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31 results about "Euler method" patented technology

Euler's method is a numerical method to solve first order first degree differential equation with a given initial value. It is the most basic explicit method for numerical integration of ordinary differential equations and is the simplest Runge–Kutta method. The Euler method is named after Leonhard Euler, who treated it in his book Institutionum calculi integralis (published 1768–1870).

Series industrial robot external force estimation method

The invention discloses a series industrial robot external force estimation method, and the method comprises the following steps: S1, constructing a series industrial robot kinetic equation model incorporating a kinetic residual error through a Newton-Euler method; s2, fitting the dynamic residual error and noise of the robot by using a variational approximate Gaussian process; s3, constructing an external force estimation discrete state equation; s4, constructing an adaptive Kalman filter; and S5, solving the external force through Kalman iteration. The external force applied to the robot can be estimated, the external force and collision applied to the robot can be detected under the condition that the robot is not provided with a six-dimensional force or torque sensor, the detection precision and response speed of external force estimation are improved, and the method can be used for industrial scenes such as robot assembly and polishing.
Owner:SOUTH CHINA UNIV OF TECH

Battery network state calculation method and device, equipment, medium and product

The invention discloses a battery network state calculation method and device, equipment, a medium and a product, and relates to the technical field of battery network state calculation. The method comprises the following steps: firstly, constructing a dynamic reconfigurable network of a battery system based on a topological structure of the battery system; dividing the dynamic reconfigurable network into a plurality of sub-networks; then respectively constructing a state space equation of each sub-network; and then solving the state-space equation of each sub-network based on an improved Euler method to obtain the state quantity of each sub-network at different time steps. According to the method, the dynamic reconfigurable network is divided into a plurality of mutually independent sub-networks, the overall state calculation of the battery network is converted into the state calculation of the plurality of sub-networks, the calculation amount and the calculation complexity are effectively reduced, the Euler calculation of two stages is used for evaluation, and the accuracy of a numerical solution is improved.
Owner:HUADIAN INNER MONGOLIA ENERGY CO LTD +2

Anisotropic large-scale structure attitude adjustment trajectory planning method

The invention provides an anisotropic large-scale structure attitude adjustment trajectory planning method which specifically comprises the following steps: firstly, carrying out dynamic modeling on an attitude adjustment mechanism by adopting a Newton-Euler method so as to calculate driving force of each shaft of a positioner during attitude adjustment of a large-scale structure; dividing the attitude adjustment track into an acceleration section, a constant speed section and a deceleration section, fitting the attitude adjustment track by using a quartic polynomial, and calculating track parameters of the large structure in different directions; and finally, constructing a positioner driving force and speed constraint model, and performing attitude adjustment duration search by adopting a dichotomy, thereby improving the efficiency of attitude adjustment of the large-scale structure. According to the method, different time parameters (the proportion of a constant-speed section) are adopted for planning the motion trails of the large-scale structure in different directions, the performance of a servo control system can be brought into full play, and therefore the attitude adjustment efficiency of the large-scale structure is improved.
Owner:NANJING VOCATIONAL UNIV OF IND TECH

Self-driving automobile speed tracking cooperative control method based on layered MPC and fuzzy PID

PendingCN121062709AFuzzy ruleMaster cylinder
The invention belongs to the technical field of automatic driving automobile speed tracking, and particularly relates to an automatic driving automobile speed tracking cooperative control method based on hierarchical MPC and fuzzy PID, comprising the following steps: S1, constructing a longitudinal dynamic model of an automatic driving automobile; s2, designing a fuzzy rule; s3, obtaining a discrete system state equation by using a forward Euler method; s4, determining that the output of the system at the future moment is expressed in a matrix form; s5, converting an MPC problem and a quadratic programming problem; s6, the execution control layer converts the expected acceleration into throttle valve and brake master cylinder pressure control quantity through fuzzy self-adaptive PID; and S7, switching logic is adopted to judge driving / braking control, and speed tracking control is carried out. According to the method, buffeting can be effectively suppressed on the premise of ensuring that the system can reach a stable state, high robustness to external disturbance is achieved, and speed tracking of the self-driving automobile is ensured.
Owner:CHANGCHUN UNIV OF SCI & TECH

Method for calculating temperature of turbine rotor and stator in transition state of aero-engine

The invention relates to the technical field of aero-engine transition state characteristics and control process temperature calculation, in particular to a cooling-considered aero-engine transition state turbine rotor and stator temperature calculation method. An independent differential equation is established by introducing a hot side fuel gas and cold side cooling air double-heat-source model, and the method is suitable for an aero-engine scene with a complex cooling structure; a lumped parameter method is adopted to reasonably simplify a three-dimensional heat conduction equation, on the premise that the engineering precision of a component with the small Bi number is guaranteed, temperature distribution is simplified into a uniform field, the calculation dimension is remarkably reduced, in combination with an explicit Euler method numerical integration method, rapid discrete solving of a differential equation is achieved, the real-time requirement of an airborne model for transition state calculation is met, and the calculation efficiency is improved. And the time step length is adaptively adjusted to guarantee the numerical stability. By outputting the rotor / stator temperature of the turbine in real time, the dynamic heat exchange effect of the metal component and the airflow in the transition state can be accurately evaluated, and engine control law design and stability optimization are supported.
Owner:NORTHWESTERN POLYTECHNICAL UNIV

Unmanned tracked vehicle trajectory tracking method based on H infinity and model prediction hybrid control

The invention discloses an unmanned tracked vehicle trajectory tracking method based on H infinity model prediction hybrid control, which comprises the following steps: firstly, establishing a tracked vehicle dynamics model, and discretizing through a forward Euler method; an H infinity and MPC double-controller parallel computing architecture is adopted, and an MPC controller combines a reference trajectory and a prediction state to generate an optimal control quantity of an adaptive constraint through rolling optimization to minimize a tracking error and a control cost; multi-source interference is introduced into the H infinite controller, and disturbance compensation control quantity is generated through interference modeling, linear processing and Riccati equation solving; and the optimal control quantity and the disturbance compensation control quantity are fused, a crawler executing mechanism is driven, a new state is fed back, and closed-loop feedback control is achieved. The method not only has the dynamic optimization capability of the MPC controller, but also has the strong anti-interference capability of the H infinite controller, realizes synchronous consideration of optimization and robustness, and ensures that the system always keeps trajectory tracking precision and stability under complex working conditions through closed-loop feedback control.
Owner:INNER MONGOLIA YUANENG PHOTOSYNTHETIC TECHNOLOGY CO LTD

Adaptive simulation prediction method, system, medium and product for gas-solid two-phase flow

The application discloses a kind of gas-solid two-phase flow self-adapting simulation prediction method, system, medium and product, belong to the field of digital simulation of fluid dynamics, the method is: obtaining industrial equipment geometry, particle and fluid data, constructs gas-solid two-phase flow CMPPIC model;Wherein, continuous phase is with Euler method, discrete phase is with Lagrange particle bag representation;Perform time advance iteration to termination condition, output result, wherein each round of iteration includes mapping particle bag data to Euler cell, obtaining particle statistical information and marking fixed state particle according to rules;Freeze fixed cell particle volume fraction, calculate porous medium parameter, reconstruct its continuous phase momentum conservation equation;Based on reconstruction and unreconstructed equation, update flow field, while updating the particle motion of unmarked fixed state cell. By implementing the application, the problem that calculation efficiency and physical precision are difficult to consider in simulating fixed particle structure in the prior art can be solved.
Owner:SUN YAT SEN UNIV

Fluid-solid coupling calculation method for predicting vortex-induced motion response of underwater single anchor system

PendingCN121997815AAccurate six degrees of freedom coupled motionReal-time visualizationGeometric CADDesign optimisation/simulationEulerian methodFluid solid coupling
The invention discloses a fluid-solid coupling calculation method for predicting the vortex-induced motion response of an underwater single anchor system, and the method comprises the steps: dividing a flow field calculation domain based on a multi-region overlapping grid technology, and achieving the data transmission through boundary point interpolation; establishing an anchor chain discrete dynamical model by adopting a concentrated mass method, and iteratively solving an anchor chain form and tension distribution; a six-degree-of-freedom rigid body dynamic model of the mooring body is established by applying a Newton-Euler method, and constraint conditions such as hydrodynamic force and anchor chain tension are integrated; a flow field is solved through a computational fluid dynamics method, and bidirectional data exchange of fluid load, anchor chain tension and structural motion is realized by using a custom function. The method has the advantages that the problem of large-displacement motion simulation of the mooring system is effectively solved through a multi-region overlapping grid and a cross-platform collaborative architecture, the six-degree-of-freedom vortex-induced motion response of the mooring body can be predicted in a high-precision mode, and whole-process visualization of dynamic changes of a flow field is achieved.
Owner:NORTHWESTERN POLYTECHNICAL UNIV

Urban pavement rainfall runoff particulate matter transmission rate calculation method based on concept of control layer

PendingCN121636881AComplex mathematical operationsRainfall runoffEulerian method
The invention provides an urban pavement rainfall runoff particulate matter transmission rate calculation method based on a control layer concept, and the method comprehensively considers the influence of raindrop splashing and runoff shearing composite driving effect on particulate matter transmission by establishing a double-layer conceptual model comprising a static control layer and a dynamic runoff layer. The particulate matter concentration change process under the action of different driving forces is solved through a mass conservation equation, a slope rainfall runoff analytical solution equation is combined, an improved Euler method is adopted for numerical solution, and accurate calculation of the urban pavement particulate matter transmission rate is achieved. According to the method, traditional empirical parameters are converted into variables with clear physical significance, the problems that an existing model is unclear in physical mechanism and low in prediction precision are solved, a scientific basis can be provided for urban runoff pollution load calculation and accurate prevention and control, and the method has the advantages of being clear in physical significance, high in calculation efficiency, good in prediction precision and high in engineering applicability.
Owner:SUZHOU UNIV OF SCI & TECH

A robotic arm pose tracking control method for moving targets

This invention provides a robotic arm pose tracking control method for moving targets, relating to the control of autonomous moving bodies in three-dimensional space and the field of robotics. The control method includes: establishing the second-order pose dynamics equation of the target rigid body according to the Newton-Euler method; establishing the second-order pose dynamics equation of the robotic arm end effector according to the Lagrange equation; obtaining the relative pose dynamics equation based on the second-order pose dynamics equations of the target rigid body and the robotic arm end effector; and designing a robust adaptive controller for the relative pose dynamics equation, enabling the robotic arm end effector to complete the pose tracking control task of the moving target rigid body.
Owner:UNIV OF SCI & TECH BEIJING

Modeling method, system and terminal for electric propulsion aircraft power conversion system

The application belongs to the technical field of hybrid electric propulsion aircraft, and discloses a modeling method, system and terminal for an electric propulsion aircraft power conversion system, four working modes of parallel power converters are determined; the circuit is discretely linearized by using a binary resistance method, and a discrete linearization model of boost and bidirectional DC / DC converters is constructed; node voltage transient equations are listed and written, and the electrical coupling characteristics of the parallel circuit are expressed by state variable coupling; the node voltage transient equation and the electrical coupling characteristic expression are solved by using a numerical method, a matrix equation is obtained, and iterative calculation is completed, and then the mathematical model of the electric propulsion aircraft power conversion system is obtained, and the working state simulation of the converter is realized. The application is based on linear discretization of the circuit and electrical state decoupling, and uses an implicit Euler method to solve the rigid differential equation, so that the accuracy and stability of the solution are obviously improved, and the application has good applicability. The application is supported by a master's postgraduate practice and innovation ability cultivation fund of Northwest Polytechnic University.
Owner:NORTHWESTERN POLYTECHNICAL UNIV +1

Water drop collection coefficient calculation method based on Euler method streamline

The invention provides a water drop collection coefficient calculation method based on an Euler method streamline, and the method comprises the steps: carrying out the modeling of a simulated aircraft part, and carrying out the grid division of a calculation domain; setting boundary conditions, and solving a steady-state air flow field; establishing a steady-state non-conservation form water drop momentum equation by using an Euler method to obtain steady-state water drop velocity field distribution; reading each surface node of the wall grid of the aircraft component, judging the surface node of a water drop impact area according to the water drop velocity field, and solving along the reverse direction of the water drop velocity by taking the node coordinate of the impact area as a starting point and taking the far-field boundary of the computational domain as an end point to obtain a water drop streamline; and sequentially calculating water drop collection coefficients of the wall grids according to the water drop streamlines, and outputting a water drop collection coefficient distribution result of the aircraft component. Compared with a traditional Lagrangian method, the method does not need to determine a water drop release position, and has better applicability and calculation efficiency on a complex surface; compared with a traditional Euler method, the calculation convergence is better, and the calculation of the water drop collection coefficient is more accurate.
Owner:BEIHANG UNIV

A complex system simulation solving method based on hybrid gradient search

The application discloses a complex system simulation solving method based on a hybrid gradient search, and aims at the high-performance simulation solving demand of a system model under a mixed modeling strategy of an explicit mechanism and an implicit model. Under a mechanism description specification based on data and mechanism mixing, three main steps of an automatic optimization step of a solving path based on constraint qualitative information, an automatic transformation step of a differential term based on a robust Euler method and a gray-box system solving step based on a hybrid gradient search are adopted to adaptively establish a solving path of a system-level mechanism model, and high-precision gray-box solving guarantee is provided for a simulation task of the mixed modeling strategy.
Owner:BEIHANG UNIV

Electric formula car dynamic performance optimization method and system, storage medium and equipment

The invention relates to the field of racing car dynamics optimization, and discloses an electric formula racing car dynamic performance optimization method and system, a storage medium and equipment. A Newton-Euler method is adopted to construct an eight-degree-of-freedom vehicle dynamical model including vehicle body longitudinal, transverse, yawing and roll degrees of freedom and four-wheel rotation degrees of freedom, and then a vehicle body mechanical equilibrium equation set, a four-wheel load calculation equation and a four-wheel slip rate and slip angle calculation equation are obtained; based on a car body mechanical equilibrium equation set, a four-wheel load calculation equation and a four-wheel slip rate and slip angle calculation equation, an optimal control problem is determined, the optimal control problem is converted into a nonlinear programming problem and solved, and an optimal racing car track driving control sequence is obtained; and setting particle vectors of vehicle parameters including wheelbase, wheel track and braking force distribution coefficient, and performing iterative optimization on racing track time by adopting a particle swarm algorithm. According to the method, the calculation complexity can be reduced, and the optimization efficiency is improved.
Owner:BEIJING INFORMATION SCI & TECH UNIV

Numerical modeling method for underwater complete axial symmetry space three-wave coupling sound field

A numerical modeling method for an underwater complete axial symmetry space three-wave coupling sound field belongs to the field of nonlinear acoustics, and comprises the following steps: carrying out simple harmonic hypothesis on sound waves, and substituting the sound waves meeting difference frequency three-wave frequency matching conditions into a KZK equation to obtain a difference frequency three-wave coupling equation set; decomposing the equation set into a diffraction equation, a dissipation equation and a nonlinear equation by using a second-order Strong operator splitting method; a diffraction equation is solved by using a chasing method, a dissipation equation is solved by using an accurate analytical solution, and a nonlinear equation is solved by using an explicit Euler method; and setting boundary conditions, and calculating an underwater complete axial symmetry space three-wave coupling sound field. According to the method, a three-wave coupling sound field model is established based on a KZK equation, efficient solving of a three-wave coupling equation set is achieved by utilizing a second-order Strong operator splitting method and combining finite difference and an explicit Euler method, and the three-wave coupling sound field in the underwater complete axial symmetry space is accurately calculated. According to the invention, the calculation complexity is reduced, the calculation efficiency is improved, and the calculation result is accurate.
Owner:HARBIN ENG UNIV

A power point tracking control method for NPC rectifiers with simplified computational complexity

This invention discloses a simplified power point tracking (PPT) control method for NPC rectifiers, comprising: calculating the grid-side complex power S and the differential expression of the negative conjugate complex power based on the mathematical model of the three-level NPC rectifier and instantaneous power theory; discretizing the negative conjugate complex power at time k+1 in the dq rotating coordinate system using the forward Euler method; calculating the power error of the negative conjugate complex power under zero vector action at time k+1; performing preliminary vector pre-selection based on the sector where the power error is located; reducing the number of pre-selected vectors in each group in step four to four; cyclically calculating the predicted active and reactive power values ​​and the cost function J at time k+1, and determining the optimal vector. This invention simplifies the computational workload in the vector selection process of a three-level midpoint clamp rectifier by reducing polling pre-selection vectors, and introduces power point tracking error correction on the basis of traditional PI, thereby achieving accurate power point tracking control.
Owner:CHINA UNIV OF MINING & TECH

A robot friction torque online prediction method and device, and a computer readable storage medium

The application discloses a robot friction torque online prediction method and device and a computer readable storage medium. For a joint type serial industrial robot to be identified, a dynamics model of the robot considering friction is established by using a Newton-Euler method, the dynamics model is linearized, five-term finite Fourier series are used to design an excitation trajectory, joint motion data of the robot under the excitation trajectory are collected to establish a regression equation set, the regression equation set is solved to obtain overall dynamics parameters to be identified, and the friction torque of the robot is calculated online according to the overall dynamics parameters to be identified, so that the friction torque of the robot can be predicted online.
Owner:QKM TECH (DONG GUAN) CO LTD +1

Steering and torque distribution integrated control method for four-wheel independent drive vehicle based on nonlinear predictive control

The invention provides a steering and torque distribution integrated control method for a four-wheel independent drive vehicle based on nonlinear predictive control, which comprises the following steps of: firstly, establishing a nonlinear state-space equation of the four-wheel independent drive vehicle, and establishing an optimal control problem based on the state-space equation; and then the optimal control problem of the original continuous time system is converted into a nonlinear optimization problem by using a forward Euler method and a multiple targeting method, and the singularity of the nonlinear optimization problem is effectively eliminated and the convexity of the nonlinear optimization problem is improved by adding a regular term in an optimization target. Finally, a moderate-scale sequential quadratic programming mode is designed, and compared with the prior art adopting hierarchical nonlinear predictive control, an open source solver IPOPT and the like, the control precision and the solving speed can be effectively improved.
Owner:BEIJING INST OF TECH

A predictive control method, device and medium for an electro-hydraulic servo system

This invention discloses a model predictive control method, device, and medium for an electro-hydraulic servo system, relating to the field of electro-hydraulic servo model prediction technology. The method includes: acquiring data based on the electro-hydraulic servo system; defining a state variable vector based on the resultant force formed by the equivalent chamber pressure difference; discretizing the vector using the forward Euler method; constructing a piston force balance equation; updating the state variable vector data; setting the relationship equation between the valve core opening and the control voltage in the electronic control domain; updating the flow rate of the hydraulic cylinder into the upper and lower chambers; and reconstructing and updating the state variable vector. The method of this invention, through the combined use of the force balance equation in the mechanical domain and the compensation signal in the electronic control domain, allows the voltage change issued by the controller to be equivalent to direct control of the output force. Through the integrated fusion of static mapping functions and dynamic compensation functions, the compensated voltage drive signal can maintain ideal linearity in steady state and correct hysteresis errors in real time during dynamic changes.
Owner:NANJING TOMORROW INTELLIGENT CONTROL TECH CO LTD

Design method, device and equipment of supersonic velocity point convergence nozzle and medium

The invention belongs to the technical field of nozzle design, and relates to a design method, device and equipment of a supersonic velocity point convergence nozzle and a medium. The method comprises the steps that design parameters of the supersonic velocity point convergence nozzle are obtained, a point convergence flow control equation, a supersonic velocity flow characteristic line equation and a compatibility equation are obtained, and an improved Euler method is adopted to obtain a nozzle outlet left row characteristic line and a nozzle throat right row characteristic line; taking the nozzle outlet left-row characteristic line, the nozzle throat right-row characteristic line and the symmetry axis of the nozzle as boundary conditions, and adopting a characteristic line method to obtain a point convergence nozzle flow field; in the obtained point convergence nozzle flow field, the supersonic velocity molded surface of the supersonic velocity point convergence nozzle is obtained by adopting a mass conservation mode along the nozzle throat right row characteristic line; and designing a contraction section of the supersonic velocity point confluence nozzle, connecting the contraction section with the supersonic velocity profile of the supersonic velocity point confluence nozzle, and then correcting to obtain the supersonic velocity sticky point confluence nozzle. The present application can provide supersonic point sink flow.
Owner:NAT UNIV OF DEFENSE TECH

Five-phase motor real-time simulation method and device based on FPGA and considering third harmonic flux linkage equation

The invention relates to a five-phase motor real-time simulation method and device considering a third harmonic flux linkage equation based on an FPGA, and the method comprises the steps: receiving motor and inverter parameters and PWM signals through the FPGA, and generating a motor terminal voltage through a five-phase inverter model; fundamental wave / third harmonic coordinate transformation is carried out on a motor model based on dynamic decoupling, an improved Euler method is adopted to solve a current differential equation, and inverse transformation is carried out after integration to obtain stator current; and outputting an electromechanical state quantity in combination with the torque and the motion equation. The whole link of the FPGA adopts fixed-point number calculation, and the nanosecond-level simulation step length is realized by unifying the data scale through parameter pre-scaling and numerical value per unit. And when the third harmonic voltage component is zero, the model is degraded into a standard five-phase motor system, and adaptive compatibility of a harmonic injection mode and a standard driving mode is realized. Compared with the prior art, fine real-time simulation of the five-phase motor system considering the third harmonic is realized, and the real-time verification requirement of a high-dynamic scene can be met.
Owner:MODELINGTECH ENERGY TECHNOLOGY CO LTD

Hybrid micro-grid control method based on MPC

The invention discloses a hybrid micro-grid control method based on MPC, and belongs to the technical field of power grid control, and the method comprises the steps: S1, building a state-space equation of a hybrid micro-grid based on a variable quantity representing the stability of the hybrid micro-grid and an influence variable influencing the stability of the hybrid micro-grid; s2, acquiring an output equation based on the variable quantity, and discretizing the state-space equation and the output equation based on a forward Euler method to acquire a prediction equation; and S3, constructing a performance index function of the MPC according to the prediction equation, solving the performance index function by taking the minimum value of the performance index function as a control optimization target to obtain a final value of a control variable, and controlling the hybrid microgrid based on the final value of the control variable. The problems of insufficient direct-current voltage support, dynamic coupling oscillation and steady-state power distribution imbalance are synchronously solved by considering the stability of both sides of alternating current and direct current, so that the technical problem that the stability of the hybrid microgrid is difficult to comprehensively improve in the prior art is solved.
Owner:STATE GRID ZHEJIANG ELECTRIC POWER CO LTD YUHUAN CITY POWER SUPPLY CO

A cascaded large model robot motion planning method based on timing logic constraints

The application discloses a cascaded large model robot motion planning method based on timing logic constraints, which comprises the following steps: a task planner receives user instructions and corresponding STL expressions, environment information, decomposes the user instructions and corresponding STL expressions, and obtains sub-tasks and corresponding STL expressions; whether the decomposed sub-tasks meet the logic constraints, time constraints and space constraints is detected by an STL checker; if yes, correct controllers are generated according to the sub-tasks; the generated correct controllers are integrated with a robot model, a Monte Carlo method is used to generate multiple groups of random parameters based on uncertainty factors, real environment disturbances are simulated, an Euler method is used to discretize and iteratively solve trajectories of the robot continuous kinematics equation, the trajectories are checked by the STL checker to make the trajectories meet the requirements of the user instructions, and finally correct trajectories are obtained. The application realizes user instructions containing space, time and kinematics constraints.
Owner:SHANGHAI UNIV

Robot joint self-adaptive control method and system containing input saturation constraint

The invention relates to the technical field of automation, in particular to a robot joint self-adaptive control method and system containing input saturation constraint. The method is based on a Newton-Euler method, nonlinear factors such as friction, gaps and time-varying stiffness and input saturation constraints are considered, and a two-mass kinetic equation of the micro driving system is established. And designing a disturbance observer based on a kinetic equation to estimate non-matching disturbance existing in the system, designing a state observer considering input saturation according to a state space equation and a disturbance estimation value, and observing all state variables of the system. And designing a neural network adaptive backstepping control algorithm considering input saturation according to the state observation value and the disturbance estimation value. Meanwhile, according to the Lyapunov stability theory, whether the system is consistent and stable in a semi-global mode or not is judged, and the control performance of the IT2-FCMAS-DSCABM control algorithm is verified by means of Matlab software.
Owner:CHANGSHA UNIVERSITY OF SCIENCE AND TECHNOLOGY

Permanent magnet synchronous motor weight adaptive prediction position control method based on Lyapunov stability

The invention discloses a permanent magnet synchronous motor weight adaptive prediction position control method based on Lyapunov stability, and the method comprises the following steps: 1, carrying out the discretization of a motion equation and a voltage equation through employing a forward Euler method, building a discrete state space model through employing feedback linearization, deducing an incremental state space model, and carrying out the calculation of an incremental state space model; a multi-step prediction output Y is obtained through iterative calculation; 2, constructing a value function Js according to multi-step prediction output; step 3, constructing a Lyapunov function V (k), iteratively updating a d-axis current weight wid and a position weight w theta of a tracking error weight matrix Qa in the value function Js obtained in the step 2 to ensure that a forward variation delta V of the Lyapunov function is less than or equal to 0, dynamically adjusting the weight matrix Qa in the value function Js, and solving an optimal control increment delta U'by minimizing Js; and 4, judging whether the voltage and the current in the optimal control increment delta U'exceed the limit or not under the constraint condition, if so, directly constraining and limiting the current and the voltage in the optimal control increment sequence delta U, and otherwise, directly outputting the current and the voltage.
Owner:TIANJIN UNIV OF TECH & EDUCATION (TEACHER DEV CENT OF CHINA VOCATIONAL TRAINING & GUIDANCE)

Method for constructing load dynamic response model of pile type fence structure

The invention belongs to the field of ocean devices, and provides a pile type fence structure load dynamic response model construction method, which comprises the following steps: obtaining engineering arrangement parameters of a fence structure, constructing a wave flow field near the fence structure based on a potential flow theory, and calculating the speed and acceleration of a water quality point; piles and connecting components are regarded as rigid structures, a rigid body dynamic motion equation is established, a netting system is regarded as a flexible structure, and a dynamic model of the netting system is established through a concentrated mass point method; hydrodynamic loads of the piles, the netting and the connecting components are calculated, and effective tension of the slender rod components is calculated; calculating the horizontal bearing capacity of the pile foundation to simulate pile-soil interaction; and finally, carrying out numerical solution on the kinetic equation by adopting a semi-implicit Euler method to obtain dynamic response results of pile bending moment, netting tension and node displacement. The multi-system coupling dynamic response characteristic of the pile type fence structure under the wave action can be comprehensively reflected, and the method is suitable for safety evaluation and engineering design of the fence structure.
Owner:ZHEJIANG OCEAN UNIV

Electro-hydraulic servo system model prediction control method, equipment and medium

The invention discloses an electro-hydraulic servo system model prediction control method and device and a medium, and relates to the technical field of electro-hydraulic servo model prediction.The electro-hydraulic servo system model prediction control method comprises the steps that data collection is conducted based on an electro-hydraulic servo system, a state variable vector is defined according to resultant force formed by equivalent cavity pressure differences, discretization processing is conducted through a forward Euler method, and the state variable vector is obtained; a piston stress balance equation is constructed, state variable vector data are updated, a relation equation of the opening degree of the valve element in the electric control domain and control voltage is set, the flow of the hydraulic cylinder flowing into the upper cavity and the lower cavity is updated, and state variable vectors are reconstructed and updated. According to the method, through combined use of a stress balance equation of a mechanical domain and an electric control domain compensation signal, voltage change sent by a controller can be equivalent to direct control over output force, and through integrated fusion of a static mapping function and a dynamic compensation function, the output force can be compensated. The compensated voltage driving signal can maintain ideal linearity in a steady state, and can correct a lag error in real time in a dynamic change.
Owner:NANJING TOMORROW INTELLIGENT CONTROL TECH CO LTD

Magnetic source parameter inversion method and system based on mixed direction oblique derivative Euler method

The invention provides a magnetic source parameter inversion method and system based on a mixed direction oblique derivative Euler method, and belongs to the field of magnetic exploration. The aeromagnetic data is subjected to inversion calculation through a pre-constructed mixed direction tilt-Euler equation set, an initial Euler solution is obtained, and the mixed direction tilt-Euler equation set is determined in combination with mixed direction tilt gradient derivative transformation after three-dimensional Euler deconvolution equation vertical integration and second-order mixed partial derivative processing; screening the initial Euler solutions based on a mixed direction tilt gradient total horizontal derivative corresponding to the mixed direction tilt gradient derivative to determine an inversion solution; and performing direction combination on the inversion solution to obtain a magnetic source parameter prediction result of the to-be-explored area. According to the method, the credibility and the aggregation degree of a magnetic source parameter solution are remarkably improved, and the practicability and the reliability of Euler deconvolution in a complex magnetic anomaly environment are greatly improved.
Owner:EAST CHINA UNIV OF TECH

Euler method water drop collection coefficient effective area determination method

The invention relates to an Euler method water drop collection coefficient effective area determination method comprising the following steps: modeling and dividing grids according to the geometric shape of an aircraft; a fluid mechanics model is selected, and a steady-state air flow field is obtained through calculation; establishing and solving an Euler method water drop motion control equation, and calculating water drop collection coefficient distribution according to the wall surface water drop volume fraction and the velocity vector; obtaining a water drop streamline and calculating water drop collection coefficient distribution according to streamline parameters; comparing the results of the water drop collection coefficients to obtain a preliminary effective region of the Euler method water drop collection coefficients; and recalculating the initial effective area by using a Lagrange method, and judging to obtain an Euler method water drop collection coefficient effective area. According to the method, the effective region of the Euler method water drop collection coefficient can be judged, and on the basis of the method, the water drop collection coefficient of the effective region adopts a calculation result of the Euler method, and only an invalid region needs to be independently calculated by using a Lagrange particle statistical method; compared with a Lagrangian particle statistical method, global calculation is faster.
Owner:BEIHANG UNIV

A design method, device, equipment and medium of a supersonic convergent-divergent nozzle

The application belongs to the technical field of nozzle design, and relates to a design method, device, equipment and medium of a supersonic point convergence nozzle. The method comprises the following steps: obtaining design parameters of the supersonic point convergence nozzle, obtaining a point convergence flow control equation, a characteristic line equation of supersonic flow and a compatibility equation, and obtaining a left-running characteristic line at a nozzle outlet and a right-running characteristic line at a nozzle throat by using an improved Euler method; taking the left-running characteristic line at the nozzle outlet, the right-running characteristic line at the nozzle throat and a symmetry axis of the nozzle as boundary conditions, and obtaining a point convergence nozzle flow field by using a characteristic line method; obtaining a supersonic surface of the supersonic point convergence nozzle by using a mass conservation formula along the right-running characteristic line at the nozzle throat in the obtained point convergence nozzle flow field; designing a converging section of the supersonic point convergence nozzle, connecting the converging section with the supersonic surface of the supersonic point convergence nozzle, and then correcting to obtain a supersonic viscous point convergence nozzle. The application can provide supersonic point convergence flow.
Owner:NAT UNIV OF DEFENSE TECH