A surface acoustic wave OPSM sensor device design method and application system

Abstract

The application provides a surface acoustic wave OPSM sensor device design method and application system, belongs to the field of indoor environment monitoring, solves the problem of carbon dioxide detection, and has the technical scheme that comprises the following steps: S10, giving the parameters of the surface acoustic wave OPSM sensor device; S20, generating k groups of initial finger sequences and calculating the frequency response point set and total evaluation value of each group of fingers; S30, calculating the total result value of the finger sequence with the minimum total evaluation value; if the total result value is 0, the cycle is ended; otherwise, the finger sequence is modified and the total evaluation value is calculated. The application has the beneficial effects that the design cost of the surface acoustic wave OPSM sensor device is reduced, the carbon dioxide gas detection efficiency is improved, and the application can be easily popularized to other surface acoustic wave devices.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of indoor environment monitoring such as libraries, reading rooms, self-study classrooms, and specifically relates to a surface acoustic wave OPSM sensor device design method and application system. BACKGROUND

[0002] In libraries, reading rooms, self-study classrooms, etc., when there are many readers and indoor ventilation is poor for a long time, the indoor carbon dioxide (CO2) concentration will gradually exceed the standard, leading to situations such as brain hypoxia, dizziness, chest tightness, and shortness of breath, which seriously threaten people's health. People in enclosed spaces may ignore the potential source of carbon dioxide while using air conditioners for a long time and being busy with learning and work, and convenient living conditions also pose potential health risks. Carbon dioxide is a colorless, odorless, and non-irritating gas that is difficult for people to detect. Long-term exposure to high concentrations of carbon dioxide in the environment can pose serious health risks to people and even endanger their lives.

[0003] Currently, a common method for monitoring indoor carbon dioxide concentration is through fixed alarms installed on walls. Although this method can provide some safety warnings, it has many shortcomings. It can only issue an alarm when the concentration is high, cannot provide real-time concentration data, and has limited sensitivity and accuracy, which can easily result in false alarms or missed alarms. There is a lack of an efficient monitoring system to quantitatively measure indoor carbon dioxide concentration and provide accurate monitoring results in a timely manner to ensure the safety of indoor environments such as libraries, reading rooms, and self-study classrooms.

[0004] Therefore, the present application provides a surface acoustic wave OPSM sensor device design scheme for a carbon dioxide detection system in an indoor environment, achieving high-precision and rapid-response carbon dioxide monitoring. SUMMARY

[0005] The present application provides a surface acoustic wave OPSM sensor device design method and application system, which calculates a theoretical frequency response point set , an actual frequency response point set , and , randomly generates an initial group of finger strip sequences, evaluates the frequency response using a total evaluation value, judges the frequency response with the smallest total evaluation value, ends the loop when the total result value is 0, otherwise modifies the original group of finger strip sequences and recalculates the total evaluation value, obtains the design result of the surface acoustic wave OPSM sensor device, and is used in a carbon dioxide gas monitoring system, presenting the advantages of rapid response, high sensitivity, and high stability, and having strong practical value.

[0006] To achieve the above-mentioned application purposes, the technical scheme adopted by the present application is as follows:

[0007] A design method of a surface acoustic wave OPSM (Optimal Point Set Matching) sensor device, characterized by comprising the following steps:

[0008] S10, giving parameters of the surface acoustic wave OPSM sensor device, center frequency , frequency , finger sequence , determining the objective function and the frequency point set;

[0009] S20, generating group initial finger sequence, calculating the frequency response point set and the total evaluation value of each group of fingers , the total evaluation value reflects the performance index bandwidth and the pros and cons of out-of-band suppression;

[0010] S30, calculating the total result value of the finger sequence with the smallest total evaluation value , if 0, end the loop, otherwise modify the finger sequence and calculate the total evaluation value.

[0011] The step S10 comprises the following steps:

[0012] S11, the range of frequency is , where is the center frequency, is a constant, and the frequency points are taken at intervals of , and is a constant, to obtain the frequency point set and , the range of the frequency point set is , the range of the frequency point set is , is a constant and ;

[0013] Further, the step S20 comprises the following steps:

[0014] S21, calculating group initial finger sequence, the value of the th finger in the th finger sequence is determined by the judgment value , , if 0, the finger is not retained, and if 1, the finger is retained;

[0015] (1);

[0016] (2);

[0017] wherein, is a prime number and satisfies the condition , is the total number of the group of fingers;

[0018] S22, the frequency corresponding theoretical frequency response and actual frequency response , the frequency point set corresponding theoretical frequency response point set and actual frequency response point set , the frequency point set corresponding actual frequency response point set , calculate and the absolute difference set at the corresponding frequency , , is a constant;

[0019] S23, for each group of finger sequence , traverse the set and compare with , if greater than replace , is a constant and , calculate the bandwidth evaluation value and out-of-band suppression evaluation value , finally calculate the total evaluation value ,

[0020] (3);

[0021] (4);

[0022] (5);

[0023] (6);

[0024] wherein, , , is a constant, is the absolute difference set of and , the maximum value in the actual frequency response point set , the target value of the out-of-band suppression;

[0025] Further, the step S30 comprises the following steps:

[0026] ​​S31. Calculate the bandwidth result for the index bar sequence with the minimum total evaluation value. and out-of-band suppression results ,try to find The minimum value in, It is an array that stores the minimum total score. The number of iterations is used to calculate the evaluation result value. and total result value ,

[0027] (7);

[0028] (8);

[0029] (9);

[0030] (10);

[0031] in, It is the set of absolute differences The minimum value in, It is a set The maximum value in, It is the target value for out-of-band suppression;

[0032] S32, Generate new The finger strip sequence is processed using a dynamic inheritance strategy. In each iteration, the finger strip sequence with the lowest total evaluation value is retained and inherited to the next iteration. The total evaluation value of the finger strip sequence is then used to determine the next iteration. Calculate probability Repeatedly and randomly select a set of finger strip sequences, generate random numbers and... Compare, if greater than Keep it, otherwise don't keep it.

[0033] (11);

[0034] S33, Amendment Group finger strip sequences, randomly select two finger strip sequences, and generate random numbers. , , exchange the to Root bar; randomly select the first bar The first in the group finger sequence Root bar, generate random numbers and match them with Comparison, greater than The first The first in the group finger sequence Root bar value Modified to Otherwise, no changes will be made.

[0035] (12);

[0036] (13);

[0037] wherein, , is the minimum total evaluation value, is the average total evaluation value of all the sequences of the index bar less than the average total evaluation value.

[0038] The application provides another technical scheme, comprising: a sensor characterized by comprising a surface acoustic wave OPSM sensor device based on multi-target dynamic inheritance, which is designed by using the design method and is used for an indoor carbon dioxide detection system.

[0039] Further, the sensor comprises a carbon dioxide measurement input module, a carbon dioxide measurement output module and a data processing module, wherein the carbon dioxide measurement input module comprises carbon dioxide and the surface acoustic wave OPSM sensor device; the carbon dioxide measurement output module comprises a display screen and an alarm; and the data processing module comprises an amplifier, a frequency mixer and a microcontroller.

[0040] The application provides still another technical scheme, comprising: an indoor carbon dioxide detection system characterized by comprising the sensor.

[0041] Compared with the prior art, the application has the following beneficial effects:

[0042] The application divides a theoretical frequency response point set, evaluates the advantages and disadvantages of the index bar sequence corresponding to the frequency response according to the total evaluation value, and ends the loop when the index bar sequence corresponding to the minimum total evaluation value has a total result value of 0, so that the surface acoustic wave OPSM sensor device with a specific frequency response can be designed flexibly according to requirements, the evaluation standard is accurately quantified, the manual intervention in the design process is reduced based on multi-target comprehensive optimization, and the design efficiency and reliability are improved. BRIEF DESCRIPTION OF DRAWINGS

[0043] Figure 1 It is a design method of a surface acoustic wave OPSM sensor device.

[0044] Figure 2 It is a design method of a surface acoustic wave OPSM sensor device.

[0045] Figure 3 It is a design method of a surface acoustic wave OPSM sensor device.

[0046] Figure 4A sensor structure schematic diagram with a gas sensitive film in a surface acoustic wave OPSM sensor device design method and application system of the present application. Figure 5 A component structure diagram of a carbon dioxide monitoring system of a surface acoustic wave OPSM sensor device based on multi-target dynamic inheritance of the present application.

[0047] In the figure, 1, input transducer; 2, output transducer; 3, gas sensitive film; 4, carbon dioxide measurement input module; 5, data processing module; 6, carbon dioxide measurement output module. DETAILED DESCRIPTION

[0048] In order to more clearly illustrate the specific technical solutions of the embodiments of the present application, the present application will be further described below in combination with the embodiments and the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. In order to make the purpose, technical solutions and advantages of the present application more clear and obvious, the present application will be further described in detail below in combination with the drawings and embodiments. Of course, the specific embodiments described here are only used to explain the present application, and are not used to limit the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application. The implementation of the present application, a surface acoustic wave OPSM sensor device design method and application system, is as follows:

[0049] Referring to Figures 1-3 The present application provides a technical solution, a surface acoustic wave OPSM sensor device design method, comprising the following steps:

[0050] S10, the parameters of the surface acoustic wave OPSM sensor device are given, the substrate material is 128° Y-X lithium tantalate, and the parameters of the material are propagation speed , electromechanical coupling coefficient , center frequency , frequency , finger sequence , target function Morlet wavelet function, scale is 2 -2 , determine the frequency point set .

[0051] S20, generate group initial finger sequence, calculate the frequency response point set and total evaluation value of each group of fingers , the total evaluation value reflects the advantages and disadvantages of the performance indicators bandwidth and out-of-band suppression;

[0052] S30, calculate the total result value of the finger sequence with the minimum total evaluation value , if the total result value is 0, end the loop, otherwise modify the finger sequence and calculate the total evaluation value.

[0053] The step S10 comprises the following steps:

[0054] S11, the frequency is in the range of , the unit is , is the center frequency, and the frequency points are taken with an interval of to obtain a frequency point set and , is in the range of , is in the range of ;

[0055] The step S20 comprises the following steps:

[0056] S21, calculate a group of initial finger sequence, the th finger sequence in the th group of finger sequence is determined by the decision value , when the value is 0, the finger is not retained, and when the value is 1, the finger is retained;

[0057] (1);

[0058] (2);

[0059] wherein is a prime number and satisfies the condition , is the total number of fingers in the group;

[0060] S22, the frequency corresponds to the theoretical frequency response and the actual frequency response , the frequency point set corresponds to the theoretical frequency response point set and the actual frequency response point set , the frequency point set corresponds to the actual frequency response point set , and the absolute difference value set and at the corresponding frequency is calculated , , is a constant;

[0061] S23, for each group of finger sequence , the set is traversed and compared with , and if greater than , the finger sequence is retained.then replace , is a constant and , the bandwidth evaluation value and the out-of-band suppression evaluation value are calculated, and finally the total evaluation value ,

[0062] (3) ;

[0063] (4) ;

[0064] (5) ;

[0065] (6) ;

[0066] wherein, , , is a constant, is the absolute difference set and , the maximum value in the actual frequency response point set , the target value of the out-of-band suppression; The step S30 includes the following steps:

[0067] S31, the minimum total evaluation value of the finger sequence is calculated to obtain the bandwidth result value and the out-of-band suppression result value

[0068] , find the minimum value in , the array that saves the minimum total evaluation value, is the iteration number, the evaluation result value and the total result value are calculated, ,

[0069] (7) ;

[0070] (8) ;

[0071] (9) ;

[0072] (10) ;

[0073] wherein, is the minimum value in the absolute difference set , the maximum value in the set , the maximum value in the set , the maximum value in the set ​​It is the target value for out-of-band suppression;

[0074] S32, Generate new The finger strip sequence is processed using a dynamic inheritance strategy. In each iteration, the finger strip sequence with the lowest total evaluation value is retained and inherited to the next iteration. The total evaluation value of the finger strip sequence is then used to determine the next iteration. Calculate probability Repeatedly and randomly select a set of finger strip sequences, generate random numbers and... Compare, if greater than Keep it, otherwise don't keep it.

[0075] (11);

[0076] S33, Amendment Group finger strip sequences, randomly select two finger strip sequences, and generate random numbers. , , exchange the to Root bar; randomly select the first bar The first in the group finger sequence Root bar, generate random numbers and match them with Comparison, greater than The first The first in the group finger sequence Root bar value Modified to Otherwise, no changes will be made.

[0077] (12);

[0078] (13);

[0079] in, , It is the minimum overall evaluation value. It is the average total evaluation value of all index sequences that are less than the average total evaluation value.

[0080] Specific embodiment 1 is shown in Table 1.

[0081] {-98.4618,-96.4421,⋯,-0.04186,-0.01046,0,-0.01046,-0.04186,⋯,-96.4421,-98.4618},

[0082] {-39.72990887, -39.61786417, -39.2191016, -38.49900311, -37.5006666,..., -40.21750495, -40.51123163, -40.97816958, -41.64464846, -42.54594487},

[0083] {-54.81863381, -55.08700025, -55.26342146,..., -39.4830658, -39.64928889} U {-43.73151745, -45.2697647, -47.23968133,..., -59.08450607, -58.82889325}.

[0084] Table 1 is Value updating process

[0085] Finger sequence number Initial value Value after 1 update … Value after 151 updates 1 440.765793 400.2821 … 427.2015 2 427.2015416 427.2015 … 440.7658 … 427.2015416 440.7658 … 427.2015 180 440.765793 427.2015 … 427.2015 181 427.2015416 440.7658 … 400.2821 Judje = 1 Judje = 1 … Judje = 0

[0086] As Figure 4 shown is a schematic diagram of a surface acoustic wave OPSM sensor device with a gas sensitive film, the middle of which is a gas sensitive film with high selectivity adsorption capacity for carbon dioxide, which will cause changes in physical properties such as mass and elastic modulus when in contact with carbon dioxide, causing changes in the phase of the surface acoustic wave.

[0087] As Figure 5 shown, a surface acoustic wave OPSM sensor device based on multi-target dynamic inheritance is used for a carbon dioxide measurement alarm system in the home, including a carbon dioxide measurement input module, a carbon dioxide measurement output module, and a data processing module.

[0088] The carbon dioxide measurement input module includes a first surface acoustic wave sensor and a second surface acoustic wave sensor; the first surface acoustic wave sensor is a surface acoustic wave OPSM sensor device with a gas sensitive film with high adsorption capacity for carbon dioxide; the second surface acoustic wave sensor is also a surface acoustic wave OPSM sensor device without a gas sensitive film, and the rest of the structure is the same as that of the first surface acoustic wave sensor, used to compensate for the influence of environmental factors (such as temperature, humidity, etc.) on the surface acoustic wave.

[0089] The data processing module includes a first amplifier, a second amplifier, a frequency mixer, and a microcontroller. The first amplifier and the second amplifier amplify the signals output by the first SAW sensor and the second SAW sensor, compensating for losses during signal acquisition. The frequency mixer mixes the signals from the first amplifier and the second amplifier, generating a difference frequency signal that contains phase change information related to the concentration of carbon dioxide. The difference frequency signal is then sent to the microcontroller for processing. The microcontroller receives the difference frequency signal, runs a data processing algorithm, and calculates the concentration of carbon dioxide.

[0090] The carbon dioxide measurement output module includes a display screen and an alarm. The display screen displays the concentration of carbon dioxide calculated by the microcontroller in real time. When the microcontroller detects that the concentration of carbon dioxide exceeds a set safety threshold, it triggers the alarm, reminding the user to take timely measures.

[0091] The microcontroller of the measurement system is an STM32. Its high-performance processing capability, low power consumption, and rich peripherals and memory configurations make it efficient in processing signals from SAW sensors, quickly calculating the concentration of carbon dioxide, and triggering an alarm in a timely manner when the concentration exceeds a set threshold. In addition, the low power consumption of the STM32 ensures the long-term stable operation of the system, adapting to the long-term monitoring needs in a home environment.

[0092] A working method of a carbon dioxide detection system of a SAW OPSM sensor device includes the following steps: carbon dioxide enters the first SAW sensor and the second SAW sensor. The gas-sensitive film of the first SAW sensor adsorbs carbon dioxide, ultimately causing a phase change in the SAW. The second SAW sensor is not coated with a gas-sensitive film and is used to compensate for the interference of environmental factors (such as temperature and humidity) on the detection results. The signal of the first SAW sensor is amplified by the first amplifier and then enters the frequency mixer. The signal of the second SAW sensor is amplified by the second amplifier and then enters the frequency mixer. The frequency mixer mixes the two signals, generating a difference frequency signal that contains phase change information related to the concentration of carbon dioxide. The difference frequency signal is then sent to the microcontroller (STM32) for processing, calculating the concentration of carbon dioxide and displaying the calculated concentration of carbon dioxide in real time through the display screen. Finally, when the concentration of carbon dioxide exceeds a set safety threshold, the alarm is triggered.

[0093] The above is a preferred embodiment of the present application. It should be noted that those skilled in the art can make several improvements and refinements without departing from the principles of the present application. These improvements and refinements should also be considered within the scope of the present application.

Claims

1. A design method for a surface acoustic wave (OPSM) sensor, characterized in that, The method comprises the following steps: S10, give the parameters of the surface acoustic wave OPSM sensor device, center frequency , frequency , index strip sequence , determine the target function and the frequency point set; S20, generating group initial finger sequence, calculate the frequency response point set and total evaluation value of each group of fingers The total evaluation value reflects the pros and cons of the performance indicators bandwidth and out-of-band suppression; wherein, comprising the following steps: S21, compute group initial finger sequence, the group finger sequence, the value of the root finger determined by the decision value determined, 0 when the finger is not retained, and 1 when the finger is retained; (1)； (2)； wherein is a prime number and satisfies the condition , is the total number of fingers; S22, frequency corresponding theoretical frequency response and actual frequency response , frequency point set corresponding theoretical frequency response point set and actual frequency response point set , frequency point set corresponding actual frequency response point set , calculate and absolute difference set at corresponding frequency , , constant; S23. For each group of finger strip sequences traverse the set and Compare, if greater than Then replace with , is a constant and Calculate bandwidth evaluation value and out-of-band inhibition evaluation value Finally, calculate the total evaluation value. , (3)； (4)； (5)； (6)； wherein, , , is a constant, is and is a set of absolute difference values, is a maximum value in a set of actual frequency response points , is a target value for out-of-band rejection; S30, calculating a total result value for the finger sequence with the minimum total evaluation value If the result is 0, the loop is ended, otherwise the finger sequence is modified and the total evaluation value is calculated; wherein, the steps include: S31, compute bandwidth result value for the minimum total evaluation value and the out-of-band suppression result value find the minimum value in , is an array that holds the minimum total evaluation value, is the number of iterations to compute the evaluation result value and the total result value , (7)； (8)； (9)； (10)； in, It is the set of absolute differences The minimum value in, It is a set The maximum value in, It is the target value for out-of-band suppression; S32, generating a new group of finger sequences, using a dynamic inheritance strategy, retaining the finger sequence with the minimum total evaluation value in each iteration and inheriting it to the next iteration; according to the total evaluation value of the finger sequence calculating the probability , repeating the random selection of a group of finger sequences, generating a random number and comparing it with if greater than retaining, otherwise not retaining, (11)； S33, modify group of fingers, randomly select two sequences of fingers, generate a random number , , exchange the first to root finger; randomly select the first group of fingers, the first root finger, generate a random number and compare with , greater than the first group of fingers, the first root finger value modified to , otherwise not modified, (12)； (13)； wherein , is the minimum total rating value, is the average total rating value of all the sequences of fingerings that are less than the average total rating value.

2. The design method of a surface acoustic wave OPSM sensor device according to claim 1, wherein, The step S10 comprises the following steps: S11, Frequency The range is ,in For the center frequency, As a constant, with Frequency points are selected at intervals. As a constant, the frequency point set is obtained. and Frequency point set The range is Frequency point set Scope , is a constant and .

3. A sensor, characterized by The application discloses a multi-target dynamic inheritance-based surface acoustic wave OPSM sensor device designed by using the design method of claim 1 and used for an indoor carbon dioxide detection system.

4. A sensor according to claim 3, wherein, The sensor comprises a carbon dioxide measurement input module, a carbon dioxide measurement output module and a data processing module, wherein the carbon dioxide measurement input module comprises carbon dioxide and a surface acoustic wave OPSM sensor device; the carbon dioxide measurement output module comprises a display screen and an alarm; and the data processing module comprises an amplifier, a frequency mixer and a microcontroller.

5. An indoor carbon dioxide detection system characterized by, The application discloses a sensor.

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