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247 results about "Order reduction" patented technology

System and methodology and adaptive, linear model predictive control based on rigorous, nonlinear process model

A methodology for process modeling and control and the software system implementation of this methodology, which includes a rigorous, nonlinear process simulation model, the generation of appropriate linear models derived from the rigorous model, and an adaptive, linear model predictive controller (MPC) that utilizes the derived linear models. A state space, multivariable, model predictive controller (MPC) is the preferred choice for the MPC since the nonlinear simulation model is analytically translated into a set of linear state equations and thus simplifies the translation of the linearized simulation equations to the modeling format required by the controller. Various other MPC modeling forms such as transfer functions, impulse response coefficients, and step response coefficients may also be used. The methodology is very general in that any model predictive controller using one of the above modeling forms can be used as the controller. The methodology also includes various modules that improve reliability and performance. For example, there is a data pretreatment module used to pre-process the plant measurements for gross error detection. A data reconciliation and parameter estimation module is then used to correct for instrumentation errors and to adjust model parameters based on current operating conditions. The full-order state space model can be reduced by the order reduction module to obtain fewer states for the controller model. Automated MPC tuning is also provided to improve control performance.
Owner:ABB AUTOMATION INC

Satellite in-orbit micro-vibration simulation modeling correction method

ActiveCN103488812AReduce micro-vibration interferenceHigh precisionSpecial data processing applicationsElement modelAttitude control
The invention provides a satellite in-orbit micro-vibration simulation modeling correction method, which comprises the following steps of: analyzing satellite configuration to separately model a satellite body structure and an on-satellite rotating part; according to ground test data and a finite element principle, carrying out modeling of a satellite body structure finite element model; according to attitude control and ground micro-vibration test data of other on-satellite rotating parts, establishing an on-satellite rotating part simulation model; according to a ground test state, establishing a ground simulation model, deleting ground constraints and establishing an in-orbit micro-vibration simulation model; according to the ground test data, a moving part, a control mode of the moving part and a modal value order reduction method, correcting the in-orbit micro-vibration simulation model; carrying out micro-vibration simulation analysis on the ground test state and utilizing the ground micro-vibration test data to carry out model correction; and deleting the corrected model ground constraint conditions to complete modeling. According to the invention, micro-vibration interference of a flywheel to a satellite platform can be effectively reduced; and technical support is provided for development of a high-accuracy high-resolution high-stability extra-static platform.
Owner:SHANGHAI SATELLITE ENG INST

Low-level recursion minimum mean-square error evaluation of MIMO-OFDM channel

The invention discloses a low-order recurrence least mean square error estimation for an MIMO-OPDM channel, which relates to the wireless transmission technical field. After a pilot frequency is used to insert in to obtain a recurrence least square estimation of a time-varying channel fading, the channel fading is decomposed into a signal subspace and a noise subspace by adopting a subspace tracking method of being capable of tracking singular values and singular vectors under the non-stationary complicated noise, then an order-reduction is made according to the quantity of main singular values to obtain an auto-correlation matrix of the channel fading, and a least mean square error estimation with higher precision is obtained through the recurrence. The invention has the characteristics of having computation complexity of decreasing algorithm, higher estimation accuracy as well as good robustness and applicability, and being capable of providing channel estimation and self-adaptive equalization proposals of systems such as third generation (3G) cell mobile communication, beyond third generation (B3G) cell mobile communication, fourth generation (4G) cell mobile communication and digital TVs, wireless local area networks (WLAN), wireless wide area networks (WWAN) and so on, with an important theoretical evidence and a concrete realization method and so on.
Owner:SHANGHAI NORMAL UNIVERSITY

Free-hand sketch offline identification and reshaping method

The invention discloses a free-hand sketch offline identification and reshaping method. The method comprises the following steps of: preprocessing an input image; converting a discrete and disordered point set in each connected domain into an ordered point sequence for compression; fitting a plurality of straight lines of the point sequence by using a dynamic programming algorithm, and determining the number of optimum fitted straight lines to obtain the strokes, represented by the straight lines, of each connected domain; analyzing a stroke result obtained by fitting the plurality of straight lines; if the number of the fitted straight lines is greater than the maximum edge number of a shape identified by a system, performing order reduction on the strokes, classifying the strokes, and calculating distance between the strokes; and selecting the nearer strokes for combination and analysis, and performing verification according to the geometrical characteristic to determine the shape formed by combination of the input strokes. The method is higher in identification rate, and the shape to be identified has scale invariance and rotation invariance; and the algorithm supports a multi-stroke form for identifying limited shapes, and the problems in the identification completely based on the geometrical characteristic are solved.
Owner:XI AN JIAOTONG UNIV

Operation instrument for optical tweezers

The invention relates to an operation instrument for optical tweezers. The operation instrument comprises a laser source, a convex lens, a plane mirror, a two-tone spectroscope, optical wedges, a focusing objective lens, a sample table, a sample pool, an illuminating light source and a CCD camera. Light beams are emitted by the laser source, expanded and shaped by a light beam coupler, and then are converged and irradiated by the plane first mirror, the two-tone spectroscope, the two deflection optical wedges and the focusing objective lens into the sample pool to capture target particles, the first optical wedge and the second optical wedge are driven by a motor to deflect around the Y axis and the X axis respectively in an orthogonal mode, the deflection angle can be measured through an angle sensor, the deflection of the light beams is controlled, and the target particles are moved; the particle capturing and moving process can be visually acquired through the CCD camera and a displayer. When the particles move in the plane parallel to the XOY plane, the sample pool does not need to move, namely, the particles are not affected by external vibration in the moving process; in addition, due to the fact that the two orthogonal deflection optical wedges can achieve the light beam deflection hundredfold-order reduction ratio, the deflection directions of the light beams can be accurately controlled, and the light beams can capture the particles accurately and carry the particles to move firmly.
Owner:TONGJI UNIV

Underwater robot control method based on reinforcement learning and control method of tracking with underwater robot

The invention discloses an underwater robot control method based on reinforcement learning and a control method of tracking with an underwater robot, belonging to the technical field of underwater robot control. According to the methods provided by the invention, a control center gives desired trajectory information of the underwater robot, and sends the information to the underwater robot; according to a probability density function of uncertain parameters in an underwater robot model, sampling points are respectively selected for the uncertain parameters, and order reduction is executed foran original dynamical model based on the sampling points; the underwater robot performs interaction with surrounding environment so as to learn environment information, a one step cost function is calculated at different states and value updating is executed, weight of a value function corresponding to a control strategy is solved through a least square method, improvement of the control strategyis executed through a gradient descent method, loop iteration is executed for two processes of value updating and strategy improvement until convergence is realized, and consequently, an optimal control strategy of current position tracking desired trajectory is obtained; and steps above are repeated for obtaining the optimal control strategy for the rest desired trajectory tracking, and finally,a tracking task is completed.
Owner:芽米科技(广州)有限公司

Prediction-correction algorithm-based aircraft global pneumatic optimization method

The invention discloses a prediction-correction algorithm-based aircraft global pneumatic optimization method, and aims at solving the technical problem that the conventional aircraft global pneumatic optimization methods are low in efficiency. The technical scheme is that the method disclosed in the invention comprises the following steps: firstly carrying out prediction optimization: building an agent model through collecting flow field snapshots, and carrying out preliminary screening on the design space according to a genetic algorithm so as to obtain approximate points of a global optimum point; and carrying out correction optimization: carrying out pneumatic optimizing by utilizing an adjoint gradient and a gradient optimization algorithm to ensure that the predicted approximate points are rapidly converged to the global optimum point. According to the method disclosed in the invention, a flow field order reduction model is constructed by repeatedly using the previously obtained flow field snapshots during the optimization in the step 2, so as to rapidly predict a to-be-calculated flow field, and then correction is carried out on the prediction value by utilizing a full-order flow field solver. Compared with the methods in background technology, the method disclosed in the invention has the effect of improving the calculation efficiency of the flow fields; and for the two-dimensional optimization problem, the calculation of flow field numerical values is reduced from about 200 times in the background technology to about 70 times, so that the optimization effect is remarkable.
Owner:NORTHWESTERN POLYTECHNICAL UNIV

Vibration suppression method for flexible manipulators

The invention discloses a vibration suppression method for flexible manipulators. According to the method disclosed by the invention, a model compensation based control method is adopted, and a model is associated with a speed control ring and composed of an electrical component model and a mechanical component model which are subjected to order reduction. The difference value between the speed of a driven mechanical component and the speed of a motor is subjected to real-time calculation and multiplied by a factor, and then the obtained value is added into a speed instruction of the motor, thereby achieving an effect of suppressing the transient vibration of the driven mechanical component. According to the invention, the model compensation based control method is adopted, and a non-time-delay damping effect is established on the driven mechanical component, namely that a vibration attenuation effect is achieved, thereby effectively shortening the stabilization time of a system, and improving the vibration suppression control accuracy of flexible manipulators. The load speed is assessed through the model, thereby reducing the cost of hardware such as sensors and the like. Model parameters are acquired according to experimental data, and the parameters can be subjected to on-site adjustment; and the control method is simple, and easy to realize.
Owner:NANJING ESTUN AUTOMATION CO LTD +1

Elastic aircraft flight dynamics modeling method based on nonlinear aerodynamic force order reduction

The invention provides an elastic aircraft flight dynamics modeling method based on nonlinear aerodynamic force order reduction, which is suitable for engineering and is used for realizing elastic aircraft flight dynamics simulation, especially gust response high-precision and high-efficiency simulation under the condition that a low-speed aircraft encounters large-amplitude gust. The method comprises the following steps: firstly, establishing a rigid-elastic coupling kinetic equation of the elastic aircraft, then solving generalized aerodynamic force in a given motion or incoming flow state based on CFD, and obtaining training input and output signals of a reduced-order model; an ARMA model and an RBF neural network model are adopted to establish a linear aerodynamic order reduction model and a nonlinear correction model respectively, and the linear aerodynamic order reduction model and the nonlinear correction model are combined to obtain a nonlinear aerodynamic order reduction model; and then coupling the nonlinear aerodynamic reduced-order model and the rigid-elastic coupling kinetic equation to carry out flight kinetic simulation on the elastic aircraft. Compared with a traditional simulation method based on surface element method aerodynamic force, the method is high in precision and efficiency compared with a CFD / CSD coupling analysis method, and has high engineering value.
Owner:BEIHANG UNIV

Permanent magnet synchronous motor d-axis and q-axis induction parameter on-line identification method and system

The invention discloses a permanent magnet synchronous motor d-axis and q-axis induction parameter on-line identification method and a system. The method comprises sampling a d-axis voltage u<d), a q-axis voltage u<q>, a d-axis current i<d> and a q-axis current i<q> of a permanent magnet synchronous motor in a dq coordinate system; and, according to the d-axis voltage u<d), the q-axis voltage u<q>, the d-axis current i<d> and the q-axis current i<q>, regarding the back electromotive force efficient and a phase resistance R<s> of the permanent magnet synchronous motor as constants, performing order reduction processing on a least square method, and calculating to obtain a q-axis induction parameter L<q> of the permanent magnet synchronous motor and a d-axis induction parameter L<d> of the permanent magnet synchronous motor. According to the d-axis voltage u<d), the q-axis voltage u<q>, the d-axis current i<d>, the q-axis current i<q> and an order reduction calculation model based on the least square method, the q-axis induction parameter L<q> and the d-axis induction parameter L<d> of the permanent magnet synchronous motor are calculated, and then the problem of the large calculated amount in an existing method for achieving permanent magnet synchronous motor parameter on-line identification based on the least square method is effectively solved.
Owner:GREE ELECTRIC APPLIANCES INC

An unsteady aerodynamic force order reduction method based on generalized aerodynamic force

The invention provides an unsteady aerodynamic force order reduction method based on generalized aerodynamic force. The method comprises steps of firstly, converting generalized aerodynamic force under modal coordinates into unsteady aerodynamic force distributed on all nodes of a structural finite element model under physical coordinates through coordinate transformation; secondly, performing order reduction on the distributed unsteady aerodynamic force through curved surface spline interpolation, equivalently concentrating the unsteady aerodynamic force to a limited loading point so as to obtain a frequency domain aerodynamic force order reduction model, and finally fitting the frequency domain order reduction aerodynamic force model to a time domain by using a minimum state method. According to the method, the precision of the reduced-order aerodynamic model is improved on the basis of reducing the order of the reduced-order aerodynamic model as much as possible, so that the difficulty of designing an excitation force control system in a ground flutter simulation test is reduced, and the reduced-order method can be used for transonic flutter analysis by means of a CFD transonicvelocity unsteady aerodynamic calculation method.
Owner:NORTHWESTERN POLYTECHNICAL UNIV

Cold-rolled sheet shape closed-loop control method and system

ActiveCN109433830AMaximize controlReal-time online adjustmentProfile control deviceLoop controlOrder reduction
The invention discloses a cold-rolled sheet shape closed-loop control method and system. The cold-rolled sheet shape closed-loop control method comprises the steps: evaluation functions synergistically controlled by cold-rolled sheet shape executing mechanisms are built according to cold-rolled sheet shape regulating and controlling efficacy coefficients; k-time solution vectors of the executing mechanisms are determined according to the evaluation functions; whether the k-time solution vectors are within feasible regions of the cold-rolled sheet shape executing mechanisms or not is judged, and if yes, the k-time optimal regulating variables are obtained; if not, evaluation functions harmoniously controlled by the cold-rolled sheet shape are determined, and gradient informationof the evaluation functions and the regulating directions of the cold-rolled sheet shape executing mechanisms are determined according to parameters of the cold-rolled sheet shape executing mechanisms; final values of the regulating variables of the executing mechanisms are determined according to the gradient information and the regulating directions; the evaluation functions are subjected to order reduction according to the final values, evaluation functions subjected to order reduction are obtained, and (k+1)-time solution vectors are determined, wherein the relation of k=k+1 is made to be met; and the cold-rolled sheet shape is adjusted according to the k-time optimal regulating variables of all the cold-rolled sheet shape executing mechanisms. According to the cold-rolled sheet shape closed-loop control method and system, the sheet shape regulating speed can be increased.
Owner:桐城市建设投资发展有限责任公司

System and method for calculating time lag stability upper limit based on generalized eigenvalue

The invention discloses a system and method for calculating the time lag stability upper limit based on the generalized eigenvalue and belongs to the technical field of analysis of the stability of an electric power system. The system for calculating the time lag stability upper limit based on the generalized eigenvalue comprises a data acquisition module, a time lag system processing module, a time lag upper limit solving module and a result output module, wherein the data acquisition module, the time lag system processing module, the time lag upper limit solving module and the result output module are connected in sequence. The method for calculating the time lag stability upper limit based on the generalized eigenvalue comprises the steps that network structural parameters, the frequency of an electric generator and the power angle of the electric generator are collected, wherein the network structural parameters, the frequency of the electric generator and the power angle of the electric generator are needed for establishing a time lag system state equation; the time lag system state equation is established, order reduction is conducted on a parameter matrix in the time lag system state equation, and a time lag system state equation with the order reduced is obtained; a time lag stability criterion based on an improved free weight matrix is generated; the time lag stability upper limit is solved according to the time lag stability criterion. According to the system and method for calculating the time lag stability upper limit based on the generalized eigenvalue, the conservation of time lag stability upper limit calculation can be effectively reduced, and the correctness and effectiveness are high.
Owner:NORTH CHINA ELECTRIC POWER UNIV (BAODING)
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