A multi-functional gas sensor intelligent detection and calibration device for coal mines

Abstract

The present application belongs to the technical field of sensor calibration, and particularly relates to a multifunctional gas sensor intelligent detection calibration device for coal mines, which comprises a calibration table and an industrial computer host; the calibration table comprises a gas path system, a sensor control module and a main control module; the gas path system comprises a plurality of standard gas interfaces, a zero gas source, a plurality of air inlet control valves, a combiner, a flow divider, a plurality of flow regulating components, a plurality of sensor mounting interfaces and an air extraction unit; the main control module is used for communicating with the industrial computer host and receiving a calibration instruction, and controls the working states of each air inlet control valve, the zero gas source, the air extraction unit, each flow regulating component and the sensor control module according to the calibration instruction; the industrial computer host is used for configuring calibration information and generating a calibration instruction to be sent to the main control module. The present application supports high-throughput parallel calibration, has adjustable power supply and cable simulation capabilities, realizes automatic guidance and compliance control of the calibration process, and has a compact structure.

Description

Technical Field

[0001] This invention belongs to the field of sensor calibration technology, and in particular relates to an intelligent detection and calibration device for a multifunctional gas sensor used in coal mines. Background Technology

[0002] In the coal mine safety production system, gas sensors are core equipment for monitoring the concentrations of critical gases such as methane (CH4), carbon monoxide (CO), and oxygen (O2). Their measurement accuracy and reliability are directly related to the safety of miners and the effectiveness of disaster early warning. According to relevant standards, all gas sensors in use must be calibrated regularly to correct problems such as zero-point drift and sensitivity decay caused by long-term operation, ensuring their continuous and stable operation.

[0003] To improve calibration efficiency and standardization, multifunctional gas sensor calibration devices have emerged. However, currently widely used mature calibration equipment still suffers from numerous technical bottlenecks, severely hindering the improvement of intelligent operation and maintenance levels in coal mines.

[0004] First, in terms of calibration efficiency, existing devices typically only support the simultaneous calibration of up to five sensors. However, in large coal mines, a single annual inspection or periodic maintenance often involves dozens or even hundreds of sensors. Frequent replacements and batch-by-batch calibrations are not only time-consuming and labor-intensive, but also prone to errors introduced by human operation, making it difficult to meet the needs of efficient and large-scale modern safety management.

[0005] Secondly, regarding power supply compatibility, different models and manufacturers of gas sensors have varying operating voltage requirements (such as 5V, 9V, 12V, 18V, etc.). Traditional calibration devices mostly use fixed voltage outputs, which cannot flexibly match the power supply requirements of various sensors, causing some sensors to fail to start normally or malfunction, thus limiting the versatility and applicability of the device.

[0006] Secondly, regarding calibration process control, existing equipment generally relies on manual adjustment of gas flow, switching of gas paths, and determination of purging time. The operation steps are cumbersome and highly dependent on the operator's experience. If the process is not executed properly (such as insufficient purging or insufficient standard gas introduction time), it will directly lead to inaccurate calibration results, and even the risk of "false pass". In addition, most calibration devices highly integrate the gas path system, control unit and host computer into an integrated chassis, making the whole machine bulky and heavy, making on-site installation, disassembly and transportation extremely inconvenient, especially unfavorable for working in confined downhole spaces and rapid deployment for annual mandatory verification.

[0007] Therefore, how to provide a smart detection and calibration device for multifunctional gas sensors used in coal mines that supports high-throughput parallel calibration, has adjustable power supply and cable simulation capabilities, realizes automatic guidance and compliance management of the calibration process, and has a compact structure that is easy to deploy on site has become an urgent problem to be solved. Summary of the Invention

[0008] To address the shortcomings of the existing technologies, this invention provides a multifunctional gas sensor intelligent detection and calibration device for coal mines, which supports high-throughput parallel calibration, has adjustable power supply and cable simulation capabilities, realizes automatic guidance and compliance management of the calibration process, and has a compact structure for easy on-site deployment.

[0009] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0010] A multifunctional gas sensor intelligent detection and calibration device for coal mines includes a calibration platform and an industrial control host computer;

[0011] The calibration station includes a pneumatic system, a sensor control module, and a main control module;

[0012] The gas path system includes multiple standard gas interfaces, a zero gas source, multiple intake control valves, a combiner, a splitter, multiple flow regulating components, multiple sensor mounting interfaces, and a pumping unit. Each standard gas interface is connected to a preset type of standard gas input device and, through a corresponding intake control valve, to the input end of the combiner. The zero gas source is also connected to the input end of the combiner through a corresponding intake control valve. The output end of the combiner is connected to the input end of the splitter. The splitter has one exhaust end and at least n output ends, each output end being connected to a corresponding sensor mounting interface through a corresponding flow regulating component. The exhaust end is connected to the pumping unit; n > 5.

[0013] The sensor control module is used to provide independent and adjustable operating voltage for the gas sensors installed at each sensor mounting interface, and is also used to simulate the load circuit of a cable of a preset length.

[0014] The main control module is used to communicate with the industrial control host computer and receive calibration instructions, and control the working status of each intake control valve, zero air source, air extraction unit, each flow regulation component and sensor control module according to the calibration instructions;

[0015] The industrial control host computer is used to configure calibration information and generate calibration instructions to send to the main control module; the main control module is used to receive the calibration instructions, execute the corresponding calibration operations, and send the calibration data back to the industrial control host computer to generate a calibration report.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. By setting up a flow divider and configuring n (n>5) independent sensor mounting interfaces, along with multi-channel flow regulation components and independently controlled gas path channels, the device can simultaneously perform parallel calibration of multiple gas sensors. Compared to traditional equipment that typically only supports serial or semi-parallel operation of up to 5 sensors, this solution significantly reduces the time required for batch calibration, effectively meeting the needs of large-scale periodic sensor verification in coal mines.

[0018] 2. Enhanced equipment versatility and adaptability. The sensor control module can provide an independent and adjustable operating voltage for each mounting interface and can simulate the load effect caused by cables of different lengths. This design overcomes the limitation of existing calibration devices that cannot be compatible with various sensor models due to fixed power supply, allowing the same device to be flexibly adapted to gas sensors of different manufacturers and specifications, thus improving the applicability and value of the device.

[0019] 3. Automating and intelligently managing the calibration process. The industrial control host computer and the main control module work together to automatically generate calibration instructions based on preset calibration information. The main control module precisely controls the timing of the intake valve, zero air source, extraction unit, and flow regulation components, replacing the cumbersome traditional operations that rely on manual intervention. Simultaneously, the system dynamically prompts key operational steps (such as air exchange and purging), and records and marks non-standard operations, ensuring a standardized and traceable calibration process and significantly reducing the risk of human error.

[0020] 4. The device adopts a separate design for the calibration platform and the industrial control host computer. The complex pneumatic circuit and control hardware are integrated into the calibration platform, while the human-machine interaction and data processing functions are handled by a separate host computer. Compared with the highly integrated and bulky calibration equipment in the existing technology, this architecture not only reduces the space occupied in the underground operation, but also facilitates transportation, installation and annual inspection and maintenance, and better meets the needs of coal mine sites for equipment portability and modularity.

[0021] In summary, this invention supports high-throughput parallel calibration, has adjustable power supply and cable simulation capabilities, enables automatic guidance and compliance management of the calibration process, and has a compact structure that facilitates on-site deployment.

[0022] Preferably, the industrial control host computer is used to configure a test process for the gas sensor to be calibrated, which includes at least one test task. The test task includes basic calibration, alarm error test, repeatability test, response time test and drift test. The host computer associates each test task with a corresponding standard gas interface or zero gas source to generate a calibration instruction containing the test task, task sequence and corresponding gas source information, and sends the calibration instruction to the main control module.

[0023] After receiving the calibration command, the main control module controls the opening and closing of the intake control valve corresponding to the standard gas interface or zero gas source associated with each test task in the order of the test tasks, so as to perform zeroing, gas introduction, sensor output signal acquisition and exhaust operations.

[0024] This setup allows the industrial control host computer to support various testing tasks, including basic calibration, alarm error testing, repeatability testing, response time testing, and drift testing, covering key dimensions of gas sensor performance evaluation. Compared to traditional calibration devices that only perform simple zero-point and range calibration, this solution systematically expands the scope of calibration, enabling the calibration results to more accurately reflect the sensor's comprehensive performance under actual operating conditions and improving detection reliability.

[0025] 2. Users can freely combine test tasks, adjust the task order, and specify corresponding gas sources according to the type of sensor being tested or the usage scenario, forming a personalized test process. This flexible configuration capability is significantly superior to the fixed and single calibration program in existing equipment, and can adapt to the differentiated testing needs of various gas sensors (such as CH4, CO, O2, etc.) in coal mines, improving the applicability and intelligence level of the device.

[0026] Preferably, the calibration station further includes an acoustic-optical testing unit, which includes a sound level meter; the main control module is also used to control the gas path system to introduce a preset high concentration of standard gas into the gas sensor to be calibrated when the calibration command issued by the industrial control host computer includes an alarm error test, and to collect the alarm sound intensity signal emitted by the gas sensor to be calibrated through the sound level meter to determine whether the alarm sound intensity signal meets the preset sound level threshold.

[0027] Preferably, the sensor control module includes a load circuit and a power supply control unit; the load circuit is used to simulate the line impedance of a cable of a preset length downhole so that the sensor is in electrical conditions consistent with its actual downhole power supply conditions during the calibration process; the power supply control unit is used to provide independent and adjustable operating voltage for the gas sensors installed at each sensor mounting interface.

[0028] This configuration allows the load circuit to simulate the line impedance introduced by a pre-set length of cable in actual downhole use, ensuring that the sensor experiences the same voltage drop and load characteristics during calibration as in the field. Compared to traditional calibration devices that directly provide ideal power without considering line losses, this solution effectively avoids the problem of "calibration qualified, field inaccurate" caused by differences in power supply conditions, significantly improving the engineering reliability of the calibration results.

[0029] Preferably, the calibration station also includes an environmental monitoring unit; the environmental monitoring unit includes a temperature and humidity sensor and an atmospheric pressure sensor, and the signal output terminals of the temperature and humidity sensor and the atmospheric pressure sensor are both connected to the main control module to provide the main control module with environmental temperature, humidity and atmospheric pressure parameters during the calibration process.

[0030] Preferably, the calibration station is also equipped with a reserved RS485 communication interface for connecting an external calibrated reference gas sensor; the main control module is used to obtain the ambient gas concentration signal output by the reference gas sensor through the reserved RS485 communication interface before or after the zeroing operation, and when the ambient gas concentration signal is higher than the preset residual threshold, the control source corresponding to the air intake control valve is opened and the pumping unit is started to purge until the ambient gas concentration signal meets the zeroing condition.

[0031] This setup, before or after zero-point calibration (zeroing), uses a calibrated reference gas sensor to monitor the residual concentration of the target gas in the calibration chamber in real time, avoiding "false zero points" caused by the presence of incompletely purged standard gas or environmental interference gases in the chamber. Compared to traditional calibration devices that rely solely on fixed-time purging or manual judgment, this solution uses real concentration data as a prerequisite for zeroing, fundamentally ensuring the accuracy of zero-point calibration.

[0032] Preferably, the combiner is a multi-inlet, single-outlet gas path connector used to combine multiple gas inlets into a single outlet; the splitter is a single-inlet, multi-outlet gas path distribution connector used to distribute input gas to multiple output channels.

[0033] Preferably, the industrial control host computer is also equipped with a digital twin modeling module, which is used to create and maintain a digital twin for each gas sensor to be calibrated with a unique identifier; the digital twin shall continuously record at least the following data for each calibration of the sensor: calibration time point, ambient temperature and humidity, calibration gas concentration, sensor zero point reading, sensor range reading, response time, and alarm error test results.

[0034] Preferably, the industrial control host computer is also equipped with a performance prediction module. The performance prediction module is used to predict the zero drift or sensitivity decay trend of the sensor in the next calibration cycle based on the historical calibration data in the digital twin of each sensor. The industrial control host computer generates a compensation parameter according to the prediction result. The compensation parameter is used to adjust the calibration reference of the sensor during the current calibration process so as to minimize the cumulative measurement error of the sensor in the next calibration cycle after calibration. When the main control module performs the current calibration operation, it adjusts the mapping relationship between the sensor output signal and the theoretical concentration value collected during the standard gas introduction stage according to the compensation parameter, generates optimized calibration coefficients, and writes the calibration coefficients into the sensor or records them in the calibration report.

[0035] This setup, 1) relies on the digital twin modeling module to continuously accumulate multi-dimensional data (including zero point, range, response time, environmental parameters, etc.) from each calibration cycle for each sensor with a unique identifier, forming a dedicated "health record." Based on this historical data, the performance prediction module can accurately predict its zero-point drift trend or sensitivity decay pattern in the next calibration cycle, enabling calibration decisions to shift from passive response to proactive prediction.

[0036] 2. Optimizing full-cycle measurement accuracy through preset initial deviation. Unlike traditional calibration that aims for "perfect consistency between the current reading and the standard value," this approach consciously introduces a reverse-compensating initial deviation during the calibration process (e.g., calibrating a 1.0% standard gas as a 0.95% output reference). This deviation aims to offset the predictable positive drift of the sensor in subsequent use, ensuring that its actual output trajectory is "centered" near the true concentration throughout the calibration cycle. For example, under traditional calibration, the sensor might drift from 1.0% to 1.1%, with an error of +0.1%; however, using this method, its output gradually drifts from 0.95% to 1.05%, compressing the overall error range from ±0.10% to ±0.05%, significantly improving the accuracy stability throughout the entire cycle.

[0037] 3. Generate personalized and traceable optimized calibration coefficients. Based on the compensation parameters, the main control module dynamically adjusts the mapping relationship between the sensor output signal and the theoretical concentration during the standard gas introduction stage, generating optimized calibration coefficients and writing them into the sensor or including them in the calibration report. This not only ensures the scientific validity of the calibration results but also provides reliable data support for subsequent performance tracking and lifespan management. Attached Figure Description

[0038] To make the objectives, technical solutions, and advantages of the invention clearer, the invention will now be described in further detail with reference to the accompanying drawings, wherein:

[0039] Figure 1 This is a schematic diagram of the intelligent detection and calibration device for a multifunctional gas sensor used in coal mines in Example 1;

[0040] Figure 2 This is a hardware system block diagram of the intelligent detection and calibration device for a multifunctional gas sensor used in coal mines in Example 1;

[0041] Figure 3 This is a schematic diagram of the gas path system in Example 1. Detailed Implementation

[0042] The following detailed explanation illustrates the specific implementation methods:

[0043] Example 1

[0044] like Figure 1 , Figure 2 As shown in the figure, this embodiment discloses an intelligent detection and calibration device for a multifunctional gas sensor used in coal mines, including a calibration platform and an industrial control host computer.

[0045] The calibration station includes a pneumatic system, a sensor control module, and a main control module.

[0046] like Figure 3 As shown, the gas path system includes multiple standard gas interfaces, a zero gas source, multiple intake control valves, a combiner, a splitter, multiple flow regulating components, multiple sensor mounting interfaces, and a pumping unit. Each standard gas interface is connected to a preset type of standard gas input device and is connected to the input end of the combiner via a corresponding intake control valve. The zero gas source is also connected to the input end of the combiner via a corresponding intake control valve. The output end of the combiner is connected to the input end of the splitter. The splitter has one exhaust end and at least n output ends, each output end being connected to a corresponding sensor mounting interface via a corresponding flow regulating component. The exhaust end is connected to the pumping unit; n > 5. For illustrative purposes, n is 10 in this embodiment. In specific implementation, the combiner is a multi-inlet, one-outlet gas path connector used to merge multiple intake gas streams into a single outlet; the splitter is a one-inlet, multi-outlet gas path distribution connector used to distribute the input gas to multiple output channels.

[0047] The sensor control module provides independent and adjustable operating voltages for the gas sensors installed at each sensor mounting interface and also simulates the load circuit of a cable of a preset length. In practice, the sensor control module includes a load circuit and a power supply control unit. The load circuit simulates the line impedance of the preset length cable in the well, ensuring that the sensor operates under electrical conditions consistent with its actual power supply in the well during calibration. The power supply control unit provides independent and adjustable operating voltages for the gas sensors installed at each sensor mounting interface. In this way, the load circuit can simulate the line impedance introduced by the preset length cable in actual well operation, allowing the sensor to withstand the same voltage drop and load characteristics as in the field during calibration. Compared to traditional calibration devices that directly provide ideal power without considering line losses, this solution effectively avoids the problem of "calibration qualified, field inaccurate" caused by differences in power supply conditions, significantly improving the engineering reliability of the calibration results.

[0048] The main control module is used to communicate with the industrial control host computer and receive calibration instructions, and control the working status of each intake control valve, zero air source, air extraction unit, each flow regulation component and sensor control module according to the calibration instructions;

[0049] The industrial control host computer is used to configure calibration information and generate calibration instructions to send to the main control module; the main control module is used to receive the calibration instructions, execute the corresponding calibration operations, and send the calibration data back to the industrial control host computer to generate a calibration report.

[0050] In practice, the industrial control host computer configures a test process for the gas sensor to be calibrated, which includes at least one test task. The test tasks include basic calibration, alarm error test, repeatability test, response time test, and drift test. Each test task is associated with a corresponding standard gas interface or zero gas source to generate a calibration instruction containing the test task, task sequence, and corresponding gas source information. The calibration instruction is then sent to the main control module. After receiving the calibration instruction, the main control module controls the opening and closing of the intake control valve corresponding to the standard gas interface or zero gas source associated with each test task in sequence, according to the order of the test tasks, to perform zeroing, gas introduction, sensor output signal acquisition, and exhaust operations.

[0051] In this way, the industrial control host computer supports configuration of various test tasks, including basic calibration, alarm error testing, repeatability testing, response time testing, and drift testing, covering the key dimensions of gas sensor performance evaluation. Compared with traditional calibration devices that only perform simple zero-point and range calibration, this solution systematically expands the calibration scope, enabling the calibration results to more accurately reflect the sensor's comprehensive performance under actual working conditions and improving detection reliability. Users can freely combine test tasks, adjust the task order, and specify corresponding gas sources according to the type of sensor being tested or the usage scenario, forming a personalized test process. This flexible configuration capability is significantly superior to the fixed and single calibration program in existing equipment, and can adapt to the differentiated testing needs of various gas sensors (such as CH4, CO, O2, etc.) in coal mines, improving the applicability and intelligence level of the device.

[0052] It should be noted that, in practice, after configuring the test procedure for the gas sensor to be calibrated, it can be saved directly as a template. In this way, when using the corresponding gas, the configuration information can be directly called and a simple modification can be made.

[0053] In practice, the calibration station also includes an acoustic-optical testing unit, which includes a sound level meter. The main control module is also used to control the gas path system to introduce a preset high-concentration standard gas into the gas sensor to be calibrated when the calibration command issued by the industrial control host computer includes an alarm error test. The system then collects the alarm sound intensity signal emitted by the gas sensor through the sound level meter to determine whether the alarm sound intensity signal meets the preset sound level threshold. For example, during the calibration of a methane sensor, when 1.5% CH4 standard gas is introduced, the sensor should trigger an acoustic-optical alarm. At this time, the MCU (i.e., the main control module) automatically activates the acoustic-optical alarm component and synchronously reads the sound level count value. If the sound intensity is below 75dB, the sensor's alarm function is deemed unqualified.

[0054] The calibration station also includes an environmental monitoring unit; the environmental monitoring unit includes a temperature and humidity sensor and an atmospheric pressure sensor. The signal output terminals of the temperature and humidity sensor and the atmospheric pressure sensor are connected to the main control module to provide the main control module with the environmental temperature, humidity and atmospheric pressure parameters during the calibration process.

[0055] The calibration station also features a reserved RS485 communication interface for connecting an external calibrated reference gas sensor. The main control module acquires the ambient gas concentration signal output by the reference gas sensor via this interface before or after the zeroing operation. When the ambient gas concentration signal exceeds a preset residual threshold, the control valve corresponding to the control source opens, and the purging unit is activated to purge until the ambient gas concentration signal meets the zeroing conditions. This allows for real-time monitoring of the residual concentration of the target gas within the calibration chamber before or after zeroing, preventing "false zeros" caused by incomplete purging of standard gas or interfering ambient gases. Compared to traditional calibration devices that rely solely on fixed-time purging or manual judgment, this solution uses real concentration data as a prerequisite for zeroing, fundamentally ensuring the accuracy of zeroing.

[0056] In specific implementation, the industrial control host computer is also used to dynamically display operation guidance information to the operator during the calibration process according to the calibration execution sequence defined by the calibration instruction. The operation guidance information includes standard gas replacement prompts and purging waiting time estimates. When it is detected that the operator skips the key steps indicated by the operation guidance information, the industrial control host computer records a non-standard operation log and marks the corresponding calibration result as a non-standard process in the calibration report.

[0057] This invention, by setting up a flow divider and configuring n (n>5) independent sensor mounting interfaces, along with multi-channel flow regulation components and independently controlled gas path channels, enables the device to simultaneously calibrate multiple gas sensors in parallel. Compared to traditional equipment that typically only supports serial or semi-parallel operation of up to 5 sensors, this solution significantly reduces the time required for batch calibration, effectively addressing the need for periodic verification of large-scale sensors in coal mines. Furthermore, the sensor control module can provide an independent and adjustable operating voltage for each mounting interface and can simulate the load effect caused by cables of different lengths. This design overcomes the limitation of existing calibration devices that cannot be compatible with various sensor models due to fixed power supply, allowing the same device to flexibly adapt to gas sensors of different manufacturers and specifications, thus improving the applicability and value of the device. Moreover, the industrial control host computer works collaboratively with the main control module, automatically generating calibration instructions based on preset calibration information. The main control module precisely controls the timing of the inlet valve, zero gas source, extraction unit, and flow regulation components, replacing the cumbersome traditional operation that relies on manual intervention. Meanwhile, the system can dynamically prompt key operation steps (such as ventilation, purging, etc.) and record and mark non-standard operations to ensure that the calibration process is standardized and traceable, significantly reducing the risk of human error.

[0058] This invention supports high-throughput parallel calibration, has adjustable power supply and cable simulation capabilities, realizes automatic guidance and compliance management of the calibration process, and has a compact structure that is easy to deploy on site.

[0059] Example 2

[0060] Unlike Embodiment 1, in this embodiment, the industrial control host computer is also equipped with a digital twin modeling module, which is used to create and maintain a digital twin for each gas sensor to be calibrated with a unique identifier; the digital twin continuously records at least the following data for each calibration of the sensor: calibration time point, ambient temperature and humidity, calibration gas concentration, sensor zero point reading, sensor range reading, response time, and alarm error test results.

[0061] The industrial control host computer is also equipped with a performance prediction module. This module is used to predict the zero-point drift or sensitivity decay trend of each sensor in the next calibration cycle based on historical calibration data in the digital twin of each sensor. The industrial control host computer generates a compensation parameter based on the prediction result. This compensation parameter is used to adjust the calibration reference of the sensor during the current calibration process so as to minimize the cumulative measurement error of the sensor in the next calibration cycle after calibration. When the main control module performs the calibration operation, it adjusts the mapping relationship between the sensor output signal and the theoretical concentration value collected during the standard gas introduction stage according to the compensation parameter, generates optimized calibration coefficients, and writes the calibration coefficients into the sensor or records them in the calibration report.

[0062] In practice, the performance prediction module can predict the zero-point drift or sensitivity decay trend of the sensor in the next calibration cycle using a pre-configured prediction model (such as a time series prediction model). Existing models can be used for prediction, and will not be elaborated further here.

[0063] In this way, relying on the digital twin modeling module, multi-dimensional data (including zero point, range, response time, environmental parameters, etc.) from each calibration cycle are continuously accumulated for each sensor with a unique identifier, forming a unique "health record". Based on this historical data, the performance prediction module can accurately predict its zero-point drift trend or sensitivity decay pattern in the next calibration cycle, shifting calibration decisions from passive response to proactive prediction. In addition, unlike traditional calibration that strives for "perfect consistency between the current reading and the standard value", this solution consciously introduces an initial bias with reverse compensation in this calibration (for example, calibrating a 1.0% standard gas as a 0.95% output reference). This bias aims to offset the predictable positive drift of the sensor in subsequent use, ensuring that its actual output trajectory throughout the entire calibration cycle is "centered" near the true concentration. For example, under traditional calibration, the sensor might drift from 1.0% to 1.1%, with an error of +0.1%. However, using this method, its output gradually drifts from 0.95% to 1.05%, and the overall error range is compressed from ±0.10% to ±0.05%, significantly improving the accuracy and stability throughout the entire cycle. Furthermore, based on compensation parameters, the main control module dynamically adjusts the mapping relationship between the sensor output signal and the theoretical concentration during the standard gas introduction phase, generating optimized calibration coefficients, which are then written into the sensor or included in the calibration report. This not only ensures the scientific validity of the calibration results but also provides reliable data support for subsequent performance tracking and lifespan management.

[0064] This invention breaks through the limitations of traditional calibration which only focuses on "current matching". Through a predictive compensation strategy driven by digital twins, it realizes the active control of the measurement performance of the sensor throughout its entire life cycle, which significantly improves the reliability and safety of the coal mine gas monitoring system in long-term operation.

[0065] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit the technical solutions. Those skilled in the art should understand that any modifications or equivalent substitutions to the technical solutions of the present invention without departing from the spirit and scope of the present invention should be covered within the scope of the claims of the present invention.

Claims

1. A multifunctional gas sensor intelligent detection and calibration device for coal mines, characterized in that: Including calibration platform and industrial control host computer; The calibration station includes a pneumatic system, a sensor control module, and a main control module; The gas path system includes multiple standard gas interfaces, a zero gas source, multiple intake control valves, a combiner, a splitter, multiple flow regulating components, multiple sensor mounting interfaces, and a pumping unit. Each standard gas interface is connected to a preset type of standard gas input device and, through a corresponding intake control valve, to the input end of the combiner. The zero gas source is also connected to the input end of the combiner through a corresponding intake control valve. The output end of the combiner is connected to the input end of the splitter. The splitter has one exhaust end and at least n output ends, each output end being connected to a corresponding sensor mounting interface through a corresponding flow regulating component. The exhaust end is connected to the pumping unit; n > 5. The sensor control module is used to provide independent and adjustable operating voltage for the gas sensors installed at each sensor mounting interface, and is also used to simulate the load circuit of a cable of a preset length. The main control module is used to communicate with the industrial control host computer and receive calibration instructions, and control the working status of each intake control valve, zero air source, air extraction unit, each flow regulation component and sensor control module according to the calibration instructions; The industrial control host computer is used to configure calibration information and generate calibration instructions to send to the main control module; the main control module is used to execute the corresponding calibration operation after receiving the calibration instructions and send the calibration data back to the industrial control host computer to generate a calibration report. The industrial control host computer is also equipped with a digital twin modeling module, which is used to create and maintain a digital twin for each gas sensor to be calibrated with a unique identifier; the digital twin shall continuously record at least the following data for each calibration of the sensor: calibration time point, ambient temperature and humidity, calibration gas concentration, sensor zero point reading, sensor range reading, response time, and alarm error test results; The industrial control host computer is also equipped with a performance prediction module. This module is used to predict the zero-point drift or sensitivity decay trend of each sensor in the next calibration cycle based on historical calibration data in the digital twin of each sensor. The industrial control host computer generates a compensation parameter based on the prediction result. This compensation parameter is used to adjust the calibration reference of the sensor during the current calibration process so as to minimize the cumulative measurement error of the sensor in the next calibration cycle after calibration. When the main control module performs the current calibration operation, it adjusts the mapping relationship between the sensor output signal and the theoretical concentration value collected during the standard gas introduction stage according to the compensation parameter, generates optimized calibration coefficients, and writes the calibration coefficients into the sensor or records them in the calibration report. The calibration station is also equipped with a reserved RS485 communication interface for connecting an external calibrated reference gas sensor. The main control module is used to obtain the ambient gas concentration signal output by the reference gas sensor through the reserved RS485 communication interface before or after the zeroing operation. When the ambient gas concentration signal is higher than the preset residual threshold, the module controls the intake control valve corresponding to the zero gas source to open and starts the pumping unit to purge until the ambient gas concentration signal meets the zeroing condition.

2. The intelligent detection and calibration device for a multifunctional gas sensor used in coal mines as described in claim 1, characterized in that: The industrial control host computer is used to configure a test process for the gas sensor to be calibrated, which includes at least one test task. The test task includes basic calibration, alarm error test, repeatability test, response time test and drift test. It also associates each test task with a corresponding standard gas interface or zero gas source to generate a calibration instruction containing the test task, task sequence and corresponding gas source information, and sends the calibration instruction to the main control module. After receiving the calibration command, the main control module controls the opening and closing of the intake control valve corresponding to the standard gas interface or zero gas source associated with each test task in the order of the test tasks, so as to perform zeroing, gas introduction, sensor output signal acquisition and exhaust operations.

3. The intelligent detection and calibration device for a multifunctional gas sensor used in coal mines as described in claim 2, characterized in that: The calibration station also includes an environmental monitoring unit; the environmental monitoring unit includes a temperature and humidity sensor and an atmospheric pressure sensor. The signal output terminals of the temperature and humidity sensor and the atmospheric pressure sensor are connected to the main control module to provide the main control module with the environmental temperature, humidity and atmospheric pressure parameters during the calibration process.

4. The intelligent detection and calibration device for a multifunctional gas sensor used in coal mines as described in claim 2, characterized in that: The calibration station also includes an acoustic and optical testing unit, which includes a sound level meter. The main control module is also used to control the gas path system to introduce a preset high concentration of standard gas into the gas sensor to be calibrated when the calibration command issued by the industrial control host computer includes an alarm error test, and to collect the alarm sound intensity signal emitted by the gas sensor to be calibrated through the sound level meter to determine whether the alarm sound intensity signal meets the preset sound level threshold.

5. The intelligent detection and calibration device for a multifunctional gas sensor used in coal mines as described in claim 1, characterized in that: The sensor control module includes a load circuit and a power supply control unit. The load circuit is used to simulate the line impedance of a cable of a preset length downhole so that the sensor is in electrical conditions consistent with its actual downhole power supply conditions during calibration. The power supply control unit is used to provide independent and adjustable operating voltages for the gas sensors installed at each sensor mounting interface.

6. The intelligent detection and calibration device for a multifunctional gas sensor used in coal mines as described in claim 1, characterized in that: The combiner is a multi-inlet, single-outlet gas path connector used to combine multiple gas inlets into a single outlet; the splitter is a single-inlet, multi-outlet gas path distribution connector used to distribute input gas to multiple output channels.

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