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306 results about "Model equation" patented technology

Method for estimating power battery capacity and charge state based on data model fusion

The invention relates to the field of estimating power battery parameters and states, in particular to a method for estimating the power battery capacity and charge state based on data model fusion. In order to improve the estimation precision of the power battery charge state of an electric vehicle, the invention provides the method for estimating the power battery capacity and charge state based on the data model fusion, and the method comprises the steps of carrying out an aging experiment for a power battery, obtaining a three-dimensional response surface relation formed by the open-circuit voltage, charge state and available capacity of the power battery at different aging degrees, establishing an equivalent circuit model for the power battery, inputting the actual measurement end voltage and charge and discharge currents of the power battery into a model equation of the power battery, identifying model parameters of the equivalent circuit model of the power battery and the maximum available capacity and a charge state initial value of the power battery, and estimating the charge state of the power battery. The method of the invention can be used for estimating the capacity and charge state of the power battery at different aging degrees, and is high in practicality and estimation precision.
Owner:BEIJING INSTITUTE OF TECHNOLOGYGY

Electro-thermal simulation method for FS (Field Stop) type IGBT (Insulated Gate Bipolar Transistor) transient temperature characteristic

The invention provides an electro-thermal simulation method for FS (Field Stop) type IGBT (Insulated Gate Bipolar Transistor) transient temperature characteristic. An FS type IGBT switching transient working process is actually tested and is analyzed by being combined with an IGBT working principle and a semiconductor physical principle to determine that the IGBT transient temperature characteristic is mainly influenced by life of internal excess carrier, so that the electro-thermal simulation method is established. The method comprises the following steps of: actually testing carrier life values extracted at different temperatures to acquire a relational expression of the carrier life and temperature; calculating through an empirical value formula to acquire a relational expression amongthreshold voltage, transconductance, emitter saturation and current as well as the temperature; and adding temperature related parameters into an FS type IGBT current tailing stage current analyticalexpression and a switching transient model equation set and calculating to acquire transient working waveform of the FS type IGBT at different temperatures. The electro-thermal model simulation method provided by the invention simultaneously has the advantages of simple parameter calculation and high accuracy.
Owner:NAVAL UNIV OF ENG PLA

Modeling method for unmanned aerial vehicle (UAV) dynamic emergency collision avoidance area

ActiveCN102854883ATargetedGuarantee the success rate of collision avoidancePosition/course control in three dimensionsJet aeroplaneModel method
The invention discloses a modeling method for an unmanned aerial vehicle (UAV) dynamic emergency collision avoidance area. The modeling method can be used for establishing an emergency collision avoidance area envelope when the UAV meets an intrusion aircraft. The method comprises the following steps of: firstly judging whether flight conflict is present between the UAV and the intrusion aircraft through a conflict detection algorithm, determining a power-driven of UAV emergency collision avoidance according to the flight course of the intrusion aircraft if the flight conflict is present between the aircrafts, establishing a UAV dynamic emergency collision avoidance area model equation by analyzing the emergency collision avoidance power-driven process, and obtaining the emergency collision avoidance area boundary value and the required collision avoidance power-driven time by resolving the model equation. According to the method, the flight information of the intrusion aircraft is acquired in real time, so that the UAV emergency collision avoidance area is dynamically established. The method can provide dual reference information, namely the shortest collision avoidance distance and the required collision avoidance power-driven time, and the collision avoidance success rate is guaranteed to the greatest degree; and moreover, the collision avoidance area envelope area is reduced, unnecessary airspace waste and collision avoidance power are avoided, and the method has high real-time property.
Owner:BEIHANG UNIV

Method and apparatus for estimating random jitter (RJ) and deterministic jitter (DJ) from bit error rate (BER)

An apparatus and method provides prediction of BER for an interface between ICs, such as a processor and a memory device, without using special test equipment. A known data pattern or PRBS is transmitted to a receiver, which compares the received data values with expected data values to determine if a bit error has occurred in an embodiment of the present invention. A center of data eye and the edge of the data eye are sampled (over sampled) in order to determine if a bit error has occurred in an alternate embodiment of the present invention. A first counter is used to count the total number of bits sampled and the second counter is used to count the number of errors that occurred in the total number of bits sampled. In an embodiment of the present invention, the first and second counters are logarithmic counters that include overflow protection. The counter values are output to a processing device to perform the BER calculation in an embodiment of the present invention. A plurality of BER values is then obtained for corresponding offsets. A subset of the plurality of BER values corresponding to the plurality of offsets is selected. An inverse of the standard normal cumulative distribution (NormSlnv) function for respective BER values is calculated. Two linear fits on the transformed BER values and offsets are performed to obtain the x-intercepts that correspond to a DJ component and the slopes corresponding to a RJ component. The DJ and RJ components are used with the Fibre Channel jitter model equation to predict BER as a function of transition density and offset value.
Owner:RAMBUS INC

On-board SAR image automatic target positioning method

The invention relates to an airborne SAR image automatic target positioning method, which convert the coordinates of a target in the SAR image into an actual geographic coordinates of the target on the earth by utilizing the flight information (location, speed, etc.) of an aerial carrier and the SAR image information (resolution, center distance, central Doppler frequency, etc.). Based on a range-Doppler equation, the invention combines an earth model equation to carry out an target location, which not only can realize an absolute localization without a control point, but also considers the influence of the earth model on positioning accuracy; on the other hand, Taylor series expansion is used for carrying out the linearization of nonlinear equations; an iterative method is adopted to solve the equation, thus improving the positioning speed; meanwhile, the initial value point of an iterative computation is appropriately selected according to the operation mode of radar, thereby controlling a converging direction in the iteration and avoiding a target confusion. As a positioning method without the control point, the automatic target positioning method of the invention has the advantages of high accuracy and high speed, thereby being capable of carrying out a real-time processing and suitable to various airborne SAR systems.
Owner:BEIHANG UNIV

A 38 Lumped Reactor Modeling Method for Continuous Reforming Unit

ActiveCN102289579AHigh precisionEliminate production bottlenecksCatalytic naphtha reformingSpecial data processing applicationsBroyden fletcher goldfarb shannoTest analysis
The invention discloses a modeling method for a 38-lumping continuous reforming device reactor. The modeling method comprises the following steps of: 1) subdividing a reaction material into 38 lumping components; 2) constructing a reforming reaction network comprising 86 reactions; 3) building a reforming reaction dynamical model equation group on the basis of the reaction network by combining a reactor structure; 4) accumulating an influence of catalyst inactivation to estimation of each reforming reaction dynamical parameter, determining 86 model parameters, and estimating the model parameters by adopting a method combined with a gradient descent method and a broyden fletcher goldfarb shanno (BFGS) variable scale optimization algorithm based on an industrial data sample. On the basis ofa dynamic mechanism of reforming reaction, the precision of a reforming model is improved by fully using an advanced computer technology and a test analysis condition and the simulation of a reforming device is closer to the actual reaction, so that an instruction having a practical significance is provided for eliminating the production bottleneck and optimizing each operating parameter, and theeconomic benefit of the device can be enhanced.
Owner:ZHEJIANG UNIV

Experiment table for measuring mounting rigidity and damping of sealing ring

The invention discloses an experimental table for measuring mounting rigidity and damping of a sealing ring. The experiment table comprises a base, wherein a bottom plate is connected to the base; a supporting column is connected to the bottom plate; an actuating vibration table is connected with the supporting column; a positioning circular ring is rigidly connected with the actuating vibration table; a supporting ring is fixed on the positioning circular ring; a measured sealing ring is mounted in a groove inside the supporting ring; a quality loop is flexibly mounted on the measured sealing ring and forms clearance fit with the supporting ring; the supporting ring is connected with a sensor mounting plate; a function generator is connected with the actuating vibration table through a power amplifier; a high-pressure fluid sub system is connected with the supporting ring; two laser displacement sensors mounted on the sensor mounting plate are connected with a computer through a controller; by resolving a forced vibration model equation caused by supporting excitation of the quality loop and the supporting ring, the rigidity and damping parameters of the measured sealing ring are obtained. The experiment table can be used for researching the rigidity and the damping parameters after the sealing rings which are of different diameters and made from different materials are mounted under different pre-compression amount.
Owner:TSINGHUA UNIV

Method of estimating SOC and impedance of lithium battery on line

The invention belongs to the battery identification and estimation field, and specifically relates to a method of estimating SOC (State of Charge) and impedance of a lithium battery on line. The method of estimating SOC and impedance of a lithium battery on line can improve the accuracy of a batter model equation so as to improve the accuracy of the Kalman filtering algorithm, by adding the impedance parameters, such as the direct current impedance, the polarized capacitance and the polarized resistance of the lithium battery, into the battery model equation, and can optimize the deficiency that the accuracy of the traditional Kalman filtering algorithm depends on the model accuracy. And at the same time, the method of estimating SOC and impedance of a lithium battery on line enables the dynamically changed impedance parameters to participate in every SOC estimation process, so that the estimated value of the battery residual electric quantity can have higher accuracy. At last, the method of estimating SOC and impedance of a lithium battery on line can obtain the reference value of the current healthy state for the lithium battery by referring to the corresponding battery electrochemistry impedance spectrum, thus being conductive to assisting the user to preferably master the current service life of the lithium battery by estimating the impedance parameters obtained through real time estimation. The method of estimating SOC and impedance of a lithium battery on line can realize high accuracy of estimating SOC and the service life of the lithium battery on line.
Owner:UNIV OF ELECTRONICS SCI & TECH OF CHINA

High-precision difference method for simulating transport diffusion problem

The invention relates to a numerical simulation method in the engineering field such as environment, water conservancy and the like and discloses a high-precision difference method with strong universality for series typical model equations suitable for solving problems of flow and heat-mass transfer of various fluids, in particular the problem of transport diffusion. Aiming at the defects that conventional limited difference format of the prior water environment simulation only has low one-order or two-order precision, while the prior multi-step differential equal-high precision method generally relates to a lot of grid points, has over complex construction mode and is most based on quite regular even rectangular meshes, and the like, the invention provides a high-precision difference method under an uneven mesh. The method adopts an indeterminate coefficient method to determine an influence coefficient between a point to be solved and an adjacent point in a difference equation so that the difference format reaches maximum-order precision under the mesh structure. Because the difference format is constructed by adopting an uneven grid system, the density of the mesh distance can be flexibly adjusted according to the size of the variation gradient of physical quantity to be solved, and the simulation precision and efficiency are effectively improved.
Owner:BEIJING NORMAL UNIVERSITY
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