Transformer type differential signal acquisition system and method

Abstract

The invention provides a transformer type differential signal acquisition system and method, and relates to the technical field of signal acquisition, and the system comprises a switching power supply module which is used for supplying power to the system; the input module is used for collecting wire feedback signals; the operational circuit is used for rectifying the feedback signal, performing differential processing and filtering on the rectified feedback signal to obtain a differential filtering signal, adding bias voltage to the differential filtering signal, and amplifying the differential filtering signal to obtain an amplified signal; the analog-to-digital conversion module is used for converting the amplified signal into a digital signal; the CPU processing module is used for processing the digital signal, generating a control signal and sending the control signal to the output module and the communication module; the output module is used for generating current according to the control signal; and the communication module is used for sending the control signal to an upper computer through the communication interface, so that the upper computer calibrates the linear variable differential transformer. The linear variable differential transformer has the technical effect that the measurement precision of the linear variable differential transformer is improved.

Description

Technical Field

[0001] The present application relates to the technical field of signal acquisition, and in particular to a transformer-type differential signal acquisition system and method. Background Art

[0002] In the field of modern industrial automation and precision measurement, high-precision displacement measurement plays a vital role. As a widely used displacement sensor, linear variable differential transformer (LVDT) is well-known for its high precision, good linearity and stability. However, in practical applications, how to accurately and reliably collect and process the output signal of LVDT while ensuring that the system has sufficient flexibility to adapt to different working environments and requirements has always been a technical problem that needs to be solved.

[0003] In the prior art, analog circuits are usually used to process the output signals of LVDT, including amplification, rectification, filtering and other steps, and then the signals are converted into digital form by analog-to-digital converters for further processing. Although this method can achieve basic signal acquisition and processing functions, analog circuits are easily affected by factors such as temperature changes, electromagnetic interference, and component aging, which causes parameters such as gain and bias to drift during signal processing, thereby affecting measurement accuracy. Summary of the invention

[0004] The present application provides a transformer-type differential signal acquisition system for improving the measurement accuracy of a linear variable differential transformer.

[0005] In a first aspect, the present application provides a transformer-type differential signal acquisition system, the system comprising: a switching power supply module, an input module, an operation circuit, an analog-to-digital conversion module, a CPU processing module, an output module and a communication module; the switching power supply module is used to supply power to the operation circuit, the analog-to-digital conversion module, the CPU processing module and the communication module; the input module is used to collect the feedback signal of the linear variable differential transformer; the operation circuit is used to rectify the feedback signal, perform differential processing and filtering on the rectified feedback signal to obtain a differential filtered signal, and amplify the differential filtered signal after adding a preset bias voltage to obtain an amplified signal; the analog-to-digital conversion module is used to convert the amplified signal into a digital signal, and send the digital signal to the CPU processing module through an isolation chip; the CPU processing module is used to receive the digital signal, process the digital signal, generate a control signal, and send the control signal to the output module and the communication module; the output module is used to generate a current according to the control signal; the communication module is used to send the control signal to a host computer through a communication interface, so that the host computer calibrates the linear variable differential transformer.

[0006] By adopting the above technical solutions, the transformer-type differential signal acquisition system effectively improves the measurement accuracy and reliability of the linear variable differential transformer (LVDT) through its unique structural design and signal processing method. The system uses differential processing and filtering technology to suppress interference, and improves signal quality through high-precision analog-to-digital conversion and digital signal processing. The system introduces an automatic calibration function for communication with the host computer to achieve real-time compensation and long-term stability. The combination of these features not only solves the problem of analog circuits being susceptible to interference and difficult to ensure long-term stability in the prior art, but also improves the flexibility and adaptability of the system, improves the measurement accuracy of the linear variable differential transformer, and provides strong support for the promotion and use of LVDT in high-precision application scenarios.

[0007] Optionally, the CPU processing module is communicatively connected to an EEPROM chip storage module via a digital bus, and the EEPROM chip storage module is used to store characteristic parameters and calibration data of the linear variable differential transformer.

[0008] By adopting the above technical solution, the system significantly improves the management capability of the characteristic parameters and calibration data of the linear variable differential transformer (LVDT) by introducing the EEPROM chip storage module and establishing a digital bus communication connection with the CPU processing module. The non-volatile nature of the EEPROM chip ensures that the key data of the LVDT can be safely saved even in the event of a power outage. This not only simplifies the initialization process of the system, but also enables the CPU processing module to quickly access and apply the stored characteristic parameters and calibration data, thereby achieving more accurate signal processing and compensation. In addition, this design enhances the flexibility of the system, enabling it to adapt to different models of LVDTs and quickly adjust parameters when working conditions change, further improving measurement accuracy and system reliability.

[0009] Optionally, the CPU processing module is also used to read the characteristic parameters and the calibration data in the EEPROM chip storage module, and calibrate and convert the digital signal according to the characteristic parameters and the calibration data to obtain a displacement value corresponding to the actual displacement of the linear variable differential transformer.

[0010] By adopting the above technical solution, the solution reads the characteristic parameters and calibration data in the EEPROM chip storage module through the CPU processing module, and uses these data to calibrate and convert the digital signal, thereby realizing the accurate mapping from the original signal to the actual displacement. This design significantly improves the measurement accuracy of the linear variable differential transformer (LVDT) and effectively compensates for the nonlinear characteristics and individual differences of the LVDT. At the same time, due to the real-time calibration using the stored parameters, the system can adapt to the performance changes of the LVDT under different working conditions, ensuring the consistency and reliability of the measurement results. In addition, this method simplifies the calibration process, reduces human errors, and improves the flexibility of the system, making it easy to adapt to different models of LVDT, thereby expanding the application range of the system.

[0011] Optionally, the CPU processing module is further used to generate the control signal according to the displacement value, and send the control signal to the output module and the communication module.

[0012] By adopting the above technical solution, the CPU processing module generates a control signal according to the calculated displacement value, and sends it to the output module and the communication module, realizing the closed-loop control and data interaction functions of the system. This design ensures the accurate correspondence between the output signal and the actual displacement, and improves the measurement accuracy and response speed of the system. Through the output module, the system can provide standardized control signals to external devices, which is convenient for integration with other industrial equipment. At the same time, sending the control signal to the communication module enables the system to interact with the host computer in real time, realize remote monitoring, data recording and advanced analysis functions, and enhance the operability and scalability of the system. This comprehensive processing and multi-channel output method not only improves the overall performance of the linear variable differential transformer (LVDT) measurement system, but also enhances its adaptability and practicality in complex industrial environments.

[0013] Optionally, the external interface of the communication module is connected to the base plate through a 64-core socket with long and short pins and a 32-core socket, and then connected to the communication, calibration and output functions of the host computer through the wiring terminals on the base plate.

[0014] By adopting the above technical solution, the external interface of the communication module is connected to the base plate by using a 64-core socket with long and short pins and a 32-core socket, and then the communication, calibration and output function connection with the host computer is realized through the wiring terminals on the base plate, forming a flexible and reliable modular design. This connection method not only simplifies the assembly and maintenance process of the system, but also improves the stability and anti-interference ability of signal transmission. The long and short pin design ensures the safety during the plugging and unplugging process and reduces the risk of misoperation. The use of multi-core sockets increases the scalability of the system and can support more signal types and functions. The final connection is made through the wiring terminals on the base plate, which provides flexible interface selection and facilitates the system to be compatible with different types of host computers and external devices. This modular and standardized interface design significantly improves the adaptability, maintainability and upgrade potential of the system, and facilitates the application of linear variable differential transformer (LVDT) measurement systems in various industrial environments.

[0015] Optionally, the system further includes a programmer; wherein the programmer is connected to the CPU processing module via a programming interface, and is used to program and debug the CPU processing module.

[0016] By adopting the above technical solution, introducing a programmer and connecting to the CPU processing module through a programming interface, the system is provided with flexible programming and debugging capabilities. This design enables the system to quickly update programs and adjust parameters according to different application scenarios and requirements, improving the adaptability and customizability of the system. Through the programmer, technicians can directly access and modify the program of the CPU processing module, which is convenient for real-time optimization of algorithms, adjustment of processing logic, and addition of new functions, thereby improving the performance and functionality of the linear variable differential transformer (LVDT) measurement system. At the same time, this method simplifies the process of system maintenance and troubleshooting, reduces downtime, and improves system reliability and work efficiency. The existence of a programming interface also provides the system with the possibility of future upgrades and expansions, enabling it to continuously adapt to new technical requirements and application needs, extending the life cycle of the system and improving the return on investment.

[0017] Optionally, the CPU processing module adopts a high-stability and high-speed single-chip microcomputer, which is connected to the communication module through a digital bus, and the CPU processing module is connected to an external programmer through telecommunications.

[0018] By adopting the above technical solutions and using a high-stability and high-speed single-chip microcomputer as the CPU processing module, the processing capacity and reliability of the system are significantly improved. By connecting with the communication module through the digital bus, high-speed and stable data transmission is achieved, and the system response speed and communication efficiency are improved. The use of a telecommunications external programmer provides a convenient programming and debugging interface for the system, enhancing the flexibility and maintainability of the system. This design not only ensures the high accuracy and high stability of the linear variable differential transformer (LVDT) measurement system, but also enables the system to quickly adapt to different application requirements. The use of a high-speed single-chip microcomputer enables the system to execute more complex data processing algorithms, improving the accuracy and efficiency of signal processing.

[0019] In a second aspect, the present application provides a transformer-type differential signal acquisition method, the method comprising: acquiring a feedback signal of a linear variable differential transformer; rectifying the feedback signal, performing differential processing and filtering on the rectified feedback signal to obtain a differential filtered signal, adding a preset bias voltage to the differential filtered signal and amplifying it to obtain an amplified signal; converting the amplified signal into a digital signal; processing the digital signal to generate a control signal; generating a current according to the control signal, and sending the control signal to a host computer through a communication interface so that the host computer calibrates the linear variable differential transformer.

[0020] In summary, the present application includes at least one of the following beneficial technical effects: The transformer-type differential signal acquisition system effectively improves the measurement accuracy and reliability of the linear variable differential transformer (LVDT) through its unique structural design and signal processing method. The system uses differential processing and filtering technology to suppress interference, and improves signal quality through high-precision analog-to-digital conversion and digital signal processing. The system introduces an automatic calibration function for communication with the host computer to achieve real-time compensation and long-term stability. The combination of these features not only solves the problem of analog circuits being susceptible to interference and difficult to ensure long-term stability in the existing technology, but also improves the flexibility and adaptability of the system, improves the measurement accuracy of the linear variable differential transformer, and provides strong support for the promotion and use of LVDT in high-precision application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural schematic diagram of a transformer-type differential signal acquisition system provided in an embodiment of the present application; Figure 2 It is a schematic diagram of sampling input signal processing of a transformer-type differential signal acquisition system provided in an embodiment of the present application; Figure 3 It is a flow chart of a transformer-type differential signal acquisition method provided in an embodiment of the present application. DETAILED DESCRIPTION

[0022] In order to enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification will be clearly and completely described below in conjunction with the drawings in the embodiments of this specification. Obviously, the described embodiments are only part of the embodiments of this application, not all of the embodiments.

[0023] In the description of the embodiments of the present application, words such as "illustrative", "for example" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "illustrative", "for example" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "illustrative", "for example" or "for example" is intended to present related concepts in a concrete way.

[0024] Figure 1 It is a flow chart of a method for detecting the global temperature distribution of a nacelle equipped with a turboprop engine provided in an embodiment of the present application.

[0025] like Figure 1 As shown, a transformer-type differential signal acquisition system is provided, which is mainly used to process the signal of a linear variable differential transformer (LVDT). The system includes a switching power supply module, an input module, an operation circuit, an analog-to-digital conversion module, a CPU processing module, an output module and a communication module, which work together to achieve high-precision acquisition, processing and output of LVDT signals.

[0026] First of all, the switching power supply module provides a stable and reliable power supply for the core components of the system. This is because in the signal processing process, a stable power supply is essential to ensure the accuracy of the signal and the reliability of the system. The switching power supply module ensures the normal operation of each module by supplying power to the operation circuit, analog-to-digital conversion module, CPU processing module and communication module respectively. At the same time, it also realizes electrical isolation between different functional modules, effectively reducing the possibility of mutual interference.

[0027] Specifically, the switching power supply module has three output paths. One path is converted from 24VDC to 3.3V through a power regulator to power the CPU processing module and the communication module connected to the CPU processing module with a digital circuit. One path is converted from 24VDC to ±15V through a power regulator to power the operation circuit. One path is converted from 24VDC to 5V through a power regulator to power the analog-to-digital conversion module, thereby realizing power isolation between the channel part and the digital part of the system.

[0028] The input module is responsible for collecting the feedback signal of the LVDT. As a high-precision displacement sensor, the output signal of the LVDT is usually an AC voltage, which needs special processing before it can be used for subsequent digital processing. The design of the input module needs to take into account the signal's weakness and anti-interference to ensure that the collected original signal is as accurate as possible.

[0029] Next, the operation circuit performs a series of processing on the collected feedback signal. The first is rectification, which converts the AC signal into a DC signal, because the subsequent digital processing requires a stable DC signal. Then differential processing and filtering are performed. Differential processing can effectively eliminate common-mode interference and improve the signal-to-noise ratio, while filtering can remove high-frequency noise and make the signal smoother. After these processes, the obtained differential filter signal is purer and more stable. Subsequently, the operation circuit adds a preset bias voltage to the differential filter signal and amplifies it. The purpose of adding the bias voltage is to adjust the signal to a suitable voltage range to match the input requirements of the subsequent analog-to-digital conversion module, and the purpose of amplification is to improve the resolution of the signal so that even small changes can be accurately captured.

[0030] like Figure 2 As shown, Figure 2 It is a schematic diagram of sampling input signal processing of a transformer-type differential signal acquisition system provided in an embodiment of the present application.

[0031] First, the original signal from the linear variable differential transformer (LVDT) enters the system. The original signal here can be input signal 1, input signal 2, input signal 3, and input signal 4. As a high-precision displacement sensor, the output signal of LVDT is usually an AC voltage, and its amplitude is proportional to the displacement. This original signal first passes through a preamplifier. The role of the preamplifier is to amplify the weak LVDT output signal to a level suitable for subsequent processing while maintaining the linearity and low noise characteristics of the signal.

[0032] The amplified signal then enters a bandpass filter. The introduction of the bandpass filter has several important purposes: first, it can effectively remove DC bias and low-frequency interference in the signal, which may come from power supply fluctuations or ambient temperature changes; second, it can suppress high-frequency noise, including electromagnetic interference and thermal noise; finally, it can extract useful signal components near the LVDT excitation frequency and improve the signal-to-noise ratio. The center frequency of the bandpass filter is usually set to coincide with the excitation frequency of the LVDT, and the bandwidth is determined according to the dynamic response requirements of the system.

[0033] The filtered signal is then fed into a precision rectifier. The function of the rectifier is to convert the AC signal into a DC signal, which is convenient for subsequent analog-to-digital conversion and digital processing. In this embodiment, a full-wave rectifier circuit can be used to make full use of the full cycle information of the signal and improve the measurement accuracy and response speed.

[0034] The rectified signal then passes through a low-pass filter. The main function of this low-pass filter is to smooth the rectified pulsating DC signal and convert it into a stable DC voltage. The cutoff frequency of the filter needs to be carefully designed to strike a balance between signal smoothness and system response speed.

[0035] After the signal is processed by the low-pass filter, it has been transformed from a pulsating DC to a relatively stable DC voltage. This stable DC signal then enters the amplifier stage.

[0036] Finally, the signal after a series of analog processing is sent to the analog-to-digital conversion module, which can be an analog-to-digital converter (ADC). The ADC converts the continuous analog signal into a discrete digital signal to facilitate subsequent digital processing and control. In this embodiment, a high-resolution ADC (such as 16 bits or 24 bits) may be used to ensure that the digitization process does not introduce significant quantization errors.

[0037] The analog-to-digital conversion module converts the processed analog signal into a digital signal. This step is to convert the continuous analog quantity into a discrete digital quantity, laying the foundation for subsequent digital processing. The analog-to-digital conversion module uses a high-precision ADC chip to ensure that the accuracy loss during the conversion process is minimized. It is worth noting that the analog-to-digital conversion module sends the digital signal to the CPU processing module through an isolation chip. This isolation design can effectively prevent the noise of the digital circuit from interfering with the analog circuit, further improving the system's anti-interference ability and reliability.

[0038] The CPU processing module is the core of the entire system. It receives the digital signal from the analog-to-digital conversion module and processes it. The processing process may include algorithms such as digital filtering, linearization compensation, and temperature compensation. The purpose of these algorithms is to further improve the accuracy and reliability of the signal. After processing, the CPU generates a control signal and sends it to the output module and the communication module.

[0039] The output module generates the corresponding current output according to the control signal generated by the CPU processing module. Usually, this output adopts the industrial standard 4-20mA current signal, which has the characteristics of strong anti-interference ability and long transmission distance, and is suitable for use in industrial environments.

[0040] Finally, the communication module sends the control signal to the host computer through the communication interface. The purpose of this step is to realize data exchange between the system and external devices, so that the host computer can calibrate the LVDT. The calibration process is a key step to ensure measurement accuracy. Through calibration, an accurate correspondence between the LVDT output signal and the actual displacement can be established, thereby improving the accuracy of the entire measurement system.

[0041] Through the collaborative work of the above modules, the transformer-type differential signal acquisition system realizes high-precision acquisition, processing and output of LVDT signals. The modular design of the system not only improves the overall performance, but also enhances the flexibility and maintainability of the system. At the same time, the various signal processing technologies and isolation designs adopted effectively improve the anti-interference ability and reliability of the system, enabling the system to work stably and reliably in complex industrial environments, providing strong support for precision measurement and control applications.

[0042] The various modules mentioned in this application can be specifically implemented as follows: The switching power supply module can adopt a high-efficiency switching power supply design, such as a Buck or Boost converter using PWM control. This design can provide multiple stable outputs, such as 3.3V, 5V, and ±15V, to meet the power supply requirements of different modules. The module may contain EMI filtering circuits and overvoltage protection circuits to improve the stability and safety of the power supply.

[0043] The input module can be composed of a high-precision instrumentation amplifier, such as AD8421 or INA118. These amplifiers have high common-mode rejection ratio and low noise characteristics, which are very suitable for amplifying the weak signal of LVDT. The module may also contain anti-interference filtering circuits, such as RC low-pass filters, to filter out high-frequency noise.

[0044] The operational circuit can be composed of an array of precision operational amplifiers, such as the OPA4277 or AD8674. These operational amplifiers are used for rectification, differential processing, and amplification of the signal. The rectification circuit can be designed with a precision full-wave rectifier, the differential circuit can be configured with a differential amplifier, and the filtering can be designed with an active filter, such as a low-pass filter in a Sallen-Key topology.

[0045] The analog-to-digital conversion module can use high-precision ADC chips, such as the 24-bit ADS1255 or the 16-bit AD7606. These ADCs have high resolution and low noise characteristics, suitable for precision measurement applications. Isolation can be achieved through digital isolators, such as the ADUM1400 series, which provide galvanic isolation to enhance the system's anti-interference ability.

[0046] The CPU processing module can use a high-performance 32-bit microcontroller, such as the STM32F4 series or TI's TMS320F28335. These processors have powerful computing capabilities and rich peripheral interfaces, and can efficiently process complex digital signal processing algorithms.

[0047] The output module can use a high-precision digital-to-analog converter (DAC) and a voltage-to-current conversion circuit. The DAC can use a 16-bit or higher resolution chip, such as the AD5760. The voltage-to-current conversion can use a current source circuit composed of a precision operational amplifier and MOSFET to ensure the linearity and accuracy of the 4-20mA output.

[0048] The communication module can contain multiple communication interfaces, such as RS-485, CAN, Ethernet, etc. You can use dedicated communication interface chips, such as MAX485 (for RS-485) or MCP2515 (for CAN). For Ethernet communication, you can use an MCU with PHY or a separate Ethernet controller such as ENC28J60.

[0049] The specific implementation of these modules can be selected and optimized according to the actual application needs and performance requirements. The modular design allows the flexible replacement or upgrade of individual modules to adapt to different application scenarios or performance requirements while keeping the overall system architecture unchanged. For example, a higher resolution ADC can be selected when higher precision is required; a higher performance CPU can be selected when faster processing speed is required.

[0050] By carefully selecting the specific implementation of each module, a high-performance, high-reliability transformer-based differential signal acquisition system can be built to meet the stringent requirements of various industrial measurement and control applications.

[0051] like Figure 1 As shown, the figure also includes an EEPROM chip storage module, which is connected to the CPU processing module through a digital bus. The EEPROM chip storage module is used to store characteristic parameters and calibration data of the linear variable differential transformer.

[0052] Specifically, the main function of the EEPROM chip storage module is to store the characteristic parameters and calibration data of the LVDT. As a high-precision displacement sensor, the relationship between the output signal and the actual displacement of the LVDT is usually not completely linear, and may be affected by environmental factors such as temperature and humidity. In order to obtain accurate displacement measurement results, the LVDT needs to be calibrated and the calibration data needs to be stored for compensation in actual use.

[0053] EEPROM (Electrically Erasable Programmable Read-Only Memory) chips are selected as storage modules mainly because of their non-volatility, multiple erasable and fast read speed. These characteristics make EEPROM very suitable for storing data that needs to be stored for a long time and updated occasionally, such as LVDT characteristic parameters and calibration data. EEPROM can achieve fast and reliable data reading and writing by connecting to the CPU processing module through a digital bus (such as I2C or SPI).

[0054] In practical applications, the workflow of the EEPROM chip storage module is as follows: First, during the initial calibration of the LVDT, the output of the LVDT at different displacement points is accurately measured by a host computer or a special calibration device to obtain a series of input-output correspondences. These data points can be used to fit the characteristic curve of the LVDT, or directly used as a lookup table. At the same time, measurements can also be performed under different temperature conditions to obtain temperature compensation coefficients. These characteristic parameters and calibration data are then written into the EEPROM.

[0055] When the system is operating normally, the CPU processing module will read these stored parameters and data from the EEPROM at startup or when needed. When receiving the digital signal processed by the analog-to-digital conversion module, the CPU processing module can use the stored characteristic parameters and calibration data to calibrate and compensate the original data. For example, the ADC reading can be converted into an actual displacement value through methods such as interpolation algorithms or polynomial fitting. If the temperature compensation coefficient is stored, further compensation can be performed based on the current temperature to obtain a more accurate measurement result.

[0056] The CPU processing module is also used to read the characteristic parameters and calibration data in the EEPROM chip storage module, and calibrate and convert the digital signal according to the characteristic parameters and calibration data to obtain a displacement value corresponding to the actual displacement of the linear variable differential transformer.

[0057] In one example, when the system starts, the CPU processing module reads the stored LVDT characteristic parameters and calibration data from the EEPROM chip storage module through a digital bus (such as I2C or SPI). These data may include the linearity correction coefficient, temperature compensation coefficient, zero offset, etc. of the LVDT. The purpose of reading these data is to provide the necessary calibration information for subsequent signal processing.

[0058] Next, when the CPU processing module receives digital signals from the analog-to-digital conversion module, it calibrates and converts these digital signals according to the pre-read characteristic parameters and calibration data. This process can be divided into several steps: Linearity Correction: There may be a nonlinear relationship between the output signal of the LVDT and the actual displacement. The CPU processing module can use the linearity correction coefficients stored in the EEPROM to convert the raw digital signal into a more linear signal through methods such as polynomial fitting or lookup table interpolation.

[0059] Temperature compensation: The output of an LVDT may be affected by temperature changes. If a temperature sensor is included in the system, the CPU processing module can read the current temperature and use the temperature compensation coefficient stored in the EEPROM to adjust the signal to eliminate errors caused by temperature changes.

[0060] Zero and span adjustment: Using the zero offset and full-scale values ​​stored in the EEPROM, the CPU processing module can accurately scale the calibrated signal to correspond to the actual displacement.

[0061] Digital filtering: To further improve the stability of the measurement, the CPU processing module may also perform digital filtering on the signal, such as using algorithms such as moving average or Kalman filtering to reduce the impact of random noise.

[0062] After this series of processing, the CPU processing module finally obtains the accurate displacement value corresponding to the actual displacement of the LVDT. This displacement value not only reflects the actual physical displacement of the LVDT, but also includes compensation for various non-ideal factors.

[0063] The CPU processing module is also used to generate a control signal according to the displacement value and send the control signal to the output module and the communication module.

[0064] In one example, first, the CPU processing module generates a corresponding control signal based on the precise displacement value obtained in the previous step. This process may involve multiple steps, including signal mapping, application of proportional-integral-derivative (PID) control algorithm, output limiting, etc. For example, the CPU may map the displacement value into a predefined control range, and then apply the PID algorithm to generate a smooth control output to avoid sudden changes that may cause system instability. At the same time, the CPU also ensures that the generated control signal does not exceed the safe operating range of the system.

[0065] Next, the CPU processing module sends the generated control signal to the output module and the communication module at the same time. The purpose of sending the control signal to the output module is to generate a standardized analog output, usually a 4-20mA current signal or a 0-10V voltage signal. This standardized output signal can be directly interfaced with other industrial control devices (such as programmable logic controllers PLCs or distributed control systems DCS) for further process control or monitoring.

[0066] At the same time, the CPU processing module will also send the control signal to the communication module. The purpose of this step is to realize data exchange between the system and the host computer or other intelligent devices. The communication module may support a variety of industrial communication protocols, such as Modbus, PROFIBUS, EtherNet / IP, etc. Through these protocols, the control signal can be packaged into a standard data frame and then sent out through a communication interface (such as RS-485, Ethernet, etc.). This allows the host computer to monitor the displacement of the LVDT in real time, perform data recording, trend analysis, and even remotely adjust system parameters.

[0067] The external interface of the communication module is connected to the base plate through a 64-core socket with long and short pins and a 32-core socket, and then connected to the communication, calibration and output functions of the host computer through the wiring terminals on the base plate.

[0068] Specifically, the circuit board of the communication module is designed with corresponding 64-core and 32-core socket interfaces. These sockets adopt a long-short pin design, in which the long pin is used to transmit key signals and power, and the short pin is used for secondary signals or redundant connections. The purpose of the long-short pin design is to ensure that during the plug-in process, key connections (such as power and ground) are established first and then disconnected, thereby increasing the reliability and safety of the system. The 64-core socket may be mainly used for data transmission and control signals, while the 32-core socket may be used for power supply and auxiliary functions.

[0069] These sockets are connected to the corresponding slots on the baseboard. As an intermediate layer, the baseboard plays the role of signal routing and distribution. It not only simplifies the connection between modules, but also provides a unified interface platform. There are multiple wiring terminals designed on the baseboard, which are connected to the various pins of the sockets and finally lead out to the external interface.

[0070] The use of wiring terminals makes the connection between the system and the host computer more flexible and convenient. Through these terminals, the system can easily establish communication connections with various host computer devices to achieve data exchange and remote control. At the same time, these terminals also provide a calibration interface for the system, allowing technicians to perform on-site calibration without disassembling the equipment. In addition, the output function is also realized through these terminals, which can be directly connected to other control devices or display units.

[0071] like Figure 1 As shown, Figure 1 The programmer is also included; wherein the programmer is connected to the CPU processing module through a programming interface and is used to program and debug the CPU processing module.

[0072] In one example, first, a dedicated programming interface is reserved on the CPU processing module. This interface usually adopts a standardized design, such as the JTAG (Joint Test Action Group) interface or the SWD (Serial Wire Debug) interface. These interfaces not only support the download and debugging of programs, but also allow real-time monitoring of the CPU's operating status. The physical implementation of the programming interface may be a small multi-pin connector located on the circuit board of the CPU processing module to facilitate the connection of an external programmer.

[0073] The programmer itself is an independent hardware device that usually contains the necessary circuits to support communication and control with the CPU processing module. It may be equipped with a USB interface to connect to the development computer. When the CPU processing module needs to be programmed or debugged, the developer only needs to connect the programmer to the programming interface of the CPU processing module and operate it through the development software.

[0074] The programming and debugging process usually includes the following steps: Program writing and compilation: Developers write or modify program code in the development environment and then compile it to generate executable files.

[0075] Program download: Download the compiled program to the flash memory of the CPU processing module through the programmer.

[0076] Program Verification: After downloading is complete, the programmer will automatically verify the integrity of the program to ensure that the download process is correct.

[0077] Debugging: Developers can set breakpoints, single-step through the program, view variable values ​​in real time, etc. to verify the correctness and performance of the program.

[0078] Parameter configuration: Through the programming interface, various parameters of the system can be adjusted and optimized in real time.

[0079] The CPU processing module adopts a high-stability and high-speed single-chip microcomputer, which is connected to the communication module through a digital bus, and the CPU processing module is connected to an external programmer through telecommunications.

[0080] In this embodiment, the core of the CPU processing module adopts a high-stability and high-speed single-chip microcomputer. This choice reflects the system's high attention to performance and reliability. High stability ensures the stable operation of the system in various industrial environments, while high-speed characteristics meet the needs of complex signal processing and real-time control. The selection of this single-chip microcomputer provides powerful and reliable computing and control capabilities for the entire transformer-type differential signal acquisition system.

[0081] The CPU processing module is connected to the communication module through a digital bus. The choice of this connection method is based on several important considerations. First, the digital bus provides a high-speed and reliable data transmission channel that can meet the system's requirements for real-time and data integrity. Common digital buses such as I2C, SPI or UART not only have fast transmission speeds, but also have strong anti-interference capabilities, making them very suitable for use in industrial environments. Secondly, the use of digital buses simplifies the hardware design of the system, reduces the number of signal lines, and improves the integration and reliability of the system. In addition, the standardized nature of the digital bus makes the system have good scalability, which is convenient for adding new functional modules or upgrading existing modules in the future.

[0082] In terms of programming and debugging, the CPU processing module is connected to an external programmer through a dedicated interface. The main purpose of this design is to facilitate the initial programming, debugging, and subsequent maintenance and upgrades of the system. In specific implementation, a dedicated programming interface, such as JTAG or SWD interface, is reserved on the CPU processing module. These interfaces not only support program downloads, but also allow real-time debugging and system status monitoring. The external programmer can be a dedicated hardware device or a PC-based software tool with a simple hardware adapter.

[0083] The present application also discloses a transformer-type differential signal acquisition method, such as Figure 3 As shown, Figure 3 : is a flow chart of a transformer-type differential signal acquisition method provided in an embodiment of the present application, which specifically includes S101-S105: S101, collecting feedback signals of a linear variable differential transformer.

[0084] S102, rectifying the feedback signal, performing differential processing and filtering on the rectified feedback signal to obtain a differential filtered signal, adding a preset bias voltage to the differential filtered signal and amplifying it to obtain an amplified signal.

[0085] S103, converting the amplified signal into a digital signal.

[0086] S104, processing the digital signal to generate a control signal.

[0087] S105, generating a current according to the control signal, and sending the control signal to a host computer through a communication interface, so that the host computer calibrates the linear variable differential transformer.

[0088] In one example, the transformer-type differential signal acquisition method disclosed in the present application is intended to improve the accuracy, reliability and flexibility of linear variable differential transformer (LVDT) signal acquisition. Through a series of carefully designed signal processing steps, the method not only achieves high-quality signal acquisition, but also provides an automatic calibration function, greatly improving the overall performance and ease of use of the system.

[0089] The first step of the method is to collect the feedback signal of the LVDT. As a high-precision displacement sensor, the output of the LVDT is usually an AC voltage signal that is proportional to the displacement. This raw signal contains displacement information, but it may also be mixed with various noises and interferences. Therefore, the subsequent processing steps are crucial to extract accurate displacement information.

[0090] Next, the method rectifies the feedback signal. The purpose of rectification is to convert the AC signal into a unidirectional pulsating DC signal, which lays the foundation for subsequent differential processing and filtering. The rectified signal is then differentially processed and filtered. Differential processing can effectively suppress common-mode interference and improve the signal's ability to resist noise, while filtering further removes unwanted high-frequency components and improves the purity of the signal. The combination of these two steps produces a differential filtered signal, which has a higher signal-to-noise ratio and better stability than the original signal.

[0091] In order to adapt the signal to the subsequent digital conversion process, the method adds a preset bias voltage to the differential filter signal and amplifies it. The purpose of adding the bias voltage is to adjust the signal to the input range suitable for the analog-to-digital converter, while the purpose of amplification is to make full use of the dynamic range of the analog-to-digital converter and improve the resolution of the digitization process. The amplified signal generated by this step has a suitable amplitude and bias, which is ready for high-precision analog-to-digital conversion.

[0092] Subsequently, the method converts the amplified signal into a digital signal. This step is completed by a high-resolution analog-to-digital converter, which converts the continuous analog signal into a discrete digital signal. Digitization not only facilitates subsequent signal processing and analysis, but also improves the signal's anti-interference ability and reliability of long-distance transmission.

[0093] Processing the digital signal to generate a control signal is the next key step in the method. This process may involve multiple algorithms such as digital filtering, linearization, and temperature compensation to further improve the accuracy and reliability of the signal. The generated control signal not only contains precise displacement information, but may also include additional data such as system status and diagnostic information.

[0094] Finally, the method generates current according to the control signal and sends the control signal to the host computer through the communication interface. The generated current can be used to drive the actuator or other control purposes, and the signal sent to the host computer is used to realize the automatic calibration of the LVDT. This design greatly improves the flexibility and ease of use of the system. Through calibration by the host computer, it can quickly adapt to different models of LVDT or different application scenarios without manually adjusting the hardware parameters, which greatly improves the versatility and efficiency of the system.

[0095] The above is only an exemplary embodiment of the present disclosure, and the scope of the present disclosure cannot be limited thereto. That is, any equivalent changes and modifications made according to the teachings of the present disclosure are still within the scope of the present disclosure. After considering the specification and practicing the disclosure here, those skilled in the art will easily think of other embodiments of the present disclosure. This application is intended to cover any modification, use or adaptation of the present disclosure, which follows the general principles of the present disclosure and includes common knowledge or customary technical means in the technical field not recorded in the present disclosure. The description and examples are only regarded as exemplary, and the scope and spirit of the present disclosure are defined by the claims.

Claims

1. A transformer-type differential signal acquisition system, characterized in that: The system includes: a switching power supply module, an input module, an operation circuit, an analog-to-digital conversion module, a CPU processing module, an output module and a communication module; The switching power supply module is used to supply power to the operation circuit, the analog-to-digital conversion module, the CPU processing module and the communication module; The input module is used to collect the feedback signal of the linear variable differential transformer; The operation circuit is used to rectify the feedback signal, perform differential processing and filtering on the rectified feedback signal to obtain a differential filtered signal, and amplify the differential filtered signal after adding a preset bias voltage to obtain an amplified signal; The analog-to-digital conversion module is used to convert the amplified signal into a digital signal, and send the digital signal to the CPU processing module through an isolation chip; The CPU processing module is used to receive the digital signal, process the digital signal, generate a control signal, and send the control signal to the output module and the communication module; The output module is used to generate current according to the control signal; The communication module is used to send the control signal to a host computer through a communication interface, so that the host computer calibrates the linear variable differential transformer.

2. The transformer type differential signal acquisition system according to claim 1, characterized in that: The CPU processing module is in communication connection with the EEPROM chip storage module via a digital bus, and the EEPROM chip storage module is used to store characteristic parameters and calibration data of the linear variable differential transformer.

3. The transformer type differential signal acquisition system according to claim 2, characterized in that: The CPU processing module is also used to read the characteristic parameters and the calibration data in the EEPROM chip storage module, and calibrate and convert the digital signal according to the characteristic parameters and the calibration data to obtain a displacement value corresponding to the actual displacement of the linear variable differential transformer.

4. The transformer type differential signal acquisition system according to claim 3, characterized in that: The CPU processing module is further used to generate the control signal according to the displacement value, and send the control signal to the output module and the communication module.

5. The transformer type differential signal acquisition system according to claim 1, characterized in that: The external interface of the communication module is connected to the base plate through a 64-core socket with long and short pins and a 32-core socket, and then connected to the communication, calibration and output functions of the host computer through the wiring terminals on the base plate.

6. The transformer type differential signal acquisition system according to claim 1, characterized in that: The system also includes a programmer; wherein, The programmer is connected to the CPU processing module via a programming interface and is used for programming and debugging the CPU processing module.

7. The transformer type differential signal acquisition system according to claim 1, characterized in that: The CPU processing module adopts a high-stability and high-speed single-chip microcomputer, which is connected to the communication module through a digital bus, and the CPU processing module is connected to an external programmer through telecommunications.

8. A transformer-type differential signal acquisition method, characterized in that: The method comprises: Collecting feedback signals of linear variable differential transformers; The feedback signal is rectified, the rectified feedback signal is differentially processed and filtered to obtain a differential filtered signal, and the differential filtered signal is amplified after adding a preset bias voltage to obtain an amplified signal; converting the amplified signal into a digital signal; Processing the digital signal to generate a control signal; A current is generated according to the control signal, and the control signal is sent to a host computer through a communication interface, so that the host computer calibrates the linear variable differential transformer.

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