CN214845733U - Remote calibration system for voltage source - Google Patents
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- CN214845733U CN214845733U CN202121052817.5U CN202121052817U CN214845733U CN 214845733 U CN214845733 U CN 214845733U CN 202121052817 U CN202121052817 U CN 202121052817U CN 214845733 U CN214845733 U CN 214845733U
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Abstract
The utility model provides a long-range calibration system of voltage source. The voltage source remote calibration system comprises an on-site control computer and a remote control computer; the field control computer is connected with the to-be-detected meter and the first time interval counter; the meter to be checked is a direct current voltage source; the to-be-detected meter is connected with a first time interval counter through a first voltage frequency conversion module, and the first time interval counter is also connected with a first GPS common-view receiver; the remote control computer is connected with the standard device and the second time interval counter; the etalon is connected with a second time interval counter through a second voltage frequency conversion module, and the second time interval counter is also connected with a second GPS common-view receiver; and data transmission is carried out between the field control computer and the remote control computer through a DataSocket communication technology. Compare in traditional calibration mode, the utility model discloses a long-range calibration system by a wide margin has shortened calibration time, has reduced the cost of labor, has improved calibration efficiency.
Description
Technical Field
The utility model belongs to the technical field of electricity measurement calibration and specifically relates to a long-range calibration system of voltage source.
Background
The measurement is the activity of realizing unity, guaranteeing the accurate and reliable magnitude, and is related to the national civilization. The quantity value transmission and tracing of the measuring instrument are realized by metrological verification and calibration, and from the technical point of view, the verification and the calibration are both comparative methods. The measurement standard and the test instrument are compared in a predetermined measurement environment. The off-line method is mostly needed, during verification or calibration, the working metering device is detached and sent to a corresponding technical mechanism, and a static or steady-state test process is carried out under a specified experimental environment. In addition, this approach only yields the basic error of the metrology instrument, while the additional error of the instrument in field applications is not known. Any measurement has an error during the metrology test, and the measurement error can be divided into two parts, one part being the basic error and the other part being the additive error. The basic error of an instrument refers to the maximum error of the instrument under a specified reference working condition (verification or calibration laboratory), and generally the basic error is the allowable error of the instrument. Additional error refers to additional error that may be introduced when the instrument is used under non-specified reference operating conditions (non-verification or calibration laboratories), such as measurement error that may be introduced by the instrument in an industrial field environment, and the like. One can obtain the basic error of the instrument by rigorous metrological verification or calibration under prescribed measurement conditions. However, additional errors due to the variety and variability of field operating conditions are currently unavailable.
The development of the internet of things technology enables the measurement of the additional error to be possible, if a remote quantity value transmission and traceability system of the measuring instrument can be established by using the internet of things technology, the additional error of the instrument can be obtained, the accuracy and the reliability of the measuring data are fundamentally ensured, and the product quality is fundamentally improved.
The direct current voltage is the most basic parameter in the electromagnetic metrology, and provides a traceability basis for the electromagnetic metrology and other metrology fields. The dc standard voltage source is generally widely used in various metering mechanisms as a standard device for storing and reproducing the magnitude of the dc voltage due to its high accuracy and wide measurement range. The traditional manual calibration has low efficiency, many cautions and complicated operation process, and the technical level and the working experience of the calibration personnel have great influence on the measurement result. Therefore, it is necessary to introduce a remote automatic calibration procedure to ensure the mass transfer quality and improve the mass transfer efficiency.
SUMMERY OF THE UTILITY MODEL
The utility model aims at providing a long-range calibration system of voltage source aims at realizing the long-range calibration of the most genuine direct current voltage source, changes its flow of tracing to the source, improves its calibration efficiency.
The utility model discloses a realize like this: a voltage source remote calibration system comprises a field control computer and a remote control computer; the field control computer is respectively connected with the to-be-detected meter and the first time interval counter through a standard interface, and is used for sending a program control instruction to the to-be-detected meter so as to enable the to-be-detected meter to output a voltage signal, and meanwhile, the field control computer is also used for receiving the signal sent by the first time interval counter; the meter to be detected is a direct current voltage source; the table to be detected is connected with the first time interval counter through a first voltage frequency conversion module, and the first time interval counter is also connected with a first GPS common-view receiver; the first voltage frequency conversion module is used for converting a voltage signal output by the meter to be detected into a first pulse string and sending the first pulse string to a first time interval counter, and the first time interval counter counts the first pulse string to obtain a first frequency signal and sends the first frequency signal to the field control computer; the first GPS common-view receiver measures a field frequency source and a GPS signal transmitted by a GPS satellite and sends the measured signal to a field control computer through a first time interval counter; the remote control computer is respectively connected with the standard device and the second time interval counter through a standard interface, and is used for sending a program control instruction to the standard device to enable the standard device to output a voltage signal, and meanwhile, the remote control computer is also used for receiving the signal sent by the second time interval counter; the etalon is connected with the second time interval counter through a second voltage frequency conversion module, and the second time interval counter is also connected with a second GPS common-view receiver; the second voltage frequency conversion module is used for converting the voltage signal output by the standard device into a second pulse string and sending the second pulse string to a second time interval counter, and the second time interval counter counts the second pulse string to obtain a second frequency signal and sends the second frequency signal to the remote control computer; the second GPS common-view receiver measures a far-end frequency source and a GPS signal transmitted by a GPS satellite and sends the measured GPS signal to the far-end control computer through a second time interval counter; and the field control computer and the remote control computer carry out data transmission by a DataSocket communication technology, and the remote control computer processes data based on a GPS common vision method to realize automatic calibration of errors and uncertainty of the table to be detected.
Preferably, the first voltage frequency conversion module and the second voltage frequency conversion module each include an LM331 chip and a peripheral circuit. The peripheral circuit mainly comprises voltage frequency conversion switching switches P1 and P3, two SMA interfaces P2 and P4, a power supply P5, low-pass filter circuits C4 and R7, pull-up resistors R5 and R9, a resistor R6 and a slide rheostat R8 for adjusting the voltage frequency conversion ratio, five filter capacitors C2, C3, C5, C6 and C7, an LED indicator light D1 and the like.
Preferably, the standard is a 5522A multi-product calibrator.
Preferably, the first time interval counter and the second time interval counter are both SYN563 type high precision general purpose counters.
Preferably, the first GPS co-view receiver and the second GPS co-view receiver are both SYN4102 GPS synchronous clocks.
The field control computer and the remote control computer are respectively provided with a configuration information management module, a calibration control module, a measurement state display module and a data processing and report generating module. The configuration information management module is used for completing resource calling, task allocation and man-machine interaction of the system and realizing functions of all information configuration, environment parameter configuration, a standard device, information to be checked, report storage path selection and the like in the certificate report. The calibration control module comprises a calibration flow control part and a calibration data storage part, and the core is the calibration flow control; and carrying out the whole calibration process according to the programmed flow chart of the voltage source remote calibration system, and storing the data to the specified position. The measurement state display module is mainly used for displaying various schedules and data in the measurement process in real time, and comprises measurement schedule display, measurement data display and single-point retest display. The data processing and report generating module mainly completes the functions of data processing, error and uncertainty evaluation and report generation of calibration.
The utility model provides a voltage source remote calibration method, including following step:
a. initializing a standard device and a table to be checked; the meter to be detected is a direct current voltage source;
b. setting verification parameters;
c. and (3) starting calibration: respectively sending program control instructions to the to-be-detected meter and the standard device through the field control computer and the remote control computer to enable the to-be-detected meter and the standard device to respectively output voltage signals;
d. the first voltage frequency conversion module converts a voltage signal output by the meter to be detected into a first pulse string; the second voltage frequency conversion module converts the voltage signal output by the standard device into a second pulse string;
e. the first time interval counter counts the first pulse train to obtain a first frequency signal and sends the first frequency signal to the field control computer; the second time interval counter counts the second pulse train to obtain a second frequency signal and sends the second frequency signal to the remote control computer;
f. the first GPS common-view receiver measures a field frequency source and a GPS signal and sends the field frequency source and the GPS signal to a field control computer through a first time interval counter; the second GPS common-view receiver measures a far-end frequency source and a GPS signal and sends the far-end frequency source and the GPS signal to the far-end control computer through a second time interval counter;
g. data transmission is carried out between the field control computer and the remote control computer through a DataSocket communication technology, and the remote control computer processes data based on a GPS common-view method to realize calibration of a table to be checked.
Present situation and the domestic and overseas present situation of voltage source calibration based on remote calibration research, to the not enough in the aspect of present voltage source calibration, the utility model discloses a voltage source remote calibration system and calibration method have been developed. The utility model discloses develop one set of voltage source remote calibration system who is applicable to modern measurement requirement based on voltage frequency conversion module, GPS common vision and data socket network communication technique and video monitoring technique, realize the long-range automatic calibration of voltage source.
The utility model discloses carried out error and uncertainty analysis to the calbiration system, compared with current national measurement technical specification JJF1638-2017 "multi-functional standard source calibration standard", reached the volume and passed the index requirement. Compare in traditional calibration mode, the utility model discloses a long-range calibration system by a wide margin has shortened calibration time, has reduced the cost of labor, has improved calibration efficiency etc..
Drawings
Fig. 1 is a schematic diagram of a hardware structure in the system of the present invention.
Fig. 2 is a specific circuit diagram of the medium voltage frequency conversion module of the present invention.
Fig. 3 is a schematic diagram of the software structure in the system of the present invention.
Fig. 4 is a schematic flow chart of the calibration method of the present invention.
Detailed Description
The utility model provides a long-range calibration system of voltage source and calibration method are based on the long-range quantity transmission of thing networking and the realization of technology of tracing to the source. The utility model discloses a voltage frequency conversion module of design high accuracy utilizes this module to convert standard voltage source and the voltage magnitude of waiting to examine voltage source output into corresponding frequency signal respectively, and then based on GPS looks method and relevant algorithm altogether, accomplishes the design of the long-range calibration system of voltage source, realizes the long-range calibration of the voltage source in the true sense, improves calibration efficiency.
The system of the utility model consists of a hardware part and a software part. The utility model discloses with each hardware through standard interface connection to computer, the system adopts LabVIEW software and relevant instrument drive to compile automatic calibration procedure and software to call the frame.
As shown in fig. 1, the hardware in the system of the present invention mainly comprises a table to be checked (corresponding to the dc voltage source in fig. 1), a standard (i.e. a standard voltage source), two voltage-frequency conversion modules (VFC conversion modules), two time interval counters and two GPS co-view receivers. The field control computer is respectively connected with the direct current voltage source and the first time interval counter through a standard interface, and the far-end control computer is respectively connected with the standard device and the second time interval counter through the standard interface. The first voltage frequency conversion module is respectively connected with the direct-current voltage source and a first time interval counter, and the first time interval counter is connected with a first GPS common-view receiver. And the second voltage frequency conversion module is respectively connected with the standard device and a second time interval counter, and the second time interval counter is connected with a second GPS common-view receiver. The voltage source, the VFC conversion module, the GPS common-view receiver and the time interval counter are mutually connected through the wiring equipment.
The utility model discloses well etalon chooses the super many products calibrator of 5522A that American FLUKE company produced for use. The 5522A super multi-product calibrator of the U.S. FLUKE company is a high-precision calibration source and can provide accurate alternating-current and direct-current voltage, alternating-current and direct-current, frequency and the like. It can maintain stable performance index in wide environment temperature range. The standard device is provided with a standard interface, has complete program control capability, can receive commands and parameters of a control computer, and provides specified electrical parameter output data according to the commands and parameters.
The two voltage frequency conversion modules adopt LM331 modules. LM331 is a relatively high cost integrated chip that can be used as a precision frequency-to-voltage converter, an A/D converter, a linear frequency modem, a long-term integrator, and other related devices. LM331 adopts a new temperature compensation energy gap reference circuit, which has extremely high precision in the whole working temperature range and under the power voltage as low as 4.0V. The dynamic range of LM331 is wide, can reach 100 dB; the linearity is good, the maximum nonlinear distortion is less than 0.01%, and the working frequency is as low as 0.1Hz, so that the linearity is good; the transformation precision is high, and the digital resolution can reach 12 bits; the external circuit is simple, and can conveniently form a V/F (voltage/frequency) or F/V (frequency/voltage) conversion circuit only by connecting a plurality of external elements, and the conversion precision is easy to ensure.
The principle of the voltage-frequency conversion module is as follows: monolithically integrated V/F converters are widely used in automatic control, digital instrumentation and radio equipment to perform voltage and frequency conversion. The anti-interference capability of the frequency conversion circuit is enhanced after the voltage is converted into the frequency signal, and the application is very convenient. In the actual signal conversion process, the main conversion modes include a multi-resonant mode and a charge balance mode. Because charge balance formula VFC equipment has higher degree of accuracy than other equipment, the utility model discloses select charge balance formula voltage frequency conversion module. The basic principle is as follows: with a capacitor as charge carrier, input voltage VINGenerating a current I proportional theretoINCharging the capacitor while using a known constant current source IREF(wherein I)REF>IINmax) The capacitor is periodically and reversely charged, and the charging time is fixed to Tc each time, so that the input and output charge balance of the capacitor in each period or a plurality of periods is realized. At the same time, this period is also the period of the output signal, the frequency or average frequency of the output signal and the input voltage VINIs in direct proportion. The voltage-frequency converter actually just converts the voltage into a pulse train, and the final frequency value needs to be obtained by counting and calculating the pulses through a counter.
As shown in fig. 2, the voltage-frequency conversion module uses an LM331 chip as a core, and a peripheral circuit is disposed outside the LM331 chip. In the LM331 chip, pin 1 is the current output, pin 2 is the reference current, pin 3 is the frequency output, pin 4 is the ground, pin 5 is the R-C filter input, pin 6 is the threshold input, pin 7 is the comparator input, and pin 8 is the supply voltage. The main peripheral circuits are: p1 and P3 are voltage-frequency conversion switches, when the switches are used for converting voltage into frequency, P1 is switched to 7 pins to be used as input, and P3 is switched to 3 pins to be used as output; when the frequency conversion voltage is used, the P3 is switched to the pin 6 to be used as input, and the P1 is switched to the pin 1 to be used as output. P2 and P4 are two SMA interfaces; p5 is power supply; r5 and R9 are pull-up resistors; r6 and slide rheostat R8 are used for adjusting the voltage frequency conversion ratio; c2, C3 and C5 are filter capacitors; c6 and C7 are filter capacitors; c4 and R7 are low-pass filter circuits; d1 is an LED indicator light.
The two time interval counters are SYN5636 type high-precision universal counters of Simian synchronous electronic technology, Inc. This is a time interval and frequency test instrument. The frequency measurement resolution can reach 12 bits/s and 15 bits/1000 s, the measured frequency range is up to 24GHz, the time interval resolution is up to 20ps, the power meter function is realized, and the time base is matched with the high-precision OCXO constant-temperature crystal oscillator. The counter has the functions of measuring frequency, period, frequency ratio, input power maximum value, time interval, pulse width, rising/falling time and the like, and has strong mathematical operation and statistical functions including average value, standard deviation, maximum value, peak-to-peak value, accumulated count, alendron variance, frequency deviation and the like. The counter has the advantages of reliable performance, high measurement precision, wide range, high sensitivity, large dynamic range and high cost performance.
The two GPS co-vision receivers adopt SYN4102 type GPS synchronous clock of Simian synchronous electronic technology and Co. The clock frequency source is a high-precision phase-locked clock frequency source, receives GPS signals, enables the output frequency of the constant-temperature crystal oscillator to be synchronous with the cesium atomic clock signals of a GPS satellite, improves the long-term stability and accuracy of the frequency signals, can provide a high-precision time frequency standard of a cesium clock magnitude, and is a high-cost-performance time frequency product.
GPS common view principle: GPS co-view time frequency transfer is one of the major methods for time frequency long-distance magnitude transfer at present. The basic principle of the common view technology is that atomic clocks in any two places on the earth within the view angle of one GPS satellite can perform time frequency comparison by using time signals of the same satellite received at the same time. A. And B, the receivers in the two places receive the same GPS satellite signal at the same time under the action of the same common view time schedule. The built-in time interval counter measures the time difference delta t between GPS second pulse and local atomic clock second pulseAGPS、ΔtBGPS. The data of the B place is transmitted to the A place through a communication network, and then the time difference between the two atomic clocks can be obtained through subtraction. Setting the clock times of the points A and B as tAAnd tBGPS time is tGPS，ΔtAGPS＝tA-tGPS；ΔtBGPS＝tB-tGPS；ΔtAGPS-ΔtBGPS＝tA-tB＝ΔtAB(ii) a After a plurality of measurements, a series of delta t can be obtainedABiFrom this, the average relative frequency difference of two atomic clocks in a period of time can be calculated
In the formula fA、fBThe frequencies of the two clocks are respectively; τ is the average time interval.
Fig. 3 is a software module structure diagram of the system of the present invention. The software part adopts the design idea of modular software to divide the calibration software installed on a remote upper computer into a plurality of functional modules according to functions, and the system adopts LabVIEW software and related instrument drivers to program an automatic calibration program and a software calling framework. The program development is carried out aiming at the remote calibration of the voltage source, the core of the system software is the control of a calibration flow and the processing of calibration data, the system software controls the setting of each calibration parameter, the standard device sends a standard signal, the to-be-detected meter sends a to-be-detected signal, and then the software acquires the counter signal to replace the prior manual operation, eye observation and hand writing recording processes. Meanwhile, the range, the calibration point, the calibration value, the uncertainty, the allowable error and the actual error of each point of the calibrated direct-current voltage source are monitored in real time in the calibration process, and the single-point retest can be carried out on the unqualified points. After the test is finished, the calibration data is stored in a database, on the basis, software carries out data analysis and processing by using a reasonable algorithm to obtain the voltage source error and uncertainty, and automatic calibration is finished.
Specifically, the utility model discloses software part comprises four big modules in the system, including configuration information management module, calibration control module, measurement state display module and data processing and report generation module. The main functions of each module are as follows: (1) a configuration information management module: the module mainly completes resource calling, task allocation and man-machine interaction of the system, and realizes functions of all information configuration, environment parameter configuration, standards and calibrated instrument information in the certificate report, report storage path selection and the like. (2) A calibration control module: the module comprises two parts of calibration flow control and calibration data storage, and the core is the calibration flow control. And carrying out the whole calibration process according to the programmed flow chart of the voltage source remote calibration system, and storing the data to the specified position. (3) A measurement state display module: the module mainly completes real-time display of various schedules and data in the measurement process, including measurement schedule display, measurement data display and single-point retest display. (4) The data processing and report generating module: the module mainly performs the functions of data processing, error and uncertainty evaluation and report generation of calibration.
Furthermore, the utility model discloses make full use of LabVIEW is in the superiority in instrument control field. The operations of initializing the serial port, writing the serial port, reading and interrupting the serial port, closing the serial port and the like are respectively realized by using the VISA node in the LabVIEW, and the VISA node is used for programming the serial port so as to conveniently realize the communication between the application program and the interface bus instrument. Meanwhile, LabVIEW has a strong network communication function, and in a common communication method, a DataSocket network communication technology based on a TCP/IP protocol has many advantages and has many applications in the remote field in recent years. The DataSocket overcomes the defects that the traditional TCP/IP transmission protocol needs complex bottom layer programming and has slow transmission rate (particularly for dynamic data), simplifies the transmission problem of real-time data, provides an easy-to-use, high-efficiency and programmable software interface, and can conveniently realize the real-time data exchange among a plurality of computers on a network. The Datasocket realizes data communication between programs in a publishing/subscribing mode. The technology has great convenience in the aspect of real-time transmission of the measured data and high transmission speed, and is particularly suitable for acquisition and monitoring of remote data. Therefore, the utility model discloses what the system adopted is the DataSocket communication technology. The front panel controls vi in LabVIEW all have a DataSocket Connection attribute, and the DataSocket communication among the same type of controls on different computers can be realized by using the attribute. By specifying a specific URL and a connection mode, real-time data distribution (Publish) and reading (Subscribe) between a server side and a client side can be realized.
In summary, the upper computer compiles system software through LabVIEW, the system software controls the setting of each verification parameter, the standard device sends out a standard signal, the to-be-detected meter sends out a to-be-detected signal, the counter collects the signal, and the calibration software calculates the error and the uncertainty. The data socket technology of LabVIEW can be used for realizing real-time remote transmission of calibration data, and a remote laboratory after calibration judges whether the calibration requirements are met or not according to the error range and the uncertainty value.
As shown in fig. 4, fig. 4 is a flowchart of the remote calibration method of the invention. The whole calibration process is as follows: (1) initializing the standard device and the table to be checked: the system software (specifically, a configuration information management module) sends program control commands to the standard device and the table to be checked, and the standard device and the table to be checked in the system are initialized, so that the instrument is in an initialized state. (2) Setting verification parameters: and (4) selecting and setting relevant parameters such as the setting of a voltage detection point and the like according to the front panel of the calibration software. And (5) executing the step (3) under the condition that the connection of the calibration instrument is correct. (3) Outputting standard signals and signals to be measured and reading measurement data: and a calibration button is started, program control instructions are output to the standard device and the to-be-detected meter through system software (specifically a calibration control module), the standard device and the to-be-detected meter sequentially output voltage signals according to detection points set by a program, and the counter sequentially reads the voltage signals. (4) Data storage and processing: the data of the current verification project is stored in a database in real time through system software (particularly a calibration control module), the error and uncertainty values of a set point are calculated in real time according to the software (particularly a data processing and report generating module), and a corresponding report or a calibration certificate is generated. The measurement progress, the measurement data, the single-point retest and the like can be displayed in time through the measurement state display module.
Claims (6)
1. A voltage source remote calibration system is characterized by comprising a field control computer and a remote control computer; the field control computer is connected with the to-be-detected meter and the first time interval counter; the meter to be detected is a direct current voltage source; the table to be detected is connected with the first time interval counter through a first voltage frequency conversion module, and the first time interval counter is also connected with a first GPS common-view receiver; the remote control computer is connected with the standard device and the second time interval counter; the etalon is connected with the second time interval counter through a second voltage frequency conversion module, and the second time interval counter is also connected with a second GPS common-view receiver; the first voltage frequency conversion module and the second voltage frequency conversion module both comprise LM331 chips.
2. The voltage source remote calibration system of claim 1, wherein data transmission is performed between the field control computer and the remote control computer through a DataSocket communication technology.
3. A voltage source remote calibration system as claimed in claim 1 wherein said etalon is a 5522A multi-product etalon.
4. A voltage source remote calibration system according to claim 1 wherein said first time interval counter and said second time interval counter are each a SYN563 type high precision universal counter.
5. The voltage source remote calibration system of claim 1 wherein said first GPS co-view receiver and said second GPS co-view receiver are both SYN4102 GPS synchronous clocks.
6. The voltage source remote calibration system of claim 1, wherein a configuration information management module, a calibration control module, a measurement status display module, and a data processing and report generation module are provided in each of the field control computer and the remote control computer.
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| CN117040533A (en) * | 2023-08-25 | 2023-11-10 | 河北大学 | Remote self-calibration method and system for analog-to-digital conversion |
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