21 results about "Internal resonance" patented technology

The invention discloses a double-cantilever-beam piezoelectric vibration energy collector based on an annular steady state, which comprises a piezoelectric transducer, an elastic cantilever beam, a magnet and a base, after the piezoelectric transducer is mounted on the elastic cantilever beam to form a double-layer composite cantilever beam, the magnet is mounted at the free end of the double-layer composite cantilever beam, nonlinear coupling is carried out through repulsive magnetic force, and the piezoelectric transducer is connected with the base. The two-dimensional annular potential well structure with the adjustable potential well is formed, and the energy collector can easily trigger large-amplitude inter-well movement through the potential well structure. Through the nonlinear coupling induced internal resonance effect, inter-well energy transfer and two-dimensional potential well modulation are realized, and vibration energy can be efficiently captured in a broadband without a large amount of energy input or a complex structure. According to the design, the collection efficiency of low-frequency, low-intensity and multi-direction environment vibration energy in a wide working bandwidth is good.

The invention provides a medium loading resonant cavity analysis method based on a volume-surface integral equation, and belongs to the technical field of resonance characteristic numerical analysis. According to the method, an internal resonance generalized eigenvalue equation based on a body-surface integral equation and internal resonance factors representing internal resonance attributes of body and surface current characteristic modes are defined, so that accurate solution of a unique internal resonance mode is realized; the method avoids the problem that the traditional characteristic value method is difficult to directly solve the internal resonance mode and the mode field of the metal cavity with the aperture after the medium is loaded, is suitable for the loading medium and the metal cavity with any shape and placement relation, and achieves accurate modeling through the volume-surface mixed grid on the premise of guaranteeing the solving precision. Compared with a finite element method, the method has lower modeling complexity.

The invention belongs to the technical field of converter resonance suppression, and particularly relates to an energy storage system converter resonance suppression method and system. According to the method, the resonance problem can be quickly positioned, targeted measures can be taken, the fluctuation time of the energy storage system is shortened, the regulation and control precision is improved, the dynamic change of the energy storage system and the power grid can be adapted by utilizing historical data of the evaluation time period and dynamic coefficient adjustment of the power grid operation state, and the method has relatively high adaptive capacity; the coupling effect of the internal resonance characteristics of the energy storage system and the external power grid state is comprehensively considered, and through fusion of two regulation and control coefficients, internal and external collaborative optimization of the energy storage system is realized, the resonance occurrence probability is reduced, a resonance suppression strategy can be continuously optimized, and the reliability and stability of long-term operation of the energy storage system are improved. By effectively inhibiting the resonance phenomenon, energy loss and equipment damage caused by resonance are reduced, the service life of the energy storage system is prolonged, stable operation of a power grid is guaranteed, and efficient utilization of the energy storage system is promoted.

This invention relates to the field of wave energy generation, and more particularly to a dual-frequency high-efficiency energy harvesting method for a spring pendulum wave energy generator. The energy harvesting method includes the following steps: the spring pendulum wave energy generator enters the working state and directly contacts seawater, moving in undulating motion with the waves; the two directional degrees of freedom of the spring pendulum wave energy generator are adjusted; the spring pendulum wave energy generator uses a swing arm to adjust the resonant frequency of the oscillation degree of freedom of the float; the spring pendulum wave energy generator uses the resonant frequency of the hemispherical float and the spring-adjusted float along the radial degree of freedom of the long swing arm; a spring is added to the swing arm to make it a nonlinear spring pendulum structure, and its internal resonance characteristics are used to realize the mutual switching of the float's kinetic energy between the oscillation and radial degrees of freedom.

The application discloses a kind of based on independent parametric internal resonance principle's shock absorber and shock absorbing method, the shock absorber includes: power transmission wire;Several cantilever shock absorbers are fixed on the power transmission wire by fastening screw and nut;The spatial position of the power transmission wire and cantilever shock absorber is orthogonal, and the ratio of natural frequency is preset value;The cantilever shock absorber and power transmission wire constitute independent parametric internal resonance system, and the modal damping of cantilever shock absorber is obtained by simulating the independent parametric internal resonance system under the condition that the ratio of natural frequency is preset value and the shock absorbing effect of cantilever shock absorber is best, so as to adjust the modal frequency of cantilever shock absorber.The application utilizes independent parametric internal resonance principle, realizes the substantial absorption of power transmission line vibration energy to achieve the purpose of passive shock absorbing.

The present invention relates to a broadband ventilation and sound insulation window unit structure and its application. The broadband ventilation and sound insulation window unit structure includes an internal resonance cavity (1), a hollow tube (2), and a thin-walled outer shell (3). The outer wall of the hollow tube (2) is fixedly connected to the internal resonance cavity (1), and the outer edge of the internal resonance cavity (1) is sleeved with the thin-walled outer shell (3). The internal resonance cavity (1) includes a plurality of hollow cylinders with the same structure and size that are stacked up and down on the outer wall of the hollow tube (2). The outer edges of the bottoms of each layer of hollow cylinders are respectively provided with circumferentially structured horizontal partition plates (11). The circumferential partition partitions (4) and radial partition partitions (5) for dividing each layer of resonance cavities into multiple resonance spaces are provided on each layer of horizontal partition plates (11). Compared with the prior art, the present invention has the advantages of improving the sound insulation effect, having a wide working frequency band, being able to improve the effective sound absorption while achieving high-efficiency sound insulation, and having a wide application range, etc.

The application discloses a flexible mechanical arm main resonance control method based on nonlinear feedback and time delay feedback, and mainly comprises the following steps: discretizing the transverse deformation of the flexible mechanical arm by using the assumed mode method to obtain the vibration equation of the flexible mechanical arm; introducing a linear feedback control term, a nonlinear feedback control term and a time delay feedback control term to constitute a control signal model of a vibration absorber; constructing the control signal model of the vibration absorber; establishing a flexible mechanical arm system vibration control model of the vibration absorber by using Kane equation; applying a multi-scale method to solve the approximate analytical solution of the system vibration equation to obtain a single mode solution and a double mode solution of the system steady-state response; and finally, under the condition that the flexible mechanical arm system vibration control model of the vibration absorber coexists with the internal resonance condition and the main resonance condition, the main resonance of the flexible mechanical arm is controlled, and the mode amplitude of the first order mode of the flexible mechanical arm in the main resonance is well inhibited.

The present invention discloses a calculation method for equivalent resistance damping and equivalent natural frequency of an internal resonance piezoelectric energy harvesting system. An L-shaped piezoelectric vibration energy harvesting system and its corresponding coordinate system are built. The L-shaped piezoelectric vibration energy harvesting system includes an L-shaped vibration energy harvester and a piezoelectric energy harvesting circuit provided with a load resistor R. A piezoelectric energy harvesting equivalent circuit is constructed according to the piezoelectric energy harvesting circuit; all parameters in the L-shaped piezoelectric vibration energy harvesting system are obtained, and through adjustment, the ratio of the first-order and second-order natural frequencies of the system is made equal to 1:2; in combination with the coordinate system, a force-electric coupling control equation of the two-degree-of-freedom L-shaped piezoelectric vibration energy harvesting system is constructed; the multi-scale method is used to solve the first-order and second-order equivalent damping ratios and the first-order and second-order equivalent natural frequencies in the force-electric coupling control equation. Effect: Quantitatively measure the influence degree of the load resistor on the natural frequency and damping ratio in the nonlinear internal resonance theoretical model.

Frequency stabilization is provided in a microelectromechanical systems (MEMS) oscillator via tunable internal resonance (IR). A device comprises a MEMS resonator comprising a stepped-beam structure that is a thin-layer structure. The resonator may be configured to implement IR. The stepped-beam structure may be configured to provide flexibility to adjust modal frequencies into a n:m ratio, wherein n and m are integers. The thin-layer structure provides frequency tunability by controlling the mid-plane stretching effect with an applied DC bias. The thin-layer structure compensates for a frequency mismatch from a n:m ratio due to a fabrication error. The MEMS resonator may be an oscillator.

The present invention discloses an electromagnetic induction micro-machined magnetic sensor with internal resonance coupling and a preparation method. The electromagnetic induction micro-machined magnetic sensor comprises a first resonant structure, a second resonant structure, and a coupling beam between the two resonant structures. The present invention connects two resonant structures with an integer ratio of resonant frequencies via the coupling beam to form an internal resonance coupling resonant system. The system can transfer overloaded nonlinear energy to the other resonant structure through the internal resonance principle after a resonant structure reaches resonant nonlinearity, causing it to resonate. Thus, the performance of the magnetic sensor is improved by superimposing the electromagnetic induction magnetic signals output by the two resonant structures, overcoming the limitation of traditional electromagnetic induction magnetic sensors with a single resonant structure that it is difficult to improve device performance by increasing the overload of the electrostatic driving force.

The invention provides an irregular material complex dielectric constant measuring method based on a resonant cavity, and belongs to the technical field of microwave material electromagnetic parameter testing. The method comprises the following steps: firstly, analyzing a resonance mode of an air resonant cavity based on a characteristic mode, and determining an internal resonance mode by solving minimum internal resonance factors of different modes; calculating an electric field E and a magnetic field H of a resonance mode under different dielectric constants of the sample when the sample in the same shape is loaded, and further solving a corresponding minimum mode factor when the mode resonates so as to obtain a relative dielectric constant to be measured; and meanwhile, by utilizing the definition of a quality factor, substituting the relative dielectric constant, and finally solving to obtain the loss tangent of the sample. According to the method, the full-wave characteristic of the characteristic mode is utilized, the method is not limited by the size and shape of the material, the complex dielectric constant of the irregular material can be accurately tested based on the resonant cavity, the application range of the resonant cavity method is expanded, and the method has important engineering application significance.

A microwave plasma CVD device (1) includes a chamber (10A), a mounting table (110A) provided in a central portion of the chamber (10A) in a plan view of the chamber (10A), a coaxial structural portion (80A) including a central conductor (81) which is located in the central portion of the chamber (10A) in a plan view of the chamber (10A) and is parallel to an axial direction of a symmetric axis in an internal resonance mode of the chamber (10A) and an outer conductor (82) located around the central conductor (81), a plurality of microwave introduction ports (20), (20), . . . that are provided in the coaxial structural portion (80A) of the chamber (10A) and are coupled to match the internal resonance mode of the chamber (10A), and a microwave introduction window (30A) that transmits microwaves while forming a pressure partition wall between the chamber (10A) and a waveguide portion (40A).

The invention relates to an MEMS (micro-electromechanical system) gyroscope array error suppression device and method based on active piezoelectric excitation, and the MEMS gyroscope array error suppression device and method based on active piezoelectric excitation are characterized in that controlled low-frequency micro-amplitude mechanical vibration is applied to an MEMS gyroscope array through a piezoelectric exciter; the internal resonant state of the gyroscope is physically modulated to reduce the temporal correlation of scale factor errors, converting systematic deviations into random noise. In combination with a base matched with a thermal expansion coefficient and bimodal signal processing, the device separates effective signals while suppressing thermal stress interference, so that an array fusion algorithm can eliminate common-mode errors, and the measurement precision is improved to be within 0.5 degree on the premise of not changing the sensor process.

The application relates to a MEMS gyro array error suppression device and method based on active piezoelectric excitation. The MEMS gyro array error suppression device and method based on active piezoelectric excitation designed by the application applies controlled low-frequency micro-amplitude mechanical vibration to the MEMS gyro array through a piezoelectric exciter, physically modulates the internal resonance state of the gyroscope to reduce the time correlation of the scale factor error, and converts systematic deviation into random noise. In combination with a base matched in terms of thermal expansion coefficient and double-mode signal processing, the device can separate effective signals while suppressing thermal stress interference, so that the array fusion algorithm can eliminate common-mode errors, and the measurement precision is improved to within 0.5 degrees without changing the sensor process.

The application discloses a micro magnetic sensor combined with electromagnetic induction and Lorentz force and a preparation method thereof. The sensor comprises a high-frequency resonance component, a low-frequency resonance component and a coupling beam between the two components. The high-frequency resonance component comprises a driving electrode, a high-frequency resonance structure, a first insulating layer on the side of the high-frequency resonance structure, a Lorentz force driving coil, a second insulating layer on the side of the high-frequency resonance structure, a metal shielding layer, a third insulating layer on the side of the high-frequency resonance structure and an electromagnetic induction coil. The low-frequency resonance component comprises an induction electrode, a low-frequency resonance structure, an insulating layer on the side of the low-frequency resonance structure and a metal coil. The application establishes a composite magnetic sensitive architecture of electrostatic driving-electromagnetic induction and Lorentz force driving-electrostatic sensitivity on the internal resonance coupling structure, so as to improve the magnetic sensing performance through the superposition of two types of magnetic sensitive output signals. Meanwhile, the low-frequency resonance amplitude amplification effect of internal resonance is utilized to realize that the low-frequency resonance structure plate capacitor serves as a magnetic sensing signal output, so as to reduce the power consumption of the Lorentz force type magnetic sensitive element.

The present invention discloses a seismic simulation vibration table control method for combined seismic wave and flow loading, comprising the following steps: establishing a seismic simulation vibration table system and a control system; using the target seismic wave and the actual acceleration signal of the vibration table body as feedback signals, and inputting them into the control system; the control system comprises: an anti-disturbance control loop, a PID control loop and an acceleration outer closed loop; the acceleration outer closed loop is used to obtain a corrected actual acceleration signal; the anti-disturbance control loop is used to generate control instructions in six-degree-of-freedom directions; the PID control loop is used to convert the control instructions into control signals for each actuator in the seismic simulation vibration table system through a degree-of-freedom decomposition matrix; the present invention reduces the influence of water dynamics such as waves and flows and their internal resonance on the system accuracy by designing the PID control loop, the anti-disturbance control loop and the acceleration outer closed loop for the seismic simulation vibration table system, thereby achieving accurate tracking of the seismic wave acceleration signal.

The invention relates to the technical field of energy collection, and discloses a multi-directional vibration energy collection type intelligent spacer for a power transmission line, which can automatically collect vibration energy of the power transmission line from multiple directions and improve the energy conversion rate. The power transmission line multidirectional vibration energy collection type intelligent spacer comprises a response module and a power generation module, and the power generation module is installed on the response module. The power generation module comprises a first power generation assembly and a second power generation assembly. The response module comprises a rotating shaft, an internal resonance response assembly and a rotating assembly, the rotating assembly and the internal resonance response assembly are both connected with the rotating shaft, the first power generation assembly is installed on the internal resonance response assembly, and the second power generation assembly is installed on the rotating assembly; the rotating assembly comprises a stator and a rotor; the rotor is fixedly mounted on the rotating shaft; under the action of external force, the internal resonance response assembly swings around the rotating shaft to vibrate the spring mass system, so that the first power generation assembly generates a first electric signal; and the internal resonance response assembly drives the rotor to rotate so as to enable the second power generation assembly to generate a second electric signal.

This invention relates to the field of vibration control technology and discloses a structural coupling vibration isolation system and method for cleanrooms. The system is installed on the floor slab of a building structure and includes an isolation support frame system, a quasi-zero stiffness main support unit, a segmented viscous damper, and a nonlinear tuned mass damping module. The isolation support frame is lowered in the middle to form a suspended foundation pit. The quasi-zero stiffness unit effectively isolates external low-frequency vibrations. The segmented damper achieves low-resistance, high-energy-dissipation limiting for micro-vibrations and large displacements. The equipment base acts as a tuned mass block to adaptively absorb internal resonant energy. This invention, by constructing a coordinated structural coupling vibration control system, can simultaneously achieve ultra-low frequency vibration isolation, wideband adaptive vibration absorption, and seismic safety protection, making it suitable for micro-vibration control scenarios of precision equipment in semiconductor cleanrooms.

The invention discloses a deep and far sea wind wave combined power generation system based on a nonlinear internal resonance principle, and belongs to the technical field of offshore power generation. The system comprises a semi-submersible base, a wind power generation mechanism and a wave energy power generation device. The semi-submersible base comprises three buoys which are annularly and uniformly distributed, and the upper ends and the lower ends of every two adjacent buoys are fixed through a second flexible connecting piece and a third flexible connecting piece which are horizontally arranged respectively; the wind power generation mechanism comprises a tower tube located in the center of the three floating barrels, and an adjustable tuned mass damper is arranged on the tower tube; a wave energy power generation device is arranged between the second flexible connecting piece and the third flexible connecting piece and comprises a wave energy floater; a water cabin is arranged in the wave energy floater; the tower drum vibrates due to wind, energy is transmitted to the wave energy floater, and nonlinear internal resonance is triggered; the wave energy floater converts absorbed energy into electric energy by driving the wave energy conversion device through the heaving plate, and residual kinetic energy is dissipated through the water tank.

This invention discloses a method for identifying internal resonance in flexible structures based on acoustic measurements, comprising: 1. Calculating the natural frequencies and mode shapes of the flexible structure through dynamic modeling and eigenvalue solving to determine that the structure has approximately reducible mode frequencies, satisfying the preconditions for internal resonance; 2. Arranging several sound pressure sensors near the flexible structure to collect the time-domain signal of the dynamic radiated sound pressure of the structure; 3. Using fast Fourier transform to extract the sound pressure amplitude of each sound pressure sensor near a certain low-order natural frequency, and plotting the directivity curve of the sound pressure amplitude with respect to the spatial position of the sensor. By comparing the directivity curve with the geometric characteristics of the mode shapes of the flexible structure, it is determined whether the structure is in an internal resonance state. This invention can identify whether the low-order coupling modes of the flexible structure are excited by monitoring the spatial directivity curve of the radiated sound pressure of the flexible structure, thereby achieving accurate and intuitive identification of internal resonance phenomena in flexible structures through non-contact, simple, and convenient acoustic measurements.

The invention discloses a road vibration broadband low-frequency energy collection device and system based on a nonlinear superstructure, and relates to the technical field of road engineering. The device comprises a bearing packaging shell, a nonlinear superstructure unit array, an energy gathering and frequency up-conversion mechanism, an energy converter, an electric energy management module, a modular interface and a state monitoring unit, through magnetic tuning, pre-tightening tuning or negative stiffness tuning of the nonlinear tuning assembly, the nonlinear superstructure unit forms a bistable situation trap, a multi-stable situation trap or quasi-zero stiffness characteristic, energy is gathered and dispersed in combination with internal resonance coupling, low-frequency wide-spectrum vibration is adapted, and parameter drift can be dealt with; the low-frequency-to-high-frequency conversion is realized by means of an energy gathering and frequency up-conversion mechanism, the electric energy conversion efficiency is improved, a distributed energy supply network is formed in a multi-device array manner by matching with a protective shell and a modular interface, and the power supply requirements of various roadside devices are flexibly met.