53 results about "Pseudo-spectral method" patented technology

The invention relates to the technology of UAV (unmanned aerial vehicle) control, aims at proposing a UAV locus and attitude cooperative control method and ironing out a defect in the locus planning for each UAV of a conventional UAV cluster, and can effectively reduce the requirements for the positioning precision of the UAV. Therefore, the invention provides a cluster UAV locus and attitude cooperative control method for a safety domain, and the method comprises the following steps: 1, control-oriented four-rotor-wing UAV locus and attitude model building: giving full consideration to the inherent characteristics of a four-rotor-wing UAV and the dynamic factors in flight, and building a locus and attitude mathematic model for the four-rotor-wing UAV; 2, cluster center locus planning: achieving the obstacle avoidance path planning for a cluster UAV central point based on a pseudo-spectral method; 3, safety flight region optimization: completing the optimization of a cluster UAV safetyflight envelope and a cluster UAV optimal formation configuration; 4, distributed cooperative controller design. The method is mainly used in a UAV control occasion.

The invention discloses a gait generation and optimization method for a biped robot. The method is characterized in that a gait library of the biped robot is constructed in a finite state machine according to a target pose of the state of the biped robot; mutual switching conditions among all states of the robot are set and triggered; in each state switching process, a joint cubic interpolation method is used for planning the movement track of support legs, and a gauss pseudo-spectral method is used for optimizing the movement track of swing legs; and finally, the gait of the biped robot in different motion modes is generated by the finite state machine. According to the gait generation and optimization method for the biped robot, the constraint of ZMP is not considered, and all the bipedrobots with or without the sole edges of the feet can generate the walking track by the method; and the planning process is simple and operable and is more suitable for online generation, and the biped walking robot can stably walk and finish walking, running, jumping and other actions by matching with a simple control strategy.

Belonging to the technical field of flight, the invention relates to an optimal design method for reentry trajectory in the radioactive prohibited area comprising the steps of S1, setting up aircraft three-degree freedom motion model, flight process constraint model and flight trajectory terminal constraint model; S2, constructing radioactive prohibited area model (img file='DDA0001082531380000011.TIF' wi='350' he='105' /), wherein, Rk refers to threat coefficient, C refers to ratio coefficient, K/N refers to radar signal-noise ratio, and Rd refers to radar ranging coverage; threats of any point in the radioactive prohibited area in unit time are quantized to describe degree of threat in the radioactive prohibited area; S3, deeming integral of threat coefficient of the radioactive prohibited area model as property indicator function and aircraft as control object to construct optimal control problem; S4, solving the optimal control problem in S3 by Guass pseudo-spectral method to draw the optimal flight trajectory of aircraft to break through the radioactive prohibited area. The optimal design method for reentry trajectory in the radioactive prohibited area enhances capacity of strategic delivery and breakthrough of hypersonic speed aircraft and facilitates aircraft to break through radar detection and tracking.

The invention discloses a spectral method-based multi-component gas concentration analysis method. The spectral method-based multi-component gas concentration analysis method comprises the following steps: determining a background gas absorption response spectrum in a wide spectrum range; determining a standard sample absorption response spectrum in the wide spectrum range; determining an absorption response spectrum of to-be-detected mixed gas in a standard sample; determining the concentration value of each component in the to-be-detected mixed gas in the standard sample. Background automatic calculation of an absorption spectrum signal is realized according to an asymmetric reweighted penalty function lease square method; the problem of water vapor and component anti-interference erroris solved by using a differential type anti-interference wavelength selection algorithm, and the real-time on-line analysis requirement of a high-sensitivity and anti-interference spectral analysis device is met.

The invention discloses a trajectory optimization method of a midcourse guidance with constraints. The trajectory optimization method is used for reducing a shift velocity of a terminal guidance in anintercepting missile. The method comprises the following steps: establishing a kinematic equation of a whole trajectory in a longitudinal plane of the intercepting missile including a trajectory constraint and a terminal constraint, and constructing an intercepting missile trajectory optimization model according to an optimal trajectory of midcourse guidance with constraints set by the method; and optimizing a solution of the trajectory by adopting an hp self-adaptive pseudo-spectral method. According to the method, the shift velocity of the terminal guidance in the intercepting missile can be reduced, a good flight regime of the terminal guidance can be provided and an intercepting precision is improved. And the method is a promising trajectory manner.

The invention relates to a method for processing seismic exploration data in the process of controlling full acoustic wave equation inversion. The method comprises the following steps: acquiring seismic data of a theoretical model to obtain a depth-domain bulk modulus and density initial model; simulating a seismic wave field in an acoustic medium by a pseudo-spectral method; calculating the difference of analog data of the theoretical model and the initial model; giving that delta is equal to 1.0 e-6; calculating error energy E; when E is less than or equal to delta, stopping inversion and outputting the inversion result; if E is more than delta, continuing the following steps; calculating residual error data; calculating the conjugated modification quantity of the bulk modulus and density model; calculating the modified step length to obtain the gradient; modifying the initial model; using the modified model data as a new initial model; carrying out automatic control on the inversion process to make the acoustic wave equation inversion stable, rapid and convergent and improve the inversion convergence speed by nearly five times than a routine method.

Disclosed is a double-pendulum crane global time optimal trajectory planning method based on a pseudo-spectral method. The purpose of automatic control over a nonlinear double-pendulum bridge crane system is achieved. The method has the good functions of trolley positioning and two-stage load pendulum elimination. The method comprises the steps that firstly, a system kinematic model is transformed so as to facilitate following analysis; then, corresponding optimization problems are constructed by considering various constraints including two-stage pendulum angles and trolley speed and acceleration upper limit values; and then, the Gaussian pseudo-spectral method is used for transforming the optimization problems with the constraints into nonlinear programming problems easy to solve to be solved to obtain a trolley trajectory with the optimal time. The thought of the pseudo-spectral method is utilized for handling and transforming the complex time optimal problem, the solving difficulty is lowered; and meanwhile, the result with the optimal global time can be obtained through the method, and the working efficiency of a crane system can be greatly improved. Simulation and experiment results show that the good control effect can be obtained and the good actual application value is achieved.

The embodiment of the application discloses a model transfer method based on spectral data. The method includes measuring indexes of samples and collecting spectra; pretreating the spectra; dividing aplurality of the calibration samples into correction samples and prediction samples; preforming model transfer from a main instrument to a target instrument, namely, forward transfer; and alternatively, performing model transfer from the target instrument to the main instrument, namely, backward transfer. Compared with the traditional method, the method has the following advantages that: the interference of noise and irrelevant information can be suppressed through the correlation between the collected spectral data of the samples and the spectral data structure; two-way model transfer of themain instrument and the target instrument can be realized, and whether the instrument types of the main instrument and the target instrument are consistent or not is unrestricted, and whether collected spectral data points are consistent or not is unrestricted, so that the method is of great significance for model sharing of different types of spectrometers with the same spectral method and improving the applicability of the model.

The invention discloses an initialization method of an elliptical orbit satellite formation configuration under multiple constraints, relates to satellite formation configuration initialization methods, and belongs to the fields of spacecraft guidance and control. The method comprises that an analytical solution is derived from a T-H equation of a real anomaly domain via typical track dynamics andcoordinate transformation, dynamic constraint and periodic fly-around constraint are analyzed, monitoring camera visual field constraint and thrust amplitude constraint are established, a multi-constraint optimal control model of formation is established and solved in a Gaussian pseudo-spectral method, a co-state value in random time is obtained, the completeness of the spacecraft structure is monitored in real time, and the fuel consumption and highest amplitude of a propelling system are reduced by increasing the eccentricity and initialization time. Thus, the elliptical orbit satellite formation configuration can be initialized under multiple constraints, and effective optimal control is realized under the multiple constrains by initialization.

The invention provides a numerical simulation method and device for an earthquake vector wave field. The numerical simulation method comprises the following steps: performing L-times auto-convolution operation on an original window function, thereby acquiring an auto-convolution window function; performing weighted array operation on the auto-convolution window function and the original window function, thereby acquiring an auto-convolution combined window function; cutting off a space convolution sequence of a pseudo-spectral method by the auto-convolution combined window function, thereby acquiring a finite difference operator; performing numerical simulation on the earthquake vector wave field according to the finite difference operator. According to the numerical simulation method provided by the invention, the technical problems of the prior art that the value dispersion of a numerical simulation result of the finite difference earthquake vector wave field is larger and the numerical simulation precision is low because the cutting of the imminent finite difference operator through the window function cannot consider the spectrum coverage area and precision error stability are solved, and the technical effect of effectively increasing the simulation precision of the numerical simulation for the earthquake vector wave field is achieved.

The invention provides a spinning unfolding and folding optimum control method of a dual-body star space tethered formation system. The method includes the steps that first, constraint conditions are determined, wherein the constraint conditions comprise a controlled quantity constraint, a state constraint, a terminal constraint and a dynamics constraint; secondly, performance indexes are selected according to task requirements; afterwards, the optimum control quantity M and the optimum ideal condition are acquired through an hp-self-adaptation pseudo-spectral method; at last, a state error measuring controller and an executing mechanism error controller are designed to control errors of the ideal condition and the optimum control and errors of the virtual condition and practical control respectively. According to the spinning unfolding and folding optimum control method of the dual-body star space tethered formation system, a spinning kinetic model is established based on spinning motion, the dual-body star space tethered formation system can be controlled to complete a spinning unfolding and folding task smoothly under the certain performance indexes and the constraint conditions, and certain theoretical reference is provided for spinning unfolding and folding control of a general dual-body star space tethered formation system.

The invention discloses a path planning optimum control method for a deck of a ship-based aircraft based on an NSP algorithm, and belongs to the technical field of automation and optimum control overship-based aircrafts. Based on analysis of deck path planning of the ship-based aircraft and optimum control over deck path planning, the problem of an original method is solved that path planning andcontrol cannot be combined, and the deficiency is overcome that an obtained path cannot easily meet terminal constraint, and in combination with motion constraint, barrier constraint, control variable and state variable constraint and terminal constraint of sliding of the ship-based aircraft, a path planning optimum control model of the deck of the ship-based aircraft is constructed; based on a Newton iteration method, a symplectic algorithm and a pseudo-spectral method, the NSP algorithm is provided for quickly solving the optimum control model, the problems exist in accurate path planning and control of the deck of the ship-based aircraft are effectively solved, the calculation efficiency and precision are improved, and the obtained path can strictly meet the terminal constraint. According to the path planning optimum control method, a reasonable solution can be provided for the problems existing in path planning and control of the deck of the ship-based aircraft.

The invention relates to a spectral method of color measurement, characterized by that: according to reflectance spectrums of a standard board and a comparative substance, establishing a color parameter database, carrying out data fusion between the collected color feature parameters of the substance to be measured and the color parameter database, and carrying out pattern recognition. According to the invention, a rapid, simple and objective measurement of the color of the substance is provided, the impacts of artificial factors, change of time and space and other uncertainties in the traditional subjective visual method on the accuracy of the measurement are avoided, so that the justice and fairness of the measure result is guaranteed.

Provided by the invention is a piezoelectric ceramic actuator control method based on a particle swarm algorithm. The method comprises: S1, mathematic modeling is carried out on a piezoelectric ceramic actuator by using an electromechanical coupling nonlinear total parameter dynamical model to obtain a dynamical model of the piezoelectric ceramic actuator; S2, on the basis of a pseudo-spectral method, the dynamical model of the piezoelectric ceramic actuator is processed discretely and an optimal control problem is transformed into a nonlinear planning problem; S3, a fitness function of the particle swarm algorithm is obtained based on the nonlinear planning problem; and S4, the fitness function is solved by using the particle swarm algorithm to obtain a global optimal solution. Therefore,the hysteresis characteristic of the piezoelectric ceramic actuator is eliminated and the positioning accuracy of the piezoelectric ceramic actuator is improved.

The invention relates to a clustering-grade satellite fault tolerance control method. A proper and effective satellite formation fault tolerance control strategy is designed for a deep space detectionsystem based on the minimal satellite formation technology, so the formation satellite is capable of adjusting the formation types by use of the nonlinear dynamic planning technology in case of a failure so as to continue to finish task requirements. According to the invention, based on the clustering-grade satellite fault tolerance control method, after the satellite fails in a formation process, by determining initial and termination positions of the fault satellite and a standby satellite, considering inter-satellite collision and time constraints, and taking the fuel consumption as a performance index, by use of the Gauss pseudo-spectral method, the optimal leaving and entering positions of the fault satellite and the standby satellite are determined and respective optimal track plansare acquired, so it is ensured that the position of the fault satellite can be completely filled through the entering the standby satellite, and the standby satellite and the healthy satellites forma new formation, thereby achieving performance requirements of the formation. The method is mainly applied in clustering-grade satellite fault tolerance control occasions.

The invention provides an aluminium alloy hot rolled strip transverse thickness distribution modeling method based on a spectral method. The influence of the thermal coupling effect of rolling force, roll bending force and a temperature field in the rolling process on roller deformation and strip transverse thickness distribution is studied, and a partial differential equation of work roller deformation with a thermal coupling effect is obtained; a characteristic function of a space linear operator corresponding to the equation is chosen as a space primary function, and the spectral method is used for conducting low dimensional approximation modeling to obtain a finite dimension nonlinear ordinary differential equation set; the linear part of the ordinary differential equation set is subjected to dimensionality reduction processing by a balanced truncation method or an optimization method, the nonlinear part and the non-modeled part in the approximate rolling process of a neural network are used for obtaining an intelligent hybrid module with the dimension being very low, and therefore the purpose of quickly forecasting strip transverse thickness distribution is achieved. The aluminium alloy hot rolled strip transverse thickness distribution modeling method based on the spectral method has the advantages that from the aspect of the mechanism of the rolling process, little computing amount is used, the model with the dimension being very low is obtained, accordingly, the real-time performance of forecasting of the strip transverse thickness distribution in the rolling process is improved, and a foundation of system optimization and control system design can be laid.

The invention relates to an acoustic anisotropic reverse-time migration mixing method. A reverse-time migration imaging process is divided into the following steps: 1, setting an observation system and a seismic source location when no seismic data is input to obtain seismic data in anisotropic media, and solving an anisotropic acoustic wave equation by a mixed pseudo-spectral method and an finitedifference method, wherein during application of the finite difference method, high-order rotating staggered grids are adopted to ensure the calculation accuracy and stability, and only one fast Fourier transform is needed at each time step; and 2, applying an improved excitation amplitude imaging condition according to the input seismic data to perform inverse-time migration imaging. The forwardseismic transmission process and the reverse seismic record transmission process are carried out based on the above algorithm, and then reverse-time migration imaging is carried out. The need for computational memory is reduced in a wide range of computational areas. The calculation efficiency of reverse-time migration is improved, seismic acoustic recording is simulated in a large scale of complex anisotropic media, and reverse-time migration imaging is performed.

The invention discloses an anisotropy attenuation surface wave analogy method based on a Chebyshev pseudo-spectral method.The analogy method includes the steps of obtaining shallow geophysical parameter data, a definition observing system and a seismic source function; obtaining a free interface surface wave field updating equation from a wave equation according to free interface vertical and tangential stress conditions; calculating vertical and horizontal derivatives of the free interface surface wave field updating equation by adopting the Chebyshev and Fourier pseudo-spectral method in the vertical and horizontal directions; calculating time differentiation of an anisotropy attenuation medium surface wave equation of the free interface surface wave field updating equation through four-order Runge-Kutta discretization; calculating wave field absorption of two boundaries in the horizontal direction of a model; decomposing the wave equation into an incident wave equation and an emergent wave equation, obtaining a wave field updating equation of the bottom boundaries, and calculating surface waves of the current moment based on the wave field updating equation of the bottom boundaries to generate surface wave shot records and wave field snapshots.The problem of shallow anisotropy attenuation surface wave simulation in the prior art is solved by the anisotropy attenuation surface wave analogy method.

The invention relates to a power system probabilistic state estimation method based on an adaptive sparse pseudo-spectral method, comprising the following steps: (1) building a power system probabilistic state estimation model; and (2) using an adaptive sparse pseudo-spectral method to solve the power system probabilistic state estimation model. The calculation efficiency of power system probabilistic state estimation is improved while it is ensured that various types of measurement uncertainty can be handled and a credible state estimation result can be obtained. The amount of calculation can be determined automatically according to the accuracy requirement. The power system probabilistic state estimation method has the advantages of a wide range of application, high calculation efficiency, high flexibility, and the like.

The invention discloses an optimization method capable of realizing spinning-stabilized unfolding of tethered formation by using a continuous propeller and belongs to the field of spacecraft guidanceand control. The implementation method comprises the steps of defining different reference coordinate systems to describe movement of a tethered formation system and building a dynamical model of thespinning-stabilized tethered formation system by utilizing the Lagrange equation; describing a finite time domain optimal control problem in a real-time domain, then converting the control problem into a Mayer form based on the time domain mapping, giving control input and state variable constraint for the dynamical model of the spinning-stabilized tethered formation system and building an optimalunfolding model of the spinning-stabilized tethered formation system; and scattering the final state of spinning-stabilized unfolding of the tethered formation system and the control input to a series of discrete points by utilizing the Legendre-Gauss discretization method. As numerical solution for the dynamics process of the spinning-stabilized unfolding of the tethered formation system is carried out by using the Gaussian pseudo-spectral method, parameters required to be input can be reduced and the calculation precision is improved.

The invention provides optimal control of a three-degree-of-freedom wave energy converter using a pseudo-spectral control method. The three modes are the heave, pitch and surge. A dynamic model is characterized by a coupling between the pitch and surge modes, while the heave is decoupled. The heave, however, excites the pitch motion through nonlinear parametric excitation in the pitch mode. The invention can use a Fourier series as basis functions to approximate the states and the control. For the parametric excited case, a sequential quadratic programming approach can be implemented to numerically solve for the optimal control. The numerical results show that the harvested energy from three modes is greater than three times the harvested energy from the heave mode alone. Moreover, the harvested energy using a control that accounts for the parametric excitation is significantly higher than the energy harvested when neglecting this nonlinear parametric excitation term.

The invention discloses a method for calculating the electromechanical oscillation mode of a time-delay power system based on an SOD-PS-II-R algorithm. The method comprises the following steps: establishing a time-delay power system model; discretizing the solver of the power system model by a pseudo-spectral method, and obtaining a discretized matrix of the solver of the time-delay power system model; by a coordinate rotation preprocessing method, rotating the discretized matrix of the solver and performing approximating to obtain the discretized approximation matrix of the solver, and calculating the eigenvalues whose modulus values are greater than 1 of the rotated discretized approximation matrix of the solver; by using a sequential method or a subspace method, finding a set number ofeigenvalues having the maximum modulus values of the discretized approximation matrix of the solver from the eigenvalues whose modulus values are greater than 1; and processing the set number of eigenvalues with the maximum modulus values by spectral mapping, coordinate anti-rotation and Newton's check, and finally obtaining an eigenvalue of the time-delay power system model, which corresponds tothe electromechanical oscillation mode of the time-delay power system.

The invention discloses an improved Gauss pseudo-spectral method-based piezoelectric ceramic driver optimum displacement control method. Aiming at influences, on a system of a piezoelectric ceramic driver, of hysteresis linearity of a piezoelectric ceramic driver, control solution is carried out by using an improved Gauss pseudo-spectral method under an electromechanical coupling nonlinear power system model of the piezoelectric ceramic driver, so that a numerical solution of a state variable is obtained; and a Gauss node is changed through judging whether an absolute value of a difference between the numerical value of the state variable and an expected displacement satisfies a practical industrial allowable error or not by combining a requirement of the practical industrial allowable error, so that an optimum displacement with higher precision is obtained. According to the method, the influences, on systems of piezoelectric ceramic drivers are decreased, high-precision numerical solutions are obtained under electromechanical coupling nonlinear power system models of the piezoelectric ceramic drivers, and the positioning precision of the piezoelectric ceramic drivers is improved.

The invention discloses a spectral method for identifying computer software action. The method comprises the steps that (1) a software action representation model is established; (2) software action features are extracted; and (3) software action similarity is measured. The spectral method has the advantages that high-layer soft action features are abstracted from low-layer features which represent software action, software action is described from the semantic layer, a discrete hidden Markov model (DHMM) modeling and spectral factorization method of a computer program is used for representing the software action features of the program quantificationally, and according to the similarity of a representation model and the action features, malicious software is identified.