Intelligent control method and system for corner type floating ball liquid level transmitter

Abstract

This invention relates to the field of automated instrument control technology, and particularly to an intelligent control method and system for a rotary float level transmitter. The method includes the following steps: calculating the deflection compensation factor at each sampling point; the deflection compensation factor is positively correlated with the elastic modulus and moment of inertia of the connecting rod material, and negatively correlated with the equivalent force-bearing mass and effective lever arm length of the float; calculating the variable torque characteristic operator at the sampling point; the variable torque characteristic operator is positively correlated with the instantaneous angular acceleration of the original angle sequence, and negatively correlated with the absolute value of the sine of the original angle; coupling the original angle, the variable torque characteristic operator, and the deflection compensation factor to obtain the reconstructed level value of the sampling point; and driving the actuator to adjust the flow rate in response to the reconstructed level value of the sampling point exceeding a set threshold, which can effectively improve the control accuracy of the rotary float level transmitter.

Description

Technical Field

[0001] This invention relates to the field of automated instrumentation and control technology, and in particular to an intelligent control method and system for a rotary float level transmitter. Background Technology

[0002] Angle-type float level transmitters typically use a float that rises and falls with the liquid level, driving a connecting rod to rotate. A sensor collects the angular displacement of the rotating shaft, and the internal control system converts the physical angle signal into an actual liquid level signal for output. Due to their relatively simple structure and reliable characteristics such as high pressure and high temperature resistance, these transmitters are used for level monitoring of pressure vessels and large storage tanks in industrial production sites such as petroleum, chemical, and metallurgical industries. The liquid medium environment inside an angle-type float level transmitter is complex, and the equipment operates under heavy load and continuous conditions for extended periods. The accuracy and dynamic stability of the level measurement data directly affect the normal operation of the closed-loop control system and overall production safety.

[0003] However, during operation, as the liquid level rises, the long connecting rod experiences slight physical bending due to the buoyancy of the liquid and its own weight—a process known as elastic deflection. Simultaneously, mechanical friction at the shaft causes sluggish movement during the equipment's ascent and descent. Traditional control methods typically rely on idealized geometric trigonometry to treat the connecting rod as an absolutely rigid body. This approach leads to severe distortion and lag in the transmitter's output liquid level data when using traditional measurement and control technologies. For example, the bending of the connecting rod may result in a systematically higher error, or friction may cause inconsistencies in the actual height at the same angle. This measurement distortion caused by mechanical deformation and friction results in incorrect feedback signals received by the downstream industrial closed-loop control system, preventing the system from accurately determining the current true liquid level rise or fall.

[0004] Therefore, how to accurately control the rotary float level transmitter during use, so as to accurately obtain the true state of liquid level rise and fall, is an urgent problem to be solved. Summary of the Invention

[0005] To address the technical problem of accurately controlling a rotary float level transmitter during use and thus accurately obtaining the true state of liquid level rise and fall, this invention provides an intelligent control method and system for a rotary float level transmitter.

[0006] In a first aspect, the present invention provides an intelligent control method for a rotary float level transmitter, employing the following technical solution: A method for intelligent control of a rotary float level transmitter includes the following steps: The process involves acquiring the original angle sequence of the shaft containing multiple sampling points, as well as the transmitter's hardware parameters, including the elastic modulus of the connecting rod, the moment of inertia of the cross section, the equivalent force-bearing mass of the float, and the effective lever arm length. The deflection compensation factor for each sampling point is calculated; this factor is positively correlated with the elastic modulus and moment of inertia of the connecting rod material, and negatively correlated with the equivalent force-bearing mass and effective lever arm length of the float. A variable torque characteristic operator for each sampling point is also calculated; this operator is positively correlated with the instantaneous angular acceleration of the original angle sequence and negatively correlated with the absolute value of the sine of the original angle. The original angle, variable torque characteristic operator, and deflection compensation factor are coupled to obtain the reconstructed liquid level value of the sampling point. This reconstructed liquid level value is positively correlated with the variable torque characteristic operator and negatively correlated with the deflection compensation factor. In response to the reconstructed liquid level value of the sampling point exceeding a set threshold, the actuator is driven to regulate the flow rate.

[0007] This invention provides an intelligent control method for a corner float level transmitter, which can effectively improve the control accuracy of the corner float level transmitter. In controlling the corner float level transmitter, this invention considers that traditional control methods treat the connecting rod as an absolutely rigid body, which can lead to serious distortion and lag in measurement results, thus affecting control accuracy. Based on this, in level monitoring applications such as pressure vessels and large storage tanks, this invention introduces a deflection compensation factor and a variable torque characteristic operator to effectively eliminate spurious displacements caused by elastic deformation and frictional resistance of the mechanical structure, accurately reconstructing the true level data. This avoids erroneous judgments by the downstream industrial closed-loop control system due to measurement distortion, thereby effectively improving the safety of the production process and the dynamic stability of level control.

[0008] According to the present invention, an intelligent control method for a rotary float level transmitter is provided. The method for acquiring the original angle sequence of the rotating shaft containing multiple sampling points and the hardware parameters of the transmitter includes: using an absolute encoder integrated on the transmitter spindle to capture the original angle sequence of the rotating shaft in real time at a fixed sampling frequency; and reading a pre-stored hardware static reference from the EEPROM inside the control unit, wherein the hardware static reference includes the elastic modulus, moment of inertia of the cross section, equivalent force-bearing mass, and effective lever arm length.

[0009] In complex industrial measurement and control scenarios, this invention constructs a precise physical compensation model observation boundary by sampling and reading a pre-stored hardware static reference at a fixed frequency using an absolute encoder. This effectively prevents the phenomenon of false liquid level jumps caused by reference offset and provides a reliable data foundation for parameter correction in subsequent high-precision liquid level reconstruction.

[0010] According to the present invention, an intelligent control method for a rotary float level transmitter is provided, wherein calculating the deflection compensation factor at each sampling point includes: ; For the first Deflection compensation factor for each sampling point; The elastic modulus of the connecting rod material; Let be the moment of inertia of the connecting rod cross section; For the first The original angle of each sampling point; This is the equivalent mass of the float under stress. It is the acceleration due to gravity; For the first Effective lever arm length of each sampling point; This is a preset center of gravity offset correction constant; It is a cosine function; Used as a reference length.

[0011] This invention provides a precise method for calculating the deflection compensation factor. In industrial environments with drastic fluctuations in liquid levels, it can quantitatively assess the micro-elastic deformation of the connecting rod by combining the material properties of the connecting rod with the transient force characteristics. This allows the false displacement caused by mechanical deformation to be separated from the pure geometric angular displacement, effectively avoiding systematic overestimation errors over a large range.

[0012] According to the present invention, an intelligent control method for a rotary float level transmitter is provided, wherein the variable torque characteristic operator for calculating the sampling point includes: ; , The first Variable torque feature operator for each sampling point, original angle; For the first The sampling point and the first The time variable between sampling points; , The first The sampling point and the first Continuous time domain between sampling points Instantaneous angular acceleration and angle variables, , The first The, the The time variable of each sampling point; The preset environmental viscosity compensation coefficient; It is a sine function; Preset mechanical hysteresis compensation gain; For the first The original angle of each sampling point; To prevent the coefficient from being divided by zero; This is the torque conversion constant; The equivalent radius of rotation; It is an absolute value function.

[0013] This invention provides a precise method for calculating variable torque characteristic operators. Compared with existing digital filtering algorithms, which are unable to distinguish between real liquid level fluctuations and mechanical resistance interference, this invention, under the field conditions of long-term heavy load and friction and wear, obtains the torque component of frictional dissipation through an integral algorithm. It accurately captures and compensates for the extra power consumption required by the float to overcome fluid viscosity and mechanical clearance, and realizes the logical closed-loop elimination of hysteresis phenomenon. Thus, it provides a dynamic compensation benchmark for precise liquid level adjustment in complex damping environments.

[0014] According to the present invention, an intelligent control method for a rotary float level transmitter is provided, wherein the method for obtaining the mechanical hysteresis compensation gain includes: performing bidirectional full-stroke calibration based on the transmitter, controlling the level to rise from 0% to 100% and then returning, extracting the maximum envelope deviation of the angle sampling sequence of the rising segment and the falling segment at the same measurement point, and using the average of the maximum envelope deviation as the mechanical hysteresis compensation gain.

[0015] According to the present invention, an intelligent control method for a rotary float level transmitter is provided, wherein coupling the original angle, the variable torque characteristic operator, and the deflection compensation factor to obtain the reconstructed level value of the sampling point includes: ; , , , The first The reconstructed liquid level value, original angle, variable torque characteristic operator, and deflection compensation factor corresponding to each sampling point; This refers to the transmitter's nominal maximum range. The benchmark calibration coefficients; For An exponential function with base 0.

[0016] According to the present invention, an intelligent control method for a rotary float level transmitter is provided, wherein the drive actuator performs flow regulation, comprising: calculating the rate of change of the reconstructed level value, and combining a variable torque characteristic operator and a deflection compensation factor to obtain the dynamic deviation confidence level of the sampling point; generating a flow regulation command in response to the dynamic deviation confidence level not being greater than a preset confidence threshold; and sending the flow regulation command to the actuator to drive the actuator to adjust the inlet or outlet flow rate so that the level is restored to a safe range.

[0017] This invention provides a method for calculating the dynamic deviation confidence of sampling points. In harsh industrial environments prone to cavitation, particulate matter blockage, or strong electromagnetic interference, it establishes an intelligent hierarchical execution mechanism for control commands, effectively filtering out sudden false jumps caused by non-physical factors. This effectively reduces the possibility of major production safety accidents such as tank overflows or pump dry runs caused by incorrect valve opening and closing.

[0018] According to the present invention, a smart control method for a rotary float level transmitter is provided, wherein obtaining the dynamic deviation confidence level of the sampling point includes: ; , , , The first Dynamic deviation confidence level, reconstructed liquid level value, variable torque characteristic operator, and deflection compensation factor for each sampling point; For the first Reconstructed liquid level values ​​at each sampling point; The system sampling period; The preset system dynamics mapping constant; The preset environmental viscosity compensation coefficient; It is an absolute value function; It is the equivalent area constant.

[0019] According to the present invention, a smart control method for a rotary float level transmitter is provided, wherein the drive actuator performs flow regulation, and further includes: in response to the dynamic deviation confidence level being greater than a preset confidence threshold, determining that the sensor data has a logical break, automatically blocking the control pulse of the actuator and maintaining the safe state of the previous sampling cycle, and issuing a self-diagnostic alarm.

[0020] Secondly, this invention provides an intelligent control system for a rotary float level transmitter, employing the following technical solution: An intelligent control system for a corner float level transmitter includes a processor and a memory. The memory stores computer program instructions, and when the computer program instructions are executed by the processor, the aforementioned intelligent control method for a corner float level transmitter is implemented.

[0021] By adopting the above technical solution, a computer program is generated from the above-mentioned intelligent control method for a rotary float level transmitter, and stored in a memory for loading and execution by a processor. This allows for the creation of a terminal device based on the memory and processor, making it convenient to use.

[0022] The present invention has the following technical effects: Based on the above technical solution, the present invention provides an intelligent control method and system for a rotary float level transmitter. By introducing a deflection compensation factor and a variable torque characteristic operator, the false displacements caused by the elastic deformation and frictional resistance of the mechanical structure are effectively removed, and the true level data is accurately reconstructed. This avoids the back-end industrial closed-loop control system from making incorrect judgments due to measurement distortion, thereby effectively improving the safety of the production process and the dynamic stability of the level control. Attached Figure Description

[0023] Figure 1 This is a flowchart illustrating an intelligent control method for a rotary float level transmitter provided in an embodiment of the present invention. Figure 2 This is a schematic diagram of the force on a connecting rod under low liquid level conditions, provided as an embodiment of the present invention. Figure 3 This is a schematic diagram illustrating the increased deflection of a connecting rod under high liquid level conditions, provided by an embodiment of the present invention. Figure 4 This is a comparison chart of the liquid level measurement effects of the present invention and existing technologies, provided in an embodiment of the present invention. Detailed Implementation

[0024] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments.

[0025] This invention discloses an intelligent control method for a rotary float level transmitter. For details, please refer to [link / reference needed]. Figure 1 As shown, Figure 1 This is a flowchart illustrating an intelligent control method for a rotary float level transmitter provided in an embodiment of the present invention. The method specifically includes the following steps: S1: Obtain the original angle sequence of the shaft containing multiple sampling points, as well as the hardware parameters of the transmitter.

[0026] It should be noted that during the actual sampling process, due to impedance matching issues in the transmission cable, the original voltage signal may be mixed with high-frequency thermal noise. If the high-frequency components are not initially stripped and the material modulus parameters are not obtained simultaneously, the subsequent deflection correction will result in a reference offset, which may lead to false jumps in the output liquid level in severe cases, directly affecting production safety.

[0027] Based on this, embodiments of the present invention can construct the boundary conditions of the subsequent physical compensation model by obtaining accurate hardware static benchmarks.

[0028] For example, in this embodiment of the invention, an absolute encoder integrated on the transmitter spindle can be used to capture the original angle sequence of the shaft in real time at a fixed sampling frequency. A pre-stored hardware static reference is read from the electrically erasable read-only memory inside the control unit. The hardware parameters corresponding to the hardware static reference include the elastic modulus, moment of inertia, equivalent mass under load, and effective lever arm length.

[0029] The fixed sampling frequency can be set to 50Hz, but the specific setting can be adjusted according to actual needs. The moment of inertia and elastic modulus of the connecting rod section are derived from the material manufacturer's quality certificate. The equivalent force mass of the float can be obtained through actual measurement using a high-precision electronic balance. The effective lever arm length is a parameter of the angled float level transmitter itself.

[0030] Please see Figure 2 and Figure 3 As shown, Figure 2 This is a schematic diagram of the force on the connecting rod under low liquid level conditions provided by an embodiment of the present invention. Figure 3 This is a schematic diagram illustrating the increased deflection of a connecting rod under high liquid level conditions, provided as an embodiment of the present invention. In the diagram, solid lines represent actual connecting rods, and dashed lines represent ideal rigid body connecting rods.

[0031] in, Figure 2 This demonstrates the operation of an angle-type float level transmitter in the low liquid level range, where the angle between the connecting rod and the liquid surface is relatively large, and the normal component of the buoyancy force is relatively small. By comparing an actual connecting rod with an ideal rigid body connecting rod, the subtle physical bending, i.e., elastic deflection, that occurs in the connecting rod under these conditions is shown.

[0032] Figure 3 This diagram illustrates the extreme stress conditions experienced by the transmitter when operating in the high liquid level range. As the liquid level rises, the connecting rod tends to become horizontal, and the buoyancy torque reaches its peak, leading to a significant increase in the physical bending of the connecting rod. The solid line in the diagram exhibits a distinct arc-shaped bend, deviating from the ideal geometric trigonometric conversion path.

[0033] Thus, by acquiring the original angle sequence of the rotating shaft and the hardware parameters of the transmitter, the embodiments of the present invention can effectively establish accurate physical model observation boundaries, thereby providing an accurate data foundation for subsequent stripping of mechanical deflection and calculation of variable torque characteristic operators.

[0034] S2: Calculate the deflection compensation factor for each sampling point based on the elastic modulus, moment of inertia of the cross section, equivalent mass of the float under force, and effective lever arm length of the connecting rod material.

[0035] Among them, the deflection compensation factor is positively correlated with the elastic modulus and cross-sectional moment of inertia of the connecting rod material, and negatively correlated with the equivalent force-bearing mass and effective lever arm length of the float.

[0036] It should be noted that deflection refers to the minute displacement caused by the deformation of a bending member in the direction of force. In angular measurement, the connecting rod is not an ideal rigid body. When the liquid level rises, causing an increase in buoyancy torque, the connecting rod will produce an arc-shaped bend away from the liquid surface. If the deflection compensation factor is not calculated, it may be mistakenly assumed that the minute change in the shaft angle is entirely caused by the change in liquid level, resulting in a systematic overestimation error over a large range. Therefore, this embodiment of the invention, by performing real-time calculations for each sampling point, can separate the elastic deformation of the mechanical structure from the geometric displacement.

[0037] Furthermore, according to the basic principles of the standard beam bending theory in mechanics of materials, the bending force of the connecting rod is directly proportional to the load and inversely proportional to the bending stiffness. The bending effect of the float on the connecting rod is not constant but varies with the angle. However, the absolute deflection model given by the standard beam bending theory assumes that the load direction is perpendicular to the beam axis. Based on this, this embodiment of the invention projects the vertical effect of buoyancy onto the normal direction of the connecting rod by introducing the cosine value of the original angle, reflecting the physical characteristic that the load direction changes with the liquid level in the float transmitter. On this basis, the absolute deflection is converted into a dimensionless compensation factor, thereby converting the degree of bending into the degree that needs compensation. In this way, by combining the material stiffness properties and the instantaneous angle, a deflection compensation factor can be constructed to evaluate the deformation component. When the deflection compensation factor is large, it indicates that the bending moment on the connecting rod is small or the material is extremely rigid, and the deformation is almost negligible; when the deflection compensation factor decreases, it indicates that the current sampling angle includes spurious displacement caused by the bending of the rod.

[0038] For example, in an embodiment of the present invention, the relationship for calculating the deflection compensation factor at each sampling point is as follows: ; For the first Deflection compensation factor for each sampling point, dimensionless coefficient; The elastic modulus of the connecting rod material, in units of... ; The moment of inertia of the connecting rod cross section is given by . ; For the first The original angle of each sampling point, in units of ; The equivalent mass of the float under stress, in units of ; Let be the acceleration due to gravity, and take . ; For the first The effective lever arm length of each sampling point varies with the angle, in units of... ; This is a preset center of gravity offset correction constant; It is a cosine function used to characterize the trigonometric mapping of angle change to normal torque; Reference length, in units of .

[0039] The center of gravity offset correction constant is used to correct the offset of the center of gravity. It can be obtained by static balance calibration and has a value range of 0.01 to 0.05. Optionally, in this embodiment of the invention, it can be set to 0.02, and the specific value can be set according to actual needs. The reference length is used for dimension adjustment and can be set to 1.

[0040] In the above formula, the elastic modulus characterizes the material's ability to resist deformation, and the moment of inertia characterizes the geometric resistance of the cross section to bending. Since the higher the stiffness of the connecting rod, the larger the elastic modulus and the moment of inertia of the cross section, the smaller the resulting physical deformation, and therefore the larger the deflection compensation factor, the smaller the deformation effect.

[0041] In a rotary float level transmitter, the buoyancy of the float in water is always vertically upward, while the bending moment generated by the connecting rod depends on the component of the buoyancy in the normal direction of the connecting rod. As the initial angle of the sampling point increases, the connecting rod gradually tends to a horizontal state. As the force decreases, the combined torque of gravity and buoyancy on the connecting rod increases, resulting in severe deformation and a smaller corresponding deflection compensation factor.

[0042] This is the load and lever arm term, used to characterize the destructive bending moment acting on the link. Due to the equivalent mass... and effective lever arm length The larger the value, the greater the bending moment generated by the gravity and buoyancy, which leads to a greater degree of bending of the mechanical rod. Therefore, the calculated deflection compensation factor will decrease, thus characterizing the enhanced deformation effect.

[0043] Thus, by combining the material properties of the connecting rod with the transient force characteristics to calculate the deflection compensation factor, the embodiment of the present invention can effectively eliminate the spatial displacement error caused by the deformation of the mechanical structure, thereby providing accurate correction parameters for subsequent high-precision liquid level reconstruction.

[0044] S3: Calculate the variable torque characteristic operator of the sampling point based on the instantaneous angular acceleration of the original angle sequence and the original angle.

[0045] Among them, the variable torque characteristic operator is positively correlated with the instantaneous angular acceleration of the original angle sequence and negatively correlated with the absolute value of the sine of the original angle.

[0046] It should be noted that the embodiments of the present invention need to address the hysteresis problem during mechanical rotation. Physical bearings inevitably undergo a conversion from static friction to dynamic friction during rotation. Hysteresis refers to the difference in actual height between the same angle and the same angle of the float during the liquid level rise and fall processes due to mechanical clearance and frictional resistance. Without calculating the variable torque characteristic operator, the control system cannot identify whether the float is in a state of rising stagnation or falling hysteresis, thus forming a severe hysteresis loop on the output curve, leading to low-frequency oscillations in industrial closed-loop control. Existing digital filtering algorithms struggle to distinguish between actual liquid level fluctuations and interference caused by mechanical deformation, resulting in a tradeoff between the transmitter's dynamic response performance and steady-state accuracy.

[0047] Understandably, the standard rotational dynamics equations can be applied to transmitters, where the driving torque originates from the buoyancy change caused by the liquid level change and is transmitted to the shaft through the float-linkage system; the moment of inertia includes the total moment of inertia of the float, link, and shaft; the angular acceleration is obtained by the second derivative of the angle sequence by the encoder; the frictional torque originates from the viscous friction of bearings, seals, etc.; and the static frictional torque originates from the static friction jump and mechanical clearance when the direction of motion changes.

[0048] However, during transmitter operation, the driving torque cannot be directly obtained, the frictional torque is unobservable, and the standard equation only describes the torque balance relationship, which cannot distinguish between frictional dissipation and normal fluctuations in liquid level.

[0049] Based on this, embodiments of the present invention can avoid directly using the torque balance equation. Instead, they can deduce friction dissipation by integrating angular acceleration. According to Coulomb's law of friction, frictional force is proportional to normal force. Therefore, the same angular acceleration results in greater frictional dissipation at a vertical position. Furthermore, embodiments of the present invention introduce an angle difference term, which can transform static friction jumps that are difficult to handle in the standard equations into a continuous compensation function proportional to the angle change.

[0050] The work done by friction consumes the component of liquid potential energy that is converted into rotational kinetic energy. By integrating the angular acceleration between sampling points over time, the torque component dissipated by friction can be derived in reverse. Based on this, a variable torque characteristic operator can be constructed to characterize the difficulty of the buoy overcoming resistance when rotating in water.

[0051] For example, in an embodiment of the present invention, the relational formula for calculating the variable torque characteristic operator of the sampling point is as follows: ; in, For the first The variable torque characteristic operator for each sampling point, in units of ; For the first The original angle of each sampling point, in units of ; For the first The sampling point and the first The time variable between sampling points, in units of ; For the first The sampling point and the first Continuous time domain between sampling points Instantaneous angular acceleration, in units of ; , The first The, the The time variable of each sampling point; For the first The sampling point and the first Continuous time domain between sampling points Angle variable, unit is ; It is a sine function; For the first The original angle of each sampling point, in units of ; This is the torque conversion constant, in units of... ; The equivalent radius of rotation is given in units of 1 / 2. ; It is an absolute value function.

[0052] in, The preset environmental viscosity compensation coefficient is in units of... It is used to compensate for fluid viscous resistance and is determined by the physicochemical parameters of the medium, with a value range of 0.01 to 0.1; optionally, in the embodiments of the present invention, it can be set to 0.05, and can be set according to actual needs.

[0053] in, A preset mechanical hysteresis compensation gain is used to compensate for mechanical clearance. The mechanical hysteresis compensation gain is obtained by: performing bidirectional full-stroke calibration based on the transmitter, controlling the liquid level to rise from 0% to 100% and then returning, extracting the maximum envelope deviation of the angle sampling sequences of the rising and falling segments at the same measurement point, and using the average of the maximum envelope deviations as the mechanical hysteresis compensation gain. Optionally, in this embodiment of the invention, it can be set to 0.1, and the specific value can be set according to actual needs.

[0054] in, To prevent the denominator from being zero, the coefficient is used to prevent the absolute value from being zero. Its value range is from 0.001 to 0.05. Optionally, in the embodiments of the present invention, it can be set to 0.01, and the specific value can be set according to actual needs.

[0055] The torque conversion constant is used to adjust the dimensions and can be set to 1, but the specific setting can be adjusted according to actual needs. The equivalent radius of rotation can be obtained through dynamic calibration, which will not be elaborated here in this embodiment of the invention.

[0056] In the above relationship, acceleration is a result of torque. In a system with friction, the actual acceleration reflects the remaining effectiveness of the driving torque after overcoming the resisting torque. The higher the intensity of motion, the greater the instantaneous angular acceleration. The larger the value, the higher the dynamic frictional dissipation that needs to be compensated, and therefore the larger the calculated variable torque characteristic operator. This represents the equivalent cumulative torque power consumed by the float to overcome fluid viscous resistance and mechanical bearing friction within an extremely short sampling interval. The time interval between them is called the sampling interval.

[0057] Variable torque characteristic operator on the left side of the equals sign It is negatively correlated with the sine function in the denominator on the right. Since the sine value decreases as the angle approaches a horizontal position, the value on the right side of the equation increases. The increase reflects the physical logic that gravitational torque is most sensitive to friction during horizontal displacement.

[0058] It is the angle difference term, used to characterize the mechanical transmission chain in the first... Directional gap compensation for each sampling interval. This term utilizes the angle difference between the current and previous moments, combined with hysteresis gain, to generate static position compensation. When the liquid level rises, causing the angle difference term to become positive, Increase it to overcome the resistance to upward movement; conversely, decrease it, thereby eliminating the mechanical hysteresis logic loop on both sides of the equal sign.

[0059] Thus, by constructing a variable torque characteristic operator based on energy dissipation, the embodiments of the present invention can effectively evaluate and offset frictional losses caused by mechanical clearance and fluid viscosity, thereby providing a dynamic compensation benchmark for liquid level reconstruction.

[0060] S4: Couple the original angle, variable torque characteristic operator and deflection compensation factor to obtain the reconstructed liquid level value of the sampling point.

[0061] Among them, the reconstructed liquid level value is positively correlated with the variable torque characteristic operator and negatively correlated with the deflection compensation factor.

[0062] It should be noted that this step is crucial in converting the previously extracted physical correction factor into the final output signal. Without reconstruction mapping, severe systematic errors will occur in the output result due to the drastic changes in the radial component of buoyancy at the high and low ranges. This embodiment of the invention ensures linearity across the entire range by nonlinearly coupling the deflection compensation factor with the variable torque characteristic operator.

[0063] Furthermore, the microscopic deformation and hysteresis effects in mechanical systems usually follow a nonlinear convergence law. By introducing the quotient of the variable torque characteristic operator and the deflection compensation factor as an exponential term, the weight of the angle under different force states can be dynamically adjusted to realize the transformation from angle space to linear height space.

[0064] For example, in an embodiment of the present invention, the relationship for calculating the reconstructed liquid level value is as follows: ; For the first Reconstructed liquid level values ​​at each sampling point, in units of ; For the first The original angle of each sampling point, in units of Its dimension is 1; For the first The variable torque characteristic operator for each sampling point, in units of ; For the first The deflection compensation factor for each sampling point is dimensionless. The transmitter's nominal maximum range, in units of ; For An exponential function with base is used to achieve nonlinear smooth convergence from the data space to the physical space.

[0065] in, These are the benchmark calibration coefficients, used to achieve dimensional alignment and control the convergence speed of the mapping curve; the unit is . The value ranges from 0.001 to 0.1; optionally, in this embodiment of the invention, it can be set to 0.01, and can be set according to actual needs.

[0066] In the above relationship, the variable torque characteristic operator represents the additional energy required to overcome friction and hysteresis. The variable torque characteristic operator is affected by the increased frictional dissipation. As the level rises, the absolute value within the exponential term increases, causing the value of the exponential function to decrease. This results in an overall increase in the value within the square brackets, thus affecting the reconstructed liquid level value. Increase the level to compensate for the underestimation of liquid level caused by hysteresis.

[0067] Deflection compensation factor for reconstructed liquid level value and denominator position A negative correlation is observed: the smaller the deflection compensation factor, the greater the upward bending deformation of the connecting rod due to buoyancy, and the lower its rigidity. Therefore, when the connecting rod bends under stress, leading to a decrease in rigidity... When the value decreases, the reconstructed liquid level increases to compensate for the lower error caused by the deflection deformation.

[0068] In a rotary measurement system, the hysteresis effect caused by mechanical backlash and the deformation effect generated by the elasticity of the connecting rod are intertwined and nonlinearly distributed. By ratioing the dynamic power consumption component of the numerator to the structural stiffness component of the denominator, the reconstructed liquid level value can automatically adjust the mapping weights according to the current mechanical load state. Thus, this embodiment of the invention, by constructing a multidimensional variable nonlinear coupling mapping, can effectively offset the radial component abrupt disturbance under extreme operating conditions, thereby outputting extremely high-precision liquid level height data to the industrial control center.

[0069] S5: In response to the reconstructed liquid level value at the sampling point exceeding the set threshold, the actuator is driven to adjust the flow rate.

[0070] The threshold can be set to 85% of the transmitter's nominal maximum range, and can be set according to the actual height of the storage tank and the flange installation position. This embodiment of the invention does not impose too many restrictions here.

[0071] Based on the above steps, the actuator can be driven to achieve flow regulation.

[0072] It should be noted that this step converts the calculated liquid level data into industrial control commands. The actuator refers to the controlled pump, frequency converter, or alarm linkage device. In complex industrial environments, sensors may produce sudden, false jumps due to cavitation, particulate matter blockage, or strong electromagnetic pulses. If data logic is not performed to review the data, and the equipment is adjusted directly based on the comparison between the reconstructed liquid level value from the sampling point and the set threshold, the system may mistakenly believe the liquid level is full and close the valve. This erroneous liquid level data will be directly transmitted to the downstream system, potentially causing serious safety accidents such as tank overflow or pump dry running.

[0073] Therefore, in the embodiments of the present invention, when driving the actuator to regulate flow, an evaluation mechanism based on physical conservation consistency can be established, and the weight of control command execution can be determined by calculating the confidence level of dynamic deviation, thereby realizing intelligent hierarchical push of control commands and system self-diagnosis.

[0074] For example, in an embodiment of the present invention, driving the actuator to perform flow regulation includes: calculating the rate of change of the reconstructed liquid level value, and combining the variable torque characteristic operator and the deflection compensation factor to obtain the dynamic deviation confidence level of the sampling point.

[0075] Furthermore, according to the principle of energy conservation, the rate of change of liquid level matches the work done by the driving torque in the system. In a float-type level transmitter, the driving torque originates from the change in buoyancy caused by the change in liquid level, and this torque has a definite physical relationship with the velocity of the float, the viscous resistance of the fluid, and the inertia of the mechanical system.

[0076] Based on this, embodiments of the present invention can deduce the theoretical rate of liquid level change based on a mechanical model to assess the expected rate of liquid level change. The absolute value of the deviation between the actual measured rate and the theoretically calculated rate is obtained. When the deviation is small, it indicates that the observed liquid level change conforms to the expectations of the mechanical model, and the data reliability is high. When the deviation is large, it indicates that there are components in the actual measured signal that do not conform to physical laws, such as sensor malfunction, electromagnetic interference, cavitation, etc., and the data reliability is low.

[0077] For example, in an embodiment of the present invention, the relationship for calculating the confidence level of dynamic bias is as follows: ; For the first The dynamic bias confidence level for each sampling point, in units of ; For the first Reconstructed liquid level values ​​at each sampling point, in units of ; For the first Reconstructed liquid level values ​​at each sampling point, in units of ; The system sampling period is expressed in units of 1 / 2. ; For the first The variable torque characteristic operator for each sampling point, in units of ; For the first The deflection compensation factor for each sampling point is dimensionless. The preset environmental viscosity compensation coefficient is in units of... ; This is an absolute value function used to extract the net deviation magnitude of two-way fluctuations; This is the equivalent area constant, in units of... .

[0078] in, The preset system dynamics mapping constant is used to map the system dynamics characteristics. It is obtained based on dynamic load experimental calibration and has a value range of 0.01 to 0.1. Optionally, in this embodiment of the invention, it can be set to 0.05, and can be set according to actual needs.

[0079] The system sampling period can be set to The specific settings can be configured according to actual needs.

[0080] Among them, the equivalent force-bearing area constant characterizes the force-bearing cross-sectional characteristics of the float assembly when it moves in the fluid. It is used to normalize the dynamic torque component to the linear velocity dimension in the confidence calculation. It can be obtained by measuring the torque after a constant speed drive experiment in the experimental calibration method. The embodiments of the present invention will not be described in detail here.

[0081] In the above relation, It is the actual rate of change of liquid level. This is the theoretical rate of change of liquid level. Dynamic deviation confidence level. It depends on the absolute value of the difference between the observed actual rate of change of liquid level and the theoretical rate of change derived from the mechanical model. The smaller the absolute value of the difference, the more it indicates that the current electrical signal conforms to the laws of fluid dynamics, and the system determines that the data is true and reliable. If the absolute value of the difference is too large and exceeds the preset threshold, it indicates that the apparent rate of change of liquid level has deviated from the physical constraints of damping and deformation, triggering the automatic blocking mechanism.

[0082] Figure 4 This is a comparison chart of the liquid level measurement effects of the present invention and the prior art, provided as an embodiment of the present invention. It includes the actual liquid level value, the measurement value of the traditional method, and the reconstructed value of the present invention.

[0083] As can be seen, in the rising segment on the left, the dashed line of the existing technology is significantly higher than the true value, demonstrating the high systematic deviation caused by neglecting the bending of the connecting rod in the traditional technology. At the peak of the wave, the dashed line shows a significant hysteresis error. This is due to the switching of static friction force generated by the mechanical rotation hysteresis, causing the float to fail to respond immediately to the drop in liquid level, thus creating a measurement dead zone.

[0084] The solid line corresponding to the present invention shows that the reconstructed liquid level is highly coincident with the actual liquid level line, indicating that the bending error is reduced by the deflection compensation factor, and the mechanical hysteresis and frictional hindrance are compensated by the variable torque characteristic operator, resulting in a sensitive response at the moment of commutation and effectively reducing the hysteresis loop.

[0085] For example, in this embodiment of the invention, in response to the dynamic deviation confidence level not being greater than a preset confidence threshold, a flow regulation command is generated; the flow regulation command is sent to the actuator to drive the actuator to adjust the inlet or outlet flow rate so that the liquid level is restored to a safe range. In response to the dynamic deviation confidence level being greater than the preset confidence threshold, it is determined that a logical break has occurred in the sensor data, the control pulse of the actuator is automatically blocked and the safe state of the previous sampling cycle is maintained, while a self-diagnostic alarm is issued.

[0086] In this embodiment, the preset confidence threshold is used to determine whether a logical break has occurred in the data, and it can be obtained using a statistical probability distribution method. Specifically, during the equipment's factory commissioning phase, 1000 consecutive sets of dynamic deviation confidence data can be extracted under steady-state operating conditions, their standard deviation can be calculated, and the preset confidence threshold can be set to three times the standard deviation. This ensures that the actuator will not frequently adjust due to normal system noise, while also guaranteeing that the system can lock into the previous safe state when faced with genuine sudden interference, thus ensuring the inherent safety of the industrial site.

[0087] Thus, by constructing a dynamic verification model that couples multiple physical quantities, the embodiments of the present invention can effectively identify and filter out sudden false jumps in sensors, thereby improving the decision reliability of the control system under extreme conditions.

[0088] This invention also discloses an intelligent control system for a corner float level transmitter, including a processor and a memory. The memory stores computer program instructions, and when the computer program instructions are executed by the processor, an intelligent control method for a corner float level transmitter provided by this invention is implemented.

[0089] The system also includes other components well known to those skilled in the art, such as communication buses and communication interfaces, the settings and functions of which are known in the art and will not be described in detail here.

[0090] In this invention, the aforementioned memory can be any tangible medium that contains or stores a program that can be used by or in conjunction with an instruction execution system, apparatus, or device.

[0091] The above are all preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A smart control method for a rotary float level transmitter, characterized in that, include: Obtain the original angle sequence of the shaft containing multiple sampling points, as well as the hardware parameters of the transmitter, including the elastic modulus of the connecting rod, the moment of inertia of the section, the equivalent force mass of the float, and the effective lever arm length; Calculate the deflection compensation factor at each sampling point. The deflection compensation factor is positively correlated with the elastic modulus and moment of inertia of the connecting rod material, and negatively correlated with the equivalent mass of the float and the effective lever arm length. The variable torque feature operator of the sampling point is calculated. The variable torque feature operator is positively correlated with the instantaneous angular acceleration of the original angle sequence and negatively correlated with the absolute value of the sine of the original angle. The original angle, the variable torque feature operator, and the deflection compensation factor are coupled to obtain the reconstructed liquid level value of the sampling point. The reconstructed liquid level value is positively correlated with the variable torque feature operator and negatively correlated with the deflection compensation factor. In response to the reconstructed liquid level value at the sampling point exceeding the set threshold, the actuator is driven to adjust the flow rate.

2. The intelligent control method for a rotary float level transmitter according to claim 1, characterized in that, The acquisition of the original angle sequence of the rotating shaft containing multiple sampling points, and the hardware parameters of the transmitter, includes: An absolute encoder integrated on the transmitter spindle is used to capture the original angle sequence of the shaft in real time at a fixed sampling frequency; a pre-stored hardware static reference is read from the EEPROM inside the control unit, which includes the elastic modulus, moment of inertia of the section, equivalent force mass and effective lever arm length.

3. The intelligent control method for a rotary float level transmitter according to claim 1, characterized in that, The calculation of the deflection compensation factor for each sampling point includes: ； For the first Deflection compensation factor for each sampling point; The elastic modulus of the connecting rod material; Let be the moment of inertia of the connecting rod cross section; For the first The original angle of each sampling point; This is the equivalent mass of the float under stress. It is the acceleration due to gravity; For the first Effective lever arm length of each sampling point; This is a preset center of gravity offset correction constant; It is a cosine function; Used as a reference length.

4. The intelligent control method for a rotary float level transmitter according to claim 1, characterized in that, The variable torque feature operator for calculating the sampling points includes: ； , The first Variable torque feature operator for each sampling point, original angle; For the first The sampling point and the first The time variable between sampling points; , The first The sampling point and the first Continuous time domain between sampling points Instantaneous angular acceleration and angle variables, , The first The, the The time variable of each sampling point; The preset environmental viscosity compensation coefficient; It is a sine function; Preset mechanical hysteresis compensation gain; For the first The original angle of each sampling point; To prevent the coefficient from being divided by zero; This is the torque conversion constant; The equivalent radius of rotation; It is an absolute value function.

5. The intelligent control method for a rotary float level transmitter according to claim 4, characterized in that, Methods for obtaining mechanical hysteresis compensation gain include: Based on the transmitter, bidirectional full-stroke calibration is performed. The liquid level is controlled to rise from 0% to 100% and then return. The maximum envelope deviation of the angle sampling sequence of the rising and falling segments at the same measurement point is extracted, and the average value of the maximum envelope deviation is used as the mechanical hysteresis compensation gain.

6. The intelligent control method for a rotary float level transmitter according to claim 1, characterized in that, The process of coupling the original angle, the variable torque feature operator, and the deflection compensation factor to obtain the reconstructed liquid level value of the sampling point includes: ； , , , The first The reconstructed liquid level value, original angle, variable torque characteristic operator, and deflection compensation factor corresponding to each sampling point; This refers to the transmitter's nominal maximum range. The benchmark calibration coefficients; For An exponential function with base 0.

7. The intelligent control method for a rotary float level transmitter according to claim 1, characterized in that, The drive actuator performs flow regulation, including: The rate of change of the reconstructed liquid level is calculated, and the dynamic deviation confidence level of the sampling point is obtained by combining the variable torque characteristic operator and the deflection compensation factor. In response to the dynamic deviation confidence level not being greater than a preset confidence threshold, a flow regulation command is generated. The flow regulation command is sent to the actuator to drive the actuator to adjust the inlet or outlet flow rate so that the liquid level is restored to a safe range.

8. The intelligent control method for a rotary float level transmitter according to claim 7, characterized in that, The obtained dynamic deviation confidence level of the sampling points includes: ； , , , The first Dynamic deviation confidence level, reconstructed liquid level value, variable torque characteristic operator, and deflection compensation factor for each sampling point; For the first Reconstructed liquid level values ​​at each sampling point; The system sampling period; The preset system dynamics mapping constant; The preset environmental viscosity compensation coefficient; It is an absolute value function; It is the equivalent area constant.

9. The intelligent control method for a rotary float level transmitter according to claim 7, characterized in that, The drive actuator for flow regulation also includes: In response to the dynamic deviation confidence level being greater than a preset confidence threshold, it is determined that the sensor data has experienced a logical break, the control pulse of the actuator is automatically blocked and the safe state of the previous sampling cycle is maintained, and a self-diagnostic alarm is issued at the same time.

10. An intelligent control system for a rotary float level transmitter, characterized in that, include: The processor and memory, wherein the memory stores computer program instructions, which, when executed by the processor, implement the intelligent control method for a rotary float level transmitter according to any one of claims 1-9.

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