27 results about "Time-variant system" patented technology

The invention discloses a rapid calculation method and device for the sensitivity of a linear periodic time-varying system based on a matrix sparse technology, and belongs to the technical field of modeling analysis of the linear periodic time-varying system.The rapid calculation method comprises the steps that an LTP system is converted into an equivalent LTI system, and the eigenvalue, the left eigenvector and the right eigenvector of the LTP system are obtained; based on a functional derivative method, obtaining a sensitivity analytical expression of the LTP system characteristic value to the parameter; according to the influence mechanism of the parameters on the system matrix, obtaining an analysis form of the influence of the parameters on the LTP system matrix in the sensitivity analysis expression; and converting a partial derivative of a system matrix to a steady-state trajectory into sparse calculation of a vector field Hessian matrix by using a matrix sparse technology, thereby obtaining a calculation result of the characteristic value sensitivity of the LTP system. According to the method, the sparse characteristic of the system matrix in the PEPS is utilized, the calculated amount and the storage requirement of the system matrix on trajectory partial derivative solving are reduced, and therefore calculation of the LTP characteristic value sensitivity is accelerated.

The invention discloses a parameter time-varying characteristic considered LTP system characteristic value sensitivity analysis method for power system stability analysis, and belongs to the field of linear period time-varying system analysis control. According to the method, the influence relation of the change of a time-varying parameter alpha (t) on a dominant characteristic value lambda i is analyzed by utilizing the partial derivative of the dominant characteristic value lambda i of the power system to the time-varying parameter alpha (t), and the size and direction of the influence of the change of the time-varying parameter alpha (t) on the dominant characteristic value lambda i are quantified according to the actual time-varying parameter change. Analyzing and depicting the influence degree of changes of time-varying operation parameters, time-varying control parameters and the like on characteristic values in the power system, so as to realize stable analysis and control of planning, scheduling optimization, parameter optimization, controller design and the like of the power system; wherein the functional relationship between the LTP system matrix and the time-varying parameter is considered, and the functional derivative of the system matrix to the time-varying parameter is adopted to represent the partial derivative of the system matrix to the time-varying parameter.

The invention belongs to the technical field of linear system dynamics analysis and control, and particularly discloses a linear period time-varying system output feedback stabilization control design method and device, and the method comprises the steps: obtaining a state transition matrix through a numerical calculation method based on a linear period time-varying system; based on the state transition matrix and a preset new input variable, obtaining a transformed input variable, a transformed output variable and a discrete linear time-invariant system; designing an observer and a state feedback control law based on the discrete linear time-invariant system, the preset new input variable and the transformed output variable; and constructing output feedback stabilization control of the linear period time-varying system based on the transformed input variable, the transformed output variable, the observer, the state feedback control law and the preset new input variable. According to the method, system stabilization can be effectively achieved, strict mathematical conditions and hypotheses do not need to be introduced for solving, the application range is wider, and the method can be applied to a generalized linear period time-varying system.

The invention discloses a self-tuning delay method and system for suspension load vibration control, and relates to the field of mechanical structure vibration control. According to the method, a parameter observation function is introduced into a self-tuning delay control algorithm, so that the delay parameter can be adaptively adjusted in real time according to the changing rope length, and the control algorithm can still keep robust and effective vibration suppression performance under the condition that the system parameter (such as the rope length) is continuously changed; the problem of performance degradation of a traditional control method in a time-varying system is solved; in the core time lag parameter design of the self-tuning time lag control algorithm, the inherent closed-loop time lag of the system is directly integrated, and the use of a traditional time lag compensator (such as a Smith predictor and model predictive control) which is complicated and depends on a high-precision model is avoided, so that a control loop is basically not influenced by the system feedback time lag, and the control precision is improved. And an effective and simple solution is provided.

The invention discloses a modal frequency quantification method of a linear periodic time-varying system for stability analysis of a power system, and belongs to the technical field of system stability analysis. According to the method, the modal frequency of the linear period time-varying system is analyzed based on the Floquet theory, the technical defect that a classical modal frequency analysis method is only suitable for a linear time-invariant system is overcome, and theoretical support is provided for carrying out modal frequency analysis on the linear period time-varying system. The linear period time-varying system modal frequency analysis method provided by the invention can accurately evaluate the oscillation frequency of the potential oscillation risk of the system under different working conditions, and can accurately quantify the oscillation frequency range when the system has an oscillation accident.

The invention discloses a data driving control method based on a sliding window and feature point selection in a time-varying scene, and relates to the technical field of adaptive control of data driving, and the method comprises the steps: collecting input and output signals of a time-varying system in real time through a sensor; dynamically updating an input / output track data structure based on a sliding window mechanism to ensure that the data structure always reflects the current dynamic characteristics of the system; feature point selection is carried out on the trajectory data structure through singular value decomposition, data information is quantized, dimension reduction processing is carried out, and a dimension reduction data structure is generated; constructing a control optimization objective function based on the dimension reduction data structure, solving a decision variable and generating a control instruction; and balancing the data structure dimension and the information completeness through an adaptive order adjustment mechanism. According to the method, the data is updated in real time through a sliding window mechanism, and the data dimension is selected and optimized based on the feature points of singular value decomposition, so that the timeliness, the calculation efficiency and the control precision of time-varying system data driving control are remarkably improved.

The present invention discloses a fractional-order circuit control method and system based on a full-drive model, which relates to the field of tracking control technology, constructs a fractional-order generalized model of a fractional-order circuit; performs equivalent decomposition on the fractional-order generalized model to obtain a fractional-order full-drive model, and constructs the output of the fractional-order full-drive model; constructs a control model based on the output and the fractional-order full-drive model; constructs a compensation model based on the output and a set target value; constructs an augmented model based on the compensation model, the control model, the output and the fractional-order full-drive model; constructs the feedback part of the control model; substitutes the feedback part into the augmented model to obtain a state matrix of the fractional-order circuit; solves the state matrix to obtain the control parameters of the control model. The present invention transforms the modeled fractional-order generalized time-varying system into a fractional-order full-drive model with equality constraints, designs an output tracking controller based on the model, provides a controller parameter solving method, and is suitable for fractional-order nonlinear time-varying circuits.

The invention belongs to the technical field of linear system dynamics analysis, and particularly discloses a controllable and observable quantitative analysis method and device for a linear period time-varying system mode. According to the method, the solution of the state variable of the system under multiple groups of initial values is solved through a numerical calculation method, so that the state transition matrix is obtained more accurately. The eigenvalue and the eigenvector of the state transition matrix correspond to the oscillation mode of the system, and the incidence relation between the input / output and the oscillation mode is established by solving the eigenvalue and the eigenvector. By calculating the mode controllability and the mode observability of the linear period time-varying system, the incidence relation between the input / output of the linear period time-varying system and the oscillation mode is accurately quantified, and a dynamic stability analysis theory system of the linear period time-varying system is further improved; the method is of great significance to stability mechanism analysis, stability rule description and the like of a large-scale linear periodic time-varying system, and theoretical support is provided for design and implementation of stabilization control of the linear periodic time-varying system.

The embodiments are directed to an inferential sensing system, methods and computer program product of an estimator for estimating parameters of complex nonlinear time-varying systems from scarce system output measurements. The estimator comprises a two-step process to accurately estimate the time-varying parameters of the time-varying system based on the input and output sample of the time-varying system. First, multiple filters in the high frequency processing loop, operating independently and concurrently process the input and output samples of the time-varying system to generate a hypersurface comprising time series objects. Each filter is restricted to adapt only a subset of the modeled time-varying parameters. The hypersurface comprising the time series objects is aggregated over several iterations of the high frequency processing loop. Second, the hypersurface is passed through a neural network in the low frequency processing loop to infer estimates of the time-varying system parameters.

The application discloses a kind of four-rotor hanging transport control methods based on double time-varying interference estimator, comprising the following steps: S1, the dynamics model of four-rotor unmanned aerial vehicle and hanging load is established;S2, the model is simplified using feedback linearization technique, and the nonlinear coupling system is decoupled into two subsystems of anti-swing and trajectory tracking;S3, according to the swing model of the goods being hung, time-varying uncertainty and interference estimator are constructed in the anti-swing controller, and time-varying interference is dynamically aggregated to eliminate the swing of heavy object;S4, according to the kinematics model of four-rotor, time-varying uncertainty and interference estimator are constructed in the trajectory tracking controller, to realize the accurate trajectory tracking of four-rotor unmanned aerial vehicle;S5, the stability of estimation error system is proved using linear time-varying system theory, and the interference estimation performance is optimized by adjusting auxiliary parameter;S6, the stability of anti-swing subsystem and trajectory tracking subsystem is proved, and the interference estimation performance is optimized by adjusting auxiliary parameter.

This invention relates to a method and system for estimating the reachability set of periodic time-varying mechanical systems based on set intersection. The method includes: establishing a state-space model of the periodic time-varying system; identifying and representing its periodic matrix as a sum of periodic time-varying terms; constructing a Lyapunov function based on linear piecewise division to obtain a time-varying criterion for reachability set estimation; constructing a multi-affine time-varying matrix polynomial; determining the convex constraints for reachability set estimation based on the properties of multi-affine, and designing an optimization function to obtain a constrained optimization problem to obtain the reachability set boundary; obtaining the optimal decay parameter through simulated annealing iterative optimization; selecting multiple decay parameters around the optimal decay parameter to obtain different boundaries, and generating a new reachability set boundary by taking the intersection of these parameters, and quantitatively calculating the degree of conservatism reduction of the new reachability set boundary. This invention can be used to estimate the reachability set of periodic time-varying mechanical systems, reduce the conservatism of reachability set estimation, and quantitatively evaluate the degree of conservatism reduction.

The embodiments are directed to an inferential sensing system, methods and computer program product of an estimator for estimating parameters of complex nonlinear time-varying systems from scarce system output measurements. The estimator comprises a two-step process to accurately estimate the time-varying parameters of the time-varying system based on the input and output sample of the time-varying system. First, multiple filters in the high frequency processing loop, operating independently and concurrently process the input and output samples of the time-varying system to generate a hypersurface comprising time series objects. Each filter is restricted to adapt only a subset of the modeled time-varying parameters. The hypersurface comprising the time series objects is aggregated over several iterations of the high frequency processing loop. Second, the hypersurface is passed through a neural network in the low frequency processing loop to infer estimates of the time-varying system parameters.

A composite control method for a time-varying system of a hypersonic interceptor missile, which belongs to the technical field of interceptor missile control. The present invention solves the problem of low execution efficiency of the control system of the time-varying system of the hypersonic interceptor missile caused by only using aerodynamic rudders. In view of the problem that the aerodynamic parameters of the hypersonic interceptor missile change with time during the actual flight process, the present invention applies the LQR and sliding mode methods to the time-varying control system of the interceptor missile. Among them, a controller for the aerodynamic force time-varying system is designed based on the LQR method, and the phase transformation method is used to design a sliding mode controller for the direct lateral force time-varying system, jointly realizing the direct / aerodynamic composite control of the interceptor missile. The method of the present invention can be applied to the control of the time-varying system of the hypersonic interceptor missile.

The invention discloses a linear periodic time-varying system stability judgment method and system based on a harmonic state space model and a medium, and belongs to the field of linear system dynamics analysis, and the method comprises the steps: respectively constructing harmonic state space models MH and ML with a high truncation order H and a low truncation order L for the system; calculating a first characteristic value and a first characteristic vector of ML; for the MH, arranging state variables of the MH according to the sequence of # imgabs0 # so as to transform the MH; calculating the deviation of the system matrix of the ML under the first characteristic value relative to the system matrix of the transformed MH to obtain a deviation matrix; calculating a characteristic value deviation according to the deviation matrix and the first characteristic vector, and calculating the sum of the characteristic value deviation and the first characteristic value to obtain a second characteristic value of the MH; and determining the stability of the linear period time-varying system according to the second characteristic value. The calculation efficiency is improved while the characteristic value calculation accuracy is ensured, and the applicability of the harmonic state space model to a large-scale system is enhanced.

This invention proposes a method and system for obtaining the trajectory of a periodic time-varying system based on Chebyshev placement, belonging to the field of power electronics technology. The method includes: establishing a periodic boundary value problem model of the periodic time-varying system, determining the system period and the number of placement points; performing time-scale mapping on a single-period interval, selecting Chebyshev placement points and constructing a spectral differential matrix; applying system dynamic constraints at each placement point, discretizing the differential equations into a system of nonlinear implicit algebraic equations; introducing periodic closure constraints to form a closed nonlinear algebraic equation system; and using an internal and external iterative strategy to solve the closed equation system, outputting the steady-state periodic discrete trajectory. This invention, by placing Chebyshev points within a single-period interval and constructing a spectral differential matrix, directly transforms the differential equations into a system of algebraic equations, avoiding long time-domain integration, and possesses advantages such as high computational efficiency, fast convergence speed, good numerical stability, and strong engineering feasibility.

The present invention discloses a method for quickly solving MMC harmonic power flow, which belongs to the field of direct current transmission. Aiming at the shortcoming that the time domain simulation method is difficult to conveniently solve the harmonic power flow, the present invention firstly establishes a complete MMC harmonic state space model taking into account the control links such as the V / F control outer loop, the current inner loop, the grid voltage feedforward loop, and the circulating current suppression loop based on the harmonic state space theory. Subsequently, aiming at the shortcoming that the time for solving the steady-state power flow in the time domain simulation is too long, based on the characteristics of the periodic time-varying system in the frequency domain, the present invention proposes a frequency shift factor, which can greatly reduce the dimension of the MCC model and speed up the iterative solution speed of the harmonic power flow.

The embodiments are directed to an inferential sensing system, methods and computer program product of an estimator for estimating parameters of complex nonlinear time-varying systems from scarce system output measurements. The estimator comprises a two-step process to accurately estimate the time-varying parameters of the time-varying system based on the input and output sample of the time-varying system. First, multiple filters in the high frequency processing loop, operating independently and concurrently process the input and output samples of the time-varying system to generate a hypersurface comprising time series objects. Each filter is restricted to adapt only a subset of the modeled time-varying parameters. The hypersurface comprising the time series objects is aggregated over several iterations of the high frequency processing loop. Second, the hypersurface is passed through a neural network in the low frequency processing loop to infer estimates of the time-varying system parameters.

The application discloses a dynamic stability analysis control method, device and system of a linear periodic time-varying system, and belongs to the technical field of system stability analysis. i The partial derivative of the concerned parameter alpha with respect to the dominant eigenvalue lambda i The sensitivity of the concerned variable alpha to the dominant eigenvalue of the linear periodic time-varying system is analyzed, the influence size and direction of the system control concerned parameter on the dominant eigenvalue can be accurately described, the technical defects that the classical dominant eigenvalue sensitivity analysis method is only applicable to linear time-invariant systems are made up, and theoretical support is provided for the dominant eigenvalue sensitivity analysis of the linear periodic time-varying system. In addition, the system matrix with complex time-varying characteristics does not need to be time-invariant, and the operation is simpler.

The invention discloses a left feature vector calculation method, system and device suitable for an LTP system, and a storage medium. The method comprises the following steps: deducing based on a Floquet theory to obtain a time domain expression of a left feature vector of a linear periodic time-varying system; converting the left feature vector of the linear periodic time-varying system of the time domain into a frequency domain, and establishing a relation between the left feature vector of the linear periodic time-varying system of the frequency domain and the left feature vector of the harmonic state space; calculating a harmonic state space left feature vector, and converting the harmonic state space left feature vector to a time domain to obtain a time domain linear periodic time-varying system left feature vector; the method does not need to depend on the inversion of the ill-conditioned STM, avoids the demand of the inversion of the ill-conditioned STM, obtains the more reliable LTP left feature vector through calculation, can improve the solving reliability of the LTP left feature vector, and lays a foundation for the modal analysis of an LTP system.

The invention discloses a parameter-adaptive spatial mass block motion state acquisition method and system. The method comprises the following steps: constructing a linear random time-varying system for a motion state equation of mass block motion; obtaining a time-varying coefficient matrix and a time-varying disturbance input matrix; constructing a parameter-adaptive time-varying Runge-Kutta solver, and obtaining a to-be-determined parameter list of the Runge-Kutta solver; according to a self-adaptive parameter constraint formula, the dependency relationship of all parameters in the parameter list is solved, free parameters and other parameters are determined, and the free parameters are optimized and iteratively updated by adopting an optimization algorithm in a mode of comparing with an analytic solution until optimal free parameter selection is obtained. The method can be widely applied to high-precision satellite state acquisition of space science and technology. The method is not only suitable for acquiring the motion state of the mass block in a single scientific satellite, but also suitable for acquiring the motion state of a plurality of mass blocks running in a formation.

The present invention relates to the technical field of state estimation and fault detection, solves the technical problem that traditional closed-loop fault diagnosis methods cannot effectively decouple control signals and residual signals, and particularly relates to a fault detection method for an uncertain stochastic time-varying system considering output feedback control, including: theoretically modeling using a linear discrete system with model uncertainty to obtain the dynamic mathematical model of the linear discrete system; constructing a closed-loop residual generator based on the dynamic mathematical model for generating residual signals reflecting the system state; designing a fault detection threshold; analyzing the fault detectability, and verifying that the linear discrete system can be effectively identified and located when a fault occurs. The present invention realizes the effective detection and diagnosis of system faults under the condition of norm-bounded model uncertainty, and ensures the minimization of the upper bound of the estimation error variance for each step of recursive calculation, thereby providing a reliable and efficient technical solution for fault diagnosis.

The invention relates to the technical field of state estimation and fault detection, solves the technical problem that a traditional closed-loop fault diagnosis method cannot effectively decouple a control signal and a residual signal, and particularly relates to an uncertain random time-varying system fault detection method considering output feedback control. Comprising the following steps: carrying out theoretical modeling by adopting a linear discrete system with model uncertainty to obtain a dynamic mathematical model of the linear discrete system; constructing a closed-loop residual generator used for generating a residual signal reflecting a system state based on the dynamic mathematical model; designing a fault detection threshold value; and analyzing the fault detectability, and verifying that the linear discrete system can be effectively identified and positioned when the fault occurs. According to the method, effective detection and diagnosis of the system fault are realized under the condition of uncertainty of the norm bounded model, and minimization of the upper bound of the estimation error variance of each step of recursion calculation is ensured, so that a reliable and efficient fault diagnosis technical solution is provided.

The invention discloses a state transition method in deductable time-varying system simulation, and belongs to the technical field of deductable continuous system simulation. Comprising the following steps: step 1, constructing an assembly line model, and establishing a mapping relation between the position and state of a research object through the assembly line model; 2, state prediction of a research object is achieved according to the mapping relation of the pipeline model; and realizing state transition according to state prediction. The method for deducing state transition in time-varying system simulation has the advantages of being low in research and application cost and high in stability.

The invention discloses a four-rotor hanging transportation control method based on double time-varying interference estimators. The method comprises the following steps: S1, establishing a kinetic model of a four-rotor unmanned aerial vehicle and a hanging load; s2, simplifying the model by using a feedback linearization technology, and decoupling a nonlinear coupling system into an anti-swing subsystem and a trajectory tracking subsystem; s3, constructing a time-varying uncertainty and interference estimator in the anti-swing controller according to the swing model of the lifted cargo, and dynamically aggregating time-varying interference to eliminate swing of the heavy object; s4, constructing a time-varying uncertainty and interference estimator in a trajectory tracking controller according to the four-rotor kinematics model, and realizing accurate trajectory tracking of the four-rotor unmanned aerial vehicle; s5, proving the stability of an estimation error system by using a linear time-varying system theory, and optimizing the interference estimation performance by adjusting auxiliary parameters; and S6, the stability of the anti-swing subsystem and the trajectory tracking subsystem is proved, and the interference estimation performance is optimized by adjusting auxiliary parameters.

The invention discloses a digital time-varying convolution method for time-varying system analysis. The digital time-varying convolution method comprises the following steps: setting an estimated state according to application requirements; according to different pre-estimation states, pre-processing an input signal to obtain a digital input sequence; finding a sampling moment index value corresponding to an adjacent time-varying stage of any input moment index n; calculating a real-time time-varying coefficient at the nth moment according to the sampling moment index value of the adjacent time-varying stage at the nth moment and the corresponding stage time-varying coefficient; and calculating a time-varying system output value at the nth moment according to the real-time time-varying coefficient at the nth moment. The calculated time-varying coefficient and the time-varying coefficient of the adjacent different time-varying stages have a continuous change relation in time, and the obtained output result also has good continuity and is more in line with the response result of a real time-varying system.

The application belongs to the technical field of system analysis, and discloses a participation factor analysis method and device suitable for a piecewise linear periodic time-varying system, which comprises the following steps: reconstructing a nonlinear periodic time-varying system with switching behavior into a piecewise linear periodic time-varying system, solving the eigenvalues, and solving the eigenvectors based on the eigenvalues; when solving the eigenvectors, the eigenvectors of the current continuous interval are solved first, then the end eigenvectors of the current continuous interval are made to pass through the switching time based on the jump matrix to obtain the eigenvectors at the start of the next continuous interval, the eigenvectors of the next continuous interval are solved, and the above steps are sequentially repeated until the eigenvectors in one period are obtained, and then the participation factors are calculated through integration. The above analysis method can accurately calculate the participation factors of the piecewise linear periodic time-varying system, and the obtained participation factors can be used to analyze the deep reasons for system instability.

The invention discloses a method for rapidly solving harmonic power flow of an MMC (Modular Multilevel Converter), belongs to the field of direct-current power transmission, and aims to overcome the defect that the harmonic power flow is difficult to solve conveniently by a time domain simulation method. A complete MMC harmonic state space model considering control links such as a V / F control outer loop, a current inner loop, a power grid voltage feed-forward loop and a circulating current suppression loop is established. And then aiming at the defect that the time for solving the steady-state power flow is too long in time domain simulation, the invention provides a frequency shift factor based on the characteristics of a periodic time-varying system in a frequency domain, so that the dimensionality of an MCC model can be greatly reduced, and the iterative solving speed of the harmonic power flow is accelerated.