121 results about "Recursive computation" patented technology

Estimating remaining capacity and remaining time of a battery device during discharging of the battery device includes determining initial state of charge of the battery device, determining discharge current of the battery device, utilizing a shooting end of discharge process to determine final state of charge corresponding to the discharge current, and determining the remaining capacity and the remaining time according to the final state of charge, the method in the invention compared with the prior art, is advantaged by less influence of estimation result of remaining capacity and run-time by discharge current, smaller estimation error, and less required recursive computation amount, namely, quicker and more accurate estimation operation.

A fault detection method in a continuous annealing process based on a recursive kernel principal component analysis (RKPCA) is disclosed. The method includes: collecting data of the continuous annealing process including roll speed, current and tension of an entry loop (ELP); building a model using the RKPCA and updating the model, and calculating the eigenvectors {circumflex over (p)}. In the fault detection of the continuous annealing process, when the T2 statistic and SPE statistic are greater than their confidence limit, a fault is identified; on the contrary, the whole process is normal. The method mainly solves the nonlinear and time-varying problems of data, updates the model and calculates recursively the eigenvalues and eigenvectors of the training data covariance by the RKPCA. The results show that the method can not only greatly reduce false alarms, but also improve the accuracy of fault detection.

The invention relates to a penicillin fermentation process failure monitoring method based on recursive kernel principal component analysis (RKPCA), which belongs to the technical field of failure monitoring and diagnosis. The method comprises the following steps: acquiring the ventilation rate, stirrer power, substrate feed rate, substrate feed temperature, generated heat quantity, concentrationof dissolved oxygen, pH value and concentration of carbon dioxide; and establishing an initial monitoring model by using the first N numbered standardized samples, updating the model by a RKPCA method, and computing the characteristic vectors to detect and diagnose the failure in the process of continuous annealing, wherein when the T2 statistics and SPE statistics exceed the respective control limit, judging that a failure exists, and otherwise, judging that the whole process is normal. The method mainly solves the problems of data nonlinearity and time variability; and the RKPCA method is used for updating the model by carrying out recursive computation on the characteristic values and characteristic vectors of the training data covariance. The result indicates that the method can greatly reduce the false alarm rate and enhance the failure detection accuracy.

The invention relates to a fault detection method of an unmanned aerial vehicle flight control system. Online detection of the fault of the actuator and the sensor of the fixed-ring unmanned aerial vehicle flight control system can be realized by the method. An unmanned aerial vehicle flight control system continuous nonlinear fault model is established on the basis of the unmanned aerial vehiclekinetic equation and the fault type; and then the unmanned aerial vehicle flight control system continuous nonlinear fault model is converted into an unmanned aerial vehicle flight control discrete time-varying fault model with the help of a nonlinear observer, and unmanned aerial vehicle flight control system fault detection is realized by using an equivalent space method. The robustness indicator is designed by aiming at the problem of poor robustness of the conventional equivalent space method under unknown interference so as to enhance the robustness of system fault detection. The extendedKalman filtering equation is utilized in the Krein space to realize recursive computation of the residual evaluation function to reduce the computational burden by aiming at the problem of high computational burden of online fault detection of the conventional equivalent space method. According to the method, quick alarm of the fault of the sensor and the actuator of the unmanned aerial vehicle can be realized so as to provide an effective basis for fault detection of the unmanned aerial vehicle flight control system.

The invention relates to a power system harmonic state estimation method, in particular, a distributed correlation Kalman filtering-based power system harmonic estimation method. The method includes the following steps of: (1) acquiring response signal data z(n) of a power system; (2) establishing a state space model of power system response sampling signals; (3) determining the value of the correlation coefficient zeta ij of neighbor nodes; (4) obtaining a state vector estimation value X^(K) at a time point k based on recursive computation through adopting a distributed correlation Kalman filtering algorithm; and (5) extracting the amplitude and phase of harmonics at the time point k. According to the distributed correlation Kalman filtering-based power system harmonic estimation method provided by the invention, the characteristics of the harmonic state of the power system are fully considered, and therefore, compared with traditional Kalman filtering communication, the distributed correlation Kalman filtering-based power system harmonic estimation method has the advantages of low communication cost, excellent anti-disturbance performance and higher estimation accuracy, and thus, a better data base can be provided for the elimination of harmonic components. The method provided by the invention can be conveniently applied to the harmonic state estimation of the power system.

The invention discloses a single phase locking device. In the device, a Kalman filter is used for combing a zero crossing point detection phase locker and a DQ coordinate system phase locker and performing Kalman filtration on frequency values, phase positions and amplitude values sent by the zero crossing point detection phase locker and the DQ coordinate system phase locker so as to obtain a final phase position, a final amplitude and a final frequency. The invention also discloses a single phase locking device which can realize a rapid and accurate phase locking function on an input signal sent by a single-phase electrical system by utilizing the advantages that sampling errors can be greatly eliminated due to the Kalman filtration and the recursive computation is high in response speed, so that the device is far better than a traditional phase locking ring in dynamic performance and static performance, overcomes the shortcomings that a traditional single phase locking method is low in speed and easy to affect, and realizes a rapid and accurate phase locking function on the phase position, amplitude and frequency of an input signal of a single-phase power grid.

The invention discloses an on-line sequence data prediction method and device. The prediction method includes: constructing an interval type-2 intuitionistic loop fuzzy neural network model; and training the interval type-2 intuitionistic loop fuzzy neural network model. The special procedure is as follows: recursively updating an average and an standard deviation to standardize sequence data samples; selecting an intuitionistic fuzzy set fuzzy rule on the basis of a dynamic clustering method of recursive computation of an approximate density center; inputting the standardized sequence data samples into the interval type-2 intuitionistic loop fuzzy neural network model with the selected intuitionistic fuzzy set fuzzy rule, outputting a sequence data prediction result, and determining whether the sequence data prediction result meets a preset precision requirement or not; completing training of the interval type-2 intuitionistic loop fuzzy neural network model; otherwise, updating an output weight, a feedback weight, an intuitionistic fuzzy set fuzzy rule center and a point difference until the output prediction result reaches the preset accuracy requirement; and inputting on-line sequence data into the trained model to obtain a prediction result.

This invention describes a quick 3D-to-2D point matching algorithm. The major contribution is to substitute a new O(2n) algorithm for the traditional N! method by introducing a convex hull based enumerator and projecting a 3D point set into a 2D plane yields a corresponding 2D point set. In some cases, matching information is lost during the projection. Therefore, to compute projection parameters, the recovery of the 3D-to-2D correspondence is important. Traditionally, an exhaustive enumerator permutes all the potential matching sets and a calibration computation is used to choose the lowest residual error computed parameters as “correct” one. Our enumerator shrinks the search space by computing the convex hull for both 2D and 3D points set, validating the potential matching cases with a horizon validation and, finally, applying recursive computation to further reduce the searching space.

An order-preserving encryption (OPE) encryption method receives a plaintext (clear text) and generates a ciphertext (encrypted text) using a software arbitrary precision floating point libraries during initial recursive computation rounds. In response to the ciphertext space reducing to breakpoint, the OPE encryption method continues computations using a hardware floating point processor to accelerate the computation. In this manner, the OPE encryption method enables efficient order preserving encryption to enable range queries on encrypted data.

A subtraction image is obtained, by a subtraction process (DSA process), from a live image and a mask image. A lag-behind part included in each X-ray detection signal is considered due to an impulse response formed of exponential functions. The lag-behind part is removed from each X-ray detection signal by a recursive computation to obtain a corrected X-ray detection signal. The live image and mask image are obtained from such corrected detection signals.

A radiographic apparatus according to this invention, when carrying out recursive computation, pixel groups consisting of detection pixels respectively corresponding to positions on a radiation detection device are sorted into locations subjected to the recursive computation and locations exempted from the recursive computation. For the locations subjected to the recursive computation, lag-behind parts are removed by the recursive computation to obtain corrected radiation detection signals. The recursive computation is not carried out at least for the locations exempted from the recursive computation. The lag-behind parts can be removed from the radiation detection signals, with a calculation amount for the recursive computation reduced by an amount corresponding to the recursive computation excluded.

Compile-time recognition of graph structure where graph has arbitrary connectivity and is constructed using recursive computations is provided. In one aspect, the graph structure recognized at compile time may be duplicated at runtime and can then operate on runtime values not known at compile time.

Corrected X-ray detection signals are obtained by removing lag-behind parts through a recursive computation based on initial values determined from lag signal value (step T2). Thus, the lag-behind parts can be removed by taking into consideration lag signal values remaining at a starting point of the recursive computation. The lag signal values are dependent on the characteristic of an FPD (flat panel X-ray detector). By removing the lag-behind parts, with the lag signal values taken into consideration, the lag-behind parts are removed from X-ray detection signals with increased accuracy, without being influenced by the characteristic of the FPD.

A subtraction image is obtained, by a subtraction process (DSA process), from a live image and a mask image. A lag-behind part included in each X-ray detection signal is considered due to an impulse response formed of exponential functions. The lag-behind part is removed from each X-ray detection signal by a recursive computation to obtain a corrected X-ray detection signal. The live image and mask image are obtained from such corrected detection signals.

An apparatus according to the invention includes a response coefficient to dose relationship memory for storing, in advance, a relationship of correspondence between intensities of an exponential function for impulse response and X-ray doses. The intensities of the exponential function determine conditions relating to an impulse response in a recursive computation performed to remove lag-behind parts from X-ray detection signals outputted from an FPD, thereby to obtain corrected X-ray detection signals. An impulse response coefficient setter sets an impulse response coefficient corresponding to an X-ray dose for an object under examination based on the relationship of correspondence between intensities of the exponential function and radiation doses. A time lag remover performs the recursive computation for time lag removal, with the intensity of an exponential function set to correspond to the X-ray dose for the object under examination. Thus, a lag-behind part is removed properly from each X-ray detection signal.