An anti-interference combustible gas alarm control system and method

Abstract

The present invention relates to the field of gas detection technology, and in particular to an anti-interference combustible gas alarm control system and method. The system includes a data acquisition module, the data acquisition module includes a combustible gas detector and a signal collector, the combustible gas detector is connected to the signal collector; a data processing module, the data processing module includes a single-chip microcomputer and a wireless adapter, the single-chip microcomputer is connected to the wireless adapter, and the wireless adapter uploads the processed data of the single-chip microcomputer to a host computer; an interference analysis module, the interference analysis module includes an anti-interference circuit, and the anti-interference circuit performs anti-interference processing on the analog signal transmitted by the signal collector; a power supply module, the power supply module includes a main power supply, a backup power supply and a power management circuit. The technical solution of the present invention can reduce the interference of the electromagnetic field generated by the power line inside the system on the analog signal and increase the accuracy of combustible gas detection.

Description

Technical Field

[0001] The present invention relates to the technical field of gas detection, and in particular to an anti-interference combustible gas alarm control system and method. Background Art

[0002] In the prior art, the gas alarm control system can perform real-time detection of flammable or toxic gases in the air, and issue an alarm in time when a harmful gas leak is detected. The gas alarm control system has spread to all walks of life and has become a very common product on the market. At present, the distribution of gas alarm control systems mainly adopts two methods: wired distribution and wireless distribution. For wired distribution, as the working environment becomes more and more complex, the installation location of the gas alarm controller is restricted and the wiring distribution is complicated. In addition, wired connections may sometimes require the distribution of lines within the building, which causes it to be subject to some physical obstacles. The main defect of wireless distribution is poor anti-interference ability, especially the power supply noise and electromagnetic field generated by the internal power cord will interfere with the analog signal, which can easily lead to unstable signal transmission.

[0003] For example, the invention patent with application number CN202311412557.1 discloses an online monitoring system for portable gas alarms based on the Internet of Things, and analyzes the anti-interference evaluation coefficient of portable gas alarms. However, during the data transmission and processing process, it will inevitably be affected by the electromagnetic interference of its own lines. At this stage, an anti-interference combustible gas alarm control system and method are needed. Summary of the invention

[0004] In order to solve the problem of poor anti-interference performance of a wireless gas alarm control system, the present invention provides an anti-interference combustible gas alarm control system and method.

[0005] In the first aspect, the present invention provides an anti-interference combustible gas alarm control system, which adopts the following technical solution:

[0006] An anti-interference combustible gas alarm control system, comprising:

[0007] A data acquisition module, wherein the data acquisition module comprises a combustible gas detector and a signal collector, and the combustible gas detector is connected to the signal collector;

[0008] A data processing module, wherein the data processing module includes a single-chip microcomputer and a wireless adapter, wherein the single-chip microcomputer is connected to the wireless adapter, and the wireless adapter uploads the processing data of the single-chip microcomputer to the host computer;

[0009] An interference analysis module, wherein the interference analysis module comprises an anti-interference circuit, wherein the anti-interference circuit is connected to the single-chip microcomputer, and the anti-interference circuit performs anti-interference processing on the analog signal transmitted by the signal collector;

[0010] A power supply module, wherein the power supply module comprises a main power supply, a backup power supply and a power supply management circuit, wherein the power supply management circuit is connected to the main power supply and the backup power supply respectively.

[0011] Furthermore, the combustible gas detector includes a gas sensor, a thermal resistor heater and an activated carbon filter membrane, the activated carbon filter membrane is sealed and connected to the bottom of the thermal resistor heater, and the gas sensor is nested in the periphery of the thermal resistor heater.

[0012] Furthermore, the single chip microcomputer is connected to the wireless adapter, comprising the step of connecting a signal output terminal of the single chip microcomputer to a signal input terminal of the wireless adapter using an SPL communication interface.

[0013] Furthermore, the anti-interference circuit includes a signal filtering circuit, a power filtering circuit, a power switch and a power chip. The signal output end of the signal filtering circuit is connected to the signal input end of the microcontroller, the power chip is connected to the power filtering circuit through the power switch, and the output end of the power filtering circuit is connected to the voltage input end of the microcontroller.

[0014] Furthermore, the output end of the power filter circuit is connected to the voltage input end of the single-chip microcomputer, including the power chip connected to the gate of the power switch, the output end of the power filter circuit is connected to the source of the power switch, and the drain of the power switch is connected to the voltage input end of the single-chip microcomputer.

[0015] Furthermore, the signal filtering circuit includes a differential amplifier, a digital filter and a signal processing chip. The signal processing chip is connected to a signal collector for receiving concentration information detected by a gas sensor. The differential amplifier is respectively connected to the digital filter and the signal processing chip.

[0016] Furthermore, the power supply filter circuit includes a first voltage stabilizing capacitor, a second voltage stabilizing capacitor, an EMI filter and a voltage stabilizer, the input end of the voltage stabilizer is connected to the voltage output end of the power management circuit, the output end of the voltage stabilizer is connected to the EMI filter, and the first voltage stabilizing capacitor is connected in series with the output end of the voltage stabilizer after being connected in parallel with the second voltage stabilizing capacitor.

[0017] In a second aspect, an anti-interference combustible gas alarm control method includes:

[0018] Place the control system in a shielded box with a certain concentration of combustible gas to obtain the concentration information detected by the combustible gas detector;

[0019] The concentration information detected by the combustible gas detector is used as the characteristic variable, and the concentration information received by the single-chip microcomputer is used as the result variable to calculate the interference coefficient;

[0020] The output power of the power switch is adjusted according to the interference coefficient to control the concentration error to be less than the set threshold.

[0021] Furthermore, the calculation of the interference coefficient includes constructing a scatter plot with the characteristic variable as the X-axis and the result variable as the Y-axis, using the scatter plot to screen data and remove data with large deviations, and calculating the interference coefficient based on the screened data. The formula for calculating the interference coefficient is:

[0022] ,

[0023] Among them, R represents the interference coefficient, i represents the i-th data sample, x represents the feature variable, y represents the result variable, and n represents the number of samples.

[0024] Furthermore, the output power of the power switch is adjusted according to the interference coefficient, including taking the minimum gate voltage when the power switch is turned on and the gate voltage when the power switch is conductively saturated as a value range, stepping in the range of 0.1V to 0.3V, and determining the output power of the power switch when the interference coefficient is closest to 1.

[0025] In summary, the present invention has the following beneficial technical effects:

[0026] 1. The anti-interference combustible gas alarm control system of the present invention effectively reduces the impact of electromagnetic interference on the combustible gas alarm system, effectively improves the stability and reliability of the system, ensures that the system can accurately detect and alarm the presence of combustible gas, reduces the probability of false alarms or non-alarms, and takes timely measures to deal with them, thereby avoiding potential safety risks and accidents.

[0027] 2. The anti-interference combustible gas alarm control method of the present invention can reduce the energy consumption and maintenance cost of the system through the anti-interference technology of the control method. By effectively suppressing interference signals and optimizing system design, the switching times of the power switch and the energy consumption of the system can be reduced. At the same time, reducing false alarms and false alarms can avoid unnecessary maintenance and manual intervention, reducing the operating cost of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is the overall circuit diagram of a filter circuit in an anti-interference combustible gas alarm control system according to Example 1 of the present invention.

[0029] Figure 2 This is a power supply filter circuit diagram of an anti-interference combustible gas alarm control system according to Example 1 of the present invention.

[0030] Figure 3 This is a power management circuit diagram in an anti-interference combustible gas alarm control system according to Example 1 of the present invention.

[0031] Figure 4 It is a scatter plot of an anti-interference combustible gas alarm control method in Example 1 of the present invention.

[0032] Among them, 1. power switch; 2. voltage regulator; 3. EMI filter. DETAILED DESCRIPTION

[0033] The present invention is further described in detail below in conjunction with the accompanying drawings.

[0034] Example 1

[0035] Reference Figure 1 , an anti-interference combustible gas alarm control system of this embodiment includes:

[0036] A data acquisition module, wherein the data acquisition module comprises a combustible gas detector and a signal collector, and the combustible gas detector is connected to the signal collector;

[0037] A data processing module, wherein the data processing module includes a single-chip microcomputer and a wireless adapter, wherein the single-chip microcomputer is connected to the wireless adapter, and the wireless adapter uploads the processing data of the single-chip microcomputer to the host computer;

[0038] An interference analysis module, wherein the interference analysis module comprises an anti-interference circuit, wherein the anti-interference circuit is connected to the single-chip microcomputer, and the anti-interference circuit performs anti-interference processing on the analog signal transmitted by the signal collector;

[0039] A power supply module, wherein the power supply module comprises a main power supply, a backup power supply and a power supply management circuit, wherein the power supply management circuit is connected to the main power supply and the backup power supply respectively.

[0040] The combustible gas detector comprises a gas sensor, a thermal resistor heater and an activated carbon filter membrane. The activated carbon filter membrane is sealed and connected to the bottom of the thermal resistor heater, and the gas sensor is nested in the periphery of the thermal resistor heater.

[0041] The single chip microcomputer is connected to the wireless adapter, comprising the step of connecting a signal output end of the single chip microcomputer to a signal input end of the wireless adapter using an SPL communication interface.

[0042] The anti-interference circuit includes a signal filtering circuit, a power filtering circuit, a power switch and a power chip. The signal output end of the signal filtering circuit is connected to the signal input end of the single-chip microcomputer. The power chip is connected to the power filtering circuit through the power switch. The output end of the power filtering circuit is connected to the voltage input end of the single-chip microcomputer.

[0043] The output end of the power filter circuit is connected to the voltage input end of the single-chip microcomputer, including the power chip connected to the gate of the power switch, the output end of the power filter circuit is connected to the source of the power switch, and the drain of the power switch is connected to the voltage input end of the single-chip microcomputer.

[0044] The signal filtering circuit comprises a differential amplifier, a digital filter and a signal processing chip. The signal processing chip is connected to a signal collector for receiving concentration information detected by a gas sensor. The differential amplifier is respectively connected to the digital filter and the signal processing chip.

[0045] The power supply filter circuit includes a first voltage stabilizing capacitor, a second voltage stabilizing capacitor, an EMI filter and a voltage stabilizer, wherein the input end of the voltage stabilizer is connected to the voltage output end of the power management circuit, the output end of the voltage stabilizer is connected to the EMI filter, and the first voltage stabilizing capacitor is connected in parallel with the second voltage stabilizing capacitor and then connected in series with the output end of the voltage stabilizer.

[0046] Specifically,

[0047] An anti-interference combustible gas alarm control system of this embodiment includes the following contents:

[0048] like Figure 1 As shown, the power filter circuit is connected to the input end of the power chip to filter out high-frequency noise and interference signals from the power management circuit. In addition, the output end of the power filter circuit is connected to the source of the power switch 1 through a diode. The output end of the power filter circuit is connected to the voltage input end of the single-chip microcomputer. The drain of the power switch 1 is connected to the voltage input end of the single-chip microcomputer. The single-chip microcomputer provides power supply for the entire control system. The power chip is connected to the gate of the power switch 1. The output power of the power switch 1 is controlled by inputting the gate voltage. When the output power of the circuit increases, the load current will also increase, which will cause the fluctuation of the power line to change. Through continuous power adjustment, the power value with the interference coefficient closest to 1 is found, which is expressed as the output power with the least interference of the power line to the signal line.

[0049] The single-chip microcomputer adopts the STC89C58 single-chip microcomputer. The signal input terminal (GPIO) of the single-chip microcomputer is connected to the signal filtering circuit to separate the power line from the signal line and thus reduce the influence of electromagnetic interference. The connecting wire of the power chip and the ground pin of the single-chip microcomputer form a loop. By connecting the ground pin, the current can flow smoothly from the single-chip microcomputer to the power chip, thereby providing the required power supply. The above connection method effectively reduces the noise and interference in the circuit and provides a stable power supply and signal environment.

[0050] like Figure 2As shown, the input end of the voltage regulator 2 is connected to the voltage output end of the power management circuit, the output end of the voltage regulator is connected to the EMI filter 3, the first voltage stabilizing capacitor is connected in parallel with the second voltage stabilizing capacitor and then connected in series with the output end of the voltage regulator, the first voltage stabilizing capacitor C1 and the second voltage stabilizing capacitor C2 are connected in parallel at both ends of the EMI filter 3 to prevent differential mode interference, and the first voltage stabilizing capacitor and the second voltage stabilizing capacitor are mainly Y capacitors to prevent common mode interference. When the common mode interference is large, its value can be increased to suppress it. For the convenience of description, the line between the voltage regulator 2 and the EMI filter 3 is called the first half of the circuit, and the EMI filter 3 and the output end line are called the second half of the circuit. The ground connection mode of the first half of the circuit is to connect the buffer resistor in parallel and then connect the ground wire through a connector. By connecting the ground wire to the shielding layer of the power filter circuit, the external electromagnetic interference and noise are guided to the ground wire, thereby reducing the impact on the circuit. In addition, the resistance of the ground wire will affect the performance of the filter circuit. In the second half of the circuit, the capacitor is connected to reduce the resistance of the ground wire, providing a lower impedance return path, so that the high-frequency noise in the power supply can flow back to the ground more effectively, thereby improving the filtering effect.

[0051] like Figure 3 As shown, the power management circuit is mainly used for switching between the backup power supply and the external power supply. The gas alarm controller adopts dual power supply mode. When there is no external power supply, the backup power supply is used for power supply. When the external power supply is connected, the main power supply is used to power the controller. The input voltage of the power management circuit is connected to the backup power supply through a P-type MOS tube, and is connected to the output end with a diode. When the main power supply is normally supplied, the backup power supply current cannot pass through the P-type MOS tube. When the main power supply loses its power supply capacity, the backup power supply starts to supply power. The above measures are used to achieve power switching.

[0052] Example 2

[0053] The difference between this embodiment and embodiment 1 is that this embodiment provides an anti-interference combustible gas alarm control method, including: placing the control system in a shielding box with a certain concentration of combustible gas, and obtaining concentration information detected by the combustible gas detector;

[0054] The concentration information detected by the combustible gas detector is used as the characteristic variable, and the concentration information received by the single-chip microcomputer is used as the result variable to calculate the interference coefficient;

[0055] The output power of the power switch is adjusted according to the interference coefficient to control the concentration error to be less than the set threshold.

[0056] The calculation of the interference coefficient includes constructing a scatter plot with the characteristic variable as the X-axis and the result variable as the Y-axis, using the scatter plot to screen data to remove data with large deviations, and calculating the interference coefficient based on the screened data. The formula for calculating the interference coefficient is:

[0057] ,

[0058] Among them, R represents the interference coefficient, i represents the i-th data sample, x represents the feature variable, y represents the result variable, and n represents the number of samples.

[0059] The method of adjusting the output power of the power switch according to the interference coefficient includes taking the minimum gate voltage when the power switch is turned on and the gate voltage when the power switch is conductively saturated as a value range, stepping in a range of 0.1V to 0.3V, and determining the output power of the power switch when the interference coefficient is closest to 1.

[0060] Specifically,

[0061] An anti-interference combustible gas alarm control method of this embodiment includes the following contents:

[0062] First, a certain concentration of combustible gas is filled into the shielding box, and the combustible gas detector is placed in the shielding box to avoid interference of the external magnetic field on the control system, and the concentration information detected by the combustible gas detector is obtained; the concentration information detected by the combustible gas detector is used as the characteristic variable, and the analog signal is transmitted through the signal collector, and the concentration information received by the microcontroller is used as the result variable, such as Figure 4 As shown, a scatter plot is constructed by using the concentration data collected multiple times to remove accidental data with large deviations. The result variable is directly affected by the characteristic variable, and the result variable and the characteristic variable are linearly correlated. The scatter plot is an integration of multiple experimental data to avoid increasing the probability of accidental occurrence due to too little sample data. The interference coefficient is only used to judge the correlation between the characteristic variable and the result variable. When the interference coefficient is close to 1, it means that the concentration information detected by the combustible gas detector is approximately equal to the concentration information received by the single-chip microcomputer, which means that the power supply noise and electromagnetic field generated by the power cord inside the system itself can interfere with the analog signal negligible.

[0063] Since the result variable and the characteristic variable are linearly correlated, this embodiment adopts a linear correlation coefficient calculation model, and the formula for calculating the interference coefficient is:

[0064] ,

[0065] Among them, R represents the interference coefficient, i represents the i-th data sample, x represents the characteristic variable, y represents the result variable, and n represents the number of samples. From the above formula, it can be seen that r is symmetrical. That is, the correlation coefficient between x and y is equal to the correlation coefficient between y and x. Whether the concentration information detected by the combustible gas detector is used as the characteristic variable or the concentration information received by the single-chip microcomputer is used as the characteristic variable, it has no effect on the calculation of the interference coefficient.

[0066] According to the power chip connected to the gate of the power switch, the output end of the power filter circuit is connected to the source of the power switch, and the drain of the power switch is connected to the voltage input end of the single-chip computer. Under the condition of meeting the minimum input power requirement of the control system, the power chip adjusts the output power of the power switch according to the size of the interference coefficient, including taking the minimum gate voltage when the power switch is turned on and the gate voltage when the power switch is conductively saturated as the value range, stepping in the range of 0.1V to 0.3V, to determine the output power with the best filtering effect, that is, the output power of the power switch when the interference coefficient is closest to 1.

[0067] The above are all preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An anti-interference combustible gas alarm control method, characterized in that: Based on an anti-interference combustible gas alarm control system, the anti-interference combustible gas alarm control system includes: A data acquisition module, wherein the data acquisition module comprises a combustible gas detector and a signal collector, and the combustible gas detector is connected to the signal collector; A data processing module, wherein the data processing module includes a single-chip microcomputer and a wireless adapter, wherein the single-chip microcomputer is connected to the wireless adapter, and the wireless adapter uploads the processing data of the single-chip microcomputer to the host computer; An interference analysis module, wherein the interference analysis module comprises an anti-interference circuit, wherein the anti-interference circuit is connected to the single-chip microcomputer, and the anti-interference circuit performs anti-interference processing on the analog signal transmitted by the signal collector; A power supply module, the power supply module comprising a main power supply, a backup power supply and a power management circuit, the power management circuit being connected to the main power supply and the backup power supply respectively; The combustible gas detector comprises a gas sensor, a thermal resistor heater and an activated carbon filter membrane, wherein the activated carbon filter membrane is sealed and connected to the bottom of the thermal resistor heater, and the gas sensor is nested in the periphery of the thermal resistor heater; The single-chip microcomputer is connected to the wireless adapter, comprising the single-chip microcomputer using an SPL communication interface to connect a signal output end of the single-chip microcomputer to a signal input end of the wireless adapter; The anti-interference circuit includes a signal filter circuit, a power filter circuit, a power switch and a power chip, the signal output end of the signal filter circuit is connected to the signal input end of the single-chip computer, the power chip is connected to the power filter circuit through the power switch, and the output end of the power filter circuit is connected to the voltage input end of the single-chip computer; The output end of the power filter circuit is connected to the voltage input end of the single-chip microcomputer, including the power chip connected to the gate of the power switch, the output end of the power filter circuit is connected to the source of the power switch, and the drain of the power switch is connected to the voltage input end of the single-chip microcomputer; The signal filtering circuit includes a differential amplifier, a digital filter and a signal processing chip, the signal processing chip is connected to a signal collector for receiving concentration information detected by a gas sensor, and the differential amplifier is respectively connected to the digital filter and the signal processing chip; The power supply filter circuit comprises a first voltage stabilizing capacitor, a second voltage stabilizing capacitor, an EMI filter and a voltage stabilizer, wherein the input end of the voltage stabilizer is connected to the voltage output end of the power management circuit, the output end of the voltage stabilizer is connected to the EMI filter, and the first voltage stabilizing capacitor is connected in parallel with the second voltage stabilizing capacitor and then connected in series with the output end of the voltage stabilizer; The anti-interference combustible gas alarm control method comprises the following steps: Place the control system in a shielded box with a certain concentration of combustible gas to obtain the concentration information detected by the combustible gas detector; The concentration information detected by the combustible gas detector is used as the characteristic variable, and the concentration information received by the single-chip microcomputer is used as the result variable to calculate the interference coefficient; The output power of the power switch is adjusted according to the interference coefficient to control the concentration error to be less than a preset threshold; The interference coefficient is calculated, including constructing a scatter plot with the characteristic variable as the X-axis and the result variable as the Y-axis, using the scatter plot to screen data to remove data with large deviations, and calculating the interference coefficient based on the screened data. The result variable and the characteristic variable are linearly correlated. The formula for calculating the interference coefficient is: , Among them, R represents the interference coefficient, i represents the i-th data sample, x represents the characteristic variable, y represents the result variable, and n represents the number of samples; The method of adjusting the output power of the power switch according to the interference coefficient includes taking the minimum gate voltage when the power switch is turned on and the gate voltage when the power switch is conductively saturated as a value range, stepping in a range of 0.1V to 0.3V, and determining the output power of the power switch when the interference coefficient is closest to 1.

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