11 results about "Linear term" patented technology

The invention discloses a Tokamak plasma magnetic response model construction method, a Tokamak plasma magnetic response model construction system and a medium. Relates to the technical field of nuclear fusion plasma simulation. According to the scheme, improvement is carried out on the basis of the prior art, modeling is carried out on the magnetic response of the Tokamak plasma on the basis of basic data of the Tokamak plasma, and plasma behaviors are directly learned from experimental data; the simulator taking the plasma magnetic configuration evolution autoregression model as a carrier can process nonlinear terms and high-order terms, and is low in calculation cost, high in speed and capable of being applied in real time; according to the method, the behavior of the plasma under magnetic control can be well simulated, the plasma behavior is directly learned from experimental data without simplifying and assuming plasma properties, and the method can be used for off-line simulation and can also be used for control strategy optimization or fault detection in real time.

The present application belongs to the field of gear design, and particularly relates to a design method of a drum-shaped modification curve of gear tooth direction, comprising: 1) constructing a whole C 2 smoothly continuous double circular-arc spline drum-shaped modification curve; 2) obtaining the coordinates of the common tangent point F i of the i-th double circular-arc segment of the double circular-arc spline drum-shaped modification curve; 3) constructing a multi-element nonlinear equation set; 4) obtaining an initial solution by solving the linear term of the equation set, and iteratively calculating the accurate solution of the multi-element nonlinear equation set; and 5) obtaining the drum-shaped modification curve of the gear tooth direction according to the accurate value of the intermediate variable chord tangent angle of the i-th double circular-arc segment. The drum-shaped modification curve of the gear tooth direction obtained by the present application adopts segmented low-order interpolation, can avoid the "Runge" effect of high-order interpolation, and has good properties of the first and second order derivatives of the drum-shaped curve. The curve has high fitting accuracy, is continuous and smooth, reduces the impact and vibration in the gear transmission process, improves the tooth surface contact state, and improves the gear transmission performance.

The invention relates to the technical field of rock stress analysis, in particular to a rock stress distribution analysis method, device and equipment and a medium. The method comprises the following steps: calculating a linear term required for solving a rock stress function according to principal stress applied to rock and a direction angle of the principal stress, mapping a pore boundary into a unit circle boundary on a complex plane based on conformal transformation, and performing Cauchy integration based on the unit circle boundary to obtain a nonlinear term required for solving the rock stress function. And obtaining an expression of a stress function based on the linear term and the nonlinear term, and finally calculating stress distribution generated in the rock according to the expression of the stress function. According to the method, the complex and irregular pore boundary is mapped into the regular unit circle boundary by adopting conformal transformation so as to reduce the calculation amount required for solving the stress function, and the pore boundary in any shape can be mapped into the unit circle boundary through conformal transformation, so that the calculation amount is reduced; therefore, the stress analysis method is suitable for stress analysis of rocks with pores in any shape.

The invention discloses an arbitrary-dimension simplest memristor Hamilton conservative chaotic system and a construction method and application thereof, and belongs to the technical field of information security. According to the system, a voltage difference type three-terminal memristor model is firstly built, then an n-dimensional Hamilton conservative chaotic system general formula is built, the memristor model is introduced into the n-dimensional Hamilton conservative chaotic system general formula, the simplest system is obtained through the steps of element replacement, parameter setting and the like, and multi-scroll expansion can be achieved by introducing a nonlinear function. A system mathematical model is simple, the proportion of nonlinear terms is low, hardware is constructed based on an ARTIX-7 FPGA platform, a 36Q32 format fixed-point number is adopted, resource consumption is low, data throughput is high, and output sequence randomness is high. The system can be applied to the fields of artificial intelligence data enhancement and random signal generation, provides a new path for high-dimensional conservative chaotic system modeling, and is suitable for information security application of resource-limited scenes.

The application discloses a SAR motion parameter estimation method based on accurate measurement of time of arrival and direction of arrival, which comprises the following steps: reading N LFM direction of arrival alpha n and corresponding measurement value of time of arrival t n , performing cubic polynomial fitting on the line of sight angle alpha n by using a least square method to smooth measurement error; performing quadratic polynomial fitting on the time of arrival t n by using a least square method to obtain a linear term coefficient p1 and a quadratic term coefficient p2; obtaining a radar pulse repetition interval T by using a statistical pulse time of arrival difference; updating a detection pulse serial number n; solving a radar initial distance r0; and solving a radar flight speed v and a flight direction beta by using the initial distance r0, the direction of arrival alpha n and the time of arrival t n . The application has the characteristic that a signal waveform of a SAR emission is synthesized with an LFM pulse, accurate estimation of SAR motion parameters is realized, the variation rate parameter of the line of sight angle is avoided, and the robustness of the algorithm is improved and the requirement for the direction finding accuracy is reduced.

The invention belongs to the technical field of permanent magnet synchronous motor control, and discloses a sensorless control method and device for a permanent magnet synchronous motor, and the method comprises the steps: building a super-spiral sliding-mode observer, introducing an observation error linear term in the super-spiral sliding-mode observer, and constructing a second-order sliding-mode model; constructing a back electromotive force adaptive optimization module in the super-spiral sliding mode observer by adopting a complex coefficient filter; constructing a phase-locked loop by adopting a fourth-order active-disturbance-rejection algorithm, and estimating a rotor position error in real time by adopting a state expansion observer; a primary linear expansion state observer and a secondary linear expansion state observer are connected in series to form an improved linear active disturbance rejection controller. According to the method, buffeting of the sliding-mode observer can be suppressed, and the counter electromotive force estimation precision is improved; the dynamic response capability of the system under the working conditions of medium-high speed and sudden loading is enhanced, the method is more suitable for complex working conditions of high speed, variable load and the like, and the robustness and the control precision of the system are remarkably improved.

The invention discloses a high-dimensional feature screening method and device based on quantum annealing, relates to the technical field of quantum computing, and realizes accurate and efficient feature screening in a high-dimensional financial data scene. The method comprises the following steps: acquiring data of a target financial variable and data of a to-be-preliminarily screened characteristic factor; constructing an initial total prediction linear term based on a linear term of the secondary unconstrained binary optimization model, and obtaining a selected to-be-primarily-screened characteristic factor as a to-be-finely-screened characteristic factor; based on a linear term and a quadratic term of the quadratic unconstrained binary optimization model, constructing a total prediction linear term and a redundant quadratic term, and obtaining a selected to-be-finely screened characteristic factor as a to-be-optimized characteristic factor; the permutation importance of each to-be-optimized feature factor is calculated, a target feature factor is screened from the to-be-optimized feature factors according to the permutation importance, and the target feature factor is used for predicting a target financial variable.

The application relates to a Hammerstein dynamic hysteresis model based on an improved asymmetric generalized Prandtl-Ishlinskii model, relates to the technical field of servo control, and comprises the following steps: introducing a double exponential function of a deviation factor and adding a linear term in an envelope function; based on the double exponential function envelope with the deviation factor, an improved asymmetric generalized Prandtl-Ishlinskii model is constructed according to a formula; an ARX model structure is adopted to capture the dynamic linear characteristics of a system; the improved asymmetric generalized Prandtl-Ishlinskii model is taken as a static nonlinear part of a Hammerstein model, and an ARX dynamic model is taken as a dynamic linear part of the Hammerstein model; and the output of the Hammerstein dynamic hysteresis model is used to verify the results and application cases. The application improves the existing asymmetric generalized Prandtl-Ishlinskii model, introduces the double exponential function envelope with the deviation factor, and can more accurately describe the asymmetric hysteresis characteristics.

The invention relates to a fluid-structure interaction dynamics simulation test method and system for a canopy and an optimization method. The simulation test method comprises the following steps: dispersing the canopy into a mass-spring-damping grid model; defining an elastic force expression containing a linear term and a nonlinear term for the spring unit, and calibrating a key coefficient through a material test or an empirical formula; establishing a control equation containing nonlinear elastic force, damping force and aerodynamic force; and fluid-structure interaction numerical solution is carried out, and the whole-process dynamic behavior of the canopy from parachute opening to stable descending is simulated. The optimization method comprises the steps of comparing a simulation result with a design index, and adjusting a local design parameter based on a diagnosis result and performing iteration until a requirement is met. The simulation precision and reliability of large-deformation nonlinear response, aerodynamic performance and complex fluid-solid coupling phenomena of parachute canopy fabric are remarkably improved, and an effective numerical simulation tool is provided for design optimization of flexible structures such as supersonic parachutes.

The design method of the non-linear term offset moving coil magnetic single-acting vibrator meets the following conditions: (1) a moving coil magnetic single-acting vibrator body comprises an outer cylinder, a vibration transmission sheet, a stator assembly and a rotor assembly; (2) 2N magnetic domains D1, i and D2 which are designed in pairs are arranged in the moving-coil magnetic single-acting oscillator body, i and N are 1, 2, 3,..., 100, and i = 1, 2, 3,...; and (3), the mover assembly is subjected to electromagnetic acting force of pushing force and pulling force in pairs at the same time, the push-pull type structural characteristic is presented, the mover assembly is subjected to interaction of the pushing force and the pulling force, linear terms in component force of the mover assembly are overlapped and become large, and the linear terms in the component force of the mover assembly become large. And non-linear terms in the component force of the mover assembly are partially or completely counteracted and are reduced.