A high-precision positioning system for water treatment multi-way control valves based on magnetic induction

Abstract

The present invention relates to the field of control valve positioning, and discloses a high-precision positioning system for a water treatment multi-way control valve based on magnetic induction. Through the rigid linkage between the magnet and the valve core drive unit, accurate mapping of the magnet rotation / linear motion and the valve core position is achieved. An array of induction devices is used to non-contactly detect the three-dimensional magnetic field gradient changes along the magnet movement trajectory, and the sensor array is arranged in a circumferential ring or axial straight line. Through a pre-calibrated magnetic field strength-spatial position multidimensional database and a two-level matching strategy. For long-stroke applications, sensor relay detection technology is adopted. The present invention has the advantages of high precision, high reliability and low cost, and is suitable for water treatment, industrial automation and other fields.

Description

Technical Field

[0001] The present invention relates to the field of control valve positioning, and in particular to a high-precision positioning system for a water treatment multi-way control valve based on magnetic induction. Background Art

[0002] In water treatment equipment, the multi-way control valve is an indispensable component and a key component in the water treatment equipment. Without it, the water treatment equipment cannot perform water treatment. The core problem of the multi-way control valve is that it needs to be accurately positioned at the position of each workstation. To accurately position, various sensors are needed to sense the position of the valve. The problems of the multi-way control valve on the market now are: inaccurate positioning; the sensor is prone to failure, resulting in abnormal use, and even leakage leading to accidents; the complexity of the sensor leads to a complex structure, many parts, complex assembly, and high overall cost.

[0003] The positioning sensing technologies used by existing multi-way control valves are optical sensing technology and magnetic induction technology. They use grating encoding to obtain the angle of rotation of the wheel by using the pulses that block light when the wheel rotates, and calculate the distance or angle traveled by the valve, thereby obtaining the position of the valve. This method is generally an incremental encoding method, without absolute position, and often requires other sensors to obtain the starting position or ending position to determine the zero position of the valve, such as Hall, touch switch, etc., in order to work properly. Due to structural and cost limitations, the encoder accuracy is not high, and the valve control accuracy is not high either. The absolute position sensing method is to use the grating shape and size on the wheel to identify the different light blocking times to know the position of the valve. However, the disadvantage of this method is that it is easily affected by the resistance of the valve, manufacturing inconsistencies, etc., resulting in inaccurate or erroneous sensing.

[0004] Magnetic induction technology uses one or more magnets. When the magnets are far away from the sensing device, there will be a phenomenon of signal separation. Even if there are multiple magnets, similar situations will exist between two adjacent magnets, providing pulses when the wheel rotates, thereby calculating the position of the valve.

[0005] The two sensing methods based on the above principles will have the same problem, that is, the problem of sensing accuracy. For example, in the magnetic induction method, the sensing device has a certain sensing distance and angle. When the sensor device obtains the desired positioning position, the valve is not in the most accurate connection position.

[0006] Therefore, we proposed a high-precision positioning system for water treatment multi-way control valves based on magnetic induction to solve the above problems. Summary of the Invention

[0007] The invention provides a high-precision positioning system for a water treatment multi-way control valve based on magnetic induction.

[0008] The first aspect of the present invention provides a high-precision positioning system for a water treatment multi-way control valve based on magnetic induction, and the high-precision positioning system for a water treatment multi-way control valve based on magnetic induction includes: a construction module, which is used to form a rigid linkage between a magnet and a valve core drive unit through a mechanical connection structure, so that the rotation axis of the magnet is coaxially fixed with the rotation axis of the valve core, or the linear motion trajectory of the magnet is aligned parallel to the motion trajectory of the valve core piston; a detection module, which is used to arrange an array of sensing devices along the motion trajectory of the magnet, and non-contact and continuously detect the three-dimensional magnetic field intensity gradient changes generated when the magnet moves based on the sensing device array to obtain a multi-channel analog signal of the magnetic field intensity; a processing module, which is used to digitize the multi-channel analog signal of the magnetic field intensity output by the sensing device array to obtain a multi-channel digital signal; an output module, which is used to calculate the magnet rotation angle or linear displacement in real time based on the multi-channel digital signal, combined with a pre-experimentally calibrated magnetic field intensity-spatial position mapping relationship database, and compare the calculation result with a preset work position angle / displacement threshold to solve the absolute position coordinates of the valve core in real time to achieve valve positioning control.

[0009] Optionally, in a first implementation method of the first aspect of the present invention, a spline coupling is used to rigidly connect the rotating axis of the magnet and the rotating axis of the valve core, and a laser alignment instrument installed on the end face of the coupling is used to detect the coaxiality deviation of the two axes to form a 1:1 mapping relationship between the magnet rotation angle and the valve core position angle; a dovetail groove guide rail is provided on the side wall of the valve core piston rod, and the magnet is embedded in the guide rail through a slider assembly and a pre-tightening force is applied, and a laser interferometer is used to measure the parallelism of the magnet's linear motion trajectory and the piston motion trajectory to form a linear proportional relationship between the magnet displacement and the valve core position displacement; the valve core is driven to perform full-stroke movement, and the magnetic field strength data is collected through the sensing device array. If a discontinuous jump point is detected in the magnetic field strength change curve, it is determined that there is a mechanical gap in the linkage mechanism, and it needs to be re-executed until the magnetic field strength curve is continuous and smooth.

[0010] Optionally, in a second implementation of the first aspect of the present invention, the method includes: processing an annular sensor mounting groove or a linear sensor guide rail on the inner wall of the valve body shell, embedding the sensing device units into the mounting groove / guide rail in a circumferential annular array or an axial linear array, and the center spacing between adjacent sensor units is 1.2-1.5 times the effective detection radius of the sensor, forming a 10%-25% overlap in the detection area; synchronously reading the analog signals output by all sensor units through a multi-channel synchronous sampling circuit, performing differential amplification processing on the signals of each channel, eliminating common-mode interference and then inputting them into a 16-bit analog-to-digital converter; extracting the instantaneous value of the magnetic field strength of each sensor channel from the multi-channel digital signal after analog-to-digital conversion. , the magnetic field intensity gradient between adjacent sensor channels ,in, is the distance between sensors i and j, and the rate of change of magnetic field intensity During the system power-on initialization phase, the control valve core performs three full-stroke reciprocating motions and records the extreme magnetic field strength of each sensor channel. 、 , calculate the dynamic baseline threshold :

[0011] ;When real-time detection < The sensor sensitivity self-adjustment program is triggered.

[0012] Optionally, in a third implementation of the first aspect of the present invention, the analog signals of each sensor output by the multi-channel synchronous sampling circuit are input into a differential amplifier, common-mode interference is eliminated by setting a differential amplifier circuit with a common-mode rejection ratio ≥ 80dB, and low-frequency mechanical vibration noise and high-frequency electromagnetic interference are filtered out; a 16-bit analog-to-digital converter is used to digitize the pre-processed analog signal in an independent sampling manner for each channel, and the sampling rate is dynamically adjusted according to the valve core movement speed: when the valve core movement speed is ≤5mm / s, a 10kHz sampling rate is used, and when the speed is >5mm / s, the sampling rate is proportionally increased to 50kHz; based on a dynamic baseline threshold , perform normalization processing on the digital signal of each channel and calculate the normalized magnetic field intensity value :

[0013] ;

[0014] Signals exceeding ±120% of the measurement range are marked as abnormal data. The normalized multi-channel digital signals are aligned according to timestamps to generate structured data frames.

[0015] Optionally, in the fourth implementation of the first aspect of the present invention, the method includes: during the system debugging phase, driving the valve core to perform full stroke movement at a uniform speed of 0.1 mm / s, and synchronously recording the theoretical spatial coordinates of each work station. , the mean magnetic field strength of all sensor channels at the corresponding position and gradient extremum , ambient temperature value and electromagnetic interference baseline value , store the above data into a multidimensional calibration table, where each entry contains ;

[0016] Receive structured data frame, according to the current ambient temperature value Filter from calibration table , calculate the real-time magnetic field strength mean value among the filtered entries With each entry The Euclidean distance of the first five candidate positions with the smallest distance is selected, and the gradient extreme value corresponding to the candidate position is calculated. and real-time gradient extremum Sort the matching degree and select the position with the highest matching degree as the initial solution result;

[0017] Based on the initial solution results, if the current electromagnetic interference value Exceeds the corresponding entry in the calibration table ±15%, then enable the marked abnormal data filtering results, remove the disturbed channel data and recalculate. If the ambient temperature change rate is , then add the temperature drift compensation to the solution result , where the compensation coefficient α is measured by pre-calibration experiment;

[0018] The calculated coordinates after compensation Compare with the preset position threshold: For linear positioning, if , it is determined that the target position has been reached. For rotation positioning, if , then generate the valve in-position control signal.

[0019] Optionally, in the fifth implementation of the first aspect of the present invention, during rotational positioning, the initial position magnetic field intensity distribution curve of the magnet is identified by a feature matching algorithm and set as the reference zero point; during operation, when it is detected that the correlation coefficient between the current magnetic field intensity distribution curve and the reference zero point drops to the range of 0.92-0.95, a nonlinear compensation program based on a back propagation neural network is automatically triggered to correct the positioning error caused by demagnetization and mechanical deformation of the permanent magnet.

[0020] Optionally, in a sixth implementation of the first aspect of the present invention, for valve core movement with a linear displacement exceeding 200 mm, at least three of the sensing device units are arranged equidistantly along the direction of movement, and the spacing between adjacent sensor units is 70%-80% of the effective detection range of the sensor. The full-stroke positioning accuracy is maintained within ±0.1 mm through sensor relay data fusion.

[0021] Beneficial effects of the present invention:

[0022] Magnetic induction technology does not use on-off technology, but uses linear induction technology to calculate the rotation angle of the magnet, thereby accurately positioning the multi-way control valve or calculating the displacement of the magnet relative to the induction device, thereby accurately positioning the multi-way control valve;

[0023] It gets rid of the influence of manufacturing process on accuracy, because both the current and previous magnetic induction (pulse type) will be affected by resistance, motor speed and other manufacturing process factors, and will not cause failure or leakage due to sensor failure, and has a long service life. Optical sensors are prone to failure after long-term work;

[0024] The structure is simple, without complicated mechanical structure, and the cost is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a flow chart in an embodiment of the present invention;

[0026] Figure 2 Schematic diagram of the configuration of a high-precision positioning system for a water treatment multi-way control valve based on magnetic induction according to an embodiment of the present invention;

[0027] Figure 3 A schematic diagram of an embodiment of a high-precision positioning system for a water treatment multi-way control valve based on magnetic induction in an embodiment of the present invention;

[0028] Figure 4 It is a schematic diagram of some principles in an embodiment of the present invention. DETAILED DESCRIPTION

[0029] An embodiment of the present invention provides a high-precision positioning system for a water treatment multi-way control valve based on magnetic induction. The terms "first", "second", "third", "fourth", etc. (if any) in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate so that the embodiments described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "including" or "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0030] For ease of understanding, the specific process of the embodiment of the present invention is described below. Figure 1-3 An embodiment of a high-precision positioning system for a water treatment multi-way control valve based on magnetic induction in an embodiment of the present invention includes:

[0031] 101. A construction module for forming a rigid linkage between the magnet 1 and the valve core drive unit through a mechanical connection structure, so that the rotation axis of the magnet 1 is coaxially fixed with the rotation axis of the valve core, or the linear motion trajectory of the magnet 1 is aligned parallel to the motion trajectory of the valve core piston;

[0032] It is understood that the execution subject of the present invention can be a high-precision positioning device for a water treatment multi-way control valve based on magnetic induction, or a terminal or a server, which is not limited here. The embodiment of the present invention is described by taking the server as the execution subject as an example.

[0033] Specifically, a1: Use a spline coupling to rigidly connect the rotating axis of magnet 1 to the rotating axis of the valve core. Use a laser alignment instrument installed on the end face of the coupling to detect the coaxial deviation of the two axes. Adjust the installation angle until the coaxial error is ≤ 0.02mm, forming a 1:1 mapping relationship between the magnet rotation angle and the valve core position angle.

[0034] a2: Create a dovetail groove guide rail on the side wall of the valve core piston rod. Insert the magnet 1 into the guide rail through the slider assembly and apply a preload. Use a laser interferometer to measure the parallelism between the magnet's linear motion trajectory and the piston's motion trajectory. Adjust the parallelism to a parallelism error of ≤0.03mm / m, forming a linear proportional relationship between the magnet displacement and the valve core position displacement.

[0035] a3: Drive the valve core to perform full stroke movement and collect magnetic field strength data through the sensing device array (linear Hall sensor). If a discontinuous jump point is detected in the magnetic field strength curve, it is determined that there is mechanical clearance in the linkage mechanism. Step a1 or a2 must be repeated until the magnetic field strength curve is continuous and smooth.

[0036] The coaxiality error value generated in step a1 is used as the input parameter of the weighted least squares algorithm to adjust the multi-sensor data fusion weight; the parallelism error value measured in step a2 is used as the benchmark parameter for calculating the sensor relay spacing.

[0037] 102. A detection module, configured to arrange an array of sensing devices at intervals along the circumferential or axial direction of the motion trajectory of the magnet 1, wherein the detection areas of the sensor units in the sensing device array have a spatial overlap rate of 10%-25%, and to obtain a multi-channel analog signal of the magnetic field intensity by continuously and non-contactly detecting the three-dimensional magnetic field intensity gradient change generated by the motion of the magnet 1 based on the sensing device array;

[0038] Specifically, b1: Process an annular sensor mounting groove or a linear sensor guide rail on the inner side wall of the valve body shell, and embed the sensing device units into the mounting groove / guide rail in a circumferential annular array or an axial linear array. The center spacing between adjacent sensor units is 1.2-1.5 times the effective detection radius of the sensor, resulting in a 10%-25% overlap in the detection area.

[0039] b2: The analog signals output by all sensor units are synchronously read at a sampling rate of 10kHz-50kHz through a multi-channel synchronous sampling circuit, and each channel signal is differentially amplified to eliminate common-mode interference before being input into a 16-bit analog-to-digital converter;

[0040] b3: Extract the following features from the multi-channel digital signal after analog-to-digital conversion:

[0041] Instantaneous value of magnetic field strength of each sensor channel ;

[0042] Magnetic field intensity gradient between adjacent sensor channels ;

[0043] in, is the distance between sensors i and j;

[0044] Magnetic field intensity change rate ;

[0045] b4: During the system power-on initialization phase, the control valve core performs three full-stroke reciprocating motions and records the extreme values ​​of the magnetic field intensity of each sensor channel. 、 , calculate the dynamic baseline threshold :

[0046] ;

[0047] When real-time detection < When the sensor sensitivity self-adjustment program is triggered;

[0048] Among them, the output of step b3 is As the input parameter of the weighted least squares algorithm, it is used to calculate the magnet movement direction vector; the vector generated in step b4 Serves as an abnormal data filtering threshold for dynamic zero calibration.

[0049] 103. A processing module, configured to digitally process the multi-channel analog signal of the magnetic field intensity output by the sensing device array to obtain a multi-channel digital signal;

[0050] Specifically, c1: Input the analog signals of each sensor output by the multi-channel synchronous sampling circuit into the differential amplifier, eliminate common-mode interference by setting a differential amplifier circuit with a common-mode rejection ratio ≥ 80dB, and use a bandpass filter with a cutoff frequency of 1kHz-10kHz to filter out low-frequency mechanical vibration noise and high-frequency electromagnetic interference;

[0051] c2: Use a 16-bit analog-to-digital converter to digitize the pre-processed analog signal with independent sampling per channel. The sampling rate is dynamically adjusted according to the valve core movement speed: when the valve core movement speed is ≤5mm / s, the sampling rate is 10kHz, and when the speed is >5mm / s, the sampling rate is proportionally increased to 50kHz.

[0052] c3: Dynamic baseline threshold generated based on step b4 , perform normalization processing on the digital signal of each channel and calculate the normalized magnetic field intensity value :

[0053] ;

[0054] And mark the signal exceeding ±120% of the range as abnormal data;

[0055] c4: Align the normalized multi-channel digital signals by timestamp to generate a structured data frame containing the following fields: sensor channel number, normalized magnetic field strength value, and signal validity flag based on abnormal data mark;

[0056] Among them, the sampling rate value dynamically adjusted in step c2 serves as the synchronization benchmark for data frame timestamp alignment; the abnormal data mark output in step c3 is directly input into the dynamic zero point calibration module to trigger the calibration procedure; and the structured data frame serves as the only input source for the weighted least squares algorithm.

[0057] 104. Output module, used to calculate the magnet rotation angle or linear displacement in real time based on the pre-experimentally calibrated magnetic field strength-spatial position mapping relationship database, compare the calculated result with the preset position angle / displacement threshold, and calculate the absolute position coordinates of the valve core in real time to achieve valve positioning control;

[0058] Specifically, c5: Pre-calibration database construction:

[0059] During the system debugging phase, the valve core is driven to perform full stroke motion at a uniform speed of 0.1 mm / s, and the following data is simultaneously recorded to generate a magnetic field intensity-spatial position mapping database:

[0060] Theoretical spatial coordinates of each workstation ;

[0061] The average magnetic field strength of all sensor channels at the corresponding position and gradient extremum ;

[0062] Ambient temperature value and electromagnetic interference baseline value ;

[0063] The above data is stored as a multidimensional calibration table, where each entry contains ;

[0064] It should be noted that the system is configured for a full 360° rotation of the valve core, with a theoretical station interval of 45°. During commissioning, a constant-speed drive was used, the ambient temperature was controlled at 25 ± 2°C, and electromagnetic interference was stabilized at a baseline level using shielding. The sensor array was arranged with an 80% detection range overlap.

[0065] The sensor accuracy is set to ±0.01 mT, and the influence of environmental factors has been corrected through multiple tests;

[0066] Four representative entries in the multi-dimensional calibration table are shown below (the actual table contains all eight stations) as shown in Table 1:

[0067] Table 1

[0068]

[0069] At an angle of 0°, the average magnetic field strength is low (1.55 mT) because the magnetic field is weak at the initial position of the magnet; the extreme gradient is small (0.03 mT / deg), indicating that the magnetic field changes smoothly.

[0070] At an angle of 135°, the magnetic field is enhanced (6.10 mT) and the extreme gradient increases (0.09 mT / deg), reflecting the peak magnetic field gradient caused by the movement of the magnet.

[0071] The ambient temperature is maintained at around 25°C, and the electromagnetic interference baseline value is stable (2.0-2.3 mV), indicating that the debugging environment is under control.

[0072] The calibration table is stored in the controller's non-volatile memory in a structured list format where each entry can be directly indexed.

[0073] During the debugging phase, the system automatically records the above data: first, the valve core is driven to each working position, and the sensor output is collected in real time (at the 90° working position, the average value of the four sensors is 4.85 mT, and the maximum gradient difference between adjacent channels is calculated as the gradient extreme value). and All data are integrated into a table format to facilitate subsequent real-time position calculation (step c6).

[0074] In real-time operation, the table is used to match current measurements: When the system detects a current magnetic field average of 5.0 mT, a gradient of 0.06 mT / deg, a temperature of 25.2°C, and an EM interference of 2.1 mV, it searches the calibration table to find the closest entry (such as the 90° point in this example) and outputs an estimated valve spool angle, achieving high-precision positioning.

[0075] c6: Real-time position calculation:

[0076] Receive the structured data frame output from step c4 and perform the following operations:

[0077] According to the current ambient temperature Filter from calibration table A collection of entries;

[0078] Calculate the real-time mean magnetic field strength of the filtered entries With each entry The Euclidean distance of , select the top 5 candidate positions with the smallest distance;

[0079] The gradient extreme value corresponding to the candidate position and real-time gradient extremum Sort the matching degree and select the position with the highest matching degree as the initial solution result;

[0080] c7: Dynamic error compensation:

[0081] Based on the initial solution results, the following compensation operations are performed:

[0082] If the current electromagnetic interference value Exceeds the corresponding entry in the calibration table If the value is ±15%, the abnormal data filtering result marked in step c3 is enabled, and the disturbed channel data is removed and the solution is recalculated;

[0083] If the ambient temperature change rate , then add the temperature drift compensation to the solution result

[0084] , where the compensation coefficient α is measured by pre-calibration experiment;

[0085] c8: Workstation threshold comparison:

[0086] The calculated coordinates after compensation Compare with the preset workstation threshold:

[0087] For linear positioning, if , it is determined that the target station has been reached;

[0088] For rotation positioning, if , then the valve in-position control signal is generated;

[0089] Among them, the calibration table generated in step c5 serves as the only data source for all real-time solution operations; the compensation coefficient α in step c7 is pre-stored in the non-volatile memory of the controller in the form of parameters; and the in-position control signal output in step c8 directly drives the valve actuator to lock the current position.

[0090] Reference Figure 4 When magnet 1 rotates with the wheel, the magnetic field around induction device 2 changes, and induction device 2 can output a corresponding signal. This signal can be calculated to obtain the rotation angle of the wheel. We can define any point A, B, or C on the wheel as the zero point. In this way, the angles of other positions relative to this zero point are fixed.

[0091] During rotational positioning, the magnetic field intensity distribution curve of the initial position of magnet 1 is identified through a feature matching algorithm and set as the reference zero point. During operation, when the correlation coefficient between the current magnetic field intensity distribution curve and the reference zero point is detected to drop to the range of 0.92-0.95, the nonlinear compensation program based on the back propagation neural network is automatically triggered to correct the positioning error caused by permanent magnet demagnetization and mechanical deformation.

[0092] For valve core movement with a linear displacement exceeding 200mm, at least three sensing devices 2 are arranged equidistantly along the direction of movement. The spacing between adjacent sensor units is 70%-80% of the effective detection range of the sensor. The full-stroke positioning accuracy is maintained within ±0.1mm through sensor relay data fusion.

[0093] The present invention also provides a high-precision positioning device for a water treatment multi-way control valve based on magnetic induction. The high-precision positioning device for a water treatment multi-way control valve based on magnetic induction includes a memory and a processor. The memory stores computer-readable instructions. When the computer-readable instructions are executed by the processor, the processor executes the steps of the high-precision positioning system for a water treatment multi-way control valve based on magnetic induction in the above-mentioned embodiments.

[0094] The present invention also provides a computer-readable storage medium, which can be a non-volatile computer-readable storage medium or a volatile computer-readable storage medium. The computer-readable storage medium stores instructions. When the instructions are run on a computer, the computer executes the steps of the high-precision positioning system for the water treatment multi-way control valve based on magnetic induction.

[0095] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0096] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the portion that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes various media that can store program code, such as a USB flash drive, a mobile hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0097] As described above, the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions described in the above embodiments can still be modified, or some of the technical features thereof can be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high-precision positioning system for a water treatment multi-way control valve based on magnetic induction, characterized in that: The high-precision positioning system for the water treatment multi-way control valve based on magnetic induction includes: A construction module is used to form a rigid linkage between the magnet and the valve core drive unit through a mechanical connection structure, so that the rotation axis of the magnet is fixed coaxially with the rotation axis of the valve core, or the linear motion trajectory of the magnet is aligned parallel to the motion trajectory of the valve core piston; a detection module, configured to arrange an array of sensing devices along the motion trajectory of the magnet, and to continuously and contactlessly detect the three-dimensional magnetic field intensity gradient changes generated by the movement of the magnet using the array of sensing devices, thereby obtaining a multi-channel analog signal of the magnetic field intensity; a processing module, configured to digitally process the multi-channel analog signal of the magnetic field intensity output by the sensing device array to obtain a multi-channel digital signal; The output module is used to calculate the magnet rotation angle or linear displacement in real time based on the multi-channel digital signal in combination with a pre-experimentally calibrated magnetic field strength-spatial position mapping relationship database, and compare the calculated result with the preset position angle / displacement threshold to solve the absolute position coordinates of the valve core in real time to achieve valve positioning control.

2. The high-precision positioning system for a water treatment multi-way control valve based on magnetic induction according to claim 1 is characterized in that: include: A spline coupling is used to rigidly connect the rotating axis of the magnet and the rotating axis of the valve core. A laser alignment instrument installed on the end face of the coupling is used to detect the coaxiality deviation of the two axes to form a 1:1 mapping relationship between the magnet rotation angle and the valve core position angle; A dovetail groove guide rail is provided on the side wall of the valve core piston rod, the magnet is embedded in the guide rail through a slider assembly and a pre-tightening force is applied, and a laser interferometer is used to measure the parallelism between the linear motion trajectory of the magnet and the motion trajectory of the piston, thereby forming a linear proportional relationship between the displacement of the magnet and the displacement of the valve core position; The valve core is driven to perform full-stroke movement, and magnetic field strength data is collected through the sensing device array. If a discontinuous jump point is detected in the magnetic field strength change curve, it is determined that there is a mechanical gap in the linkage mechanism and it needs to be re-executed until the magnetic field strength curve is continuous and smooth.

3. The high-precision positioning system for a water treatment multi-way control valve based on magnetic induction according to claim 2 is characterized in that: include: Process an annular sensor mounting groove or a linear sensor guide rail on the inner wall of the valve body shell, and embed the sensing device units into the mounting groove / guide rail in a circumferential annular array or an axial linear array. The center spacing between adjacent sensor units is 1.2-1.5 times the effective detection radius of the sensor, forming a 10%-25% overlap in the detection area; The analog signals output by all sensor units are synchronously read through a multi-channel synchronous sampling circuit, and each channel signal is differentially amplified and input into a 16-bit analog-to-digital converter after eliminating common-mode interference; Extract the instantaneous value of the magnetic field strength of each sensor channel from the multi-channel digital signal after analog-to-digital conversion , the magnetic field intensity gradient between adjacent sensor channels ,in, is the distance between sensors i and j, and the rate of change of magnetic field intensity ; During the system power-on initialization phase, the control valve core performs three full-stroke reciprocating motions and records the extreme values ​​of the magnetic field intensity of each sensor channel. 、 , calculate the dynamic baseline threshold : ; When real-time detection < The sensor sensitivity self-adjustment program is triggered.

4. The high-precision positioning system for a water treatment multi-way control valve based on magnetic induction according to claim 3 is characterized in that: include: The analog signals of each sensor output by the multi-channel synchronous sampling circuit are input to the differential amplifier. The differential amplifier circuit is set with a common mode rejection ratio of ≥80dB to eliminate common mode interference and filter out low-frequency mechanical vibration noise and high-frequency electromagnetic interference. The pre-processed analog signal is digitized using a 16-bit analog-to-digital converter with independent sampling per channel. The sampling rate is dynamically adjusted according to the valve core movement speed: when the valve core movement speed is ≤5mm / s, the sampling rate is 10kHz, and when the speed is >5mm / s, the sampling rate is proportionally increased to 50kHz. Based on dynamic baseline threshold , perform normalization processing on the digital signal of each channel and calculate the normalized magnetic field intensity value : ； And mark the signal exceeding ±120% of the range as abnormal data; The normalized multi-channel digital signals are aligned according to timestamps to generate structured data frames.

5. The high-precision positioning system for a water treatment multi-way control valve based on magnetic induction according to claim 4 is characterized in that: include: During the system debugging phase, the valve core is driven to perform full stroke movement at a uniform speed of 0.1 mm / s, and the theoretical spatial coordinates of each work station are recorded simultaneously. , the mean magnetic field strength of all sensor channels at the corresponding position and gradient extremum , ambient temperature value and electromagnetic interference baseline value , store the above data into a multidimensional calibration table, where each entry contains ; Receive structured data frame, according to the current ambient temperature value Filter from calibration table , calculate the real-time magnetic field strength mean value among the filtered entries With each entry The Euclidean distance of the first five candidate positions with the smallest distance is selected, and the gradient extreme value corresponding to the candidate position is calculated. and real-time gradient extremum Sort the matching degree and select the position with the highest matching degree as the initial solution result; Based on the initial solution results, if the current electromagnetic interference value Exceeds the corresponding entry in the calibration table ±15%, then enable the marked abnormal data filtering results, remove the disturbed channel data and recalculate. If the ambient temperature change rate is , then add the temperature drift compensation to the solution result , where the compensation coefficient α is measured by pre-calibration experiment; The calculated coordinates after compensation Compare with the preset position threshold: For linear positioning, if , it is determined that the target position has been reached. For rotation positioning, if , then generate the valve in-position control signal.

6. The high-precision positioning system for a water treatment multi-way control valve based on magnetic induction according to claim 1 is characterized in that: During rotational positioning, the magnetic field intensity distribution curve of the initial position of the magnet is identified through a feature matching algorithm and set as the reference zero point; during operation, when it is detected that the correlation coefficient between the current magnetic field intensity distribution curve and the reference zero point drops to the range of 0.92-0.95, the nonlinear compensation program based on the back propagation neural network is automatically triggered to correct the positioning error caused by permanent magnet demagnetization and mechanical deformation.

7. The high-precision positioning system for a water treatment multi-way control valve based on magnetic induction according to claim 1 is characterized in that: For valve core movement with a linear displacement exceeding 200mm, at least three of the aforementioned sensing device units are arranged equidistantly along the direction of movement, and the spacing between adjacent sensor units is 70%-80% of the effective detection range of the sensor. Through sensor relay data fusion, the full-stroke positioning accuracy is maintained within ±0.1mm.

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