Hydraulic synchronous sliding control system and method for nuclear power steel roof truss installation

Abstract

This invention relates to the field of slip control technology, specifically disclosing a hydraulic synchronous slip control system and method for installing steel roof trusses in nuclear power plants. The method includes: synchronously acquiring the oil pressure changes and stroke increments at each slip support point to identify hidden off-center load nodes; extracting the load sharing ratio to analyze additional deformation internal forces and delineating the allowable adjustment range; constructing a trial unloading gradient within the allowable range, evaluating the virtual pressure relief response, and generating the optimal unloading action sequence; driving the hidden off-center load node to independently perform micro-pressure reduction to assess the resistance elimination state; analyzing the displacement hysteresis deviation based on the state and converting it into a resynchronization compensation amount, redistributing the dynamic rate to restore global synchronization. This invention achieves the identification and adjustment of hidden off-center loads in slip control, which is beneficial for ensuring the safety of the slip structure.

Description

Technical Field

[0001] This invention relates to the field of sliding control technology, specifically to a hydraulic synchronous sliding control system and method for installing steel roof trusses in nuclear power plants. Background Technology

[0002] In the installation of steel roof trusses on the conventional island of nuclear power plants, the hydraulic synchronous cumulative sliding process has been gradually introduced into the field. By assembling in a fixed area and then hydraulically pushing and sliding the entire structure to the design position, the reliance on ultra-large tonnage lifting equipment is effectively reduced.

[0003] However, during the multi-point hydraulic synchronous sliding of nuclear power plant steel roof trusses, uneven stress on the support points is easily caused by factors such as differences in the friction coefficients of each sliding track, mechanical assembly clearances, and local track elevation errors. Existing hydraulic synchronous sliding control systems typically use stroke synchronization error as the main control basis. When a local sliding support point becomes stuck due to a sudden increase in friction, the overall rigidity of the steel roof truss means that the support point may still be dragged forward by the surrounding supports in terms of macroscopic displacement, thus exhibiting a state of basically synchronized stroke but local obstruction.

[0004] This state of synchronized but locally obstructed movement is known as "hidden eccentric loading." Under these conditions, the existing system cannot detect changes in internal stress and continues to output hydraulic thrust, leading to a rapid accumulation of localized eccentric shear force and additional deformation forces at the stuck joint. Once the stress exceeds the yield strength of the main steel structure material, or is suddenly released during slippage, it will cause irreversible torsional deformation, joint tearing, or even overall instability and overturning of the steel roof truss, posing a significant safety hazard to nuclear power plant construction.

[0005] Therefore, the present invention provides a hydraulic synchronous sliding control system and method for installing steel roof trusses in nuclear power plants. Summary of the Invention

[0006] The purpose of this invention is to provide a hydraulic synchronous sliding control system and method for the installation of steel roof trusses in nuclear power plants, so as to solve the problems that it is difficult to identify the implicit off-center load state of stroke synchronization but local obstruction in the existing hydraulic synchronous sliding control process, and it is difficult to complete the pressure relief adjustment and resynchronization recovery under the premise of ensuring structural safety.

[0007] The objective of this invention can be achieved through the following technical solutions: A hydraulic synchronous sliding control method for installing steel roof trusses in nuclear power plants includes the following steps: The oil pressure change and stroke increment of each sliding pivot are collected synchronously to generate the resistance response characteristics of the corresponding pivot. By comparing the deviation of the resistance response characteristics from the normal operating benchmark, the hidden off-load nodes that are synchronous in stroke but locally obstructed are identified. Extract the current load sharing ratio of the hidden off-center load nodes and adjacent supports, and analyze the additional deformation internal forces of the steel roof truss; based on the additional deformation internal forces, define the allowable adjustment range of the hidden off-center load nodes without compromising structural stability. For implicit off-center load nodes, multiple sets of trial unloading gradients are constructed within the allowable adjustment range, and the corresponding virtual pressure relief responses are analyzed. The matching degree between the virtual pressure relief responses and the preset force balance benchmark is evaluated, the optimal pressure relief timing is selected, and an unloading action sequence is generated based on the optimal pressure relief timing. According to the unloading action sequence, the implicit off-center load node is driven to break away from the global synchronization constraint and perform micro-motion voltage reduction independently, and the actual unloading amplitude fed back by the implicit off-center load node is obtained; the current resistance elimination state of the implicit off-center load node is evaluated based on the actual unloading amplitude.

[0008] Furthermore, the method for identifying the hidden biased load node is as follows: Extract the continuous resistance response characteristics of each sliding support point of the steel roof truss during steady-state operation in the barrier-free test section, and construct the normal operation benchmark by calculating the statistical mean. Calculate the deviation of the current resistance response characteristics from the normal operating baseline; Read real-time stroke data and global stroke reference issued by the hydraulic main control system, and calculate the stroke synchronization error of real-time stroke data relative to global stroke reference; A tolerance warning identification logic is constructed. The characteristic deviation degree and the travel synchronization error are input into the tolerance warning identification logic, and the sliding support point with force accumulation is identified and marked as the hidden off-center load node.

[0009] Furthermore, the process of generating the aforementioned resistance response characteristics is as follows: According to the hardware polling cycle, real-time hydraulic pressure data and real-time stroke data of each sliding pivot are read synchronously and stored in the data cache window; Boundary extreme value analysis is performed on the data cache window to obtain the oil pressure change and stroke increment at the slip pivot; a judgment logic for physical stagnation is established, and the stroke increment is input into the judgment logic to determine the physical stagnation state; The calculation dimension is determined based on the spatial scale characteristics of the stroke increment, and the oil pressure change rate is calculated in the corresponding spatial or time domain. Then, the dimensional transformation and alignment are performed based on the global reference rate to achieve dynamic construction of resistance response characteristics.

[0010] Furthermore, the process of establishing the allowable adjustment range is as follows: Read the hydraulic cylinder parameters corresponding to the hidden off-center load node and calculate the actual bearing capacity of the hidden off-center load node to obtain the load sharing ratio; Extract the rigid sharing benchmark to calculate the local eccentric load shear force, map the local eccentric load shear force to the pre-set spatial structural mechanics model, and solve to generate the spatial additional deformation internal force; extract the geometric parameters of the target section, and convert the spatial additional deformation internal force and the local eccentric load shear force into the three-dimensional spatial stress tensor of the corresponding node; Substitute the three-dimensional spatial stress tensor into the fourth strength theory equation to calculate the equivalent stress value; extract the material yield limit and combine it with the equivalent stress value to determine the residual stress capacity, and then convert the residual stress capacity into the equivalent fluid pressure. Extract the current oil pressure value of the hidden off-center load node, and derive the upper limit by combining the current oil pressure value with the equivalent fluid pressure; derive the lower limit by combining the local steel roof truss self-weight, and establish the allowable adjustment range based on the upper and lower limit derivation results.

[0011] Furthermore, the unloading action sequence is generated in the following way: Multiple sets of trial unloading gradients are generated by discrete sampling within the allowable adjustment range; the cylinder space vector is extracted and the trial unloading gradient is converted into a local pressure relief vector; Extract the pre-set load transfer coefficient of the structure, map the local pressure relief vector to the load transfer coefficient, calculate and derive the change in structural reaction force, and generate a virtual pressure relief response; Extract the force balance benchmark, input the virtual decompression response into the preset evaluation function to solve the evaluation cost value; compare the evaluation cost value to extract the minimum value to determine the optimal decompression timing sequence, and substitute the optimal decompression timing sequence into the pulse width modulation algorithm to generate the unloading action sequence executed at the bottom layer.

[0012] Furthermore, the method for solving the evaluation value is as follows: Read the current bearing capacity and rated bearing capacity of adjacent sliding support points, calculate the difference between the rated bearing capacity and the current bearing capacity, and use it as the force balance benchmark; Retrieve the preset evaluation function, which sets the pressure relief resistance weight and the structural safety weight. For each virtual pressure relief response, the quotient of the target pressure reduction amplitude and the maximum pressure reduction amplitude in the allowable adjustment range is calculated to obtain the pressure reduction depth coefficient. The pressure reduction depth coefficient is then multiplied by the pressure relief resistance weight to obtain the efficiency cost component. Extract the structural reaction force change contained in the virtual decompression response, and take the equivalent scalar value of the structural reaction force change in the force direction of the adjacent sliding support; calculate the quotient of the equivalent scalar value and the force equilibrium benchmark, and multiply the quotient by the structural safety weight to obtain the risk cost component; By adding the efficiency cost component and the risk cost component, the evaluation value of the corresponding virtual decompression response is calculated.

[0013] Furthermore, the process for assessing the state of resistance elimination is as follows: Injecting a flexible decoupling command switches the global synchronization loop between the hidden off-center load node and the hydraulic main control system to impedance control mode, and loads the unloading action sequence to drive the hidden off-center load node to perform micro-motion pressure reduction. The final stable oil pressure during the micro-pressure reduction process is collected, and the actual unloading amplitude is calculated by combining it with the initial original oil pressure. The pressure release rate waveform is read and feature extraction is performed to calculate the number of polarity reversals, the final pressure release deviation, and the time span for the derivative to return to zero. Feature splicing is then performed to generate a multi-dimensional waveform feature vector. Calculate the spatial characteristic distance between the waveform feature vector and each preset standard evolution centroid, select the optimal matching target based on the minimum value, and output the current resistance elimination state of the implicit off-center load node.

[0014] Furthermore, it also includes: analyzing the displacement lag deviation of the implicit off-center load node due to the implementation of independent pressure reduction based on the resistance elimination state analysis, and converting the displacement lag deviation into a resynchronization compensation amount; based on the resynchronization compensation amount, redistributing the dynamic rate to all sliding support points and restoring the global synchronization state.

[0015] Furthermore, the method for converting it into the resynchronization compensation amount is as follows: Read the real-time travel coordinates of the hidden off-center load node and the normal operation support point, use the vector difference algorithm to calculate the spatial deviation of the real-time travel coordinates, and derive the displacement hysteresis deviation. Using the resistance elimination state as an index, the state compensation coefficient is extracted from the preset mapping relationship by looking up a table; and based on the displacement hysteresis deviation and the state compensation coefficient, the resynchronization compensation amount is calculated and generated using a closed-loop feedback adjustment algorithm.

[0016] A hydraulic synchronous sliding control system for installing steel roof trusses in nuclear power plants includes the following modules: Off-center load identification module: used to synchronously collect oil pressure changes and stroke increments to generate resistance response characteristics; by comparing the deviation of the resistance response characteristics with the normal operating benchmark, hidden off-center load nodes are identified. Interval construction module: used to extract the current load sharing ratio of implicit off-center load nodes and adjacent supports, analyze the additional deformation internal forces of steel roof trusses, and delineate the allowable adjustment range of implicit off-center load nodes. Pressure relief adjustment module: used to construct multiple sets of trial unloading gradients for implicit off-center load nodes within the allowable adjustment range, analyze and generate corresponding virtual pressure relief responses; evaluate the matching degree between the virtual pressure relief responses and the preset force balance benchmark, select the optimal pressure relief timing sequence, and generate unloading action sequence; Status assessment module: used to drive the implicit off-center load node to break away from the global synchronization constraint and perform micro-motion voltage reduction independently according to the unloading action sequence, and obtain the actual unloading amplitude fed back by the implicit off-center load node; and assess the current resistance elimination status of the implicit off-center load node based on the actual unloading amplitude. State recovery module: It is used to analyze the displacement hysteresis deviation of the hidden off-center load node based on the resistance elimination state analysis, and convert the displacement hysteresis deviation into the resynchronization compensation amount; based on the resynchronization compensation amount, it redistributes the dynamic rate of all sliding support points and restores the global synchronization state.

[0017] The beneficial effects of this invention are as follows: 1. By dynamically extracting characteristic indicators representing the work done per unit stroke resistance and comparing them with global benchmarks in multiple dimensions, it is beneficial to identify potential jamming nodes, control the hidden stress accumulation caused by sudden changes in local friction, and improve the sensitivity of identifying abnormal stress states in the early stages of slippage. Based on the sharing ratio of actual load and theoretical proportion, the additional deformation internal force at mid-span of the structure is derived, and the residual stress capacity of the structure is calculated. The mechanical force boundary is inversely converted into a continuous fluid pressure range that the control system can directly identify. This helps prevent the risk of structural overload or physical collapse caused by blindly reducing pressure and unloading, ensuring that the adjustment process remains within the elastic safety stress range.

[0018] 2. By constructing multiple sets of trial gradients through discrete sampling within the safe control range, and combining the cylinder installation space vector with the structural load transfer coefficient for forward simulation, and by dynamically adjusting the weight equation based on the stress approximation ratio for cost evaluation, the execution sequence is finally compiled and executed using a pulse width modulation algorithm. This helps to select an actuation sequence that balances pressure relief efficiency and the safety of adjacent structures, mitigating the secondary stress impact of local pressure reduction on large-span space frames. Spatial Euclidean distance optimization matching is achieved by combining the instantaneous pressure derivative with the standard evolved centroid library. This technique of local decoupling control combined with multi-dimensional waveform feature recognition enables independent control of fault fulcrums, facilitating the determination of whether resistance has been truly eliminated and controlling the risk of secondary jamming caused by blind secondary propulsion.

[0019] 3. By aligning spatial coordinates and quantifying displacement hysteresis using an analytical displacement model, voltage gain is calculated based on state mapping relationships and feedforward adjustment algorithms, enabling dynamic adjustment of the target catch-up rate and the coordinated deceleration ratio. This facilitates coordination between the lagging nodes and the normal support points, maintains a smooth transition during the elimination of local cumulative displacement deviations, mitigates the step-like rigid impact when reclosing the global synchronization loop, and optimizes the attitude coordination of subsequent sliding in large-span steel structures. Attached Figure Description

[0020] The invention will now be further described with reference to the accompanying drawings.

[0021] Figure 1 This is a flowchart of a hydraulic synchronous sliding control method for installing steel roof trusses in nuclear power plants according to the present invention; Figure 2 This is a flowchart illustrating the process of identifying hidden off-center load nodes according to the present invention; Figure 3This is a functional block diagram of a hydraulic synchronous sliding control system for installing steel roof trusses in nuclear power plants, as described in this invention. Detailed Implementation

[0022] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0023] Example 1:

[0024] like Figure 1 and Figure 2 As shown, a hydraulic synchronous sliding control method for installing steel roof trusses in nuclear power plants includes the following steps: S1. Synchronously collect the oil pressure change and stroke increment of each sliding support point to generate the resistance response characteristics of the corresponding support point; by comparing the deviation of the resistance response characteristics from the normal operating benchmark, identify the hidden off-load nodes where the stroke is synchronized but locally obstructed. The process of simultaneously collecting the oil pressure changes and stroke increments at each sliding pivot point and generating the corresponding resistance response characteristics of the pivot point is as follows: S101. Read the real-time hydraulic pressure data and real-time stroke data of each sliding pivot point synchronously according to the hardware polling cycle and store them in the data cache window; Specifically, the process of storing data in the data cache window is as follows: According to the hardware polling cycle of the hydraulic control system, the real-time oil pressure data of each sliding pivot is continuously read, and the real-time stroke data of the displacement sensors arranged at each sliding pivot is read simultaneously. Establish a data cache window with a fixed time step, and store the continuously read real-time oil pressure data and real-time stroke data into the data cache window in sequence; S102. Perform boundary extreme value analysis on the data cache window to obtain the oil pressure change and stroke increment of the sliding pivot. Specifically, the process of performing boundary extreme value analysis is as follows: Extract the latest and oldest oil pressure values ​​from the data cache window, calculate the difference between the latest and oldest oil pressure values, and obtain the oil pressure change. Extract the latest and oldest trip values ​​from the data cache window, calculate the difference between the latest and oldest trip values, and obtain the trip increment. S103. Establish the judgment logic for physical stagnation state, input the stroke increment into the judgment logic to determine the physical stagnation state; determine the calculation dimension based on the spatial scale characteristics of the stroke increment, and calculate the oil pressure change rate in the corresponding spatial domain or time domain to realize the dynamic construction of resistance response characteristics. Specifically, the method for establishing the judgment logic and dynamically constructing the resistance response characteristics is as follows: If the stroke increment is zero, it indicates that the corresponding sliding pivot is in a state of physical stagnation, and the resistance response characteristic is assigned a value of zero. A threshold for permissible micro-displacement is set. If the stroke increment is greater than the threshold, the ratio of oil pressure change to stroke increment is calculated. If the stroke increment is greater than zero and less than or equal to the threshold, a preset time sampling step is extracted, and the ratio of oil pressure change to time sampling step is calculated as the intensity change rate in the time dimension. Simultaneously, the global reference rate issued by the hydraulic main control system is extracted, and the intensity change rate in the time dimension is divided by the global reference rate to convert it into an equivalent spatial resistance change rate. This eliminates numerical extremes caused by micro-displacement in space and maintains dimensional consistency during global comparison, dynamically outputting resistance response characteristics. The lower limit of the micro-displacement threshold is controlled by the hardware measurement resolution of the displacement sensor, and the upper limit is calibrated based on the empirical value of the static friction creep displacement of the sliding guide rail; the time sampling step is synchronized with the underlying instruction scanning cycle of the hydraulic main control system PLC. The process of identifying hidden off-center load nodes that are synchronized in stroke but locally obstructed by comparing the deviation of resistance response characteristics from normal operating benchmarks is as follows: Extract the continuous resistance response characteristics of each sliding support point of the steel roof truss during steady-state operation in the barrier-free test section, and construct the normal operation benchmark by calculating the statistical mean. Calculate the difference between the current resistance response characteristic and the normal operating baseline, solve for the ratio of the obtained difference to the normal operating baseline, convert the ratio into a percentage form, and obtain the characteristic deviation. Read the global stroke reference issued by the hydraulic main control system, calculate the absolute value of the real-time stroke data minus the global stroke reference, and obtain the stroke synchronization error; Construct a tolerance early warning identification logic, input the characteristic deviation degree and the stroke synchronization error into the tolerance early warning identification logic, and identify the slip support point with force accumulation as the hidden off-center load node; The method for constructing the tolerance warning identification logic is as follows: determine whether the feature deviation is greater than the off-load warning limit, and determine whether the travel synchronization error is less than the physical tolerance limit; If the characteristic deviation is greater than the off-center load warning limit and the stroke synchronization error is less than the physical tolerance limit, it indicates that the corresponding sliding pivot is synchronized in macroscopic displacement, but there is significant resistance and accumulation in microscopic force. The sliding pivot with force accumulation is marked as a hidden off-center load node. If the characteristic deviation is not greater than the off-center load warning limit, or the stroke synchronization error is not less than the physical tolerance limit, it indicates that the corresponding sliding pivot is in a healthy stress state or has exposed obvious physical lag. A normal execution command to maintain the original driving state is issued to determine that the corresponding sliding pivot is a non-hidden off-center load node. It should be noted that the process of determining the physical tolerance limit is as follows: read the values ​​recorded on the sliding equipment drawings to determine the mechanical assembly clearance; read the single-span misalignment limit marked in the engineering design specifications, add the single-span misalignment limit to the mechanical assembly clearance, and superimpose them to obtain the limit displacement deviation; determine the limit displacement deviation as the physical tolerance limit. For example, the process of determining the off-center load warning limit is as follows: extract the extreme values ​​of resistance fluctuations stored in historical test records; calculate the difference between the extreme values ​​of resistance fluctuations and the normal operating baseline, solve for the quotient of the difference data and the normal operating baseline and convert it into a percentage format to obtain the historical fluctuation ratio; extract the safety redundancy coefficient preset by the main control system program; add the safety redundancy coefficient to the historical fluctuation ratio and accumulate to obtain the off-center load warning limit. The safety redundancy coefficient is the inherent disturbance margin of the system hardware, calculated by superimposing the root mean square noise of the displacement sensor and the oil pressure sensor with the extreme envelope of the steady-state fluid pulsation of the hydraulic pipeline. It is not a fixed constant set subjectively.

[0025] S2. Extract the current load sharing ratio of the hidden off-center load nodes and adjacent supports, and analyze the additional deformation internal force of the steel roof truss; based on the additional deformation internal force, define the allowable adjustment range of the hidden off-center load nodes without compromising structural stability. The process of extracting the current load-sharing ratio of the implicit off-center load nodes and adjacent supports, and deducing the additional deformation internal forces of the steel roof truss, is as follows: S201. Calculate the actual bearing capacity of the hidden off-center load node based on the hydraulic cylinder parameters corresponding to the hidden off-center load node, and obtain the load sharing ratio. Specifically, the load sharing ratio is obtained as follows: Read the real-time oil pressure values ​​of the hidden off-center load node and its adjacent support points, and multiply them by the effective working area of ​​the corresponding hydraulic cylinder to calculate the actual bearing capacity of the hidden off-center load node and its adjacent support points. Read the real-time oil pressure values ​​of each sliding pivot point in the hydraulic control system, and calculate the total global load by combining the effective working area of ​​each hydraulic cylinder; S202. Extract the rigid sharing benchmark to calculate the local eccentric load shear force, input the local eccentric load shear force into the pre-set steel roof truss spatial structural mechanical model for equilibrium calculation, and derive the spatial additional deformation internal force. Specifically, the process of generating additional spatial deformation internal forces is as follows: Read the pre-set rigidity bearing benchmark in the steel roof truss design drawings; It should be noted that the value of the rigid load-sharing benchmark is given in advance according to the stiffness distribution principle in the design drawings, representing the theoretical load-bearing share of the node under ideal design conditions. The dimensions of the rigid load-sharing benchmark are consistent with the load-sharing ratio calculated in real time. The difference between the load sharing ratio and the rigid sharing benchmark is calculated, and this difference is multiplied by the total global load to calculate the local eccentric shear force released from the implicit eccentric load node to the outside. Retrieve the preset spatial stiffness matrix and structural topology model of the steel roof truss, and extract the node spatial coordinates and element connection relationships contained in the structural topology model as the basic parameters of the spatial structural mechanics model of the steel roof truss; transform the local eccentric shear force released from the implicit eccentric load node to the outside into the non-equilibrium node load, and construct the spatial load vector accordingly. By combining the spatial stiffness matrix and the spatial load vector, a system based on... The system's static equilibrium equations; in Here is the spatial stiffness matrix. For spatial load vectors, Let be the spatial displacement vector to be determined; The static equilibrium equations of the system are solved using numerical methods to obtain the spatial displacement vectors of each node in the local region where the hidden eccentric load node is located. The element stiffness matrix of each main structural member in the local region where the hidden eccentric load node is located is extracted. The spatial displacement vectors are substituted into the corresponding element stiffness matrix to calculate the element end forces of each main structural member. The element end forces are decomposed to extract the three-dimensional nodal moment components (including bidirectional bending moment and torque) and spatial force components (including axial internal force and transverse shear force) of each main structural member. These components are then combined to generate the complete spatial additional deformation internal force in the local region where the hidden eccentric load node is located. The process of determining the allowable adjustment range of the implicit off-center load node without compromising structural stability, based on the additional deformation internal force, is as follows: S211. Extract the geometric parameters of the target section and convert the complete spatial additional deformation internal force into the three-dimensional spatial stress tensor of the corresponding node. Specifically, the process of converting the stress into the three-dimensional stress tensor of the corresponding node is as follows: Read the principal axis moment of inertia, polar moment of inertia, static moment of section, and effective cross-sectional area preset in the steel roof truss drawings as the geometric parameters of the target section; Based on the effective cross-sectional area and principal axis moment of inertia, the axial internal force and bidirectional bending moment contained in the complete spatial additional deformation internal force are transformed into the triaxial normal stress components of the corresponding nodes. Based on the effective cross-sectional area, principal axis moment of inertia and static moment of the cross section, the transverse shear stress caused by the transverse shear force in the complete spatial additional deformation internal force is calculated, and the torsional shear stress caused by the torque is calculated by combining the polar moment of inertia. The transverse shear stress and torsional shear stress are superimposed to generate the three-dimensional spatial shear stress components of the corresponding nodes. The three-dimensional normal stress components are used as the main diagonal elements, and the three-dimensional spatial shear stress components are used as off-diagonal elements according to the shear stress reciprocity theorem to assemble a second-order symmetric matrix, thereby constructing the three-dimensional spatial stress tensor of the corresponding node. S212. Substitute the three-dimensional spatial stress tensor into the fourth strength theory equation to calculate the equivalent stress value; Specifically, the process of calculating the equivalent stress value is as follows: The triaxial normal stress component and the three-dimensional shear stress component in the three-dimensional spatial stress tensor are extracted and substituted into the spatial stress state yield equation of the fourth strength theory to calculate the equivalent stress value of the comprehensive stress state of the hidden off-center load node. It should be noted that the fourth strength theory equation is a well-known theory in mechanics of materials. Under the three-dimensional stress state characterized by the stress tensor, the equivalent stress calculation based on this theory involves the combined derivation of the square terms of the difference of normal stress in each direction and the square terms of the shear stress in each dimension (i.e., solving for the second invariant of the deviatoric stress of the tensor). In the implementation of this scheme, the extracted triaxial normal stress components and the three-dimensional shear stress components can be input into the three-dimensional standard calculation formula corresponding to the theory to output the equivalent stress value. This calculation process can be automatically completed by being built into the data processing module of the control system. S213. Extract the yield strength of the material and determine the residual stress capacity in combination with the equivalent stress value, and convert the residual stress capacity into equivalent fluid pressure. Specifically, the process of converting it into equivalent fluid pressure is as follows: Preferably, the process of deriving the residual stress capacity is as follows: read the nominal tensile strength value of the main steel roof truss material from the factory and set it as the nominal tensile strength value; and set a safety reduction factor according to the mandatory provisions of the engineering specifications. Among them, the safety reduction factor is directly extracted from the resistance partial factor and importance reduction factor that are mandatory for large-span temporary space bearing structures in the steel structure design standard. This factor is used to reduce the nominal value of the tensile strength at the factory, providing an absolute material elastic safety margin for the micro-pressure reduction process. The material yield strength is obtained by combining the nominal tensile strength value with a safety reduction factor to perform a safety derating calculation. The residual stress capacity of the steel roof truss under the current stress state is obtained by subtracting the equivalent stress value from the yield strength of the material. Read the effective working area of ​​the hydraulic cylinder corresponding to the hidden off-center load node, and calculate the ultimate load that the structure can withstand by combining the remaining stress capacity with the bearing cross-sectional area of ​​the steel structure at the hidden off-center load node. Based on the effective working area of ​​the hydraulic cylinder, the ultimate load is converted in reverse into an equivalent fluid pressure that the hydraulic system can identify; S214. Extract the current oil pressure value of the hidden off-center load node, combine the current oil pressure value with the equivalent fluid pressure to derive the upper limit; combine the local steel roof truss self-weight to derive the lower limit, and establish the allowable adjustment range based on the upper and lower limit derivation results. Specifically, the method for deriving the upper and lower limits is as follows: Extract the current oil pressure value of the hidden off-center load node and determine the current oil pressure value as the upper limit of the pressure reduction for this micro-motion; Read the pressure of the hydraulic main control system to maintain the local steel roof truss from falling due to its own weight, and determine the pressure of the fall prevention line as the lower limit value of the pressure. When the current oil pressure value is higher than the fall protection bottom line pressure, and the remaining bearing margin corresponding to the equivalent fluid pressure meets the safety requirements of the micro-pressure reduction process, the lower limit pressure value is used as the lower boundary of the closed interval, and the current oil pressure value is used as the upper boundary of the closed interval to generate the allowable adjustment range of the hidden off-center load node. It should be noted that the value of the fall arrestor line pressure is based on: extracting the equivalent self-weight load rigidly distributed within the local structural range where the hidden off-center load node is located, superimposing the maximum static friction resistance between the sliding guide shoe and the track corresponding to the node, and calculating the minimum balance pressure value necessary to maintain the zero displacement of the node based on the effective working area of ​​the hydraulic cylinder.

[0026] Example 2:

[0027] Please see Figure 1 As shown, a hydraulic synchronous sliding control method for installing steel roof trusses in nuclear power plants includes the following steps: S3. For implicit off-center load nodes, construct multiple sets of trial unloading gradients within the allowable adjustment range, analyze and generate corresponding virtual pressure relief responses; evaluate the matching degree between the virtual pressure relief responses and the preset force balance benchmark, select the optimal pressure relief timing, and generate an unloading action sequence based on the optimal pressure relief timing. Specifically, for implicit off-load nodes, multiple sets of trial unloading gradients are constructed within the allowable adjustment range, and the process of generating the corresponding virtual decompression response is analyzed as follows: S301. Within the allowable adjustment range, discrete sampling generates multiple sets of trial unloading gradients; extracts the cylinder space vector and converts the trial unloading gradients into local pressure relief vectors; Specifically, the process of generating multiple sets of trial unloading gradients is as follows: Read the upper and lower pressure limits of the allowable adjustment range; The numerical space between the upper and lower pressure limits is discretely sampled according to a fixed pressure step size to generate multiple target oil pressures after pressure relief. Calculate the difference between the current oil pressure value and the oil pressure after each target pressure relief to obtain the corresponding target pressure reduction range; Extract multiple hydraulic action steps from the bottom layer of the hydraulic control system, cross-pair the target pressure reduction amplitude with the hydraulic action steps, and combine them to construct multiple sets of trial unloading gradients; Specifically, the method for converting it into a local pressure relief vector is as follows: Read the effective working area of ​​the hydraulic cylinder corresponding to the hidden off-center load node, multiply the target pressure reduction amplitude by the effective working area of ​​the hydraulic cylinder, and calculate the scalar unloading force at the hidden off-center load node. The main control system reads the cylinder spatial direction vector pre-calibrated based on the steel roof truss coordinate system. The cylinder spatial direction vector is used to characterize the axial thrust direction of the physical installation of the hydraulic cylinder. The scalar unloading force is assigned a direction value along the spatial direction vector of the cylinder to generate a local pressure relief vector with a clear spatial action direction; S302. Extract the pre-set load transfer coefficient of the structure, map the local pressure relief vector to the load transfer coefficient, calculate and derive the change in structural reaction force, and generate a virtual pressure relief response. Specifically, the process of generating a virtual decompression response is as follows: Extract the load transfer coefficient pre-set according to the steel roof truss design drawings; It should be noted that the load transfer factor reflects the proportion of the mechanical reaction force gain generated by the unit force change at the implicit off-center load node on the surrounding adjacent sliding support points. By multiplying the local pressure relief vector by the load transfer coefficient, the change in structural reaction force passively borne by adjacent sliding supports due to the unloading of the implicit off-center load node is derived. The target depressurization magnitude is data-bound with the derived structural reaction force change to generate a virtual depressurization response corresponding to each set of trial unloading gradients; The process of evaluating the matching degree between the virtual decompression response and the preset force balance benchmark, selecting the optimal decompression timing sequence, and generating an unloading action sequence based on the optimal decompression timing sequence is as follows: S311. Extract the force balance benchmark, input the virtual pressure relief response into the preset evaluation function to solve the evaluation value. The function of the evaluation function is to quantify the balance between pressure relief efficiency and structural safety risk. Specifically, the process of determining the evaluation value is as follows: Read the current bearing capacity and rated bearing capacity of adjacent sliding support points, calculate the difference between the rated bearing capacity and the current bearing capacity, determine the obtained difference as the remaining bearing margin of adjacent sliding support points, and use the remaining bearing margin as the force balance benchmark; Retrieve the preset evaluation function, which sets the pressure relief resistance weight and the structural safety weight. For each virtual pressure relief response, the quotient of the target pressure reduction amplitude and the maximum pressure reduction amplitude in the allowable adjustment range is calculated to obtain the pressure reduction depth coefficient. The pressure reduction depth coefficient is then multiplied by the pressure relief resistance weight to obtain the efficiency cost component. Extract the structural reaction force change contained in the virtual decompression response, and take the equivalent scalar value of the structural reaction force change in the force direction of the adjacent sliding support; calculate the quotient of the equivalent scalar value and the force equilibrium benchmark, and multiply the quotient by the structural safety weight to obtain the risk cost component; The efficiency cost component and the risk cost component are added together to calculate the evaluation value of the corresponding virtual decompression response. It should be noted that the methods for setting the pressure relief resistance weight and the structural safety weight are as follows: By calling the current equivalent stress value pre-calculated by the main control system and the preset yield limit of the main steel roof truss material, the stress approximation ratio between the current equivalent stress and the material yield limit is solved; the stress approximation ratio is directly mapped to the unit interval as the core safety variable to generate a dynamic structural safety weight; the constant 1 is extracted as the preset absolute full load limit, and the structural safety weight is subtracted from the absolute full load limit to calculate and generate a dynamic pressure relief resistance weight. It should be noted that the core idea of ​​the evaluation function is to quantify the two costs of efficiency and risk into comparable values ​​and perform a weighted summation. In the specific implementation of this technical solution, the equation is constructed as a weighted sum of the efficiency cost component and the risk cost component. The absolute full load limit is preset to a constant 1. Its mechanical and mathematical significance is that the stress approximation ratio is essentially the quotient of the current equivalent stress and the material yield limit. It belongs to a dimensionless normalization parameter. The value of 1 represents the theoretical full load state where the stress state strictly reaches the yield critical point. S312. Compare and evaluate the cost value to extract the minimum value to determine the optimal decompression timing. Substitute the optimal decompression timing into the pulse width modulation algorithm to generate the unloading action sequence executed at the bottom layer. Specifically, the process of generating the unloading action sequence is as follows: Read the evaluation values ​​corresponding to all virtual decompression responses, sort them by value, and extract the evaluation value with the smallest value; The trial unloading gradient corresponding to the smallest evaluation cost value is determined as the optimal decompression timing. Extract the target pressure reduction magnitude and hydraulic action step size included in the optimal pressure release timing sequence; Read the rated flow coefficient of the hydraulic proportional pressure reducing valve at the hidden off-center load node, and combine it with the bulk elastic modulus of the hydraulic oil to convert the target pressure reduction amplitude into the valve opening time required to achieve pressure relief. Substitute the valve opening time into the pulse width modulation algorithm to calculate the target duty cycle of the valve opening time relative to the hydraulic action step. Based on the chronological order, the hydraulic action step length and target duty cycle are compiled into a voltage pulse control word that the proportional pressure reducing valve can recognize, thereby generating an unloading action sequence.

[0028] S4. According to the unloading action sequence, drive the implicit off-center load node to break away from the global synchronization constraint and perform micro-motion voltage reduction independently, and obtain the actual unloading amplitude fed back by the implicit off-center load node; evaluate the current resistance elimination state of the implicit off-center load node based on the actual unloading amplitude. The process of driving the implicit biased load node to break free from the global synchronization constraint and perform micro-voltage reduction independently, according to the unloading action sequence, and obtaining the actual unloading amplitude fed back by the implicit biased load node is as follows: S401, Inject flexible decoupling command to switch the global synchronization loop between the hidden off-center load node and the hydraulic main control system to impedance control mode. By introducing preset virtual damping parameters, the energy mutation rate at the moment of node release is limited, and the unloading action sequence is loaded to drive the hidden off-center load node to perform micro-motion pressure reduction. It should be noted that the initial calibration value of the virtual damping parameter is obtained in advance by using the critical damping configuration criterion based on the equivalent mass of the steel structure in the local area where the implicit off-center load node is located and the bulk elastic modulus of the fluid in the hydraulic control circuit. By setting this parameter, the energy release process during the node's micro-motion pressure reduction is forced into an overdamped or critically damped attenuation state. Specifically, the execution process is as follows: Following the unloading action sequence, the implicit biased load node is driven to break free from the global synchronization constraint and perform micro-motion voltage reduction independently. The process of obtaining the actual unloading amplitude fed back by the implicit biased load node is as follows: Read the control channel number where the hidden off-center load node is located, inject a flexible decoupling command for the control channel number, switch the global synchronization loop between the hidden off-center load node and the hydraulic main control system to impedance control mode, and limit the energy mutation rate at the moment of node release by introducing a preset virtual damping parameter, so that the hidden off-center load node enters the independent pressure regulation mode under controlled energy consumption state. The unloading action sequence is converted into the underlying drive level, and the underlying drive level is used to drive the proportional pressure reduction valve at the implicit off-load node to perform micro-pressure reduction. S402. Collect the final stable oil pressure during the micro-pressure reduction process, and calculate the actual unloading amplitude by combining it with the initial original oil pressure. Specifically, the method for calculating the actual unloading extent is as follows: Extract the initial oil pressure of the hidden off-center load node before performing micro-pressure reduction; After the unloading action sequence is completed, the transient oil pressure sequence of the hidden off-center load node is continuously read. The transient oil pressure sequence is input into a preset first-order low-pass filter algorithm, which uses the inertial delay characteristic to filter out the high-frequency pressure noise generated by fluid turbulence and outputs the final stable oil pressure after convergence. The pressure difference between the initial oil pressure and the final steady oil pressure is calculated, and the pressure difference obtained is determined as the actual unloading amplitude. The process of assessing the current resistance elimination state of the implicit off-center load node based on the actual unloading amplitude is as follows: S411. Read the decompression rate waveform, perform feature extraction, calculate the number of polarity reversals, the final state decompression deviation, and the time span when the derivative returns to zero, and perform feature splicing to generate a multi-dimensional waveform feature vector. Specifically, the process of splicing and generating multi-dimensional waveform feature vectors is as follows: extract the transient oil pressure sequence continuously recorded by the latent off-center load node throughout the entire micro-pressure reduction cycle; Read the system's preset time sampling step size, combine the transient oil pressure sequence with the time sampling step size to perform differential calculation, and extract the instantaneous pressure derivative at each sampling moment; By sequentially combining the continuous instantaneous pressure derivatives along the time axis, a pressure release rate waveform representing the evolution of pressure decay is generated. Extract the target pressure reduction range contained in the optimal pressure release timing obtained from step S3, and determine the target pressure reduction range as the expected pressure release endpoint. For example, the process of performing feature extraction on the decompression rate waveform and generating a waveform feature vector is as follows: Read all instantaneous pressure derivatives contained in the pressure release rate waveform, count the cumulative number of times the instantaneous pressure derivatives changed sign, and obtain the number of polarity reversals; Establish a tail data window at the end of the micro-pressure reduction cycle, calculate the average absolute difference between the transient oil pressure sequence within the tail data window and the expected pressure release endpoint, and obtain the final pressure release deviation. Extract the absolute time point at which the instantaneous pressure derivative first decays to zero within the pressure relief rate waveform, calculate the time span between the absolute time point and the start time of the micro-pressure reduction, and obtain the time span for the derivative to return to zero. The number of polarity reversals, the final state decompression deviation, and the time span when the derivative returns to zero are arranged in a matrix according to a preset dimensional order, and combined to construct the waveform feature vector of the current unloading cycle; S412. Calculate the spatial characteristic distance between the waveform feature vector and each preset standard evolution centroid, select the optimal matching target based on the minimum value optimization, and output the current resistance elimination status of the hidden off-center load node. Specifically, the process of determining the current resistance elimination state of the hidden off-center load node is as follows: Retrieve the system's preset mechanical evolution feature library and extract multiple standard evolution centroids that match the current steel roof truss type and sliding equipment parameters from the mechanical evolution feature library; The multiple standard evolution centroids correspond to the states of resistance elimination, residual resistance, and consolidation and jamming, respectively. Each standard evolution centroid is obtained by statistically solidifying the waveform feature vectors in historical sliding obstacle removal samples or on-site debugging samples. For each standard evolution centroid, the Euclidean distance between the waveform feature vector and each standard evolution centroid in the multidimensional feature space is calculated, and multiple corresponding spatial feature distances are generated. Read all spatial feature distances of the corresponding centroids representing the compliant, residual, and consolidated centroids; Minimize all spatial feature distances, extract the spatial feature distance with the smallest value, and determine the standard evolution centroid corresponding to the spatial feature distance with the smallest value as the optimal matching target. Extract the mechanical and physical state bound to the standard evolution centroid corresponding to the optimal matching target, and output it as the current resistance elimination state of the hidden off-center load node.

[0029] S5. Based on the resistance elimination state analysis, the displacement lag deviation of the hidden off-center load node caused by the independent pressure reduction is analyzed, and the displacement lag deviation is converted into the resynchronization compensation amount; based on the resynchronization compensation amount, the dynamic rate is redistributed to all sliding support points and the global synchronization state is restored. The process of analyzing the displacement hysteresis deviation of the implicit off-center load node due to the independent pressure reduction based on the resistance elimination state analysis, and converting the displacement hysteresis deviation into the resynchronization compensation amount, is as follows: S501. Read the real-time travel coordinates of the hidden off-center load node and the normal operation support point, use the vector difference algorithm to calculate the spatial deviation of the real-time travel coordinates, and derive the displacement hysteresis deviation. Specifically, the method for deriving the displacement hysteresis error is as follows: Extract the transient travel coordinates of the hidden off-center load node at the instant the fretting voltage reduction is completed; Synchronously read the reference stroke coordinates of the hydraulic system at the normal operating fulcrum; Align the transient travel coordinates with the reference travel coordinates in space, calculate the spatial deviation of the transient travel coordinates relative to the reference travel coordinates using a vector difference algorithm, and determine the spatial deviation as the current displacement hysteresis deviation of the implicit off-center load node. S502. Using the resistance elimination state as an index, extract the state compensation coefficient from the preset mapping relationship by looking up a table; and based on the displacement hysteresis deviation and the state compensation coefficient, use a closed-loop feedback adjustment algorithm to calculate and generate the resynchronization compensation amount. Specifically, the process of converting the amount into resynchronization compensation is as follows: The system's preset state mapping matrix is ​​retrieved, which contains discrete gain mapping relationships corresponding to different resistance elimination states. The state compensation coefficient corresponding to the current resistance elimination state is extracted by performing key-value addressing matching on the input state mapping matrix. The preset closed-loop feedback adjustment algorithm is invoked, which includes proportional-integral operation logic for converting displacement deviation into underlying drive power. The displacement hysteresis deviation and the state compensation coefficient are combined as the input variable set, and the input variable set is substituted into the closed-loop feedback control algorithm for proportional-integral control. The closed-loop feedback control algorithm outputs the speed compensation amount based on the displacement hysteresis deviation and its changing trend, and determines the speed compensation amount as the resynchronization compensation amount. It should be noted that the state mapping matrix and the discrete gain mapping relationship configured within it are expert experience data tables generated by statistical fitting after multiple closed-loop slip disturbance simulations and physical tests on a scaled-down mechanical model of the nuclear power plant steel roof truss, collecting the optimal closed-loop control gain parameters that enable the system to recover synchronization fastest under different resistance elimination states. The process of redistributing dynamic rates to all sliding pivots and restoring global synchronization based on the resynchronization compensation is as follows: S511, retrieve the global reference rate and load the resynchronization compensation amount into the preset dynamic allocation unit, and derive the target catch-up rate and cooperative deceleration ratio based on the principle of flow conservation; Specifically, the process of deriving the target catch-up rate and the coordinated deceleration ratio is as follows: Retrieve the global reference rate within the hydraulic main control system to maintain the steady-state movement of the steel roof truss; The global reference rate is added to the resynchronization compensation amount to calculate the target catch-up rate of the implicit off-load node; Extract the effective working area of ​​the hydraulic cylinder corresponding to the hidden off-center load node, multiply the resynchronization compensation amount by the effective working area, and calculate the additional flow demand generated by the acceleration of the hidden off-center load node. Based on the principle of total flow conservation of the slip system, the additional flow demand is deducted as a total amount. According to the effective working area ratio of the hydraulic cylinders corresponding to each normal working point, the total amount of deduction is distributed and deducted to the base flow of each normal working point. The actual flow after deduction is converted to generate the coordinated speed reduction ratio of each normal working point. S512: Generate low-level control commands based on the target chasing rate and the coordinated deceleration ratio, drive the global sliding pivot to change the execution rate and reclose the global synchronization loop, and restore the global synchronization state. Specifically, the process of restoring the global synchronization state is as follows: based on the target catch-up rate, an acceleration pulse sequence is generated that acts on the proportional speed control valve of the hidden off-center load node; Based on the coordinated speed reduction ratio, a pressure reduction delay sequence is generated that acts on the proportional speed control valve at the normal operating fulcrum. The acceleration pulse sequence and the voltage reduction delay sequence are combined and packaged, and compiled into low-level control instructions corresponding to each sliding pivot point; The underlying control commands are sent to the hardware execution layer of each sliding pivot point to drive each proportional speed control valve to perform seamless rate switching actions. After the rate change operation is completed, the flexible decoupling command applied to the implicit off-center load node is released and the impedance control mode is exited. The communication bus and monitoring link of the hydraulic main control system are reconnected, the global synchronization loop of all sliding pivots is closed, and the final output system enters a healthy global synchronization state.

[0030] Example 3:

[0031] Please see Figure 3 As shown, a hydraulic synchronous sliding control system for installing steel roof trusses in nuclear power plants includes the following modules: Off-center load identification module: used to synchronously collect the oil pressure change and stroke increment of each sliding support point, and generate the resistance response characteristics of the corresponding support point; by comparing the deviation of the resistance response characteristics with the normal operating benchmark, the hidden off-center load nodes with synchronous stroke but local obstruction are identified. Interval Construction Module: Used to extract the current load sharing ratio of implicit off-center load nodes and adjacent supports, analyze the additional deformation internal forces of steel roof trusses; and delineate the allowable adjustment range of implicit off-center load nodes without compromising structural stability based on the additional deformation internal forces. The pressure relief adjustment module is used to construct multiple sets of trial unloading gradients for implicit off-center load nodes within the allowable adjustment range, analyze and generate corresponding virtual pressure relief responses, evaluate the matching degree between the virtual pressure relief responses and the preset force balance benchmark, select the optimal pressure relief timing sequence, and generate an unloading action sequence based on the optimal pressure relief timing sequence. Status assessment module: used to drive the implicit off-center load node to break away from the global synchronization constraint and perform micro-motion voltage reduction independently according to the unloading action sequence, and obtain the actual unloading amplitude fed back by the implicit off-center load node; and assess the current resistance elimination status of the implicit off-center load node based on the actual unloading amplitude. State recovery module: It is used to analyze the displacement hysteresis deviation of the implicit off-center load node due to the independent pressure reduction based on the resistance elimination state analysis, and convert the displacement hysteresis deviation into the resynchronization compensation amount; based on the resynchronization compensation amount, it redistributes the dynamic rate of all sliding support points and restores the global synchronization state.

[0032] The foregoing has provided a detailed description of one embodiment of the present invention, but this description is merely a preferred embodiment and should not be construed as limiting the scope of the invention. All equivalent variations and modifications made within the scope of the present invention should still fall within the scope of the present invention.

Claims

1. A hydraulic synchronous sliding control method for installing steel roof trusses in nuclear power plants, characterized in that, Includes the following steps: The oil pressure change and stroke increment of each sliding pivot are collected synchronously to generate the resistance response characteristics of the corresponding pivot. By comparing the deviation of the resistance response characteristics from the normal operating benchmark, the hidden off-load nodes that are synchronous in stroke but locally obstructed are identified. Extract the current load sharing ratio of the hidden off-center load nodes and adjacent supports, and analyze the additional deformation internal forces of the steel roof truss. Based on the additional deformation internal force, the allowable adjustment range of the implicit off-center load node is defined without compromising structural stability. For implicit off-center load nodes, multiple sets of trial unloading gradients are constructed within the allowable adjustment range, and the corresponding virtual pressure relief responses are analyzed. The matching degree between the virtual pressure relief responses and the preset force balance benchmark is evaluated, the optimal pressure relief timing is selected, and an unloading action sequence is generated based on the optimal pressure relief timing. According to the unloading action sequence, the implicit off-center load node is driven to break away from the global synchronization constraint and perform micro-motion voltage reduction independently, and the actual unloading amplitude fed back by the implicit off-center load node is obtained; the current resistance elimination state of the implicit off-center load node is evaluated based on the actual unloading amplitude.

2. The hydraulic synchronous sliding control method for nuclear power steel roof truss installation according to claim 1, characterized in that: The method for identifying the hidden off-center load node is as follows: Extract the continuous resistance response characteristics of each sliding support point of the steel roof truss during steady-state operation in the barrier-free test section, and construct the normal operation benchmark by calculating the statistical mean. Calculate the deviation of the current resistance response characteristics from the normal operating baseline; Read real-time stroke data and global stroke reference issued by the hydraulic main control system, and calculate the stroke synchronization error of real-time stroke data relative to global stroke reference; A tolerance warning identification logic is constructed. The characteristic deviation degree and the travel synchronization error are input into the tolerance warning identification logic, and the sliding support point with force accumulation is identified and marked as the hidden off-center load node.

3. The hydraulic synchronous sliding control method for nuclear power steel roof truss installation according to claim 2, characterized in that: The process of generating the aforementioned resistance response characteristics is as follows: According to the hardware polling cycle, real-time hydraulic pressure data and real-time stroke data of each sliding pivot are read synchronously and stored in the data cache window; Boundary extreme value analysis is performed on the data cache window to obtain the oil pressure change and stroke increment at the slip pivot; a judgment logic for physical stagnation is established, and the stroke increment is input into the judgment logic to determine the physical stagnation state; The calculation dimension is determined based on the spatial scale characteristics of the stroke increment, and the oil pressure change rate is calculated in the corresponding spatial or time domain. Then, the dimensional transformation and alignment are performed based on the global reference rate to achieve dynamic construction of resistance response characteristics.

4. The hydraulic synchronized sliding control method for nuclear power steel roof truss installation of claim 1, wherein: The process of establishing the allowable adjustment range is as follows: Read the hydraulic cylinder parameters corresponding to the hidden off-center load node and calculate the actual bearing capacity of the hidden off-center load node to obtain the load sharing ratio; Extract the rigid sharing benchmark to calculate the local eccentric load shear force, map the local eccentric load shear force to the pre-set spatial structural mechanics model, and solve to generate the spatial additional deformation internal force; extract the geometric parameters of the target section, and convert the spatial additional deformation internal force and the local eccentric load shear force into the three-dimensional spatial stress tensor of the corresponding node; Substitute the three-dimensional spatial stress tensor into the fourth strength theory equation to calculate the equivalent stress value; extract the material yield limit and combine it with the equivalent stress value to determine the residual stress capacity, and then convert the residual stress capacity into the equivalent fluid pressure. Extract the current oil pressure value of the hidden off-center load node, and derive the upper limit by combining the current oil pressure value with the equivalent fluid pressure; derive the lower limit by combining the local steel roof truss self-weight, and establish the allowable adjustment range based on the upper and lower limit derivation results.

5. The hydraulic synchronized sliding control method for nuclear power steel roof truss installation of claim 1, wherein: The method for generating the unloading action sequence is as follows: Multiple sets of trial unloading gradients are generated by discrete sampling within the allowable adjustment range; the cylinder space vector is extracted and the trial unloading gradient is converted into a local pressure relief vector; Extract the pre-set load transfer coefficient of the structure, map the local pressure relief vector to the load transfer coefficient, calculate and derive the change in structural reaction force, and generate a virtual pressure relief response; Extract the force balance benchmark, input the virtual decompression response into the preset evaluation function to solve the evaluation cost value; compare the evaluation cost value to extract the minimum value to determine the optimal decompression timing sequence, and substitute the optimal decompression timing sequence into the pulse width modulation algorithm to generate the unloading action sequence executed at the bottom layer.

6. The hydraulic synchronous sliding control method for nuclear power steel roof truss installation according to claim 5, characterized in that: The method for solving the evaluation value is as follows: Read the current bearing capacity and rated bearing capacity of adjacent sliding support points, calculate the difference between the rated bearing capacity and the current bearing capacity, and use it as the force balance benchmark; Retrieve the preset evaluation function, which sets the pressure relief resistance weight and the structural safety weight. For each virtual pressure relief response, the quotient of the target pressure reduction amplitude and the maximum pressure reduction amplitude in the allowable adjustment range is calculated to obtain the pressure reduction depth coefficient. The pressure reduction depth coefficient is then multiplied by the pressure relief resistance weight to obtain the efficiency cost component. Extract the structural reaction force change contained in the virtual decompression response, and take the equivalent scalar value of the structural reaction force change in the force direction of the adjacent sliding support; Calculate the quotient between the equivalent scalar value and the force equilibrium benchmark, and multiply the quotient by the structural safety weight to obtain the risk cost component; By adding the efficiency cost component and the risk cost component, the evaluation value of the corresponding virtual decompression response is calculated.

7. The hydraulic synchronous sliding control method for installing steel roof trusses in nuclear power plants according to claim 1, characterized in that: The process for assessing the state of resistance elimination is as follows: Injecting a flexible decoupling command switches the global synchronization loop between the hidden off-center load node and the hydraulic main control system to impedance control mode, and loads the unloading action sequence to drive the hidden off-center load node to perform micro-motion pressure reduction. The final stable oil pressure during the micro-pressure reduction process is collected, and the actual unloading amplitude is calculated by combining it with the initial original oil pressure. The pressure release rate waveform is read and feature extraction is performed to calculate the number of polarity reversals, the final pressure release deviation, and the time span for the derivative to return to zero. Feature splicing is then performed to generate a multi-dimensional waveform feature vector. Calculate the spatial characteristic distance between the waveform feature vector and each preset standard evolution centroid, select the optimal matching target based on the minimum value, and output the current resistance elimination state of the implicit off-center load node.

8. The hydraulic synchronous sliding control method for nuclear power steel roof truss installation of claim 1, wherein: Also includes: Based on the analysis of the resistance elimination state, the displacement lag deviation of the hidden off-center load node caused by the independent pressure reduction is analyzed, and the displacement lag deviation is converted into a resynchronization compensation amount. Based on the resynchronization compensation amount, the dynamic rate is redistributed to all sliding support points and the global synchronization state is restored.

9. The hydraulic synchronized sliding control method for nuclear power steel roof truss installation of claim 8, wherein: The method for converting the resynchronization compensation amount is as follows: Read the real-time travel coordinates of the hidden off-center load node and the normal operation support point, use the vector difference algorithm to calculate the spatial deviation of the real-time travel coordinates, and derive the displacement hysteresis deviation. Using the resistance elimination state as an index, the state compensation coefficient is extracted from the preset mapping relationship by looking up a table; and based on the displacement hysteresis deviation and the state compensation coefficient, the resynchronization compensation amount is calculated and generated using a closed-loop feedback adjustment algorithm.

10. A hydraulic synchronous sliding control system for nuclear power steel roof truss installation, used to realize the hydraulic synchronous sliding control method for nuclear power steel roof truss installation in any one of claims 1-9, characterized in that, Includes the following modules: Off-center load identification module: used to synchronously collect oil pressure changes and stroke increments to generate resistance response characteristics; by comparing the deviation of the resistance response characteristics with the normal operating benchmark, hidden off-center load nodes are identified. Interval construction module: used to extract the current load sharing ratio of implicit off-center load nodes and adjacent supports, analyze the additional deformation internal forces of steel roof trusses, and delineate the allowable adjustment range of implicit off-center load nodes. Pressure relief adjustment module: used to construct multiple sets of trial unloading gradients for implicit off-center load nodes within the allowable adjustment range, analyze and generate corresponding virtual pressure relief responses; evaluate the matching degree between the virtual pressure relief responses and the preset force balance benchmark, select the optimal pressure relief timing sequence, and generate unloading action sequence; Status assessment module: used to drive the implicit load node to break away from the global synchronization constraint and perform micro-voltage reduction independently according to the unloading action sequence, and obtain the actual unloading amplitude fed back by the implicit load node; Assess the current resistance elimination status of the implicit off-center load node based on the actual unloading amplitude; State recovery module: It is used to analyze the displacement hysteresis deviation of the hidden off-center load node based on the resistance elimination state analysis, and convert the displacement hysteresis deviation into the resynchronization compensation amount; based on the resynchronization compensation amount, it redistributes the dynamic rate of all sliding support points and restores the global synchronization state.

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