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33 results about "Polynomial method" patented technology

The polynomial method was based on ideas from computer science. For example, suppose we have a fairly low degree polynomial over a finite field. Suppose we write a table of the values of the polynomial, and then the table gets corrupted, so that one third of the entries are replaced by errors.

Intelligent vehicle lane change path planning method based on polynomial and radial basis function (RBF) neural network

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.
Owner:BEIJING UNIV OF TECH

Wind power modeling and performance evaluating method based on confidence equivalent power curve band

The invention relates to the field of data processing, in particular to a wind power modeling and performance evaluating method based on a confidence equivalent power curve band. The wind power modeling and performance evaluating method includes the steps that preliminary screening and rejection are conducted on an abnormal data sample; wind speed is divided into three regions, and a kernel density estimation method is used for obtaining wind speed and power probability distributions in each region through statistics to obtain the Copula function in each region; the maximum likelihood estimation method is adopted to obtain confidence equivalent power boundary model in the corresponding region; a piecewise cubic Hermite interpolating polynomial method is used for reconstructing missing datato complete original data sample cleaning; the average value of the confidence bandwidth ratio is used as the model performance evaluation index, a d-fold cross validation method is used for validating the upper and lower boundary models in different regions, when the index is basically stabilized at a certain constant value, the up and lower boundary models of the different regions are determined; a sliding time window method is adopted to updating data, the deviation degree of the confidence bandwidth ratio is used as a triggering condition, and the up and lower boundary models are updatedwhen the deviation degree exceeds a certain threshold value.
Owner:NORTH CHINA ELECTRIC POWER UNIV (BAODING)

Mixed integer nonlinear programming model for solving combination problem of hydroelectric generating set

InactiveCN107844864APreserve the actual engineering characteristicsHigh precisionForecastingPower stationPolynomial method
The invention provides a mixed integer nonlinear programming model for solving the combination problem of a hydroelectric generating set, and belongs to the field of hydroelectric scheduling operation. The mixed integer nonlinear programming model for solving the combination problem of a hydroelectric generating set is characterized by utilizing a polynomial fitting technology to process the complicated power station nonlinear relation, providing a quartic equation polynomial fitting method of water level-capacity of reservoir-tailwater level-out flow, and based on a quadratic polynomial of head loss of the hydroelectric generating set, describing the generating head of the hydroelectric generating set as a multivariate quartic function of capacity of reservoir and flow; considering aboutthe influence of the head on the output, providing a binary quadratic polynomial method of accurately representing the output head and the generating flow of the hydroelectric generating set, introducing 0-1 variable, solving the startup-shutdown problem of the hydroelectric generating set, obtaining the head-flow-output relation three-dimensional fitting surface of the hydroelectric generating set, and satisfying the fine calculation demand of the output of the hydroelectric generating set under the variation head; and realizing calculation with high efficiency by means of a mature MINLP solver. The mixed integer nonlinear programming model for solving the combination problem of the hydroelectric generating set fully considers the complicated nonlinear relation of the hydroelectric systemand has the advantages of reducing the linear error and significantly improving the solution accuracy, compared with a classic MILP model. Besides, the obtained set combination and load distributionresult can preferably reflect the practical operation situation of the hydropower station.
Owner:DALIAN UNIV OF TECH

Rotor position measurement method of transverse flux switch reluctance motor without position sensor

The invention discloses a rotor position measurement method of a transverse flux switch reluctance motor without a position sensor. The rotor position measurement method comprises the steps of settingan initial position angle of the motor, and applying a high-frequency pulse voltage to an A phase; adding a step to the initial position angle of the motor, and sequentially calculating an inductancevalue corresponding to each angle to obtain an A phase angle-inductance relation curve; dividing the inductance curve in a mechanical angle period into six regions, performing fitting by employing aquadratic polynomial method to obtain an ideal inductance curve, analyzing the ideal inductance curve, selecting appropriate low-threshold inductance TL, and obtaining a starting phase logic in the mechanical angle period according to a relation between three-phase inductance and the TL in each region; simultaneously calculating a three-phase inductance value from a three-phase injection high-frequency pulse voltage, comparing the three-phase inductance value with the starting phase logic, and determining a starting phase; and injecting a next conduction phase of the starting phase into the high-frequency pulse voltage, switching off the starting phase after a commutation threshold is reached, and conducting the next phase to achieve commutation running. The rotor position measurement method is easy to implement and is relatively high in accuracy.
Owner:南通大学技术转移中心有限公司

Aircraft posture coupling rapid and stable control method based on mechanical arm driving

The invention relates to an aircraft posture coupling rapid and stable control method based on mechanical arm driving. According to the aircraft posture coupling rapid and stable control method, a mechanical-arm-driven aircraft posture coupling kinematics model considering joint mass center bias factors is established, and the influences of initial linear momentum and angular momentum are considered and serve as the model basis for the design of a control law; and a reference posture limited time convergence trajectory is determined based on a polynomial method according to initial posture errors of an aircraft, and the determined polynomial coefficients need to satisfy joint angle, joint angular velocity and joint angular acceleration constraints. The aircraft posture coupling rapid and stable control method based on mechanical arm driving does not need to consume a chemical propellant, and can prolong the service life of an on-orbit aircraft; and the aircraft posture coupling rapid and stable control method based on mechanical arm driving can ensure that aircraft posture errors converge within reasonable given time, has good dynamic performance, and can ensure that the mechanicaljoint motion satisfies the angle constraint, angular velocity constraint and angular acceleration constraints.
Owner:CHINA ACAD OF LAUNCH VEHICLE TECH

Polynomial Method of Unscented Kalman Filter Based on Higher Order Moment Matching

InactiveCN104038180BImprove stabilityImproved Approximation AccuracyDigital technique networkNonlinear filterState prediction
The invention discloses a polynomial method of an unscented Kalman filter based on high-order moment matching, and belongs to the technical field of nonlinear filtering. It includes the following steps: establish the state equation and measurement equation of the nonlinear system; determine the random distribution characteristics of the initial state, including its mean, covariance and higher-order moments, the distribution characteristics of noise, and the initial measurement value; based on the state of the previous moment Estimation and state equations, using multi-layer unscented transformation to calculate the distribution characteristics of random variables for one-step state prediction; based on the state prediction and measurement equations of step 3, using MUT to calculate the distribution characteristics of state prediction measurements; using Kalman gain to fuse states Predict and measure the data to calculate the distribution characteristics of the optimal state, and complete the one-step estimation task of the nonlinear system. This method is used to solve the accuracy and calculation stability problems of nonlinear filters in the actual application process. Combining with the existing sampling strategy, high-order moments and multiple symmetric sampling are used to improve the accuracy.
Owner:CHONGQING INST OF GREEN & INTELLIGENT TECH CHINESE ACADEMY OF SCI

A method for measuring the static contact angle of liquid droplets

A method for measuring the static contact angle of a droplet. First, drip water on the surface of a material, and then use a digital imaging device to take pictures of the droplet on a plane perpendicular to the surface of the material to obtain an image of the droplet, and use an edge detection operator to measure the droplet. The droplet image is processed to obtain the droplet edge; then the droplet edge point data is transformed from the Cartesian coordinate system to the polar coordinate system, and then the polynomial fitting method is used to fit the droplet edge, and then the droplet edge is transformed from the polar coordinate system to Cartesian coordinate system, and finally calculate the slope of the droplet edge at the solid, liquid, and gas three-phase junction point, and obtain the static contact angle from the slope. In the present invention, the rectangular coordinate system is converted into the polar coordinate system first, and then the edge of the droplet is fitted. Since the edge of the droplet is closer to a polynomial in the polar coordinate system, the calculation accuracy of the contact angle is higher, and it is converted into polar coordinates. The number of points involved in fitting the edge after the system is more, and the anti-interference ability is stronger.
Owner:NORTH CHINA ELECTRIC POWER UNIV (BAODING)

Method and device for solving polynomial error position

The invention discloses a method and a device for solving an error location polynomial. The method comprises the following steps of: inputting coefficients of odd-term syndromes and even-term syndromes into a first period of each turn of iteration, and calculating a modification value required by the subsequent turn of iteration; judging whether the modification value is 0 in a second period of each turn of iteration, and outputting the coefficients and intermediate quantity of an intermediate polynomial, which are required by the subsequent turn of iteration, according to a judgment result; and calculating the coefficients of the error location polynomial, which are required by the subsequent turn of iteration, in the second period of each turn of iteration, according to the modification value, the coefficients of the error location polynomial, which are required by this turn of iteration, and the coefficients and the intermediate quantity of the intermediate polynomial, which are required by this turn of iteration. By adoption of an IBM iteration circuit for solving the error location polynomial provided by the invention, key path time delay is greatly reduced, and the problems about area and time sequence are solved in an equilibrium way, so the method and the device for solving the error location polynomial can be applied to high-frequency data transmission.
Owner:SHENZHEN STATE MICROELECTRONICS CO LTD
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