A hydraulic dam intelligent control method based on finite element analysis

Abstract

The application belongs to the technical field of hydraulic engineering, and particularly relates to a hydraulic dam intelligent control method based on finite element analysis, which comprises the following steps: S1, real-time acquisition of key data parameters: real-time acquisition of four types of key data parameters of hydraulic load parameters, structural response parameters, hydraulic system parameters and environment and operation parameters according to a preset acquisition frequency, and uploading of the acquired key data parameters to a background system; S2, finite element analysis: the background system calls a finite element analysis engine to carry out parameterized finite element analysis. The hydraulic dam intelligent control method based on finite element analysis realizes multi-threshold safety judgment based on actual stress, deformation, support reaction force and contact pressure by means of real-time analysis of dam body stress, deformation, support reaction force and contact pressure through parameterized finite elements, effectively avoids structural overload, and significantly improves safety.

Description

Technical Field

[0001] This invention relates to the field of water conservancy engineering technology, and in particular to an intelligent control method for hydraulic dams based on finite element analysis. Background Technology

[0002] Hydraulic dams, as a new type of water-retaining and water-discharging structure, are widely used in engineering scenarios such as river flood control, ecological landscape, and irrigation water storage.

[0003] However, existing hydraulic dam control methods mostly rely on manual setting or simple water level threshold triggering, without using parametric finite element dynamic simulation. This makes it difficult to adapt to complex working conditions where water level, flow velocity, and inclination angle change in real time. It is also impossible to control the dam structure in conjunction with its actual stress state, which can easily lead to safety hazards such as stress concentration, excessive deformation, and hydraulic cylinder overload. Furthermore, it is impossible to achieve integrated real-time analysis and decision-making of load, structural response, and hydraulic system, resulting in insufficient intelligence and safety. In addition, it cannot actively remove foreign objects, which can easily lead to dam surface damage or hydraulic cylinder overload.

[0004] Therefore, this application proposes an intelligent control method for hydraulic dams based on finite element analysis. Summary of the Invention

[0005] Based on the aforementioned technical problems, this invention proposes an intelligent control method for hydraulic dams based on finite element analysis.

[0006] This invention proposes an intelligent control method for hydraulic dams based on finite element analysis, comprising the following steps:

[0007] S1. Real-time acquisition of key data parameters: The system collects four types of key data parameters in real time according to the preset frequency: hydraulic load parameters, structural response parameters, hydraulic system parameters, and environmental and operational parameters. The collected key data parameters are then uploaded to the backend system.

[0008] S2. Finite Element Analysis: The background system calls the finite element analysis engine to perform parametric finite element analysis, specifically including:

[0009] A1. Establish a parametric finite element model: Based on the design parameters of the hydraulic dam, a finite element model including geometric dimensions, material properties and boundary conditions is established in advance. The finite element model uses the dam surface inclination angle as the driving parameter, and the mesh attitude and element orientation are dynamically and adaptively adjusted in real time by rotating the mesh coordinates, and the element stiffness matrix is ​​updated synchronously.

[0010] A2. Real-time equivalent load application: The collected hydraulic load parameters are converted into the total water pressure of the superposition of hydrostatic pressure and dynamic water pressure. The total water pressure is mapped into the nodal force of the dam surface element in a uniform distribution manner. At the same time, the self-weight of the dam body is converted into nodal force as a volume force and applied to the finite element model simultaneously.

[0011] A3. Solution and Result Extraction: The implicit statics solver is used to solve the overall equilibrium equations. Based on the displacement results, combined with the strain-displacement relationship and stress-strain relationship, post-processing calculations are performed to extract the maximum equivalent stress and corresponding position of each dam surface, the maximum normal deformation, the support reaction force of each hydraulic cylinder hinge point, and the contact pressure of adjacent dam surfaces.

[0012] A4. Threshold Comparison and Grading: The equivalent stress, normal deformation, hydraulic cylinder hinge point support reaction force, and dam surface contact pressure obtained from the finite element solution are compared with their respective preset safety thresholds to classify safety levels and calculate the comprehensive safety factor.

[0013] S3. Comprehensive decision-making: Combining the finite element classification results, comprehensive safety factor, and river water level and flow scheduling target, comprehensively determine whether to execute the hydraulic dam lifting action, and determine the target inclination angle, target flow rate, and flow velocity of each dam face.

[0014] S4. Hydraulic system coordinated and precise control: Each dam face has an independent solenoid valve. The opening of the corresponding solenoid valve is independently adjusted based on the deviation between the actual tilt angle and the target tilt angle of each dam face as the control input. At the same time, according to the total flow demand of all dam faces to be operated and the comprehensive safety margin of finite element feedback, the output power of the variable frequency motor is dynamically adjusted to match the output power of the hydraulic pump, so as to realize the synchronous and precise movement of multiple dam faces.

[0015] Preferably, in S1, the hydraulic load parameters include upstream water level, downstream water level, water depth in front of the dam, water depth behind the dam, and flow velocity across the dam.

[0016] The structural response parameters include the inclination angle of each dam face, the surface strain of each dam face along the height direction, the bending moment at the root of each dam face, and the gap displacement between adjacent dam faces.

[0017] The hydraulic system parameters include the rod chamber pressure and rodless chamber pressure of each hydraulic cylinder, the piston rod extension displacement of each hydraulic cylinder, the hydraulic pump outlet pressure, the hydraulic pump output flow rate, the valve core position feedback of each solenoid valve, the hydraulic oil temperature, and the variable frequency motor current and output power.

[0018] The environmental and operational parameters include river water temperature, floating debris density index, and dam vibration acceleration.

[0019] Preferably, in A1, the geometric dimensions include the length, width, thickness, and hinge point position of each dam face;

[0020] The material properties include elastic modulus, Poisson's ratio, density, and yield strength;

[0021] The boundary conditions include the constraints of the hinged support at the bottom of the dam body, the lateral water-stopping displacement constraints, and the contact between adjacent dam faces.

[0022] Preferably, in step A2, the collected upstream and downstream water level data are converted into hydrostatic pressure loads distributed along the dam face, using the following formula: ,in, For hydrostatic pressure, For fluid density, It is the acceleration due to gravity. The depth perpendicularly downwards from the fluid surface;

[0023] The dynamic water pressure load is calculated based on the flow velocity over the dam using the following formula: ,in, For dynamic water pressure, This is the empirical dynamic pressure coefficient. The velocity of the flow over the dam.

[0024] The total water pressure is obtained by vector superposition of the hydrostatic pressure and the hydrodynamic pressure, using the following formula: ,in, The total water pressure is mapped as a uniformly distributed surface load into nodal forces of the dam surface elements. At the same time, the dam body's self-weight is converted into nodal forces as volume forces and applied synchronously to the finite element model.

[0025] Preferably, in A3, the overall equilibrium equation is composed of the overall stiffness matrix of the hydraulic dam, the nodal displacement vector, and the equivalent nodal force vector. The overall stiffness matrix is ​​assembled from the stiffness matrices of each unit and is updated in real time with the inclination angle of the dam surface. The unit strain and stress are obtained through displacement post-processing, thereby determining the maximum equivalent stress, the maximum support reaction force at the hydraulic cylinder hinge point, the maximum normal deformation of the dam surface, and the maximum contact pressure between adjacent dam surfaces.

[0026] Overall equilibrium equation: ,in, The overall stiffness matrix of the hydraulic dam is assembled from the stiffness matrices of individual elements and is updated as the dam face inclination angle changes. Let be the displacement vector for all nodes. This is the equivalent nodal force vector.

[0027] Element stiffness matrix: ,in, The element stiffness matrix, The strain-displacement matrix is... The elastic constitutive matrix is ​​determined by the elastic modulus and Poisson's ratio. for transpose, For the volume domain of the element.

[0028] Strain-displacement relationship: ,in, Let S be the strain vector at a point within the element. This represents the displacement vector of all nodes in this element.

[0029] Stress-strain relationship: ,in, This represents the stress vector at a point within the element.

[0030] Equivalent stress: ,in, For equivalent stress, , , These are the first principal stress, the second principal stress, and the third principal stress, respectively. The maximum value is selected. As .

[0031] Support reaction calculation: ,in, The maximum value is taken as the support reaction vector at the constraint node. As .

[0032] Normal deformation: ,in, For the transformation of the Dharma form, and Let be the displacement vector in three-dimensional space. , , for Components in the x-axis, y-axis, and z-axis directions. , , for The components along the x, y, and z axes are selected based on their maximum values. As .

[0033] Contact pressure between adjacent dam faces: , ,in, For normal contact force, For contact stiffness, For penetration depth, To contact pressure, For the contact area, take the maximum value. As .

[0034] Preferably, the security level classification method in A4 is as follows:

[0035] Compare the maximum equivalent stress on each face of the hydraulic dam with the material yield strength:

[0036] when It was then a green safe zone, in which, This represents the yield strength of the material.

[0037] when It is currently a yellow alert zone.

[0038] when It is currently an orange danger zone.

[0039] when It was then a red emergency zone.

[0040] Compare the maximum support reaction force at the hinge point of each hydraulic cylinder with the maximum allowable support reaction force designed for that hydraulic cylinder:

[0041] when At that time, it was determined to be a green safe zone, in which, This is the maximum permissible support reaction force of the hydraulic cylinder.

[0042] when At that time, it was determined to be a yellow alert zone.

[0043] when At that time, it was identified as an orange danger zone.

[0044] The maximum contact pressure between adjacent dam faces extracted by finite element analysis is compared with the preset allowable contact pressure:

[0045] when At that time, it was determined to be a green safe zone, in which, This is the preset contact pressure.

[0046] when At that time, it was determined to be a yellow alert zone.

[0047] when At that time, it was identified as an orange danger zone.

[0048] Compare the maximum normal deformation of each dam face with the allowable deflection:

[0049] when At that time, it was determined to be a green safe zone, in which, This represents the allowable deflection of the dam surface.

[0050] when At that time, it was determined to be a yellow alert zone.

[0051] when At that time, it was determined to be an orange danger zone.

[0052] when At that time, it was designated as a red emergency zone.

[0053] Calculate the overall safety factor: ,in, This is for the safety factor.

[0054] Preferably, the comprehensive decision-making process in S3 includes:

[0055] When any dam face is in the orange danger zone or the red emergency zone, a dam lowering command is forcibly issued and all dam raising commands are locked.

[0056] Raising the dam is prohibited when any dam face is in a yellow warning zone and the current water level is higher than the flood limit level.

[0057] Raising or lowering the dam is permitted when all dam faces are in the green safety zone and the dam's posture needs to be adjusted according to the water level-flow scheduling rules.

[0058] The target inclination angle is determined as follows: the theoretical target inclination angle of each dam face is calculated back based on the target flow rate, and then the theoretical target inclination angle is substituted back into the finite element model for pre-simulation. If the pre-simulation stress exceeds the limit, the target inclination angle is reduced or step-by-step adjustment is adopted.

[0059] Preferably, in step S4, the deviation between the actual inclination angle and the target inclination angle of each dam face is used as the input of the PID controller, and the output PWM signal controls the opening degree of the solenoid valve core, as shown in the formula: ,in, For the first The error value of each dam surface, For the first The target inclination angle value of the dam face. For the first The actual measured inclination angle of each dam face.

[0060] The PID parameters are dynamically adjusted based on the support reaction force of the hydraulic cylinders on each dam face obtained from finite element analysis. The larger the load, the larger the proportional coefficient. At the same time, the inclination angle difference between adjacent dam faces is monitored in real time. When the inclination angle difference exceeds the set threshold, the opening priority of each solenoid valve is automatically adjusted to maintain synchronization.

[0061] The following calculations are used to adjust the output power of a variable frequency motor:

[0062] Total demand flow: ,in, This represents the total flow required for the dam to be in operation. The effective working area of ​​the hydraulic cylinder. The target speed.

[0063] Power required for hydraulic pump: ,in, The hydraulic power required by the hydraulic pump. This refers to the fluid pressure output by the hydraulic pump.

[0064] Motor drive frequency: ,in, This refers to the motor drive frequency that the inverter needs to output. This refers to the operating frequency of the motor at its rated power. This refers to the rated power of the motor. For overall efficiency.

[0065] The required power of the hydraulic pump is calculated based on the total demand flow rate of the dam surface and the output pressure of the hydraulic pump. The drive frequency of the variable frequency motor is determined by combining the rated parameters of the motor and the overall efficiency of the system. When the comprehensive safety factor is lower than the preset threshold, the upper limit of the hydraulic pump power is reduced proportionally to constrain the dam's movement speed and lifting amplitude.

[0066] The present invention proposes an intelligent control method for hydraulic dams based on finite element analysis, which further includes an anti-jamming mechanism. The anti-jamming mechanism includes miniature hydraulic cylinders and support rods arranged in a rectangular array near the gap between two adjacent dam surfaces. A connecting plate is fixedly sleeved on one end of the piston rod of the miniature hydraulic cylinder. The inner wall of the connecting plate is slidably engaged with the surface of the support rod. A striking hammer is fixedly connected to the side of the connecting plate near the dam surface. A limiting plate is fixedly sleeved on the handle of the striking hammer. The inner wall of the limiting plate is slidably engaged with the surface of the support rod.

[0067] With the above technical solution, when the contact pressure between adjacent dam surfaces exceeds the limit, it is determined that floating objects or stones are stuck in the gap between adjacent dam surfaces. The extension and retraction of the piston rod of the micro hydraulic cylinder drives the connecting plate connected to it to move along the surface of the support rod. At the same time, the movement of the connecting plate drives the hammer to apply a brief directional impact force to the dam surface, shaking off the foreign objects. The limiting plate supports the hammer, which facilitates the directional movement of the hammer.

[0068] Preferably, an elastic sealing strip is embedded between the gaps of two adjacent dam surfaces, and a flow guiding groove is provided.

[0069] Through the above technical solution, the elastic sealing strip has the dual functions of flexible sealing and initial foreign object prevention. Non-large hard foreign objects are blocked outside the gap. When water carries small foreign objects into the gap area, the guide channel changes the local water flow streamline and uses water force to guide the foreign objects to the outside of the gap instead of pushing them into the depth of the gap, effectively reducing the embedding of foreign objects.

[0070] The beneficial effects of this invention are as follows:

[0071] 1. By using parametric finite element analysis to analyze the dam body stress, deformation, support reaction force, and contact pressure in real time, a multi-threshold safety determination based on actual stress, deformation, support reaction force, and contact pressure can be achieved, effectively avoiding structural overload and significantly improving safety.

[0072] 2. By setting up an anti-jamming mechanism, a miniature hydraulic cylinder is used to drive a hammer to strike the dam surface, actively eliminating jamming between adjacent dam surfaces, improving operational reliability, and reducing dam surface damage and downtime. Attached Figure Description

[0073] Figure 1 This is a schematic diagram of a hydraulic dam intelligent control method based on finite element analysis proposed in this invention;

[0074] Figure 2 This is a flowchart illustrating the anti-jamming mechanism of an intelligent control method for hydraulic dams based on finite element analysis proposed in this invention.

[0075] Figure 3 This is a three-dimensional view of the dam surface structure of a hydraulic dam intelligent control method based on finite element analysis proposed in this invention.

[0076] Figure 4 This is a three-dimensional view of the guide channel structure of the intelligent control method for hydraulic dams based on finite element analysis proposed in this invention.

[0077] Figure 5 This is a three-dimensional view of a micro hydraulic cylinder structure for a hydraulic dam intelligent control method based on finite element analysis proposed in this invention.

[0078] Figure 6 This is a three-dimensional view of the support rod structure of the intelligent control method for hydraulic dams based on finite element analysis proposed in this invention.

[0079] Figure 7 This is a three-dimensional view of the hammer structure of a hydraulic dam intelligent control method based on finite element analysis proposed in this invention.

[0080] In the diagram: 1. Dam surface; 2. Miniature hydraulic cylinder; 21. Support rod; 22. Connecting plate; 23. Hammer; 24. Limiting plate; 3. Elastic sealing strip; 4. Guide channel. Detailed Implementation

[0081] 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 only some embodiments of the present invention, and not all embodiments.

[0082] Reference Figure 1 A smart control method for hydraulic dams based on finite element analysis includes the following steps:

[0083] S1. Real-time acquisition of key data parameters: The system collects four types of key data parameters in real time according to the preset frequency: hydraulic load parameters, structural response parameters, hydraulic system parameters, and environmental and operational parameters. The collected key data parameters are then uploaded to the backend system.

[0084] S2. Finite Element Analysis: The background system calls the finite element analysis engine to perform parametric finite element analysis, specifically including:

[0085] A1. Establish a parametric finite element model: Based on the design parameters of the hydraulic dam, a finite element model including geometric dimensions, material properties and boundary conditions is established in advance. The finite element model uses the dam surface inclination angle 1 as the driving parameter. The mesh attitude and element orientation are dynamically and adaptively adjusted in real time by rotating the mesh coordinates, and the element stiffness matrix is ​​updated synchronously.

[0086] A2. Real-time equivalent application of load: The collected hydraulic load parameters are converted into the total water pressure of the superposition of hydrostatic pressure and dynamic water pressure. The total water pressure is mapped into the nodal force of 1 element on the dam surface in a uniform distribution manner. At the same time, the self-weight of the dam body is converted into nodal force as a volume force and applied to the finite element model simultaneously.

[0087] A3. Solution and Result Extraction: The overall equilibrium equation is solved using an implicit statics solver. Post-processing calculations are performed based on the displacement results, combined with strain-displacement and stress-strain relationships. The maximum equivalent stress and corresponding location, maximum normal deformation, support reaction force of each hydraulic cylinder hinge point, and contact pressure of adjacent dam surfaces 1 are extracted.

[0088] A4. Threshold Comparison and Grading: The equivalent stress, normal deformation, hydraulic cylinder hinge point support reaction force, and dam surface contact pressure obtained from the finite element solution are compared with their respective preset safety thresholds to classify safety levels and calculate the comprehensive safety factor.

[0089] S3. Comprehensive decision-making: Combining the finite element classification results, comprehensive safety factor, and river water level and flow scheduling target, comprehensively determine whether to execute the hydraulic dam lifting action, and determine the target inclination angle, target flow rate, and flow velocity of each dam face.

[0090] S4. Hydraulic system coordinated and precise control: Each dam face 1 corresponds to an independent solenoid valve. The opening degree of the corresponding solenoid valve is independently adjusted based on the deviation between the actual inclination angle and the target inclination angle of each dam face 1 as the control input. At the same time, according to the total flow demand of all dam faces 1 to be operated and the comprehensive safety margin of finite element feedback, the output power of the variable frequency motor is dynamically adjusted and matched with the output power of the hydraulic pump to achieve synchronous and precise movement of multiple dam faces 1.

[0091] To provide comprehensive and real-time input data for finite element analysis and ensure calculation accuracy, hydraulic load parameters in S1 include upstream water level, downstream water level, water depth in front of the dam, water depth behind the dam, and flow velocity through the dam.

[0092] The structural response parameters include the inclination angle of each dam face 1, the surface strain of each dam face 1 along the height direction, the bending moment at the root of each dam face 1, and the gap displacement between adjacent dam faces 1.

[0093] The hydraulic system parameters include the rod chamber pressure and rodless chamber pressure of each hydraulic cylinder, the piston rod extension displacement of each hydraulic cylinder, the hydraulic pump outlet pressure, the hydraulic pump output flow rate, the valve core position feedback of each solenoid valve, the hydraulic oil temperature, and the variable frequency motor current and output power.

[0094] Environmental and operational parameters include river water temperature, floating debris density index, and dam vibration acceleration.

[0095] To ensure consistency between the finite element model and the actual posture of the dam body and to improve the accuracy of calculations, in A1, the geometric dimensions include the length, width, thickness, and hinge point positions of each dam face 1.

[0096] Material properties include elastic modulus, Poisson's ratio, density, and yield strength.

[0097] Boundary conditions include constraints on the hinged supports at the bottom of the dam body, lateral water-stopping displacement constraints, and contact between adjacent dam faces 1.

[0098] To achieve accurate conversion between water load and dam self-weight, in section A2, the collected upstream and downstream water level data are converted into hydrostatic pressure loads distributed along dam face 1, using the following formula: ,in, For hydrostatic pressure, For fluid density, It is the acceleration due to gravity. The depth is the vertical downward direction from the fluid surface.

[0099] The dynamic water pressure load is calculated based on the flow velocity over the dam using the following formula: ,in, For dynamic water pressure, This is the empirical dynamic pressure coefficient. The velocity of the flow over the dam.

[0100] The total water pressure is obtained by vector superposition of the hydrostatic pressure and the hydrodynamic pressure, using the following formula: ,in, The total water pressure is mapped as a uniformly distributed surface load to the nodal force of element 1 on the dam surface. At the same time, the dam body's self-weight is converted as a volume force and applied to the nodal force simultaneously to the finite element model.

[0101] In order to accurately obtain key structural response indicators, in A3, the overall equilibrium equation is composed of the overall stiffness matrix of the hydraulic dam, the nodal displacement vector, and the equivalent nodal force vector. The overall stiffness matrix is ​​assembled from the stiffness matrices of each element and is updated in real time with the inclination angle of the dam surface 1. The strain and stress of the elements are obtained through displacement post-processing, and then the maximum equivalent stress, the maximum support reaction force of the hydraulic cylinder hinge point, the maximum normal deformation of the dam surface 1, and the maximum contact pressure of the adjacent dam surface 1 are determined.

[0102] Overall equilibrium equation: ,in, The overall stiffness matrix of the hydraulic dam is assembled from the stiffness matrices of individual elements and is updated as the dam face inclination angle changes. Let be the displacement vector for all nodes. This is the equivalent nodal force vector.

[0103] Element stiffness matrix: ,in, The element stiffness matrix, The strain-displacement matrix is... The elastic constitutive matrix is ​​determined by the elastic modulus and Poisson's ratio. for transpose, For the volume domain of the element.

[0104] Strain-displacement relationship: ,in, Let S be the strain vector at a point within the element. This represents the displacement vector of all nodes in this element.

[0105] Stress-strain relationship: ,in, This is the stress vector at a point within the element.

[0106] Equivalent stress: ,in, For equivalent stress, , , These are the first principal stress, the second principal stress, and the third principal stress, respectively. The maximum value is selected. As .

[0107] Support reaction calculation: ,in, The maximum value is taken as the support reaction vector at the constraint node. As .

[0108] Normal deformation: ,in, For the transformation of the Dharma form, and Let be the displacement vector in three-dimensional space. , , for Components in the x-axis, y-axis, and z-axis directions. , , for The components along the x, y, and z axes are selected based on their maximum values. As .

[0109] Contact pressure between adjacent dam faces: , ,in, For normal contact force, For contact stiffness, For penetration depth, To contact pressure, For the contact area, take the maximum value. As .

[0110] To achieve multi-dimensional, multi-threshold structural safety classification assessment, the safety level classification method in A4 is as follows:

[0111] The maximum equivalent stress on each dam face 1 of the hydraulic dam is compared with the material yield strength:

[0112] when It was then a green safe zone, in which, This represents the yield strength of the material.

[0113] when It is currently a yellow alert zone.

[0114] when It is currently an orange danger zone.

[0115] when It was then a red emergency zone.

[0116] Compare the maximum support reaction force at the hinge point of each hydraulic cylinder with the maximum allowable support reaction force designed for that hydraulic cylinder:

[0117] when At that time, it was determined to be a green safe zone, in which, This is the maximum permissible support reaction force of the hydraulic cylinder.

[0118] when At that time, it was determined to be a yellow alert zone.

[0119] when At that time, it was determined to be an orange danger zone.

[0120] The maximum contact pressure between adjacent dam faces 1 extracted by finite element analysis is compared with the preset allowable contact pressure:

[0121] when At that time, it was determined to be a green safe zone, in which, This is the preset contact pressure.

[0122] when At that time, it was determined to be a yellow alert zone.

[0123] when At that time, it was determined to be an orange danger zone.

[0124] Compare the maximum normal deformation and allowable deflection of each dam face 1:

[0125] when At that time, it was determined to be a green safe zone, in which, This represents the allowable deflection of the dam surface.

[0126] when At that time, it was determined to be a yellow alert zone.

[0127] when At that time, it was determined to be an orange danger zone.

[0128] when At that time, it was designated as a red emergency zone.

[0129] Calculate the overall safety factor: ,in, This is for the safety factor.

[0130] The comprehensive decision-making process in S3 includes:

[0131] When any dam face 1 is in the orange danger zone or the red emergency zone, a dam lowering command is forcibly issued and all dam raising commands are locked.

[0132] When any dam face 1 is in a yellow warning zone and the current water level is higher than the flood limit level, raising the dam is prohibited.

[0133] Raising or lowering the dam is permitted when all dam faces 1 are in the green safety zone and the dam posture needs to be adjusted according to the water level-flow scheduling rules.

[0134] The target inclination angle is determined as follows: the theoretical target inclination angle of each dam face 1 is calculated back based on the target flow rate, and then the theoretical target inclination angle is substituted back into the finite element model for pre-simulation. If the pre-simulation stress exceeds the limit, the target inclination angle is reduced or step-by-step adjustment is adopted.

[0135] To achieve precise coordinated and energy-saving control of multiple dam faces 1, in S4, the deviation between the actual inclination angle and the target inclination angle of each dam face 1 is used as the input of the PID controller, and the output PWM signal controls the opening degree of the solenoid valve core. The formula is as follows: ,in, For the first The error value of each dam surface, For the first The target inclination angle value of the dam face. For the first The actual measured inclination angle of each dam face.

[0136] The PID parameters are dynamically adjusted based on the support reaction force of each hydraulic cylinder on each dam face 1 obtained from finite element analysis. The larger the load, the larger the proportional coefficient. At the same time, the tilt angle difference between adjacent dam faces 1 is monitored in real time. When the tilt angle difference exceeds the set threshold, the opening priority of each solenoid valve is automatically adjusted to maintain synchronization.

[0137] The following calculations are used to adjust the output power of a variable frequency motor:

[0138] Total demand flow: ,in, The total flow required for the dam face 1 that is currently in operation. The effective working area of ​​the hydraulic cylinder. The target speed.

[0139] Power required for hydraulic pump: ,in, The hydraulic power required by the hydraulic pump. This refers to the fluid pressure output by the hydraulic pump.

[0140] Motor drive frequency: ,in, This refers to the motor drive frequency that the inverter needs to output. This refers to the operating frequency of the motor at its rated power. This refers to the rated power of the motor. For overall efficiency.

[0141] The power required by the hydraulic pump is calculated based on the total demand flow rate of the dam surface 1 and the output pressure of the hydraulic pump. The drive frequency of the variable frequency motor is determined by combining the rated parameters of the motor and the overall efficiency of the system. When the comprehensive safety factor is lower than the preset threshold, the upper limit of the hydraulic pump power is reduced proportionally to constrain the dam body's movement speed and lifting amplitude.

[0142] By using parametric finite element analysis to analyze the dam's stress, deformation, support reaction force, and contact pressure in real time, a multi-threshold safety assessment based on actual stress, deformation, support reaction force, and contact pressure can be achieved, effectively avoiding structural overload and significantly improving safety.

[0143] like Figures 2-7As shown, the present invention proposes an intelligent control method for hydraulic dams based on finite element analysis, which also includes an anti-jamming mechanism. The anti-jamming mechanism includes miniature hydraulic cylinders 2 and support rods 21 arranged in a rectangular array near the gap between two adjacent dam surfaces 1. One end of the piston rod of the miniature hydraulic cylinder 2 is fixedly sleeved with a connecting plate 22. The inner wall of the connecting plate 22 is slidably engaged with the surface of the support rod 21. A striking hammer 23 is fixedly connected to the side of the connecting plate 22 closest to the dam surface 1. When the contact pressure of adjacent dam surfaces 1 exceeds the limit, it is determined that a floating object or stone is stuck in the gap between adjacent dam surfaces 1. The extension and retraction of the piston rod of the miniature hydraulic cylinder 2 drives the connecting plate 22 connected to it to move along the surface of the support rod 21. At the same time, the movement of the connecting plate 22 drives the striking hammer 23 to apply a brief directional impact force to the dam surface 1, shaking off the foreign object.

[0144] In order to move the hammer 23 in a directional manner, a limiting plate 24 is fixedly sleeved on the handle of the hammer 23. The inner wall of the limiting plate 24 is slidably engaged with the surface of the support rod 21 to support the hammer 23 and facilitate its directional movement.

[0145] By setting up an anti-jamming mechanism, a miniature hydraulic cylinder 2 drives a hammer 23 to strike the dam surface 1, actively eliminating jamming between adjacent dam surfaces 1, improving operational reliability, and reducing damage to dam surface 1 and downtime.

[0146] To reduce foreign object jamming, an elastic sealing strip 3 is installed between the gaps of two adjacent dam faces 1, and a flow guide groove 4 is provided. The elastic sealing strip 3 has the dual functions of flexible sealing and initial foreign object prevention. Non-large hard foreign objects are blocked outside the gap. When the water flow carries small foreign objects into the gap area, the flow guide groove 4 changes the local water flow streamline and uses water force to guide the foreign objects to the outside of the gap instead of pushing them into the depth of the gap, effectively reducing foreign object embedding.

[0147] Working principle: During use, the system continuously collects hydraulic load parameters, structural response parameters, hydraulic system parameters, and environmental and operational parameters through deployed sensors. The collected data is uploaded to the backend system, which calls the parametric finite element model to convert the real-time water load into nodal forces. An implicit statics solver is used to calculate the structural response of the dam body under the current working conditions. The maximum equivalent stress, maximum normal deformation, hydraulic cylinder hinge point support reaction force, and contact pressure of adjacent dam faces 1 are extracted. The maximum equivalent stress, maximum normal deformation, hydraulic cylinder hinge point support reaction force, and contact pressure of adjacent dam faces 1 are compared with their respective preset safety thresholds to classify the safety level and calculate the comprehensive safety factor.

[0148] According to the safety classification results and the river water level and flow scheduling rules, when any dam face 1 is in the orange danger zone or the red emergency zone, a dam lowering command is forcibly issued and all dam raising commands are blocked. When any dam face 1 is in the yellow warning zone and the current water level is higher than the flood limit water level, dam raising is prohibited. When all dam faces 1 are in the green safety zone and the dam body attitude needs to be adjusted according to the water level and flow scheduling rules, dam raising and lowering are allowed.

[0149] The deviation between the actual inclination angle and the target inclination angle of each dam face 1 is used as the PID input. The output PWM duty cycle is used to adjust the valve core opening of the solenoid valve. The PID parameters are dynamically adjusted according to the reaction force of each cylinder support obtained by finite element method. At the same time, the inclination angle difference between adjacent dam faces 1 is monitored. When the difference exceeds the tolerance, the priority of each valve is automatically adjusted to maintain synchronization. The required hydraulic power is calculated according to the total flow demand of all dam faces 1. The frequency converter adjusts the motor frequency according to the formula so that the output power of the hydraulic pump is accurately matched with the load. When the comprehensive safety factor is lower than the threshold, the maximum hydraulic power is limited proportionally to actively slow down the action speed.

[0150] When the contact pressure on the adjacent dam surface 1 exceeds the limit, it is determined that a foreign object is stuck. The extension and retraction of the piston rod of the micro hydraulic cylinder 2 drives the connecting plate 22 connected to it to move along the surface of the support rod 21. At the same time, the movement of the connecting plate 22 drives the hammer 23 to apply a brief directional impact force to the dam surface 1, shaking off the foreign object. The contact pressure is monitored again in real time. When the contact pressure is normal, the hammering stops. When the contact pressure is still too high, the micro hydraulic cylinder 2 is started again to drive the hammer 23 to strike. If the contact pressure is still too high according to the real-time monitoring, an audible and visual alarm is issued to prompt the staff to intervene.

[0151] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A smart control method for hydraulic dams based on finite element analysis, characterized in that, Includes the following steps: S1. Real-time acquisition of key data parameters: The system collects four types of key data parameters in real time, namely hydraulic load parameters, structural response parameters, hydraulic system parameters, and environmental and operational parameters, according to the preset acquisition frequency, and uploads the collected key data parameters to the back-end system. S2. Finite Element Analysis: The background system calls the finite element analysis engine to perform parametric finite element analysis, specifically including: A1. Establish a parametric finite element model: Based on the design parameters of the hydraulic dam, a finite element model containing geometric dimensions, material properties and boundary conditions is established in advance. The finite element model uses the inclination angle of the dam surface (1) as the driving parameter. The grid attitude and unit orientation are dynamically and adaptively adjusted by real-time deflection of the grid coordinates, and the unit stiffness matrix is ​​updated synchronously. A2. Real-time equivalent application of load: The collected hydraulic load parameters are converted into the total water pressure superimposed by hydrostatic pressure and dynamic water pressure. The total water pressure is mapped into the nodal force of the dam surface (1) unit in a uniform distribution manner. At the same time, the self-weight of the dam body is converted into nodal force as a volume force and applied to the finite element model simultaneously. A3. Solving and Result Extraction: The implicit statics solver is used to solve the overall equilibrium equation. Based on the displacement results, combined with the strain-displacement relationship and stress-strain relationship, post-processing calculations are performed to extract the maximum equivalent stress and corresponding position of each dam surface (1), the maximum normal deformation, the support reaction force of each hydraulic cylinder hinge point, and the contact pressure of adjacent dam surfaces (1). A4. Threshold comparison and classification: The equivalent stress, normal deformation, hydraulic cylinder hinge point support reaction force and dam surface (1) contact pressure obtained by finite element solution are compared with their respective preset safety thresholds to classify safety levels and calculate comprehensive safety factor. S3. Comprehensive decision-making: Based on the finite element classification results, comprehensive safety factor, and river water level and flow scheduling target, comprehensively determine whether to execute the hydraulic dam lifting action, and determine the target inclination angle and target flow rate and flow velocity of each dam face (1); S4. Hydraulic system coordinated and precise control: Each dam face (1) has an independent solenoid valve. The opening degree of the corresponding solenoid valve is independently adjusted by taking the deviation between the actual tilt angle and the target tilt angle of each dam face (1) as the control input. At the same time, according to the total flow demand of all dam faces (1) to be operated and the comprehensive safety margin of finite element feedback, the output power of the variable frequency motor is dynamically adjusted and matched with the output power of the hydraulic pump to achieve synchronous and precise movement of the attitude of multiple dam faces (1).

2. The intelligent control method for hydraulic dams based on finite element analysis according to claim 1, characterized in that: In S1, the hydraulic load parameters include upstream water level, downstream water level, water depth in front of the dam, water depth behind the dam, and flow velocity across the dam. The structural response parameters include the inclination angle of each dam face (1), the surface strain of each dam face (1) along the height direction, the bending moment at the root of each dam face (1), and the gap displacement between adjacent dam faces (1). The hydraulic system parameters include the rod chamber pressure and rodless chamber pressure of each hydraulic cylinder, the piston rod extension displacement of each hydraulic cylinder, the hydraulic pump outlet pressure, the hydraulic pump output flow, the valve core position feedback of each solenoid valve, the hydraulic oil temperature, and the variable frequency motor current and output power. The environmental and operational parameters include river water temperature, floating debris density index, and dam vibration acceleration.

3. The intelligent control method for hydraulic dams based on finite element analysis according to claim 1, characterized in that: In A1, the geometric dimensions include the length, width, thickness, and hinge point position of each dam face (1); The material properties include elastic modulus, Poisson's ratio, density, and yield strength; The boundary conditions include the hinge support constraint at the bottom of the dam body, the lateral water-stopping displacement constraint, and the contact between adjacent dam faces (1).

4. The intelligent control method for hydraulic dams based on finite element analysis according to claim 1, characterized in that: In A2, the collected upstream and downstream water level data are converted into hydrostatic pressure loads distributed along the dam face (1), and the formula is: ,in, For hydrostatic pressure, For fluid density, It is the acceleration due to gravity. The depth perpendicularly downwards from the fluid surface; The dynamic water pressure load is calculated based on the flow velocity over the dam using the following formula: ,in, For dynamic water pressure, This is the empirical dynamic pressure coefficient. The velocity of the flow over the dam; The total water pressure is obtained by vector superposition of the hydrostatic pressure and the hydrodynamic pressure, using the following formula: ,in, The total water pressure is mapped to the nodal force of the dam surface (1) element in a uniformly distributed surface load manner. At the same time, the dam body weight is converted into nodal force as a volume force and applied to the finite element model.

5. The intelligent control method for hydraulic dams based on finite element analysis according to claim 1, characterized in that: In the A3, the overall equilibrium equation is composed of the overall stiffness matrix of the hydraulic dam, the nodal displacement vector and the equivalent nodal force vector. The overall stiffness matrix is ​​assembled from the stiffness matrices of each unit and is updated in real time with the inclination angle of the dam surface (1). The unit strain and stress are obtained through displacement post-processing, and then the maximum equivalent stress, the maximum support reaction force of the hydraulic cylinder hinge point, the maximum normal deformation of the dam surface (1) and the maximum contact pressure of adjacent dam surfaces (1) are determined. Overall equilibrium equation: ,in, The overall stiffness matrix of the hydraulic dam is assembled from the stiffness matrices of individual elements and is updated as the dam face inclination angle changes. Let be the displacement vector for all nodes. This is the equivalent nodal force vector; Element stiffness matrix: ,in, The element stiffness matrix, The strain-displacement matrix is... The elastic constitutive matrix is ​​determined by the elastic modulus and Poisson's ratio. for transpose, For the volume domain of the element; Strain-displacement relationship: ,in, Let S be the strain vector at a point within the element. This represents the displacement vector of all nodes in this element; Stress-strain relationship: ,in, This represents the stress vector at a point within the element. Equivalent stress: ,in, For equivalent stress, , , These are the first principal stress, the second principal stress, and the third principal stress, respectively. The maximum value is selected. As ; Support reaction calculation: ,in, The maximum value is taken as the support reaction vector at the constraint node. As ; Normal deformation: ,in, For the transformation of the Dharma form, and Let be the displacement vector in three-dimensional space. , , for Components in the x-axis, y-axis, and z-axis directions. , , for The components along the x, y, and z axes are selected based on their maximum values. As ; Contact pressure between adjacent dam faces (1): , ,in, For normal contact force, For contact stiffness, For penetration depth, To contact pressure, For the contact area, take the maximum value. As .

6. The intelligent control method for hydraulic dams based on finite element analysis according to claim 3, characterized in that: The security level classification method in A4 is as follows: The maximum equivalent stress on each face (1) of the hydraulic dam is compared with the material yield strength: when It was then a green safe zone, in which, The yield strength of the material; when It was a yellow alert zone at the time; when The area is currently in the orange danger zone. when It was then a red emergency zone; Compare the maximum support reaction force at the hinge point of each hydraulic cylinder with the maximum allowable support reaction force designed for that hydraulic cylinder: when At that time, it was determined to be a green safe zone, in which, This is the maximum permissible support reaction force of the hydraulic cylinder; when At that time, it was determined to be a yellow alert zone; when At that time, it was determined to be an orange danger zone; The maximum contact pressure between adjacent dam faces (1) extracted by finite element analysis is compared with the preset allowable contact pressure: when At that time, it was determined to be a green safe zone, in which, The preset contact pressure; when At that time, it was determined to be a yellow alert zone; when At that time, it was determined to be an orange danger zone; The maximum normal deformation of each dam face (1) is compared with the allowable deflection: when At that time, it was determined to be a green safe zone, in which, This represents the allowable deflection of the dam surface; when At that time, it was determined to be a yellow alert zone; when At that time, it was determined to be an orange danger zone; when At that time, it was determined to be a red emergency zone; Calculate the overall safety factor: ,in, This is for the safety factor.

7. The intelligent control method for hydraulic dams based on finite element analysis according to claim 6, characterized in that: The comprehensive decision-making process in S3 includes: When any dam face (1) is in the orange danger zone or the red emergency zone, a dam lowering command is forcibly issued and all dam raising commands are locked. When any dam face (1) is in a yellow warning zone and the current water level is higher than the flood limit level, raising the dam is prohibited; When all dam faces (1) are in the green safety zone and the dam posture needs to be adjusted according to the water level-flow scheduling rules, raising and lowering the dam is permitted; The method for determining the target inclination angle is as follows: calculate the theoretical target inclination angle of each dam face (1) based on the target flow rate, and then substitute the theoretical target inclination angle back into the finite element model for pre-simulation. If the pre-simulation stress exceeds the limit, reduce the target inclination angle or adopt step-by-step adjustment.

8. The intelligent control method for hydraulic dams based on finite element analysis according to claim 6, characterized in that: In S4, the deviation between the actual inclination angle and the target inclination angle of each dam face (1) is used as the input of the PID controller, and the output PWM signal controls the opening degree of the solenoid valve core. The formula is as follows: ,in, For the first The error value of each dam surface, For the first The target inclination angle value of the dam face. For the first The actual measured inclination angle of each dam face; The PID parameters are dynamically adjusted based on the support reaction force of the hydraulic cylinder of each dam face (1) obtained from the finite element analysis. The larger the load, the larger the proportional coefficient. At the same time, the inclination angle difference between adjacent dam faces (1) is monitored in real time. When the inclination angle difference exceeds the set threshold, the opening priority of each solenoid valve is automatically adjusted to maintain synchronization. The following calculations are used to adjust the output power of a variable frequency motor: Total demand flow: ,in, This represents the total flow required for the dam to be in operation. The effective working area of ​​the hydraulic cylinder. For target speed; Power required for hydraulic pump: ,in, The hydraulic power required by the hydraulic pump. This refers to the fluid pressure output by the hydraulic pump; Motor drive frequency: ,in, This refers to the motor drive frequency that the inverter needs to output. This refers to the operating frequency of the motor at its rated power. This refers to the rated power of the motor. For overall efficiency; The power required by the hydraulic pump is calculated based on the total demand flow of the dam surface (1) and the output pressure of the hydraulic pump. The driving frequency of the variable frequency motor is determined by combining the rated parameters of the motor and the overall efficiency of the system. When the comprehensive safety factor is lower than the preset threshold, the upper limit of the hydraulic pump power is reduced proportionally to constrain the dam body's movement speed and lifting amplitude.

9. The intelligent control method for hydraulic dams based on finite element analysis according to claim 1, characterized in that: It also includes an anti-jamming mechanism, which includes miniature hydraulic cylinders (2) and support rods (21) arranged in a rectangular array near the gap between two adjacent dam surfaces (1). One end of the piston rod of the miniature hydraulic cylinder (2) is fixedly sleeved with a connecting plate (22). The inner wall of the connecting plate (22) is slidably engaged with the surface of the support rod (21). A striking hammer (23) is fixedly connected to the side surface of the connecting plate (22) near the dam surface (1). A limiting plate (24) is fixedly sleeved on the handle of the striking hammer (23). The inner wall of the limiting plate (24) is slidably engaged with the surface of the support rod (21).

10. The intelligent control method for hydraulic dams based on finite element analysis according to claim 9, characterized in that: An elastic sealing strip (3) is installed between the gaps of two adjacent dam surfaces (1), and a flow guide groove (4) is provided.

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