202 results about "Electromechanical coupling" patented technology

Disclosed in the present invention is a physics-informed neural network-based thermo-mechanical coupling analysis method for an inertial microsystem, the method comprising: S1, configuring material parameters and boundary conditions of an inertial microsystem, and establishing a thermo-mechanical coupling analysis model; S2, performing electro-thermal coupling analysis to obtain a temperature distribution of the inertial microsystem; S3, performing thermo-mechanical coupling simulation analysis to obtain a thermal stress distribution of the microsystem; S4, predicting temperature fields of the microsystem by means of a physics-informed neural network; S5, using the temperature fields as boundary conditions for mechanical simulation of the microsystem, obtaining mechanical properties such as stress and strain of the microsystem; and S6, performing electromechanical coupling simulation analysis to analyze the impact of structural deformation on various parameters of electrical performance. The present invention improves the solution accuracy of the neural network by means of an improved adaptive weighting strategy, combines a complete polynomial basis function with the neural network, and introduces an expanded basis function to reduce the state dimensionality, thus reducing computational costs and time, achieving accurate prediction of temperature fields of microsystems at multiple moments, and allowing for computation of the performance of microsystems under electro-thermal-mechanical multi-physics coupling.

The invention discloses a micro-cantilever geometric structure parameter inversion system, method and device, and belongs to the technical field of micro-electro-mechanical systems. According to the system, a dynamic model containing geometry, material and electromechanical coupling nonlinearity is constructed, a PINNs network fused with physical constraints is designed, a staged training optimization strategy is adopted, and efficient inversion of micro-cantilever geometric parameters is achieved. The core of the method is that a nonlinear kinetic equation is used as a constraint to be embedded into a neural network for training, experimental data and physical residual errors are combined to construct a composite loss function, and the problems that a traditional method neglects a nonlinear effect, depends on finite element simulation and is low in inversion precision are solved. The average relative error of inversion of the system is lower than 1%, which is obviously superior to that of a traditional method, and the method can be widely applied to MEMS device design, online detection and closed-loop control scenes.

The invention relates to the technical field of electromechanical coupling damage diagnosis, and discloses a wind and light storage system electromechanical coupling damage diagnosis method and system.The wind and light storage system electromechanical coupling damage diagnosis method includes the steps that according to geometric data, material attributes and load data of a welding point area, a finite element mechanical model is constructed, and stress distribution data is calculated; according to the environment data and the electrochemical data, a corrosion kinetic model is constructed, and corrosion product parameters are obtained; according to the corrosion product parameters, an elastic modulus degradation model is established, and an inherent frequency degradation value and vibration mode displacement are obtained; performing vibration response analysis on the junction box according to the inherent frequency degradation value and the vibration mode displacement to obtain a stress concentration coefficient; and inputting the electrical parameter variation and the stress concentration coefficient into a damage failure evaluation model to obtain a damage failure evaluation result of the electrical connection point. Through the multi-dimensional coupling model and the dynamic parameter closed-loop feedback mechanism, the electromechanical coupling damage assessment accuracy is effectively improved, and the operation safety and the operation and maintenance efficiency of the wind and light storage system are improved.

The invention relates to the technical field of power grid stability analysis, in particular to a mechanical vibration micro-grid electromechanical coupling system stability analysis method, which comprises the following steps of: detecting a tooth surface contact radius, a relative speed and a Young modulus to generate a contact stiffness initial value, correcting nonlinear stiffness by interval difference, and calculating the stability of a micro-grid electromechanical coupling system. The method comprises the following steps: calculating a coupling response vector by combining rotor displacement and bearing clearance, inputting a Lyapunov exponent method to solve an exponent vector, constructing a model length ratio to detect derivative characteristics, extracting a multidimensional state vector in a positive value period and the coupling response vector to generate a compensation action, and constructing an FPGA simulation path injection disturbance execution error feedback back-transmission fuzzy control algorithm. According to the method, a contact stiffness dynamic correction and nonlinear difference method is introduced, six-degree-of-freedom displacement and bearing clearance parameters are combined, an electromechanical coupling model is established, a stability boundary is recognized through Lyapunov regression, a critical state is detected through derivative features, and multi-dimensional state vector fuzzy control compensation is fused. And the response and the immunity are optimized by combining FPGA simulation and a disturbance mechanism.

The invention provides a multi-mode triple composite vibration energy acquisition device based on a frequency division technology and a self-powered sensing system. The multi-mode triple composite vibration energy acquisition device comprises a shell, an electromagnetic power generation element, an elastic piezoelectric power generation element and a friction nano power generation element, the electromagnetic power generation element comprises a magnet vibrator and a coil, electromechanical coupling control switches are arranged on the two sides of the magnet vibrator respectively, and each electromechanical coupling control switch is connected with one side of the magnet vibrator through a first elastic unit and an inerter which are connected in parallel. A coil is arranged on the shell on the outer side of the magnet vibrator, and electric energy is generated through reciprocating motion of the magnet vibrator; a friction nanometer power generation element is arranged between the magnet vibrator and the electromechanical coupling control switch, and electric energy is generated by changing the distance between the magnet vibrator and the electromechanical coupling control switch; and an elastic piezoelectric power generation element is arranged between the electromechanical coupling control switch and the wall surface of the shell. Automatic switching of electromagnetic power generation, friction power generation and piezoelectric power generation can be realized under excitation of different frequencies.

The invention belongs to the field of wind tunnel experiments in a hypersonic flow field environment, and discloses a multi-degree-of-freedom high-frequency motion simulation device for an aircraft dynamic stability test and a calculation method for realizing an actuation angle. According to the technical method, calculation is carried out on the basis of an electromechanical coupling equation, determined by electrical parameters and mechanical parameters, of a piezoelectric material. Modeling can be carried out according to a piezoelectric equation to obtain a calculation method between the voltage applied by the piezoelectric actuator and the pitching and yawing actuation angles of the device, so that the excitation effect of the device in the ground test process can be accurately controlled and predicted. The method is not only suitable for pitching and yawing two-degree-of-freedom actuation calculation, but also can be used for calculating the actuation angle of a three-axis degree-of-freedom experimental device added with rolling drive through coordinate transformation under the condition of adding parameters such as rolling angular velocity and the like in the face of the three-axis degree-of-freedom experimental device added with rolling drive. At present, according to a calculation method based on the device, calculation is carried out only by considering the degree of freedom of the pitching axis and the yawing axis.

The invention relates to the technical field of data processing, in particular to a gearbox service life evaluation method and system. The method comprises the following steps of collecting shaft current of a gearbox under an electromechanical coupling working condition, carrying out current characteristic association on each bearing, and generating a current characteristic sequence of each bearing; according to the current characteristic sequence of each bearing, judging the main circulation path and branch of the current between a gear meshing pair in the gear box, and carrying out electric corrosion damage evaluation to generate a bearing-tooth surface electric corrosion damage ratio; calculating a fatigue life reduction coefficient of the part according to the bearing-tooth surface electric corrosion damage ratio, and performing dynamic linear damage accumulation treatment to obtain a fatigue damage contribution value of each part in a period; evaluating the service life of the gearbox according to the fatigue damage contribution value of each part in the cycle, and generating the residual life percentage of the gearbox. According to the method, the residual life of the gearbox under the electromechanical coupling working condition is accurately predicted through collaborative evaluation of the electric corrosion damage and the vibration amplification effect.

The invention discloses an online suppression method, device and equipment for an electromechanical coupling effect of a radio frequency superconducting cavity, and a medium. The method comprises the following steps: obtaining an original cavity voltage Vc * and an original forward voltage Vf * of the radio frequency superconducting cavity; carrying out calibration and normalization processing on the original cavity pressure Vc * and the original forward voltage Vf *; the normalized cavity voltage Vc and the forward voltage Vf during electromechanical oscillation are screened out, a differential equation is established, and the dynamic detuning delta f of the radio frequency superconducting cavity during electromechanical oscillation is calculated; based on the normalized cavity pressure Vc and the dynamic detuning delta f, identifying a transfer function of a radio frequency superconducting cavity mechanical mode by using a system identification method; establishing a coupling system characteristic equation according to the transfer function of the cavity mechanical mode, the transfer function of the radio frequency superconducting cavity and the transfer function of the low-level system controller, and solving the characteristic equation to find out stability boundaries under different parameter conditions; and optimizing closed-loop control parameters according to the stability boundary, and realizing online suppression of the electromechanical coupling effect.

The invention relates to the technical field of resonators, and discloses an MEMS resonator and a composite preparation method thereof.The composite preparation method of the MEMS resonator comprises the steps that a highly-doped first monocrystalline silicon layer is formed to serve as a supporting substrate; forming a piezoelectric material layer on the first monocrystalline silicon layer; forming a seed layer on the piezoelectric material layer at a first set rate, epitaxially forming a main body layer on the seed layer at a second set rate, and compounding the seed layer and the main body layer to form a highly doped second monocrystalline silicon layer; deep reactive ion etching is carried out on the laminated structure layer constructed based on the first monocrystalline silicon layer, the piezoelectric material layer and the second monocrystalline silicon layer, a resonator body, a connecting beam and an anchoring part are formed, and the resonator body is arranged in a suspended mode and connected with the anchoring part through the connecting beam. According to the invention, the electromechanical coupling efficiency and the quality factor of the MEMS resonator are improved, and the temperature stability of the MEMS resonator is ensured.

The invention discloses an acoustic wave filter based on an AlN / AlGaN superlattice structure and a preparation method of the acoustic wave filter, and relates to the technical field of filters, the acoustic wave filter comprises a superlattice main body, and is characterized in that the superlattice main body comprises a substrate and a piezoelectric superlattice layer located on one side of the substrate; wherein the substrate is a Si substrate, a sapphire substrate or a SiC substrate; the piezoelectric superlattice layer is a composite alternating layer of an AIN layer and an Al < x > Ga < 1-x > N layer, and x is a constant greater than 0. The invention has the effects of reducing strain, improving compatibility and reliability, being suitable for high-frequency operation and remarkably improving electromechanical coupling performance.

The invention discloses a mine electromechanical equipment operation safety situation assessment method and system, and relates to the technical field of mine electromechanical equipment safety monitoring and assessment, and the method comprises the following steps: building an electromechanical coupling time frequency observation layer, continuously obtaining the dynamic characteristics of tension data, displacement data, current data and torque data, generating a modal fingerprint baseline based on conjoint analysis; coherent decomposition is carried out under the support of the modal fingerprint baseline, the modal drift speed is calculated, and the risk window with the driving frequency gradually approaching is identified, so that the frequency evolution trend is revealed in advance. According to the method, an electromechanical coupling time-frequency observation system is constructed, a modal fingerprint baseline is extracted, the resonance risk is recognized in advance in combination with coherent decomposition and anti-fact playback, energy dissipation is achieved through peak shifting driving and structural damping, and finally, phase traction and a phonon band gap structure are used for rapid vibration extinguishing, so that a complete dynamic regulation and control closed-loop system is formed.

The invention relates to a filter integrating a fundamental wave resonator and a harmonic wave resonator and a manufacturing method of the filter, the fundamental wave resonator and the harmonic wave resonator are resonators in a thickness extension vibration mode, the fundamental wave resonator and the harmonic wave resonator are integrated on a single chip in a single crystal mode, the stack acoustic phase length hph of the fundamental wave resonator and the harmonic wave resonator is close to pi n, n is a harmonic order, and the acoustic phase lengths of the dielectric layers of the fundamental wave resonator and the harmonic wave resonator approach to pi (n-1). Dielectric layers with different thicknesses are arranged in a fundamental wave resonator area and a harmonic wave resonator area, the acoustic phase length of the dielectric layers of the fundamental wave resonator and the harmonic wave resonator is pi (n-1), the fundamental wave resonator and the harmonic wave resonator are integrated on a single chip, and therefore a wider frequency range and more suitable electromechanical coupling are achieved.

Techniques for improving acoustic resonators and resonator structures are disclosed, including filters, oscillators and systems that may include such devices. A bulk acoustic wave (BAW) resonator may comprise a substrate. The bulk acoustic wave (BAW) may further comprise a plurality of piezoelectric layers including first, second, third and fourth piezoelectric layers acoustically coupled with one another and arranged over the substrate. The first, second, third and fourth piezoelectric layers may have respective piezoelectric axis orientations. The first, second, third and fourth piezoelectric layers may have respective thicknesses. Electromechanical coupling of the bulk acoustic wave (BAW) resonator may, but need not be limited.

The present invention discloses a thermomechanical coupling analysis method for an inertial microsystem based on a physical information neural network, comprising: S1, setting the material parameters and boundary conditions of the inertial microsystem and establishing a thermomechanical coupling analysis model; S2, obtaining the temperature distribution of the inertial microsystem through electrothermal coupling analysis; S3, obtaining the thermal stress distribution of the microsystem through thermomechanical coupling simulation analysis; S4, predicting the temperature field of the microsystem through a physical information neural network; S5, using the temperature field as the boundary condition for the mechanical simulation of the microsystem to obtain the mechanical properties such as stress and strain of the microsystem; S6, performing electromechanical coupling simulation analysis to analyze the influence of structural deformation on various parameters in the electrical properties. The present invention improves the solving accuracy of the neural network through an improved adaptive weight strategy, combines the complete polynomial basis function with the neural network, introduces the expanded basis function to reduce the state dimension, reduces the computational cost and time, realizes the accurate prediction of the temperature field of the microsystem at multiple moments, and calculates the performance of the microsystem under the coupling of electrothermal and mechanical multi-physical fields.

The invention provides a concrete-filled steel tube interface stripping defect positioning and detecting system, and relates to the technical field of structure monitoring. Piezoelectric ceramic sensors are installed on the outer wall of a steel tube of a concrete-filled steel tube member and the lower surface of an annular plate, an impedance analyzer is used for applying alternating voltage excitation, and the stripping defect of the concrete-filled steel tube interface is detected by means of the positive and negative piezoelectric effects of piezoelectric ceramic materials. And enabling the sensor to output an electromechanical coupling admittance frequency curve. Admittance data are processed and converted into picture data through a computer, the picture data are input into a convolutional neural network model, and accurate positioning of the concrete filled steel tube member interface stripping defect is achieved through feature extraction and classification of a convolutional layer, a pooling layer and a full connection layer. The system is particularly suitable for detecting local initial damage in a high-frequency range, has the characteristics of simplicity and convenience in operation, quick response and high visibility, and provides a quick and accurate solution for real-time detection of the concrete-filled steel tube member.

The invention relates to the field of motor and gear transmission systems, in particular to a method for optimizing design parameters of a transmission gear in an electric drive system.The method includes the steps that firstly, a two-dimensional finite element model of a permanent magnet synchronous motor is established, rotor stepped skewed slots and material magnetic saturation characteristics are accurately simulated, and an external characteristic MAP is generated; then calculating electromagnetic force density based on a Maxwell stress tensor method, mapping the electromagnetic force density to a multi-body dynamic model to construct a transverse coupling model, extracting an ECE reduced-order model based on a permanent magnet synchronous motor two-dimensional finite element model, forming a torsional vibration model in combination with a control algorithm, integrating a rigid-flexible coupling mechanical system, and establishing an electromechanical-rigid-flexible coupling model; and finally, through sensitivity analysis and a response surface model, with vibration acceleration and torsion amplitude as targets and gear strength as constraints, a Pareto optimal solution is solved by adopting a genetic algorithm, electromechanical coupling simulation precision is greatly improved, system vibration is effectively reduced, gear transmission reliability is enhanced, and the method is suitable for design of a high-dynamic-performance electric drive system.

The invention relates to a prospective control method of a multi-axis linkage machine tool in the field of intelligent manufacturing, which comprises the following steps: by analyzing the time difference distribution of each axis in a compensation time sequence, establishing a dynamic compensation matrix of multi-axis linkage, the matrix comprising the advanced starting time and speed regulation coefficient of each axis in different motion stages, determining personalized motion control parameters of each axis; according to the updated delay characteristic data and the curvature radius information of the track corner, the position deviation trend of each axis in the corner machining process is predicted, whether the motion time sequence of each axis needs to be adjusted or not is judged by comparing the deviation degree of the predicted position and the theoretical track, and an optimized multi-axis cooperative motion instruction is obtained; and the optimized multi-axis cooperative motion instruction is input into a servo controller of each axis, an actual position feedback signal of each axis is monitored at the same time, and the response consistency of each axis is ensured by calculating the real-time deviation value of an actual track and a theoretical track and dynamically correcting compensation parameters in an electromechanical coupling delay model.

The invention relates to an electromechanical coupling rotor system starting and vibration suppression method based on fuzzy PID control, and belongs to the field of electromechanical coupling rotor systems. According to the method, an 8-degree-of-freedom rotor system mechanical dynamics model and an equivalent motor model are established through a finite element method, an electromechanical coupling rotor simulation model is established based on Matlab / Simulink, and then a fuzzy PID control module is established to be assembled with an electromechanical coupling rotor system. Finally, simulation analysis is conducted on the electromechanical coupling rotor assembled with the fuzzy PID control module and the normal PID control module, and the result shows that the fuzzy PID control module can effectively shorten the starting response time of the rotor system and the vibration amplitude during stable operation.

The invention discloses a random control method of a three-stable-state piezoelectric cantilever beam structure energy harvester, and belongs to the field of energy harvesters. The implementation method comprises the following steps: introducing white noise by considering random excitation in an environment, establishing an electromechanical coupled strong nonlinear three-stable state energy harvester model, and carrying out dimensionless processing on the energy harvester model to obtain an electromechanical coupled strong nonlinear three-stable state energy harvester dimensionless model; based on the acquired displacement data and voltage of the three-stable-state energy harvester, establishing a model equation of the three-stable-state energy harvester by using dimensionless coefficients zeta, theta, km (m = 1, 2, 3) and D in an electromechanical coupling equation of the strong nonlinear three-stable-state energy harvester by using a sparse identification method of a nonlinear power system; based on a strong nonlinear three-stable-state energy harvester electromechanical coupling equation established by using an SINDy method and system response, an optimal control law alpha is calculated by using a model prediction control method, a control signal is applied through a Buck-boost circuit according to the optimal control law alpha, random control of the three-stable-state piezoelectric cantilever beam structure energy harvester is realized, and the output power of the energy harvester is increased.

The invention belongs to the technical field of power distribution network hot-line work robots, and provides an electromechanical coupling system multi-parameter collaborative optimization method based on a GRPO reinforcement learning algorithm, and the method comprises the steps: obtaining multi-parameter operation data of an electromechanical coupling system in an operation process; carrying out preprocessing on the obtained operation data; constructing a state vector based on the preprocessed operation data; constructing a GRPO reinforcement learning collaborative optimization model based on a GRPO reinforcement learning algorithm; inputting the state vector into a GRPO reinforcement learning collaborative optimization model; and the GRPO reinforcement learning collaborative optimization model obtains an optimization strategy through interactive learning with the electromechanical coupling system. The method is based on a reinforcement learning framework, so that the optimization strategy can adapt to parameter drift caused by system operation condition change, environment interference and part aging in real time, and the robustness of the optimization effect is kept.

The invention relates to an electromechanical coupling characteristic-based electric drive system double-layer active torsional vibration suppression method, which belongs to the technical field of electric automobile motors and comprises the following steps of S1, establishing a permanent magnet synchronous motor mathematical model, an electric drive system helical gear pair kinetic model and a gear transmission lumped parameter model; s2, establishing an upper-layer state feedback control method based on pole assignment, including establishing a transmission system dynamic state space equation, a state observer and a state feedback controller; and S3, establishing a lower torsional vibration suppression method based on active-disturbance-rejection control. According to the invention, voltage deviation generated by nonlinearity of the inverter is compensated, and current harmonics and torque fluctuation are reduced; according to the invention, the damping ratio at the pole corresponding to the inherent frequency which easily causes resonance is improved, the low-frequency torsional vibration is reduced, and the time for reaching the steady state is shortened; according to the invention, current harmonics and torque ripples are reduced, and high-frequency torsional vibration of an electric drive system is reduced.

The invention discloses a high-performance dielectric elastomer film, a driver capable of being driven at low voltage and a preparation method of the driver. According to the preparation method of the high-performance dielectric elastomer film, customization and balance of mechanical properties and electrical properties of a dielectric elastomer are realized by regulating and controlling the proportion of a chemical cross-linking agent, a high-polarity physical cross-linking agent and a monomer; according to the preparation method of the driver capable of being driven at the low voltage, a dielectric elastomer film and a flexible electrode are stacked through an optimized dry stacking method, the dielectric elastomer driver of a multilayer structure is constructed, and the driver has excellent performance under the low driving voltage. The preparation method has the potential of large-batch and large-scale production, and the prepared dielectric elastomer film has low Young modulus and enhanced strain hardening effect, can avoid electromechanical coupling instability, has high dielectric constant, has large-area strain in a low electric field, and can be used for preparing a dielectric elastomer film. The resulting dielectric elastomer driver can have a blocking force of 0.8 N and an energy density of 80 J / kg at a voltage of 500 V.

The invention discloses a lithium niobate acoustic superlattice bulk acoustic wave resonator device based on an inclined domain structure and a design method thereof.The bulk acoustic wave resonator device comprises an upper surface electrode, a lithium niobate acoustic superlattice and a lower surface electrode which are sequentially stacked from top to bottom, the lithium niobate acoustic superlattice comprises positive domain regions and negative domain regions which are alternately arranged, and the positive domain regions and the negative domain regions are alternately arranged. And the positive domain region and the negative domain region are inclined domains. The invention also provides a design method of the bulk acoustic wave resonance device, which comprises the following steps of: firstly, acquiring simulation parameters through numerical simulation, and then designing different cut types of lithium niobate acoustic superlattices with positive domain regions and negative domain regions which are periodically and alternately arranged and inclined structures according to the simulation parameters; and finally, respectively selecting proper electrodes on the upper surface and the lower surface of the lithium niobate acoustic superlattice to form the bulk acoustic wave resonator. The bulk acoustic wave resonator is simple in structure, and has more working resonance modes and a higher electromechanical coupling coefficient.

System and methods for a hollow-disk radial-contour mode resonator structure. The hollow disk reduces the dynamic mass and stiffness of the structure. Since electromechanical coupling Cx / Co goes as the reciprocal of mass and stiffness, the hollow disk structure has a considerably stronger electromechanical coupling than a solid one at the same frequency, and thus raises Cx / Co without excessive gap-scaling. Several embodiments of hollow disk resonators are detailed, including asymmetric and symmetric disk configurations.

The application provides a detection system for interface peeling defects of a steel shell inner wall and concrete, which comprises a detection device, and the detection device comprises a signal generator, a signal amplifier, a plurality of piezoelectric material sheet assemblies, a signal acquisition assembly and a data analysis processor which are electrically connected in sequence; the plurality of piezoelectric material sheet assemblies are attached to the outer wall of the steel shell at intervals to form an electromechanical coupling system. The piezoelectric material sheet is arranged on the outer wall of the steel shell of the steel shell concrete component as a driver and a sensor at the same time, the electromechanical coupling impedance spectrum of the piezoelectric material is measured in a self-generating and self-receiving mode, the abnormal value of the electromechanical coupling impedance spectrum is analyzed, the RMSD of the electromechanical coupling impedance spectrum of the measuring point and the reference measuring point is calculated, the sensor position corresponding to the abnormal signal is screened out, and thus the accurate positioning and range estimation of the interface peeling defects are realized.

The invention discloses a fault detection method for an explosion-proof and intrinsic safety type hybrid electric appliance switch based on artificial intelligence, and relates to the technical field of intelligent operation and maintenance of power equipment, and the method comprises the following steps: S1, synchronously collecting multi-modal sensing data during the operation of the hybrid electric appliance switch through a plurality of intrinsic safety type sensors synchronously driven by a unified clock source; the multi-mode sensing data at least comprises electrical sensing data and mechanical vibration sensing data. According to the fault detection method for the flame-proof and intrinsic safety type hybrid electric appliance switch based on artificial intelligence, through a multi-mode synchronous acquisition and deep fusion architecture, the technical problem that fault feature acquisition is incomplete and asynchronous under strict explosion-proof constraints is effectively solved. Through a processing mechanism of edge calculation and cloud collaboration, accurate capture and intelligent screening of electromechanical coupling features are realized, the accuracy and reliability of fault diagnosis are improved by combining dual verification and a confidence fusion decision model, and effective technical support is provided for early fault early warning.

Mechanically and piezoelectrically anisotropic polymer fibers may be formed by spinning a polymer solution or gel that includes a high molecular weight crystallizable polymer and a liquid solvent. The solvent may be configured to interact with the polymer to facilitate chain alignment and, in some examples, create a higher crystalline content within the spun fibers. The polymer solution may also include a low molecular weight additive. The high and low molecular weight polymers may each be characterized by a bimodal molecular weight distribution where the molecular weight of the additive is less than the molecular weight of the crystallizable polymer. The polymer(s) and the additive(s) may be independently selected from vinylidene fluoride, trifluoroethylene, chlorotrifluoroethylene, hexafluoropropene, vinyl fluoride, etc. The spun fibers may be oriented, annealed, poled, and woven or laminated to form a polymer thin film having a high elastic modulus and a high electromechanical coupling factor.

The application discloses a dynamic reliability evaluation method for a permanent magnet planetary gear transmission system, and belongs to the technical field of reliability analysis of electromechanical coupling transmission systems. The method is characterized in that: firstly, the service process of the system is divided into stages, and a random variable model is established; based on the wear evolution relationship, parameters of each stage are obtained through parameter mapping; then, stage high-fidelity unified electromechanical dynamics solving is performed, and frequency-related characteristic indexes are extracted; a multi-failure mode limit state vector is constructed, and a stage failure event is defined; on this basis, a multi-response Gaussian process proxy model is used for fitting and iterative updating of the limit state function through stage-by-stage active learning; the U function is used for initial screening of candidate samples, EFF is calculated and sorted, and a new sample point is selected according to the Top-K criterion to update the proxy model, until the convergence criterion is met; finally, the dynamic failure probability of the system is calculated by using the updated proxy model. The application realizes efficient and accurate evaluation of the failure probability of multiple failure modes, reduces the calculation cost, and improves the engineering applicability.

The invention belongs to the technical field of functional materials, and particularly relates to a 1-3 type lead metaniobate piezoelectric composite material and a preparation method and application thereof. The composite material takes lead metaniobate ceramic with a tungsten bronze structure as a one-dimensional piezoelectric phase and takes epoxy resin as a three-dimensional polymer phase. The ratio [lambda] / T of the transverse periodic dimension ([lambda]) of the ceramic column to the thickness (T) of the composite material is 0.1-0.6. The preparation method is characterized in that the ceramic column array is formed through precise cutting, cutting parameters are controlled to achieve the lambda / T ratio, and then resin encapsulation, curing, polishing and electrode preparation are conducted. According to the invention, the electromechanical coupling performance and stability of the composite material at ultrahigh temperature are synergistically improved by selecting the lead metaniobate ceramic with high Curie temperature and combining specific lambda / T structural parameters. The obtained material can still keep good performance at 350 DEG C, the maximum thickness electromechanical coupling coefficient kt can reach 0.35, and the material is suitable for high-temperature acoustic logging and underwater acoustic receiving transducers.

A lock device comprising an input member rotatable about an input axis; an output member rotatable about an output axis; an electromechanical coupling device configured to adopt an uncoupled state, where rotation of the input member about the input axis is not transmitted to a rotation of the output member about the output axis, and a coupled state, where rotation of the input member about the input axis can be transmitted to a rotation of the output member about the output axis; an electric control system configured to control the coupling device to switch between the uncoupled state and the coupled state; and a sensor in signal communication with the control system, the sensor being configured to generate a position signal indicative of a position of the output member about the output axis. A lock system comprising a lock device is also provided.