366 results about "Index function" patented technology

Beamforming method that allows a high speed and high accuracy beamforming with no approximate interpolations. This beamforming method includes step (a) that generates reception signals by receiving waves arrival from a measurement object; and step (b) that performs a beamforming with respect to the reception signals generated by step (a); and step (b) including without performing wavenumber matching including approximate interpolation processings with respect to the reception signals, and the reception signals are Fourier's transformed in the axial direction and the calculated Fourier's transform is multiplied to a complex exponential function expressed using a wavenumber of the wave and a carrier frequency to perform wavenumber matching in the lateral direction and further, the product is Fourier's transformed in the lateral direction and the calculated result is multiplied to a complex exponential function, from which an effect of the lateral wavenumber matching is removed, to perform wavenumber matching in the axial direction, by which an image signal is generated.

Disclosed is an implementation method for simplifying a complicated message-passing function in a decoder for decoding block codes encoded with low-density parity-check (LDPC) codes and only using a summator and a shifter to simplify the hardware structure of the decoder, in which method the input interval of the message-passing function for binary representation of a message input is divided and the respective divided intervals are linearized to allow the calculation of the output of the message-passing function without using a memory. Based on the fact that the message-passing function is similar in structure to an exponential function, the linearized intervals are set to make the maximum value expressible in each digit of the binary representation as the boundary of the intervals.

A charge pump circuit includes, in a preferred embodiment, a plurality of serially-connected pump stages, each of which is driven by one or more associated clock signals for the stage. The amplitude of the clock signals associated with a respective one of the pump stages differ in amplitude from that of the clock signals associated with at least one other pump stage. As a result, the additional voltage achieved by each successive pump stage may be progressively larger for each successive pump stage. An exemplary charge pump circuit provides clock signals which increase in amplitude with each successive pump stage, and provides with each successive pump stage an output voltage having a magnitude that is a multiplicative factor of the magnitude of the input voltage for the stage. Consequently, the output voltage achieved by the exemplary charge pump circuit is an exponential function of the number of pump stages within the charge pump circuit.

The invention provides a multi-constraint locus planning method of a spatial free floating mechanical arm. The method can satisfy requirements for dynamic coupling, joint driving capability limitation, arresting opportunity and multiple optimizing indexes of a spatial robot. A driving joint motor realizes an autonomous arresting task to a non-cooperative object. The multi-constraint locus planning method comprises the steps of establishing a multi-member dynamic model of the spatial robot; establishing the locus of each joint of the mechanical arm based on a Bessel curve, converting constraint and optimizing index functions in a joint locus designing process to function of a Bezier curve control point, so that locus programming is finally represented by the Bezier curve control points as a nonlinear optimization problem of the optimizing parameter; converting the locus planning problem of the spatial robot to a multi-constraint and multi-object optimization problem, performing searching on the optimization problem by means of a nonlinear optimization method, obtaining an optimal solution, and finishing multi-constraint locus planning of the spatial free floating mechanical arm.

The invention relates to an intelligent vehicle lane change path planning method based on a polynomial and radial basis function (RBF) neural network. The intelligent vehicle lane change path planning method comprises the following steps that: the state information of obstacles and lane change vehicles in lanes are detected and determined according to a vehicle-mounted sensor, and the state information comprises positions, speed, acceleration and shapes; the lane change vehicles and the obstacles are geometrically covered, and in addition, a lane change path model using the time as the independent variable is built; boundary conditions of the lane change vehicles are obtained by the dynamic RBF neural network; the lane change path parameter is subjected to traversing in a certain range according to a certain step length, and the calculation of a polynomial method is combined to obtain the lane change path set under the specific boundary conditions; index functions for evaluating the merits of the lane change patch performance are defined, the optimal path in generated lance change paths is screened according to the index functions and is applied to the practical lane change process of vehicles; and whether the RBF neural network is updated or not is determined according to the merits of the boundary conditions of the generated lane change paths. The neural network has good self-adaption capability, so that the problem that the RBF neural network structure is oversize or undersize is solved.

The invention relates to one visual frequency compression codes macro block coding mode selection method, which comprises the following steps: predicting move and processing rapid speed and lose estimation after exchange and volume; during computation, processing exchange parameters as zero; in speed estimation computation, establishing non-zero parameters sum, and number and journey sum and relation module; defining one index function to meter non-zero parameter number and journey sum impact on speed with each real code for one block to update index list according to low pass filter; according to speed and aberration estimation to process macro coding module selection.

A torque sensor system having an index function and ascertaining a torque between an input shaft and an output shaft connected to each other via a torsion bar, includes: a magnetic unit having a magnetic pole wheel for generating a magnetic field, the magnetic unit being rigidly connected to one of the two shafts; a flux ring unit having a flux ring system for converting and conducting the magnetic flux generated by the magnetic unit, the flux ring unit being rigidly connected to the other shaft; and a sensor unit having at least one first magnetic field-sensitive sensor element for sensing changes in the magnetic flux through the flux ring system, the sensor unit being mounted in a stationary manner relative to the flux ring unit. The index function is implemented with the aid of an index magnet and a further magnetic field-sensitive sensor element.

A transmission circuit includes: a modulated signal generator for outputting a modulated signal; an envelope detector for outputting an amplitude modulated voltage; an amplitude roll-off LPF for attenuating the amplitude modulated voltage by using a damping property represented by an exponential function in which an argument is exponentially proportional to a frequency; a power-supply-voltage generator for generating a power supply voltage in accordance with an amplitude value of the amplitude modulated voltage; a phase detector for outputting a phase modulated signal; a phase roll-off LPF for attenuating the phase modulated signal by using a damping property represented by an exponential function in which an argument is exponentially proportional to an offset frequency with respect to a center frequency; and an RF power amplifier.

The invention discloses a first-arrival travel time picking method and device for a seismic signal comprising noise, and the method comprises the following steps: carrying out the decomposition of an original seismic signal s(t) comprising noise through a noise adaption complete set EMD (Empirical Mode Decomposition) method, and obtaining a series of finite IMF components from high frequency to low frequency and residual components; screening out a plurality of high-frequency IMF components according to an EIF effective index function, and carrying out the wavelet threshold denoising; carrying out the accumulation and reconstruction of the high-frequency IMF components denoised through wavelet threshold denoising and the high-frequency IMF components which are not denoised, i.e., obtaining the denoised seismic signal x(t); initially determining the first-arrival travel time t0 through an improved sliding time window energy ration method; calculating a local extreme value in a time window comprising the moment t0 through an AIC information criterion method, wherein the time corresponding to the extreme value is the precise first-arrival travel time t. According to the invention, the method can effectively improve the seismic noise inhibition effect and improve the picking precision of the first-arrival travel time, and creates the conditions for the accurate processing and explanation of the subsequent seismic data.

Embodiments of the present application disclose a method and apparatus for dividing a logistics region. One embodiment of the method includes obtaining a distribution address of a historical order within a region to be partitioned;clustering the distribution address of the historical order as a data point to be clustered to obtain a candidate clustering set comprising at least one candidate clustering; calculating a distance index function of the candidate clustering, and splitting and/or merging the candidate clusters based on a distance index function, wherein the distance index function isused for characterizing the distribution characteristics of the distance between the data points in the clusters and the clustering centers and the distance characteristics between the clustering centers, so as to obtain at least one cluster whose distance index function satisfies preset conditions; dividing the region to be divided into at least one logistics region according to the geographicalposition range covered by the clustering which satisfies the preset conditions of each distance index function. This embodiment improves the accuracy of the logistics area division.

The invention discloses an unmanned aerial vehicle three-dimensional track multi-target particle swarm global planning method, which comprises the following steps: (1) establishing an environment model according to a flight environment, and adopting a digital map technology when the flight environment of an unmanned aerial vehicle is processed; (2) establishing a flight path planning model according to the environment model established in the step (1); and (3) applying a particle swarm optimization technology to the flight path planning model in the step (2), and giving an improved multi-target backbone particle swarm global flight path planning algorithm with few control parameters. The method has the advantages that the three-dimensional global multi-target flight path planning model ofthe unmanned aerial vehicle is established, three index functions of flight path length cost, threat cost and concealment cost and corresponding constraint requirements are given, a multi-target particle swarm global planning method with few control parameters is provided, and the practicability of path planning is enhanced.

The invention discloses a speed controller parameter optimization method in consideration of primary frequency modulation and ultralow-frequency oscillation suppression. According to the method, a single machine infinite system containing an optimized unit and an equivalent infinite power supply is established, a comprehensive optimized index function is established under the stimulation of frequency step signals of the primary frequency modulation test requirement by regarding the unit openness/power response curve rise time, stabilization time and reverse regulation power as performance indexes of primary frequency modulation and regarding damping torque coefficients of a speed controller and a water turbine system in an ultralow frequency band as ultralow-frequency oscillation damping performance indexes, the primary frequency modulation performance and the damping level can be considered by obtained speed controller parameters, and technical means is provided for optimization of the speed controller parameters and suppression of ultralow-frequency oscillation.

The invention provides an investment effect evaluation method for county power distribution networks, which comprises the following evaluation steps: (1) establishing an index evaluation system and determining evaluation indexes; (2) determining an index evaluation function, and determining the threshold value of each index according to index data statistics; (3) acquiring fundamental data of a power distribution network correlated with evaluation indexes of an area to be evaluated, and verifying the integrity and validity of the fundamental data; (4) normalizing the evaluation indexes; (5) calculating the score of each evaluation index and the comprehensive score of each evaluated area through weighting; and (6) according to the evaluation results, sequencing the investment effects of selected evaluated areas in a descending order, analyzing main indexes influencing the sequencing of investment effects, and for lower-ranking evaluated areas, making an optimizing adjustment strategy. According to the invention, the acquired index data of each evaluated area is subjected to normalized processing by using an evaluation index function, and then the score of each evaluation index and the comprehensive score of each evaluated area are calculated according to a combination weight so as to find out the weak links existing in a power distribution network, thereby quantifying the investment efficiency of a county power distribution network, and providing reference and basis for distribution network planning and decision-making departments.

The invention discloses a neighborhood windowing based non-local mean value CT (Computed Tomography) imaging de-noising method for mainly improving original CT projected image data by adopting a search region and weight calculation in a non-local mean value technology. The main implementation process of the neighborhood windowing based non-local mean value CT imaging de-noising method comprises: (1) setting a mean square error of a Gaussian window for a collected original CT projected image; (2) finding all the similar blocks in the search region; (3) calculating a Gaussian Euclidean distance between the similar blocks and a block where a current spot locates; (4) calculating a similarity weight by utilizing a negative index function, wherein the level of similarity increases along with the increase of the weight; (5) obtaining a product of the similarity weight and a distance weight to obtain a mixed weight; (6) performing weighted average on all the pixel point values in the search region by using the mixed weight to obtain a corrected pixel point value; and (7) reconstructing de-noised projection image data to form a final chromatographic X-ray image. By the adoption of the neighborhood windowing based non-local mean value CT imaging de-noising method disclosed by the invention, the purpose of restoring the original image better and improving the de-noising performances for the image can be realized.

The invention relates to a moving horizon method-based multi-unmanned aerial vehicle cooperative attack task allocation method and belongs to the multi-unmanned aerial vehicle coordinated control technical field. The method includes the following steps that: the ability function of unmanned aerial vehicles is established, a calculation method of a multi-unmanned aerial vehicle cooperative attack position is provided through the jacobian matrix of the ability function; a unmanned aerial vehicle damage cost index function, a voyage cost index function and a multi-unmanned aerial vehicle cooperative task assignment model are established; and a moving horizon method is utilized to model a maneuver decision-making problem into an optimized control problem, and a whole maneuver target approach process is discretized temporally and spatially, optimal maneuver strategies can be solved piecewise, and an optimal decision-making method for a multi-unmanned aerial vehicle cooperative attack task can be provided. With the horizon method-based multi-unmanned aerial vehicle cooperative attack task allocation method of the invention adopted, a higher target gain value and damage efficiency can be obtained, and multi-unmanned aerial vehicle cooperative attack ability can be improved.

A method is provided for updating a check node in a low density parity check (LDPC) decoder, including: transmitting log-likelihood ratio (LLR) messages from variable nodes to a plurality of check nodes; decomposing the LLR messages in a plurality of node messages for each check node; and updating each check node using a modified function g(x), which is a function g′(x) comprising a sum operation of exponential functions based on the node messages.

A computer implemented method for guiding an under-actuated marine surface vessel in tracking a desired trajectory comprises expressing a predetermined vessel trajectory as a set of straight line segments, determining a desired current line segment, and determining the vessel's current position. A cross-track error and the derivative of the cross-track error are then determined. Next, a radius R of the line-of-sight (LOS) circle using a newly introduced exponential function is determined. Intersection points M and N between the LOS circle and the current desired line segment are determined. A desired heading angle is determined as the angle between the line of sight and a predetermined fixed reference line. A drift detection algorithm is built into the proposed guidance scheme to detect situations whereby the ship moves parallel to its desired trajectory for an extended period of time without being able to correct for the cross track error.

The invention relates to an electric power system line weakness evaluation system and method based on multi-attribute analysis. The system comprises an EMS information obtaining module, a line topology importance degree calculation module, a line correlation coefficient calculation module, an economic loss calculation module, a hidden failure rate calculation module, a line integral weakness calculation module and a weak line screening module. The method comprises the following steps of obtaining trend information and historical information of each line in an electric power system; obtaining the topology importance degree index of each line, the correlation coefficient index of each line, the hidden fault rate index of each line and the economic loss index of each line due to line breaking according to the trend information and the historical information of the line; building an integral weakness index function; performing calculation by using the topology importance degree index, the correlation coefficient index, the economic loss index and the hidden fault rate index of the line as input data of the integral weakness index function to obtain the integral weakness index of each line; and obtaining the weak line in the electric power system through setting the critical weakness index.

The present invention provides a battery remaining electrical charge/remaining capacity estimating method which makes it possible to obtain a convergence value of a battery open circuit voltage with high accuracy and in a short time.

The method includes a voltage estimating step of obtaining a stable open circuit voltage estimated value after a lapse of desired time, the step including: a step of using an approximate function including a plurality of exponential function terms of time and a plurality of coefficients, stopping charge or discharge operation for a predetermined time, measuring a battery voltage over time during the time and using an obtained relation between the battery voltage and the time as a basis to determine the coefficients; and a step of determining at least one power coefficient of inferior logarithm of the exponential function terms based on temperature by expressing the coefficient as a previously obtained function of temperature.

The invention belongs to the field of airplane aeroelasticity tests, and relates to an airplane ground test scope, in particular to an automatic amplitude modulation frequency scanning method for an airplane servo elasticity frequency response test. Control plane overloads are fed back to automatically adjust a frequency scanning amplitude value, on the premise that safety of a control pane structure is guaranteed, control plane deflection exciting force of all frequency scanning points is kept maximum so that sufficiently large airplane structure response can be excited, the signal to noise ratio of a response signal of an airplane-flight control combined circuit is improved, test errors are reduced, and reliability of a test result is improved. Meanwhile, the adjusting process of an excitation signal amplitude value is controlled through construction of a hyperbolic tangent-exponent function, violent response of a control plane caused by sudden changes of the excitation signal amplitude value is prevented from happening in the process of frequency scanning, and safety of the control plane structure is ensured. In addition, the advantages of a real-time simulation system of a computer are brought into full play, in the process of the test, people only need to slightly click a mouse, so that parameters such as control limit overloads and excitation signal cycles can be adjusted, and the automatic amplitude modulation frequency scanning method is high in practicability.

The invention provides an error data identification method applicable to secondary equipment of a power supply system. The method comprises the following steps: if difference between two adjacent sampling values of the secondary equipment is greater than a preset threshold, then the current data are the error data, and the error data are discarded. The theory is as follows: firstly, as primary equipment of the power supply system has large inductance and capacitance, in the case of serious fault of the power supply system, the current value or voltage value of the power supply system does not suddenly changes but changes according to an exponential function curve; secondly, a mutual inductor of the primary system and an internal mutual inductor of the secondary equipment which are used for signal transformation have a maximum range limit, so the sampling value of the second equipment has a maximum value; and thirdly, if the sampled signal has frequency, the sampled signal has the frequency characteristics. The threshold of the permissible maximum sampling value difference can be set by integrating the three steps with the specific characteristics of the secondary equipment, such as amplitude corresponding to sampling point number and sampling conversion of each cycle.