Indoor air quality monitoring device and sensor coordination control system

Abstract

This invention provides an indoor air quality monitoring device and sensor collaborative control system, relating to the field of indoor environmental monitoring technology. It addresses the problems of response lag, temperature drift accumulation, and decreased alarm reachability that occur during long-term operation of air monitoring devices. By treating structural influences as a first-type input and unifying their parameterization, the device achieves feedforward identification and closed-loop suppression of sample degradation, filter material contamination and misalignment, internal thermal drift, and acoustic attenuation. The sampling confirmation window is adaptively adjusted to reduce false alarms; channel-level temperature drift compensation and power derating are prioritized and executed collaboratively for steady-state temperature control; the alert link maintains subjective loudness consistency based on equivalent gain; and the baseline is refreshed after maintenance to maintain long-term consistency. Thus, without altering the mechanical form, the device significantly improves monitoring accuracy, stability, and alarm reachability, highlighting the value of structure-aware driven device-level design.

Description

Technical Field

[0001] The present invention relates to the technical field of indoor environmental monitoring, and particularly to an indoor air quality monitoring device and a sensor collaborative control system. Background Art

[0002] Existing indoor air quality monitoring mainly relies on environmental readings such as gas concentration, temperature and humidity for determination, and it is difficult to timely identify potential impacts of structural factors such as changes in the sampling path, filter material state, internal heat coupling, and acoustic opening attenuation on the measurement and prompting links, resulting in problems such as response hysteresis, temperature drift accumulation, and decreased alarm accessibility during long-term operation. The common practice in the industry is threshold alarm and regular calibration, lacking a general framework that quantifies the structural impacts into unified computable inputs and conducts online linkage control. Summary of the Invention

[0003] Aiming at the defects existing in the prior art, the present invention provides an indoor air quality monitoring device and a sensor collaborative control system.

[0004] To solve the above technical problems, an indoor air quality monitoring device and a sensor collaborative control system provided by the present invention include a base and a housing. An arc-shaped installation groove is formed at the front end of the housing. A filter screen is detachably arranged in the arc-shaped installation groove. The filter screen is provided with a first magnetic block, and the arc-shaped front edge of the housing is provided with second magnetic blocks at intervals. The first magnetic block and the second magnetic block are adsorbed and positioned relatively. A carbon dioxide sensor is arranged in a sensing cavity behind the arc-shaped installation groove. The two pressure-taking ends of a double-chamber differential pressure sensor are respectively connected to the front cavity outside the filter screen and the rear cavity inside through capillary tubes. An optical emitter and an optical receiver are coaxially arranged inside the arc-shaped installation groove to form an optical emitter-receiver device, and its optical path passes through the filter screen. A filter screen positioning angle sensor is arranged at the filter screen support near the first magnetic block. An internal temperature sensor is arranged in the sensing cavity or its metal support, and an external temperature sensor is arranged at the upstream of the air inlet of the housing or at the outside opening. A power detection module is connected in series in the heating or main energy-consuming circuit of the device. A buzzer is arranged at the rear end of the housing corresponding to a sound hole, and an acoustic sampling sensor is arranged inside the sound hole and axially aligned with the buzzer. The main board is electrically connected to the above-mentioned sensors and modules, and is configured to calculate structural parameters based on the electrical signals measured by each of them and execute a control state machine with the parameters as inputs.

[0005] Preferably, the optical beam emitter and the optical beam receiver are coaxial and their optical paths only pass through the effective area of ​​the filter screen. A light-shielding structure is provided inside the arc-shaped mounting groove to suppress stray incident light. The motherboard stores constants κ and γ related to the calibration of the filter screen's optical parameters, as well as a reference light intensity I0. κ and γ are stored in non-volatile memory, and I0 is updated after the filter screen is cleaned or replaced and is called by the motherboard as a baseline parameter for optical measurements.

[0006] Preferably, the first and second pressure-taking ends of the dual-cavity differential pressure sensor are connected to the outer front cavity and the inner rear cavity of the filter screen respectively through independent capillary tubes. The capillary tubes are wired along the inner wall of the housing and avoid the internal heat source and the optical path area of ​​the optical transmitting device. The motherboard acquires the differential pressure signal at a frequency of not less than five times per second and extracts representative values ​​of the instantaneous measurement using the sliding median or percentile. At the same time, the reference differential pressure ΔPref and the maximum allowable differential pressure ΔPmax are stored in non-volatile memory for normalization calculation.

[0007] Preferably, the carbon dioxide sensor is used to output a concentration time series. The motherboard opens an event window and performs fitting calculations when a step change in concentration is detected. The sampling frequency of the carbon dioxide sensor is not less than once per second. The motherboard calculates the equivalent injection diffusion time constant based on the data from two times t1 and t2. The time constant is calculated using the following formula: Where C∞ is the steady-state concentration, and C(t1) and C(t2) are the concentration sampling values ​​at the corresponding times. The calculation is performed within the event window to suppress outliers and update parameters.

[0008] Preferably, the internal temperature sensor and the external temperature sensor are connected to the motherboard via independent buses. The power detection module is a shunt resistor sampling circuit or a power metering chip and is electrically connected to the analog-to-digital conversion unit of the motherboard. The motherboard calculates the equivalent thermal resistance Rth based on Ts, Tenv, and the equivalent power P, which is equal to (Ts-Tenv) / P. The acoustic sampling sensor outputs the root mean square sound pressure at an internal sampling rate of not less than 8 kHz and is used together with the root mean square value of the driving voltage of the buzzer to calculate the acoustic gain. The acoustic link calibration coefficients are stored in the non-volatile memory of the motherboard.

[0009] A sensor-coordinated monitoring system for indoor air quality monitoring equipment, the system comprising an indoor air quality monitoring device, a processor, and a memory;

[0010] The indoor air quality monitoring device includes: a detachable filter screen disposed in an arc-shaped mounting groove and a first magnetic block and a second magnetic block adsorbed and positioned relative to the filter screen; a carbon dioxide sensor disposed in a sensing cavity after the arc-shaped mounting groove; a dual-cavity differential pressure sensor whose two pressure taps are respectively connected to the outer front cavity of the filter screen and the inner rear cavity of the filter screen via independent capillary tubes; an optical through-beam transmitter and an optical through-beam receiver coaxially disposed and whose optical path passes through the filter screen; a filter screen positioning angle sensor disposed near the filter screen support of the first magnetic block; an inner temperature sensor attached to the sensing cavity or its metal bracket; an outer temperature sensor disposed upstream of the air inlet or at the outer opening of the outer shell; a power detection module connected in series with the heating or main energy consumption circuit; a buzzer disposed at the rear end of the outer shell corresponding to the speaker hole; and an acoustic sampling sensor located inside the speaker hole and aligned axially with the buzzer.

[0011] The processor is electrically connected to the memory, the carbon dioxide sensor, the dual-cavity differential pressure sensor, the optical through-beam transmitter and the optical through-beam receiver, the filter positioning angle sensor, the internal temperature sensor, the external temperature sensor, the power detection module, the buzzer, and the acoustic sampling sensor.

[0012] The memory stores program instructions that run on the processor, which is configured to: acquire electrical signals from the sensors and modules and calculate a set of structural parameters, including a filter placement deviation angle, an equivalent injection diffusion time constant based on a concentration time series, a filter optical porosity based on transmitted light intensity and a calibration constant, a clogging index based on the inter-filter micro-pressure difference, a reference pressure difference, and a maximum allowable pressure difference, an equivalent thermal resistance calculated from the internal temperature, the external temperature, and the equivalent power, and an acoustic gain calculated from the acoustic sampling signal, the buzzer drive voltage, and the acoustic link calibration coefficient.

[0013] The set of structural parameters is used as input to execute a control state machine. The control state machine is configured to generate control signals based on preset thresholds and mappings for sampling confirmation time window management, channel-level temperature compensation parameter acquisition, derating and sorting control of display brightness, wireless transmission duty cycle and buzzer duty cycle, and maintenance and positioning prompt control. The control signals are then sent to the display screen, the wireless communication interface and the buzzer respectively.

[0014] Preferably, the optical through-beam transmitter and the optical through-beam receiver are coaxial and their optical paths only pass through the effective area of ​​the filter. A light-shielding structure is provided inside the arc-shaped mounting slot. The memory stores calibration constants κ and γ related to optical measurements and a reference light intensity I0. The processor is configured to calculate the optical porosity of the filter according to the mapping relationship between I and I0 and to support baseline refresh of I0 after filter replacement. κ and γ are stored in non-volatile storage space for retrieval.

[0015] Preferably, the carbon dioxide sensor outputs a concentration time series at a frequency of not less than once per second. The processor is configured to open an event window and perform fitting calculations when a step change in concentration is detected, using the sampled values ​​and steady-state values ​​at two times t1 and t2 to obtain the time constant, and to suppress outliers and stabilize parameters within the event window. The threshold for determining step triggering, the window duration, and the minimum number of valid samples are stored in the memory and can be called and updated by the processor.

[0016] Preferably, the first and second pressure-tapping ends of the dual-cavity differential pressure sensor are connected to the outer front cavity and the inner rear cavity of the filter via independent capillary tubes, respectively. The capillary tubes are routed along the inner wall of the housing and avoid the internal heat source and the optical path area of ​​the optical transmitting device. The processor acquires the differential pressure signal at a frequency of not less than five times per second and performs representative value extraction of the sliding median or percentile. The reference differential pressure ΔPref, the maximum allowable differential pressure ΔPmax, and the window length used for sampling and smoothing are stored in the memory and read by the processor during operation.

[0017] Preferably, the internal temperature sensor and the external temperature sensor are connected to the processor via independent buses. The power detection module is a shunt resistor sampling circuit or a power metering chip and is electrically connected to the analog-to-digital conversion unit of the processor. The processor is configured to calculate the equivalent thermal resistance based on the internal and external temperatures and the equivalent power, and generate a parameter set for channel-level temperature compensation and resource scheduling. At the same time, it stores the control priority order and corresponding threshold table of the display brightness, wireless transmission duty cycle and buzzer duty cycle in the memory, and outputs control signals according to the order and threshold table when the state machine is running.

[0018] Compared with related technologies, the indoor air quality monitoring device and sensor collaborative control system provided by the present invention have the following beneficial effects:

[0019] This invention addresses structural influences by treating them as a first-type input and unifying their parameterization. The device achieves feedforward identification and closed-loop suppression of sample introduction degradation, filter media contamination and misalignment, internal thermal drift, and acoustic attenuation. The sampling confirmation window is adaptively adjusted to reduce false alarms; channel-level temperature drift compensation and power derating are prioritized and executed collaboratively for steady-state temperature control; the alert link maintains subjective loudness consistency based on equivalent gain; and the baseline is refreshed after maintenance to maintain long-term consistency. Thus, without altering the mechanical form, the device significantly improves monitoring accuracy, stability, and alarm reachability, highlighting the value of structure-aware driven device-level design. Attached Figure Description

[0020] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0021] Figure 1 This is a three-dimensional structural diagram of the device proposed in this invention;

[0022] Figure 2 This is a schematic diagram of the device proposed in this invention from another perspective;

[0023] Figure 3 This is a three-dimensional cross-sectional structural diagram of the device proposed in this invention;

[0024] Figure 4 This is a schematic diagram showing the positional relationship between the sensor and the mounting base proposed in this invention;

[0025] Figure 5 This is a schematic diagram of the control state machine proposed in this invention.

[0026] Number in the diagram: 100 - Indoor air quality monitoring device;

[0027] 1. Base; 2. Housing; 3. Switch; 4. Display screen; 5. Filter screen; 6. First magnetic block; 7. Second magnetic block; 8. Mounting base; 9. Electrochemical sensor; 10. Semiconductor sensor; 11. Carbon dioxide sensor; 12. Power supply; 13. Buzzer; 14. Main board; 15. Dual-cavity differential pressure sensor; 16. Filter screen positioning angle sensor; 17. Optical through-beam transmitter; 18. Optical through-beam receiver; 19. Internal temperature sensor; 20. External temperature sensor; 21. Acoustic sampling sensor. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] The terminology used in this disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. The singular forms “group,” “class,” and “the” as used in this disclosure and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0030] It should be understood that although the terms first, second, third, etc., may be used in this disclosure to describe various information, such information should not be limited to these terms. These terms are used only to distinguish information of the same type from one another. For example, without departing from the scope of this disclosure, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to determination."

[0031] Example, refer to Figures 1 to 4 This invention provides an indoor air quality monitoring device 100. The device includes a base 1, a housing 2, a display screen 4, a switch 3, a main board 14, a power supply 12, a buzzer 13, and monitoring components.

[0032] Specifically, the outer casing 2 is fixed to the base 1, forming the main structure of the device. The front end face of the outer casing 2 has an arc-shaped mounting groove for accommodating the filter screen 5. To enable detachable installation of the filter screen 5, multiple second magnetic blocks 7 are equidistantly arranged along the arc-shaped edge of the mounting groove. The filter screen 5 itself or its support has a first magnetic block 6 that cooperates with the second magnetic blocks 7. Through the magnetic attraction between the first magnetic block 6 and the second magnetic blocks 7, the filter screen 5 can be easily and detachably installed in the arc-shaped mounting groove. This magnetic installation method not only facilitates filter replacement for users but also provides a structural basis for subsequent filter placement angle sensing.

[0033] The rear end and sides of the outer casing 2 are provided with heat dissipation holes for heat dissipation inside the device, ensuring the normal operating temperature of the electronic components. The rear end of the outer casing 2 also has a speaker hole corresponding to the position of the buzzer 13, for the buzzer 13 to emit an alert sound. A charging port is located on one side of the rear end of the outer casing 2, which is electrically connected to the power supply 12 inside the device for powering or charging the device. The main board 14, as the control core of the device, is electrically connected to the switch 3, display screen 4, monitoring components, power supply 12, and buzzer 13, and is responsible for receiving sensor data, processing control logic, driving display and alert functions, etc.

[0034] The core of this invention lies in the composition of its monitoring components and the structure-aware control based on the device structure. The monitoring components include the following sensors and modules:

[0035] Carbon dioxide sensor 11: Located within the sensing cavity after the arc-shaped mounting groove, it is used to acquire the time series C(t) of carbon dioxide concentration in the air. In this invention, the carbon dioxide sensor 11 is not only used for conventional concentration monitoring, but its output C(t) is also used to calculate the equivalent injection diffusion time constant. This is used to characterize the integrity and response hysteresis of the injection channel.

[0036] In some embodiments, the carbon dioxide sensor may be an infrared absorption sensor.

[0037] The dual-chamber differential pressure sensor 15 has a first pressure-taking end connected to the outer front chamber of the filter screen 5 via a capillary tube, and a second pressure-taking end connected to the inner rear chamber of the filter screen 5 via another capillary tube. This sensor is used to output the micro-pressure difference across the filter screen 5 in real time. . It is a key parameter for assessing the degree of filter clogging and is used to calculate the micro-pressure differential clogging index. .

[0038] In a preferred embodiment, the dual-cavity differential pressure sensor 15 is laid to the inner walls of the front and rear cavities of the filter screen through two capillary tubes respectively. The tubes are routed along the inner wall of the housing and avoid heat sources and optical paths to reduce additional flow resistance and measurement crosstalk, thereby ensuring the accuracy of differential pressure measurement.

[0039] Filter positioning angle sensor 16: Fixed near the filter support close to the first magnetic block 6, it outputs two magnetic induction intensity vectors B1 and B2. This sensor can sense the installation posture of the filter 5, determine whether the filter is correctly positioned or has a deviation, and calculate the filter positioning deviation angle. .

[0040] In a preferred embodiment, the filter positioning angle sensor 16 records the time after the device is assembled. , This serves as a reference vector, which is compared with the current vector during the power-on self-test phase to determine... This allows for real-time monitoring of the filter's positioning status to determine if any limits are exceeded.

[0041] Optical beam detector: Includes an optical beam emitter 17 and an optical beam receiver 18. Both are coaxially mounted inside an arc-shaped mounting slot, and their optical path penetrates the filter 5 to output transmitted light intensity I. Transmitted light intensity I is a key parameter for evaluating the optical porosity of the filter and is used to calculate the filter's optical porosity. This indicates the degree of contamination and obstruction of the filter.

[0042] In a preferred embodiment, the optical through-beam transmitter 17 and the optical through-beam receiver 18 are coaxially mounted inside the arc-shaped mounting groove. The optical path passes only through a filter and is equipped with a stray light shield to suppress external light interference and stabilize the measurement of I, thereby improving measurement accuracy.

[0043] Internal temperature sensor 19: Attached to the sensing cavity or its metal support, it is used to output the temperature Ts on the sensing cavity side. Ts is an important parameter for evaluating the internal thermal state of the device, and together with the external temperature sensor 20 and the power detection module, it is used to calculate the equivalent thermal resistance Rth between the sensor cavity and the motherboard.

[0044] In a preferred embodiment, the internal temperature sensor 19 is adhered to the metal component of the sensing cavity by thermally conductive adhesive to ensure good thermal contact and accurate temperature measurement.

[0045] External temperature sensor 20: Located on the outside of housing 2 or upstream of the air inlet, it outputs the ambient temperature Tenv. Tenv is an important parameter for evaluating the external thermal environment of the device, and together with internal temperature sensor 19 and power detection module, it is used to calculate the equivalent thermal resistance Rth.

[0046] In a preferred embodiment, the external temperature sensor 20 is located upstream of the air intake of the housing or at an external opening to accurately reflect the ambient temperature. The internal temperature sensor 19 and the external temperature sensor 20 are each connected to the motherboard 14 via independent buses to reduce the measurement phase difference caused by cross-thermal capacitance and improve the independence and accuracy of temperature measurement.

[0047] Acoustic sampling sensor 21: Located inside the rear speaker hole and facing the buzzer 13, it is used to output the root mean square sound pressure level (prms). prms is a key parameter for evaluating the buzzer's cuing effect, and together with the root mean square value of the driving voltage Vrms of the buzzer 13, it is used to calculate the buzzer's directional acoustic gain Gac.

[0048] In a preferred embodiment, the acoustic sampling sensor 21 is located in the geometric center region of the rear speaker hole and axially aligned with the buzzer 13 to improve the consistency of prms pickup and reduce measurement deviation caused by structural directivity, thereby ensuring the accuracy of acoustic gain calculation.

[0049] Power detection module: Connected in series with the heating or main energy-consuming circuit, used to output the equivalent power P. P is an important parameter for evaluating the power of the internal heat source of the device, and together with the internal temperature sensor 19 and the external temperature sensor 20, it is used to calculate the equivalent thermal resistance Rth.

[0050] In a preferred embodiment, the power detection module uses a shunt resistor or a power metering chip, which is connected in series to the heating or main energy consumption circuit. The detection signal is acquired by the analog-to-digital conversion unit of the motherboard 14 and used to calculate the equivalent power P in real time.

[0051] The device is configured as a structure-aware control system based on its structure. Without altering the relative positions of the outer casing and components, it generates structural parameters for control and maintenance and drives control logic using structural conditions defined by the arc-shaped sample inlet, magnetic filter, dual-chamber differential pressure structure, heat dissipation holes and component thermal paths, and rear speaker holes. This means that the invention is not merely a simple integration of sensors, but rather uses the physical structure of the device itself as the basis for perception and control, forming an intelligent adaptive system.

[0052] In some embodiments, the device may further include an electrochemical sensor 9 and a semiconductor sensor 10. These two are connected to the motherboard 14 as subordinate parameters and are used for maintenance prompts or environmental background verification, but do not participate in the calculation of the aforementioned structural parameters or the structural sensing control decision. This means they can provide additional air quality information without affecting the core structural sensing control logic of the present invention.

[0053] This invention calculates a series of structural parameters reflecting the structural state of the device using the raw data obtained from the aforementioned monitoring components. These structural parameters include at least:

[0054] Filter placement deviation angle : The deviation angle of filter 5 relative to the ideal mounting surface, and the two magnetic induction intensity vectors B1 and B2 output by filter positioning angle sensor 16 and their assembly reference vector. , Calculated. Specifically, It equals the value of the inverse cosine function, whose independent variable is the vector difference (B1−). ) and (B2− The dot product of the two vectors divided by the product of their norms; where the dot product represents the relative orientation of the two vectors, and the norm is used for normalization scaling. It is measured in radians. This parameter is used to determine whether filter 5 is in the correct position.

[0055] Equivalent injection diffusion time constant It is obtained by fitting the step response of the concentration time series C(t) acquired by the carbon dioxide sensor 11. Specifically, Based on the first-order response model, the following condition is satisfied: Where C0 is the initial value and C∞ is the steady-state value. Choose any two times t1 and t2. It is equal to the ratio of (t2−t1) divided by the natural logarithm [C∞−C(t1)] divided by [C∞−C(t2)]. Used to reflect the integrity and response hysteresis of the injection channel.

[0056] In a preferred embodiment, The fitting process uses the detection of a sudden increase or decrease in carbon dioxide concentration as a trigger condition to open an event window. Within the window, robust fitting or sliding median suppression of outliers is employed to improve the fitting efficiency. The stability of the carbon dioxide sensor 11 is ensured. The sampling frequency is no less than once per second. The event window duration is no less than thirty seconds to ensure that there are enough data points for accurate fitting.

[0057] Filter optical porosity The intensity of the transmitted light I output from the optical through-beam detector is obtained through calibration mapping. Specifically, Depend on The result is that κ and γ are factory calibration constants, and I0 is the reference light intensity in the state with or without a filter. Used to characterize the degree of filter contamination and obstruction.

[0058] In a preferred embodiment, the optical through-beam detector is factory-calibrated with I and ρopt, the calibration constants κ and γ are stored in non-volatile memory, and I0 serves as a baseline after filter cleaning or replacement and can be updated during operation to adapt to the new state after filter aging or replacement.

[0059] Micro-pressure differential blockage index The value is calculated based on the normalized values ​​of ΔP(t) output by the dual-chamber differential pressure sensor 15, the reference pressure difference ΔPref, and the maximum permissible pressure difference ΔPmax. Specifically, Depend on The value range is limited to between zero and one. ΔPref is calibrated under clean filter conditions, and ΔPmax is the maximum micro-pressure difference allowed by the structural design. Used to trigger filter maintenance and sampling strategy adjustments.

[0060] In a preferred embodiment, The calculation uses the moving median or percentile of ΔP(t) as a representative value to suppress the impact of short-term disturbances on the congestion index. The sampling frequency of the dual-chamber differential pressure sensor is no less than five times per second to capture the dynamic changes of micro-pressure differences.

[0061] The equivalent thermal resistance Rth between the sensor cavity and the motherboard is calculated based on the temperature difference between Ts output by the internal temperature sensor 19 and Tenv output by the external temperature sensor 20, and the equivalent power P output by the power detection module. Specifically, Rth = (Ts − Tenv) / P. Rth is used for temperature drift compensation and power derating.

[0062] In a preferred embodiment, the power detection module calculates the equivalent power P based on the shunt resistor voltage drop or the output of the power metering chip, and uses it in conjunction with Ts and Tenv to estimate Rth online and trigger derating control. The sampling frequency of the internal and external temperature sensors is no less than twice per second.

[0063] f) Buzzer directional acoustic gain Gac: Calculated based on the prms output by the acoustic sampling sensor 21, the root mean square value of the driving voltage Vrms of the buzzer 13, and the acoustic link calibration coefficient Kmic. Specifically, Gac = Kmic·(prms / Vrms). Gac is used to achieve equal-perceived loudness cues based on the characteristics of the device's aperture array.

[0064] In a preferred embodiment, the acoustic sampling sensor 21 has an internal sampling frequency of not less than 8 kHz and outputs a root mean square sound pressure level. The acoustic sampling sensor 21 is calibrated once to obtain the Kmic, and the stability of the Gac is verified when the buzzer 13 is driven by a standard test tone to assess whether the speaker hole is blocked or whether the structure is deformed.

[0065] Reference Figure 5 This invention provides an indoor air quality monitoring and control method based on a device structure, applied to the devices described in Embodiments 1 and 2 above. The method includes the following steps:

[0066] S1 Structural Parameter Acquisition: The device continuously collects raw sensor data such as B1, B2, C(t), I, ΔP(t), Ts, Tenv, prms, Vrms, and P. The motherboard 14 calculates the parameters based on these raw data using a preset algorithm and model. , , , Structural parameters such as Rth and Gac. The calculation process is as described above.

[0067] S2 injection integrity assessment: Mainboard 14 based on calculations , , , Structural parameters are used to calculate a structural health index, Iintake. Iintake is a comprehensive indicator that assesses the overall health of the device's sample inlet channel and filter. When Iintake exceeds a preset threshold, it indicates a potential problem with sample integrity, such as filter blockage, obstructed sample inlet channel, or filter misalignment. In this case, the mainboard 14 will extend the measurement reconfirmation time window and freeze the linkage for downward trends. This means that when sample integrity is compromised, the device will be more cautious in handling changes in air quality data, avoiding misjudgments caused by structural problems.

[0068] In a preferred embodiment, the structural health index Iintake is obtained by normalizing and weighting the parameters, where the weights sum to one, and for each parameter... and Using a monotonically increasing mapping, for 1− and A monotonically increasing mapping is used to ensure that Iintake accurately reflects the degree of degradation in sample integrity. When Iintake remains at a low level for an extended period, and and When Iintake is within the normal range, shorten the reconfirmation time window to improve real-time performance; when Iintake increases, extend the reconfirmation time window to reduce the risk of misjudgment.

[0069] S3 Thermal Coupling Compensation and Derating: The motherboard 14 continuously monitors Rth and P and calculates the near-end temperature change rate of the motherboard. When Rth multiplied by P or Rth multiplied by the near-end temperature change rate of the motherboard exceeds a preset threshold, it indicates a significant change in the internal thermal environment of the device, which may lead to sensor temperature drift. At this time, the motherboard 14 will perform temperature drift compensation on the gas measurement value to correct the measurement error caused by the temperature change. At the same time, in order to reduce the internal heat load, the motherboard 14 will reduce the brightness of the display screen 4, the duty cycle of wireless transmission, and the prompt duty cycle of the buzzer 13 according to priority, thereby achieving power derating scheduling. In a preferred embodiment, the temperature drift compensation satisfies: for the original measurement value zi of the i-th channel, the compensated value is zi'=zi−βi·Rth·(near-end temperature change rate of the motherboard), where βi is the temperature drift sensitivity coefficient of the corresponding channel.

[0070] S4 Acoustic Sensing Drive: The motherboard 14 calculates the required drive voltage for the buzzer 13 based on the calculated Gac and the currently detected anomaly level. By dynamically adjusting the drive voltage of the buzzer 13, the loudness perceived by the user remains constant, ensuring the effectiveness of the alert tone even if the speaker hole is blocked or the internal acoustic environment of the device changes.

[0071] In a preferred embodiment, during nighttime or quiet periods, a combination strategy of short beeping plus display screen prompts is adaptively selected based on Gac and ambient noise, and user confirmation events are recorded to optimize subsequent acoustic drive voltages, thereby achieving more intelligent prompts.

[0072] S5 Maintenance and Placement Instructions: Motherboard 14 Continuous Monitoring , and .when If the value is below the preset threshold, it indicates that the filter is clogged or severely contaminated, or A value higher than the preset threshold indicates that the filter is clogged, or If the limit is exceeded, it indicates that the filter is not correctly positioned. In this case, the main board 14 will issue a prompt for filter cleaning, replacement, or repositioning via the display screen 4 and / or buzzer 13. After the user completes the maintenance operation, the device will automatically refresh I0. Baseline and To adapt to the new filter conditions and ensure the accuracy of subsequent monitoring.

[0073] The motherboard 14 is configured to execute a control state machine with structural parameters as input. The state machine includes at least a normal state, a sample introduction degradation state, a thermal drift state, a filter misalignment state, and a maintenance state, and executes at least one of the following based on the state transition conditions: extended sampling confirmation, temperature drift compensation, power derating, positioning prompt, and maintenance guidance. For example, when... When the limit is exceeded, the state machine enters the filter misalignment state, triggering a positioning prompt; when or When the limit is exceeded, the state machine enters the maintenance state, triggering maintenance guidance; when Rth or P is abnormal, the state machine enters the thermal drift state, triggering temperature drift compensation and power derating; when In case of an anomaly, the state machine enters the sample introduction degradation state, triggering an extension of the sampling confirmation process.

[0074] This invention also provides an indoor air quality monitoring system, including a processor, a memory, and the indoor air quality monitoring device described in the above embodiments. The memory stores instructions that run on the processor, which cause the processor to execute the indoor air quality monitoring and control method described in Embodiment 3. The processor may be a microcontroller on the motherboard 14 or a more powerful processing unit. The memory may be a non-volatile storage medium such as ROM, RAM, or flash memory.

[0075] The present invention also provides a computer-readable storage medium storing a computer program. When the program is executed by a processor, it implements the steps of the indoor air quality monitoring and control method described in Embodiment 3 above. The computer-readable storage medium may be a USB flash drive, portable hard drive, optical disc, read-only memory (ROM), random access memory (RAM), magnetic tape, floppy disk, optical data storage device, etc.

[0076] 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 them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention. The formulas involved in the present invention have all been dimensionless (e.g., through standardization), and are obtained through software simulation optimization based on a large amount of sensor measurement data, which can truly reflect the relationship of air quality parameters; the preset parameters in the formulas can be flexibly set by those skilled in the art according to the actual monitoring scenario.

[0077] The above embodiments can be implemented through software, hardware, firmware, or any combination thereof. When implemented in software, it can be embodied as a computer program product, whose contained computer instructions, after being loaded and executed, can generate processes and functions such as data analysis and early warning control for air quality monitoring. The computer instructions can be stored in semiconductor media such as flash memory, EEPROM, and solid-state drives, or magnetic media such as portable hard drives and magnetic disks, or optical media such as optical discs, and can be transmitted via wired or wireless methods (such as infrared or microwave).

[0078] The execution order of each process is determined by the air quality data processing logic and the early warning response requirements, and is not limited by sequence numbers. The units and algorithm steps of this invention can be implemented by electronic hardware or a combination of hardware and software, depending on design constraints such as sensor coordination accuracy and response speed. All related implementation methods are within the protection scope of this invention.

[0079] The system unit is divided into logical functional units, which can be integrated or deployed in a distributed manner in actual implementation; modules are indirectly coupled and communicate with each other through electrical interfaces and other means. When the functions are implemented as software units and sold independently, they can be stored on computer-readable media such as USB flash drives, ROM, and RAM, and the included instructions enable the device to perform core steps such as data fusion, dynamic threshold calculation, and hierarchical early warning.

[0080] Other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of the invention are indicated by the following claims.

[0081] It should be understood that the present invention is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

Claims

1. An indoor air quality monitoring device, characterized in that, Includes a base and a housing, with the front end of the housing forming an arc-shaped mounting groove; A filter support is detachably installed in the arc-shaped mounting groove. The filter support is provided with a first magnetic block. A second magnetic block is provided at a distance from the arc-shaped front edge of the outer shell. The first magnetic block and the second magnetic block are attracted and positioned relative to each other. A carbon dioxide sensor is arranged in the sensing cavity after the arc-shaped mounting groove. The carbon dioxide sensor is used to output a concentration time series, and the concentration time series is used to calculate the equivalent injection diffusion time constant. The two pressure taps of the dual-chamber differential pressure sensor are respectively connected to the outer front cavity and the inner rear cavity of the filter screen through capillary tubes. The dual-chamber differential pressure sensor is used to output the micro pressure difference on both sides of the filter screen, and the micro pressure difference is used to calculate the micro pressure difference clogging index. An optical through-beam transmitter and an optical through-beam receiver are coaxially arranged inside the arc-shaped mounting groove to form an optical through-beam device. Its light path passes through the filter screen. The optical through-beam device is used to output transmitted light intensity I, and this transmitted light intensity I, combined with calibration constants κ and γ and reference light intensity I0, is used to calculate the filter screen optical porosity ρopt. A filter screen positioning angle sensor is arranged near the filter screen support of the first magnetic block. The filter screen positioning angle sensor is used to output two magnetic induction intensity vectors, and these vectors are used to determine the filter screen installation posture and calculate the filter screen positioning deviation angle. An internal temperature sensor is disposed on the sensing cavity or its metal support, and the internal temperature sensor is used to output the temperature Ts on the sensing cavity side; an external temperature sensor is disposed upstream of the air inlet of the housing or at the outer opening, and the external temperature sensor is used to output the ambient temperature Tenv. A power detection module is connected in series in the heating or main energy-consuming circuit of the device. The power detection module is used to output the equivalent power P, and the equivalent power P, together with the sensing cavity side temperature Ts and the ambient temperature Tenv, is used to calculate the equivalent thermal resistance. A buzzer is set at the corresponding sound hole on the rear end of the housing. An acoustic sampling sensor is set inside the sound hole and aligned with the axial direction of the buzzer. The acoustic sampling sensor is used to output the root mean square sound pressure prms, and the root mean square sound pressure prms, together with the root mean square value of the buzzer driving voltage, is used to calculate the acoustic gain. The motherboard is electrically connected to all the aforementioned sensors and modules, and is configured to calculate structural parameters based on the electrical signals measured by each sensor, and to execute a control state machine using the structural parameters as input. The control state machine includes at least a normal state, a sample introduction degradation state, a thermal drift state, a filter misalignment state, and a maintenance state. The control state machine executes at least one of the following based on the state transition conditions: extended sampling confirmation, temperature drift compensation, power derating, positioning prompt, and maintenance guidance.

2. The indoor air quality monitoring device according to claim 1, characterized in that, The optical beam transmitter and the optical beam receiver are coaxial, and their optical paths only pass through the effective area of ​​the filter. A light-shielding structure is provided inside the arc-shaped mounting slot to suppress stray incident light. The motherboard stores constants κ and γ related to the calibration of the filter's optical parameters, as well as a reference light intensity I0. The constants κ and γ are fixed in non-volatile memory. The reference light intensity I0 is updated after the filter is cleaned or replaced and is called by the motherboard as a baseline parameter for optical measurements.

3. The indoor air quality monitoring device according to claim 1, characterized in that, The first and second pressure-taking ends of the dual-cavity differential pressure sensor are respectively connected to the outer front cavity of the filter and the inner rear cavity of the filter through independent capillary tubes. The capillary tubes are wired along the inner wall of the housing and avoid the internal heat source and the optical path area of ​​the optical transmitting device. The motherboard acquires the differential pressure signal at a frequency of not less than five times per second and extracts representative values ​​of the instantaneous measurement using the sliding median or percentile. At the same time, the reference differential pressure ΔPref and the maximum allowable differential pressure ΔPmax are stored in non-volatile memory for normalization calculation.

4. The indoor air quality monitoring device according to claim 1, characterized in that, The carbon dioxide sensor is used to output a concentration time series. When the motherboard detects a step change in concentration, it opens an event window and performs fitting calculations. The sampling frequency of the carbon dioxide sensor is no less than once per second. The motherboard calculates the equivalent injection diffusion time constant based on the data at two times t1 and t2. The diffusion time constant is calculated by the following formula: Where C∞ is the steady-state concentration, and C(t1) and C(t2) are the concentration sampling values ​​at the corresponding times. The calculation is performed within the event window to suppress outliers and update parameters.

5. The indoor air quality monitoring device according to claim 1, characterized in that, The internal temperature sensor and the external temperature sensor are connected to the motherboard via independent buses. The power detection module is a shunt resistor sampling circuit or a power metering chip and is electrically connected to the analog-to-digital conversion unit of the motherboard. The motherboard calculates the equivalent thermal resistance based on the sensing cavity side temperature Ts output by the internal temperature sensor, the ambient temperature Tenv output by the external temperature sensor, and the equivalent power P output by the power detection module. The formula for calculating the equivalent thermal resistance is Rth=(Ts-Tenv) / P. The acoustic sampling sensor outputs the root mean square sound pressure at an internal sampling rate of not less than 8 kHz and is used together with the root mean square value of the driving voltage of the buzzer to calculate the acoustic gain.

6. A sensor collaborative control system for an indoor air quality monitoring device, characterized in that, The system is applied to the indoor air quality monitoring device according to any one of claims 1-5, and includes an indoor air quality monitoring device, a processor, and a memory; The indoor air quality monitoring device includes: a detachable filter screen installed in an arc-shaped mounting groove, and a first magnetic block and a second magnetic block that are adsorbed and positioned relative to the filter screen; a carbon dioxide sensor arranged in a sensing cavity after the arc-shaped mounting groove; the carbon dioxide sensor is used to output a concentration time series, and the concentration time series is used to calculate the equivalent injection diffusion time constant; and a dual-chamber differential pressure sensor whose two pressure taps are respectively connected to the front cavity outside the filter screen and the rear cavity inside the filter screen via independent capillary tubes; the dual-chamber differential pressure sensor is used to output a micro pressure difference on both sides of the filter screen, and the micro pressure difference is used to calculate the micro pressure difference blockage index. An optical through-beam emitter and an optical through-beam receiver are coaxially arranged and their optical paths pass through a filter screen. The two constitute an optical through-beam device. The optical through-beam device is used to output transmitted light intensity I, and the transmitted light intensity I, together with calibration constants κ and γ and reference light intensity I0, is used to calculate the optical porosity ρopt of the filter screen. A filter positioning angle sensor is installed near the filter support of the first magnetic block. The filter positioning angle sensor is used to output two magnetic induction intensity vectors, and these vectors are used to determine the filter installation posture and calculate the filter positioning deviation angle. An internal temperature sensor is attached to the sensing cavity or its metal support, the internal temperature sensor being used to output the sensing cavity side temperature Ts; An external temperature sensor is installed upstream of the air intake or at an external opening on the housing. The external temperature sensor is used to output the ambient temperature Tenv. A power detection module is connected in series with the heating or main energy-consuming circuit. The power detection module is used to output the equivalent power P, and the equivalent power P is used in conjunction with the sensing cavity side temperature Ts and the ambient temperature Tenv to calculate the equivalent thermal resistance. A buzzer is installed at the rear end of the housing corresponding to the speaker hole, and an acoustic sampling sensor is located inside the speaker hole and aligned with the buzzer axis. The acoustic sampling sensor is used to output the root mean square sound pressure (PRMS), and the PRMS, together with the root mean square value of the buzzer drive voltage, is used to calculate the acoustic gain. The processor and memory, as well as the aforementioned carbon dioxide sensor, dual-cavity differential pressure sensor, optical through-beam transmitter and receiver, filter positioning angle sensor, internal temperature sensor, external temperature sensor, power detection module, buzzer, and acoustic sampling sensor are electrically connected. The memory stores program instructions that run on the processor, which is configured to: acquire electrical signals from sensors and modules and calculate a set of structural parameters, including the filter placement deviation angle, the equivalent injection diffusion time constant based on the concentration time series, the filter optical porosity based on the transmitted light intensity and calibration constant, the clogging index based on the cross-filter micro pressure difference, reference pressure difference and maximum allowable pressure difference, the equivalent thermal resistance calculated from the internal temperature, external temperature and equivalent power, and the acoustic gain calculated from the acoustic sampling signal, the buzzer drive voltage and the acoustic link calibration coefficient; The structural parameter set is used as input to execute a control state machine, which includes at least a normal state, a sample introduction degradation state, a thermal drift state, a filter misalignment state, and a maintenance state. The control state machine is configured to manage the sampling confirmation time window, obtain channel-level temperature compensation parameters, derating and sorting control of display brightness, wireless transmission duty cycle, and buzzer duty cycle, and generate control signals for maintenance and positioning prompts based on preset thresholds and mappings, and send the control signals to the display screen, the wireless communication interface, and the buzzer, respectively.

7. The sensor collaborative control system for an indoor air quality monitoring device according to claim 6, characterized in that, The optical beam transmitter and the optical beam receiver are coaxial, and their optical paths only pass through the effective area of ​​the filter. A light-shielding structure is provided inside the arc-shaped mounting slot. The memory stores constants κ and γ related to optical measurements, as well as a reference light intensity I0. The processor is configured to calculate the optical porosity of the filter according to the mapping relationship between the transmitted light intensity I and the reference light intensity I0, and to support baseline refresh of the reference light intensity I0 after filter replacement. The constants κ and γ are stored in non-volatile storage space for retrieval.

8. The sensor collaborative control system for an indoor air quality monitoring device according to claim 6, characterized in that, The carbon dioxide sensor outputs a concentration time series at a frequency of not less than once per second. The processor is configured to open an event window and perform fitting calculations when a step change in concentration is detected, using the sampled values ​​and steady-state values ​​at two times t1 and t2 to calculate the time constant. Within the event window, outliers are suppressed and parameters are stabilized. The threshold for determining step triggering, the window duration, and the minimum number of effective samples are stored in the memory and can be called and updated by the processor.

9. The sensor collaborative control system for an indoor air quality monitoring device according to claim 6, characterized in that, The first and second pressure-taking ends of the dual-cavity differential pressure sensor are respectively connected to the outer front cavity of the filter and the inner rear cavity of the filter via independent capillary tubes. The capillary tubes are wired along the inner wall of the housing and avoid the internal heat source and the optical path area of ​​the optical transmitting device. The processor acquires the differential pressure signal at a frequency of not less than five times per second and performs representative value extraction of the sliding median or percentile. The reference differential pressure ΔPref, the maximum allowable differential pressure ΔPmax, and the window length used for sampling and smoothing are stored in the memory and read by the processor during operation.

10. The sensor collaborative control system for an indoor air quality monitoring device according to claim 6, characterized in that, The internal temperature sensor and the external temperature sensor are respectively connected to the processor via independent buses. The power detection module is a shunt resistor sampling circuit or a power metering chip and is electrically connected to the analog-to-digital conversion unit of the processor. The processor is configured to calculate the equivalent thermal resistance based on the sensing cavity side temperature Ts output by the internal temperature sensor, the ambient temperature Tenv output by the external temperature sensor, and the equivalent power P output by the power detection module, and generate a parameter set for channel-level temperature compensation and resource scheduling. At the same time, it stores the control priority order and corresponding threshold table of display brightness, wireless transmission duty cycle and buzzer duty cycle in the memory and outputs control signals in sequence according to the threshold table when the state machine is running.

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