66 results about "Damping matrix" patented technology

The invention relates to the field of geographic information technology and natural resource management, and discloses an automatic analysis system for land utilization flow change in land change investigation. The system comprises an object-level spatiotemporal spectrum tree reconstruction and data initialization module, a topological potential energy field construction module based on evolution entropy, a multi-scale geometric difference extraction and morphological analysis module, a variable stiffness topological adsorption and decoupling module based on a stiffness ratio, and a flow damping filtering and event serialization module driven by semantic rules. The system constructs a topological potential energy field by using a historical state vector and semantic stiffness, performs one-way adsorption, adjustment or retention on a difference polygon according to relative stiffness, and cleans invalid traffic based on a damping matrix. According to the method, through physical field simulation and semantic logic verification, high-frequency disturbance misjudgment is effectively eliminated, pattern spot boundary correction is ensured to conform to the legal weight, and the authenticity and logic self-consistency of change survey data are improved.

A method for rapidly solving transient dynamics of a crack-containing bearing structure of a bogie belongs to the technical field of bogie structure dynamic analysis, and comprises the following steps: acquiring a three-dimensional geometric model of the bearing structure, the geometric dimension of a crack and the position coordinate dimension of the crack; dividing the finite element model of the bearing structure, and carrying out grid division processing on the crack surface; selecting a main degree-of-freedom node of the finite element model on the surface of the bearing structure and the crack surface; performing substructure analysis on the finite element model of the bearing structure; obtaining a mass matrix, a damping matrix and a stiffness matrix of the finite element model of the bearing structure after the degree of freedom is reduced; carrying out constraint simulation on a crack surface node by adopting a one-way nonlinear rigidity unit; processing constraint boundary conditions; processing the excitation load; and solving a dynamic second-order differential equation set, and judging whether the crack surface is in contact or not. According to the method, the opening and closing effects of the crack can be considered, the transient dynamic response of the crack-containing bearing structure under the action of the external load is obtained, and the solving precision and efficiency are both considered.

The invention relates to a mechanical arm self-adaption compliance control method and system based on model reference self-adaption and impedance parameter online identification, and belongs to the field of robots. The method comprises the steps that a mechanical arm task space dynamics model is established; designing a reference model; a recursive least square method is adopted, and an equivalent stiffness matrix and a damping matrix of the interaction environment are identified online; designing a composite adaptive law; the expected rigidity of the reference model is dynamically adjusted according to the environment rigidity obtained through identification; and according to sensor data collected in real time, the mechanical arm task space dynamics model, the robot parameter self-adaption law, the environment rigidity, the environment damping and the environment parameter identification robust item, control force is generated, and the mechanical arm is driven through the control force. According to the method and the system, the environment characteristics can be sensed online, and the compliant behaviors can be adaptively adjusted, so that safe, efficient and high-robustness interaction of the mechanical arm in a complex and unknown environment is realized.

The invention relates to the technical field of unit gap vibration testing, in particular to a unit gap vibration testing method based on transient numerical simulation, and the method comprises the steps: building a multi-degree-of-freedom dynamic model through obtaining unit structure parameters and operation parameters, carrying out the global optimization of stiffness matrix and damping matrix parameters through employing a genetic algorithm, and generating a high-precision dynamic model; a thermal fluid coupling module is integrated in the model, a coupling weight factor is dynamically corrected in combination with a particle swarm optimization algorithm, a multi-physical-field unsteady-state coupling vibration response equation is generated, and a Pareto optimal solution set is solved in combination with a multi-objective genetic algorithm to optimize gap parameters. According to the invention, real-time evaluation of the vibration state and closed-loop output of fault early warning signals are realized. According to the invention, the problem of insufficient characterization of unsteady state multi-field coupling characteristics in the prior art is solved, and high-precision technical support is provided for online monitoring of rotating machinery.

The invention discloses an industrial robot tail end vibration response calculation method and system, solves the problem of how to improve industrial robot tail end dynamic response prediction accuracy, and belongs to the field of industrial robot dynamics analysis. According to the method, elements of the industrial robot are regarded as rigid bodies or flexible bodies, all assemblies are integrated into a rigid-flexible coupling dynamic model in combination with a robot kinematic model, step-by-step parameter identification is conducted on the decoupled rigid body dynamic model and structural dynamic model, inertial parameters are identified by considering the influence of nonlinear joint friction, and the method is suitable for industrial robot control. Further identifying a rotational inertia matrix in the robot milling kinetic model; joint elastic parameters are identified by considering the influence of non-linear joint rigidity, and a damping matrix in a robot milling kinetic model is further identified. And the torque fluctuation of each joint is predicted, the vibration response of each joint is calculated in combination with a robot milling kinetic model, and finally the robot tail end vibration response is calculated in combination with robot kinematics.

The invention discloses a vibration detection method for constructing an edge calculation model based on Simulink physical modeling, and the method comprises the steps: constructing a multi-degree-of-freedom vibration model through Simulink, dynamically adjusting the quality, rigidity, a damping matrix, temperature and load parameters, simulating the vibration characteristics of a complex working condition, and fusing simulation and actual measurement data to generate a training set; the model is converted into an edge available format and compressed to be within 100 KB, and edge hardware is adapted; carrying out joint training and online updating on edge nodes by utilizing transfer learning and the like; and the vibration signals are classified in real time through a lightweight model. According to the method, the problems of fixed model parameters, insufficient data fusion and poor edge adaptability in the traditional technology are solved, accurate simulation of the vibration characteristics of the industrial equipment, efficient data utilization and low-delay detection of the edge end are realized, the vibration detection precision and real-time performance are improved, and the method is suitable for fault diagnosis and predictive maintenance of the industrial equipment.

The invention discloses a viscoelastic boundary verification method, device and equipment based on isoparametric elements and a medium, and the method comprises the steps: building a three-dimensional geometric model of a target structure according to geometric dimensions and material attributes, discretizing the three-dimensional geometric model into initial three-dimensional subunits, and then building an initial finite element mesh model; after identifying a target boundary surface to be applied with an artificial viscoelastic boundary, assigning boundary parameters to obtain each three-dimensional subunit and form a finite element model; all the three-dimensional subunits are mapped to a standard unit through equal-parameter coordinate transformation, an equivalent stiffness coefficient matrix and an equivalent damping coefficient matrix are obtained through calculation and then stacked and assembled, and an overall stiffness matrix and an overall damping matrix are formed; and calculating displacement response data based on the overall stiffness matrix and the overall damping matrix. According to the embodiment of the invention, by introducing the isoparametric coordinate transformation, the irregular boundary form can be directly processed without introducing an additional boundary unit, and the calculation requirement of an actual complex engineering model is met.

The invention relates to the technical field of data processing, in particular to a structure dynamic stiffness analysis method based on frequency response function polycondensation substructure impedance coupling, which comprises the following steps: acquiring node information, unit connection relation and material attribute based on a global finite element model; defining a focus point set, a boundary point set and an internal point set according to the unit connection relationship; partitioning the global quality matrix, the stiffness matrix and the damping matrix to obtain a partitioned system matrix; introducing an inertia compensation term to construct a transformation matrix based on the block system matrix and the highest analysis frequency of the system, condensing the system matrix until only the freedom degrees of a concern set and a boundary point set are reserved, and calculating a dynamic stiffness matrix in a frequency domain; a dynamic stiffness result of a focus set is extracted through inverse operation of a dynamic stiffness matrix, the calculation scale is remarkably reduced through system matrix condensation, meanwhile, the inertia effect and the stiffness coupling effect of a far-field structure are strictly reserved, and the contradiction between low calculation efficiency of a global model and precision distortion of a local substructure method is effectively solved.

The invention discloses a structure parameter-load input joint identification method based on a Gaussian potential force model, and the method comprises the steps: obtaining a mass matrix, a stiffness matrix and a damping matrix, and constructing a state-space equation; modeling unknown load input into a zero-mean stationary Gaussian process with a specific covariance function to fuse prior information of the covariance function, and converting into an equivalent state-space equation; obtaining sparse dynamic response characteristics, and establishing a state space measurement equation; a structure state and load input are augmented into a state equation, the state equation and a measurement equation set are synthesized into a complete Gaussian process potential force model, unknown structure parameters are regarded as hyper-parameters, kernel function hyper-parameter optimization and structure parameter identification are achieved with the criterion of a maximized negative likelihood function, sequence reasoning is conducted on the Gaussian process potential force model, and the Gaussian process potential force model is obtained. Estimation of load input is obtained. The method has the advantages of being stable in parameter recognition result, high in precision, stable and reliable in load estimation, higher in robustness to model errors and measurement noise and the like.

The invention discloses a vehicle time history response calculation method and device, electronic equipment and a storage medium. The method comprises the following steps: acquiring a mass matrix, a damping matrix and a stiffness matrix of a to-be-tested vehicle; inputting the mass matrix, the damping matrix and the stiffness matrix into a pre-constructed time history response calculation model; according to the mass matrix, the damping matrix and the stiffness matrix, the time history response of the to-be-tested vehicle is calculated through a time history response calculation model; wherein the time history response comprises a displacement vector, a speed vector and an acceleration vector. According to the embodiment of the invention, the calculation efficiency can be remarkably improved while the calculation precision is ensured, and the method is suitable for time-history response analysis of the key structure of the commercial vehicle under the complex dynamic load.

The present application relates to the field of power system control and power electronic energy storage technology, in particular to a generator set transient power compensation system and method thereof, the method comprising: collecting stator voltage, stator current, rotor angular velocity, power angle and DC bus voltage, and mapping into a generalized state vector; constructing a port-controlled Hamilton system model containing an initial interconnection matrix and an initial damping matrix based on preset physical parameters and obtaining a Hamilton energy function; taking partial derivative of the Hamilton energy function with respect to the generalized state vector, calculating an energy gradient vector, dynamically reconstructing a virtual interconnection matrix and a virtual damping matrix, analyzing control input and converting into a duty cycle command to send to an energy storage converter to perform transient power compensation; the system comprises a data acquisition module, a Hamilton energy controller and an energy storage converter; faster transient recovery, lower mechanical stress and more stable closed-loop response can be achieved.

The invention provides a workshop floor response spectrum calculation method adopting substructure analysis, and the method comprises the steps: solving a site response problem of a free field through a semi-analytical method based on the modulus and damping of the free field, and obtaining transmission boundary information; respectively calculating foundation impedance matrixes of transmission boundary information through a flexible volume method; calculating an upper structure matrix according to the foundation impedance matrix; the upper structure matrix comprises an upper stiffness matrix, an upper mass matrix and an upper damping matrix; constructing a motion equation according to the foundation impedance matrix and the upper structure matrix, and solving to obtain a frequency domain displacement response transfer function; and performing interpolation calculation on the frequency domain displacement response transfer function to obtain seismic response. According to the method, the calculation of the reaction spectrum is realized through a substructure analysis method for decomposing a linear soil-junction interaction analysis problem into a series of relatively simple subproblems, the calculation efficiency is improved, and the model construction period is shortened.

The invention belongs to the field of mechanical simulation analysis of composite material structural parts, and particularly discloses an equivalent mechanical modeling method of a variable-thickness composite material component, which comprises the following steps: acquiring a laying deformation measure, and determining deformation distribution of fiber cloth by using the laying deformation measure through a fishing net method; mapping the deformation distribution of the fiber cloth to a target structure grid by using a grid mapping method; constructing a numerical model of equivalent mechanical characteristics of the target structure grid by using a multilayer structure equivalent calculation formula; the equivalent mechanical characteristics comprise equivalent density, an equivalent stiffness matrix and an equivalent damping matrix; and determining a numerical value implementation program of the numerical value model, and performing equivalent mechanical analysis simulation on the variable-thickness composite material component by the numerical value model through the numerical value implementation program by adopting a finite element method. According to the method, the modeling accuracy of the variable-thickness composite material component is improved.

The application discloses a stiffness and damping optimization method, system, device, medium and product of a vehicle suspension based on a back propagation neural network, and relates to the technical field of vehicles. The method comprises the following steps: training a back propagation neural network based on a training set to obtain a trained back propagation neural network; extracting the trained back propagation neural network by adopting a Taylor expansion method and a finite difference method to obtain a matrix; constructing a nonlinear multivariate inter-axle stiffness-damping objective function based on the matrix; obtaining an input variable sequence and an output variable sequence of a vehicle; and optimizing the stiffness and damping of the vehicle suspension under a constraint condition by taking the function value of the nonlinear multivariate inter-axle stiffness-damping objective function as the target, so as to obtain an optimal stiffness-damping matrix and complete the stiffness and damping optimization of the vehicle suspension. The application can improve the driving smoothness and steering stability of the vehicle.

The present invention relates to a method for converting the vibration response of a cabin structure from onshore to underwater, comprising: S1, testing the structural mode under onshore support state, performing modal analysis to obtain the mass, damping and stiffness matrix M+M 支 、C+C 支 , K; S2, when the equipment in the onshore structure is running, test the structural vibration response and obtain the vibration displacement response u1 of the cabin structure onshore; S3, calculate the constant excitation vector F0 inside the structure; S4, additional displacement impedance Z for the bottom support 支 , additional displacement impedance Z of adjacent structures 邻 , additional displacement impedance of water Z 水 Calculate the following: S5. Calculate the inherent mass matrix M and damping matrix C of the compartment structure in the free state; S6. Calculate the underwater vibration displacement response u2 of the compartment structure when the same equipment within the compartment is operating. The present invention modifies the onshore compartment boundary conditions based on additional impedance, eliminating the differences in bottom support, structural truncation, and water environment between the onshore and underwater compartments, thereby enabling the estimation of underwater vibration of the onshore compartment.

The invention provides a method and system for predicting the elastic stability of an aircraft under the action of swing nozzle thrust, and the method comprises the steps: S1, constructing a one-dimensional finite element model, and obtaining an inertial measurement assembly position vector L and a swing nozzle thrust action point position vector R; s2, checking the one-dimensional finite element model to obtain a generalized mass matrix, a generalized stiffness matrix, a generalized damping matrix and a modal shape matrix; s3, establishing a state space model of a transfer function from the projectile body angular velocity to the swing nozzle swing angle response and the swing angle acceleration response, and obtaining a state equation; s4, establishing a generalized structure kinetic equation under the action of the thrust of the swing nozzle; s5, the generalized structure kinetic equation and the state equation are combined; and S6, evaluating the elastic stability of the aircraft. According to the method, stylized prediction of the elastic stability of the aircraft under the action of servo control and swing nozzle thrust can be realized, and the method has good rapidness and applicability.

The present application relates to the technical field of unit gap vibration test, and particularly relates to a unit gap vibration test method based on transient numerical simulation, which constructs a multi-degree-of-freedom dynamic model by acquiring unit structure parameters and operation parameters, adopts a genetic algorithm to globally optimize stiffness matrix and damping matrix parameters, and generates a high-precision dynamic model; integrates a thermal fluid coupling module in the model, dynamically corrects coupling weight factors in combination with a particle swarm optimization algorithm, generates a multi-physical-field non-steady-state coupling vibration response equation, and solves a Pareto optimal solution set to optimize gap parameters in combination with a multi-objective genetic algorithm. The present application realizes real-time evaluation of a vibration state and closed-loop output of a fault early warning signal. The present application solves the problem of insufficient characterization of non-steady-state multi-field coupling characteristics in the prior art, and provides high-precision technical support for online monitoring of rotating machinery.

The invention discloses a double-collision double-tuned damper for controlling transverse vibration of a floating fan tower, which is designed by the following steps of: constructing a single-column floating fan model; describing the movement of the single-column floating fan by adopting an Euler-Lagrange method and multi-body dynamics; and finally, substituting the kinetic energy and the potential energy into an Euler-Lagrange equation and carrying out linearization to obtain a mass matrix, a stiffness matrix and a damping matrix of the floating fan. DPDTMD design: coupling the kinetic energy and potential energy of the DPDTMD with the kinetic energy and potential energy of the floating fan, and finally obtaining a mass matrix, a stiffness matrix and a damping matrix of a motion equation of the single-column floating fan under the control of the DPDTMD through an Euler-Lagrange equation; dPDTMD parameter optimization includes the mass, rigidity and damping of the two dampers, the installation position of the limiting stopper and the collision rigidity and recovery coefficient of the collision material. On the basis of ensuring the control effect and robustness of the damper, the maximum stroke of the vibration absorber is limited.

The invention discloses a self-stabilization integrated direct-connection range extender rotor support strength calculation method, electronic equipment and a medium. The method comprises the following steps: calculating an engine output torque as a transmission system load according to parameters of an engine and a generator; determining an input load for rotor bracket strength calculation according to the load of the transmission system; calculating a rotor bracket stress result according to the input load; and determining the minimum fatigue safety coefficient of the rotor bracket according to the rotor bracket stress result. According to the method, the mass matrix, the damping matrix, the stiffness matrix, the system rotational inertia and the like of the whole transmission system and the mutual influence between the engine and the generator are considered, the complete period of the rotor bracket is fully considered, and the dynamic working load of the generator rotor bracket in each working cycle period is obtained; the dynamic load is obtained through calculation of dynamic simulation software, and the error of the simulation load is within an allowable range compared with that of the actually measured load, so that the simulation result is reliable.

The invention relates to the technical field of motor control, and discloses a disturbance compensation control method of a servo driver, which comprises the following steps: acquiring the operation state of a servo motor to construct a port controlled Hamiltonian kinetic model, and extracting an interconnection matrix and a dissipation matrix; constructing a fractional order superhelix expansion state observer, and obtaining an initial lumped disturbance estimated value; extracting Hamiltonian energy dissipation residual errors to carry out adaptive adjustment on the fractional order superhelix expansion state observer, and outputting a high-fidelity disturbance estimation value; constructing a nonlinear dynamic damping matrix based on the high-fidelity disturbance estimation value to perform energy shaping on the servo motor; and a matching equation is established in combination with the nonlinear dynamic damping matrix and the port controlled Hamiltonian kinetic model, and a compound control law is solved to generate a driving signal to control the servo motor. According to the method, the observer is dynamically adjusted by using the energy residual error, and the damping topology is reconstructed, so that high-frequency chattering and transient oscillation are inhibited, and the anti-interference capability of the system is improved.

The application discloses a kind of quick solution method for the transient dynamics of bogie containing crack bearing structure, belongs to bogie structure dynamic analysis technical field, it includes: obtaining the three-dimensional geometric model of bearing structure, crack geometric dimension and the position coordinate size of crack;Divide bearing structure finite element model, crack surface is carried out grid division processing;On the surface of bearing structure and crack surface, select the main degree of freedom node of finite element model;Substructure analysis is carried out to bearing structure finite element model;Obtain the mass matrix, damping matrix and stiffness matrix of bearing structure finite element model after reducing degree of freedom;Crack surface node is simulated by using one-way nonlinear stiffness unit and is constrained;Processing constraint boundary condition;Processing excitation load;Solve the second-order differential equation set of dynamics, judge whether crack surface occurs contact or not.The application can consider the opening and closing effect of crack, obtain the transient dynamics response of bearing structure containing crack under external load, and give consideration to solving precision and efficiency.

The invention provides a while-drilling electromagnetic wave resistivity logging inversion method based on a quasi-Newton method, and relates to the technical field of oil-gas exploration and development, and the method comprises the steps: collecting the actual measurement response data of an isotropic or anisotropic target stratum, constructing a three-layer TI medium stratum model, and determining the to-be-inverted parameters; performing global optimization by adopting a genetic algorithm, and outputting an optimal result as an initial value; constructing a quasi-Newton inversion model containing a regularization term, dynamically updating a Jacobian matrix by using a Broyden updating rule, introducing a diagonal adaptive damping matrix to replace a fixed damping factor, and adaptively adjusting the damping strength according to a parameter relative increment ratio; and inputting the initial value into the improved model for iterative operation until a termination condition is met. The method gets rid of manual experience dependence, avoids local extremum convergence, improves the inversion precision, reduces the number of iterations, improves the calculation efficiency, accurately inverts key parameters, meets the requirements of real-time geosteering engineering, and improves the oil-gas exploration and development efficiency.

The present application relates to the technical field of hoisting control, and discloses an automatic hoist coordination control system and method for ecological fish reefs, comprising a controller, which is internally provided with acquisition, calibration, reconstruction, mapping, admittance and execution modules. The method steps are as follows: firstly, the tension and length data are acquired to calibrate the virtual compliance center of the ecological fish reef, and the basic virtual damping matrix of the admittance model is initialized; then, the tension data are subjected to sequence fitting, the smooth tension value and tension gradient value are extracted, the tension change vector is generated and mapped into the spatial disturbance vector acting on the virtual compliance center; subsequently, the global slack risk factor is generated according to the tension feature evaluation, the damping matrix is dynamically reconstructed, and the spatial disturbance vector is substituted into the admittance model to calculate the pose correction vector. The present application can effectively dynamically offset the external disturbance of the ocean current field, prevent the flexible cable from being slackened and mechanically impacted and damaged, and ensure the stable deployment of the ecological fish reef.

This invention discloses a robust and precise control method for an X-rudder AUV. The method includes: obtaining the position, attitude, linear velocity, and angular velocity of the AUV hull, establishing a kinematic model, a dynamic model, and an X-distribution model to form a mathematical model of the X-rudder AUV; obtaining the current AUV position and route information in the horizontal and vertical planes, establishing a horizontal plane kinematic controller, and designing a vertical plane kinematic control law; designing a nonlinear disturbance observer to estimate and compensate for the unmodeled dynamics of the X-rudder AUV mathematical model and the vertical plane kinematic control law, generating a high-order sliding mode controller for the AUV; and distributing the control of the X-rudder based on the control outputs calculated by the AUV high-order sliding mode controller based on a damping matrix. This control method can effectively reduce the impact of model uncertainty and external disturbances on AUV control.

The application discloses a method and device for identifying equivalent physical stiffness and damping matrix of super high-rise building. First, the design parameters of the target super high-rise building are obtained, the static condensation method is used to condense the degrees of freedom of the target super high-rise building to obtain a corresponding low-degree equivalent system, and an equivalent mass matrix is obtained. Then, the physical time history signal measured at the condensation position is decoupled by using the complex second-order blind identification method to obtain a modal signal and a complex mode shape, and the improved Bayesian spectral density method is used to identify the modal parameters of the modal signal to obtain a frequency and a damping ratio. Finally, the equivalent physical stiffness and damping matrix are obtained by combining the obtained complex modal parameters with the equivalent mass matrix. The application adopts the degree of freedom condensation strategy, simplifies the system with high degree of freedom into an equivalent reduced model with less degree of freedom according to the actual measurement conditions and the structural response characteristics, and then evaluates the equivalent physical stiffness and damping matrix of the building based on the incomplete complex modal parameters.

The invention relates to a semi-submerged ship dynamic positioning control method considering draft change, which belongs to the technical field of semi-submerged ship dynamic positioning system control, and comprises the following steps of: calibrating hydrodynamic parameters of a plurality of semi-submerged ships under draft; acquiring the position and draught information of the semi-submerged ship; carrying out interpolation calculation on hydrodynamic parameters under the current draft; updating a mass matrix and a damping matrix in the mathematical model of the control system; acquiring position deviation information and environmental force feedforward information; solving a control force; thrust is distributed; and all the propellers send out the required thrust. According to the method, the continuous dynamic change of the draft during snorkeling of the semi-submerged ship can be considered, the control model is automatically adjusted in real time in combination with the draft measurement value, the positioning capability is achieved during dynamic change of the draft, and the safety of the semi-submerged ship during snorkeling operation is improved.

The invention provides a wind-induced vibration damping system for a sling and an optimization design method. The system comprises a sling separation frame, a viscous damping unit and a vibration reduction hammer unit. Multi-strand slings at the same height position are connected through the sling separation frame. The vibration reduction hammer unit comprises a vibration reduction hammer which is mounted on the sling separation frame; the viscous damping unit is arranged on the outer side of the multi-strand sling and is connected with the multi-strand sling; the method comprises the steps that motion equations of a system in the in-plane direction and the out-of-plane direction and a balance equation of a vibration reduction hammer are built, a characteristic equation is solved to obtain a complex characteristic value, and modal damping is obtained according to the solved equation; tuned masses, tuned damping coefficients and tuned rigidity of the vibration reduction hammers in the mass matrix, the damping matrix and the rigidity matrix, damping coefficients of the viscous damper and positions of the parameters in the matrixes are adjusted, and the parameters and the installation positions of the viscous damping unit and the vibration reduction hammers are optimized. The multi-strand long sling ultra-wideband multi-mechanism vibration control system has the advantages of being capable of achieving multi-strand long sling ultra-wideband and multi-mechanism vibration control and the like.

The present invention discloses a calculation method and system for the dynamic response of a reduction drive assembly under multi-source excitation, including the following steps: Based on the overall stiffness matrix, mass matrix, and damping matrix of the gear transmission system, establish the dynamic equation of the gear transmission system and calculate the dynamic flexibility matrix of the gear transmission system; establish a finite element model of the hub motor reduction drive assembly housing, and obtain the overall system dynamic model based on the finite element model of the assembly housing and the dynamic equation of the gear transmission system; calculate the dynamic gear meshing force as the mechanical excitation of the system; calculate the radial electromagnetic force of the permanent magnet synchronous motor under no-load and load conditions as the electromagnetic excitation of the system; apply the mechanical excitation and electromagnetic excitation to the gear transmission system, and combine with the dynamic flexibility matrix to calculate the vibration displacement response, velocity response, and acceleration response at each node of the system. The present invention can comprehensively and truly reflect the vibration characteristics of the reduction drive assembly during actual operation.

The invention discloses a construction method of an efficient dynamic time-history calculation model of a large-scale structure based on equivalent boundary recognition. The construction method comprises the following steps: step 1, establishing a finite element model of the structure; 2, extracting a stiffness matrix, a damping matrix and a mass matrix of the finite element model; 3, assuming a structure equivalent boundary condition and a polynomial coefficient according to the boundary shape of the structure model; 4, obtaining a corrected polynomial coefficient; 5, calculating a diagonal vector curve and a secondary diagonal vector curve according to the polynomial coefficient; step 6, the diagonal vectors are recombined into rigidity, damping and mass matrixes of equivalent boundary conditions; and step 7, generating an efficient calculation model. According to the method, small and medium seismic response data accumulated during operation of a large structure is utilized, a high-precision equivalent boundary condition recognition algorithm is established, and an optimized equivalent boundary condition is adopted to replace a huge foundation degree of freedom in a traditional model, so that a novel calculation model with both calculation efficiency and precision is constructed.