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229 results about "One step prediction" patented technology

A shale gas multi-stage fractured horizontal well post-fracturing crack parameter evaluation method and system

The invention discloses a shale gas multi-stage fracturing horizontal well post-fracturing crack parameter evaluation method and system. The method comprises the following steps: 1) aiming at a targetshale gas field, collecting static geological parameters, dynamic data and pipe column parameters of a plurality of shale gas multi-stage fractured horizontal wells; 2) obtaining values of fracturingtransformation stratum coefficients of the plurality of wells; 3) obtaining a dynamic total reserve value of each well; 4) establishing an empirical relationship between the fracturing transformationstratum coefficient and the total geological reserve of the volume fracturing transformation area according to data obtained in the steps 2 and 3; 5) obtaining the total geological reserve of the volume fracturing reconstruction area; 6) calculating the half length of the effective support hydraulic fracture; and 7) performing gas well production history fitting and/or shut-in pressure recovery well test chart fitting based on the crack half-length constraint to obtain a fracturing transformation parameter evaluation result. According to the method, the problem of high historical fitting multiplicity can be solved, a more reliable fracturing transformation parameter interpretation result is obtained, and a basis is provided for predicting the gas well productivity and making a reasonabledevelopment technical policy in the next step.
Owner:CHINA PETROLEUM & CHEM CORP +1

A Dynamic Model Identification Method for Small Unmanned Rotorcraft Based on Adaptive Genetic Algorithm

The invention discloses a small-size unmanned rotary wing aircraft dynamic model identification method based on an adaptive genetic algorithm, which relates to flight status data acquisition and optimization, dynamic model building and parameter identification, and parameter optimization validation. Firstly, status data and control data when a small-size unmanned rotary wing aircraft executes standard actions are acquired through a data acquisition system, and smoothing and filtration are conducted to eliminate wild values; then aiming at the operating characteristics of the small-size unmanned rotary wing aircraft at autonomous takeoff and landing stages, a small-size unmanned rotary wing aircraft dynamic model is built through a balance point linearization method and model parameters are identified through the adaptive genetic algorithm; and finally intelligent parameter evaluation indexes are built and the effectiveness of the model parameters is evaluated and judged through a one-step predication method. The small-size unmanned rotary wing aircraft dynamic model identification method based on the adaptive genetic algorithm solves the problem in the dynamic model identificationof the small-size unmanned rotary wing aircraft, can realize the high-accuracy control of the small-size unmanned rotary wing aircraft, and has the advantages of low testing cost, short cycle, simplecalculation, high dynamic model accuracy and weak dependence on initial values.
Owner:BEIHANG UNIV

Bayesian fitering-based general data assimilation method

The invention discloses a bayesian fitering-based general data assimilation method. The method comprises the steps of: inputting an initial value set into an analysis model in a prediction step so as to obtain a prediction set value; calculating prediction error covariance matrix by using set kalman filtering in an updating step, and updating each prediction set according to the observation value and kalman gain matrix; or, calculating importance weight of each set sample by adopting particle filtering through set prediction value, calculating the number of effective particles by utilizing normalization importance, resampling the set according to the weight to obtain updated analysis value and analysis set; or, calculating prediction error covariance matrix by adopting unscented kalman filtering, and updating each prediction set according to the observation value and kalman gain matrix; conducting next prediction and assimilation by taking the updated analysis set as the initial values of the analysis model, and repeating the prediction step and the updating step. The method can enable Earth remote-sensing observation information and land surface process model information to be effectively integrated, thus forming a land surface process information prediction system with small errors.
Owner:COLD & ARID REGIONS ENVIRONMENTAL & ENG RES INST CHINESE

Ink droplet falling-point control method in ink jet printing

The invention relates to a method for controlling and compensating an ink dropping point in an inkjet printer. The method at least comprises: a step 101, in which according to the moving speed of a word car, the jetting speed of a nozzle in the self-motion of ink drops and the distance between the nozzle and a printing medium, a graph 2 is referred and Newton's laws of kinematics is used as basis to list an equation set of horizontal projectile motion; the time ts needed for early injection is calculated; a step 102, in which according to ts, sampling time T of Kalman filtering wave is determined; according to the moving speed of a uniform speed section of the word car and the ts in the step 101, a speed curve of the word car is divided so that the sampling time of the Kalman filtering wave is more than the time of early injection; a step 103, in which according to the determined initial value of the Kalman filtering wave and the observed displacement value of the word car, one-step prediction is carried out to obtain the state variable of next time; and a step 104, in which the predicted speed value in the step 103 is utilized to carry out calculation of relevant controlled quantity; and the step returned to the step 103 for iterative prediction. The method can compensate for errors of the ink dropping point, has good precision of prediction, broadens the printing area and improves printing efficiency.
Owner:黄进 +4

Double-base MIMO radar tracking, positioning and deception jamming recognition method

The invention discloses a double-base MIMO radar tracking, positioning and deception jamming recognition method and belongs to the technical field of radar communication technology. The method comprises the steps that firstly, a residual observation vector is worked out, a measurement predicted value of a target is obtained with a one-step prediction method, and a residual equation set coefficient matrix is obtained through the predicted value; secondly, the signal to noise ratio of an echo signal is worked out, and a least square weighting matrix is worked out; thirdly, target coordinate residuals are worked out according to the observation vector, the residual equation set coefficient matrix and the least square weighting matrix, and target coordinates are worked out according to the target coordinate residuals and the target coordinate predicated values; a fitting error vector is worked out according to the least square weighting matrix and the residual observation vector, then a detection statistical magnitude is worked out, the detection statistical magnitude is substituted into a detector, an obtained value is compared with the detection threshold lambda <0>, if the obtained value is larger than the detection threshold lambda <0>, the target is deception jamming, and if the obtained value is smaller than the detection threshold lambda <0>, the target is a real target. In this way, the double-base MIMO radar tracking, positioning and deception jamming recognition method has the advantages of being high in practicability, high in precision, capable of recognizing deception jamming, small in calculation amount and high in reliability in the double-base MIMO radar tracking process.
Owner:UNIV OF ELECTRONICS SCI & TECH OF CHINA

Multi-sensor quantitative fusion target tracking method based on variational Bayesian

The invention relates to a multi-sensor quantitative fusion target tracking method based on a variational Bayesian method and a strong tracking information filtering method. According to the multi-sensor quantitative fusion target tracking method, a structure including a primary processor and a secondary processor are provided. In the primary processor, an enhanced measurement matrix H(k) and enhanced global information z (upsilon, k) are constructed; one-step prediction (k|k)-1) and corresponding covariance P(k|k-1) are calculated, global information predication z (k|k-1) is calculated, and a z (upsilon, k, 1), the (k|k)-1 and the P(k/k-1) are sent into the secondary processor. In the secondary processor, information noise variance is calculated, and (upsilon, k, 1) is sent to the primary processor, and in the primary processor, fusion estimation and corresponding covariance can be obtained through calculation, wherein please see the instruction for the formula of fusion estimation and corresponding covariance. Due to the fact that the variational Bayesian method and the self-adaptive strong tracking information filtering method are adopted in the multi-sensor quantitative fusion target tracking method, the high tracking capacity is achieved, unknown variance of noise can be estimated and measured, and the self-adaptive function can be achieved. Meanwhile, an attenuation coefficient can be estimated through an iterative method without calculating a jacobian matrix.
Owner:HANGZHOU DIANZI UNIV

Pseudo-measurement-based asynchronous track fusion algorithm with feedback maneuvering target

The invention discloses a pseudo-measurement-based asynchronous track fusion algorithm with a feedback maneuvering target. Firstly, input interaction is carried out on a model set, and the filtering initial value of each model is calculated according to the model probability and the model transfer probability; secondly, a fusion center calculates one-step prediction values on the basis of the Kalman filtering algorithm, after new sensor measurement information in the filtering period is obtained, the one-step prediction values are distributed in a time shaft sequence, recurrence is conducted on a fusion moment, information such as sensor observation matrixes, noise and model prediction are added, and asynchronous track fusion is conducted; thirdly, secondary filtering is carried out for calculating model output, output interaction is performed in the fusion center to obtain a fusion center estimated value and an estimation error matrix, and the fusion center estimated value and the estimation error matrix are fed back to a sensor according with feedback conditions. The overall precision of the algorithm is improved by introducing a fusion structure with feedback so that a better effect can be achieved in multi-sensor maneuvering target tracking.
Owner:CHINESE AERONAUTICAL RADIO ELECTRONICS RES INST

Anti-wind self-adaptive compensation method for large antenna

The invention relates to an anti-wind self-adaptive compensation method for a large antenna. The anti-wind self-adaptive compensation method for the large antenna is characterized by at least including the first step of establishing an accurate random wind load model at the position of the antenna, the second step of establishing a control-oriented model containing flexible information of the antenna, the third step of carrying out simulation on the established wind model and an antenna model, obtaining the flexible oscillation information of the antenna and calculating pointing errors, the fourth step of further predicting the pointing errors according to the Kalman filtering mode, wherein the prediction time equals the sum of an inertia time constant of a motor and an inertia time constant of a filter, the fifth step of designing a low-pass filter, solving a transfer function of the antenna model and a motor reducer model, and carrying out backstepping calculation on a predicted value to obtain a feedforward control signal, and the sixth step of feeding forward feedforward control voltage to a control system so as to enable the controlled model to produce a rigid rotation angle to offset the pointing errors caused by flexible oscillation. Through the method, pointing accuracy, electrical performance and work efficiency of the antenna are improved.
Owner:XIDIAN UNIV

No-gyro satellite gesture determination method based on tensor product multi-cell robust heavy hydrogen (H2) filtering

The invention relates to a no-gyro satellite gesture determination method based on tensor product multi-cell robust heavy hydrogen (H2) filtering, and belongs to the technical field of aircrafts. As for the nonlinear characteristics of satellite gesture dynamic equations and kinematical equations, the no-gyro satellite gesture determination method based on the tensor product multi-cell robust H2 filtering provides the multi-cell robust H2 filtering based on tensor product conversion to transform a nonlinear filtering problem into a linear filtering problem. The no-gyro satellite gesture determination method based on the tensor product multi-cell robust H2 filtering includes the steps of first establishing a state equation and a star sensor measurement equation of a gesture determination system and transforming a nonlinear system into a linear variable parameter error system by utilizing Jacobian linearization, then establishing linear parameter varying (LPV) system multi-cell model description according to tensor product model transformation and acquiring state estimation correction amount of the gesture determination system through combining with the robust H2 filtering, and last correcting gesture single-step pre-measurement acquired through a extended Kalman filter (EKF) method by utilizing the estimation correction amount to obtain a gesture estimation value. Accordingly, real-time updated filtering gain in the EKF method is avoid, and filtering calculated amount is reduced greatly.
Owner:BEIJING INSTITUTE OF TECHNOLOGYGY

Underwater terrain-aided navigation method based on adaptive sampling particle filter

The invention provides an underwater terrain-aided navigation method based on an adaptive sampling particle filter. The method comprises the steps that a state space model based on an inertial navigation position error and a measurement model based multi-beam depth-sounding sonar are built; one-step predicted particle updating is conducted through initial state distribution and the state space model, the number of particles is adjusted according to predictive state distribution by adopting a KLD sampling technology, and a predicted particle set is obtained; when a multi-beam measured value isreached, the depth, the inertial navigation guiding position and an underwater reference digital map interpolation function are measured in combination with a pressure-depth meter, and particle measurement updating is conducted through the measurement model; finally, by means of the particle set and weight which are obtained after measurement updating is conducted, aircraft position error estimation is conducted by adopting mean squared error minimization rules, and the estimated error is used for correcting the inertial navigation guiding position. Accordingly, the navigation real-time property can be improved while the underwater terrain-aided navigation precision is guaranteed.
Owner:HARBIN ENG UNIV

Method for estimating pseudo rate of spacecraft based on attitude measurement information of star sensors and angular momentum measurement information of flywheels

The invention relates to a method for estimating the pseudo rate of a spacecraft based on attitude measurement information of star sensors and angular momentum measurement information of flywheels, solving the problem of low pseudo rate estimation accuracy in the prior art. The method is as follows: adopting the star sensors to measure the attitude of the spacecraft and obtaining the differential attitude angular velocity of the spacecraft after carrying out angle difference; collecting the angular momentum information of the flywheels and obtaining the differential coefficient of the pseudo rate of the spacecraft according to the obtained angular momentum information in combination with the attitude dynamics equation of the spacecraft; carrying out one-step prediction on the pseudo rate of the spacecraft; after setting the gain coefficient of the filter, using the differential attitude angular velocity as the measured value of the pseudo rate of the spacecraft and updating the filter of the pseudo rate of the spacecraft to obtain the estimation value of the pseudo rate of the spacecraft; and adjusting the gain coefficient value of the filter according to the estimation value, thereby adjusting the estimation value of the pseudo rate of the spacecraft and finishing estimation of the pseudo rate of the spacecraft. The method is suitable for the estimation occasions of the pseudo rate of the spacecraft.
Owner:HARBIN INST OF TECH

System and method for monitoring vibration of power transformer

The present invention provides a system and method for monitoring vibration of a power transformer. The system comprises at least one vibration sensor operably mounted to the outer case of a transformer for sensing vibration of the power transformer; a spectrum analyzer for processing the vibration signal from the vibration sensor, the spectrum analyzer generating a frequency spectrum of the vibration signal and calculating a velocity rating from the frequency spectrum; a diagnosing means for evaluating the velocity rating of the vibration signal, the diagnosing means assigning a vibration grade for each velocity rating, the diagnosing means finding the maximum velocity rating; and a means for dispatching a control message to an operator when the maximum velocity rating reaches a threshold value. It can be appreciated that the mechanical health of a large-sized transformer can be managed in a systematic and efficient manner during its operation. This system can prevent accidents due to the mechanical failure of the transformer or diagnosing failure of the transformer itself during its operation. This system also can provide useful information to determine when the transformer has to be replaced and further to predict what the expected lifespan of the transformer will be.
Owner:KOREA ELECTRIC POWER CORP

Automotive radar target tracking method of iterative square root CKF (Cubature Kalman Filtering) on the basis of noise compensation

The invention discloses an automotive radar target tracking method of iterative square root CKF (Cubature Kalman Filtering) on the basis of noise compensation. The method comprises the following stepsthat: firstly, setting a system initial value, and calculating a cubature point value in a time update stage; spreading the cubature point; estimating a one-step prediction state and an error covariance square root factor; in a measurement update stage, importing a Gauss-Newton nonlinear iteration method to carry out iteration update, and calculating the cubature point during each-time iteration;spreading the cubature point; calculating measurement estimation; calcauting the square root factor of an innovation covariance and a cross covariance matrix; calculating Kalman gain; updating a current iteration state, and estimating the square root factor of an error covariance; judging whether an iteration termination condition is achieved or not; updating a current state, and estimating the error covariance square root; and in the measurement update process, regulating the noise compensation factor to optimize state estimation. By use of the method, accuracy and stability in an automotiveradar target tracking process can be effectively improved.
Owner:NANJING UNIV OF POSTS & TELECOMM

Nonlinear filtering method based on polytope differential inclusion

The invention relates to a nonlinear filtering method based on polytope differential inclusion, which belongs to the technical field of system filtering and control. The method comprises the steps of describing a nonlinear filtering error system with a PLDI (Programming Language Design And Implementation) model, converting a nonlinear filtering algorithm design problem to a linear uncertain system robust filtering algorithm design problem, designing a dynamic equation for estimated error correction solving by a hybrid robust H2/H-to-infinity filtering method, then designing a discrete nonlinear filtering equation by combining an EKF (Extended Kalman Filter) one-step prediction equation, and applying the discrete nonlinear filtering equation to a nonlinear discrete system to obtain the state estimation of the nonlinear discrete system in real time. According to the method, the nonlinear filtering design is simplified, the filtering gain is not required to be updated in real time, and the jacobian matrix is not required to be computed in real time in the implementation process, so that the computation amount is reduced greatly, the real-time performance of the nonlinear filtering is improved effectively, and the method is applicable to the design of a nonlinear filter.
Owner:BEIJING INSTITUTE OF TECHNOLOGYGY
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