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66 results about "Eulerian method" patented technology

Therefore, Eulerian method is suitable for simulation of large deformation and fluid movement (Dorosevas 2007). Eulerian method typically used in simulating fluid, in which the material flows through a stationary domain represented by grids).

SOGI-QNPLL-based permanent magnet synchronous motor non-inductive vector control method

The invention discloses a permanent magnet synchronous motor non-inductive vector control method based on SOGI-QNPLL. The method comprises the following steps: constructing a current state equation of a permanent magnet synchronous motor under a two-phase static coordinate system; constructing a new switching function, and designing and improving a full-order sliding mode observer according to the new switching function and the current state equation; the convergence of the improved full-order sliding mode observer is analyzed, and the value ranges of the gain m and the gain n of the improved full-order sliding mode observer are calculated; analyzing the improved full-order sliding-mode observer, and discretizing the improved full-order sliding-mode observer by adopting a forward Euler method; establishing a phase-locked loop (PLL), performing normalization design on the phase-locked loop, and establishing a normalized phase-locked loop (QNPLL); a second-order generalized integrator (SOGI) is established and discretized by adopting a bilinear transformation method, the discrete SOGI is combined with the QNPLL to form SOGI-QNPLL, and the SOGI-QNPLL is utilized to estimate the rotor position. According to the SOGI-QNPLL provided by the invention, the rotor position can be accurately extracted, the observation precision is remarkably improved, and the reliability and performance of the system are enhanced.
Owner:JILIN UNIVERSITY

Tranform-based modeling method for mechanism hybrid prediction model of SCR (Selective Catalytic Reduction) denitration system

The invention discloses a modeling method of an SCR (Selective Catalytic Reduction) denitration system mechanism hybrid prediction model based on Transform. Feature extraction is carried out on the collected data, a reaction kinetic equation is constructed, an Euler method is adopted for solving, and unknown model parameters are reserved; a section of working condition stable data is selected from the collected data and imported into a mechanism model, optimal model parameters are found, the mechanism model of the SCR denitration reaction is obtained, and the A side outlet flue concentration and the B side outlet flue concentration are calculated through the model; a Transform model is trained to compensate the SCR system mechanism model, and the compensated SCR system mechanism model serves as real-time soft measurement values output by the A side and the B side; input variable selection is carried out on all-condition data, A-side and B-side outlet flue concentrations obtained by the mechanism model in real time and outputs at the first two moments are included into an input variable set, and time delay processing is carried out on input variables; and the mechanism models of the A-side flue and the B-side flue are connected in series with a Transform model, the Transform model needs to be imported into the output of the mechanism models in real time, and finally the SCR denitration system hybrid prediction model is obtained.
Owner:SOUTH CHINA UNIV OF TECH

Quadrotor unmanned aerial vehicle attitude estimation method and device based on improved UKF, and medium

The invention discloses a quadrotor unmanned aerial vehicle attitude estimation method and device based on an improved UKF and a medium, and the method comprises the steps: constructing a kinetic model of a quadrotor unmanned aerial vehicle, deducing an attitude angle kinetic equation through a Newton-Euler method, and superposing a wind shear model and a turbulent wind field model; the method comprises the following steps: collecting multi-source sensor data, and performing hierarchical filtering processing on the multi-source sensor data through a multi-source data fusion and dynamic noise suppression technology; and performing attitude estimation on the quad-rotor unmanned aerial vehicle by adopting a UKF (Unscented Kalman Filter) algorithm of an improved adaptive factor based on the deduced and superposed kinetic model and the processed multi-source sensor data. Through the above method, the method is closer to a real flight environment, the influence of environment sudden change on data quality is inhibited, and high-precision and high-stability attitude estimation is realized.
Owner:INSPUR SMART TECH INNOVATION (SHANDONG) CO LTD

Model-free predictive control harmonic and torque ripple suppression method for permanent magnet synchronous motor

The invention discloses a model-free predictive control harmonic and torque ripple suppression method for a permanent magnet synchronous motor. The method comprises the following steps: sampling physical information of the permanent magnet synchronous motor; performing Clarke transformation on the obtained three-phase current, and performing Park transformation by applying the sampled rotor position to obtain actual current under the dq axis; according to the obtained dq-axis actual current and the motor winding voltage, updating an ESO-based hyper-local model after forward Euler method discrete transformation; calculating a control voltage by applying a traditional dead-beat current control method through a disturbance update value obtained through calculation; and carrying out inverse Park conversion on the deadbeat control voltage obtained after calculation, then carrying out traditional SVPWM modulation to obtain a three-phase PWM waveform, and inputting the three-phase PWM waveform into a driver to control the permanent magnet synchronous motor. According to the method, current ripples and torque ripples of model-free predictive control of the permanent magnet synchronous motor can be remarkably reduced, high-frequency harmonics in the operation process of the motor can be remarkably reduced, and the calculation burden is reduced.
Owner:ZHEJIANG UNIV

Alternating current optimal transmission switching relaxation problem solving method based on two-stage dynamic trajectory and pseudo-transient continuity

The invention discloses an alternating current optimal transmission switching relaxation problem solving method based on a two-stage dynamic trajectory and pseudo-transient continuity. The method comprises the following steps: constructing an alternating current optimal transmission switching relaxation model; constructing an augmented quotient gradient system corresponding to the alternating current optimal transmission switching relaxation model; randomly selecting an initial point x0, and performing integral augmentation on the quotient gradient system from x0; carrying out integral iterative calculation on the augmented quotient gradient system by adopting a pseudo-transient continuous iterative formula based on an Euclidean Euler method; when the target function descent rate of the trajectory of the augmented quotient gradient system is smaller than 0.001% / step, integration is stopped, and the termination point at the moment is recorded as x *; x * is used as an input point, an IPOPT solver is adopted to solve the alternating current optimal transmission switching model, and an optimal solution is obtained through solving. According to the method, a dynamic method and a static method are combined, respective advantages of the two methods are taken, a pseudo-transient continuous iteration formula is provided in the integration process of the augmented quotient gradient system, and the optimal transmission switching relaxation problem which is difficult to solve by the power system can be quickly solved on the basis of ensuring the solution robustness.
Owner:NANJING NORMAL UNIVERSITY

Water drop shielding area and water drop concentration enhancement area simulation method based on Lagrangian method

The invention relates to a method for simulating a water drop shielding area and a water drop concentration enhancement area based on a Lagrange method. The method comprises the following steps of: carrying out geometric modeling and grid division on a simulated aircraft part; solving an air flow field according to working conditions; establishing a water drop stress motion equation under a Lagrange framework; water drops are released from a far field at fixed intervals in the direction perpendicular to the incoming flow speed of the airflow; solving the stress motion equation of each water drop on the air flow field, and recording the water drop collection quantity of the space grid; solving motion tracks of all released water drops, traversing all space grids, and calculating a space water drop collection coefficient of each space grid; and distinguishing a water drop shielding area and a water drop concentration enhancing area according to the spatial water drop collection coefficient. The Lagrangian method can accurately track the water drop movement process, the problem that the Euler method cannot accurately simulate the convergence or intersection phenomenon after water drop deflection is solved, and meanwhile, the water drop characteristic space field distribution rule is obtained from the water drop movement track through the definition solution of the space water collection coefficient.
Owner:BEIHANG UNIV

Humanoid robot arm end mechanism path real-time planning method

According to the real-time path planning method for the arm end mechanism of the humanoid robot, all joints of the mechanical arm of the humanoid robot can be controlled to rotate through path planning, and therefore the purpose that the end executing mechanism of the humanoid robot reaches the designated position is accurately achieved. According to the algorithm, a target point which a robot end execution mechanism needs to reach, an iteration stopping distance and a stopping number in iteration are determined according to engineering requirements, the L2 norm of a target position posture and a current position posture error is minimized through a Newton-Euler method, and the optimal position at the next moment and the corresponding iteration joint angle are solved. And through repeated iterative calculation, the tail-section executing mechanism of the mechanical arm can reach the target point accurately finally. The target passes mathematical simulation verification, and finally, when the tail end of the mechanical arm reaches the target point through planning, the position error reaches the order of magnitude of 1e-10m, and the high-precision planning effect is displayed. The algorithm planning precision is high, and the method has a good application prospect.
Owner:BEIJING AEROSPACE AUTOMATIC CONTROL RES INST

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

Dynamic model error compensation method based on SSA-LSTM neural network model

The invention discloses a dynamical model error compensation method based on an SSA-LSTM neural network model, and relates to the technical field of robots, and the method comprises the steps: building a pre-uncompensated dynamical model of a robot through employing a Newton-Euler method or a Lagrange method according to a robot structure, and obtaining a predicted output torque under a minimum inertia parameter set; and calculating an uncompensated predicted torque for the original displacement, speed and acceleration data by using the uncompensated kinetic model. According to the method, through physical prior and sequence residual learning, the output of the physical dynamics model is used as a part of network input, data requirements are reduced, maintenance of interpretable physical components is improved, meanwhile, the problem of compensation of non-analytic items is solved, convergence is accelerated, generalization and physical consistency are improved, and the method is suitable for large-scale popularization and application. Under the condition of limited test data, lower residual errors and more stable online compensation performance can still be obtained, and control robustness is enhanced.
Owner:SHANGHAI BAOSIGHT SOFTWARE CO LTD +1

A trajectory tracking control method for unmanned ship predicted by a preset performance convex line model

The present invention discloses a method for predicting the trajectory tracking control of an unmanned ship using a preset performance convex online model, which belongs to the field of trajectory tracking technology and is used for unmanned ship trajectory tracking control, including modeling an unmanned ship, discretizing a continuous time-varying nonlinear model using the preceding Euler method, using a linear time-varying model predictive control method to process nonlinear state space equations; optimizing the objective function, converting the predictive control into quadratic programming, establishing the constraints required for the predictive control, establishing a preset performance function discrete at a specified time through predefined time control, thereby rewriting the constraints; solving the objective function, and obtaining the latest position under the trajectory of the unmanned ship. The present invention discretizes the continuous nonlinear model through the preceding Euler method to reduce the complexity of the calculation, and uses the predefined time control method to construct a preset performance function discrete at a specified time, so as to meet the accuracy requirements of trajectory tracking under the preset performance of the specified time of the tracking error.
Owner:SHANDONG UNIV OF SCI & TECH

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

A collaborative robot dynamic error modeling and compensation method

The application relates to a collaborative robot dynamic error modeling and compensation method, which comprises the following steps: step one: a kinematics model of the collaborative robot is established by using an M-DH method; step two: a dynamics model of the collaborative robot is established based on a Newton-Euler method by considering the influence of robot self-weight, inertial force and load on joint torque, so that joint driving torque during robot operation is obtained; step three: a collaborative robot end dynamic error model is established according to the relationship between dynamic force and joint torsional stiffness, and the influence of supplementary stiffness on the end dynamic error is considered; and step four: the end dynamic error is converted to the joint space, and dynamic error compensation is carried out on the collaborative robot. The application establishes a collaborative robot dynamics model considering factors such as gravity, inertial force and end load, and further establishes an end dynamic error model considering supplementary stiffness, so that the end dynamic error compensation problem under the action of dynamic force is solved.
Owner:SHENYANG INST OF AUTOMATION - CHINESE ACAD OF SCI

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

Multi-vector model predictive control method based on incremental global optimization

The invention discloses a multi-vector model prediction control method based on incremental global optimization, and the method achieves the control of a permanent magnet synchronous motor through the following steps: carrying out the discretization of a current state equation through employing an Euler method, and obtaining a current prediction model; a virtual vector with a harmonic plane component being zero is adopted as a vector control set, and a value function is set as the difference sum of squares of the predicted current and the reference current; subtracting the prediction current equations of two adjacent periods to obtain an incremental current prediction equation, and enabling the prediction current to be equal to the reference current to obtain an incremental voltage prediction model without a flux linkage item; selecting a synthetic reference vector according to the vector set; carrying out duty ratio distribution on the selected voltage vector scheme; and updating the value function and obtaining a global optimization vector scheme after duty ratio distribution. The method improves the robustness of the system, reduces the calculation amount, improves the prediction precision of the system, can be popularized to the motor control of an N * 3 phase structure, and is wide in application range.
Owner:NANJING UNIV OF AERONAUTICS & ASTRONAUTICS

A general reconfigurable simulation system for power electronic converters

The application discloses a general reconfigurable simulation system of a power electronic converter, comprising: a dynamic element module, which is used for solving a dynamic element state equation according to a forward Euler method to obtain a dynamic element state variable, and sending the dynamic element state variable to a switch module according to a preset selection instruction; the switch module is used for constructing a general matrix model for a bridge arm switch of the converter, processing the dynamic element state variable through the general matrix model, and generating a switch voltage and a switch state instruction; a neutral point voltage solving module, which is used for constructing a neutral point voltage model for a three-phase rectification or inversion circuit according to the switch voltage and the switch state instruction, and solving to obtain a neutral point voltage; and a power supply module, which is used for providing different power supply voltages for the neutral point voltage solving module, wherein the power supply voltages include three-phase alternating voltages and a direct current voltage. The technical problems that the simulation adjustment flexibility is poor in different scenes, the modeling is complicated due to the increase of system element complexity, and the simulation compilation is time-consuming in the prior art are solved.
Owner:ELECTRIC POWER RES INST CHINA SOUTHERN POWER GRID CO LTD +1

A method for simulating equivalent signals for gyroscope testing based on Euler discrete model

ActiveCN115979300BGyroscopeDifferentiator
This invention provides a simulation method for test equivalent signals based on the Euler discrete model. It primarily solves the problem of equivalent generation of gyroscope angle signals in test equivalent converters, enabling high-precision reproduction of the complex dynamic angle changes of an aircraft during flight. This overcomes the difficulty of accurately simulating gyroscope angle signals during ground testing. First, using predetermined aircraft pitch channel altitude trajectory data, a fast differentiator is used to solve for the differential data of the altitude and horizontal trajectories, thereby solving for the aircraft pitch angle and pitch velocity data. Then, the Euler method is used to establish a discrete measurement model of the gyroscope, solving for the measured value of the pitch velocity. Considering the influence of error drift, integration is performed to obtain the gyroscope's measurement signal of the pitch angle. This outputs a high-precision result of the gyroscope angle changes during high-altitude flight. This method has the advantages of high simulation accuracy and good agreement with reality.
Owner:NAVAL UNIV OF ENG PLA

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

Nine-switch converter flexible interconnection system and switch loss control method and device thereof

ActiveCN122092696BPower qualityVoltage vector
The application discloses a nine-switch converter flexible interconnection system and a switching loss control method and device thereof. αβ The method comprises the following steps: firstly, 27 voltage space vectors are obtained by constructing a nine-switch converter mathematical model; secondly, a system Coordinate system mathematical model is established, a prediction model is obtained through forward Euler method discretization processing, and a weight coefficient value function is designed to accurately track the current; then, voltage vectors are selected and inserted into zero vectors, and a fixed switching frequency switching sequence is designed; finally, the action time of the voltage vector is determined through duty cycle modulation, and the optimal voltage vector is periodically and alternately selected. The application effectively solves the problems of the existing system, such as unfixed switching frequency, uneven loss, large current harmonic and heavy calculation burden, balances the power device loss, prolongs the service life of the device and improves the system stability. The application can realize the bidirectional power flexible interconnection between two three-phase power grids and guarantee the system operation stability and power quality.
Owner:CHINA UNIV OF MINING & TECH

Method for determining installation position of probe type icing detector

The invention provides a method for determining the installation position of a probe type icing detector. The method comprises the following steps: modeling a pre-installation part of an aircraft icing detector; performing grid division on a computational domain of the model to generate a grid meeting simulation requirements; solving air flow field information in the grids according to set working conditions; performing water drop movement and wall impact characteristic calculation by using an Euler method to obtain spatial water drop collection coefficient distribution; and reading spatial water drop collection coefficient distribution, and judging a water drop shielding area and a water drop concentration enhancement area according to judgment conditions. The installation position of the detector is designed and determined according to the requirement that the installation position of the icing detector ensures that the detector probe extends out of the water drop shielding area and the water drop concentration enhancing area. The method solves the problem that the distribution rule of the impact amount between the water drop shielding area and the probe water drop cannot be accurately described only by means of the ratio of the local liquid water content to the far-field liquid water content.
Owner:BEIHANG UNIV

Linearized Modeling Method for Real-Time Simulation of Power Electronic Converters

The present invention discloses a general linearized electromagnetic transient modeling method for power electronic converters. Due to the nonlinearity of power electronic converters, the system nodal admittance matrix changes with the switching state, and the time-varying nodal admittance matrix limits the scale of new power system simulations. The present invention proposes a general linearized modeling method for power electronic converters based on constant admittance of port characteristics, without introducing virtual inductors and capacitors to equivalent switches. By establishing a state space equation for the port characteristics of the converter and combining it with the internal switching state, a constant admittance adjoint circuit model of the power electronic converter is derived based on the improved Euler method. This model supports both switch unlocking and locking modes without switching equivalent circuits. In addition, the proposed method can eliminate the delay between the converter model and the global solution of the system, thereby effectively improving the accuracy of multi-power electronic converter simulations.
Owner:SOUTHEAST UNIV

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

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

Transverse control method for self-driving automobile with self-adaptive time domain parameters at different automobile speeds

The invention discloses a transverse control method for an automatic driving automobile with self-adaptive time domain parameters at different automobile speeds, and belongs to the technical field of transverse control of the automatic driving automobile. Constructing a nonlinear state equation based on the transverse dynamic model; performing first-order Taylor expansion on the starting point of the nonlinear state equation to construct a linear state space expression; performing discretization processing on the linear state space expression by using a forward Euler method to obtain a discretization model, and constructing a target function; optimizing the objective function by introducing a relaxation factor; obtaining a quadratic programming problem through the discretization model and the optimized target function, and setting the constraint of the quadratic programming problem; and a time domain parameter adaptive controller is constructed, and an optimal control time domain and an optimal prediction time domain are obtained by using a multivariable control strategy. According to the invention, the accuracy of the self-driving automobile at a low speed is ensured, the stability at a high speed is also improved, and the driving safety of the automobile at different speeds is ensured.
Owner:CHONGQING UNIV OF TECH

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