Insulation resistance meter calibrating device, system and method

Abstract

The invention discloses an insulation resistance meter calibrating device, system and method, the system comprises an upper computer and an insulation resistance meter calibrating device, the insulation resistance meter calibrating device comprises a box body and a small vibration table, the small vibration table is connected with the box body through a wire, and the box body is connected with the upper computer through a wire. A main control module, a resistance output module, a voltage measurement module, a temperature and humidity acquisition module, a temperature and humidity control module, a first communication module, a vibration parameter acquisition module and a vibration table control module are arranged in the box body, and a display module is arranged on a panel of the box body. The main control module is connected with the resistance output module, the voltage measurement module, the temperature and humidity acquisition module, the temperature and humidity control module, the first communication module, the vibration parameter acquisition module, the vibration table control module and the display module. The problems that in the prior art, the vibration working condition cannot be simulated, the dynamic error is not evaluated, the integration is poor, and the adaptability of high-end equipment is insufficient can be solved.

Description

Technical Field

[0001] This invention relates to an insulation resistance meter calibration device, calibration system, and calibration method, belonging to the field of high-reliability equipment metrology. Background Technology

[0002] Since the 1960s, power electronics technology has undergone leapfrog development through the rectifier era, the inverter era, and the frequency converter era, giving rise to a large number of power electronic devices with high voltage, high current, and high frequency characteristics. Their application depth and breadth in industries such as transportation have continued to expand. In the field of high-end equipment, power electronic equipment in equipment such as mobile launch platforms is subjected to complex dynamic conditions such as vibration and shock for extended periods. The insulation performance of this equipment, as a core barrier to electrical safety, directly determines the combat effectiveness and operational safety of the equipment. Insulation failure can lead to short circuits, system paralysis, and even major safety accidents. Therefore, accurate and realistic calibration of insulation resistance meters for high-end equipment is a crucial prerequisite for ensuring the reliability of equipment insulation performance.

[0003] As a core piece of metrological testing equipment, the insulation resistance meter calibration device must not only meet the testing requirements of various domestic and imported insulation resistance meters (megohmmeters) under normal conditions, but also serve as a drive device for DC standard high-resistance boxes, high-input-internal-resistance DC high-voltage meters, and grounding resistance meters. Furthermore, it must be adaptable to the special scenarios of high-end equipment industries. In the operation and maintenance of special equipment, insulation resistance meters need to operate stably under conditions such as ship navigation (10-50Hz low-frequency vibration), aircraft flight (50-500Hz medium-frequency vibration), and equipment transportation impact (100-1000Hz instantaneous vibration). Their measurement accuracy in dynamic environments directly affects the insulation performance judgment results. However, traditional calibration devices can only conduct tests in a static laboratory environment, failing to reproduce the actual vibration conditions of special equipment operation. This leads to a disconnect between calibration results and real-world usage scenarios, making it difficult to effectively identify performance defects of insulation resistance meters under vibration interference, thus posing a hidden danger to the insulation safety of special equipment.

[0004] Currently, metrology stations and equipment maintenance units at all levels of high-end equipment have an increasingly urgent need for "operating condition-based verification." There is a pressing need for an insulation resistance meter verification device that can simulate the vibration environment of high-end equipment and take into account both high precision and intelligence, in order to fill the technical gap in insulation resistance meter verification under dynamic operating conditions in the high-end equipment industry and safeguard the insulation performance of equipment.

[0005] Currently, insulation resistance meter calibration devices are mainly designed based on the specific requirements of JJG 1005-2005 "Verification Procedure for Electronic Insulation Resistance Meters" and JJG 622-1997 "Verification Procedure for Insulation Resistance Testers (Megohmmeters)". However, their application in the field of high-end equipment metrology and calibration has the following drawbacks: 1) Lack of operating condition simulation: Existing devices are all designed based on static environments and lack vibration environment simulation functions, making it impossible to reproduce low-frequency, medium-frequency vibrations and instantaneous impact conditions during the operation of special equipment; 2) Poor integration and coordination: Some units have attempted to conduct testing through a combination of "independent vibration table + traditional calibration device", but the two lack a data synchronization mechanism, and the independent vibration table is large and heavy, making it impossible to integrate with the calibration device, resulting in cumbersome operation and occupying a large amount of laboratory space; 3) Insufficient adaptability to high-end equipment: It cannot meet the requirements of standards such as GJB 151B-2013 and GJB 150A-2009 for equipment anti-interference and environmental adaptability. Summary of the Invention

[0006] In view of this, the present invention provides an insulation resistance meter calibration device, calibration system and calibration method, which can solve the problems of existing technologies that cannot simulate vibration conditions, lack dynamic error assessment, poor integration and insufficient adaptability to high-end equipment. By integrating a small vibration table, it can accurately simulate the low-frequency and medium-frequency vibration and instantaneous impact conditions of special equipment, realize the miniaturization and integration of the vibration table and calibration device, meet the space requirements of high-end equipment laboratories and on-site testing, and add image acquisition and recognition automatic test reading functions to realize automated testing.

[0007] The first objective of this invention is to provide an insulation resistance meter calibration device.

[0008] The second objective of this invention is to provide an insulation resistance meter calibration system.

[0009] The third objective of this invention is to provide a method for calibrating an insulation resistance meter.

[0010] The first objective of this invention can be achieved by adopting the following technical solution:

[0011] An insulation resistance meter calibration device includes a housing and a small vibration table. The small vibration table is connected to the housing via wires. The housing contains a main control module, a resistance output module, a voltage measurement module, a temperature and humidity acquisition module, a temperature and humidity control module, a first communication module, a vibration parameter acquisition module, and a vibration table control module. A display module is provided on the housing panel. The main control module is connected to the resistance output module, voltage measurement module, temperature and humidity acquisition module, temperature and humidity control module, first communication module, vibration parameter acquisition module, vibration table control module, and display module.

[0012] Furthermore, the resistance output module is connected to the insulation resistance meter being measured via the resistance measurement terminal, and includes nine decimal resistance disks connected in series and one fixed resistance disk. Each of the decimal resistance disks and the fixed resistance disk has a corresponding resistance rotary switch. The resistance measurement terminal and the resistance rotary switch are located on the panel of the housing, and the lead wire of the resistance rotary switch is connected to the main control module via a buffer.

[0013] Furthermore, the voltage measurement module is connected to the insulation resistance meter under test via a voltage measurement terminal, and includes a high-voltage divider, an automatic range selection circuit, and an analog-to-digital conversion circuit. The automatic range selection circuit is connected to the high-voltage divider and the analog-to-digital conversion circuit, respectively. The analog-to-digital conversion circuit is connected to the main control module, and the voltage measurement terminal is located on the panel of the enclosure.

[0014] Furthermore, the temperature and humidity acquisition module is an integrated temperature and humidity sensor, and the temperature and humidity control module includes a heating chip, a cooling fan, and a semiconductor cooler.

[0015] Furthermore, the vibration parameter acquisition module includes a laser displacement meter and an acceleration sensor.

[0016] Furthermore, the vibration table control module includes a drive unit and a guide mechanism. The drive unit includes a permanent magnet synchronous motor and a stacked piezoelectric ceramic actuator. The permanent magnet synchronous motor is used to adjust the low-frequency vibration frequency of the small vibration table, and the stacked piezoelectric ceramic actuator is used to adjust the high-frequency vibration frequency of the small vibration table. The guide mechanism is used to ensure that the vibration direction of the small vibration table is vertical.

[0017] Furthermore, a digital twin compensation model is constructed within the main control module, with the following formula:

[0018]

[0019] Among them, D_set is the target displacement command sent by the main control module, D_comp is the precision drive command output after full-element compensation, and α and β are the core parameters characterizing the first-order and second-order temperature coefficients. For dynamic terms, δ×Age_Factor is the aging term;

[0020] The insulation resistance meter calibration device performs calibration upon startup or periodically: the main control module applies a known test command D_set to the piezoelectric ceramic actuator, and simultaneously calls the integrated laser displacement meter to directly measure the actual output displacement D_actual of the actuator; the digital twin model predicts a displacement value D_pred based on the same input D_set; the error Err is calculated as D_actual - D_pred; if the error exceeds a preset threshold, an adaptive algorithm is activated to fine-tune the parameters α, β, and γ in the digital twin compensation model and update the digital twin compensation model.

[0021] The second objective of this invention can be achieved by adopting the following technical solution:

[0022] An insulation resistance meter calibration system is provided, the system comprising a host computer and the aforementioned insulation resistance meter calibration device, wherein a first communication module is connected to a second communication module of the host computer.

[0023] Furthermore, the host computer includes a database module, an image processing module, a certificate generation module, a graphical interface module, a vibration condition setting module, and a second communication module. The database module is connected to the image processing module, the certificate generation module, the graphical interface module, and the vibration condition setting module, respectively. The second communication module is connected to the graphical interface module. The image processing module is connected to the insulation resistance meter under test through an image acquisition module.

[0024] The image acquisition module is used to acquire the test data of the insulation resistance meter under test in real time.

[0025] The image processing module is used to locate and segment characters in the acquired raw image through connected component analysis, recognize characters using a convolutional neural network model, and generate raw readings; it processes the raw readings according to preset numerical rounding rules, and generates data records by combining the rounding results with the raw image and timestamp.

[0026] The third objective of this invention can be achieved by adopting the following technical solution:

[0027] An insulation resistance meter calibration method, implemented based on the aforementioned insulation resistance meter calibration system, the method comprising:

[0028] The insulation resistance meter calibration device controls the resistance acquisition, voltage measurement, temperature and humidity acquisition, and small vibration table operation through the main control module. It achieves real-time data transmission with the host computer through the first communication module, and the image acquisition module acquires the test data of the insulation resistance meter under test in real time. The database module adds vibration parameter tables and dynamic error tables, stores information on the insulation resistance meter calibration device, static calibration data, vibration condition data, and dynamic error results, and generates certificates by calling the data from the database module.

[0029] The present invention has the following advantages over the prior art:

[0030] 1. This invention enables condition-based verification, filling a gap in high-end equipment. By integrating a small vibration table, it achieves for the first time the integration of vibration conditions (low frequency, medium frequency, and impact) and insulation resistance meter verification for special equipment, quantifies dynamic errors, solves the problem of "qualified in the laboratory but failed in the field," and provides accurate metrological basis for the insulation safety of special equipment.

[0031] 2. This invention features high precision and high synergy, with vibration-verification data synchronized and dynamic error measurement accuracy of ±0.1%, ensuring that high voltage and high resistance measurements are unaffected by vibration and meeting the stringent metrological requirements of high-end equipment.

[0032] 3. This invention achieves integration and portability. Through the embedded design of a small vibration table, the device is small in size, supports laboratory and field testing, and solves the problems of cumbersome operation and large space occupation of the traditional "independent vibration table + calibration device".

[0033] 4. The high-end equipment of this invention has strong adaptability and conforms to high-end equipment standards such as GJB 151B and GJB 150A, meeting the needs of high-end equipment units for equipment anti-interference, environmental adaptability and data traceability.

[0034] 5. This invention features intelligent and efficient operation, and can automatically complete vibration condition setting, data acquisition, error calculation, and report generation without manual intervention. The verification efficiency is several times higher than that of traditional combined methods, thereby reducing the workload of metrology personnel in high-end equipment.

[0035] 6. This invention can realize a fully automated verification process, improving efficiency. Compared with the traditional verification that requires manual reading and recording of the displayed data of the insulation resistance meter under test, the addition of the image processing and recognition module can automatically collect the test data of the instrument under test, avoiding the delay problem of manual reading. Combined with the dynamic verification scenario of the vibration table, it can realize real-time data acquisition under high-frequency vibration. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0037] Figure 1 This is a structural block diagram of the insulation resistance meter calibration system according to an embodiment of the present invention.

[0038] Figure 2This is a schematic diagram of the housing in the insulation resistance meter calibration device according to an embodiment of the present invention.

[0039] Figure 3 This is a schematic diagram of the connection between the housing and the small vibration table in the insulation resistance meter calibration device according to an embodiment of the present invention.

[0040] Figure 4 This is a structural block diagram of the host computer in the insulation resistance meter calibration system of this invention.

[0041] Figure 5 This is a schematic diagram of the PID control principle in an embodiment of the present invention.

[0042] Figure 6 This is a flowchart illustrating the temperature compensation process according to an embodiment of the present invention.

[0043] Figure 7 This is a flowchart illustrating the certificate generation process according to an embodiment of the present invention.

[0044] The components are as follows: 1-Host computer, 2-Box, 3-Small vibration table, 4-Main control module, 5-Resistance output module, 6-Voltage measurement module, 7-Temperature and humidity acquisition module, 8-Temperature and humidity control module, 9-First communication module, 10-Vibration parameter acquisition module, 11-Vibration table control module, 12-Display module, 13-Resistance measurement terminal, 14-Resistance rotary switch, 15-Voltage measurement terminal, 16-USB communication port, 17-Power interface, 18-Power indicator light, 19-Alarm indicator light, 20-Shielding terminal, 21-Grounding terminal, 22-Handle, 23-Database module, 24-Image processing module, 25-Certificate generation module, 26-Graphical interface module, 27-Vibration condition setting module, 28-Second communication module. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0046] Example:

[0047] like Figures 1-3As shown, this embodiment provides an insulation resistance meter calibration system. The system includes a host computer 1 and an insulation resistance meter calibration device, which is a slave computer. The slave computer includes a housing 2 and a small vibration table 3. The small vibration table 3 is connected to the housing 2 by wires. The housing 2 is equipped with a main control module 4, a resistance output module 5, a voltage measurement module 6, a temperature and humidity acquisition module 7, a temperature and humidity control module 8, a first communication module 9, a vibration parameter acquisition module 10, and a vibration table control module 11. A display module 12 is provided on the panel of the housing 2. The main control module 4 is connected to the resistance output module 5, the voltage measurement module 6, the temperature and humidity acquisition module 7, the temperature and humidity control module 8, the first communication module 9, the vibration parameter acquisition module 10, the vibration table control module 11, and the display module 12. The vibration parameter acquisition module 10 and the vibration table control module 11 can communicate with the host computer 1 through the first communication module 9.

[0048] Furthermore, the resistance output module 5 is connected to the insulation resistance meter being measured via the resistance measurement terminal 13. It includes nine decimal resistance dials connected in series and one fixed resistance dial. Both the decimal and fixed resistance dials have corresponding rotary resistance switches 14. The resistance measurement terminal 13 and the rotary resistance switches 14 are located on the panel of the housing 2, and the leads of the rotary resistance switches 14 are connected to the main control module 4 via buffers. Specifically, the rotary resistance switches 14 corresponding to the nine decimal resistance dials are step-resistance rotary switches with a minimum step resistance of not less than 100Ω. The standard resistance of the decimal resistance dials is divided into nine levels: 10... 2 10 3 10 4 10 5 10 6 10 7 10 8 10 9 10 10 The fixed resistor disk can be set with precision resistors ranging from 100 to 900 GΩ, so that its output range reaches 1 TΩ. The buffer can be a tri-state output four-bus buffer. The main control module 4 can be an STM32 microcontroller. The display module 12 can be an LCD screen. The resistance value data is transmitted to the microcontroller by adjusting the resistor rotary switch 14 to realize the acquisition of the resistance value. The microcontroller processes the digital signal and displays the result on the LCD screen.

[0049] Furthermore, the voltage measurement module 6 is connected to the insulation resistance meter under test via the voltage measurement terminal 15. It includes a high-voltage divider, an automatic range selection circuit, and an analog-to-digital converter circuit. The automatic range selection circuit is connected to the high-voltage divider and the analog-to-digital converter circuit, respectively. The analog-to-digital converter circuit is connected to the main control module 4. The voltage measurement terminal 15 is located on the panel of the enclosure 2. Specifically, the high-voltage divider selects a series resistor with high voltage resistance for voltage division. The voltage is input through the L and E ports and can be divided into six ranges: 100V, 500V, 1kV, 2.5kV, 5kV, and 10kV. After the voltage terminal is connected, the voltage to be measured is input. The corresponding range is selected by the series resistor voltage divider circuit, and then converted into a digital signal suitable for microcontroller processing by the analog-to-digital converter. The microcontroller processes the digital signal and sends the processing result to the LCD screen for display.

[0050] Furthermore, the temperature and humidity acquisition module 7 employs an integrated temperature and humidity sensor. The temperature and humidity signals acquired by the integrated sensor are transmitted to the microcontroller via a bus for processing. The microcontroller obtains relevant control signals based on the processing results and then sends them to the temperature and humidity control module to implement corresponding control. Simultaneously, it sends the detected temperature and humidity values ​​to the LCD screen for display. Figure 5 As shown, if the temperature is not equal to the set value, the temperature and humidity control module 8 will be controlled by the PID control algorithm in the microcontroller. The temperature and humidity control module 8 includes actuators such as heating chip, cooling fan, and semiconductor cooler, which can realize the adjustment of temperature and humidity.

[0051] Furthermore, the vibration parameter acquisition module 10 includes a laser displacement meter and an accelerometer. The laser displacement meter is a miniature laser displacement meter, and the accelerometer is a MEMS accelerometer, enabling accurate acquisition of vibration parameters across the entire frequency range (5-1000Hz). The vibration table control module 11 includes a drive unit and a guide mechanism. The drive unit includes a permanent magnet synchronous motor and a stacked piezoelectric ceramic actuator. Specifically, the vibration parameter acquisition module 10 shares a single-chip microcomputer clock with the resistance output module 5 and the voltage measurement module 6, triggering simultaneous data acquisition. The frequency range of the small vibration table 3 is 5-1000Hz (covering...). The vibration frequency ranges from 10-50Hz for ships, 50-500Hz for aircraft, and 100-1000Hz for impact vibrations, with an amplitude range of 0-5mm (peak-to-peak). A permanent magnet synchronous motor is used to adjust the low-frequency vibration frequency of the small vibration table. It adopts a hollow cup-shaped micro moving coil and is equipped with a neodymium iron boron ring permanent magnet. The maximum thrust is 50N and the response time is ≤20ms. A stacked piezoelectric ceramic actuator is used to adjust the high-frequency vibration frequency of the small vibration table to meet the requirements of high frequency and small amplitude. The guide mechanism is used to ensure that the vibration direction of the small vibration table is vertical. It adopts a cross-shaped flexible hinge, with no mechanical friction and a guide accuracy of ≤0.001mm.

[0052] It can be seen that the small vibration table 3 adopts the "electromagnetic micro moving coil drive + flexible guidance + dual sensor feedback" solution, which is suitable for the miniaturization and high precision requirements of high-end equipment scenarios.

[0053] Furthermore, the first communication module 9 has a USB communication section and a WIFI communication section. The USB communication port 16 is located on the panel of the housing 2. Communication between the host computer 1 and the slave computer (insulation resistance meter calibration device) can be realized through the USB data cable. The WIFI communication section adopts ESP8622 to realize serial communication with the microcontroller. The instruction development is simple. The entire communication process can be divided into six parts: WIFI initialization, LWIP protocol control settings, query, connection establishment, data communication, and disconnection, so as to achieve a longer transmission distance and a higher transmission speed.

[0054] Furthermore, the panel of the enclosure 2 is also equipped with a power interface 17, a power indicator light 18, an alarm indicator light 19, a shielding terminal 20, and a grounding terminal 21. The power indicator light 18 lights up when the power is connected, the alarm indicator light 19 is controlled by a microcontroller and flashes when the temperature and humidity exceed the set values, the shielding terminal 20 is used to eliminate interference from surface leakage current and improve measurement accuracy, and the grounding terminal 21 is used for safety protection. The enclosure 2 is a rectangular sealed structure. In order to facilitate carrying the insulation resistance meter calibration device, a handle 22 is provided on the top of the enclosure 2.

[0055] In this embodiment, the insulation resistance meter calibration device's temperature and humidity control module forms the foundation for stable system operation. This module employs a closed-loop feedback control mechanism. After the microcontroller (STM32 microcontroller) sets the target temperature and humidity, a high-precision environmental sensor monitors them in real time. The built-in PID controller continuously calculates the deviation between the measured and set values, and accordingly drives actuators such as heating chips, cooling fans, or semiconductor coolers to adjust their actions, thereby accurately and stably maintaining the temperature and humidity within the device's internal space within the set range. This macroscopic control loop effectively combats environmental disturbances, providing a crucial and stable prerequisite for subsequent high-voltage output.

[0056] To overcome the accuracy degradation of the core actuator in macroscopic control caused by temperature drift, transient thermal stress, and long-term aging, the system introduces an innovative digital twin compensation model. This model serves as a dynamic mirror image of the physical actuator in digital space, and its core compensation formula can be expressed as:

[0057]

[0058] Where D_set is the target displacement command sent by the microcontroller, D_comp is the precision drive command output after full-element compensation, and α and β are the core parameters characterizing the first-order and second-order temperature coefficients. δ×Age_Factor is the dynamic term, and δ×Age_Factor is the aging term.

[0059] To ensure that the digital twin model and the physical entity remain highly synchronized at all times, the device runs an online self-calibration process upon startup or periodically: such as Figure 6 As shown, in this process, the microcontroller applies a known test command D_set to the piezoelectric ceramic actuator. Simultaneously, the system calls upon the integrated micro laser displacement gauge—a high-precision "ruler"—to directly measure the actuator's actual output displacement D_actual. The digital twin model then calculates a predicted displacement D_pred in parallel based on the same input D_set. The system subsequently calculates the error Err = D_actual - D_pred. If this error exceeds a preset tolerance, an adaptive algorithm (such as least squares or gradient descent) is automatically triggered to fine-tune and optimize the key parameters α, β, and γ in the model. This process iterates continuously, allowing the digital twin model to evolve and its predictive behavior to increasingly approximate the actual performance of the physical entity.

[0060] In actual operation, the above mechanisms constitute a collaborative intelligent whole. The initial displacement command D_set calculated by the macroscopic PID controller based on environmental deviations is first processed by the digital twin compensation model before being sent to the physical actuator. The model integrates the real-time collected actuator point temperature, temperature change rate, and cumulative aging factor, and instantly outputs a precisely corrected final command D_comp to drive the piezoelectric ceramic to complete ultra-high precision actions. This composite architecture of "macroscopic closed-loop feedback + microscopic feedforward compensation" elevates the traditional temperature and humidity control from a passive "sensing-response" mode to an active "prediction-compensation" intelligent system. It eliminates the drift caused by internal thermal disturbances and long-term aging at the root of the execution process, thereby ensuring that the insulation resistance meter calibration environment maintains extreme stability and accuracy throughout its entire life cycle.

[0061] like Figures 1-4As shown, the host computer 1 includes a database module 23, an image processing module 24, a certificate generation module 25, a graphical interface module 26, a vibration condition setting module 27, and a second communication module 28. The database module 23 is connected to the image processing module 24, the certificate generation module 25, the graphical interface module 26, and the vibration condition setting module 27, respectively. The second communication module 28 is connected to the graphical interface module 26. The image processing module 24 is connected to the insulation resistance meter under test through an image acquisition module. The insulation resistance meter calibration device controls the resistance acquisition, voltage measurement, temperature and humidity acquisition, and small vibration table operation through the main control module 4. Real-time data transmission with the host computer 1 is achieved through the first communication module 9. The image acquisition module acquires the test data of the insulation resistance meter under test in real time. The database module 23 adds vibration parameter tables and dynamic error tables, and stores information on the insulation resistance meter calibration device, static calibration data, vibration condition data, and dynamic error results. The data from the database module 23 is called to generate a certificate. The specific descriptions of the image acquisition module, image processing module, and certificate generation module are as follows:

[0062] Image acquisition module: The system controls the calibration source through a standard interface and connects to a fixed-angle camera. When the calibration source outputs a standard resistance value as instructed, the host computer software analyzes the video stream captured by the camera in real time. A lightweight CRNN model is used to perform real-time OCR recognition on the video frames. When the fluctuation range of the recognition results for 10 consecutive frames is less than the minimum resolution of the instrument, a high-resolution image is triggered. This image is then precisely bound to the standard value and timestamp output by the current standard source and transmitted to the host computer.

[0063] Image processing module: After the host computer acquires the image, it performs character localization and segmentation on the acquired raw image through connected component analysis, and uses a convolutional neural network model for character recognition to generate raw readings, such as... Figure 7 As shown, the data includes the serial number, production date, and testing date of the insulation resistance meter; the original readings are processed according to the preset numerical rounding rules, and the rounding results, together with the original image and timestamp, are used to generate data records and stored in the database module 23.

[0064] Certificate generation module: such as Figure 7 As shown, a simple user interface is designed using the PySimpleGUI module to facilitate user operation. The second communication module 28 enables interaction between electronic devices. The database module 23 uses MySQL to store the serial number, production date, test date, original records, and verification results of the insulation resistance meter. Finally, the Python program is called to perform calculations on the indication error, result judgment, and certificate generation.

[0065] In the description of this invention, it should be noted that, unless otherwise explicitly specified and agreed, the terms "set," "install," and "connect" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances. The terms "upper," "lower," "left," "right," and similar expressions used are for illustrative purposes only and do not represent the only possible implementation.

[0066] In summary, this invention, by integrating a small vibration table, can accurately simulate the low-frequency and medium-frequency vibrations and instantaneous impact conditions of special equipment, achieving miniaturization and integrated operation of the vibration table and calibration device. This meets the space requirements of high-end equipment laboratories and on-site testing, and adds image acquisition, recognition, and automatic test reading functions to achieve automated testing.

[0067] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope disclosed in the present invention, based on the technical solution and inventive concept of the present invention, shall fall within the scope of protection of the present invention.

Claims

1. An insulation resistance meter calibration device, characterized in that, The device includes a housing and a small vibration table. The small vibration table is connected to the housing via wires. The housing contains a main control module, a resistance output module, a voltage measurement module, a temperature and humidity acquisition module, a temperature and humidity control module, a first communication module, a vibration parameter acquisition module, and a vibration table control module. A display module is provided on the housing panel. The main control module is connected to the resistance output module, voltage measurement module, temperature and humidity acquisition module, temperature and humidity control module, first communication module, vibration parameter acquisition module, vibration table control module, and display module.

2. The insulation resistance meter calibration device according to claim 1, characterized in that, The resistance output module is connected to the insulation resistance meter being measured via the resistance measurement terminal. It includes nine decimal resistance disks connected in series and one fixed resistance disk. Each decimal resistance disk and the fixed resistance disk has a corresponding resistance rotary switch. The resistance measurement terminal and the resistance rotary switch are located on the panel of the enclosure, and the lead wire of the resistance rotary switch is connected to the main control module through a buffer.

3. The insulation resistance meter calibration device according to claim 1, characterized in that, The voltage measurement module is connected to the insulation resistance meter under test through the voltage measurement terminal. It includes a high voltage divider, an automatic range selection circuit, and an analog-to-digital conversion circuit. The automatic range selection circuit is connected to the high voltage divider and the analog-to-digital conversion circuit, respectively. The analog-to-digital conversion circuit is connected to the main control module. The voltage measurement terminal is located on the front panel of the enclosure.

4. The insulation resistance meter calibration device according to claim 1, characterized in that, The temperature and humidity acquisition module is an integrated temperature and humidity sensor, and the temperature and humidity control module includes a heating chip, a cooling fan, and a semiconductor cooler.

5. The insulation resistance meter calibration device according to claim 1, characterized in that, The vibration parameter acquisition module includes a laser displacement meter and an acceleration sensor.

6. The insulation resistance meter calibration device according to claim 1, characterized in that, The vibration table control module includes a drive unit and a guide mechanism. The drive unit includes a permanent magnet synchronous motor and a stacked piezoelectric ceramic actuator. The permanent magnet synchronous motor is used to adjust the low-frequency vibration frequency of the small vibration table, and the stacked piezoelectric ceramic actuator is used to adjust the high-frequency vibration frequency of the small vibration table. The guide mechanism is used to ensure that the vibration direction of the small vibration table is vertical.

7. The insulation resistance meter calibration device according to any one of claims 1-6, characterized in that, The main control module contains a digital twin compensation model, the formula of which is as follows: Among them, D_set is the target displacement command sent by the main control module, D_comp is the precision drive command output after full-element compensation, and α and β are the core parameters characterizing the first-order and second-order temperature coefficients. For dynamic terms, δ×Age_Factor is the aging term; The insulation resistance meter calibration device performs calibration upon startup or periodically: the main control module applies a known test command D_set to the piezoelectric ceramic actuator, and simultaneously calls the integrated laser displacement meter to directly measure the actual output displacement D_actual of the actuator; the digital twin model predicts a displacement value D_pred based on the same input D_set; the error Err is calculated as D_actual - D_pred; if the error exceeds a preset threshold, an adaptive algorithm is activated to fine-tune the parameters α, β, and γ in the digital twin compensation model and update the digital twin compensation model.

8. An insulation resistance meter calibration system, characterized in that, The system includes a host computer and an insulation resistance meter calibration device according to any one of claims 1-7, wherein the first communication module is connected to the second communication module of the host computer.

9. The insulation resistance meter calibration system according to claim 8, characterized in that, The host computer includes a database module, an image processing module, a certificate generation module, a graphical interface module, a vibration condition setting module, and a second communication module. The database module is connected to the image processing module, the certificate generation module, the graphical interface module, and the vibration condition setting module, respectively. The second communication module is connected to the graphical interface module. The image processing module is connected to the insulation resistance meter being measured through an image acquisition module. The image acquisition module is used to acquire the test data of the insulation resistance meter under test in real time. The image processing module is used to locate and segment characters in the acquired raw image through connected component analysis, recognize characters using a convolutional neural network model, and generate raw readings; it processes the raw readings according to preset numerical rounding rules, and generates data records by combining the rounding results with the raw image and timestamp.

10. A method for calibrating an insulation resistance meter, implemented based on the insulation resistance meter calibration system according to any one of claims 8-9, characterized in that, The method includes: The insulation resistance meter calibration device controls the resistance acquisition, voltage measurement, temperature and humidity acquisition, and small vibration table operation through the main control module. It achieves real-time data transmission with the host computer through the first communication module, and the image acquisition module acquires the test data of the insulation resistance meter under test in real time. The database module adds vibration parameter tables and dynamic error tables, stores information on the insulation resistance meter calibration device, static calibration data, vibration condition data, and dynamic error results, and generates certificates by calling the data from the database module.

Images