CN113391660A - Double closed loop dew point tracking control method for quartz resonance type dew point sensor - Google Patents
Double closed loop dew point tracking control method for quartz resonance type dew point sensor Download PDFInfo
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- CN113391660A CN113391660A CN202110648011.0A CN202110648011A CN113391660A CN 113391660 A CN113391660 A CN 113391660A CN 202110648011 A CN202110648011 A CN 202110648011A CN 113391660 A CN113391660 A CN 113391660A
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- dew point
- temperature
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- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
- G05D23/00—Control of temperature
- G05D23/19—Control of temperature characterised by the use of electric means
- G05D23/20—Control of temperature characterised by the use of electric means with sensing elements having variation of electric or magnetic properties with change of temperature
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N25/00—Investigating or analyzing materials by the use of thermal means
- G01N25/56—Investigating or analyzing materials by the use of thermal means by investigating moisture content
- G01N25/66—Investigating or analyzing materials by the use of thermal means by investigating moisture content by investigating dew-point
Abstract
The invention relates to a double closed loop dew point tracking control method for a quartz resonance type dew point sensor, which comprises the steps of utilizing a semiconductor refrigerator to actively control the temperature of a quartz wafer, generating moisture condensation on the surface of the quartz wafer when the temperature is reduced to the dew point temperature, changing an output signal of a resonance circuit from an initial sine signal to a direct current bias signal, designing a signal conditioning circuit to convert an intermittent sine signal into a square signal to be sent to a temperature controller, designing a rectifying and filtering circuit to convert the intermittent sine signal into a direct current signal, and sending the direct current signal to the temperature controller by obtaining an amplitude digital quantity through an analog-to-digital converter in order to accurately capture the sudden change of the signal; the logic level and the amplitude are used as feedback signals of the temperature controller, and the temperature controller outputs pulse width modulation signals according to the feedback signals to control the switch driving circuit to drive the semiconductor refrigerator to refrigerate the quartz wafer, so that double closed-loop dew point tracking control of circuit output signals and temperature is realized.
Description
The technical field is as follows:
the invention relates to a control method for dew point tracking, in particular to a double-closed-loop dew point tracking control method for a quartz resonant dew point sensor.
Background art:
humidity is an important parameter of the atmosphere, and humidity measurement plays an important role in the meteorological field. Humidity is one of the most difficult parameters to be measured accurately in conventional environmental measurement parameters because humidity is not a relatively independent measurement, it is affected by temperature, atmospheric pressure, etc., and there is a complex coupling relationship between them, so that a dew point sensor for measuring humidity is required to have characteristics of high sensitivity and rapid response.
In the dew point identification method based on the vibration stopping method, the control system simply increases and decreases the temperature at a constant speed according to whether the vibration of the quartz wafer stops or not so as to control the temperature of the quartz wafer to be maintained near the dew point. Under the control mode, when the dew point is measured for the first time or the dew point is greatly changed, a long time is needed to position a new dew point, and the control system has no self-adaptability and cannot meet the requirement of continuously tracking and measuring the dew point quickly and stably.
The invention content is as follows:
the invention aims to provide a double-closed-loop dew point tracking control method for a quartz resonance type dew point sensor, which is used for realizing quick positioning and continuous tracking measurement of a dew point.
The above object of the present invention is achieved by the following technical solutions:
the specific technical scheme is shown in figure 1. The invention provides a double closed loop dew point tracking control method for a quartz resonance type dew point sensor, which comprises the steps of utilizing a semiconductor refrigerator to actively control the temperature of a quartz wafer, generating moisture condensation on the surface of the quartz wafer when the temperature is reduced to the dew point temperature, changing an output signal of a resonance circuit from an initial sinusoidal signal to a direct current bias signal, designing a signal conditioning circuit to convert an intermittent sinusoidal signal into a square wave signal and sending the square wave signal to a temperature controller in order to accurately capture the sudden change of the signal, wherein the sinusoidal oscillation state corresponds to a high level signal, and the direct current bias state corresponds to a low level signal; designing a rectification filter circuit to convert the intermittent sinusoidal signal into a direct current signal, and sending the direct current signal to a temperature controller by obtaining amplitude digital quantity through an analog-to-digital converter; the conversion and the amplitude of the logic level are used as feedback signals of the temperature controller, and the temperature controller outputs pulse width modulation signals according to the feedback signals to control the switch driving circuit to drive the semiconductor refrigerator to refrigerate the quartz wafer, so that the active temperature control of the quartz wafer is realized. And finally, establishing a double closed-loop tracking control model of circuit output signals and temperature by taking the resonant circuit system as an inner loop and the dew point temperature tracking system as an outer loop.
The control method is realized based on an automatic test control system of a quartz resonance type dew point sensor, a specific control strategy is shown in figure 2, and when the system is operated for the first time, if the logic level of the oscillation state of a corresponding resonance circuit is high, the amplitude of a quartz wafer at the moment is recorded as the initial amplitude; during the first temperature reduction, the measuring system takes the amplitude of the quartz wafer as the basis to ensure that the temperature reduction rate is a fixed value when the temperature approaches the dew point. Meanwhile, the measurement system records the amplitude data of the quartz wafer every other one second in the cooling process until the quartz wafer stops vibrating, and the median of the amplitude data within 10 seconds before the quartz wafer stops vibrating is taken as the critical amplitude of the vibration stopping; after the initial amplitude and the oscillation stopping critical amplitude are obtained, the system starts formal measurement, firstly, if the logic level is high, the quartz wafer is not condensed, whether the amplitude of the quartz wafer is close to the initial amplitude needs to be judged, if the amplitude of the quartz wafer is different from the initial amplitude by 0.1V, the difference between the current temperature and the dew point temperature is large, and then the temperature is rapidly reduced; otherwise, judging whether the amplitude of the quartz wafer is close to the oscillation stopping critical amplitude, if the difference between the amplitude of the quartz wafer and the oscillation stopping critical amplitude is 0.1V, cooling at an extremely slow speed; if the amplitude of the quartz wafer is between the initial amplitude and the oscillation stopping critical amplitude, slowly reducing the temperature; if the logic level is low, the resonance circuit stops vibrating and the temperature is increased at a slow speed; when the low level duration time exceeds 10 seconds, the difference between the current temperature and the dew point temperature is considered to be large, and the temperature is increased at a high speed; and when the logic level is rapidly turned over in unit time, the dew point temperature is considered to be reached at the moment, and the temperature average value in the turning time is taken as the dew point temperature value to be output.
The initial amplitude is the amplitude of a sinusoidal signal output by the sensitive driving circuit under the natural state of the quartz wafer.
The oscillation stop critical amplitude is an amplitude of the quartz wafer at the time of oscillation stop due to dew condensation.
The automatic test control system of the quartz resonance dew point sensor is an automatic test control system which consists of a sensor detection module, a sensitive circuit module, a processor module, a temperature measurement module and a temperature control module, and the specific hardware system composition has already applied for invention patent (application number: ZL 201710205307.9); the function of the invention is to provide a hardware function carrier for realizing the control method of the invention.
The invention has the advantages and effects that:
according to the invention, the difference between the amplitude of the quartz wafer and the initial amplitude and the vibration stopping critical amplitude is compared under different quartz wafer oscillation states, and different refrigeration rates or heating rates are selected to refrigerate or heat the quartz wafer, so that the sensor can rapidly position the dew point, and thus double closed loop tracking measurement of the dew point is realized. The invention has the characteristics of high sensitivity, high measurement speed and strong anti-interference capability.
Description of the drawings:
fig. 1 is a technical scheme of a double closed loop dew point tracking control method for a quartz resonance type dew point sensor.
FIG. 2 is a flow chart of a dual closed loop dew point tracking control method.
FIG. 3 test effect of dew point tracking control.
The specific implementation mode is as follows:
the present invention will be described in further detail with reference to the accompanying drawings and examples.
Example (b):
fig. 1 is a technical scheme of a double closed loop dew point tracking control method of a quartz resonance type dew point sensor in the embodiment of the invention. Referring to fig. 1, the automatic test control system based on which the dual-closed-loop dew point tracking control method for the quartz resonant dew point sensor provided in this example is specifically includes: the quartz wafer generates a sinusoidal signal with the frequency of 4MHz through a sensitive driving circuit in a dry state and generates a direct current bias signal in a condensation state; the intermittent sinusoidal signal is converted into a square wave signal through a signal conditioning circuit, namely the logic level is high when the wafer is dry and the logic level is low when the wafer is in a condensation state; converting the intermittent sinusoidal signal into a direct current signal through a rectifying and filtering circuit, and obtaining an amplitude digital quantity from the direct current signal through an analog-to-digital converter; the amplitude digital quantity and the square wave signal are used as feedback signals to be sent to a temperature controller, and the temperature controller outputs a pulse width modulation signal to drive a semiconductor refrigerator to refrigerate the quartz wafer; the temperature sensor measures the temperature of the quartz wafer, and the temperature data is output and displayed by the computer.
FIG. 2 is a flow chart of a dual closed loop dew point tracking control method for a quartz resonant dew point sensor in an embodiment of the invention; FIG. 3 is a graph showing the experimental effect of the dual closed-loop dew point tracking control method for the quartz resonant dew point sensor according to the embodiment of the present invention, wherein the amplitude data in FIG. 3 is enlarged and plotted by 10 times for easy observation; the sampling period of the data in fig. 3 is 0.2 seconds. Referring to fig. 2 and fig. 3, the method for tracking and controlling a dual closed-loop dew point of a quartz resonant dew point sensor provided in this embodiment may specifically include: after the system is started, if the logic level corresponding to the oscillation state of the resonant circuit is high, recording the amplitude of the quartz wafer at the moment as the initial amplitude, wherein the test value is 1.82V; during the first temperature reduction, the measuring system takes the amplitude of the quartz wafer as the basis to ensure that the temperature reduction rate is a fixed value of 0.02 ℃/s when the temperature approaches the dew point. Simultaneously, the measuring system records the amplitude data of the quartz wafer once every 1 second in the cooling process until the quartz wafer stops vibrating, the median of the amplitude data in 10 seconds before the quartz wafer stops vibrating is taken as the critical amplitude of the vibration stopping, and the test value is 1.49V; after the initial amplitude and the oscillation stopping critical amplitude are obtained, the system starts formal measurement, firstly, if the logic level is high, the quartz wafer is not condensed, if the difference between the crystal oscillator amplitude and the initial amplitude of 1.82V is less than 0.1V, the difference between the current temperature and the dew point temperature is large, and then the temperature is rapidly reduced by 0.2 ℃/s; otherwise, judging whether the difference between the amplitude of the quartz wafer and the oscillation stopping critical amplitude is less than 0.2V, if so, indicating that the amplitude is close to the oscillation stopping critical amplitude, and cooling at an extremely slow speed of 0.02 ℃/s; if the amplitude of the quartz wafer is between the initial amplitude and the oscillation stopping critical amplitude, the temperature is reduced at a slow speed of 0.1 ℃/s; if the logic level is low, the resonance circuit stops vibrating and the temperature is increased at a slow speed of 0.1 ℃/s; when the low level duration time exceeds 10 seconds, the difference between the current temperature and the dew point temperature is considered to be large, and the temperature is increased at a high speed of 0.2 ℃/s; when the logic level is continuously turned over for 5 times or more in 1 second, the dew point temperature is considered to be reached at the moment, and the temperature mean value in the turning time is taken as the dew point temperature value to be output; fig. 3 shows the effect of the dew point tracking control test performed according to the present invention, and it can be seen that it takes 4 minutes from the system start-up to the first dew point positioning, the minimum time required to position the dew point again is 114s when the dew point changes, and good tracking of the dew point is achieved.
Claims (5)
1. A double closed loop dew point tracking control method for a quartz resonant dew point sensor is characterized by comprising the following steps: the semiconductor refrigerator is utilized to actively control the temperature of the quartz wafer, moisture condensation can be generated on the surface of the quartz wafer along with the temperature reduction to the dew point temperature, the output signal of the resonance circuit is changed from the initial sinusoidal signal to the direct current bias signal, and in order to accurately capture the sudden change of the signal, a signal conditioning circuit is designed to convert the intermittent sinusoidal signal into the square wave signal and send the square wave signal to the temperature controller, wherein the sinusoidal oscillation state corresponds to a high level signal, and the direct current bias state corresponds to a low level signal; designing a rectification filter circuit to convert the intermittent sinusoidal signal into a direct current signal, and sending the direct current signal to a temperature controller by obtaining amplitude digital quantity through an analog-to-digital converter; the conversion and the amplitude of the logic level are used as feedback signals of the temperature controller, and the temperature controller outputs pulse width modulation signals according to the feedback signals to control the switch driving circuit to drive the semiconductor refrigerator to refrigerate the quartz wafer, so that the active temperature control of the quartz wafer is realized; and finally, establishing a double closed-loop tracking control model of circuit output signals and temperature by taking the resonant circuit system as an inner loop and the dew point temperature tracking system as an outer loop.
2. The dual closed loop dew point tracking control method for a quartz resonant dew point sensor as set forth in claim 1, wherein: the control method is realized based on an automatic test control system of a quartz resonance type dew point sensor, and when the system is operated for the first time, if the logic level of the oscillation state of the corresponding resonance circuit is high, the amplitude of the quartz wafer at the moment is recorded as the initial amplitude; during the first temperature reduction, the measurement system takes the amplitude of the quartz wafer as the basis to ensure that the temperature reduction rate is a fixed value when the temperature approaches the dew point; meanwhile, the measurement system records the amplitude data of the quartz wafer every other one second in the cooling process until the quartz wafer stops vibrating, and the median of the amplitude data within 10 seconds before the quartz wafer stops vibrating is taken as the critical amplitude of the vibration stopping; after the initial amplitude and the oscillation stopping critical amplitude are obtained, the system starts formal measurement; firstly, if the logic level is high, the quartz wafer is not condensed, whether the amplitude of the quartz wafer is close to the initial amplitude or not needs to be judged, if the difference between the amplitude of the quartz wafer and the initial amplitude is 0.1V, the difference between the current temperature and the dew point temperature is large, and then the temperature is rapidly reduced; otherwise, judging whether the amplitude of the quartz wafer is close to the oscillation stopping critical amplitude, if the difference between the amplitude of the quartz wafer and the oscillation stopping critical amplitude is 0.1V, cooling at an extremely slow speed; if the amplitude of the quartz wafer is between the initial amplitude and the oscillation stopping critical amplitude, slowly reducing the temperature; if the logic level is low, the resonance circuit stops vibrating and the temperature is increased at a slow speed; when the low level duration time exceeds 10 seconds, the difference between the current temperature and the dew point temperature is considered to be large, and the temperature is increased at a high speed; and when the logic level is rapidly turned over in unit time, the dew point temperature is considered to be reached at the moment, and the temperature average value in the turning time is taken as the dew point temperature value to be output.
3. The dual closed loop dew point tracking control method for a quartz resonant dew point sensor as set forth in claim 2, wherein: the initial amplitude is the amplitude of a sinusoidal signal output by the sensitive driving circuit under the natural state of the quartz wafer.
4. The dual closed loop dew point tracking control method for a quartz resonant dew point sensor as set forth in claim 2, wherein: the oscillation stop critical amplitude is an amplitude of the quartz wafer at the time of oscillation stop due to dew condensation.
5. The dual closed loop dew point tracking control method for a quartz resonant dew point sensor as claimed in claim 2 or 3 or 4, wherein: the invention discloses an automatic test control system of a quartz resonance type dew point sensor, which is an automatic test control system consisting of a sensor detection module, a sensitive circuit module, a processor module, a temperature measurement module and a temperature control module and is used for providing a hardware function carrier for realizing the control method of the invention.
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1632546A (en) * | 2004-12-24 | 2005-06-29 | 王世光 | Monolithic piezoelectric and ferroelectric crystal multifunctional dew point humidity sensor |
| CN201233364Y (en) * | 2008-06-13 | 2009-05-06 | 淄博惠杰电气技术开发有限公司 | Dew point instrument based on NDIR |
| CN102520015A (en) * | 2011-12-12 | 2012-06-27 | 北京航空航天大学 | Sensitive circuit type dew point measuring method |
| CN104458809A (en) * | 2014-12-01 | 2015-03-25 | 郑州轻工业学院 | Quartz resonance sensitive circuit for recognizing dew point |
| CN105424750A (en) * | 2015-10-30 | 2016-03-23 | 长春气象仪器研究所 | Dew point transducer based on surface acoustic wave sensing element |
| CN106885826A (en) * | 2017-03-31 | 2017-06-23 | 北京航空航天大学 | A kind of Automatic Checkout ＆ Control System for quartz resonance dew point transducer |
-
2021
- 2021-06-10 CN CN202110648011.0A patent/CN113391660B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1632546A (en) * | 2004-12-24 | 2005-06-29 | 王世光 | Monolithic piezoelectric and ferroelectric crystal multifunctional dew point humidity sensor |
| CN201233364Y (en) * | 2008-06-13 | 2009-05-06 | 淄博惠杰电气技术开发有限公司 | Dew point instrument based on NDIR |
| CN102520015A (en) * | 2011-12-12 | 2012-06-27 | 北京航空航天大学 | Sensitive circuit type dew point measuring method |
| CN104458809A (en) * | 2014-12-01 | 2015-03-25 | 郑州轻工业学院 | Quartz resonance sensitive circuit for recognizing dew point |
| CN105424750A (en) * | 2015-10-30 | 2016-03-23 | 长春气象仪器研究所 | Dew point transducer based on surface acoustic wave sensing element |
| CN106885826A (en) * | 2017-03-31 | 2017-06-23 | 北京航空航天大学 | A kind of Automatic Checkout ＆ Control System for quartz resonance dew point transducer |
Non-Patent Citations (1)
| Title |
|---|
| 罗轶轲等: "基于石英敏感电路的露点跟踪测量系统", 《仪表技术与传感器》 * |
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