282 results about "Reduced order" patented technology

A system and a method are provided for performing an integrated uncertainty analysis on a system having interacting modules. The interaction of the modules includes data transfer between the modules with the output of one module being indicative of the input of another module. An uncertainty analysis is performed on each module based on given probability density functions of each input to the module. The uncertainty analysis may include developing a deterministically equivalent model for one or more modules. Data may be provided from one module to another in a uniform format. Thus, two or more modules may be integrated with uncertainties in the inputs of one module being effectively propagated to the inputs of another module. A plurality of modules may thus be modeled as a single integrated system. The integrated system may be replaced with a deterministically equivalent model, preferably of a further reduced order. In this manner, key uncertainties in particular inputs may be isolated. Once these inputs are identified, resources may be effectively allocated to minimize the impact of those inputs on the variability of the results.

A method for modeling changes in the state of charge vs. open circuit voltage (SOC-OCV) curve for a lithium-ion battery cell as it ages. During battery pack charging, voltage and current data are gathered for a battery cell. A set of state equations are used to determine the stoichiometry and state of charge of the cathode half-cell based on the charging current profile over time. The voltage and current data, along with the stoichiometry and state of charge of the cathode half-cell, are then used to estimate maximum and minimum solid concentration values at the anode, using an error function parameter regression / optimization. With stoichiometric conditions at both the cathode and anode calculated, the cell's capacity and a new SOC-OCV curve can be determined.

A computer-aided method suitable for assisting in the design of an aircraft by providing the dimensioning aerodynamic forces and other relevant values comprising the following steps: a) Selecting a set of parameters of the aircraft, being said aerodynamic forces and other relevant values dependant of said parameters; b) Performing flow field CFD RANS computations for a number N1 of different combination of values of said parameters; c) Obtaining said aerodynamic forces and other relevant values for whatever combination of values of said parameters through a reduced-order model, generated by computing the POD modes of the flow variables, expanding the flow variables using said POD modes and obtaining the POD coefficients of said expanded flow variables using a genetic algorithm that minimizes the error associated to the expansion of the Navier-Stokes equations. The invention also refers to a system for carrying out said method.

A rate based model predictive controller for air path control for a diesel engine regulates turbine lift and EGR valve flow rate to specified set points by coordinated control of intake manifold air pressure and EGR valve flow rate. The controller utilizes a rate-based reduced order linear model for model predictive control.

Systems and methods are disclosed for evaluating cardiovascular treatment options for a patient. One method includes creating a three-dimensional model representing a portion of the patient's heart based on patient-specific data regarding a geometry of the patient's heart or vasculature; and for a plurality of treatment options for the patient's heart or vasculature, modifying at least one of the three-dimensional model and a reduced order model based on the three-dimensional model. The method also includes determining, for each of the plurality of treatment options, a value of a blood flow characteristic, by solving at least one of the modified three-dimensional model and the modified reduced order model; and identifying one of the plurality of treatment options that solves a function of at least one of: the determined blood flow characteristics of the patient's heart or vasculature, and one or more costs of each of the plurality of treatment options.

A battery state estimator which combines an electrochemical solid-state concentration model with an empirical equivalent-circuit model. The battery state estimator uses a reduced-order physics-based electrochemical solid-state concentration model to calculate open circuit voltage of a battery cell, and uses the calculated open circuit voltage in an equivalent-circuit model to evaluate a diffusion voltage drop and other battery cell parameters. The battery state estimator is implemented in an online estimator framework using an extended Kalman filter, with a measured terminal voltage and measured current as inputs. A state of charge of the battery cell can be determined from the calculated open circuit voltage, and the state of charge along with the other parameters from the equivalent-circuit model are used to evaluate battery pack performance and to control battery pack charging and discharging.

The invention provides a geometric nonlinear static aeroelasticity analysis method based on a structure reduced-order model. The method includes: building an aircraft wing or full-aircraft finite element model, presetting follow-up test load, and using finite element software to solve corresponding test deformation; under a given nonlinear rigidity coefficient form, performing regression analysison the follow-up test load and the test deformation to solve a nonlinear rigidity coefficient and built the structure reduced-order model; applying the structure reduced-order model to aircraft geometric nonlinear static aeroelasticity analysis, and building aircraft wing geometric nonlinear static aeroelasticity deformation calculation flow and full-aircraft geometric nonlinear static aeroelasticity trim analysis flow. The method has the advantages that the cubic polynomial nonlinear rigidity coefficient is given, an aerodynamic force follow-up effect and extension-direction deformation underaircraft wing geometric nonlinear large deformation are considered, the reasonability and accuracy of geometric nonlinear static aeroelasticity analysis are increased, and efficient analysis and calculation of geometric nonlinear static aeroelasticity deformation and trim are benefited.

The invention provides a hydraulic hard and soft mechanical arm control method based on two-parameter singular perturbation, and relates to the technical field of intelligent machine and robot control. Through the principle of the two-parameter singular perturbation of the method, a reduced order is carried out on a hydraulic hard and soft mechanical arm system to enable the hydraulic hard and soft mechanical arm system to become a fast subsystem driven by representation hydraulic servo, a secondary fast subsystem driven by representation elastic vibration, and a slow subsystem driven by representation wide-range rigid movement, wherein a self-adaptive sliding mode controller is adopted in a fast subsystem control module, an optimal controller is adopted in a secondary fast subsystem control module to restrain the elastic vibration, and a second-order sliding mode controller is adopted in a slow subsystem control module to achieve joint trajectory tracking control. According to the control method based on the two-parameter singular perturbation, the reduced order is carried out on the complex hydraulic hard and soft mechanical arm system, multiple time-scale subsystem controllers are designed, and thus the control method is greatly simplified and is more practical.

The invention relates to the control of trajectory tracking of omni-directional mobile robots. In order to realize the precise control of the omni-directional mobile robot under the condition that theuncertainty of a dynamic model and the external disturbance exist simultaneously, and avoid the inversion operation, the technical solution adopted by the present invention is that: the omni-directional mobile robot trajectory tracking auto-disturbance control method uses an optimized reduced-order extended state observer to estimate the total disturbance of the omnidirectional mobile robot system, including unmodeled parts, parameter uncertainties and external disturbances, and uses a passive controller designed based on passive characteristics of the omnidirectional mobile robot system to compensate the disturbance estimated by the observer to achieve trajectory tracking control; the extended state observer actively takes the disturbance information from the input and output signals ofa controlled object to eliminate interference with control signals before the disturbance affects the system. The invention is mainly applied to the trajectory tracking and control of mobile robots.

A computer-aided method suitable for assisting in the design of an aircraft by providing relevant dimensioning values corresponding to an aircraft component in transonic conditions inside a predefined parameter space by means of a reconstruction of the CFD computations for an initial group of points in the parameter space using a POD reduced-order model, comprising the following steps: a) Decomposing for each flow variable the complete flow field into a smooth field and a shock wave field in each of said computations; b) Obtaining the POD modes associated with the smooth field and the shock wave field considering all said computations; c) Obtaining the POD coefficients using a genetic algorithm (GA) that minimizes a fitness function; d) Calculating said dimensioning values for whatever combination of values of said parameters using the reduced-order model. The invention also refers to a system able to perform the method.

This invention is a ground flutter testing system without a wind tunnel, called Dry Wind Tunnel (DWT) System. The DWT system consists of a Ground Vibration Test (GVT) hardware system, a multiple input multiple output (MIMO) force controller software, and a real-time unsteady aerodynamic force generation software, that is developed from an aerodynamic reduced order model (ROM). The ground flutter test using the DWT System operates on a real structural model, therefore no scaled-down structural model, which is required by the conventional wind tunnel flutter test, is involved. Furthermore, the impact of the structural nonlinearities on the aeroelastic stability can be included automatically. Moreover, the aeroservoelastic characteristics of the aircraft can be easily measured by simply including the flight control system in-the-loop. In addition, the unsteady aerodynamics generated computationally is interference-free from the wind tunnel walls. Finally, the DWT System can be conveniently and inexpensively carried out as a post GVT test with the same hardware, only with some possible rearrangement of the shakers and the inclusion of additional sensors.

A method for mapping moments in a reduced order system of approximation order q for use in simulating a circuit or system having n state variables at n nodes, the circuit or system having I inputs. The method includes calculating only q+I moments, where q is the approximation order and I is the number of inputs of the circuit or system being simulated, sorting the state variables at the n nodes, selecting q nodes of the n nodes, and calculating the dominate poles and zeros using a multi-point moment matching algorithm to simultaneously match q+I moments at the selected q nodes of the circuit or system. In one embodiment, the method includes using extra dummy inputs such that the total number of inputs equals I, such that K*I>q where K is a constant having a value in the range of about 4 to 8.

The invention provides a video human face living body detection method. The method comprises the steps of inputting a video stream; cutting the video stream to obtain N video frame images; establishing N-1 dynamic models for the N video frame images by using a dynamic correlation model algorithm; performing model selection based on phase angle to obtain a final single dynamic reduced-order model image; extracting an LBP uniform pattern feature histogram based on segmentation weighting from the dynamic reduced-order model image; discriminating virtual attack from a legal user based on the SVM classification of three kernel functions. Compared with the prior art, the method uses the dynamic correlation model to pre-treat video frames for the first time, can accurately capture dynamic changes of the human face and better makes up for the blank of lack of living body detection methods with better performance for video attacks in the prior art; the method gives prominence to the human face area of great importance for the living body detection performance. The human face living body detection performance algorithm is generally superior to other conventional methods for video attacks.

Higher Order Ambisonics (HOA) represents a complete sound field in the vicinity of a sweet spot, independent of loudspeaker set-up. The high spatial resolution requires a high number of HOA coefficients. In the invention, dominant sound directions are estimated and the HOA signal representation is decomposed into dominant directional signals in time domain and related direction information, and an ambient component in HOA domain, followed by compression of the ambient component by reducing its order. The reduced-order ambient component is transformed to the spatial domain, and is perceptually coded together with the directional signals. At receiver side, the encoded directional signals and the order-reduced encoded ambient component are perceptually decompressed, the perceptually decompressed ambient signals are transformed to an HOA domain representation of reduced order, followed by order extension. The total HOA representation is re-composed from the directional signals, the corresponding direction information, and the original-order ambient HOA component.

A method for modeling changes in the state of charge vs. open circuit voltage (SOC-OCV) curve for a lithium-ion battery cell as it ages. During battery pack charging, voltage and current data are gathered for a battery cell. A set of state equations are used to determine the stoichiometry and state of charge of the cathode half-cell based on the charging current profile over time. The voltage and current data, along with the stoichiometry and state of charge of the cathode half-cell, are then used to estimate maximum and minimum solid concentration values at the anode, using an error function parameter regression / optimization. With stoichiometric conditions at both the cathode and anode calculated, the cell's capacity and a new SOC-OCV curve can be determined.

The invention relates to a composite layered anti-interference controller, in particular to a design of the composite layered anti-interference controller in a type of multisource jamming control system. The anti-interference controller is designed aiming at the multisource jamming control system containing external model description disturbance, random disturbance and energy-bounded disturbance. Firstly, a reduced-order disturbance observer is structured to estimate and counteract the external model description disturbance of the multisource jamming control system; secondly, the controller having H infinity and guaranteed cost performance index is structured, wherein, the H infinity performance index can be used for inhibiting the energy-bounded disturbance in the system, and the guaranteed cost performance index can be used for inhibiting the random disturbance in the system as well as optimizing the upper bound of variance; the composite layered anti-interference controller can be formed by the reduced-order disturbance observer and the feedback controller with a state of robust H infinity and guaranteed cost; finally, based on convex optimization algorithm, gain array of the composite layered anti-interference controller can be solved. The invention has the advantages of strong anti-interference property, convenient design and the like, and can be applied to a navigation and control system of aerospaceplane, etc.

The invention is principally directed to a reduced order model, XEDOR, facilitating the prediction of and the diagnostics of pellet-clad interaction stress-corrosion-cracking failure of nuclear fuel rods. The invention more particularly relates to assessment of susceptibility to PCI failure for guidance in the design of fuel loading in nuclear reactors. The invention additionally relates to the protection against PCI failure by providing operational information to operators of a nuclear reactor during power maneuvering, including predictive calculations prior to executing power maneuvers. Additionally, the invention relates to the diagnostics of an event suggesting a possible PCI cladding failure.

The invention discloses an adaptive segmentation multistage linear spectrum generalized standard control missdistance reentry guidance method. The guidance method is applied to a high-lift-drag-ratio reentry aircraft and can satisfy multiple terminal constraints and process constraints. The method combines basic ideas of nonlinear model prediction control, a multistage linear pseudo spectrum method and calculus of variations, is greatly different from a Yu method in that a processing object is reduced-order nonlinear reentry dynamics taking a coupling effect into consideration, and also takes terminal heights and trajectory inclination angle constraints into consideration apart from considering a terminal position requirement and a roll angle requirement.

The invention relates to in an analysis method of the Facial Expression image classification and semantic evaluation on the basis of semantic evaluation and the quantization. This invention makes use of the sample collection of training Facial Expression images, extracting expression characteristics to form a marker map of LG Vector, projecting it to the Principal Component PCA subspace, making the use of these reduced-order LG Vectors to learn mixed multi-dimensional t-distribution, as the semantic judgment of six basic emotions of the images, in according to that which probability taken up by expression is maximal, that image is judged thereby to that expression. Which resolve the recognition difficulties of the uncertainties, automatic facial expression existed in the current technology, and the singularity difficult to overcome such defect. This invention is an extremely flexible and powerful modeling tools based on the statistics, provides a more robust ways, avoiding the extreme estimates of posterior probability of the subordinate component of sample observed, the training samples do not require labeling, do not require any post-processing, less sensitive to outliers, avoid this artificial Judgment.

A processing unit of an analysis system comprises a processor coupled to a memory, and is configured to generate a structure-preserving reduced-order model of a circuit, device or system. The reduced-order model in one embodiment is generated by projection of input matrices characterizing the circuit, device or system onto at least one block Krylov subspace, the block Krylov subspace having a corresponding basis matrix. The projection utilizes at least one matrix that has a column range which includes a corresponding portion of the block Krylov subspace but is not itself the basis matrix of the block Krylov subspace. The processing unit generates a frequency response or other signal characterizing the circuit, device or system, based at least in part on the reduced-order model, and an associated output unit presents the generated signal in a user-perceptible format.

The invention discloses a multichannel direct current added damping control device capable of simultaneously restraining sub-synchronization and low frequency oscillation, and a parameter setting method of the multichannel direct current added damping control device. The device is characterized in that the device identifies the subsynchronous oscillation, the low frequency oscilation frequency and the damping of a direct current under island running and a system reduced-order model on the basis of a matrix pencil algorithm which has high operation efficiency and anti-interference capacity, a multichannel direct current added damping controller is designed through a root locus method so as to reduce mutual effects between oscillation modes, and sub-synchronization and low frequency oscillation can be simultaneously restrained. Electric generator rotating speed signals are divided into multiple frequency bands according to results of analysis conducted on characteristics of system oscillation through the matrix pencil algorithm, a passageway corresponding to each frequency band can independently adjust the gain, the phase position, the output amplitude limit and the filter parameters, and therefore appropriate damping can be provided for sub-synchronization and low frequency oscillation in different frequency bands. The device is efficient and easy to obtain, and the function of simultaneously restraining sub-synchronization and low frequency oscillation through the direct current added damping controller is achieved for the first time in the high voltage direct current transmission field.

The invention relates to an asymptotic variational method-based method for simulating and optimizing a composite material laminated plate, which belongs to the field of analysis of material mechanics. The method specifically comprises the following steps of: constructing a three-dimensional plate energy equation represented by a one-dimensional generalized strain and warping function on the basisof a rotation tensor decomposition concept; strictly splitting the original three-dimensional problem analysis into nonlinear two-dimensional plate analysis and cross-section analysis along a thickness direction on the basis of an asymptotic variational method; asymptotically correcting an approximate energy functional of a reduced-order model to a second order by using the inherent small parameter of the plate and converting the approximate energy functional into the form of Reissner model for practical application through an equilibrium equation; accurately reconstructing a three-dimensional stress / strain / displacement field by using an obtained global response asymptotic correction warping function; and optimizing the composite material laminated plate by using an optimization strategy of bending and torsion rigidity coefficients obtained by maximization cross-section analysis. The method has high practicability and high generality, and the resolving speed and efficiency of this type of problems can be remarkably increased.

Within a receiver, a channel estimation mechanism involves a hardware interpolator. In a first mode, narrowband pilot values are analyzed to generate channel parameters that are supplied to the interpolator such that the interpolator generates channel estimate values. The channel estimate values are used to demodulate a tile of a frame. In a second mode, broadband pilot values are supplied to an IFFT, thereby generating time domain values. After time domain processing, an FFT is employed to generate intermediate channel estimate values. These intermediate values are analyzed to determine channel parameters, which in turn are supplied to the hardware interpolator so that the interpolator generates a larger number of channel estimate values. After phase adjustment, the channel estimate values are used in demodulation. Use of the interpolator in the broadband mode allows the FFT employed to be of a smaller order, and to consume less power and / or processing resources.

The invention discloses an aircraft flutter prediction and analysis method and device. The method comprises the following steps: applying an input signal through an exciting point on an aircraft structure, and receiving an output signal through a collection point which is configured on the aircraft structure; establishing a nonlinear kinetic model of the aircraft structure by utilizing a nonlinear system recognition algorithm according to the input signal and the output signal; establishing an unsteady aerodynamic model on the basis of the calculation fluid kinetic technology; performing reduced order for the unsteady aerodynamic model according to the nonlinear kinetic model of the aircraft structure to obtain a reduced order model; performing the fluid-structure interaction analysis on the nonlinear kinetic model and the reduced order model so as to make the flutter prediction and analysis on the corresponding aircraft structure. Since the nonlinear kinetic model of the aircraft structure is acquired by performing the test according to the real aircraft structure, the accuracy in flutter prediction and analysis can be improved.

The invention provides a maneuvering target ISAR (Inverse Synthetic Aperture Radar) imaging method utilizing compressed sensing. The method comprises the following steps: obtaining ISAR return wave data, and allowing the return wave data to be subjected to distance compression, motion compensation and migration correction so as to obtain a complex matrix Sd; generating a Gaussian random matrix Phi, and allowing the Sd to be subjected to reduced-order observation so as to obtain a matrix Y; obtaining a sparse basis matrix of ISAR to-be-imaged times ti; solving each column of the matrix Y through a 1-norm convex optimization equation so as to obtain ISAR image results of times ti; and traversing all imaging times, so as to realize the ISAR imaging of a maneuvering target at all periods. The imaging method lowers the requirement on imaging return wave sampling rate, realizes free imaging of the maneuvering target at all imaging times, and improves no only the azimuth imaging effect of the maneuvering target, but also the ISAR imaging quality.

The invention discloses a fault-tolerant control method for a two-phase open-circuit fault of a five-phase permanent magnet synchronous motor based on SVPWM (Space Vector Pulse Width Modulation), which comprises the step that the algorithm calculates to obtain a corresponding voltage space vector through constructing a reduced-order matrix after the fault. The synthesis of a reference vector is realized by the division of six sectors and the reconstruction of six non-zero voltage vectors. The fault-tolerant control method is similar to the control of a three-phase motor under normal working conditions, is simple to calculate and easy to implement. The fault-tolerant control method can greatly reduce the torque ripple caused by an open-circuit fault of a stator winding while ensuring the average torque, enables the five-phase PMSM (Permanent Magnet Synchronous Motor) to be obviously improved in operation performance under the fault state, and effectively improves the reliability of a speed regulation system. Simulation and experimental results show that high-quality operation of a five-phase motor driving system under the two-phase open-circuit fault can be realized by adopting thefault-tolerant control strategy.

The invention discloses a high-voltage direct-current power transmission multi-channel supplementary damping control method based on a variable structure. The high-voltage direct-current power transmission multi-channel supplementary damping control method has the characteristics that sub-synchronous and low frequency oscillation frequencies and damps, and a system reduced-order model are identified by a TLS-ESPRIT (Total Least Squares-Estimation of Signal Parameters via Rotational Invariance Techniques) algorithm with high operation efficiency and anti-interference capability; a variable structure control principle is combined and an attached controller containing a virtual state variable is designed; finally, a state observer is led in to eliminate the virtual state variable so as to realize an HVDC (High Voltage Direct Current) variable structure controller with an output feedback form; then a variable structure control theory is used for designing a multi-channel direct-current attached damping controller so as to reduce the mutual influences between oscillation modes; the sub-synchronous and low frequency oscillation can be inhibited synchronously. The method is efficient and feasible; the variable structure control theory has strong disturbance rejection on complicated changeable working conditions of an actual power grid; meanwhile, a multi-channel structure is utilized by using the controller to solve a coordinated control problem among the plurality of controllers; the invention provides a controller design method of an actual large power grid with very strong operability.

The invention discloses a fault-tolerant dual-vector prediction control method and apparatus for a six-phase permanent magnet motor. The fault-tolerant dual-vector prediction control method comprisesthe steps of obtaining the rotor position, rotary speed and phase current of the six-phase motor; solving fault phase counter electromotive force according to the rotor position, the rotary speed, thepermanent magnet flux linkage on the rotor and the axial line position of the fault phase, and establishing a motor frequency converter model by considering the fault phase counter electromotive force; establishing a reduced-order motor mathematical model according to the position of the fault phase; establishing a six-phase motor switch meter after fault, obtaining phase voltages corresponding to respective switch vectors, bringing in the reduced-order motor mathematical model, and determining a phase current prediction value of each switch vector after one sampling period is executed; performing evaluation on error between each phase current prediction value of each switch vector and the corresponding phase current instruction value, and selecting the switch vector with the minimum error as the optimal switch vector; and performing modulation on the optimal switch vector and a zero vector in one sampling period to determine the duty ratio of the optimal switch vector. By virtue of the fault-tolerant dual-vector prediction control method, the current harmonic of the faulty motor can be suppressed effectively.

A method comprising a computational procedure for obtaining reduced-order models of partial element equivalent circuit (PEEC) models of very large scale integrated (VLSI) interconnects. The methodology is not limited to PEEC applications, and can be used for generating reduced-order models of other systems which can be modeled with linear, time-invariant systems of ordinary differential equations with time delays.