14 results about "Euler method" patented technology

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.