CN112564705A - Multi-channel data acquisition method for radon measuring instrument - Google Patents

Multi-channel data acquisition method for radon measuring instrument Download PDF

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CN112564705A
CN112564705A CN202011386041.0A CN202011386041A CN112564705A CN 112564705 A CN112564705 A CN 112564705A CN 202011386041 A CN202011386041 A CN 202011386041A CN 112564705 A CN112564705 A CN 112564705A
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mcu
limit voltage
sampling
data
moment
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CN112564705B (en
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魏烈祥
张晶
汪天照
王庭宇
张威
邓世华
廖辉
秦鸣东
文富春
贾伟强
皮春辉
阳琴
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Hubei Fangyuan Environmental Protection Science & Technology Co ltd
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Hubei Fangyuan Environmental Protection Science & Technology Co ltd
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    • HELECTRICITY
    • H03ELECTRONIC CIRCUITRY
    • H03MCODING; DECODING; CODE CONVERSION IN GENERAL
    • H03M1/00Analogue/digital conversion; Digital/analogue conversion
    • H03M1/12Analogue/digital converters
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01TMEASUREMENT OF NUCLEAR OR X-RADIATION
    • G01T1/00Measuring X-radiation, gamma radiation, corpuscular radiation, or cosmic radiation
    • G01T1/16Measuring radiation intensity
    • G01T1/17Circuit arrangements not adapted to a particular type of detector
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01TMEASUREMENT OF NUCLEAR OR X-RADIATION
    • G01T1/00Measuring X-radiation, gamma radiation, corpuscular radiation, or cosmic radiation
    • G01T1/29Measurement performed on radiation beams, e.g. position or section of the beam; Measurement of spatial distribution of radiation
    • GPHYSICS
    • G05CONTROLLING; REGULATING
    • G05BCONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
    • G05B19/00Programme-control systems
    • G05B19/02Programme-control systems electric
    • G05B19/04Programme control other than numerical control, i.e. in sequence controllers or logic controllers
    • G05B19/042Programme control other than numerical control, i.e. in sequence controllers or logic controllers using digital processors
    • G05B19/0423Input/output
    • GPHYSICS
    • G05CONTROLLING; REGULATING
    • G05BCONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
    • G05B2219/00Program-control systems
    • G05B2219/20Pc systems
    • G05B2219/24Pc safety
    • G05B2219/24215Scada supervisory control and data acquisition

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  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • High Energy & Nuclear Physics (AREA)
  • Molecular Biology (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Theoretical Computer Science (AREA)
  • Automation & Control Theory (AREA)
  • Measurement Of Radiation (AREA)
  • Nuclear Medicine (AREA)

Abstract

The invention provides a multi-channel data acquisition method for a radon meter, which conditions the output signal of a detector of the radon meter to obtain a conditioned output signal V1The analog watchdog monitoring of MCU is utilized, and the ADC controller of MCU adopts multiple ADC modes to output signal V1Sampling, storing in an annular storage queue in a DMA mode, triggering and recording the rising edge and the falling edge of an alpha particle peak by simulating a watchdog, and taking out corresponding position data in the annular storage queue as all peak shape data to realize real-time detection. The radon measuring instrument multi-channel data acquisition method provided by the invention realizes simultaneous sampling storage of multiple acquisition ends by using a DMA (direct memory access) annular storage technology, and triggers MCU (microprogrammed control unit) sampling by using MCU simulation watchdog, thereby greatly improvingThe sampling efficiency is improved, the operation is convenient, and the cost is reduced.

Description

Multi-channel data acquisition method for radon measuring instrument
Technical Field
The invention relates to a multi-channel data acquisition method for a radon measuring instrument, and belongs to the technical field of signal sampling.
Background
Referring to fig. 2, the conventional radon measuring instrument signal sampling process is as follows: an Input alpha particle detector signal is subjected to preamplification circuit, shaping circuit and amplification processing, the amplified signal is Input to an ADC (analog to digital converter) port of an MCU (micro controller Unit), and a signal Output by a comparator is Output to an I/O (Input/Output) port of the MCU. When the alpha particles form an electric pulse signal on the detector, the electric pulse signal is conditioned, a jump signal is output from the comparator to trigger the I/O interruption of the MCU, the MCU starts the single-path ADC to work, the signal is sampled, and the peak searching is carried out to calculate the energy of the alpha particles.
The traditional radon measuring instrument signal sampling mode has the following defects:
firstly, an output jump signal of a comparator triggers an MCU to start analog-to-digital conversion, the MCU has time delay from triggering to data sampling, peak sampling is easy to miss, and sampling accuracy and efficiency are reduced;
secondly, because the sampling rate of the single-channel ADC is not high, the width of the signal which is widened is large in order to collect the wave crest, so that the dead time is large, and when the activity of alpha particles is large, the detection efficiency of the alpha particles can be reduced;
and thirdly, an additional comparator circuit is needed, and the threshold value of the comparator needs to be set by a D/A or a potentiometer, so that the noise source of the signal is increased.
Disclosure of Invention
In order to solve the defects of the prior art, the invention provides a multi-channel data acquisition method of a radon measuring instrument, which utilizes triple ADC (analog to digital converter) and DMA (Direct memory access) technologies to sample signal data in real time and store the signal data in an annular storage queue, simultaneously simulates a watchdog to monitor the signal in real time, and when a set threshold value is reached, a MCU (micro control unit) is triggered to read corresponding peak data in the annular storage queue, and the energy of alpha particles is searched and calculated.
The technical scheme adopted by the invention for solving the technical problem is as follows: the utility model provides a radon measuring instrument multichannel data acquisition method, which comprises the following steps:
(1) conditioning the output signal of the detector of the emanometer to obtain conditioned output signal V1
(2) Analog watchdog using MCU larger than upper limit voltage VHOr less than the lower limit voltage VLI.e. interrupt-generating characteristic monitoring of the output signal V of the ADC controller access1Setting its upper limit voltage VHAnd a lower limit voltage VL
(3) The ADC controller of the MCU adopts a double or triple ADC mode to output a signal V1Sampling, storing the sampled data in an annular storage queue in a DMA mode, and waiting for MCU processing;
(4) upper limit voltage VHSet as the threshold value to be detected by the analog watchdog, namely the rising edge threshold value of the alpha particle peak, and set the lower limit voltage VLSet to 0 when the sampled data is greater than the upper limit voltage VHWhen the watch dog is simulated, the MCU is triggered by the watch dog and the current first moment t is recorded1And is currentlyThe data location of the circular storage queue that is being sampled and stored at this time is denoted as the first data sample location Addr1, the first time t1Namely the moment of the rising edge of the alpha particle peak;
(5) lower limit voltage VLIs set as a threshold value to be detected by the analog watchdog, namely a falling edge threshold value of an alpha particle peak, and an upper limit voltage VHSetting the value as the full scale value of ADC sampling when the sampled data is less than the lower limit voltage VLWhen the watch dog is simulated, the MCU is triggered by the watch dog and the current second moment t is recorded2And the data position of the current annular storage queue which is sampled and stored at the moment is recorded as a second data sampling position Addr2 and a second moment t2Namely the moment of the falling edge of the alpha particle peak;
(6) determining the time delay from the monitoring of the rising edge by the analog watchdog to the data sampling position Addr1 of the recording annular storage queue, converting the time delay into the storage interval n of the annular storage queue, taking the starting point of peak searching calculation as the storage position Addr1-n of the annular storage queue, and taking the data between the storage position Addr1-n of the annular storage queue and the storage position Addr2 as the total peak shape data of the current alpha particle peak;
(7) and (5) repeating the steps (4) to (6) to sample each section of alpha particle peak, so as to realize the real-time detection of the alpha particle energy by the radon detector.
The output signal V of the step (1)1The pre-conditioning is obtained by the following processes:
(a) using a pre-amplifier circuit to amplify the initial input signal ViPre-amplifying to output pre-amplified signal Va
(b) Pre-amplified signal VaOutput signal V via signal conditioning circuit1
The MCU adopts an STM32F407 chip.
The invention has the beneficial effects based on the technical scheme that:
(1) according to the multi-channel data acquisition method of the emanometer, the internal simulation watchdog of the MCU replaces an external comparison circuit, the circuit is simple, the noise is reduced, the cost is saved, the upper limit value and the lower limit value of the simulation watchdog can be set through conventional setting software, and the operation is convenient;
(2) the multi-channel data acquisition method of the emanometer provided by the invention adopts multiple ADC assembly line sampling, the maximum sampling rate can reach N times of single-channel sampling, N is the number of the ADC controllers of the MCU, and the sampling rate is improved, so that the widening time of a shaping widening circuit in a signal conditioning circuit can be shortened, the sampling dead time is reduced, and the alpha particle acquisition efficiency is improved;
(3) the multi-channel data acquisition method of the emanometer provided by the invention adopts the DMA annular storage queue, samples and stores in real time, and can sample data in real time without being influenced by other tasks of the MCU.
(4) According to the multi-channel data acquisition method for the radon meter, provided by the invention, the rising edge of an input signal is monitored by simulating a watchdog, and the full peak of alpha particles is acquired by compensating data of n periods of forward movement, so that the wave crest of the alpha particles can be accurately acquired, and the energy peak of the alpha particles can be correctly calculated.
Drawings
FIG. 1 is a schematic diagram of a sampling circuit adopted by the multi-channel data acquisition method of the radon meter provided by the invention.
Fig. 2 is a schematic diagram of a conventional signal sampling circuit.
Detailed Description
The invention is further illustrated by the following figures and examples.
The invention provides a multi-channel data acquisition method of a radon measuring instrument, which comprises the following steps with reference to fig. 1:
(1) conditioning the output signal of the detector of the emanometer to obtain conditioned output signal V1
(2) Analog watchdog using MCU larger than upper limit voltage VHOr less than the lower limit voltage VLOutput signal V for monitoring ADC channel access by characteristic of generating interrupt1Setting its upper limit voltage VHAnd a lower limit voltage VL
(3) The ADC controller of the MCU adopts a double or triple ADC mode to output a signal V1Sampling, storing the sampled data in an annular storage queue in a DMA modeIn the column, waiting for MCU processing; in this embodiment, triple ADC sampling is adopted, namely ADC1, ADC2 and ADC 3;
(4) upper limit voltage VHSet as the threshold value to be detected by the analog watchdog, namely the rising edge threshold value of the alpha particle peak, and set the lower limit voltage VLSet to 0 when the sampled data is greater than the upper limit voltage VHWhen the watch dog is simulated, the MCU is triggered by the watch dog and the current first moment t is recorded1And the data position of the current annular storage queue which is sampled and stored at the moment is recorded as a first data sampling position Addr1, and the first moment t1Namely the moment of the rising edge of the alpha particle peak;
(5) lower limit voltage VLIs set as a threshold value to be detected by the analog watchdog, namely a falling edge threshold value of an alpha particle peak, and an upper limit voltage VHSetting the value as the full scale value of ADC sampling when the sampled data is less than the lower limit voltage VLWhen the watch dog is simulated, the MCU is triggered by the watch dog and the current second moment t is recorded2And the data position of the current annular storage queue which is sampled and stored at the moment is recorded as a second data sampling position Addr2 and a second moment t2Namely the moment of the falling edge of the alpha particle peak;
(6) determining the time delay from the monitoring of the rising edge by the analog watchdog to the data sampling position Addr1 of the recording annular storage queue, converting the time delay into the storage interval n of the annular storage queue, taking the starting point of peak searching calculation as the storage position Addr1-n of the annular storage queue, and taking the data between the storage position Addr1-n of the annular storage queue and the storage position Addr2 as the total peak shape data of the current alpha particle peak;
(7) and (5) repeating the steps (4) to (6) to sample each section of alpha particle peak, so as to realize the real-time detection of the alpha particle energy by the radon detector.
The output signal V of the step (1)1The pre-conditioning is obtained by the following processes:
(a) using a pre-amplifier circuit to amplify the initial input signal ViPre-amplifying to output pre-amplified signal Va
(b) Pre-amplified signal VaOutput via a signal conditioning circuitSignal V1
The MCU adopts an STM32F407 chip.
According to the multi-channel data acquisition method for the emanometer, provided by the invention, simultaneous sampling storage of multiple acquisition ends is realized by using a DMA (direct memory access) annular storage technology, and MCU sampling is triggered by using the MCU to simulate a watchdog, so that the sampling efficiency is greatly improved, the operation is convenient, and the cost is reduced.

Claims (3)

1. A multi-channel data acquisition method for a radon measuring instrument is characterized by comprising the following steps:
(1) conditioning the output signal of the detector of the emanometer to obtain conditioned output signal V1
(2) Analog watchdog using MCU larger than upper limit voltage VHOr less than the lower limit voltage VLI.e. interrupt-generating characteristic monitoring of the output signal V of the ADC controller access1Setting its upper limit voltage VHAnd a lower limit voltage VL
(3) The ADC controller of the MCU adopts a double or triple ADC mode to output a signal V1Sampling, storing the sampled data in an annular storage queue in a DMA mode, and waiting for MCU processing;
(4) upper limit voltage VHSet as the threshold value to be detected by the analog watchdog, namely the rising edge threshold value of the alpha particle peak, and set the lower limit voltage VLSet to 0 when the sampled data is greater than the upper limit voltage VHWhen the watch dog is simulated, the MCU is triggered by the watch dog and the current first moment t is recorded1And the data position of the current annular storage queue which is sampled and stored at the moment is recorded as a first data sampling position Addr1, and the first moment t1Namely the moment of the rising edge of the alpha particle peak;
(5) lower limit voltage VLIs set as a threshold value to be detected by the analog watchdog, namely a falling edge threshold value of an alpha particle peak, and an upper limit voltage VHSetting the value as the full scale value of ADC sampling when the sampled data is less than the lower limit voltage VLWhen the watch dog is simulated, the MCU is triggered by the watch dog and the current second moment t is recorded2And the data position of the current annular storage queue which is sampled and stored at the moment is recorded as the secondData sample location Addr2, second time t2Namely the moment of the falling edge of the alpha particle peak;
(6) determining the time delay from the monitoring of the rising edge by the analog watchdog to the data sampling position Addr1 of the recording annular storage queue, converting the time delay into the storage interval n of the annular storage queue, taking the starting point of peak searching calculation as the storage position Addr1-n of the annular storage queue, and taking the data between the storage position Addr1-n of the annular storage queue and the storage position Addr2 as the total peak shape data of the current alpha particle peak;
(7) and (5) repeating the steps (4) to (6) to sample each section of alpha particle peak, so as to realize the real-time detection of the alpha particle energy by the radon detector.
2. The multi-channel data acquisition method for the emanometer according to claim 1, wherein: the output signal V of the step (1)1The pre-conditioning is obtained by the following processes:
(a) using a pre-amplifier circuit to amplify the initial input signal ViPre-amplifying to output pre-amplified signal Va
(b) Pre-amplified signal VaOutput signal V via signal conditioning circuit1
3. The multi-channel data acquisition method for the emanometer according to claim 1, wherein: the MCU adopts an STM32F407 chip.
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