1280results about How to "Improve simulation accuracy" patented technology

A method of designing lithographic masks is provided where mask segments used in a model-based optical proximity correction (MBOPC) scheme are adaptively refined based on local image information, such as image intensity, gradient and curvature. The values of intensity, gradient and curvature are evaluated locally at predetermined evaluation points associated with each segment. An estimate of the image intensity between the local evaluation points is preferably obtained by curve fitting based only on values at the evaluation points. The decision to refine a segment is based on the deviation of the simulated image threshold contour from the target image threshold contour. The output mask layout will provide an image having improved fit to the target image, without a significant increase in computation cost.

The invention relates to a fault simulation system and a fault analysis method for single event upset in a large scale integrated circuit SRAM-type FPGA (Field Programmable Gate Array). The fault simulation system comprises a host computer and a control board, wherein the control board comprises a fault injection module, a fault detecting module and a fault analyzing module. The fault simulation system and the fault analysis method provided by the invention are flexible to use, low in cost, high in simulation precision, fast in simulation speed and free from any physical damage to a chip.

The invention relates to a hybrid real-time simulation method for an alternating current-direct current power system, and belongs to the technical field of transient simulation of the power system. The power system is divided into an electromagnetic transient side and an electromechanical transient side; a response model of voltage input and power output between the two sides, an electromagnetic transient side equivalent calculation power module and an electrochemical transient side ideal voltage source model are established; when the simulated power system is failed or violently disturbed, a network voltage equation of the power system is solved so as to obtain an interface boundary condition for the occurrence of the failure or large disturbance; and during the occurrence of the failure or large disturbance and system recovery, a simulation interactive step is adjusted for predicting a boundary parameter required by simulation, and the boundary parameter is then corrected so as to obtain the boundary condition at a sub-network interface of the alternating current-direct current system. The method effectively and accurately simulates and imitates the alternating current-direct current power system, so that the simulation result of a transient process under the failure or large disturbance at a near end of the sub-network interface of the alternating current-direct current system is consistent with the fine fully electromagnetic transient simulation result.

A method of dressing a polishing member with a diamond dresser having diamond particles arranged on a surface thereof is provided. The method includes determining dressing conditions by performing a simulation of a distribution of a sliding distance of the diamond dresser on a surface of the polishing member, and dressing the polishing member with the diamond dresser under the dressing conditions determined. The simulation includes calculation of the sliding distance corrected in accordance with a depth of the diamond particles thrusting into the polishing member.

The invention, which belongs to the virtual simulation technology field, more particularly relates to an integrated traffic simulation system based on interaction usages of macroscopic, mid-scopic and microscopic traffic simulation platforms. The system comprises a macroscopic traffic simulation module, a mid-scopic traffic simulation module, a microscopic traffic simulation module and a data collection and fusion module. The mid-scopic traffic simulation module is connected with the macroscopic traffic simulation module; the microscopic traffic simulation module is connected with the mid-scopic traffic simulation module; and the data collection and fusion module is respectively connected with the macroscopic traffic simulation module, the mid-scopic traffic simulation module and the microscopic traffic simulation module. According to the invention, on the basis of independent simulation of macroscopic, mid-scopic and microscopic traffic simulation platforms, interaction utilization of all layers of simulation systems and various simulation platform data is realized; traffic operation states of traffic flows and pedestrian flows large-scale activities can be comprehensively simulated; therefore, a technological basis can be provided for formulation of various traffic decision schemes of large-scale activities.

The invention relates to a modular multilevel converter (MMC)-based electromechanical transient simulation method and system of a flexible DC and DC power grid. The method comprises the step of building a transient simulation model, wherein the transient simulation model comprises a controlled current source-based steady-state power flow model, an AC-side transient model and a DC-side transient model, and the controlled current source-based steady-state power flow model is used for generating initial power flow data required by transient simulation. The method involves at least one additive module based on an outer ring control structure for function expansion, the additive module is used for setting a shunting signal between an AC side and a DC side of the flexible DC and DC power grid to generate a logic and is connected by the outer ring control structure of the AC side and the DC side of the flexible DC and DC power grid, and the electromechanical transient running characteristic of the flexible DC and DC power grid under different working conditions is simulated by the transient simulation model. By the method, the calculation of an initial value of a DC network is not considered, the steady-state power flow model is simplified on the premise of no influence on transient simulation accuracy and stability, and the expansibility of the model is improved.

An application program that describes processing of a workpiece by the machine tool in form of instruction steps is disclosed. A computer executes the application program and step-by-step determines based on a simulation program machine-dependent control commands for a controller. The machine-dependent control commands depend on a virtual time base that is independent of an actual time base. The computer determines based on a computer-internal model of the machine tool and the determined machine-dependent control commands expected actual states of the machine tool, thereby simulating execution of the machine-dependent control commands by the machine tool. The simulation program is implemented as control software in the controller.

The invention provides a nonlinear optimization based time-space domain staggered grid finite difference method and device. The method includes: determining finite difference coefficients; optimizing the finite difference coefficients on the basis of time-space domain dispersion relation and a nonlinear inversion algorithm; utilizing the optimized finite difference coefficients to perform elastic wave forward modeling. By the method and device, the technical problems of high middle-high frequency dispersion and low simulation precision caused by the fact that a finite difference method of taylor series expansion and space domain dispersion relation is utilized to acquire the finite difference coefficients so as to perform elastic wave forward modeling are solved, dispersion of middle and high frequency is achieved, and technical effect of simulation precision is improved.

The invention relates to a four-wheel drive pure electric vehicle hardware-in-the-loop simulation experimental system. The system comprises a drive motor and controller subsystem, an electric dynamometer and controller subsystem, torque and rotational speed sensors, a vehicle dynamic model real-time simulation subsystem and a signal detection and analysis subsystem. The system achieves pure electric vehicle four-wheel independent drive via the motor and controller subsystem, and achieves simulation of vehicle travel load via the electric dynamometer and controller subsystem. Vehicle dynamic response is achieved by operating a real-time simulation model through a real-time controller, and signal input, output and conditioning of a vehicle control unit are achieved by the aid of an FPGA (field programmable gate array). The system is capable of performing hardware-in-the-loop simulation for four-wheel drive pure electric vehicles to achieve rapid development and product testing of a vehicle drive system, and has the advantages of energy saving, safety, rapidness and low cost.

The present invention discloses a low-speed wind tunnel virtual flying experimental support device which comprises a base, an airfoil support seat, a pre-bent support rod and a three-degree-of-freedom joint. The base is fixedly installed at the center position of a wind tunnel test section basic platform. The bottom end of the airfoil support seat is vertical and is fixedly installed on the base. The cross section of the airfoil support seat is parallel to a wind tunnel flow coming direction. One end of the pre-bent support rod is connected to the top end of the airfoil support seat, the other end of the pre-bent support rod is connected to the three-degree-of-freedom joint, and the cross section of the pre-bent support rod is parallel to the wind tunnel flow coming direction. The rotation center of the three-degree-of-freedom joint is in an axis in a wind tunnel and is hinged to an aircraft model. The hinged position is provided with a fine burning device which allows the mass center of the aircraft model coincides with the rotation center of the three-degree-of-freedom joint. According to the invention, the large range three-axis attitude free support of the aircraft model in a virtual flying experiment can be realized, the structure is simple, the interference is small, the accuracy is high, and the installation and adjustment methods are simple.

The invention belongs to the field of hydraulic engineering simulation tests and particularly relates to a device and method used for river and lake relation experimental research and suitable for a river and lake intersection water system. The device used for river and lake relation experimental research and suitable for the river and lake intersection water system comprises a micro-scale river and lake model module, a model adjusting module and a river and lake relation measurement module. The device is specifically composed of a water and sand input port, a river channel micro-scale model, a lake micro-scale model, a lake opening gate, an electromagnetic water and sand separator, a lifting motor, a micro air pump, a roughness factor base pad, a ventilation hole, a spiral stirring pump, a water level gauge, a digital fluxmeter, a digital gauss meter and a surface magnetic distribution measuring instrument. According to the model test device, the invention further provides a method used for river and lake relation experimental research and suitable for the river and lake intersection water system. The method is suitable for an oversized dimension river and lake intersection water system prototype, quantitative physical analog simulation and river and lake relation space and time change measurement under the conditions of micro-scale three-dimensional space conditions.

The present invention discloses a photoelectric guidance simulation system, for the landing on a warship, consisting of a control computer, an inertial navigation system, an infrared detection gyro stabilizing system, infrared cooperation targets, a linear motion unit, an electric motor, a motion controller and a ground control station. The infrared detection gyro stabilizing system realizes stabilization of an optical axis; five cooperation targets are provided on a sliding block of the linear motion unit, and the motion controller controls the motion of the linear motion unit to bring the cooperation targets to move upward and downward and to simulate the motion of the runway decks in a vertical direction under the function of ocean waves. An infrared camera in the infrared detection gyro stabilizing system obtains images of the simulated runway decks generated by the infrared cooperation targets; operators at the ground control station identify and lock the simulated runway decks according to the image when the simulated runway decks are detected by the infrared detection gyro stabilizing system. The infrared detection gyro stabilizing system processes the five images of the simulated runway decks and sends necessary image information to the control computer which calculates a motion characteristic of the warship and a landing point position by using a photoelectric guidance algorithm. The photoelectric guidance simulation system with high precision and low cost has an important value for the development and manufacture of the photoelectric guidance landing systems.

The invention discloses a full-object verification platform and a working method of a satellite magnetic detection and control system. The platform comprises a mono-axial air floated platform, a platform computer system, an angle measuring system, a communication computer, a mini-type magnetic simulator, a satellite magnetometer, a satellite computer and an environment simulation computer. In the method, the mono-axial air floated platform is used for simulating a small satellite in space; the environment simulation computer and the mini-type magnetic simulator are used for generating an on-track magnetic field; the real satellite magnetometer and the real satellite computer sense the on-track magnetic field and complete attitude measurement and the generation of a control instruction; the platform computer computes a magnetic moment required to be output according to an control moment instruction forwarded by the communication computer and the local geomagnetic numerical value output by the magnetometer on the platform and then sends the control instruction to a magnetic moment machine; and the magnetic moment machine and the local geomagnetism act to form an actual control moment so as to control the air floated platform be stabled at a certain angle or to move at a large angle. The full-object verification platform and the working method are low in cost, high in the fidelity of emulation verification and precise in control.

The invention discloses a rapid simulation method of leakage of a high-sulfur natural gas gathering and transportation device for a marine gas field. Through analysis of leakage and diffusion distribution laws of high-sulfur natural gas in a densely populated area and optimization of a Gaussian diffusion model parameter selection method, a leakage and diffusion simulation procedure for sulfur-containing natural gas in a gathering and transportation pipeline and natural gas contained in a desulfurization device in a purification plant is acquired, and the gas leakage and diffusion result is rapidly simulated. A Gaussian model is selected, the influences of the ground roughness, the atmospheric stability and the leakage amount on gas leakage and diffusion are sufficiently considered, related parameters are corrected in combination with surroundings of a well field, the leakage and diffusion result under the four conditions of leakage of a sulfur-containing natural gas gathering and transportation pipeline, leakage of hydrogen-sulfide-containing pregnant solutions of the desulfurization device in the purification plant, leakage of hydrogen-sulfide-containing pregnant solutions of pipelines and gas leakage of pipelines of a station is rapidly and quantitatively simulated, and the longest distance that hydrogen sulfide with the concentration being 100 ppm and 1,000 ppm can reach after leakage and diffusion is obtained.

The invention discloses a medium and long term hydrologic forecasting method based on empirical mode decomposition. The medium and long term hydrologic forecasting method based on empirical mode decomposition comprises the steps that firstly, a hydrologic forecasting model is built according to the following procedures of (101) empirical mode decomposition, wherein empirical mode decomposition is carried out on a hydrologic time sequence s(t) of a forecast drainage basin, (102) kernel principle component analysis, wherein kernel principle component analysis is carried out on n intrinsic mode function components Fj obtained through empirical mode decomposition and a trend item rn, and p main components F'k are extracted, (103) building of a training sample set, wherein the training sample set is built according to the extracted p main components F'k, (104) building of a support vector machine model, and (105) training of the support vector machine model; secondly, annual runoff data of the years needing forecasting are forecast through the built hydrologic forecasting model. The medium and long term hydrologic forecasting method based on empirical mode decomposition is simple in step, convenient to realize, easy and convenient to operate, good in use effect and capable of effectively resolving the problem of low forecasting accuracy of an existing hydrologic forecasting method.

The invention relates to a simulation system for dynamic property of a pure electric automobile. The system is characterized by comprising a battery module, a motor module, a whole vehicle module, a controller module, a cycle working condition module and a display module, wherein the whole vehicle module also comprises a brake module which comprises an attachment sub-module; and the controller module performs control by using PWM chopping. The system simulates the working conditions of flat ground, climbing and cycle based on matlab software. The simulation system for the dynamic property of the pure electric automobile not only can perform analog simulation on three indexes of the dynamic property of the automobile, namely the maximum speed, the acceleration capacity and the maximum climbing capacity, but also can perform the analog simulation on the cycle working condition so as to predict the driving range of the automobile; and the system also can perform the analog simulation on the braking condition of the automobile so as to predict the minimum braking distance and braking time of the automobile; therefore, a user can optimize the optimal transmission ratio of the automobile by using a matrix operation mode so as to improve the dynamic property and the driving range of the automobile.

Method and system for efficiently controlling animated smoke which utilizes a sequence of target smoke states to generate a smoke simulation in which the smoke is driven towards each of these targets in turn, while exhibiting natural-looking interesting smoke-like behavior. This control is made possible by two new terms added to standard flow equations: (i) a driving force term that causes the fluid to carry the smoke towards a particular target, and (ii) a smoke gathering term that prevents the smoke from diffusing too much. These terms are explicitly defined by the instantaneous state of the system at each simulation time step. Thus, no expensive optimization is required, allowing complex smoke animations to be generated with very little additional cost compared to ordinary flow simulations. The invention is also applicable to animation of other fluid flow phenomena.

The embodiment of the invention discloses a method and a system for simulating the pore space fluid distribution of a core. The method comprises the following steps: establishing a digital core simulation area through a natural core sample, wherein a first area and a second area are formed in the digital core simulation area, the first area is a rock matrix, and the second area is a pore space; setting initial distribution of fluid in the second area and initial evolution conditions of an evolution equation of a lattice Boltzmann method of a Shan-Chen model according to the water saturation and the fluid type of the natural core sample, performing evolution calculation on the fluid distribution condition in the second area based on the evolution equation of the lattice Boltzmann method of the Shan-Chen model according to the initial evolution conditions and the initial distribution of the fluid in the second area, and acquiring the fluid distribution condition in the second area when the evolution calculation is stabilized. According to the method, the simulation accuracy of the fluid distribution condition is improved, and quantitative research of physical attributes of rocks is promoted.

The invention discloses an integration platform of a Matlab (matrix laboratory) simulation model based on an HLA (high level architecture), which overcomes the disadvantages that the efficiency is low, the performance is poor and the like in the prior art. The integration platform of the Matlab simulation model based on the HLA disclosed by the invention comprises a simulation model module, a configuration file module, an HLA enabling module and an RTI (real time information) system. The configuration file module is used for filling SOM (simulation object model) information; and the HLA enabling module is used for realizing the interaction between the simulation model and the RTI system. The HLA enabling module comprises a simulation parameter configuration sub-module, an input sub-module, an output sub-module, a data space sub-module, an RTI service function sub-module and a callback service function sub-module. The invention discloses an integration method of the Matlab simulation model based on the HLA. According to the integration platform and the integration method of the Matlab simulation model based on the HLA disclosed by the invention, the integration of the HLA of the Matlab simulation model is realized, and the reusability of the simulation model is improved.

The invention discloses a shale gas reservoir fluid-solid coupling multi-scale numerical simulation method. The method comprises the following steps: obtaining spatial distribution and physical property parameters of organic matters and inorganic matters, constructing a physical model of a micro-scale shale matrix, solving a micro-scale seepage auxiliary equation and a mechanical auxiliary equation, and calculating equivalent seepage and mechanical parameters of the shale matrix core scale; acquiring a natural fracture distribution situation, constructing a rock core scale physical model containing a shale matrix and natural fractures, solving a seepage auxiliary equation and a mechanical auxiliary equation of the rock core scale, and calculating equivalent seepage and mechanical parameters of a shale gas reservoir macro-scale; on the basis, simulating a hydraulic fracture by adopting an embedded discrete fracture model, and establishing a shale gas reservoir macroscopic fluid-solid coupling model; and finally, based on the structured grid, solving the shale gas reservoir fluid-solid coupling model by adopting a mixed numerical discretization method combining simulated finite difference and extended finite elements so as to realize shale gas reservoir fluid-solid coupling numerical simulation with high simulation precision and small calculated amount.

The invention provides an apparatus and methods for performing process simulation and structural analysis using a hybrid model. For example, a method of the invention automatically defines a hybrid solution domain by dividing a representation of a plastic component or mold cavity into two portions—a portion in which a simplified analysis may be conducted, and a portion in which a more complex analysis is required. The method may use as input any form of CAD data that describes the surface of a component or mold. Furthermore, the invention provides methods for simulating fluid flow within a mold cavity by automatically creating a hybrid solution domain, automatically discretizing the domain, and solving for the distribution of process variables within the solution domain.