Intelligent acquisition controller for valves

Abstract

The application belongs to the technical field of industrial automation control, and particularly relates to an intelligent acquisition controller for valves. The controller comprises a hardware body and matched software, and the hardware body integrates a main control, a signal acquisition, an analog output, a multi-path power supply, a multi-mode communication and a man-machine interaction module. The signal acquisition module is provided with 3 4-20mA channels and 2 PT1000 channels, realizing high-precision synchronous acquisition of pressure, temperature and valve position. The multi-path power supply module supports mains, DC and battery input, and intelligently schedules an NB-IoT or 4G communication module according to the power supply state to optimize power consumption. The valve intelligent regulation and control unit calculates a theoretical flow coefficient based on real-time pressure difference, target flow and medium density, and automatically adjusts the valve opening through table lookup matching and closed-loop iteration algorithm. The application solves the problems of few acquisition channels, single power supply, inflexible communication and low regulation and control precision of the existing controller, and realizes intelligent, high-precision closed-loop control and remote operation and maintenance of the valve.

Description

Technical Field

[0001] This invention relates to the field of industrial automation control technology, and more specifically to an intelligent data acquisition controller for valves. Background Technology

[0002] In industrial pipeline systems, valves supplying water and heating fluids require real-time monitoring of pressures before and after the valves, as well as the temperature of the supplied and returned water. Simultaneously, the valve actuator opening must be automatically adjusted based on target flow rate and pressure difference to achieve stable fluid pressure and flow control. With the rapid development of smart heating and intelligent water systems, higher demands are being placed on valve controllers in terms of functional integration, data acquisition accuracy, power supply adaptability, communication flexibility, and the level of intelligent control.

[0003] Existing valve controllers still suffer from several technical defects in practical applications: (I) Insufficient number of acquisition channels and limited signal types. Existing valve controllers generally only have two 4-20mA analog acquisition channels, which cannot simultaneously acquire three signals: valve inlet pressure, valve outlet pressure, and actuator position feedback. For example, Chinese invention patent CN121346061A discloses a smart valve that acquires 4-20mA transmitters powered by a power supply, which only has two 4-20mA signal acquisition modules, and the temperature detection module is not specified in terms of its type. Due to the lack of actuator position feedback signal acquisition, the controller cannot obtain the actual valve opening in real time, which restricts the improvement of closed-loop control accuracy. In addition, existing solutions mostly use general-purpose temperature sensors for temperature acquisition, without special configuration for the special needs of industrial pipeline supply and return water temperature detection, resulting in insufficient acquisition accuracy and long-term stability. (II) Limited power supply options and lack of low-power design. Most existing valve controllers only support a single power supply method, such as only supporting 24V DC power supply or only supporting AC mains power supply, which cannot adapt to various power supply conditions such as on-site battery offline monitoring, industrial DC power supply, and AC mains power. Especially for valve monitoring scenarios in outdoor areas without electricity, the lack of low-power battery power supply solutions results in short equipment battery life, frequent maintenance, and difficulty in meeting the needs of long-term offline monitoring. (III) Fixed communication methods and lack of local debugging means. The communication methods of existing valve controllers are mostly fixed configurations, supporting only single wired 485 communication or single wireless communication, and cannot flexibly switch between different communication methods such as Wi-Fi, 4G, and NB-IoT according to field requirements. Especially in battery-powered scenarios, there is a lack of switching mechanisms adapted to low-power narrowband communication, making it difficult to balance battery life and communication requirements. At the same time, existing products generally lack Bluetooth local debugging functions, and on-site network configuration and parameter modification must rely on host computers or dedicated debugging tools, resulting in low operation and maintenance efficiency and high debugging costs. (IV) Simple valve control logic and lack of intelligent adjustment based on flow coefficient. The adjustment logic of existing valve controllers mostly adopts simple open-loop output or conventional PID control, which only supports driving the actuator according to a fixed opening degree and cannot make precise adjustments according to the actual flow capacity of the valve. Chinese invention patent CN121957160A discloses a flow intelligent control method based on differential pressure measurement. This method calculates the theoretical flow capacity coefficient based on the valve position signal and the valve's inherent flow characteristic curve, and then corrects for the actual flow capacity coefficient using operating parameters. However, this method does not involve pre-storing and matching the valve's inherent Kv data table, nor does it provide a complete adjustment process for automatic opening conversion and closed-loop iterative fine-tuning based on the lookup results. In practical applications, it still relies on repeated trial adjustments, and the control accuracy and adjustment efficiency need further improvement. (V) Insufficient protection and human-machine interaction. Existing valve controllers generally lack comprehensive hardware protection design, with weak waterproof, lightning protection, isolation, and anti-interference capabilities, making it difficult to operate stably for long periods in a wide-temperature industrial environment of -40~85℃.Regarding human-machine interaction, there is a lack of local interaction methods such as status indicator lights, dedicated buttons for power distribution, and external display screen interfaces, making it impossible to intuitively view equipment status and real-time collected data. (vi) Lack of access control for operations. On-site personnel can arbitrarily modify parameters and adjust valves, posing a production safety hazard, and there is no password unlocking and reset mechanism.

[0004] In summary, there is an urgent need for a valve intelligent data acquisition controller that features high-precision acquisition of multiple signals, compatibility with multiple power supplies, modularity and multi-communication, built-in local Bluetooth debugging, automatic valve adjustment with flow coefficient algorithm, hierarchical access control, and high protection with wide temperature applicability. Summary of the Invention

[0005] This invention provides an intelligent data acquisition controller for valves, aiming to solve the technical defects of existing valve controllers, such as insufficient data acquisition channels, single power supply scheme, fixed communication method, simple adjustment logic, insufficient protection and interaction, and lack of operation permission control.

[0006] To solve the above-mentioned technical problems, the present invention provides an intelligent data acquisition controller for valves, including a controller hardware body and supporting debugging and control software; The controller hardware includes a main control processing module, a signal acquisition module, an analog output drive module, a multi-channel power supply module, a multi-mode communication module, and a human-machine interaction module. The signal acquisition module is equipped with an analog input channel and a temperature acquisition channel, which are used to acquire the pressure before the valve, the pressure after the valve, the actuator feedback signal, and the supply and return water temperature. The analog output drive module is equipped with a conversion output channel for outputting analog signals to drive the valve actuator; The multi-power supply module integrates three power supplies: battery input, DC input, and AC input. The DC input and the AC input take priority over the battery input. When only the battery input is powered, the whole machine switches to a low-power mode. The multimode communication module includes a short-range wireless communication module, a slot-type replaceable cellular communication module, and a wired bus interface. The accompanying debugging and control software runs on a mobile terminal and includes a network distribution unit, a parameter configuration unit, and a valve intelligent control unit. The network distribution unit is used for Bluetooth connection to complete Wi-Fi network distribution and server address configuration. The parameter configuration unit is used to read and modify the controller's operating parameters, with advanced configuration functions requiring password verification. The valve intelligent control unit calculates the pressure difference based on the collected inlet and outlet pressures, calculates the flow coefficient according to the target flow rate and medium density, retrieves the valve data table to match the target opening degree closest to the flow coefficient, and outputs a control signal to the actuator. After adjustment, the pressure difference is re-collected, the theoretical flow coefficient is recalculated, and the opening degree is re-matched by looking up the table. If the deviation between the matched opening degree and the current opening degree is greater than a preset threshold, the adjustment continues; if the deviation is less than the preset threshold, the iteration stops.

[0007] Furthermore, the analog input channels are three 4-20mA channels, which respectively acquire the valve inlet pressure, valve outlet pressure, and actuator position feedback signal, with an acquisition accuracy of no less than 16 effective bits for the ADC; the temperature acquisition channels are two PT1000 RTD channels, which respectively acquire the supply water temperature and return water temperature, with an acquisition accuracy of no less than 14 effective bits for the ADC; the conversion output channels are DAC digital-to-analog conversion channels, outputting a 4-20mA current signal or a 0-10V voltage signal, with a full-range linearity of analog output better than 0.15%.

[0008] Furthermore, the multi-channel power supply module has a lithium battery as the battery input, a wide-voltage power supply as the DC input, and a mains power supply as the AC input, and is equipped with a wind power or solar power supply interface; the main control processing module is configured to: when it detects that the battery input is providing power, if the cellular communication module is an NB-IoT module, enable it to communicate; if it is a 4G module, disable cellular communication or issue a low battery warning.

[0009] Furthermore, the human-machine interaction module includes a three-color indicator light with integrated button function, an independent power indicator light, an independent network configuration button, and an external display interface; when the network configuration button is pressed, Bluetooth network configuration mode is enabled, and when pressed again, Bluetooth is disabled; the three-color indicator light indicates normal operation in green, low power in yellow, and device malfunction in red.

[0010] Furthermore, the valve intelligent control unit automatically adjusts based on the flow coefficient Kv algorithm, and its adjustment process includes: Step 1: Obtain the real-time inlet pressure P1 and outlet pressure P2, and calculate the pressure difference. =P1-P2; Step 2: Based on the target traffic and medium density According to the formula Calculate the theoretical flow coefficient; Step 3: Retrieve the locally stored valve Kv data table and match the valve opening corresponding to the Kv value that is closest to the theoretical flow coefficient; Step 4: Convert the valve opening degree into a 4-20mA or 0-10V analog control signal, and output it to the actuator through the conversion output channel; Step 5: After adjustment, re-collect the differential pressure, recalculate the theoretical Kv value, and re-match the opening degree by looking up the table; if the deviation between the matched opening degree and the current opening degree is greater than the preset threshold, continue adjustment; if the deviation is less than the preset threshold, stop iteration. Step 6: The valve intelligent control unit also includes a percentage closed-loop fine-tuning mode. In this mode, the drive signal is output according to the opening percentage. The step size of each iteration is a preset step size. The iteration is terminated when the deviation between the actual opening and the target opening is less than the preset threshold.

[0011] Furthermore, the main control processing module integrates a non-volatile storage unit to save user configuration parameters, valve Kv data tables, and opening-flow comparison tables; the controller hardware body also has a hardware protection circuit, which adopts diaphragm isolation and frequency cutoff anti-interference design, and integrates waterproof, lightning protection, current limiting, voltage limiting and reverse connection protection, and the whole machine has a wide operating temperature range.

[0012] Furthermore, the supporting debugging and control software also includes a permission management unit, which sets an administrator password and a manufacturer unlock password; the parameter configuration unit is divided into basic configuration and advanced configuration, and the advanced configuration function requires verification by the administrator password; the start-up and modification of the control parameters of the valve intelligent control unit also require verification by the administrator password; the manufacturer unlock password is used to reset the administrator password if it is forgotten.

[0013] Furthermore, the DAC digital-to-analog conversion channel employs a multi-point matrix interpolation calibration method for linearity correction. This calibration method includes: acquiring actual output values ​​at multiple calibration points within the DAC output range; establishing a piecewise interpolation function between the output error and the digital input code to form an error compensation matrix; repeatedly calibrating at multiple temperature points within the operating temperature range to obtain the error compensation matrix at each temperature point, and constructing a temperature-error two-dimensional interpolation table; and retrieving the two-dimensional interpolation table based on the current operating temperature measured by the onboard temperature sensor during real-time control for error compensation.

[0014] Furthermore, the controller hardware also integrates a current spectrum analysis module, coupled with the output circuit of the analog output drive module, for acquiring drive current signals of the actuator at preset frequency bands under different opening degrees, extracting the spectral feature vectors corresponding to each opening point, including fundamental frequency amplitude, second harmonic amplitude, third harmonic amplitude, and spectral energy distribution characteristics, and storing them in association with opening value and differential pressure value to construct a typical operating condition current spectrum fingerprint library; the main control processing module acquires the current spectrum in real time during operation and matches and compares it with the current spectrum fingerprint library, and generates a fault warning signal when the deviation between the real-time spectrum and the spectral features of the corresponding operating condition in the fingerprint library exceeds a preset threshold.

[0015] Furthermore, the PCB board of the signal acquisition module is provided with a flexible thin film shielding cavity, which is formed by a flexible insulating substrate and a conductive shielding layer covering at least one side thereof, and the analog signal processing circuit of the signal acquisition module is arranged inside the flexible thin film shielding cavity. Laser-etched heat dissipation windows are provided on the conductive shielding layer. The heat dissipation windows consist of multiple openings that penetrate the conductive shielding layer. The opening width and spacing are preset. The heat dissipation windows are optimized so that the shielding cavity can simultaneously meet the following requirements within a wide temperature range: the maximum operating temperature of the analog signal processing circuit does not exceed 85℃; and the shielding effectiveness against electromagnetic interference in the 2kHz~20kHz frequency band is not less than 60dB.

[0016] Compared with the prior art, the present invention has the following beneficial effects: First, this invention sets up three 4-20mA channels and two PT1000 channels, which can simultaneously collect the pressure before and after the valve, the actuator feedback, and the supply and return water temperatures. Combined with a high-precision ADC and digital filtering algorithm, it effectively suppresses on-site noise interference, providing a complete, stable, and reliable real-time data foundation for accurate calculation of the Kv flow coefficient and high-precision closed-loop control of the valve.

[0017] Secondly, this invention integrates three independent power supply inputs: lithium battery, wide-voltage DC, and AC mains power. DC and AC inputs take priority over battery input. When external power sources are unavailable, it automatically switches to battery input and activates a low-power mode. In battery-powered mode, only NB-IoT module communication is enabled, minimizing power consumption. This three-way adaptive power supply architecture allows the device to adapt to various operating conditions, including offline monitoring, fixed equipment rooms, outdoor areas without electricity, and wind / solar power supply, significantly improving on-site deployment flexibility.

[0018] Third, this invention comes standard with a Wi-Fi and Bluetooth combination module for local network configuration and debugging, and uses a slot-type replaceable 4G / NB-IoT module for on-demand selection, with a 485 bus interface for connecting to local industrial control. In battery-powered mode, only the NB-IoT module is used for communication, ensuring remote data transmission capabilities while minimizing overall power consumption. The slot-type design allows for on-site replacement and upgrades of the communication module without replacing the entire device, significantly reducing maintenance and upgrade costs.

[0019] Fourth, this invention pre-stores a valve Kv data table and an opening-flow rate comparison table in a local non-volatile storage unit. Based on the real-time collected inlet and outlet pressures, it calculates the pressure difference and the theoretical flow coefficient according to the target flow rate and medium density. It then retrieves the Kv data table to match the valve opening corresponding to the Kv value closest to the theoretical flow coefficient, converts it into an analog signal to drive the actuator, and automatically iterates and corrects the pressure difference until the deviation is less than the preset threshold after adjustment. At the same time, it provides a percentage closed-loop fine-tuning mode for precise adjustment according to a preset step size. The entire process does not require repeated manual trial and error, which significantly improves the intelligence and accuracy of valve adjustment.

[0020] Fifth, this invention uses multiple calibration points within the DAC output range to collect actual output values, establishes a piecewise interpolation function between the output error and the digital input code to form an error compensation matrix; repeatedly calibrates at multiple temperature points within the operating temperature range to obtain the error compensation matrix at each temperature point, and constructs a temperature-error two-dimensional interpolation table; in real-time control, the table is looked up for compensation based on the current operating temperature, so that the DAC output linearity is better than 0.15%, and high-precision linear output can be maintained throughout the entire temperature range.

[0021] Sixth, this invention integrates a current spectrum analysis module to collect drive current signals of the actuator in preset frequency bands at different opening degrees, extract the fundamental frequency amplitude, second harmonic amplitude, third harmonic amplitude, and spectral energy distribution characteristics, and associate and store them with the opening degree value and differential pressure value to construct a typical operating condition current spectrum fingerprint library; during operation, the current spectrum is collected in real time and matched and compared with the current spectrum fingerprint library, and a fault warning signal is generated when the deviation exceeds the threshold, which can identify the early abnormal trend of the actuator, realize early fault warning, and effectively avoid sudden shutdown.

[0022] Seventh, the present invention uses a flexible insulating substrate and a conductive shielding layer to form a shielding cavity, and arranges the analog signal processing circuit inside the shielding cavity to effectively suppress external electromagnetic interference; laser-etched heat dissipation windows are opened on the conductive shielding layer, and the opening width and spacing are optimized to ensure that the shielding cavity meets the heat dissipation requirements and electromagnetic shielding with a preset frequency band not lower than the preset shielding effectiveness in a wide temperature operating range, ensuring the signal-to-noise ratio of the analog channel while ensuring the long-term stable operation of the equipment over a wide temperature range.

[0023] Eighth, this invention features integrated button functions with a three-color indicator light (green for normal, yellow for low battery, and red for fault), an independent power indicator light, and an independent network pairing button for one-click Bluetooth network pairing. An external display interface shows the device ID, network connection method, temperature and pressure data, and actuator opening in real time. The accompanying software has two levels of access control: an administrator password and a manufacturer's unlock password. Advanced configurations require administrator verification, and the manufacturer's unlock password is used to reset the password if forgotten by the administrator. It also integrates diaphragm isolation, frequency cutoff interference suppression, waterproofing, lightning protection, current limiting, voltage limiting, and reverse connection protection circuits, allowing the entire unit to operate stably over a wide temperature range for extended periods. This facilitates on-site maintenance and debugging while effectively preventing accidents caused by unauthorized personnel.

[0024] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description and drawings.

[0025] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0026] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the printed circuit board (PCB) layout of the controller hardware body of the intelligent data acquisition controller for valves of the present invention; Figure 2 A schematic diagram of the structure of an intelligent data acquisition controller for valves; Figure 3 This is a schematic diagram of the automatic adjustment process of the valve intelligent control unit of the present invention based on the flow coefficient Kv algorithm. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0028] In this invention, the term "preset" describes configurable parameters that can be configured by the user through the accompanying debugging and control software, or preset and stored in the non-volatile storage unit at the factory. "Wide temperature operating range" refers to a temperature range from -40°C to 85°C.

[0029] Example 1: As Figure 2 As shown, a smart data acquisition controller for valves includes a controller hardware body and supporting debugging and control software.

[0030] The controller hardware mainly consists of a main control processing module, a signal acquisition module, an analog output driver module, a multi-channel power supply module, a multi-mode communication module, and a human-machine interface module. The main control processing module uses an industrial-grade ARM Cortex-M4 microcontroller as its core processor (such as the STM32F407 series or LPC4088 series), operating at 120MHz, with a built-in floating-point unit. It performs all logical processing tasks, including data acquisition, filtering calculations, communication protocol stack operation, flow coefficient Kv algorithm calculations, and control signal output. The signal acquisition module has analog input channels and temperature acquisition channels. The analog input channels are used to connect to external pressure transmitters and actuator position feedback sensors, while the temperature acquisition channel is used to connect to a PT1000 RTD temperature sensor. The analog output driver module has a conversion output channel used to convert the control quantities calculated by the main control processing module into analog signals to drive the valve actuator.

[0031] The multi-power supply module integrates three power supply interfaces: battery input, DC input, and AC input. The module contains a power supply priority determination circuit. When a valid external power source is connected to either the DC or AC input, the circuit automatically switches to the primary power source, prioritizing power to the entire unit. When neither the DC nor AC input has a valid power source, the circuit automatically switches to battery input and simultaneously sends a low-power mode enable signal to the main control module, causing the entire unit to switch to low-power operation.

[0032] The multi-mode communication module includes a short-range wireless communication module, a slot-type replaceable cellular communication module, and a wired bus interface. The short-range wireless communication module enables short-range communication with mobile terminals, supporting device network configuration, parameter configuration, and data reading. The slot-type replaceable cellular communication module uses standard Mini PCIe or LGA slots, allowing users to select different cellular communication modules based on their field communication needs. The wired bus interface is used for wired communication connections with host computers or industrial control systems.

[0033] The accompanying debugging and control software runs on a mobile terminal (such as a smartphone or tablet), which establishes a communication connection with the controller hardware via Bluetooth or Wi-Fi. The software includes a network distribution unit, a parameter configuration unit, and a valve intelligent control unit. The network distribution unit is used to complete the Wi-Fi network distribution and backend server address configuration of the controller hardware via Bluetooth. The parameter configuration unit is used to read and modify the controller's operating parameters, and is divided into basic configuration and advanced configuration, with the advanced configuration function requiring password verification. The valve intelligent control unit is used to realize automatic valve regulation and control based on the flow coefficient Kv. The valve intelligent control unit performs the following adjustment process: acquiring real-time inlet and outlet pressures and calculating the pressure difference; calculating the theoretical flow coefficient based on the target flow rate, pressure difference, and medium density; retrieving the locally stored valve Kv data table and matching the valve opening corresponding to the Kv value closest to the theoretical flow coefficient; converting the valve opening into an analog control signal and outputting it to the actuator; after adjustment, re-acquiring the pressure difference, recalculating the theoretical Kv value, and re-matching the opening by looking up the table; if the deviation between the matched opening and the current opening is greater than a preset threshold, the adjustment continues; if the deviation is less than the preset threshold, the iteration stops.

[0034] The controller hardware is also equipped with multiple external wiring terminals, including analog input terminals, temperature acquisition terminals, analog output terminals, communication terminals, and power supply terminals. Each terminal uses a pluggable terminal block, which facilitates quick wiring and replacement on site.

[0035] like Figure 1 The diagram shown is a schematic of the printed circuit board (PCB) layout of the controller hardware of the intelligent data acquisition controller for valves described in this invention. This PCB highly integrates all the core functional modules required to implement the technical solution of this invention.

[0036] The upper left corner of the circuit board houses the physical interfaces for multiple power supply modules, including a DC wide-voltage input terminal (P2) labeled "9-36V" and a lithium-ion battery input interface labeled "Battery," enabling compatibility and automatic switching between external DC power and internal battery power supply. Near the power input terminals, a hardware protection circuit composed of inductors (such as CD104) and TVS diodes is installed to provide lightning protection, reverse connection protection, and surge protection for the entire device.

[0037] The upper right corner of the circuit board features a terminal block labeled "3 inputs + 1 output." This terminal connects to the onboard high-precision analog-to-digital converter (ADC) and digital-to-analog converter (DAC) chips (such as U12), together forming the signal acquisition module and analog output drive module. Specifically, the three analog input channels are used to acquire the valve inlet pressure, valve outlet pressure, and actuator position feedback signals, respectively; the two PT1000 RTD acquisition channels are used to acquire the supply and return water temperatures; and the one DAC output channel is used to generate a 4-20mA or 0-10V analog signal to precisely drive the valve actuator.

[0038] A slot (P9) is located in the center of the bottom of the circuit board. This is a slot-type replaceable cellular communication module interface, which can flexibly insert a 4G or NB-IoT communication module according to field requirements. The independent module area (P3) on its right integrates a Wi-Fi and Bluetooth combination module, providing short-range wireless communication and local debugging functions. In addition, the "485" terminal in the lower right corner of the circuit board forms a wired bus interface for connecting to an RS-485 industrial bus, enabling stable communication with a host computer.

[0039] like Figure 1 As shown in the left-hand area, the circuit board integrates a complete human-machine interface module. This module includes an independent network configuration button (KEY1), a set of three-color status indicator lights (LEDs), and an external display screen interface labeled "Screen". Operators can intuitively understand the equipment status and perform local network configuration operations through the buttons and indicator lights, and can also view the valve's various operating parameters in real time through the external display screen.

[0040] The large integrated circuit chip (U6) located in the center of the circuit board is the main control processing module (MCU) of the entire controller. As the core, it is electrically connected to all the above modules and is responsible for processing the acquired data, parsing the communication protocol, executing the valve adjustment algorithm, and controlling the whole machine.

[0041] Example 2: Multi-channel high-precision signal acquisition and analog output.

[0042] The analog input channels of the signal acquisition module are configured with three (or more) 4-20mA channels. Each 4-20mA channel is connected to an external transmitter: the first 4-20mA channel is connected to a pressure transmitter installed on the upstream pipeline of the valve to acquire the upstream pressure; the second 4-20mA channel is connected to a pressure transmitter installed on the downstream pipeline of the valve to acquire the downstream pressure; and the third 4-20mA channel is connected to a position feedback sensor installed on the valve actuator to acquire the actual opening position feedback signal of the actuator. The signal conditioning circuit of each 4-20mA channel is equipped with a precision sampling resistor (typically 250Ω, accuracy ±0.1%) to convert the 4-20mA current signal into a 1-5V voltage signal before sending it to the analog-to-digital converter (ADC) for digital acquisition. This ADC is a high Σ-Δ type ADC with at least 16 effective bits (e.g., ADS1256 or AD7768 series).

[0043] The signal acquisition module has two (or more) PT1000 resistance temperature detector (RTD) channels for temperature acquisition. The first PT1000 channel connects to a PT1000 platinum RTD temperature sensor installed on the supply water pipe to acquire the supply water temperature; the second PT1000 channel connects to a PT1000 platinum RTD temperature sensor installed on the return water pipe to acquire the return water temperature. Each PT1000 channel uses a three-wire or four-wire connection to eliminate the influence of lead resistance. The resistance value of the PT1000 is converted into a voltage signal by a constant current source (typically 1mA) and then sent to an analog-to-digital converter (ADC) for digital acquisition. This ADC uses a medium-to-high precision Σ-Δ ADC with at least 14 effective bits (e.g., the ADS1248 series).

[0044] The main control processing module performs digital filtering on the acquired signals, including median filtering and arithmetic mean filtering. The median filtering window is set to 5 sampling points to eliminate impulse noise interference. The arithmetic mean filtering window is set to 10 sampling points to smooth random noise. The acquired data after digital filtering is stored in the internal register of the main control processing module for use in the flow coefficient Kv algorithm calculation.

[0045] The analog output driver module uses a DAC (Digital-to-Analog Converter) channel for its output conversion. This DAC is a 12-bit or higher resolution digital-to-analog converter with a mode selection circuit at its output. It can be configured via hardware jumpers or software to output either a 4-20mA current signal or a 0-10V voltage signal. When the current output mode is selected, the DAC's output voltage is converted into a 4-20mA current signal through a V / I conversion circuit to drive the valve actuator. When the voltage output mode is selected, the DAC's output voltage is directly output as a 0-10V voltage signal through a voltage buffer amplifier to drive the valve actuator. After full-temperature-range calibration, the linearity of the DAC's output current is significantly improved across the entire temperature range (see Example 8 for specific calibration methods).

[0046] Example 3: Three-way power supply adaptive switching and multi-mode communication.

[0047] The multi-power supply module integrates three independent power input interfaces. The battery input interface is compatible with lithium batteries, including but not limited to lithium-ion batteries (such as the ER34615 model) and rechargeable lithium-ion batteries (such as the 18650 model), with a nominal voltage range of 3.0V to 9.0V. Typical applications use a single 3.6V lithium-ion battery or two 3.7V lithium-ion batteries connected in series; lithium polymer batteries or other lithium battery packs that meet voltage requirements can also be used. The DC input interface is compatible with a wide-voltage DC power supply, with an input voltage range of 9V to 36V. Typical applications use a 24V DC power supply provided in the industrial field. The AC input interface is compatible with AC mains power, with an input voltage range of 110V to 230V (AC) and a frequency of 50Hz or 60Hz. The multi-power supply module also has a reserved wind or solar power supply interface, allowing for supplemental charging of the lithium batteries via an external wind turbine or solar photovoltaic panel.

[0048] The multi-power supply module internally incorporates a power supply priority determination circuit and a power switching circuit. The power supply priority determination circuit monitors the validity of the DC and AC input voltages in real time. When the detected DC input voltage is greater than 7V or the AC input voltage is greater than 85V, the external power supply is deemed valid. These voltage thresholds are set based on industrial site power supply fluctuations and lithium battery discharge characteristics: 7V DC is higher than the lithium battery discharge termination voltage (generally 6.0V~7.0V), ensuring that the switch to external DC power is completed before the battery voltage drops to a critical value, avoiding power switching oscillations caused by voltage crossovers; 85V AC is the validity point for industrial site mains power supply. Values ​​below this are considered abnormal, and the system switches to backup power. The priority order is: AC input takes precedence over DC input, and DC input takes precedence over battery input. When the AC input is valid, the entire unit is powered by AC; when the AC input is invalid but the DC input is valid, the entire unit is powered by DC; when both AC and DC inputs are invalid, the entire unit automatically switches to battery power.

[0049] In one specific implementation, the power supply priority determination circuit and the power switching circuit operate according to the following logic: when the AC input is valid, the entire device is powered by AC; when the AC input is invalid but the DC input is valid, the entire device is powered by DC; when both the AC and DC inputs are invalid, the entire device automatically switches to battery power. The power switching circuit can be implemented by a combination of a power multiplexer chip and a PMOS switch, or by a logic determination circuit composed of discrete components and a MOSFET switch network, with a switching time of less than 100μs.

[0050] When the device switches to battery power, the power priority determination circuit sends a low-power mode enable signal to the main control processing module. Upon receiving this signal, the main control processing module performs the following low-power operations: shuts down the power supply to the 4G module, completely de-energizing it (because only the NB-IoT module needs to perform low-rate data transmission when powered by battery); switches the Wi-Fi module to sleep mode; extends the acquisition cycle from 20ms in normal mode to 1s in low-power mode; and extends the data upload interval from 1 minute in normal mode to 10 minutes in low-power mode. When powered by battery, the power indicator light only illuminates during network configuration operations or button presses, remaining off at other times.

[0051] To achieve optimal power management and hardware compatibility, the main control processing module is also equipped with a communication scheduling strategy. The main control processing module is configured to monitor the current power supply status and the type of cellular communication module connected in real time: When the main control processing module detects that the entire device is powered by battery input, if it identifies an NB-IoT module connected in the slot, it automatically enables the NB-IoT module for remote data transmission to meet low power requirements; if it identifies a 4G module connected in the slot, due to the high power consumption of the 4G module under battery power, the main control processing module will automatically disable the communication function of the 4G module to protect battery life, and simultaneously trigger a low battery warning mechanism (e.g., controlling the three-color indicator light to illuminate yellow or red, or displaying a pop-up message on the local screen) to remind on-site maintenance personnel to replace it with an NB-IoT module or switch to external DC / AC power supply. When the entire device is powered by DC or AC input, the main control processing module will normally enable the 4G module or NB-IoT module for high-speed or low-power communication according to the DIP switch settings or software configuration.

[0052] Example 4: Human-computer interaction module.

[0053] The human-machine interface module includes a tri-color indicator light with integrated button function, an independent power indicator light, an independent network configuration button, and an external display interface. The tri-color indicator light uses RGB tri-color LEDs or a combination of three independent single-color LEDs (red, yellow, and green). It integrates button function; pressing the backlit button cap of the tri-color indicator light triggers a button signal. The colors of the tri-color indicator light have the following meanings: green when the machine is running normally; yellow when the battery level is below a preset threshold (typically 30% of the remaining capacity); and red when the device malfunctions (such as sensor disconnection, communication abnormality, actuator drive failure, etc.).

[0054] The tri-color indicator light also functions as a lighting control for the external LED display: a short press of the tri-color indicator light button will turn on the external LED display and show device information; if there is no operation within 60 seconds after it is turned on, it will automatically turn off, or a short press of the button again will turn it off immediately.

[0055] The independent network configuration button is a separate physical button. Press and hold this button for 3 seconds to activate the Bluetooth network configuration mode on the main control module. The Bluetooth module will then be discoverable and connectable, indicated by a flashing power indicator. Users can search for and connect to the Bluetooth module using the accompanying debugging and control software on their mobile devices to complete Wi-Fi network configuration and server address configuration. After network configuration is complete, press and hold the button again for 3 seconds to deactivate the Bluetooth network configuration mode.

[0056] The external display interface is a standardized ribbon cable interface (such as an FPC ribbon cable socket) for connecting an external LED display screen. The display screen shows the following information: device ID, current network connection method, network signal strength, current power supply type, user-defined valve name, real-time inlet / outlet pressure, real-time supply / return water temperature, and actuator opening percentage.

[0057] Example 5: Automatic valve regulation based on the flow coefficient Kv algorithm. The flow coefficient Kv is a standard term in the field of valve technology, defined as: when the pressure difference across the valve is 100 kPa and the medium density is 1000 kg / m³. Under the condition that the valve is fully open, the volumetric flow rate of the medium flowing through the valve per hour (unit: In this embodiment, the symbols are defined as follows: P1 is the pressure before the valve, P2 is the pressure after the valve, and ΔP is the pressure difference (ΔP = P1 - P2). Let ρ be the target flow rate and ρ be the medium density.

[0058] The valve Kv data table is pre-stored in the non-volatile storage unit of the main control processing module and obtained through calibration on the flow test bench before shipment. For example... Figure 3 As shown, the automatic valve adjustment process includes the following steps: Step 1: Obtain the real-time inlet pressure P1 and outlet pressure P2, and calculate the pressure difference ΔP = P1 - P2. The units of P1 and P2 are kPa or MPa (P1 and P2 are in the same unit).

[0059] Step 2: Obtain target traffic and medium density According to the formula Calculate the theoretical flow coefficient. The unit is , The unit is kg / ΔP is P1-P2 and takes the same unit as P1 and P2.

[0060] Step 3: Retrieve the locally stored valve Kv data table and find the valve opening corresponding to the record closest to the theoretical Kv value as the target opening. For example, if the theoretical Kv value is 12.5, and the data table shows Kv values ​​of 10, 12, 14, and 16 corresponding to openings of 30%, 40%, 50%, and 60%, then the closest Kv value is 12, and the target opening is 40%. In another implementation, if the system allows slight overflow, the opening corresponding to the smallest Kv value not less than the theoretical Kv value can also be selected. The specific matching method can be set by the user through the accompanying debugging and control software.

[0061] Step 4: Convert the target opening degree into a 4-20mA or 0-10V analog control signal and output it to the actuator via the DAC channel.

[0062] Step 5: After the actuator completes its operation, the differential pressure is re-acquired, the theoretical Kv value is recalculated, and the opening degree is matched using a table. If the deviation between the newly matched opening degree and the current opening degree exceeds a preset threshold (typically ±2% of the target opening degree), adjustment continues; if the deviation is less than the preset threshold, the iteration stops. The number of iterations does not exceed 5, and the total adjustment time does not exceed 10 seconds. If the timeout occurs, the process is forcibly terminated, and the current opening degree is retained. The mathematical expression of the iterative adjustment process is as follows: set up Let be the valve opening at the k-th iteration, and let be the target flow rate. The density of the medium is Real-time pressure difference is The theoretical flow coefficient target value for: ; Current opening The flow coefficient obtained by looking up the valve Kv data table is: Then the iterative recurrence relation is: ; in, The equivalent correction gain is determined by the lookup table step size and the local slope of the Kv-aperture curve. The convergence condition for this iterative process is: ; in This represents the local slope of the Kv-opening curve at the current operating point (an inherent nonlinear characteristic of the valve). This convergence condition reveals that whether the iteration converges within 5 iterations or 10 seconds depends on the equivalent gain. The slope of the valve Kv curve near the current opening degree Whether the product satisfies the contraction mapping condition is an objective technical problem that makes the Kv curve of the valve steep and prone to oscillation overshoot in the small opening / large opening range. It also shows that the iteration step size / threshold needs to be tuned in coordination with the inherent nonlinear characteristics of the valve, rather than being set arbitrarily.

[0063] Step Six: Percentage Closed-Loop Fine-Tuning Mode. The user directly inputs the target opening percentage, and the main control processing module outputs a drive signal according to that percentage. Each iteration step size is a preset step size (preferably 1% to 5%), and it terminates when the deviation is less than a preset threshold. The number of iterations also does not exceed a preset number (preferably 5 times), and the total adjustment time does not exceed a preset time (preferably 10 seconds). If the timeout occurs, it will be forcibly terminated and the current opening will be retained.

[0064] It also includes an automatic Q-value adjustment mode, which directly retrieves the locally stored opening-flow table and matches the valve opening corresponding to the minimum flow value that is not less than the target flow.

[0065] Example 6: Non-volatile memory and hardware protection circuit. The main control processing module integrates a non-volatile memory unit, using an EEPROM or Flash memory chip (e.g., AT24C256), through... It connects to the main microcontroller via C or SPI bus to store user configuration parameters, valve Kv data tables, and opening-flow ratio tables. The data is not lost after power failure.

[0066] The controller hardware also includes hardware protection circuitry. Each analog channel is front-end equipped with a first- or second-order RC low-pass filter with a cutoff frequency of 100Hz to 500Hz. The controller housing is a sealed design with an IP65 or higher protection rating. Lightning protection devices, including gas discharge tubes, transient voltage suppressor diodes (TVS), varistors, or other equivalent surge suppression devices, are installed at the power input and communication interface terminals. Positive temperature coefficient thermistors (PTC) or resettable fuses are used in the analog output and power output channels. Zener diodes or TVS diodes are used at each power input and signal input interface. Reverse polarity protection circuits, such as series diodes or PMOS transistors, are installed at the power input and signal input terminals.

[0067] Example 7: Hierarchical Access Control. The accompanying debugging and control software runs on a mobile terminal, and its access control unit has a two-level password protection mechanism: an administrator password and a manufacturer unlock password. The administrator password is set by the user when using the software for the first time. The parameter configuration unit is divided into basic configuration and advanced configuration. Basic configuration (collection cycle, data upload interval, valve model selection, equipment name, etc.) does not require a password; advanced configuration (valve diameter, target flow rate Q, target pressure P, medium density ρ, actuator stroke, background upload server address, etc.) requires administrator password verification. The manufacturer unlock password is written to a non-volatile storage unit by the manufacturer during the production process for resetting if the user forgets the administrator password. The start-up and modification of the control parameters of the valve intelligent control unit also require verification with the administrator password.

[0068] Example 8: DAC Multi-point Matrix Interpolation Full-Temperature Range Calibration. This example uses a multi-point matrix interpolation calibration method to perform fine-grained calibration of the DAC across the entire temperature range of -40℃ to 85℃. Calibration is performed during the pre-shipment testing phase, using a high-precision ammeter or voltmeter with an accuracy better than 0.01% as the measurement standard. The steps are as follows: Step 1: Multi-point calibration data acquisition. Under room temperature conditions, the main control processing module sequentially writes digital input codes for multiple calibration points to the DAC. In a preferred embodiment, the calibration points are 0%, 25%, 50%, 75%, and 100% of the output range. For a 12-bit DAC, 0% corresponds to 0, 25% to 1024, 50% to 2048, 75% to 3072, and 100% to 4095. After writing each code value, the actual output value of the DAC is read, and each calibration point is measured three times and the average value is taken.

[0069] In other implementations, four-point calibration (0%, 33%, 67%, 100%) or six-point calibration (0%, 20%, 40%, 60%, 80%, 100%) can be used. For a 12-bit DAC, 20% corresponds to approximately 819, 40% to approximately 1638, 60% to approximately 2458, and 80% to approximately 3277.

[0070] Step 2: Establish the error compensation matrix. Calculate the output error (actual output value minus ideal output value) at each calibration point, and establish a piecewise interpolation function between the digital input code and the output error. Piecewise cubic spline interpolation is preferred; piecewise linear interpolation or piecewise quadratic interpolation can also be used. The piecewise interpolation function divides the entire digital input code range into multiple intervals, forming an error compensation matrix covering the entire range, which is stored in non-volatile memory.

[0071] Step 3: Full-temperature-range calibration. Place the controller in a high and low temperature test chamber, and repeat steps 1 and 2 at certain temperature intervals within the range of -40℃ to 85℃. Obtain the error compensation matrix at each temperature point and construct a two-dimensional temperature-error interpolation table.

[0072] Step 4: Real-time table lookup compensation. During runtime, the main control processing module reads the current operating temperature measured by the onboard temperature sensor and retrieves the error compensation value from the two-dimensional interpolation table using the temperature and the digital input code to be output as indexes. If the current temperature falls between two calibration temperature points, linear interpolation or spline interpolation is performed in the temperature dimension. The compensation value is then superimposed on the original digital input code and written to the DAC. Through the above calibration, the output linearity of the DAC can be significantly improved across the entire temperature range. The mathematical expression of the above calibration and compensation process is as follows: ; in, The digital code actually written to the DAC after compensation. The input code is the uncompensated raw DAC digital input code, where i is the code value calibration point and j is the temperature calibration point. Let be the error compensation matrix elements at the i-th code value calibration point and the j-th temperature calibration point. express The interpolation weights relative to adjacent calibration code value nodes i (using piecewise linear interpolation or cubic spline interpolation basis functions). This represents the interpolation weight of the current operating temperature T relative to the adjacent calibration temperature node j. Example 9: Online Diagnosis of Current Spectrum Analysis and Vibration Fingerprint Database. The controller hardware integrates a current spectrum analysis module, coupled to the output circuit of the analog output drive module, with a precision sampling resistor (0.1) connected in series in the actuator drive current circuit. -1 The voltage drop across the resistor is acquired via a differential amplifier (accuracy ±1%), filtered by an anti-aliasing filter (cutoff frequency 25kHz), and then fed into the ADC for sampling at a sampling rate of not less than 50kHz. Analysis of the spectral characteristics of the drive current of various types of electric actuators reveals that the current below 2kHz mainly consists of the fundamental frequency and low-order harmonics, while the current above 20kHz mainly consists of circuit white noise. The 2kHz~20kHz frequency band contains the main characteristic frequency components related to the mechanical state of the actuator (such as bearing rotation frequency, gear meshing frequency, etc.), therefore, 2kHz~20kHz is preferred as the analysis frequency band. In other embodiments, the preset frequency band can be adjusted within the range of 1kHz~30kHz depending on the actuator type and operating conditions.

[0073] Fingerprint database construction phase: When the valve actuator is in normal working condition, the main control processing module controls the actuator to run sequentially to multiple opening points (such as 0%, 10%, 20%, ..., 100%). After each opening point is running stably, the drive current signal of the preset frequency band is collected (not less than 1 second), and the spectrum feature vector is extracted by FFT transformation: (1) fundamental frequency amplitude; (2) second harmonic amplitude; (3) third harmonic amplitude; (4) spectrum energy distribution characteristics. The feature vector is associated with the current opening value and differential pressure value and stored to construct a typical working condition current spectrum fingerprint database, which is stored in a non-volatile storage unit.

[0074] Online diagnostic phase: During runtime, the current drive current spectrum is collected at set intervals (e.g., every 10 minutes), and feature vectors are extracted. The corresponding operating condition template is searched in the fingerprint database using the current opening value and differential pressure value as indexes, and the deviation between the real-time feature vector and the template is calculated. The deviation is calculated using normalized Euclidean distance. Let the i-th spectral feature component after real-time acquisition and normalization be... It includes the fundamental frequency amplitude, second harmonic amplitude, third harmonic amplitude, and spectral energy distribution characteristics. The corresponding feature components of the template under the same operating condition that matches the current opening value and pressure difference value in the fingerprint database are: The normalization scale (standard deviation) of the i-th feature component is The comprehensive anomaly score between the real-time spectrum and the template is: ; when If the threshold is exceeded, it is considered abnormal and a fault warning signal is generated.

[0075] In this embodiment, the fundamental frequency amplitude, second harmonic amplitude, third harmonic amplitude, and spectral energy distribution are not arbitrary data features, but rather physical quantities that correspond to the actual mechanical state of the actuator (such as bearing rotation frequency, gear meshing frequency, etc.). The comparison template is matched using a dual-condition index of opening value and differential pressure value to avoid misjudgment across operating conditions.

[0076] Example 10: Co-design of flexible thin-film shielded cavity and laser-etched heat dissipation window. The analog signal processing circuit of the signal acquisition module is arranged on the PCB board, and a flexible thin-film shielded cavity structure is used for electromagnetic shielding and thermal management.

[0077] The flexible film shielding cavity is formed by enclosing a flexible insulating substrate and a conductive shielding layer. The flexible insulating substrate is made of polyimide (PI) or polyethylene terephthalate (PET) film with a thickness of 25μm to 125μm. The conductive shielding layer covers at least one side of the substrate (single-sided or double-sided copper cladding, copper foil thickness 12μm to 35μm), and is bonded by hot pressing or adhesive bonding. The flexible film shielding material is cut, folded, and enclosed to form a box-shaped cavity with a bottom, four side walls, and a top opening. The analog signal processing circuit PCB board is placed inside the cavity. The conductive layer of the shielding cavity is grounded to the PCB digital ground through a single-point connection, with a grounding impedance of less than 100mΩ.

[0078] Laser-etched heat dissipation windows are formed on the conductive shielding layer. An ultraviolet laser beam scans the conductive shielding layer according to a preset pattern trajectory, precisely vaporizing and removing the copper foil to form multiple openings penetrating the conductive shielding layer. The opening width is a preset width (preferably 0.2mm to 0.5mm), the spacing is a preset spacing (preferably 1.0mm to 2.5mm), and the heat dissipation windows are located directly above the heat-generating area of ​​the circuit.

[0079] The 60dB shielding effectiveness requirement is determined based on the following: the typical electromagnetic interference intensity in industrial environments within the 2kHz~20kHz frequency band is approximately 50dBμV / m; the signal-to-noise ratio requirement for analog signal processing circuits is that the signal amplitude attenuation must be less than one-thousandth to ensure acquisition accuracy; therefore, the shielding effectiveness is determined to be no less than 60dB. Through optimized design of the opening width and spacing, the flexible thin-film shielding cavity simultaneously meets the heat dissipation requirements and the shielding effectiveness of no less than 60dB in the 2kHz~20kHz frequency band.

[0080] The shielding effectiveness of the conductive shielding layer's heat dissipation window region is physically related to the opening geometry parameters as follows: Approximating each laser-etched opening on the heat dissipation window as a small rectangular waveguide operating below the cutoff frequency, when the opening width W is much smaller than the wavelength corresponding to the 2kHz–20kHz interference signal, a single opening exhibits exponential attenuation of the transmitted field: ; in, The formula represents the overall shielding effectiveness (in dB) of the conductive shielding layer's heat dissipation window area against electromagnetic interference in the target frequency band; t represents the effective depth of a single laser-etched opening (approximately the thickness of the shielding layer / insulating substrate stack); W represents the preset width of a single opening; and N represents the number of openings arranged at a preset spacing per unit area (array leakage superposition factor). The first term of this formula represents the classical waveguide cutoff attenuation mechanism, and the second term is a correction term for leakage coupling in a multi-opening array. This model illustrates that the opening width and opening spacing are not isolated parameters, but rather a pair of coupled design variables that simultaneously determine two mutually constraining technical indicators: shielding effectiveness and available heat dissipation area. Narrowing / sparser openings are beneficial for shielding but weaken the heat dissipation path, while widening / dense openings have the opposite effect.

[0081] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A smart data acquisition controller for valves, characterized in that, This includes the controller hardware and the accompanying debugging and control software; The controller hardware includes a main control processing module, a signal acquisition module, an analog output drive module, a multi-channel power supply module, a multi-mode communication module, and a human-machine interaction module. The signal acquisition module is equipped with an analog input channel and a temperature acquisition channel, which are used to acquire the pressure before the valve, the pressure after the valve, the actuator feedback signal, and the supply and return water temperature. The analog output drive module is equipped with a conversion output channel for outputting analog signals to drive the valve actuator; The multi-power supply module integrates three power supplies: battery input, DC input, and AC input. The DC input and the AC input take priority over the battery input. When only the battery input is powered, the whole machine switches to a low-power mode. The multimode communication module includes a short-range wireless communication module, a slot-type replaceable cellular communication module, and a wired bus interface. The accompanying debugging and control software runs on a mobile terminal and includes a network distribution unit, a parameter configuration unit, and a valve intelligent control unit. The network distribution unit is used for Bluetooth connection to complete Wi-Fi network distribution and server address configuration. The parameter configuration unit is used to read and modify the controller's operating parameters, with advanced configuration functions requiring password verification. The valve intelligent control unit calculates the pressure difference based on the collected inlet and outlet pressures, calculates the flow coefficient based on the target flow rate and medium density, retrieves the valve data table to match the target opening degree closest to the flow coefficient, and outputs a control signal to the actuator. After adjustment, the differential pressure is re-acquired, the theoretical flow coefficient is recalculated, and the opening degree is re-matched by looking up the table. If the deviation between the matched opening degree and the current opening degree is greater than the preset threshold, the adjustment continues. If the deviation is less than the preset threshold, the iteration stops.

2. The intelligent data acquisition controller for valves according to claim 1, characterized in that, The analog input channels are three 4-20mA channels, which respectively acquire the valve inlet pressure, valve outlet pressure, and actuator position feedback signal, with an acquisition accuracy of no less than 16 effective bits for the ADC; the temperature acquisition channels are two PT1000 RTD channels, which respectively acquire the supply water temperature and return water temperature, with an acquisition accuracy of no less than 14 effective bits for the ADC; the conversion output channels are DAC digital-to-analog conversion channels, outputting a 4-20mA current signal or a 0-10V voltage signal, with a full-range linearity of analog output better than 0.15%.

3. The intelligent data acquisition controller for valves according to claim 1, characterized in that, The multi-channel power supply module has a lithium battery as the battery input, a wide-voltage power supply as the DC input, and a mains power supply as the AC input, and is also equipped with a wind power or solar power supply interface; the main control processing module is configured to: when it detects that the battery input is providing power, if the cellular communication module is an NB-IoT module, then enable it to communicate. If it is a 4G module, then cellular communication will be disabled or a low battery warning will be issued.

4. The intelligent data acquisition controller for valves according to claim 1, characterized in that, The human-machine interaction module includes a three-color indicator light with integrated button function, an independent power indicator light, an independent network configuration button, and an external display interface; when the network configuration button is pressed, Bluetooth network configuration mode is enabled, and when pressed again, Bluetooth is disabled; the three-color indicator light indicates normal operation in green, low power in yellow, and device malfunction in red.

5. The intelligent data acquisition controller for valves according to claim 1, characterized in that, The valve intelligent control unit automatically adjusts based on the flow coefficient Kv algorithm, and its adjustment process includes: Step 1: Obtain the real-time inlet pressure P1 and outlet pressure P2, and calculate the pressure difference. =P1-P2; Step 2: Based on the target traffic and medium density According to the formula Calculate the theoretical flow coefficient; Step 3: Retrieve the locally stored valve Kv data table and match the valve opening corresponding to the Kv value that is closest to the theoretical flow coefficient; Step 4: Convert the valve opening degree into a 4-20mA or 0-10V analog control signal, and output it to the actuator through the conversion output channel; Step 5: After adjustment, re-collect the differential pressure, recalculate the theoretical Kv value, and re-match the opening degree by looking up the table; if the deviation between the matched opening degree and the current opening degree is greater than the preset threshold, continue adjustment; if the deviation is less than the preset threshold, stop iteration. Step 6: The valve intelligent control unit also includes a percentage closed-loop fine-tuning mode. In this mode, the drive signal is output according to the opening percentage. The step size of each iteration is a preset step size. The iteration is terminated when the deviation between the actual opening and the target opening is less than the preset threshold.

6. The intelligent data acquisition controller for valves according to claim 1, characterized in that, The main control processing module integrates a non-volatile storage unit to save user configuration parameters, valve Kv data table, and opening degree-flow ratio table; the controller hardware body is also equipped with a hardware protection circuit, which adopts diaphragm isolation and frequency cutoff anti-interference design, and integrates waterproof, lightning protection, current limiting, voltage limiting and reverse connection protection, and the whole machine has a wide operating temperature range.

7. The intelligent data acquisition controller for valves according to claim 1, characterized in that, The supporting debugging and control software also includes a permission management unit, which sets an administrator password and a manufacturer unlock password; the parameter configuration unit is divided into basic configuration and advanced configuration, and the advanced configuration function requires verification with the administrator password; the start-up and modification of the control parameters of the valve intelligent control unit also require verification with the administrator password; the manufacturer unlock password is used to reset the administrator password if it is forgotten.

8. The intelligent data acquisition controller for valves according to claim 1, characterized in that, The DAC digital-to-analog conversion channel uses a multi-point matrix interpolation calibration method for linearity correction. The calibration method includes: acquiring actual output values ​​at multiple calibration points within the DAC output range, establishing a piecewise interpolation function between the output error and the digital input code, and forming an error compensation matrix; repeatedly calibrating at multiple temperature points within the operating temperature range to obtain the error compensation matrix at each temperature point, and constructing a temperature-error two-dimensional interpolation table; and retrieving the two-dimensional interpolation table for error compensation during real-time control based on the current operating temperature measured by the onboard temperature sensor.

9. A smart data acquisition controller for valves according to claim 1, characterized in that, The controller hardware also integrates a current spectrum analysis module, coupled with the output circuit of the analog output drive module, for acquiring drive current signals of the actuator in preset frequency bands at different opening degrees, extracting the spectral feature vectors corresponding to each opening point, including fundamental frequency amplitude, second harmonic amplitude, third harmonic amplitude, and spectral energy distribution characteristics, and storing them in association with opening value and differential pressure value to construct a typical operating condition current spectrum fingerprint database; the main control processing module acquires the current spectrum in real time during operation and matches it with the current spectrum fingerprint database, and generates a fault warning signal when the deviation between the real-time spectrum and the spectral features of the corresponding operating condition in the fingerprint database exceeds a preset threshold.

10. A smart data acquisition controller for valves according to claim 1, characterized in that, The PCB board of the signal acquisition module is provided with a flexible thin film shielding cavity. The flexible thin film shielding cavity is formed by a flexible insulating substrate and a conductive shielding layer covering at least one side thereof. The analog signal processing circuit of the signal acquisition module is arranged inside the flexible thin film shielding cavity. Laser-etched heat dissipation windows are provided on the conductive shielding layer. The heat dissipation windows consist of multiple openings that penetrate the conductive shielding layer. The opening width and spacing are preset. The heat dissipation windows are optimized so that the shielding cavity can simultaneously meet the following requirements within a wide temperature range: the maximum operating temperature of the analog signal processing circuit does not exceed 85℃; and the shielding effectiveness against electromagnetic interference in the 2kHz~20kHz frequency band is not less than 60dB.

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