78 results about "Convergence problem" patented technology

The invention belongs to the technical field of path or flight path planning of robots as well as low-altitude flight aircrafts, specifically relates to a path planning method of a passable area divided at unequal distance, and is used for solving the problem that existing planning algorithm has large time complexity in time and space complexity. The path planning method comprises the following steps of: calculating convex extreme points of each barrier curve; dividing the passable area by using each convex extreme point as a horizontal line; abstracting each small area obtained by dividing into a peak of a graph; forming an undirected graph by all peaks; finding out a peak serial number corresponding to the small area at which a starting point and a final point are located; finding out all paths for the undirected graph by breadth-first or depth-first scanning; finding out an actual to-be-travelled path of a moving object according to the situation on an actual map. The path planning method disclosed by the invention has the beneficial effect of overcoming the problems of algorithms of A* and the like on memory space and operation time, and overcoming a convergence problem of an ant colony algorithm at the same time. Besides, time complexity and space complexity are improved greatly in comparison with other algorithms.

The invention discloses a circuit inter-phase fault single-end ranging method, which comprises the following steps of: measuring a fault inter-phase voltage phasor, a fault inter-phase current phasor and a fault inter-phase negative sequence current phasor serving as input quantities of a circuit at a transformer substation protection installation position; calculating the voltage phasor at a fault position by using protection measured electric quantity; sequentially calculating matching error data of each point on the circuit by gradual step length increment from the beginning end of the protected circuit till a setting range of emitting a trip signal; if the protective trip signal cannot be acquired, searching the overall length of the protected circuit; and taking the point corresponding to the minimum matching error datum value as a fault point, wherein the distance between the point and the circuit protection installation position is a fault distance. The method is not affected by distributed capacitors, load current, fault resistors and operation mode of a system, has no false root problem of solving an equation or non-convergence problem of an iteration method, and has strong practical value.

The invention discloses a method for analyzing loop closing risks based on an interconnection switch in a power distribution network. The method comprises the steps that firstly, the voltage difference of the two sides of the interconnection switch is acquired, a power transmission network CIM model and a power distribution network CIM are spliced to form a loop closing path, and the loop impedance of the loop closing path is calculated; secondly, the loop closing steady-state current and the maximum impact current are worked out according to the voltage difference of the two sides of the interconnection loop and the loop impedance of the loop closing path; lastly, safety verifying is carried out on all devices on the loop through the loop closing impact current and the loop closing steady-state current, and whether loop closing can be carried out or not is judged. The method does not depend on the telemeasuring data of the power transmission network, the computing time is short, the computing result accuracy is high, the convergence problem does not exist, the change of the power transmission network can be followed in real time, the power transmission network loop closing risks under the most situations can be solved, the power outage caused by the loop closing failure is avoided, and the high social benefits and economic benefits are achieved.

The invention discloses a slide face boundary method for calculating the slope stability. In the slide face boundary method, only a slider is taken as a calculated object for slope stability analysis. The invention further discloses a comprehensive glide force-antislide force stability coefficient calculation method and a main glide force method based on the slide face boundary method. The method disclosed by the invention has the advantages that the non-convergence problem of an existing slope stability calculation method is solved, the slope step-by-step stability failure analysis, realizes easy calculation can be implemented, the calculation results with a conventional limited equilibrium slice method can be compared, and new stability coefficients have different physical significances, so that the current slope monitoring results can be applied to the slope stability evaluation.

The invention discloses a Newton method power flow calculation method which changes a Jacobi matrix with iteration and node types. A PQ node calculates a Jacobi matrix element by using an ai value and a bi value which are calculated by given values Pis and Qis in the first-time iteration. A PV node and all nodes in the subsequent iteration calculates the Jacobi matrix element by using a conventional method. The method solves a convergence problem of a rectangular coordinate Newton method power flow calculation method in the analysis of a power system containing a low impedance branch in such a way that the PQ node adopts the Jacobi matrix calculation method in the first iteration process and which is different from that in the subsequent iteration processes. The method of the invention can be reliably converged when he conventional rectangular coordinate Newton method are not convergent, is less than the number of iterations than the prior art. The Newton method power flow calculation method can not only solve the convergence problem of the rectangular coordinate Newton method power flow calculation method in the analysis of a power system containing a low impedance branch, but also can calculate the power flow of the normal power system without any adverse effect.

The invention discloses a judgment method for an initial position of a permanent magnet synchronous motor rotor. The judgment method comprises the following steps: firstly using a pulsating high-frequency voltage injection method to acquire a primarily estimated rotor position; and then injecting a disturbing signal in a positive direction on a primarily estimated quadrature axis to estimate the rotor position; and finally, judging the polarity of a magnetic pole according to the estimated rotation speed direction, so as to acquire the initial position of the motor rotor. The judgment method can solve the convergence problem of the polarity of the magnetic pole when the pulsating high-frequency voltage injection method is adopted to detect the initial position of the rotor, so that the initial position of the rotor can be effectively estimated without injecting pulse current in the positive direction on the direction axis.

The invention discloses a rapid decomposing method load flow calculating method suitable for a branch system comprising small impedance. The method comprises the step of inputting original data and initializing voltage, the step of forming a node admittance matrix, the step of forming a coefficient matrix B' and a coefficient matrix B'' of a modified equation and decomposing a factor table, the step of setting iteration count and a convergence mark, the step of calculating the inactive power unbalance amount delta Q, the step of judging whether the absolute value delta Qmax is smaller than the convergence accuracy epsilon or not, the step of calculating the active power unbalance amount delta P, the step of judging whether the absolute value delta Pmax is smaller than the convergence accuracy epsilon or not, the step of calculating the balance node power and the inactive power of a PV node, and the step of calculating the branch power. Part of elements in the coefficient matrix B' of the modified equation of a rapid decomposing method are modified, and the convergence problem produced during analyzing the branch system comprising the small impedance with the resistance not equal to zero in rapid decomposing load flow calculation is solved. When a convention method is adopted to calculate non-convergence, the rapid decomposing method load flow calculating method can carry out convergence reliably.

The invention discloses a vehicle network data distribution congestion control method based on a congestion game. The problem that network congestion cannot be effectively solved in the prior art is mainly solved. The method comprises the implementation steps that 1, a congestion game model of a vehicle network is built according to an existing network congestion game model; 2, a utility function of the vehicle network related to service quality and transmission delay is constructed according to a utility function in the congestion game model; 3, a potential function of the congestion game model of the vehicle network is built according to the utility function and is corrected; 4, the convergence problem of the congestion game is converted into potential function value minimization based on the wardrop theory and the congestion game equilibrium existence principle; 5, a slot time distribution matrix is obtained through a heuristic algorithm, and a vehicle selects to carry out transmission or waiting according to the slot time distribution matrix. The method can effectively reduce network congestion, and can be used for vehicle network dense scenes and congestion control of safety relevant application data distribution.

The invention relates to a projection algorithm for generating curved surface non-interference five-axis processing locus, belongs to the milling processing technology field and aims to guarantee that a final knife contact point is on an original workpiece curved surface, improve processing precision and guarantee relatively good processing surface quality. According to the algorithm, a knife contact point of a cutter projected on a triangular sheet model is selected as an initial point; the shortest distance from the initial point to a workpiece curved surface is calculated, and a corresponding point on the workpiece curved surface is further calculated; a tangent plane on the workpiece curved surface passing the corresponding point is established; the cutter is projected to the tangent plane to acquire projection points on the tangent plane; an adjusting search step algorithm is executed for an oscillation convergence problem; the projection point on the tangent plane satisfying an error is taken as the knife contact point. The algorithm is advantaged in that based on a Newton-Raphson algorithm, a continuous iteration method based on the tangent plane is employed, that the knife contact point is on the original workpiece curved surface is guaranteed, and calculation precision of the cutter contact point is improved.

The present invention discloses an adaptive sub-band audio feedback suppression method. The method comprises the steps of segmenting an input signal according to a sampling sequence to obtain data blocks; allowing the data blocks to pass a sub-band filter to obtain sub-band signals of a power amplification signal and an input signal; allowing the sub-band signals to pass an adaptive sub-band feedback filter to deduce a microphone feedback sub-band signal generated by a speaker signal, performing weighing energy analysis and statistics on the sub-band signal, and correcting the adaptive sub-band feedback filter; synthesizing input sub-band signals expect the feedback sub-band signal and recovering to obtain a time domain signal; and sending the recovered time domain signal to the speaker for sound amplification. The method has the advantages that the signal filter is segmented into sub-bands, so that the correlation between the sub-band signals is lowered, a convergence problem of the adaptive filter is solved, data processing amount of the system is reduced, the feedback suppression processing efficiency is improved, the sound gain of the sound amplification system is improved, the sound amplification quality is improved, and the sound gain can be increased by over 6 decibel stably, at most 15 decibel.

The invention discloses a novel linearization power flow calculation method. Direct current power flow is the most widely-applied power flow calculation linearization method at current, which has high solving speed and without causing a convergence problem; however, the method has low calculation precision, and two important electrical variables which refer to a node voltage and circuit reactive power cannot be solved, so that the application range of the method is limited. On the basis, the invention provides a novel linearization power flow calculation model with higher precision; by virtue of the model, the calculation efficiency can be ensured while the circuit reactive power can be solved at the same time; an example simulation result proves that the novel linearization power flow calculation method maintains high efficiency of the conventional direct current power flow, has higher precision and higher applicability, and can solve the circuit reactive power.

In a peer-to-peer collaboration system, deltas containing data change commands are organized in a persistent data structure called a delta log. The delta log is organized into blocks, which are the largest division in the delta log. In turn, blocks contain groups, groups contain chains and chains contain deltas. Delta blocks are used to implement priority deltas that are used to limit the collection of data change commands that must be transferred. Within a block the deltas are organized by groups, each of which is a set of deltas organized into chains. The delta group in used to determine which deltas to purge. The chains are ordered by increasing creator ID of the endpoint that created the chain. Organizing the delta log in this fashion allows the log to be “walked” to detect convergence problems. To achieve causality-preservation, each delta has a list of dependencies representing other deltas that must be executed before the current delta can be executed. The dynamics manager uses the ability to do (execute) and undo commands to perform roll back and roll forward operations on deltas in order to achieve convergence.

The invention discloses a fast decoupled flow calculation method of a modified coefficient matrix. The fast decoupled flow calculation method of the modified coefficient matrix comprises the steps of: adopting a way of firstly performing Q-V iteration and then performing P-theta iteration, and modifying partial elements of a coefficient matrix B' of the modified equation of P-theta iteration; multiplying reactance of a low-impedance transformer branch with a correction factor alpha and not multiplying the reactance of a normal branch with the correction factor. By modifying partial elements related to the small reactance in the modified equation coefficient matrix B', the convergence problem of the fast decoupled flow calculation method when being used for analyzing a relatively high resistance containing low-impedance branch system is improved. When convergence is failed by adopting the conventional fast decoupled flow calculation or the conventional patent algorithm, the fast decoupled flow calculation method can realize convergence reliably. As the fast decoupled flow calculation method can effectively solve the convergence problem of conventional fast decoupled flow calculation method which is used for analyzing the relatively high resistance containing low-impedance branch system and also can perform flow calculation on a common system, no negative influence is generated.

The invention discloses a vision-based lunar rover positioning method in a sandy environment, which comprises the following steps: extracting and enhancing characteristic points; matching and tracking the characteristic points; and carrying out motion estimation. Through the above steps, the change of the position and direction of the lunar rover can be acquired. The positioning algorithm disclosed by the invention avoids the problems that characteristic points on the lunar terrain in a sandy environment are sparse and are not robust enough, ensures the quantity and quality of the characteristic points extracted in the sandy environment, and improves the motion estimation accuracy; from the perspectives of dimensionality reduction, reasonable selection of search windows, estimation of search directions and the like, the vision-based lunar rover positioning method improves the characteristic matching and tracking efficiency; and by using a method based on RANSAC (RANdom SAmple Consensus), the vision-based lunar rover positioning method can effectively solve the non-convergence problem caused by too much error data and improve the robustness of a mileometer with respect to the non-convergence problem.

The invention discloses a continuum structure non-probability reliability topological optimization method under displacement and global stress mixed constraint. According to the method, first, a density filtering method is adopted to obtain unit density through design variables; second, a relaxation rule is adopted to calculate displacement and stress of a structure, and stress integration function constraint is utilized to process global stress; third, a vertex combination method is utilized to obtain an upper bound and a lower bound of a displacement and stress integration function; fourth,optimal feature displacement is adopted to replace non-probability reliability indexes to solve a convergence problem, and an adjoint vector method and a composite function derivation rule are adoptedto solve sensitivity of the optimal feature displacement; and last, a mobile progression method is adopted to perform iterative computation till a corresponding convergence condition is met, and an optimal design scheme meeting reliability constraint is obtained. Through the method, the influence of uncertainty on stiffness and strength performance of the continuum structure is reasonably represented in the topological optimization design process, effective weight reduction can be realized, and it is ensured that the design is secure and economical.

The invention discloses a voltage initial value setting method of load flow calculation with a rectangular coordinate newton method, comprising the following steps: threshold value of a low impedancebranch circuit is determined, and the branch circuit less then the threshold value is defined as the low impedance branch circuit; initial value of a voltage image part is taken as 0.0, a set value ofa voltage real part of a PV node and a balance node is taken: the initial values of the real part of node voltage at two sides of the low impedance branch circuit are chosen, so as to meet the formula: ei=kej; the undetermined voltage initial value of the real part of the other nodes are taken as 1.0. By improving the voltage initial value setting method, the convergence problem of load flow calculation with the rectangular coordinate newton method can be effectively solved. The method has the characteristics of clear concept, simple programming and good convergence. The calculation only aimsat the low impedance branch circuit to specially choose, for a normal branch circuit, the initial value is chosen according to a level starting way still, thereby having not effect on the convergenceof the load flow calculation without a low impedance branch circuit system.

The invention relates to a budget estimate planning method and the technical field of networks, in particular to a power construction budget estimate planning method and a networking system thereof, realized by a computer system. The networking system comprises a design system inner network and budget estimate system software and is connected with an external network by a firewall and a gateway; the system software also comprises a system main module and a planning module (1), a resource management module (2), a sample database management module (3), an approval module (4), an information statistics and issue module (5) and a system interface and management module (6). The method adopts a tree structure recursive model to solve the problems of the online dynamic regulation and the traversal of a budget tree structure, adopts a multiplex iterative algorithm to solve the convergence problem of an aggregate project amount and adopts a Web Service program to solve the problems of data transmission and information share between distributed real-time heterogeneous databases. The invention already finishes 20 thousand of budget estimate planning and relates to construction amount amount over ten billion.

The invention provides a network loss equivalence load model-based power flow calculation initial value setting method, which comprises the steps of carrying out network loss equivalence load model-based DC power flow iteration calculation on a power grid to obtain a DC power flow voltage phase angle phasor theta*<DC> of a power grid node; by employing the theta*<DC> as an initial value of a node voltage phase angle, calculating a voltage amplitude estimation value phasor V*<F> and a phase angle estimation value phasor theta*<F> of the node through a quick decoupling method; and evaluating the voltage amplitude estimation value phasor V*<F> and the phase angle estimation value phasor theta*<F>, calculated through the quick decoupling method, of the node to obtain a newton method power flow initial value. The network loss equivalence load model-based power flow calculation initial value setting method is conducive to improvement of the power flow convergence and has the advantages that DC power flow calculation is free of a convergence problem and calculation through the quick decoupling method is relatively simple.

The present invention provides a double-iterative blending blind restoration method for a motion blurred image. The method comprises: calculating three frequency spectra of the to-be-restored motion blurred image, wherein the three frequency spectra include a conventional frequency spectrum, an expansion logarithm frequency spectrum and an expansion logarithm frequency spectrum without a main line; using a general iterative image blind restoration method to initially restore the blurred image, and roughly estimating a motion blurred point spread function with strong spatial domain constrained Hough transform and weak spatial domain constrained Hough transform; using a double-iterative method to perform multiple rounds of rough estimation; using a combined symmetry and power measurement and search method to accurately estimate a motion direction; using a method for searching a global turning point in the expansion logarithm frequency spectrum without the main line to accurately estimate a motion distance; and creating an optical transfer function and using a conventional image restoration method to restore the blurred image. According to the method, the estimation of the motion blurred point spread function is accurate and the restoration effect is good. In addition, the method has the advantages of high noise immunity, good stability, no convergence problem, simplicity for parameter setting and the like, and can be widely applied to motion blurred image restoration in various occasions.

A single-channel optimum method and system for constraining constant modulus interference in the process of civil aviation ground-air communication comprises that very high frequency amplitude-modulated signal received by the antenna is converted into intermediate frequency signal; the converted intermediate frequency signal is implemented with the process of digital conversion and filtration extraction; the carrier frequency of the signal after the process of filtration extraction is estimated; and then the process of adaptive notch filtering is implemented; the signal, the amplitude modulation and carrier wave of which are removed, is implemented with the process of orthogonal transform; the signal after the process of orthogonal transform utilizes non-linear least squares to estimate the constant modulus interference signal; the signal after the process of orthogonal transform and the estimated constant modulus interference signals are delivered into a subtracter together and then the two signals are subtracted; the resistive component of the subtracted signal is taken to be multiplied with the carrier wave signal for modulation; and then the high-frequency clutter is removed through a low-pass filter and the audio frequency signal is output. The single-channel optimum method for constraining the constant modulus interference can estimate the modulation and the phase of theconstant modulus interference in real time and avoid the convergence problem of the ordinary adaptive interference constrain method; two methods of batch processing and recursion are presented and the convergence property of the recursion method is proven.

The invention provides an electric power system node voltage automatic adjusting method, and refers to a cycle process; the method can adjust for many times, can solve the sensitivity of a PV node onan off-limit node voltage, and can solve the sensitivity of a reactive compensation node on an off-limit node voltage, thus obtaining the optimal PV node voltage adjusting amount and the reactive compensation node reactive adjusting amount. In an adjusting process, no artificial intervention is needed except giving the target voltage and voltage allowable deviation of each off-limit node, thus solving the problems that an artificial node voltage adjusting mode is time and labor wasting; in electric power system trend analysis, the method can greatly save work hours, thus improving the calculation and analysis efficiency. When the two sensitivities are solved, the automatic adjusting method mainly employs calculation methods that have no convergence problem, such as matrix inversion, matrixpartitioning, and matrix multiplication; the whole adjusting method is good in convergence, and can automatically finish the adjustments.

The invention discloses a method for calculating an irregular defect scattering sound field under the action of a rotation sound field. Due to the fact that defects constantly change relative to the space position and postures of the sound field in the nondestructive testing process based on the rotation sound field, a traditional scattering sound field computing method has the defects that the calculation amount is large and the calculation process is complex, the irregular defect scattering sound field is hard to calculate. Therefore, a method that Kirchhoff approximation and the T matrix scattering numerical algorithm is combined to solve the scattering sound field is adopted, the scattering source method is introduced into the T matrix algorithm to solve the problem that convergence is hard to carry out when a T matrix is calculated for cracks, layering and other difficult non-spherical defects, and the convergence problem is solved. The efficiency of the overall detecting technology is taken into consideration, the dimension reduction processing is carried out on the scattering process through POD, and a finite dimension freedom degree system is used for approaching an original scattering model. By means of the method, the mechanism of the action of the irregular defects and the mechanism of the action of any rotation detecting sound field can be defined, the purpose of quantitative description can be achieved, and a most basic theory basis of the ultrasonic non-destruction testing study is achieved.

The invention discloses a pseudo range phase integrated ionosphere delay solving method which includes the steps of obtaining epoch ionosphere delay based on pseudo range observed value and constructing an observation equation, obtaining the change of ionosphere delay between epochs based on phase observed value and constructing an observation equation, constructing a corresponding method equation and jointly solving the pseudo range phase integrated ionosphere delay. The absolute ionosphere delay amount is solved by using the pseudo range observed value, and the ionosphere delay changing amount is solved by using the differential phase observed value between epochs. The integration is conducted based on the basis to solve convergence problem in a phase smooth pseudo range observed value method. The method does not rely on long-term continuity of phase data, prevents fuzziness resolving by using phase observed value, and improve the solving precision and reliability of the ionosphere delay. The method is applicable to satellite basic navigation and ionosphere delay calculation in satellite-based enhanced system, and calculation of ionosphere delay correction number for user positioning and service system.

The invention discloses a rigid-plastic material, which is characterized in that the rigid-plastic material is rigid. A non-probabilistic reliability topology optimization method for continuum structures with strength fusion constraints is presented. Firstly, the relative density of elements is obtained by density filtering method from design variables, and then the displacement of the structure is calculated by finite element method. The stress of the structure is calculated by relaxation method, and the global stress is treated by p-form stress synthesis function constraint, then the upper and lower bounds of displacement and global stress are obtained by vertex combination method. The convergence problem is solved by replacing the original non-probabilistic reliability index with the optimized eigendistance, and the sensitivity of the optimized eigendistance is solved by using the adjoint vector method and the compound function derivative rule. Finally, the moving asymptotic methodis used for iterative computation until the corresponding convergence conditions are satisfied and the optimal design scheme satisfying the reliability constraint is obtained. The invention can realize effective weight loss and ensure that the design itself gives consideration to safety and economy.

The invention discloses a two-dimension phase fast unwrapping method using an L<0> norm cost function; the method comprises the following steps: numerical realization of solving a differential equation algorithm, firstly converting a differential relation into a difference relation corresponding to discrete data, then carrying out difference equation iteration solving, wherein each step treatmentis carried out on the basis of the previous step treatment result in the iteration process, and the difference [delta] [phi] between the two processing steps becomes the solving important content. Thetwo-dimension phase fast unwrapping method using the L<0> norm cost function can solve the problems that an existing phase unwrapping method is low in efficiency when processing big data blocks. Themethod aims at the conventional minimum norm unwrapping method, analyzes the cost function characteristics, and provides the two-dimension phase fast unwrapping method complying with the L<0> norm cost function; combined with a data partitioning scheme, the method can solve the full low frequency aberration convergence problems in the linear differential equation, and improving the unwrapping efficiency.