36 results about "Iterative method" patented technology

The application belongs to the field of gear transmission system squeeze film damper damping, especially relates to a kind of gear squeeze film damper damping quick calculation method and system, obtains the structural parameter of squeeze film damper, carries out velocity calculation and constructs the Reynolds equation of squeeze film damper oil film pressure;Based on half-step center finite difference method, the Reynolds equation is solved, and the oil film distribution pressure of oil film damper is obtained;Based on oil film distribution pressure, the oil film counterforce of oil film damper is calculated using double integral algorithm.Compared with the classical short bearing approximate solution and long bearing approximate solution, its use range is wide, and compared with super relaxation iteration method, its calculation efficiency is high.Make it can be used in gear dynamics model to carry out damping analysis.When solving fluid Reynolds equation by finite difference method, only the working condition with regular boundary condition can be processed.Based on variational principle and Galerkin method, a new more general finite element method is proposed to calculate the oil film counterforce of SFD.

This invention discloses a method for calculating the flow rate of a single compressor in a continuous wind tunnel parallel compressor system, relating to the field of supersonic wind tunnel operation and commissioning. The invention uses the mass flow rate of the wind tunnel nozzle as a benchmark for the total flow rate; pre-determines the constant-speed total pressure ratio performance curves of each individual compressor and parameterizes them into a continuous constant-speed total pressure ratio performance mathematical model; during wind tunnel operation, the rotational speed and total pressure ratio of each compressor are measured in real time, and the reduced flow rate is obtained by solving inverse functions or using iterative methods. The initial mass flow rate of each compressor is calculated by combining the inlet total pressure and inlet total temperature; finally, corrections are made based on the deviation between the nozzle mass flow rate and the sum of the initial mass flow rates of each compressor to obtain the actual mass flow rate of each compressor. This achieves accurate determination of the flow rate of each individual compressor in parallel operation, providing a guarantee for the establishment of the target flow field and operational safety in the wind tunnel test section.

The application belongs to the technical field of electromagnetic modeling of targets in layered media, and specifically provides a plane multilayer medium electromagnetic scattering modeling method based on layered medium Green function, which is used to solve the problems of large number of unknown quantities and low calculation efficiency when analyzing the electromagnetic scattering characteristics of targets in layered media; first, the medium target in the plane multilayer medium is meshed; then, the layered medium Green function is calculated based on the space list and interpolation method, and the matrix equation of the target current and magnetic current is constructed by solving the surface integral equation of the target by using the method of moments; finally, the improved stacked non-diagonal low-rank matrix is used to solve the matrix equation to calculate the target scattering field. The application adopts a direct solving calculation method, effectively solves the problem of ill-conditioned matrix difficult to converge in the conventional iterative method, especially for the multi-port excitation problem, without the need for repeated calculation, improving the solving efficiency of large-scale problems and reducing the consumption of calculation resources.

The present invention relates to computer implemented adaptive and iterative methods to improve and accelerate a quality control decision or a performance test in a specific technical field while reducing the overall cost of the quality control or performance test process, respectively; the method comprising: constructing a sequential test; iterating the following steps using the sequential test until a decision is made, obtaining a set of samples, checking the decision of the criteria for the set of samples, determining in an adaptive way the optimal number of additional data samples required for the subsequent iterative step if no decision has been made in the current iteration.

This application provides a method, apparatus, and computer equipment for predicting the carbon dioxide diffusion coefficient in heavy oil enhanced oil recovery, relating to the field of oil and gas development technology. The method is based on Fick's law and the law of conservation of mass. It determines the saturated carbon dioxide concentration in heavy oil through carbon dioxide diffusion experiments. Simultaneously, it considers the volume expansion of heavy oil caused by carbon dioxide dissolving in it, and the oil relative flow opposite to the carbon dioxide diffusion direction caused by this volume expansion. Based on this, a partial differential equation is established to obtain a carbon dioxide diffusion model. The experimentally obtained saturated carbon dioxide concentration in heavy oil is used as the constraint condition for constructing the carbon dioxide diffusion model. The carbon dioxide diffusion model considers the volume expansion change of heavy oil as a one-dimensional expansion change, that is, the volume expansion change of heavy oil is considered through the change in the heavy oil liquid level. Finally, an iterative method is used to obtain a numerical solution. The above method achieves reliable and accurate prediction of the carbon dioxide diffusion coefficient.

This invention relates to the field of wind power equipment monitoring and parameter identification technology, and particularly to a method and apparatus for screening and identifying operating conditions and parameters of wind turbine generators. During grid-connected operation, voltage and current at the grid connection point are collected, and a sliding data window is constructed according to the sampling period. A nonlinear state-space reference model containing the control parameters to be identified is established, and the current response within the window is calculated. Based on the model, the dynamic sensitivity of each parameter to be identified is calculated, and a Fisher information matrix is ​​constructed and accumulated. Completeness indicators such as the condition number are calculated on the Fisher information matrix and compared with a threshold, retaining valid data segments and discarding invalid ones. A nonlinear least-squares identification problem is constructed using only the valid data segments, and the proportional and integral parameters of the phase-locked loop and each control link of the converter are output using a damped Gauss-Newton iterative method. This method eliminates the need for shutdown frequency sweeping or manual fault injection, and utilizes daily random disturbances to achieve automatic screening of operating conditions, improving identification accuracy and reducing testing and data processing costs.

The application discloses a kind of vertical deformation coordination control and pre-offset construction method and system of super-high special-shaped steel bridge tower, method includes: according to the time-varying deformation difference of steel and concrete, construct vertical difference deformation analysis model, calculate the vertical deformation difference of bridge tower full cycle, provide basis for pre-offset calculation;Combined with deformation difference, establish the pre-offset calculation system with the minimum deformation difference as the goal, and the improved nonlinear iterative calculation method is used to determine the construction reverse pre-offset amount in reverse direction.The iterative method takes the minimum sum of deformation difference as the goal, combines time effect and deformation data, adjusts step length and updates pre-offset amount to meet convergence requirements, while dividing stages according to construction nodes, establishing adaptive fitting function to ensure connection, reflecting nonlinear evolution of deformation.Pre-offset amount is segmented and constructed synchronously, and the posture is calibrated, linear is monitored in real time, and the difference deformation is offset by pre-offset deformation.

The application discloses a kind of space target pointing iterative calculation method and system of strapdown, belong to communication and measurement control technical field.The application is installed on the azimuth rotating platform of horizontal tracking frame by heading angle output angle as azimuth feedback information by heading angle output angle as azimuth feedback information, combined with the geographical pointing angle of space target, the theoretical heading angle when horizontal tracking frame points to space target is calculated using iterative method, and the corresponding heading angle correction method is provided.The application is installed on the azimuth rotating platform of horizontal tracking frame by the method that heading angle output angle as azimuth feedback information is output as feedback information, avoids the azimuth axis angle initialization process, effectively reduces the start-up time of horizontal tracking frame, with the advantages of no need to increase additional hardware, simple implementation, wide application range.

This invention discloses a high-precision prediction method for high-speed turbulent boundary layer friction based on compressible transformation, belonging to the field of fluid mechanics engineering calculation and experimental technology. Specifically, the method involves: 1) Obtaining the basic parameters of the zero-pressure gradient compressible flat plate turbulent boundary layer to be predicted, including the incoming Mach number, momentum-thickness Reynolds number, Prandtl number, incoming reference temperature, wall temperature, recovery temperature, and viscosity index; 2) Setting the initial iteration values, convergence criteria, and maximum iteration steps for numerical calculation; 3) Pre-calculating the values ​​of the auxiliary function in the improved drag transformation model over the specified interval, as well as the ratio of free-flow velocities before and after the transformation; 4) After the pre-calculation, using an iterative method to solve for the target parameters in the improved drag transformation model; 5) Calculating the wall friction coefficient and heat flux coefficient based on the obtained target parameters and basic parameters. This method can achieve rapid and high-precision prediction of the wall friction coefficient and heat flux coefficient under a wide range of Mach numbers and complex wall heat transfer conditions, demonstrating significant engineering practicality.

This invention discloses a method and device for measuring the flow rate of a condensate feedwater system oriented towards edge computing. The method includes the following steps: Step S1, extracting pump operating parameters under multiple typical operating conditions from a historical database of an industrial internet platform; Step S2, performing simulation modeling of the condensate feedwater system, and constructing a nonlinear mapping relationship between the pipe resistance coefficient and flow rate by combining the pipe geometry, fluid properties, and pump mechanical characteristics, thus obtaining the pipe resistance equation; Step S3, simultaneously solving the pipe resistance equation and the centrifugal pump head-flow characteristic equation using the Newton-Raphson iterative method to obtain the theoretically calculated flow rate value; Step S4, comparing the theoretically calculated flow rate value with the real-time measured flow rate value, and dynamically adjusting the model parameters to ensure that the model error is less than a set threshold. This invention achieves high accuracy in measuring the flow rate of the condensate feedwater system.

The application relates to the technical field of nonlinear dynamics analysis of an offshore engineering riser, and provides a deepwater riser configuration and hydrodynamic synchronous bidirectional coupling solving method to solve the problems that the method based on a small-angle beam unit in the prior art is poor in precision and large in calculation amount due to insufficient geometric nonlinear description capability, and the ANCF coupling method in the prior art loses the advantage of a constant mass matrix and is low in calculation efficiency due to frequent updating of an additional mass matrix. The method comprises the following steps: S100, establishing a riser nonlinear dynamics model based on an absolute node coordinate method; S200, explicitly expressing nonlinear hydrodynamic loads based on an implicit time domain integral method; and S300, synchronously solving riser nonlinear dynamics response by adopting a Newton-Raphson iteration method.

This invention relates to the field of industrial pump monitoring technology, and discloses a method and system for estimating the flow rate of a centrifugal pump based on curve fitting. The method acquires the head-flow characteristic curve and historical operating data provided by the centrifugal pump at the time of manufacture, and fits the characteristic curve into a mathematical model; it collects the pressure signal at the centrifugal pump outlet and the ambient temperature signal of the centrifugal pump, obtains the current density of the medium being pumped by the centrifugal pump, and converts the pressure signal into a head value that takes density and altitude correction into account; it substitutes the head value into the fitted mathematical model, solves the inverse function using Newton's iteration method, and obtains the estimated flow rate; it adaptively corrects the estimated flow rate according to a preset correction algorithm to obtain the final flow rate value; it determines the operating range of the centrifugal pump based on the estimated flow rate and head value; it calculates the operating efficiency of the centrifugal pump based on the estimated flow rate and head value, and provides energy efficiency optimization suggestions based on the efficiency value.

The application discloses a profile error calculation method for a numerical control machining device, and relates to the technical field of numerical control machining.The method takes a time point corresponding to an expected position point as an initial value of a Newton iteration method, determines a potential time interval in which a time point corresponding to a minimum value of a profile error evaluation function is located by using a gradient descent method, and then dynamically switches the Newton iteration method and a dichotomy method to accurately solve a target time point in the potential time interval, so that the method quickly and reliably converges to a local optimal point closest to the expected position point.The method has the speed of the Newton iteration method and the stability of the dichotomy method, improves the reliability and robustness of a profile error calculation result, and provides an efficient and stable calculation basis for subsequent profile precision control and real-time compensation.

This invention relates to the field of wind power equipment monitoring and parameter identification technology, and particularly to a method and apparatus for screening and identifying operating conditions and parameters of wind turbine generators. During grid-connected operation, voltage and current at the grid connection point are collected, and a sliding data window is constructed according to the sampling period. A nonlinear state-space reference model containing the control parameters to be identified is established, and the current response within the window is calculated. Based on the model, the dynamic sensitivity of each parameter to be identified is calculated, and a Fisher information matrix is ​​constructed and accumulated. Completeness indicators such as the condition number are calculated on the Fisher information matrix and compared with a threshold, retaining valid data segments and discarding invalid ones. A nonlinear least-squares identification problem is constructed using only the valid data segments, and the proportional and integral parameters of the phase-locked loop and each control link of the converter are output using a damped Gauss-Newton iterative method. This method eliminates the need for shutdown frequency sweeping or manual fault injection, and utilizes daily random disturbances to achieve automatic screening of operating conditions, improving identification accuracy and reducing testing and data processing costs.

The application discloses a motion control method and device of a humanoid lower limb exoskeleton robot and a storage medium, and relates to the technical field of industrial robots. For a humanoid lower limb exoskeleton robot with the third, fourth and fifth joint rotation axes being parallel to each other, the method comprises the following steps: receiving a foot end desired pose to obtain a target pose matrix; constructing an algebraic equation to analytically solve a first joint angle; based on this, sequentially decoupling and calculating the angles of the space-related joints and the parallel-axis group joints; and finally converting the angles into cooperative driving instructions. Through a step-by-step decoupling analytical solving strategy, the application avoids problems such as matrix singularity and iteration non-convergence existing in traditional numerical iteration methods, can efficiently, accurately and stably obtain the rotation angles of each joint of the robot, and thus realizes precise and robust control of the exoskeleton robot with a specific configuration.

The present application relates to a kind of railway rail corrugation development and evolution calculation method, establish multi-body dynamics model and frequency domain three-dimensional vehicle track dynamics model, wherein the multi-body dynamics model is used to calculate the quasi-static force of wheel rail, the frequency domain three-dimensional vehicle track dynamics model calculates the dynamic wheel rail lateral force and vertical force;According to the lateral and vertical force of wheel rail, the roughness change caused by wheel rail dynamic interaction is simulated, the calculated roughness change is added to the initial roughness, and the final rail corrugation state is calculated by iterative method.The present application has the advantages of: fast calculation speed, can reveal the mechanism of corrugation generation;It has a wide range of application scenarios, and can be applied to the evaluation of newly-built line, rail corrugation management in existing line.

The embodiment of the present application provides an automatic iteration method of a trajectory prediction model. The method comprises the following steps: receiving prediction scene data determined by a trajectory prediction model of a mobile device; storing the prediction scene data into a cloud scene library, and performing data shunting on all scene data in the cloud scene library to distinguish normal scene data and abnormal scene data; respectively performing perception labeling on the normal scene data and the abnormal scene data to obtain trajectory prediction training samples with labels; training the trajectory prediction model in the cloud based on the trajectory prediction training samples with labels; and downloading parameters of the trained trajectory prediction model to the mobile device to update and iterate the trajectory prediction model of the mobile device. The embodiment of the present application adopts a mode of cloud training based on vehicle-side reasoning, automatically collects valuable data in a targeted manner, and automatically completes data labeling, thereby improving the efficiency of iteration of the trajectory prediction model of the vehicle-side of the autonomous vehicle.

This invention discloses a parametric design and iterative optimization design method and system for building structural morphology. The method includes the following steps: S1: Converting the architectural design surface into a structural analysis model; S2: Determining the direction vector of the principal axis section of the components; S3: Calculating the β angle; S4: Importing the structural analysis model and member information into finite element analysis software to establish an initial spatial reticulated shell model; S5: Iteratively optimizing the spatial reticulated shell model and simultaneously correcting the node coordinates and β angle to obtain the initial geometric model; S6: Iterative construction simulation analysis; S7: High-precision initial state reverse engineering based on construction steps; S8: Determining the initial alignment using the structural design form-finding logic; S9: Detailed design and delivery. Through the above parametric design and iterative method, the architectural surface is accurately matched, ensuring that the morphology of the completed structure approximates the architect's design intent to the greatest extent possible.

The application discloses a MIMO scattering channel estimation method, medium and equipment, and belongs to the technical field of channel estimation. The method comprises the following steps: obtaining a noisy scattering channel matrix, performing reverse diffusion denoising processing on the basis of a trained DT denoising model according to the noisy scattering channel matrix, and outputting a denoised scattering channel matrix; and using a training data set, a verification data set and a test data set to train the DT denoising model to output the denoised scattering channel matrix through an iterative method and a reverse denoising process. The application solves the defects that the prior art has not effectively applied the diffusion model to the tropospheric scattering channel estimation field and has not proposed a special generative model architecture optimized for the scene characteristics.

The application provides an intelligent selection method and system for an iterative method for a sparse linear system, wherein after receiving a coefficient matrix and a right end term of a system to be solved, an extended multi-channel coding strategy is used to code the matrix to generate a two-dimensional image, and the right end term is coded to generate a one-dimensional image; subsequently, the features of the matrix and the right end term are extracted through a convolution network respectively, and the obtained feature maps are tokenized; a multi-head self-attention mechanism is used to explicitly capture the internal structure of the matrix, the characteristics of the right end term and the dependency relationship between the two, obtain global tokens, integrate the global tokens into the feature maps, and finally classify the feature maps integrated with the global information to predict the optimal iterative method. Through the whole system representation and global context modeling, the accuracy and robustness of the iterative method selection are effectively improved, and the application is especially suitable for solving complex engineering problems with global dominant characteristics.

The application discloses an engine mixed-dimension parallel simulation method and system, adopts an iterative method to solve a nonlinear equation group composed of an engine common working equation group and free variables, and obtains a simulation result; the iterative method comprises the following steps: determining a mixed-dimension scheme used in each round of iteration at the beginning of each round of iteration; splitting each round of iteration simulation task into multiple simulation tasks; driving the calculation tasks of each component according to an asynchronous processing relationship in each simulation task, wherein the asynchronous processing relationship is to organize a calculation flow in a single simulation task in an event-driven mode; and when any simulation task is completed, assembling a Jacobian matrix based on a hierarchical fault-tolerant strategy according to the simulation result of the simulation task. The application can improve the calculation efficiency of the Jacobian matrix in the engine mixed-dimension simulation, improve the robustness of the simulation calculation, and improve the portability of the system.

This invention relates to the field of geophysical exploration technology, specifically to a well-to-surface electromagnetic forward modeling method, apparatus, and storage medium. The method includes: S1, modeling based on an octree mesh; S2, constructing vector Nédélec basis functions on the elements based on Gauss integration points and Gauss-Legendre-Lobatto (GLL) integration points set in the elements; S3, deriving the governing equations of the well-to-surface electromagnetic finite element method starting from Maxwell's equations; S4, constructing block diagonal preconditions and solving using an iterative method; S5, after exiting the iteration, calculating the electromagnetic response using the iterative model. This invention significantly reduces the number of elements in the mesh while maintaining model accuracy, thereby reducing computational costs. Higher-order shape functions are constructed and used in the forward modeling calculation to improve the accuracy of the numerical solution.

This invention provides a method for calculating the axial compression bearing capacity of short welded box-section columns in curved steel structures based on dual nonlinear analysis of beam-column theory and geometric materials, belonging to the field of bearing capacity calculation for curved steel components. It addresses the problems of existing steel structure bearing capacity calculation methods, such as material waste, poor economy, complex modeling, high calculation costs, long calculation times, and inconvenience for parametric research and summarizing design principles. Starting from the basic governing equations of beam-column theory, this invention introduces precise initial geometry, a bilinear elastoplastic material constitutive model, and uses the Galerkin weighted residual method for spatial discretization. Combined with the Newton-Raphson iterative method and arc length control technology, it achieves nonlinear response tracking of the entire process of the component from loading onwards, through material yielding, to reaching its ultimate bearing capacity.

This invention provides a method for estimating heat transfer in furnace rollers based on a partitioned simplified model, belonging to the field of industrial furnace equipment design and thermal analysis technology. The method includes: First, dividing the furnace roller structure axially into independently calculated refractory material regions and roller ring regions; second, geometrically simplifying the complex roller ring structure by using the equivalent thickness method to handle the variable cross-section flanges and introducing a perforation coefficient to represent the radially perforated structure; then, based on the simplified model, defining multiple independent heat transfer paths from the furnace chamber to the cooling water; next, for each path, applying classical analytical formulas for radiation, conduction, convection, and cooling water heat absorption to establish a closed set of equations; finally, inputting specific geometric, material, and operating parameters, and using an iterative method to solve the equations simultaneously to obtain the temperature distribution and heat transfer at key locations on the furnace roller. This invention significantly improves computational efficiency and model flexibility while ensuring a certain level of engineering calculation accuracy.

This invention discloses a trajectory planning method for adjusting the visibility time and uncertainty of a spacecraft, relating to the field of spacecraft technology. The method includes: establishing a spacecraft dynamics model considering perturbations and a geometric visibility constraint model for a situational awareness device; defining a vertex-crossing detection angle as an intermediate variable relating the spacecraft's visibility time and state uncertainty; solving for the vertex-crossing detection angle of the spacecraft relative to the situational awareness device based on latitudinal argument matching and Newton's iteration method; constructing an optimization problem using the spacecraft's pulse velocity increment as the optimization variable and maximizing or minimizing the square of the vertex-crossing detection angle as the optimization objective, and numerically solving it using a sequential quadratic programming algorithm to obtain the optimal pulse velocity increment; and performing spacecraft orbital maneuvers based on the optimal pulse velocity increment. This invention can establish the relationship between the orbital maneuver vector and the detected characteristic indicators, enabling rapid optimization of the spacecraft maneuver vector.

This invention discloses a method and system for coordinated vertical deformation control and pre-deflection construction of ultra-high irregular steel-concrete bridge towers. The method includes: constructing a vertical differential deformation analysis model based on the time-varying deformation differences between steel and concrete, calculating the vertical deformation difference of the bridge tower throughout its entire lifecycle, and providing a basis for pre-deflection calculation; establishing a pre-deflection calculation system with the goal of minimizing the deformation difference, and using an improved nonlinear iterative calculation method to determine the reverse pre-deflection during construction. This iterative method aims to minimize the total deformation difference, and adaptively adjusts the step size and updates the pre-deflection until it meets the convergence requirements, taking into account time effects and deformation data. Simultaneously, it divides the construction into stages according to construction nodes, establishes a fitting function to ensure seamless connection, and reflects the nonlinear evolution of deformation. Construction is carried out synchronously in segments according to the pre-deflection, and the attitude is calibrated. The alignment is monitored in real time, and the pre-deflection deformation is used to offset the later differential deformation.

This invention relates to the field of capacitance calculation technology and discloses a fast algorithm for extracting parasitic capacitance in large-scale integrated circuits. This method combines the method of moments (MoM), a fast multipole algorithm for layered dielectrics, and overlapping region decomposition preprocessing techniques to construct a complete parasitic capacitance extraction solution. By directly introducing the Green's function for the layered dielectric, the numerical solution strictly satisfies the electric field transport conditions at the dielectric interface, and the electrostatic problem in the layered dielectric is transformed into boundary integral equations defined on the interconnect surface. Subsequently, the MoM is used to discretize these boundary integral equations, resulting in a large-scale dense system of linear algebraic equations. To improve solution efficiency, an efficient preprocessing strategy based on overlapping region decomposition is further designed, and combined with the matrix-free minimum residual iteration method and the layered fast multipole algorithm, achieving efficient solution with low computational and storage overhead.

This application provides a method, apparatus, electronic device, and storage medium for constructing an IVCPS requirement element knowledge base. The method includes: processing preset file data using the Stanford seven-step method and iterative method to generate ontology models of different elements; extracting entities and relations from the ontology models using an entity and relation extraction algorithm to obtain a knowledge graph corresponding to the ontology model; determining the association relationships between different knowledge graphs using a preset association algorithm; and obtaining an IVCPS requirement element knowledge base based on multiple knowledge graphs and the association relationships between them. This IVCPS requirement element knowledge base allows for the analysis of different requirements for different elements, improving the accuracy of requirement analysis.