High-precision pressure transmitter and pressure detection system

Abstract

The utility model relates to the technical field of pressure transmitters, in particular to a high-precision pressure transmitter and a pressure detection system, which comprise a pressure core body, a pressure signal processing module, a microcontroller and a DDS (Direct Digital Synthesizer) module, and the input end of the DDS module is connected with the microcontroller; the output end of the pressure core body is connected with the pressure signal processing module, and the pressure signal processing module is connected with the microcontroller; an external power supply is electrically connected with the pressure signal processing module, the microcontroller and the DDS module. According to the high-precision pressure transmitter, a DDS chip controlled by 28-bit frequency of the DDS module is adopted to generate a high-precision and high-stability excitation signal, and the linearity of the pressure transmitter is improved through synchronous sampling of the DDS module and an ADC of the pressure signal processing module in combination with on-chip digital calibration logic.

Description

Technical Field

[0001] This application relates to the field of pressure transmitter technology, and in particular to a high-precision pressure transmitter and pressure detection system. Background Technology

[0002] In fields such as industrial automation, aerospace, and medical equipment, the demand for high-precision measurement of pressure transmitters is growing. To meet the industrial measurement needs of pressure transmitters with an accuracy of 0.05% of full scale (FS) and a resolution below 0.05%, existing high-precision pressure transmitters mainly rely on high-performance ARM processors or FPGAs to achieve high-resolution digital signal processing. However, the ARM+FPGA architecture requires complex embedded software development and hardware logic design, resulting in long development cycles, high difficulty, and high cost of the chips and their components. High-frequency operations also lead to increased power consumption.

[0003] In the existing technology, traditional pressure transmitters mostly use analog oscillation circuits or PLLs to generate excitation signals, but this method has poor frequency stability and is difficult to meet the 0.05% accuracy requirement. Utility Model Content

[0004] To address the aforementioned issues, this application provides a high-precision pressure transmitter and detection system. By synchronously sampling the DDS module and the ADC of the pressure signal processing module, combined with on-chip digital calibration logic, the linearity can be improved to within ±0.05%FS.

[0005] To achieve the objectives of this utility model, this application provides the following technical solution:

[0006] In a first aspect, this application provides a high-precision pressure transmitter, comprising: a pressure core, a pressure signal processing module, and a microcontroller, wherein an input terminal of the pressure core is connected to a DDS module, and an input terminal of the DDS module is connected to the microcontroller; the output terminal of the pressure core is connected to the pressure signal processing module, and the pressure signal processing module is connected to the microcontroller;

[0007] An external power supply is electrically connected to the pressure signal processing module, the microcontroller, and the DDS module, respectively.

[0008] In one possible implementation, the DDS module uses an AD9833 chip, and the pressure core uses an MCS (Metals Coalesce System) core.

[0009] In one possible implementation, the signal processing module employs a JHM1203 chip.

[0010] In one possible implementation, the microcontroller uses an STM32 chip.

[0011] In one possible implementation, the external power supply DC (direct current) system supplies power to the pressure signal processing module, the microcontroller, and the DDS module via a DC-DC converter and an LDO (Low Dropout Regulator).

[0012] In one possible implementation, the microcontroller is connected to the display module, and the microcontroller outputs the pressure value to the display module for display via IIC serial communication; at the same time, the DC power supply system is electrically connected to the display module to supply power to the display module.

[0013] Secondly, this application provides a pressure detection system, including the aforementioned high-precision pressure transmitter.

[0014] The high-precision pressure transmitter provided in this application uses a DDS chip with 28-bit frequency control of the DDS module to generate a high-precision and high-stability excitation signal. Through synchronous sampling of the DDS module and the ADC of the pressure signal processing module, combined with on-chip digital calibration logic, the linearity of the pressure transmitter detection can be improved, achieving 0.05% accuracy on a low-frequency MCU. At the same time, the programmable characteristics of the DDS are used to adjust the excitation frequency in real time to compensate for the nonlinear error of the pressure core. Attached Figure Description

[0015] The accompanying drawings are provided to further understand this application and form part of the specification. They are used together with the embodiments of this application to explain this application and do not constitute a limitation thereof.

[0016] Figure 1 This is a schematic diagram of the structure of a high-precision pressure transmitter provided in an embodiment of this application;

[0017] Figure 2 A schematic diagram of a principle of an embodiment of the DC power supply system for a high-precision pressure transmitter provided in this application;

[0018] Figure 3 A schematic diagram of a principle of an embodiment of the pressure signal processing module of the high-precision pressure transmitter provided in this application;

[0019] Figure 4 A schematic diagram of one embodiment of the microcontroller for the high-precision pressure transmitter provided in this application;

[0020] Figure 5A schematic diagram of one embodiment of the DDS module of the high-precision pressure transmitter provided in this application;

[0021] Figure 6 This is a schematic diagram of the signal processing flow of a high-precision pressure transmitter provided in an embodiment of this application. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0023] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature; in the description of this application, unless otherwise stated, "multiple" means two or more.

[0024] High-precision pressure transmitters (such as 0.05%FS) typically rely on high-performance ARM or FPGA to achieve high-speed ADC data acquisition (≥24 bits, 100kSPS or more), complex digital signal processing (such as FFT, digital phase-locked loop), and high-resolution frequency / digital conversion; however, such chips are expensive and require high-speed clocks and peripheral circuits. The architecture requires complex embedded software development and hardware logic design, resulting in long development cycles and high difficulty.

[0025] To solve the above-mentioned technical problems, the present invention proposes the following technical solutions and corresponding embodiments.

[0026] The following is combined Figures 1 to 6 The embodiments shown illustrate the technical solution of the present invention.

[0027] refer to Figure 1 The diagram shown is a structural schematic of the high-precision pressure transmitter of this application. The pressure transmitter includes a pressure core, a pressure signal processing module, a microcontroller, and a DDS (Direct Digital Synthesizer) module. The input terminal of the DDS module is connected to the microcontroller. The output terminal of the pressure core is connected to the pressure signal processing module, which is connected to the microcontroller. A DC power supply system is electrically connected to the pressure signal processing module, the microcontroller, and the DDS module, respectively.

[0028] Reference Figure 2 As shown, the DC power supply system in this application refers to a DC to DC conversion system, including 15VDC to 5VDC and 5VDC to 3.3VDC. Here, the use of the DC power supply system helps simplify the power supply circuit, shorten the development cycle, and achieve optimal performance indicators.

[0029] In the embodiments of this application, reference is made to Figure 3 As shown, the pressure signal processing module includes a high-precision signal conditioning chip designed for differential signals. This chip integrates a pre-amplifier (PGA), a 24-bit ADC (Analog-to-Digital Converter), a temperature sensor, a digital processor, and memory. The high-precision signal conditioning chip outputs data to the microcontroller via IIC serial communication. During the pressure signal processing stage within the module, the ADC converts the analog signal acquired by the pressure core into digital code and transmits it to the digital processor via IIC serial communication. The digital processor dynamically adjusts the pre-amplifier PGA gain based on the input signal strength. The digital processor performs linearization calibration on the original pressure signal, and simultaneously, the temperature sensor inputs temperature data to the digital processor, executing a temperature compensation algorithm to correct temperature drift errors in the pressure measurement. Here, during system initialization or calibration, the microcontroller sends address commands via the bus to read calibration parameters from memory or write new configuration parameters such as range adjustment values ​​to ensure the accuracy of the pressure signal processing.

[0030] For example, the high-precision signal conditioning chip may be JHM1203.

[0031] In the embodiments of this application, reference is made to Figure 5 As shown, the DDS module uses the AD9833 chip to convert analog signals into PWM digital frequency outputs. The AD9833 frequency register is 28-bit, with accuracies of 0.004Hz and 0.1Hz for main clock frequencies of 1-25MHz. It has three standard serial interfaces, each with a maximum operating frequency of 40MHz, making it easily compatible with various mainstream MCUs. The AD9833 operates within a voltage range of 2.3V-5.5V and exhibits strong resistance to external interference. Furthermore, the AD9833 chip integrates frequency synthesis logic, reducing the workload of FPGA timing design and shortening the development cycle to within one month.

[0032] In the embodiments of this application, reference is made to Figure 4As shown, the microcontroller communicates with the pressure signal acquisition and processing module via the IIC serial port to exchange sampled data, and simultaneously communicates with the AD9833 (ADI) chip to control the adjustment and output of the digital frequency. For example, an STM32 microcontroller is used. However, other existing chip models can also be used in this embodiment, depending on the required processing accuracy and functionality; these will not be listed here. The microcontroller can also be a DSP processor, an ARM processor, or a microcontroller. This microcontroller can perform filtering and fitting operations on the digital pressure signal, and may also have other processing functions such as circuit fault self-diagnosis; specific limitations are not specified here.

[0033] In this embodiment, the pressure core uses an MCS (Metals Coalesce System) core, which can reliably operate in environments ranging from -45 degrees Celsius to 125 degrees Celsius. The specific structure of the MCS pressure core can be found in Chinese Patent Application No. 202410005995.4.

[0034] In one feasible implementation, the output of the microcontroller is connected to a display module, which receives and displays pressure values ​​from the microcontroller via IIC serial communication. Here, the DC power supply system is electrically connected to the display module to provide power. Exemplarily, the display module is a display screen.

[0035] The high-precision pressure transmitter of this application uses a 28-bit frequency-controlled DDS chip in the DDS module to generate a high-precision and high-stability excitation signal. Through synchronous sampling of the DDS module and the ADC of the pressure signal processing module, combined with on-chip digital calibration logic, the linearity of the pressure transmitter is improved, achieving 0.05% accuracy on a low-frequency MCU. At the same time, by utilizing the programmable characteristics of DDS, the excitation frequency can be adjusted in real time to compensate for the nonlinear error of the pressure core.

[0036] Here, based on the foregoing embodiments, this application provides a signal processing method for a high-precision pressure transmitter; see reference Figure 6 As shown, the specific steps include: after the system starts and the driver is initialized, the STM32 continuously checks whether the serial port receives data (pressure signal) output by the pressure signal processing module through IIC serial communication; after detecting data (pressure signal) from the serial port, the STM32 drives the AD9833 to output a digital frequency corresponding to the pressure signal through the serial communication SPI interface to drive the pressure core, and at the same time, the AD9833 output is divided and used as the sampling clock of the ADC of the pressure signal processing module.

[0037] After the STM32 fails to detect data from the serial port, it periodically obtains the pressure value (data) from the pressure signal processing module and drives the AD9833 to output a digital frequency corresponding to the pressure signal through the serial communication SPI interface to drive the pressure core based on the pressure value.

[0038] Based on the foregoing embodiments, this application also provides a pressure detection system, including the high-precision pressure transmitter described above, which is used to detect the pressure value corresponding to the target object in real time.

[0039] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram or flowchart, and combinations of blocks in a block diagram or flowchart, may be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0040] It should be noted that although several modules or units of the device for performing actions have been mentioned in the detailed description above, this division is not mandatory. In fact, according to embodiments of the present invention, the features and functions of two or more modules or units described above can be embodied in one module or unit. Conversely, the features and functions of one module or unit described above can be further divided and embodied by multiple modules or units.

[0041] Through the above description of the embodiments, those skilled in the art will readily understand that the exemplary embodiments described herein can be implemented by software or by combining software with necessary hardware. Therefore, the technical solutions according to the embodiments of the present invention can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (such as a CD-ROM, USB flash drive, portable hard drive, etc.) or on a network, including several instructions to cause a computing device (such as a personal computer, server, touch terminal, or network device, etc.) to execute the method according to the embodiments of the present invention.

[0042] In the embodiments provided in this application, it should be understood that the disclosed systems, modules, and methods can be implemented in other ways. For example, the module embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces, or indirect coupling or communication connection between modules or units, and may be electrical, mechanical, or other forms.

[0043] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit it. This application is not limited to the exact structures described above and illustrated in the accompanying drawings, and it should not be considered that the specific implementation of this application is limited to these descriptions. For those skilled in the art, various changes and modifications made without departing from the concept of this application should be considered to fall within the protection scope of this application.

Claims

1. A high-precision pressure transmitter, characterized in that, include: The system comprises a pressure core, a pressure signal processing module, a microcontroller, and a DDS module. The input terminal of the pressure core is connected to the DDS module, and the input terminal of the DDS module is connected to the microcontroller. The output terminal of the pressure core is connected to the pressure signal processing module, and the pressure signal processing module is connected to the microcontroller. The DC power supply system is electrically connected to the pressure signal processing module, the microcontroller, and the DDS module, respectively.

2. The high-precision pressure transmitter according to claim 1, characterized in that, The DDS module uses the AD9833 chip, and the pressure core uses a multi-metal fusion system core.

3. The high-precision pressure transmitter according to claim 1, characterized in that, The signal processing module uses the JHM1203 chip.

4. The high-precision pressure transmitter according to claim 1, characterized in that, The microcontroller uses an STM32 chip.

5. The high-precision pressure transmitter according to any one of claims 1 to 4, characterized in that, The DC power system supplies power to the pressure signal processing module, the microcontroller, and the DDS module via a DC-DC converter and an LDO linear regulator.

6. The high-precision pressure transmitter according to claim 5, characterized in that, The microcontroller is connected to the display module, which is used to display the pressure value. The DC power supply system is electrically connected to the display module and is used to supply power to the display module.

7. A pressure detection system, characterized in that, The high-precision pressure transmitter described in any one of claims 1 to 6 above.

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