340 results about "Nonlinear systems of equations" patented technology

The invention discloses a method for correcting distortion in real time based on a GPU camera and video camera. The method adopts digital image processing technology to calculate a system of nonlinear equations consisting of two radial distortion coefficients, two centrifugal distortion coefficients and two thin prism distortion coefficients by a least square method in a correction algorithm based on a planar grid model so as to obtain a space transformation equation, and carries out synchronous spatial alternation on pixel spots of an image shot by an imaging system so as to obtain an image after distortion correction. The method solves the problem of optical distortion, and improves the correction precision to sub-pixel grade; through adopting the GPU technology with parallel processing capability, the processing velocity is improved by over 40 times, realizing real-time distortion correction (over 30 frame/second) of an 1920*1080 high-definition image, and reducing the processing cost for lens optical design by 20 to 70 percent.

The invention provides an RSSI (Received Signal Strength Indication) based indoor moving target location method, which comprises the following steps: laying beacon nodes according to the law to obtain the actual distance between the beacon nodes; the beacon node sending radio frequency signals and mutually detecting the RSSI value of the received signals, and correcting parameters in an RSSI range model according to the actual distance and an attenuation value; a moving target receiving the signals sent by the beacon nodes, selecting four beacons with the largest RSSI value to participate in the positioning calculation, and utilizing the corrected RSSI range model to calculate the distance between the moving target and the four beacon nodes; preliminarily determining the prediction location of the moving target according to the coordinates of the four beacon nodes and the calculated distance; establishing a system of nonlinear equations according to the distances between the coordinates of the four beacon nodes and the moving target, taking the calculated distance and the prediction location as an unknown initial value of the system of nonlinear equations, and utilizing a Newton iterative method to find the optimal solution to obtain the location position of the moving target.

The invention discloses a method for acquiring a ball-hitting gesture and a ball-hitting speed of a ping-pong robot racket. The method comprises the following steps of: establishing a ping-pong ball flying analysis model; calculating a ball outlet speed after the robot racket hits a ball by using the model according to positions of an expected ball-returning falling point and a predicted hitting point in combination with a speed of the expected ball-returning falling point; deriving a group of non-linear equations containing the ball-hitting gesture and the ball-hitting speed of the racket according to the speeds of a ping-pong ball before and after the racket hits the ball and in combination with a rebounding model of the racket and a kinematics model of a ping-pong robot; and solving the non-linear equations by using a known optimization method, and calculating the ball-hitting gesture and the ball-hitting speed of the ping-pong robot racket.

An access point station responds to a request from a user station for contention-based access of a new traffic flow to a wireless transmission medium by applying a model of the wireless local area network to estimate delay that data packets will experience when delivered through the wireless network, in order to admit the new flow upon determining that admission will not violate quality of service requirements of neither the new flow nor of already admitted flows. For example, the access point station applies the model by determining an average packet inter-arrival rate, solving a system of nonlinear equations to determine probabilities of successful transmission, applying network stability conditions, computing an upper bound on queuing delay for the packets, computing a service delay budget for the packets, and computing an expected fraction of missed packets from the service delay budget.

The invention relates to a sound source locating method based on improved PHAT weighting time delay estimation. The sound source locating method comprises the steps that a microphone array collects four paths of sound signals, the sound signals are converted into digital signals through an A/D sampling circuit, time delay estimation algorithm processing is conducted through an improved PHAT weighting generalized cross correlation function method, a time delay estimation value is obtained, a nonlinear equation system is solved through the iteration method according to the time delay estimation value and the spatial position of the microphone array, and then the relative position of a sound source is obtained. According to the sound source locating method based on improved PHAT weighting time delay estimation, the arrangement of the microphone array is similar to the arrangement of the origin of a rectangular coordinate system and fixed length points on the x-axis, the y-axis and the z-axis; the calculated quantity is small, the device requirement is low, the speed is high, and instant locating is achieved; a sound source locating system is applied to social life, the military field and other aspects such as a video session, path planning and locating of a sniper.

The invention provides a system calibration method for a measuring head of a coordinate measuring machine based on a master ball. The system calibration method comprises the steps of a) putting the standard ball with known radius R on a working platform of the coordinate measuring machine; b) installing the measuring head at a movable end of the coordinate measuring machine, controlling the coordinate measuring machine to move the measuring head according to a proper movement trajectory and completing the point scanning of the master ball on the working platform within a measurement range, wherein the point scanning approximately and uniformly covers the surface of the entire master ball to obtain N groups of data, N is larger than or equal to 200 and each group of data comprises the measuring point numerical value of the measuring head, the three-coordinate position reading of the coordinate measuring machine and the rotating angle of a gyrator; c) on the basis of the operation in the previous step, selecting partial data of the N groups of data, performing coordinate conversion, bringing the data into a spherical constraint equation and solving an over-determined nonlinear equation set by using an improved nonlinear least square method to obtain parameters to be calibrated and complete the system calibration.

The invention discloses an adaptive indoor dynamic target UWB positioning method. The method comprises the following steps: firstly measuring a TDOA value by using a UWB positioning system; then, processing the measured TDOA value by using a wavelet analysis adaptive denoising method, outputting a reconstructed TDOA value, converting the reconstructed TDOA value into a distance difference, establishing a nonlinear equation set, and obtaining an optimal solution of the equation set; then using the optimal solution as an initial value, performing tracking and positioning on a dynamic target by using an extended Kalman filtering algorithm, and figuring out a final estimated value; and finally outputting the final estimated value. By virtue of the adaptive indoor dynamic target UWB positioning method provided by the invention, a distance measuring error caused by the influence of multipath propagation (Multipath) and non-line-of-sight interference (NLOS) in a UWB signal propagation process can be weakened and even eliminated, the positioning precision is improved, and the accurate positioning of the dynamic target in a non-line-of-sight indoor environment can be realized. The ultra wide band positioning system verifies the validity of the positioning method and realizes the indoor positioning of the dynamic target.

The invention discloses a modeling and optimized dispatching method of an electrical series-parallel system on the basis of an energy center. The modeling and optimized dispatching method comprises the following steps: firstly, establishing an electrical network, a natural gas network and an energy hub model, and coupling the electrical network with the natural gas network through an energy hub to form the electrical series-parallel system; then, taking total energy cost as a target function, and considering various constraint conditions to establish an optimized dispatching mathematic model of the electrical series-parallel system; and carrying out solving by a primal-dual interior-point method, importing a slack variable and a barrier parameter in sequence in a solving process so as to change the model into a model which only contains an equality constraint, then, importing a Lagrange multiplier to obtain a Lagrange function, and solving a non-linear equation set formed by a KKT (Karush-Kuhn-Tucker) condition of the Lagrange function by a Newton method. A constructed example simulation result indicates that an optimization effect on the electrical series-parallel system by the modeling and optimized dispatching method is superior to an independent optimization effect.

The invention discloses a transformer substation local discharge positioning method based on electromagnetic antenna array signal processing. The transformer substation local discharge positioning method is finished by a local discharge detection device, and the local discharge detection device comprises an omnidirectional antenna array, a built-in amplifier, a super-high-speed data sampling unit and a data processing unit which are mounted in a transformer substation. The positioning method comprises the steps as follows: constructing a matrix according to a concept of working out a signal wave arrival direction by a rotation invariant technology based on L-shaped antenna array signal processing; obtaining an azimuth angle of a local discharge source arriving at an antenna; and finishing planar location of the local discharge source of the transformer substation. A time delay sequence of a signal does not need to be calculated, so that the requirement on a sampling rate of an acquisition system can be lowered; and a plane coordinate of the local discharge source is obtained by working out a linear cross point in two wave arrival directions, namely working out a linear equation set in two unknowns, so that calculation of a nonlinear equation set is avoided.

A method for automatically optimizing the technological parameters in rolling metallic plate or band features use of an automatic control system composed of an in-line automatic measuring unit, a network communication unit and a data processing unit with computer. It includes measuring the rolling force F and advancing value fs, inserting them in a dyadic high-order non-linear equations to find out deforming resistance K and friction coefficient Mu, adaptive learning of the calculation module, and optimizing.

This is a nonlinear dynamic state estimation method based combined measurement by PMU and SCADA. A static module is established on the history data of SCADA. In case of non-measurement for part of nodes, conduct an accurate measure on adjacent nodes by PMU. An estimation on the non-measured nodes is made by Gauss-Seidel method.

Provided is an S-type acceleration and deceleration control method of a numerical control machine tool. Firstly, a machining program is input into a numerical control system, a numerical control device obtains necessary data, then a pentabasic nonlinear equation set referred to in S-type acceleration and deceleration control is factorized into two binary nonlinear equation sets and one unitary linear equation according to the shortest time rule and the limiting conditions of speed and accelerated speed, acceleration time and deceleration time meeting requirements are gradually solved through the Newton iteration method and the iteration correction method, then a speed curve is solved, interpolation operation is carried out finally, pulses are output, and the machining tasks of workpieces are completed. According to the method, the complex and tedious operation of existing S-type acceleration and deceleration control can be effectively avoided, and the acceleration and deceleration control method is high in precision, short in solving time, easy to understand and convenient to implement.

The invention relates to a thrust distribution optimizing method for a power positioning system of a dredge boat and belongs to the technical field of precise dredging. The thrust distribution optimizing method for the power positioning system of the dredge boat is characterized in that the power positioning system controls motions in three freedom degrees, namely the surging, the swaying and the yawing, and the optimizing processes includes: (1) a thrust distribution model of the power positioning system is constructed; (2) a target function and limit conditions are built, and optimization of nonlinear simultaneous equations is solved, namely a nonlinear mapping process from expected control amount to control instructions of all execution mechanisms under the limit conditions is performed; (3) a forward sector-shaped thrust region of a thruster is divided into sub regions, and the solution is sought in each sub region; and (4) on which condition the target function is the smallest is compared by aid of a thrust distribution control strategy to obtain the optimum scheme of thrust distribution and solve expansion capacity of a screw-rudder combination and a bow thruster. The thrust distribution optimizing method has the advantages of being high in accuracy, strong in maneuverability, simple and convenient, good in practicality, wide in application and the like.

The invention discloses an aero-engine gas path component health diagnosis method based on particle filtering. The aero-engine gas path component health diagnosis method includes the steps that a nonlinear mathematical model of an engine is established; a particle filtering algorithm is designed based on significance weight value adjustment of a neural network; finally, a gas path component health diagnosis is achieved based on the nonlinear model of the engine by the adoption of the designed algorithm. The nonlinear mode is that on the basis of a physical equation reflecting the aerothermodynamics performance of the engine, a shared working equation set among the components is established, and by the adoption of a Newton Laphson interactive algorithm, the nonlinear equation set is solved to obtain working parameters of the cross section of the engine; the particle filtering algorithm based on the significance weight value adjustment of the neural network is that a BP neural network algorithm and a typical sampling algorithm are combined, on the basis of a standard particle filtering algorithm, two steps of weight value splitting and particle adjustment are added, and therefore the phenomena of particle degradation and sample depletion are effectively avoided. The health diagnosis of gradual performance degradation and sudden faults of the gas path components within the service life of the engine can be achieved.

The invention provides an oil reservoir numerical simulation method and an oil reservoir numerical simulation device based on downhole flow control equipment. The oil reservoir numerical simulation method comprises the following steps: obtaining data of a production well, an injection well, an oil reservoir and flow control equipment; determining dynamic parameters and static parameters of each well, the oil reservoir and the flow control equipment; establishing a multi-well-section model according to the well body structure of each wheel and the flow control equipment; establishing an oil reservoir seepage model according to oil reservoir characteristics and fluid properties, wherein the oil reservoir seepage model comprises an oil-gas-water three-phase seepage equation, an outer boundarycondition and a restraint condition; coupling the multi-well-section model with the oil reservoir seepage model to generate a numerical model; establishing a geological model according to the staticparameters of the oil reservoir, and carrying out initialization on the geological model according to a relationship of original formation pressure distribution or pressure and depth as well as rock and fluid properties; and establishing a nonlinear equation set with a sparsity coefficient matrix according to the numerical model and the initialized geological model, and solving the nonlinear equation set.

An improved transformer oil-paper insulation medium response equivalent circuit parameter identification method comprises the steps that a return voltage method is adopted to measure return voltage peak, peak time and return voltage initial slope of a transformer oil-paper insulation system in a field; an extension Debye model is adopted to simulate an equivalent circuit of the transformer oil-paper insulation system; characteristic quantities of the return voltage peak, peak time and return voltage initial slope are established to solve improved mathematical models of a medium response equivalent circuit parameters, wherein the equivalent models of n relaxed branch circuits have 2n+2 model parameters to be solved, and accordingly a corresponding number of nonlinear equation systems are needed to be established through multiple return voltage testing cycles for solution; the solution of the nonlinear equation systems is converted into solution of the optimization problem of an objective function minimum value, a PSO mixed bacteria foraging optimization algorithm is adopted to identify the equivalent circuit parameters and calculate a return voltage curve, the return voltage curve is compared with a return voltage measurement curve to find that the main time constants of the two curves are identical, and the oil-paper insulation state of a transformer can be accurately judged.

The invention discloses a magnetic-levitation train suspension control method based on sliding mode variable structure control. The method comprises the steps that according to a kinetic equation of amagnetic-levitation train suspension control system, an electromagnet voltage equation and changes of a railway action surface, a dynamic model equation of the system is built; by using the linearized theory, the magnetic-levitation control system is analyzed and designed to obtain a nonlinear equation set, and the nonlinear equation set is approximated into a linearized model; according to the approximated model, the stability of the system is judged, an appropriate state variable is selected, the state variable which can be directly measured is selected as a feedback variable, and the feedback variable is subjected to state feedback control; the fundamental principle of a sliding mode control algorithm is analyzed and utilized, the magnetic-levitation control system model based on sliding mode control is built, and by adopting an appropriate control law, a design structure of a suspension controller is given. By means of the method, the performance of the controller in the suspension control system of a magnetic-levitation train can be improved, and the method can well meet the requirements for high response, stability and anti-interference performance in the suspension processof the magnetic-levitation train.

The invention belongs to the field of underwater geomagnetic aided navigation, and particularly relates to an underwater vehicle all-attitude determination method based on magnetic gradient tensor measurement. The method comprises the steps of: under a carrier system, establishing a three-dimensional rectangular coordinate system to obtain five components of magnetic gradient tensor; extracting five isolated components of the magnetic gradient tensor under a geographical system from the prestored magnetic gradient tensor database; substituting the results into a non-linear equation set about q0, q1, q2 and q3; substituting quaternion q0, q1, q2 and q3 to a transformation matrix between a substitution carrier system and the geographical system to obtain the estimated value of a pitch angle theta. The underwater vehicle locating technology based on magnetic anomaly inversion has the characteristics of being low in cost, high in sensitivity, high in anti-interference capability, free from accumulative error and the like; the problem that a single magnetometer can not independently determine the attitude by depending on the geomagnetic field can be solved; an independent and concealed way is provided for underwater vehicle attitude estimation.

The invention discloses a position and speed combined estimation method for satellite navigation, which solves the problem of real-time estimation of the position and speed of a receiver when an accurate carrier phase measured value cannot be acquired by modeling a recurrent Doppler measured value of the receiver and performing coupled solution with a pseudo-range measurement model based on the correlation between the Doppler measured value and the position of the receiver. The method comprises the following steps of: performing combined estimation on positioning and speed measurement at each new epoch moment according to the current pseudo-range measured value and Doppler measured value; and weighting least square based on a nonlinear equation system to solve an estimated position in an iterative process to replace a pseudo-range positioning result to serve as a reference position for the speed estimation of the receiver, so that the speed estimated value is gradually converged along with the position estimation. Meanwhile, estimation error comprises speed error to ensure that the algorithm convergence judgment is stricter, and the search step of an algorithm around the actual position is reduced so as to acquire higher estimation accuracy. By the method, real-time positioning and speed measurement can be reliably realized, and the method is suitable for various satellite navigation systems such as a global positioning system (GPS), a global orbit navigation satellite system (GLONASS) and the like.

The invention relates to an airborne SAR image automatic target positioning method, which convert the coordinates of a target in the SAR image into an actual geographic coordinates of the target on the earth by utilizing the flight information (location, speed, etc.) of an aerial carrier and the SAR image information (resolution, center distance, central Doppler frequency, etc.). Based on a range-Doppler equation, the invention combines an earth model equation to carry out an target location, which not only can realize an absolute localization without a control point, but also considers the influence of the earth model on positioning accuracy; on the other hand, Taylor series expansion is used for carrying out the linearization of nonlinear equations; an iterative method is adopted to solve the equation, thus improving the positioning speed; meanwhile, the initial value point of an iterative computation is appropriately selected according to the operation mode of radar, thereby controlling a converging direction in the iteration and avoiding a target confusion. As a positioning method without the control point, the automatic target positioning method of the invention has the advantages of high accuracy and high speed, thereby being capable of carrying out a real-time processing and suitable to various airborne SAR systems.

A method for measuring the space position and attitude of a target is characterized by use of said present invented large-size ball-rod instrument to measure distances, and includes such steps as measuring the distances from three fixed points on the rigid body moving in space to the three fixed point in a fixed coordinate system to obtian 9 central distances, reading them from the display of said ball-rod instrument or computer, listing 9 non-linear equations, and analyzing them to obtain the space position and attitude of said rigid body. Its advantages are simple method, low cost and high precision.

The invention relates to an initial value correcting method for space target track improvement, which relates to the space technical field. In the invention, a nonlinear spreading model of prediction error coefficient related to along-track/normal direction prediction errors is established based on the prediction error spreading regulation of a space target track; nonlinear equation sets related to the prediction error coefficient of the along-track and normal direction prediction errors are respectively established based on multiple sets of observation datum acquired in different times; the evaluation to the along-track and normal direction prediction error coefficient is completed by fitting the along-track and normal direction errors; and based on the relationship between the prediction error coefficient and the track initial value error, the track initial value correcting amount is acquired, thus realizing the correction to the track initial value. Through repeated iteration, the accuracy of the track improvement initial value is improved; the track improvement process is promoted to be reliable; and the convergence is rapid.

The invention discloses a method and a system for planning an escape route for a spacecraft. The method comprises steps of: 1) constructing a Hamilton function and a terminal constraint function of differential game based on a near circle deviation equation; 2) solving a co-state equation of the differential game to obtain an evolutionary formula for co-state quantity analysis; 3) solving an optimal control equation of the differential game to obtain an analytical expression of optimal control quantity; 4) solving a cross-section condition of the differential game to obtain terminal values ofHamilton quantity and co-state quantity; 5) solving a nonlinear equation set iteratively to obtain a saddle point of the differential game; and 6) planning the escape route for the spacecraft according to the saddle point of the differential game. According to the method and the system for planning the escape route for the spacecraft, the saddle point of the differential game of chase and escape in the spacecraft can be quickly solved, and by an optimal control law of the chase and escape corresponding to the saddle point, space threat can be evaded and a game route can be planned for the spacecraft. Therefore, the method and the system have the advantages of being correct and reasonable in design, fast in calculation, good in applicability to actual tasks, and the like.

The invention discloses a seven-parameter photovoltaic cell output characteristic modeling method based on an STFT (Short Time Fourier Transform) operator. The method comprises the steps of establishing an equivalent circuit initial model of photovoltaic cell output characteristics; defining the STFT operator to obtain a decoupling explicit equation parameter model of a photovoltaic cell; establishing a nonlinear equation set by using standard working condition basic data provided by a photovoltaic cell manufacturer, and calculating unknown parameters by using a solution algorithm; calculating unknown parameter values of the decoupling explicit equation parameter model under given working conditions; bringing the unknown parameter values under the given working conditions in the decoupling explicit equation parameter model of the photovoltaic cell to obtain a final photovoltaic cell model which comprehensively reflects photovoltaic cell output characteristics under the given working conditions. The method has the beneficial effects that the STFT operator adopted for model decoupling is not limited by a domain of definition, the expected STFT decoupling operator calculation accuracy can be set according to the needs, and the application is more flexible.

The invention discloses an artificial field source frequency domain electromagnetic apparent resistivity measuring method; the method sets a horizontal electric dipole field source and electric fieldhorizontal component measuring system according to detection or exploration needs, and employs emission and reception fixed devices for lossless detection; the method uses electromagnetic signals of different frequencies f to record a multi-frequency point electromagnetic field Ex component of certain measuring point; the method employs a first order difference derivation approximation method to calculate an electromagnetic field Ex frequency point derivative (see description) of the corresponding frequency point combination, and storing the calculated derivation information; the method uses the electromagnetic field Ex component frequency point derivative (see description) to carry out the apparent resistivity transition. The method removes the limits of using Kania apparent resistivity definition norms for solving the apparent resistivity, and can reduce the unstable calculation result risks caused by a non-linear equation group in a normal whole region apparent resistivity solving process, thus effectively improving the apparent resistivity calculation efficiency and accuracy.

The invention relates to a sun vector resolving method based on a compound eye simulated multi-channel polarization sensor. The sun vector resolving method comprises the following steps: at first, designing a structure model of the compound eye simulated multi-channel polarization sensor; then designing the selection criterion of the degree of polarization, acquiring the degree of polarization information of observed points in sky by using the multi-channel polarization sensor, and selecting the degree of polarization measurement values of a certain amount according to the selection criterion,taking three values from the degree of polarization measurement values as a set of resolving inputs and determining the weight of the set of resolving inputs; next, establishing the geometrical relationship with sun vectors according to each channel mounting matrix, establishing the constrained relationship with all skylight maximal degree of polarization by measuring the degree of polarization to obtain a system of nonlinear equations; and at last, resolving corresponding sun vectors of the set of resolving inputs by the system of nonlinear equations, and resolving weighted average on the multiple groups of sun vectors, so as to resolve the sun vectors in a module system. The sun vector resolving method can be used in sunny and cloudless weather, can be applied in cloudy weather environment at the same time, and has high robustness and environmental suitability.

Motion estimator apparatus and methods are presented in which a fully constrained nonlinear system of equations combing forward and backward displaced frame difference (DFD) equations with a plurality of displacement vector invariant (DVI) equations is solved using the input data from two image frames without approximation and without imposing any additional constraints or assumptions to obtain an estimated displacement field. Also presented is an adaptive framework for solving a system of motion estimation equations.

The invention relates to a quadruped robot control method and control device on the basis of a sine opposite angle gait and a quick table look-up method. The method comprises the following steps that: (1) combining with the opposite angle gait to analyze the leg structure of a quadruped robot, establishing the leg movement mathematical model of the quadruped robot, and adopting a novel sine gait; (2) solving a nonlinear equation set to obtain the control rate of each joint of four limbs, establishing a database which specially faces robot movement control, obtaining an accurate joint opening and closing angle through the quick table look-up method, and quickly and accurately realizing foot end trajectory control; and (3) designing a foot end trajectory control unit and a steering control unit so as to bring convenience to the access of other control systems. On an aspect of trafficability characteristics, the novel sine gait is designed and adopted, and therefore, and the robot owns high trafficability when the robot faces a complex terrain. On the aspect of operation stability, when a step taking period stops, the horizontal speed of a swing phase is zero, and therefore, the method is high in stability. The table look-up method is adopted to quickly, accurately and stably carry out the foot end trajectory control.

The invention discloses an SAR (Synthetic Aperture Rader) image fusion processing method based on a statistical model, belonging to the field of image processing. The SAR image fusion processing method comprises the steps of: first, extracting edge features of an input image, finishing self-adaption amendment processing for a local analysis window based on the edge features, and ensuring a homogeneous target in the local analysis window; then, estimating model parameters of the input image by combining with the statistical model of the input image and utilizing data of the local analysis window; and finally, completing fusion processing of the image through combining with the statistical model of the input image and depending on the optimal estimation theory. In the SAR image fusion method, the optimal estimation processing of non linear equations is converted into the optimal estimation processing of linear equations, thus the fusion process is simplified, impacts of SAR image speckle noise and the edge features in the image on the fusion are comprehensively taken into account starting from the statistical features of an SAR image and an optical image, and the fusion processing effects between the SAR image and the optical image or between the SAR images are effectively improved.