10 results about "Excitation function" patented technology

The application belongs to the technical field of tunnel geological advanced prediction, and provides an electromagnetic controllable excitation device and method for longitudinal and transverse wave excitation of a deep-buried tunnel. The excitation device comprises a body, longitudinal and transverse wave excitation plates arranged on the body, and a rotating mechanism arranged on the body. The longitudinal and transverse wave excitation plates are perpendicular to each other, and the rotating mechanism is connected with a mechanical arm. The rotating mechanism is used to realize the operation switching of the longitudinal and transverse wave excitation plates at the same physical position, and longitudinal and transverse wave excitation is performed. The longitudinal and transverse wave excitation functions are integrated in a single excitation device, the structure is compact, and the device is suitable for operation requirements in a narrow space area in a tunnel. The rotating mechanism is used to realize 90-degree rapid switching, the detection efficiency is greatly improved, the physical positions of two times of excitation are completely consistent, and the data comparability is improved.

The invention belongs to the technical field of tunnel geology advanced prediction, and provides an electromagnetic controllable excitation device and method for longitudinal and transverse wave excitation of a deep tunnel, a vibration exciter comprises a body, a longitudinal wave excitation plate and a transverse wave excitation plate which are arranged on the body, and a rotating mechanism arranged on the body; the longitudinal wave excitation plate and the transverse wave excitation plate are perpendicular to each other, and the rotating mechanism is connected with the mechanical arm. Operation switching of the longitudinal wave excitation plate and the transverse wave excitation plate at the same physical position is realized through the rotating mechanism, and excitation of longitudinal waves and transverse waves is carried out; the longitudinal wave excitation function and the transverse wave excitation function are integrated into a single vibration exciter, the structure is compact, the device meets the operation requirement of a narrow space area in a tunnel, 90-degree rapid switching is achieved through the rotating mechanism, the detection efficiency is greatly improved, it is ensured that physical positions of two times of excitation are completely consistent, and the data comparability is improved.

A MEMS device temperature drift error estimation model parameter precision identification method is provided to solve the problem of low precision of MEMS device output caused by low precision of temperature drift error estimation model output. The MEMS device temperature drift error estimation model based on RBFNN is initialized; the excitation function configuration set of RBFNN is constructed; the model is trained according to the training sample and the configuration set, and the MEMS device output and the corresponding temperature drift error are compensated by using the temperature drift error; the mean square error of the compensated MEMS device output is taken as the precision index, the actual calculation time of the compensated temperature drift error estimation is taken as the real-time index, and the two are taken as the input, the configuration set is taken as the output expert knowledge base; the knowledge base is decomposed by using the fuzzy theory, the best excitation function configuration scheme is obtained according to the precision index target value and the real-time index target value, the trained model is updated, and a new model is obtained; the environmental temperature is used to output the temperature drift error by using the new model, and the MEMS device output is compensated.

The invention relates to the technical field of rolling bearing fault diagnosis, and discloses a full-life rolling bearing fault diagnosis method based on mechanism data migration. The method comprises the steps that a rolling body radial displacement excitation function, the time-varying contact rigidity of a rolling body and a bearing raceway and the impact force at the contact defect position of the rolling body in a mass-spring-damping model are corrected based on the Hertz contact theory, and a nonlinear kinetic equation of the rolling bearing is obtained; solving a nonlinear kinetic equation of the rolling bearing through a fourth-order Runge-Kutta method, generating source domain data consistent with test parameters of the full-life rolling bearing, and constructing a source domain data set with a complete fault tag; according to the method, the dynamic mechanism model consistent with the full-life test bearing parameters is constructed, the feature distribution difference between the generated source domain data and the target domain data is small, a foundation is laid for efficient knowledge migration, and the problem that traditional source domain data is not matched with actual data is solved.

The invention discloses a radio interference calculation method and device for a high-altitude ultrahigh-voltage alternating-current transmission line. The method comprises the following steps: calculating to obtain the maximum field intensity of the surface of a wire according to the structural parameters and the operating voltage of a line; respectively calculating a rainy day radio interference excitation function and a good weather radio interference excitation function based on the maximum field intensity of the surface of the conductor, the structural parameters of the line and the meteorological parameters of the target area; calculating the radio interference current of each phase conductor through mode transformation according to the rainy day radio interference excitation function and the good weather radio interference excitation function; and according to the radio interference current, the radio interference levels of good weather and rainy days under the influence of different meteorological conditions are solved.

The invention discloses a rolling bearing fault modeling and response prediction method based on defect edge evolution, and belongs to the technical field of mechanical system dynamics and health state evaluation. Firstly, a rolling bearing dynamical model is established based on a lumped parameter method, a raceway defect is divided into three parts according to the running state of the defect of a rolling body, and independent parameters are introduced to describe the morphology characteristics of each part of the defect. And establishing a segmented time-varying displacement excitation function based on the geometric parameters, coupling the segmented displacement excitation function to a nonlinear contact model to form a kinetic equation containing local defect characteristics, and calculating the time-history response of the system. According to the method, time domain and frequency domain analysis is carried out based on a time history response result, prediction of bearing response characteristics under different defect morphologies and evolution processes is realized, the method has high prediction precision and good engineering applicability, and effective theoretical and method support is provided for fault mechanism modeling, state monitoring and service life evaluation of the rolling bearing.

The invention discloses a plasma turbulence evolution simulation method and system with configurable external excitation, and relates to the technical field of magnetic confinement nuclear fusion plasmas, and the method comprises the steps: obtaining a time-varying external excitation function defined by a user; coupling the time-varying external excitation function into the wave number spectrum evolution physical model, and constructing an expansion coupling equation set; at each time step, based on the current plasma state parameter and the current value of the time-varying external excitation function, discretizing the extended equation set in a wavenumber space, and constructing a tridiagonal linear equation set; solving the tridiagonal linear equation set by adopting a chasing method to obtain turbulence potential function distribution of each time step; calculating the turbulence characteristic physical quantity of each time step according to the turbulence potential function distribution of each time step; and generating a time evolution curve of the turbulence characteristic physical quantity in real time. According to the method, a time-varying external excitation function is defined by a user, so that the problem that a constant driving model cannot reflect excitation time-varying characteristics in the prior art is solved.

The application discloses a kind of local defect dynamics modeling method of rolling bearing considering defect edge contact behavior and interface slip representation, first, the dynamics model of rolling bearing is established, and the multi-degree-of-freedom dynamics system of the motion state of rolling body is described;Based on the physical diameter effect of rolling body itself, progressive edge contact local fault displacement excitation function is established;Second, the inner raceway compression, outer raceway compression and contact force in the contact between rolling body and inner raceway, outer raceway are calculated, and the relative velocity and friction force of rolling body and inner raceway, outer raceway;Then, the constraint of cage to rolling body is modeled as spring-damping system, and the constraint force of cage to rolling body is calculated;Then, the dynamics equation of inner raceway, outer raceway, the jth rolling body and additional support in X axis and Y axis of rolling bearing with defect is established;Finally, the established dynamics equation is solved, and the vibration response signal for condition monitoring and fault diagnosis is obtained.

The invention discloses a dynamic modeling method for IAS response disturbance caused by initial peeling extension evolution of a deep groove ball bearing outer ring. Comprising the following steps: establishing a fault model of initial peeling of an outer ring raceway, performing parametric modeling on a sharp edge, an arc edge and an oblique angle sharp edge before and after peeling evolution, and calculating contact deformation before and after a rolling body passes through a peeling area. Calculating the normal contact force between the rolling body and the inner and outer ring raceways, considering a rolling resistance friction model and additional displacement excitation, and deducing an angle change tangential force excitation function; and respectively deducing the tangential impact forces of the three edge shapes in the evolution process of the spalling region. Through an angular domain modeling method, an angle sequence is used as an independent variable, an instantaneous angle parameter is explicitly expressed in a differential equation, an IAS dynamic differential equation set of initial peeling evolution of the outer ring of the deep groove ball bearing is constructed, and a fourth-order Runge-Kutta method is used for solving IAS response of the bearing. And the IAS dynamic response of the deep groove ball bearing during initial peeling evolution of the outer ring raceway can be effectively and accurately obtained.

The present application relates to a kind of statistical and physical combination (n, alpha) reaction cross section experimental data evaluation method, belong to nuclear data evaluation technical field, the method includes the following steps: investigation and collection existing (n, alpha) reaction cross section experimental data, and collect the relevant information of experimental data, determine the experimental method of experimental data, experimental purpose, detector information, to experimental data is mathematically and physically analyzed, understand the distribution law of experimental data, find implicit variable;According to implicit variable, experimental data is classified and analyzed to obtain experimental data evaluation result;And with the experimental data after evaluation as the basis, obtain recommended excitation function by mathematical fitting etc..The method of the present application starts from two aspects of mathematics and physics, finds the "implicit variable" that influences the accuracy of data in Simpson paradox, from the angle of experimental data evaluation, can effectively avoid the occurrence of PPP problem, effectively improve the accuracy of evaluation data and the efficiency of evaluation work.