211 results about "Particle model" patented technology

The invention relates to a soft tissue deformation simulation method based on smooth particle hydrodynamics, belonging to the technical field of graphic processing. In the method, a smooth particle hydrodynamics method is selected, and a viscoelastic mechanics model is used for reflecting the biomechanical characteristics of soft tissue. The method comprises the following steps of: constructing a series of equations related to soft tissue deformation simulation according to the viscoelastic model; selecting a proper support domain search strategy and a smooth kernel function, approximately calculating each related item of the equation by adopting the particle approximation method, and calculating the variation values of the density, the position, the velocity and the like of each particle along with time through the display integration method; and dynamically outputting the status of each time step size of the particle model to a screen, rendering texture irradiation, and displaying the real-time deformation process of soft tissues and organs under stressing conditions. The method does not need troublesome grid computing, thereby increasing the accuracy and the real-time performance of soft tissue deformation simulation.

The invention discloses a long-life rapid charging method for a lithium ion battery, and relates to the field of research of new energies. The invention is to solve the problem that the traditional lithium ion battery is low in charging efficiency and large in damage to the battery during a charging process. According to the method, an improved single-particle model is established for the lithium ion battery; the mechanism parameters of the battery in the improved single-particle model is obtained by using an excitation response analysis method; according to the mechanism parameters of the battery, the embedded lithium rate on the active substance surfaces of the anode of the battery is obtained; the size relationship between the embedded lithium rate on the active substance surfaces of the anode and a set threshold is obtained by comparison, and the charging current size and charging time of the battery are controlled according to the size relationship, and thereby the rapid charging of the lithium ion battery is achieved. The method is applied to the long-life rapid charging of the lithium ion battery.

The invention belongs to the technical field of a lithium ion power battery of an electric vehicle, relates to a mechanism modeling method for the lithium ion battery and overcomes the defects that the electrochemical model of the lithium ion battery is complex in structure, parameters are difficult to identify and the experimental model precision is low. The mechanism modeling method comprises the following steps of: (1) building a single-particle model of the lithium ion battery; (2) simplifying a solid-phase diffusion equation in the single-particle model of the lithium ion battery by adopting a three-parameter parabola method; (3) identifying unknown parameters in the single-particle model of the lithium ion battery by adopting a bacteria foraging optimization algorithm; and (4) fitting an anode open-circuit voltage expression of the single-particle model of the lithium ion battery. According to the invention, by adopting the three-parameter parabola method, the structure of the single-particle model of the lithium ion battery is simplified; the unknown parameters in the single-particle model of the lithium ion battery are identified by adopting the bacteria foraging optimization algorithm, the identification speed is high, and the globally optimal solution is obtained; and the mechanism modeling method provides theoretical support for the state estimation, life prediction and characteristic analysis of the lithium ion battery.

The invention discloses a near-distance air combat automatic decision-making method based on single-step prediction matrix gaming. The method comprises the following steps: step 1, erecting a six-degree-of-freedom nonlinear unmanned combat air vehicle control law structure; step 2, initializing a matrix gaming chessboard; step 3, according to the gaming chessboard, carrying out single-step prediction calculation; step 4, calculating a payment function matrix; step 5, carrying out strategy selection through a minimax algorithm; step 6, updating a six-degree-of-freedom plane kinetic and dynamic equation; and step 7, determining whether an air combat termination condition is reached. The method has the following advantages: compared to a three-degree-of-freedom particle model, the actual application value is higher. At the same time, a conventional matrix gaming method based on a maneuver library is changed to be based on a maneuver library of an instruction model, what is needed is only prediction of a step length of a single step, the decision-making time is effectively reduced, the requirement for real-time performance of air verification is satisfied, the method can be better adapted to complex dynamic baffle field environment change, and the combat capability of an unmanned combat air vehicle in a near-distance combat is improved.

The invention relates to the field of high-performance computer value simulation technology and discloses a particle model-oriented multi-layer direct-connecting cluster parallel computer system. The system comprises a plurality of nodes; the nodes are arranged into one-dimensional or multi-dimensional array of a layer or multiple layers in logic; communication connection can be directly carried out between the adjacent nodes on the same layer, thus realizing the high-speed data transmission between the adjacent nodes on the same layer and the communication connection between nodes on different layers through an exchanger. The invention simplifies the design of the high-performance computer system, increases the calculation rate of the high-performance computer system on the particle method and similar calculations, and avoids the conflict between the communication and the memory access, thus fully overlapping the calculation and the communication operation of the nodes, allowing the calculation to gradually advance towards the sequential time from the peripheral area corresponding to the nodes to the center and further effectively relieving the small-scaled load fluctuation.

The invention discloses a method for generating a control assistance decision instruction based on required time of arrival (RTA). The method comprises the following steps of: constructing an aircraft initial intention model, an external environment model and a particle model required by four-dimensional flight path prediction; and performing flight path prediction on an aircraft to obtain an initial four-dimensional flight path and the estimated time of arrival of a waypoint; obtaining the RTA of the waypoint by using a flight ordering and conflict release function in a control automation system or a control auxiliary decision system; optimizing the initial four-dimensional flight path of the aircraft; displaying the predicted horizontal trajectory and the vertical profile of the aircraft in an air traffic control assistance system and directly generating a control instruction that should be issued by a controller to a pilot. The method quickly generates the control instruction through the flight path prediction and flight path optimization. The instruction and the flight path planned by the method are easy to operate and good in controllability to the pilot, and can enable the aircraft to pass the waypoint according to the required arrival time.

The invention discloses a particle flow simulation system and method on the basis of GPUs. The method includes: generating particle information according to particle modeling information input by a client, and generating geometry information; receiving the particle information and the geometry information, determining that which GPUs in which computational nodes are used according to the number of particles and the number of idle GPUs in the computational nodes, determining that which particles are calculated by which GPUs in which computational nodes according to the determined number of the GPUs and distribution condition of the particles in space, and performing distribution according to determined results; calculating stress of each particle caused by impact of the particles in a plurality of GPUs in a parallel mode, and working out accelerated speed further so as to simulate particle flow; showing simulation results. According to the particle flow simulation system and method, high-density particle virtual experiment simulation can be achieved, energy consumption is reduced, and meanwhile calculation efficiency is improved.

The invention relates to a three-dimensional visualized algorithm for maritime oil spill, which is realized in a way that: on the basis of drawing a large-scale sea level scene, dividing an oil spill process within a short time scale into an oil film self-spreading stage and an oil film drift diffusion stage, and calculating the oil spill loci of the two stages respectively by selecting an Lehr model and an oil particle model; simulating the oil particle model by using a particle system; and visualizing the oil spill loci on the simulated sea level by utilizing a planar refraction technology, accessing the veins in a fragment shader of a GPU by projecting vein coordinates, and simulating and reproducing the three-dimensional scene of maritime oil spill while drawing the sea level refraction effect. The algorithm solves the problems of simulation of the oil particle model, visualization of the oil spill loci on the simulated sea level, and the like, and realizes the vivid and visual simulation of the three-dimensional movement change process of oil spill within a short time scale.

The invention relates to the field of high-performance computer numerical simulation technologies and discloses a design project facing the nodes in a multi-layer directly-connected cluster parallel computing system, which consists of a plurality of logic circuit units having independent operation, storage and communication functions. The logic circuit unit at least has a logic circuit unit being a communication unit capable of directly communicating with other nodes. The other logic circuit units are computing units that execute computation task. Every computing unit is at least in direct communication with the communication unit. The units are different in function and the combination thereof makes the constitution of the node more abundant, flexible and more reliable between nodes and can improve the computing efficiency of node such that the multilayer directly-connected cluster parallel system can much more effectively execute particle simulation.

The invention relates to a modeling method of a dispersed-phase reinforced composite material meso-structure. The modeling method comprises the following steps that the shape and the size of a model of a composite material are prepared, and the boundary of the model is determined; the sum of the volumes of particle reinforced phases in different size ranges in the model is prepared; particle models in all the size ranges are generated; the surface of each particle model is divided into finite element grids, and the prepared boundary of the model is divided into finite element grids; shell element attributes are given to the finite element grids; the mode of contact between the particle models and the mode of contact between the particle models and the boundary of the model are defined, and the descending process of particles in the space is simulated through a finite element method; the internal space of the model can be exactly filled with the particle models in all the size ranges; finite element models of the particle models and a finite element model of a substrate are obtained; modeling of the particle reinforced composite material structure is accomplished through the definition of the mode of constraint between the substrate and the particles and the material attributes of the substrate and the particles.

An abrasive particle morphology database creation method based on a conditional generative adversarial network comprises: deeply mapping three-dimensional abrasive particle images to form two-dimensional images, and the two-dimensional images serving as output target images in a training sample; constructing an abrasive particle model according to the real abrasive particle image, which mainly comprises an abrasive particle contour, abrasive particle color filling and surface texture representation symbols, and taking the constructed abrasive particle model as an input image of a CGAN training sample; inputting the paired input images and the target image as samples of the CGAN into a network for training, and generating a generator for expanding the samples by the CGAN; and finally, carrying out network testing by using the input image as an input, counting an error between the generated image and the target image by using a discriminator, and finally judging whether the image is the target image or the generated image. According to the method, the effectiveness of loss function evaluation is improved, the accuracy of the network output image is also improved, and the similarity between the network output image and the real image is very high.

The invention discloses a coagulation phenomenon simulation method based on a particle model. The method includes the steps that 1, discrete modeling is conducted on the phenomenon that gas coagulates on the solid surface, wherein the influence of the dew point temperature and the relative humidity property in a humidity diffusion model on the details of the coagulation phenomenon is considered; 2, a soil-liquid coupled boundary density correction algorithm is proposed, the problem of particle loss of a smoothed-particle hydrodynamics model at the boundary is solved, and meanwhile particle penetration is prevented under the condition that the time step is not decreased; 3, a particle system is used for conducting discrete modeling on air, the simulation process can be expressed more visually, and adjustment and design can be conducted easily. By applying the method, the flow property, heat conduction property and the like of air can be conveniently adjusted, and the problems that existing air heat exchange phenomenon simulation is not visual in effect and lacks enough details are solved; the method has certain practical value.

The invention discloses a modeling method for a high-compactness discrete particle heterogeneous system. The method comprises the following steps that: determining a model boundary; drawing up the volume sum of particle phases in each dimension range in the model; generating the compression models of the particle models in all dimension ranges; carrying out expansion on each particle in the compression model; and obtaining a high-compactness particle accumulation model. The method can be used for enhancing the modeling of microstructures including particle reinforced composite materials, soft substance particle materials, particle accumulation materials and the like, and can be expanded and applied to short fiber enhanced composite materials. By use of the method, a modeling problem generated when particles and the model boundary are cross is solved, and the modeling method can be applied to the modeling and the analysis of a composite material specimen of which the edge is subjected to machining.

The invention discloses a numerical analysis method for the piping phenomenon. The method comprises the steps of obtaining a seepage deformation similarity criterion on the basis of a fluid dynamics similarity criterion combined with alternate force acting item of medium on fluid; building a microscopic particle model on the basis of the seepage deformation similarity criterion combined with a particle flow method, wherein the model is consistent with a prototype in gravity horizontality; generating skeleton and filling particles under the conditions of zooming particle size distribution and maintaining the same porosity; conducting piping process simulation on the model, and outputting parameter information inside the model when the filling particles in the model reach the balance state or the skeleton particles are damaged; obtaining the actual numerical value by combining the seepage deformation similarity criterion with the parameter information inside the model, and feeding the actual numerical value back to the prototype so as to analyze the piping phenomenon. The numerical analysis method for the piping phenomenon conforms to the Darcy law and the non-Darcy law, the model can truly describe the prototype when two flow states exist at the same time, the problem that a conventional model or a centrifugal test cannot achieve same-ratio zooming of the particle diameter and the model is solved, and analysis is accurate.

The invention discloses a numerical simulation method for hydraulic fracture of a core wall of a rock-fill dam. The numerical simulation method comprises the following steps of: establishing a double-axis numerical model of a particle discrete element according to a practical stress-strain curve of soil of the core wall obtained from an indoor plane strain test; establishing a core wall framework particle model according to mesomechanics parameters defined by a double-axis test of the particle discrete element; establishing a fluid model by virtue of a continuous medium model, and dispersing a control equation of of the fluid model; and simulating the hydraulic fracture by virtue of the core wall framework particle model and the fluid model. According to the numerical simulation method, on the basis of the mesomechanics parameters obtained from the indoor test, the practical mechanical property of the soil of the core wall is simulated, and the stress boundary condition of the core wall and the practical hydraulic pressure boundary condition of the upstream of the rock-fill dam are applied to conduct numerical simulation, thereby judging whether the hydraulic fracture of the core wall happens or not from a mesomechanics point of view. According to the simulation result, an improvement measure is provided in the aspects of construction or design to avoid the hydraulic fracture of the core wall, so that the numerical simulation method has guiding significance on practical engineering.

The invention discloses a real-time snowflake deposition simulation method based on a particle system model. The real-time snowflake deposition simulation method is characterized in that snowflake particles are divided into computer-simulated falling snow particles and computer-simulated accumulated snow particles. The method comprises the following steps that: (1) when the snowflake deposition simulation is started, falling snow particles are established and drawn by a computer-simulated falling snow particle model, and the falling snow particles fall from random height circularly; (2) when the falling snow particles fall to a position which is a predetermined height away from a computer-simulated scene ground, a computer-simulated accumulated snow particle model is used for receiving coordinate information of the falling snow particles, and new accumulated snow particles are drawn through a computer at the coordinate position; and (3) dot deposition and surface deposition of the drawn accumulated snow particles are realized on the computer-simulated scene ground. By the method, influence on the falling of snowflakes caused by a wind speed, a wind direction and a gravity field is reflected through the coordinate transformation of the falling snow particles; and the method is high in real-time performance and allows people to feel reality.

The invention relates to a sea surface track parallel simulation method based on a particle system. A sea surface track is generated by the method combining a real grid and a virtual particle, the parallel operation of the grid and a particle model is realized on the basis of CUDA (Compute Unified Device Architecture), and sea surface and track rendering in GPU (Programmable Graphics Processing Unit) is realized by GLSL (OpenGL Shading Language). According to the method disclosed by the invention, all the core computations and rendering are carried out in the GPU, the model computation and the rendering constitute a whole process in the GPU, the communication between the internal memory and the video memory is reduced, and the parallel processing capacity of the GPU is fully exerted. The experiment of the inventor proves that the simulation efficiency can be obviously improved under the condition of ensuring a good simulation effect.

The invention discloses a piezoelectric sensor-based on-line measurement device and method for particle size distribution, which belong to the field of gas-solid two-phase flow on-line measurement technique. The on-line measurement device is characterized in that: a collision induction probe is inserted in the middle of a gas-solid two-phase flow pipeline; a piezoelectric sensor is arranged on the collision induction probe; a signal conditioning plate and a data acquisition module are connected with the piezoelectric sensor and a signal processing system; when solid particles are collided with the collision induction probe, the piezoelectric sensor senses a particle collision signal and sends the particle collision signal to the signal conditioning plate and the data acquisition module; and the particle size distribution is obtained through signal processing software and a collision particle model. The device has the characteristic that the piezoelectric sensor is utilized to obtain the collision signal of small particle collision directly so as to realize real-time monitoring on the particle size distribution; the influence of background noise on the collision signal is reduced; and a collision dynamics principle is utilized to build a mathematical model of the collision signal and the particle size, so that the size distribution of measured particles in the pipeline is obtained.

A modeling method for a high-density discrete particle multiphase system, including the following steps: determining a model boundary; drawing up a volume sum of particle phases within each size range in the model; generating compact models of particle models within all size ranges; expanding the particles in the compact models; and obtaining a high-density particle accumulation model. The method can be used for modeling of meso-structures of particle reinforced composite materials, granular materials in soft matter, particle accumulation materials and the like, and can also be extended to short fiber reinforced composite materials and the like. The method solves the modeling problem when the particles intersect with the model boundary, and can be applied to the modeling and analysis of composite specimens with machined surfaces.

The invention discloses a urban earthquake secondary fire simulation method and system, wherein the method comprises: establishing a multi-particle model of regional buildings according to building attribute data, and performing nonlinear time-procedure analysis on the multi-particle model of the regional buildings to obtain the destructive state of each building; calculating the fire probabilityof the building according to the destructive state of each building and a regression-restricted building fire model to obtain the number and the positions of fire buildings; according to a secondary fire spread physical model and the destructive state of each building, simulating a fire spread condition caused by the fire buildings, and obtaining a building indoor fire spread state and an inter-building fire spread state; performing rendering and flue gas treatment on the building indoor fire spread state and the inter-building fire spread state by fire scene rendering and large eddy simulation, and simulating a urban earthquake secondary fire through a preset three-dimensional model. The method can improve the accuracy of earthquake secondary fire simulation and realize the high-reality display of urban earthquake secondary fire.

Disclosed is a particle-based multiphase coupling method in a virtual surgery. The method comprises the steps that particle three-dimensional models are generated for soft tissues and rigid bodies involved in the virtual surgery respectively according to triangular mesh models on the surfaces of three-dimensional tissues, a particle liquid model is established for liquid by the adoption of the SPH method, particle mechanical models of the soft tissues, the liquid and the rigid bodies are established, the soft tissues and the liquid are defined as rheological bodies, a rheological viscosity coefficient is defined between any two in-phase or any two out-phase particles of soft tissue particles and liquid particles, and collision detection and response based on boundary particles and a multiphase coupling function are carried out. The particle-based multiphase coupling method is applied to the virtual surgery and commonly used and is accurate and efficient, and the accurate and efficient multiphase coupling simulation can be achieved in virtual surgery stimulation.

The invention relates to an air flow simulating method based on physical simulation. The method converts low-speed particles into a grid model by solution of the traditional particle model, and simultaneously transfers high-speed particles to a temporary grid model while solving, and finally outputs grid model results and density field superposed by the temporary grids and renders. The invention also provides an air flow simulating system based on physical simulation. The method and the system thereof can effectively carry out simulation requirements of air containing low-speed and high-speed air simultaneously and can provide greater expression capability and more real simulation effect.

The invention discloses a method for reconstructing the three-dimensional shape of a cumulus based on a single natural image, and belongs to the field of computer graphics. The method can automatically construct the three-dimensional shape and surface details of the cumulus from the single natural image. The method comprises the steps of firstly, combining a shape from shading algorithm with cloudsurface shading information to obtain a shading constraint; secondly, calculating a boundary constraint of the cumulus by using the uniformity of contour and self-shading information of the cumulus;thirdly, constraining illumination parameters by using a two-order spherical harmonic function, and then calculating depth information of the cumulus; and finally, generating a cumulus mesh model, sampling inside the cumulus, forming a particle model of the cumulus and drawing the particle model. By introducing the shading constraint and the boundary constraint to guide the construction of a cumulus scene, the cumulus shape and detail information consistent with the image can be effectively recovered; and the obtained cumulus model is natural and rich in details.

The invention discloses an on-line estimation method for the state of charge (SOC) of a lithium ion battery based on an extended single particle model. The method comprises the following steps: 1) establishing a lithium ion battery single particle model; 2) solving the concentration distribution problem of liquid-phase lithium ions based on a BP (Back Propagation) neural network; 3) solving liquid-phase lithium ion concentration distribution of each area in the single particle model using the trained BP neural network to optimize the single particle model; and 4) implementing on-line estimation of the SOC of the lithium ion battery by adopting unscented Kalman filter based on the extended single particle model. The method considering the liquid-phase lithium ion concentration distribution of each area in the single particle model improves the simulation precision of the single particle model, and overcomes the defect of low precision of the single particle model under medium and high multiplying power conditions. The extended single particle model can better describe the nonlinear characteristic of the battery, and the SOC precision estimated by adopting unscented Kalman filter based on the extended single particle model is higher.

The invention discloses a cloudscape rebuilding method combining satellite cloud pictures and natural images. According to the method, firstly, the natural images are subjected to pixel separation; the cumulus cloud pixel and external profile are extracted out; a cumulus cloud data set is generated on the basis of the multiplex forward scattering model modeling detail cumulus cloud; secondly, initial cumulus cloud is rebuilt from the satellite cloud picture; two-dimensional profile projection sampling is performed on different view angles of the initial cumulus cloud module and is used as a feature descriptor of the cumulus cloud model; then, the optimum matching in the cumulus cloud data set is retrieved by using the directed Chamfer distance as the measure; next, the corresponding cumulus cloud model surface detail features in the cumulus cloud data set are extracted; on the basis of the laplacian mesh deformation, the detail features are transferred into the initial cumulus cloud surface; finally, sampling is performed inside the cloud; a particle model is generated; drawing is performed. The method has the advantages that the features of the two kinds of data sources of satellite cloud pictures and natural images are combined; the cumulus cloud scene with the lifelike appearance and rich details can be rebuilt.

The invention discloses a direct measurement device for the unsteady state force of a loading and fixing particle swarm of a shock wave. A high-pressure air source is connected with a shock wave pipe, small holes distributed in an equational manner are processed at a same radial section of a test section, one end of a wire penetrates through the small holes for connecting particle models in series to form a spherical array model which is fixed in the holes of the test section, a fixed base is arranged below the test section, four connecting rods penetrate through an upper cover plate of the fixed base so that a cage-shaped support top cover and a cage-shaped support bottom cover are fixedly connected with each other, one end of a pressure sensor penetrates through the upper cover plate of the fixed base to the cage-shaped support bottom cover, oil is filled among inner holes of the bottom cover, the pressure sensor is connected with a high-speed data collection system, the other end of the wire penetrates through a central hole of the cage-shaped support top cover to be fixed, and a probe of a dynamic dynamometer is connected with one end of the wire by another wire and a ring buckle. The device can be used for directly measuring the unsteady state force of the loading and fixing particle swarm of the shock wave, so that the researches on an interaction mechanism of the shock wave and the particle swarm and two-phase stream features induced by the shock wave are developed.

The invention is suitable for the technical field of unloading elephant trunks, and provides a space transhipment unloading elephant trunk design method based on a discrete element method, wherein a space transhipment unloading elephant trunk is composed of discrete elements of each segment. The design method comprises the following steps of: building a three-dimensional model of the discrete element of each segment through a three-dimensional software, and importing the three-dimensional model in a discrete element model software EDEM; creating a particle model of the material to be conveyed by the unloading elephant trunk, and importing the particle model of the material in the EDEM; determining simulation parameters, wherein the simulation parameters include operating speed and particle conveying quantity of a superior unloading device and a lower receiving device, and also include own material attributes of the particle and the discrete element, and contact attribute between the two; finishing simulation, and outputting simulation result. According to the invention, the discrete element method is introduced in the design process of the space transhipment unloading elephant trunk, movement locus of material flow in the elephant trunk can be fitted accurately, and variation of stress on each part of the elephant trunk can be calculated.

The invention discloses a soft tissue deformation modeling method based on virtual springs. The soft tissue deformation modeling method based on virtual springs is based on the spring-particle model to establish an improved real-time deformation model of soft tissue, virtual body springs are added by the topological structure soft tissue surface model combining the square and the isosceles right triangle, so that a more real deformation effect is achieved; at the position of each particle in the system, the superposition of surface springs variable is equivalent to the surface deformation of an object, the resultant force of the elastic forces of the virtual springs is equivalent to the contact force on the surface of the object; the model inherits the advantages of the classical spring particle model that the principle is simple, the model is easy to establish, the calculation speed is quick, at the same time, the model has an ability to control the deformation area.

The invention discloses a simulation method for the film formation value of mud of a slurry shield machine. Through combined usage of a granular distinct element method and a computational fluid dynamic method, a skeleton particle model and a two-phase medium mud model according with Bingham fluid characteristics in skeleton pores are established, and simulation of a film forming experiment of mud is carried out. Meso-structure parameters are obtained through laboratory test, composition of tunnel face skeleton particles is simulated, composition of fine particles in mud is simulated, grouting pressure boundary conditions are applied, value simulation is carried out, and whether a mud film is formed in the tunnel face skeleton particles is determined in a microscopic view. According to the invention, improvement measures can be brought forward to preparation of slurry according to simulation results, so a film forming effect is improved and the method is of guidance meaning to practical engineering.