suppression, which greatly reduces the noise in the data acquisition process; then the present application designs a unique trend continuous confirmation mechanism, that is, the state change prompt will be triggered only when there are 6 consecutive times with the same trend. Through continuous trend confirmation several times, the false trigger rate of pulse noise interference is reduced.

[0029] Moreover, in the algorithm of the present application, a threshold range can be set to support solenoid valves with internal resistance differences not exceeding a certain range, which greatly improves the compatibility of cross-brand devices; at the same time, by automatically updating and storing the extreme values, the false judgment rate caused by aging of the first selected year is reduced.

[0030] In a possible implementation, in step 23, the real-time internal resistance is calculated by dynamically collecting voltage and current signals and fitting the linear region data by the least squares method. The calculation formula is as shown in (3) below: (3); Where, R 实时 is the equivalent DC internal resistance after removing the inductance effect; V(t i ) is the steady-state sampling voltage data after removing the transient process; I(t i ) is the steady-state sampling current data after removing the transient process; n is the number of sampling points in a single steady-state period.

[0031] By extracting the linear region data and fitting it by the least squares method, the influence of the non-linear region (such as the polarization effect at high current or the noise interference at low current) on the measurement result can be avoided, thereby significantly improving the calculation accuracy of the internal resistance; the least squares method can more accurately fit the data trend by minimizing the sum of squared errors, reduce the influence of random errors and measurement noise, and ensure the reliability of the internal resistance calculation result.

[0032] The above is a specific description of the preferred embodiments of the present invention, but the present invention is not limited to the described embodiments. Those skilled in the art can make various equivalent deformations or substitutions without departing from the spirit of the present invention, and these equivalent deformations or substitutions are all included within the scope defined by the claims of the present application.

Claims

1. A solenoid valve status monitoring device, characterized in that: It includes a controller, an RC filter circuit, a sliding filter circuit, a drive circuit and an ADC sampling circuit, wherein the controller is connected to the RC filter circuit, the drive circuit and the ADC sampling circuit respectively, and the ADC sampling circuit is connected to the drive circuit and the sliding filter circuit respectively; wherein, The sliding filter circuit forms a sliding window by maintaining three historical data thresholds, and compares the new sampled data with each historical value in the window, and transmits it to the controller through the ADC sampling circuit after eliminating the sampling noise. The controller collects sampling data through the ADC sampling circuit and performs data preprocessing, thereby determining the switch state of the solenoid valve.

2. The solenoid valve state monitoring device according to claim 1, characterized in that: The controller model is SC8F6790, and the RC filter circuit includes a voltage stabilizing diode DM4, a resistor R2, a capacitor CQ2, a resistor R15, and a transistor Q3, wherein: The 12th pin of the controller is connected to the voltage stabilizing diode DM4, the resistor R2 and one end of the capacitor CQ2, and the other end of the voltage stabilizing diode DM4 is grounded; The other ends of the resistor R2 and the capacitor CQ2 are connected to the base of the transistor Q3 and one end of the resistor R15 , and the emitter of the transistor Q3 and the other end of the resistor R15 are grounded.

3. The solenoid valve state monitoring device according to claim 2, characterized in that: The driving circuit includes a voltage stabilizing diode DM3, a resistor R7 and a capacitor CQ1, wherein: The 8th pin of the controller is connected to the voltage stabilizing diode DM3, the resistor R7 and one end of the capacitor CQ1, and the other end of the voltage stabilizing diode DM3 is grounded; The other ends of the resistor R7 and the capacitor CQ1 are connected to the ADC sampling circuit.

4. The solenoid valve state monitoring device according to claim 3, characterized in that: The ADC sampling circuit includes a transistor Q4, a resistor RD1, a resistor RD2, a resistor RD3 and a resistor R18, wherein: The base of the transistor Q4 is connected to the resistor R7, the other end of the capacitor CQ1 and one end of the resistor R18, and the other end of the resistor R18 is grounded; The emitter of the transistor Q4 is connected to one end of the resistor RD1, the resistor RD2, and the resistor RD3, the other ends of the resistor RD1 and the resistor RD2 are grounded, and the other end of the resistor RD3 is connected to the sixth pin of the controller; The collector of the transistor Q4 is connected to the sliding filter circuit.

5. The solenoid valve state monitoring device according to claim 4, characterized in that: The sliding filter circuit includes a fuse F1 and a diode D3, wherein: One end of the fuse F1 is connected to the cathode of the diode D3, and the other end of the fuse F1 and the anode of the diode D3 are connected to the collector of the transistor Q4; The collector of the transistor Q4 is also connected to the controller for reading three historical data values ​​stored in the controller.

6. A solenoid valve state monitoring method applied to claim 1, characterized in that: The method comprises: Step 1: Read data from the memory and check whether it is a null value; if so, drive the valve to close once to store the valve opening and closing voltage values; if not, assign the memory data to the voltage value V when the valve is open or closed. 开 、V 关 , and calculate the voltage value V when the valve is switched 开 、V 关 The corresponding internal resistance; Step 2: Periodically detect the voltage value change and convert it into the real-time internal resistance and the voltage value V under the valve switch state 开 、V 关 The corresponding internal resistance is compared to determine whether the real-time internal resistance exceeds the set range; Step 3: If the real-time internal resistance does not exceed the set range, return to step 2; if the real-time internal resistance exceeds the set range, further determine whether the real-time internal resistance is close to 0 or far exceeds the maximum value of the valve internal resistance; Step 4: If the real-time internal resistance approaches 0 or far exceeds the maximum value of the valve internal resistance, the valve fails; if the real-time internal resistance does not approach 0 or far exceeds the maximum value of the valve internal resistance, further determine whether the same change trend is presented for three consecutive times; Step 5: If the real-time internal resistance does not show the same change trend three times in a row, the data is compared with the middle value of the maximum and minimum extreme values, and the valve state is output as closed or open; if the real-time internal resistance shows the same change trend three times in a row, the valve state changes, the valve state is output as closed or open, and the updated voltage value is stored.

7. A solenoid valve state monitoring method according to claim 6, characterized in that: The step 2 comprises: Step 21: Initialize parameters, including sampling frequency, threshold value and internal resistance coefficient; Step 22: The valve detects and collects the voltage value, and performs data filtering and power supply voltage supplementation at the same time; Step 23: Calculate the real-time internal resistance and determine whether the real-time internal resistance is within the set range of the corresponding internal resistance values ​​of the open and closed valves; Step 24: If the real-time internal resistance is within the setting range of the internal resistance values ​​corresponding to the open and closed valves, return to step 22; if the real-time internal resistance is not within the setting range of the internal resistance values ​​corresponding to the open and closed valves, it means that the internal resistance has deviated from the original parameters, and it is determined that the valve needs to compensate for the internal resistance and update and save the internal resistance coefficient.

8. A solenoid valve state monitoring method according to claim 7, characterized in that: In step 22, the real-time internal resistance is calculated by dynamically collecting voltage and current signals and fitting the linear region data using the least squares method: ； Among them, R 实时 is the equivalent DC internal resistance after removing the inductance effect; V(t i ) is the steady-state sampling voltage data after removing the transient process; I (t i ) is the steady-state sampling current data after removing the transient process; n is the number of sampling points in a single steady-state cycle.

Images