24 results about "Angle modulation" patented technology

The invention relates to a multi-fan blade angle non-uniform distribution structure for reducing beat vibration noise, and aims to solve the technical problem that the beat vibration noise is difficult to reduce through scientific and accurate blade number setting and blade angle non-uniform distribution design of existing similar products. Blades at a fan of the structure are arranged at non-uniform angles by taking a shaft core in a hub as a center, and the non-uniform angles are circular angles formed by the blades which are arranged at non-uniform angles by taking the shaft core in the hub as the center; the method is characterized in that the blades modulate the real-time rotating speed of each fan through a control center so as to avoid frequency discretization or set the number of the blades according to discrete noise frequency distance, and finally the non-uniform distribution angles between the blades are obtained through blade angle non-uniform distribution modulation; the control center is a control module which comprises a control chip and a signal conversion input and output port and is used for data calculation and processing. When the mode B is selected in the real-time regulation and control stage of the blade angle non-uniform distribution modulation, a sorting and interval greedy algorithm is adopted.

An optical angle modulator includes: a first unit configured to generate first angle-modulated light and second angle-modulated light by performing angle modulation on continuous light using an electrical signal; and a second unit configured to generate third angle-modulated light by causing partially degenerate four-wave mixing of the first and second angle-modulated lights. A frequency band of the first angle-modulated light and a frequency band of the second angle-modulated light are different, and an angle of the second angle-modulated light decreases due to the electrical signal while an angle of the first angle-modulated light is increasing due to the electrical signal, and the angle of the second angle-modulated light increases due to the electrical signal while the angle of the first angle-modulated light is decreasing due to the electrical signal.

The application provides a kind of quick detection method of wave-absorbing coating defect based on incident angle modulation, belongs to the field of defect detection, comprising: initializing detection system;Multi-angle incident sweep frequency test is carried out on the surface of defect-free coating;Set the incident mode to grazing incidence, sweep frequency test is carried out on the surface of defective coating, and whether there is surface defect is determined by comparison and analysis with reference data;Set the incident mode to normal incidence, sweep frequency test is carried out on the surface of defective coating, and whether there is circular defect is determined;When it is determined that circular defect exists, multi-angle sweep frequency inversion is executed to quantify defect size, and actual physical size is obtained by using elliptical correction model correction;An adaptive calibration module based on deep learning is introduced to obtain the final defect size.The application can meet the needs of stealth aircraft and other aerospace equipment.

The application provides a liquid tank strong dynamic load pressure field reconstruction and global safety evaluation method, comprising the following steps: S100, establishing a three-dimensional coordinate system of the liquid tank, obtaining actual impact point coordinates and field point position coordinates, and calculating the Euclidean distance of wave front propagation and the deflection angle relative to the ballistic axis; S200, constructing a pressure field model containing anisotropic angle modulation terms and distance attenuation terms, and introducing a fluid-solid coupling phase shift parameter in the anisotropic angle modulation terms; S300, determining the optimal eigenvalue of the fluid-solid coupling phase shift parameter by minimizing the prediction error through an optimization algorithm, so as to represent the wave front lag or distortion effect of the shock wave when propagating in the limited liquid medium; S400, generating a normalization factor based on the nonlinear transfer function solved out of the optimal eigenvalue η , performing cleaning of experimental data; or directly calculating the impact pressure estimation value at the weak point based on the perceived impact point and the preset virtual point coordinates to perform structure safety evaluation.

The invention discloses a matrix optical switch and optical communication equipment, and relates to the technical field of optical communication. The matrix optical switch separates input light into two beams of light with the same polarization state through the first polarization separation conversion unit; the two beams of light are spatially combined through the first lens group and then jointly enter the same pixel area of the first silicon-based liquid crystal, and first-time angle modulation is completed; combining the two beams of light subjected to the first-time angle modulation again to the same pixel area of the second silicon-based liquid crystal through the polarization multiplexing unit to complete second-time angle modulation; and the two beams of light after the second angle modulation are transmitted to the second polarization separation conversion unit through the second lens group, orthogonal polarization is recovered, and the beams are combined and output. The two beams of light in the same polarization state are sequentially converged to the same pixel area corresponding to the two pieces of silicon-based liquid crystal, so that the pixel utilization rate and the number of available ports are increased.

The present invention provides a control method and device for a test equipment based on an LCC resonant converter. The method includes: calculating the error quantity of a two-module LCC resonant converter, and obtaining a first modulation signal and a second modulation signal through dual-carrier hybrid control; acquiring the adjustment quantities of the first-module LCC resonant converter and the second-module LCC resonant converter; obtaining the conduction angle modulation signals of the first-module LCC resonant converter and the second-module LCC resonant converter; and obtaining a third modulation signal and a fourth modulation signal through interleaved control, so as to realize the control of the switching tubes of the two modules. By implementing the embodiments of the present application, the first modulation signal and the second modulation signal are obtained through dual-carrier hybrid control to equalize the voltage between the module LCC resonant converters, and then the output voltage ripple is reduced through output interleaved control, so that the converter can achieve zero-voltage soft switching of the switching tubes under a wide range of operating conditions and reduce the variation range of the switching frequency.

The invention discloses an ultra-sensitive angle modulation detection method based on a transverse electric mode surface lattice resonance metasurface, and belongs to the technical field of surface plasmon photonics. The all-metal metasurface is adopted, traditional optical elements such as prisms are avoided, traditional laser is replaced with broadband light, limitation of monochromatic laser can be broken through, small-angle incidence is guaranteed, in addition, the influence of the liquid level refraction phenomenon is considered, and ultra-sensitive angle modulation detection is achieved according to the SLR principle. The angle modulation sensitivity obtained through actual measurement is improved by one order of magnitude compared with an existing advanced result, and the highest angle modulation sensitivity can reach 4304.35 degrees / RIU.

The invention provides a multi-harmonic peak modulation method based on an arbitrary phase angle PSS, and the method comprises the steps: 1, constructing an arbitrary angle phase modulation model; 2, analyzing a PSS modulation signal at any angle; 3, carrying out radar echo modulation analysis; and 4, performing matched filtering analysis. According to the invention, the practical application capability of the PSS in electronic countermeasure is expanded; according to the invention, a non-ideal PSS modulation model is established, and theoretical derivation and simulation analysis are carried out on the modulation signal at any regulation angle to obtain the influence of different modulation parameters on the frequency spectrum of the modulation signal. According to the method, the influence of parameters such as regulation and control angles on the radar echo signal frequency spectrum and matched filtering output is analyzed, and the mapping relation between the modulation parameters and the interference effect is established.

An optical angle modulator includes a first generation unit that generates first angle-modulated light and second angle-modulated light by angle-modulating continuous light with an electrical signal, and a second generation unit that generates third angle-modulated light by partial degenerate four-wave mixing of the first angle-modulated light and the second angle-modulated light, the frequency band of the first angle-modulated light and the frequency band of the second angle-modulated light being different, the angle of the second angle-modulated light decreasing due to the electrical signal during a period in which the angle of the first angle-modulated light increases due to the electrical signal, and the angle of the second angle-modulated light increasing due to the electrical signal during a period in which the angle of the first angle-modulated light decreases due to the electrical signal.

The invention relates to the technical field of aero-engines, and discloses a turbine pneumatic excitation suppression method and device based on guide vane inclination angle modulation. According to the design result of the turbine guide vane, pneumatic excitation is restrained by adjusting the inclination angle of the turbine guide vane; and analyzing a turbine guide vane inclination angle suppression pneumatic excitation result in a spectral analysis mode. By organically modulating the circumferential distribution of the inclination angle of the guide vane, the excitation energy peak value at the dominant frequency is efficiently reduced by using the phase difference and the radial pressure distribution difference between disturbances at different heights of the outlet of the guide vane caused by the inclination angle change, and meanwhile, no additional high-strength disturbance is introduced, so that the aerodynamic performance of the turbine cannot be obviously influenced; and collaborative optimization of aerodynamic performance and excitation suppression is realized. Therefore, the method finally aims at the suppression mode of pneumatic excitation, the limitation in practical application is broken through, and the suppression effect and efficiency of the pneumatic excitation of the turbine are improved.

The invention discloses an optical diffusion plate and a sound atmosphere lamp. The optical diffusion plate includes: a base material; the base material comprises a light incident surface opposite to the light emitting unit and a light emergent surface opposite to the light incident surface; a scattering layer is arranged in the base material, and the base material is filled with the scattering layer; the scattering layer comprises at least one kind of scattering particles, and the scattering particles are non-uniformly distributed at different preset positions in the scattering layer at different preset weight densities based on a weight density distribution function; wherein the weight density distribution function represents the influence of the preset position of the optical diffusion plate, the radial distribution contribution, the angle modulation contribution and the thickness distribution contribution on the reference weight density of the scattering particles. According to the embodiment of the invention, the hot spot phenomenon existing in the light-emitting unit can be effectively inhibited, the light-emitting uniformity is improved, and relatively high light-emitting efficiency can be ensured.

Provided is a display device including a backlight module, a half wave plate, a viewing angle modulation layer, and a display panel stacked in sequence. The display panel includes a first polarizer, a pixel layer, and a second polarizer stacked in sequence. The first polarizer is disposed between the viewing angle modulation layer and the pixel layer. The backlight module includes a prism sheet, and the prism sheet includes a plurality of prism structures arranged along a first direction. The half wave plate has a slow axis, and the slow axis is parallel to a second direction. The first direction is not parallel to, and not perpendicular to, the second direction.

The invention relates to the technical field of optical ranging, and discloses an indirect flight time acquisition method and device, equipment, a storage medium and a product, and the method comprises the steps: configuring a polarization laser pulse light source for each indirect flight time camera, and determining the distribution state of each indirect flight time camera after configuration; performing multi-stage polarization multiplexing and dynamic polarization modulation on the polarization angle of each indirect time-of-flight camera according to the distribution state to obtain a polarization state and an angle modulation strategy; controlling the indirect time-of-flight camera to generate laser pulses with different polarization angles based on a polarization state and an angle modulation strategy; and receiving the reflected light intensity of the laser pulse reflected by the target scene, and determining the indirect flight time of the target scene based on the reflected light intensity. A laser light source with an independent polarization angle is distributed for each camera by utilizing dynamic polarization modulation, so that laser signals between the cameras are prevented from mutual interference in the polarization direction, and the expansibility of the number of the cameras and the detection precision of the cameras are greatly improved.

The invention discloses a photon terahertz signal modulation and demodulation method, and relates to the technical field of terahertz communication and radio over fiber communication. Conjugate angle modulation is realized at a transmitting end through a dual-wavelength generator and an optical phase modulator, a target signal is converted into an angle modulation optical signal with a constant envelope characteristic, and preliminary spectrum spreading is realized. And the two paths of conjugate angle modulation optical signals pass through a photoelectric detector to realize further expansion of the signal frequency spectrum and generate broadband terahertz signals. And a receiving end completes signal demodulation through an improved angle demodulation module and recovers a target signal. Compared with the prior art, higher angle modulation depth is supported, the generated terahertz signal is low in phase noise and flexible and adjustable in carrier frequency, and more efficient angle modulation and more stable angle demodulation processing in a photon terahertz transmission system can be realized, so that the signal-to-noise ratio of the terahertz signal is improved, and the signal-to-noise ratio of the terahertz signal is improved. The method is used for assisting long-distance and high-fidelity transmission and the like.

The invention discloses a synchronous equivalent multi-wavelength microscopic interference measuring method based on incident angle modulation, and belongs to the technical field of measuring instruments. According to the method, under the condition of a single-wavelength light source, multiple groups of interference wavelengths are equivalently constructed by modulating an illumination incident angle, so that the interference measurement range is expanded, and the phase reconstruction precision is improved. According to the system, a blazed phase grating is loaded by using a spatial light modulator, a plurality of illumination light beams with different incident angles are synchronously generated by regulating and controlling different diffraction orders, so that interference signals corresponding to equivalent wavelengths are formed on the surface of a sample, and interference information of each channel is synchronously acquired through polarization regulation and control. The system does not need multiple light sources or a wide-spectrum light source, is simple in structure, is good in measurement synchronism, is large in measurement range, is high in stability, and is high in anti-interference capability.

The present invention discloses a method, device and system for generating a drive signal for sensor testing equipment. The method comprises the following steps: performing improved dual-carrier hybrid control on the total regulation voltage of the sensor testing equipment to obtain a carrier peak modulation signal and a conduction angle modulation signal; obtaining a first regulation amount and a second regulation amount based on a first output voltage of an LCC resonant converter of a first module and a second output voltage of an LCC resonant converter of a second module; superimposing the first regulation amount and the second regulation amount on the conduction angle modulation signal respectively to obtain a first module conduction angle modulation signal and a second module conduction angle modulation signal; performing dual-loop control processing on the carrier peak modulation signal and the first module conduction angle modulation signal to obtain a first modulation signal and a second modulation signal; and combining the first modulation signal, the second modulation signal, the carrier peak modulation signal and the second module conduction angle to obtain drive signals for all switching tubes. The present invention can reduce output voltage ripple and reduce the volume of filter capacitors.

The application provides a single firewire communication method based on current detection and thyristor modulation, comprising: calibrating zero-crossing timing reference and reference current; establishing mapping of data symbols and thyristor conduction angle and dynamically adjusting according to loop current size, encoding to-be-transmitted data to generate encoding sequence; converting the encoding sequence into a thyristor trigger signal to drive the conduction angle to conduct at the corresponding moment, generating stable current fluctuation through conduction angle modulation and transmitting to the receiving end; the receiving end collects loop current fluctuation signals in real time and processes them through multi-stage filtering to obtain effective current signals, initializes decoding threshold according to the reference current, identifies the conduction angle change corresponding to the effective current signals to restore the symbols, and outputs after checking the symbols. The thyristor specific conduction angle is used for data encoding, the small change of the detected loop current is used for data decoding, and the problems of unstable communication and high decoding error rate in the single firewire small current scene are solved.

The invention relates to a bottle-shaped beam generation system and method based on emission angle modulation, and relates to the technical field of structured light generation, and the bottle-shaped beam generation system based on emission angle modulation comprises a light source which is used for outputting incident light; the spatial light modulator is written with complex amplitude distribution information after Fourier transformation of the central annular light field of the bottle-shaped light beam, and is used for modulating incident light to obtain a structured light field; and the lens is used for performing Fourier transform on the structured light field and generating a bottle-shaped light beam at a focal plane of the lens. According to the invention, the emission angle of the non-circular bottle-shaped light beam can be regulated and controlled, so that the non-circular bottle-shaped light beam can be reconverged at a single point in the propagation process, thereby remarkably reducing the aperture required by a receiving end, and improving the miniaturization and integration capabilities of the system.

The invention provides a driving method and system for a spiral vector thruster, relates to the technical field of aircraft control, and is applied to the spiral vector thruster comprising a driving source, a flexible resonant shaft and a rotor wing. In the method, based on a target thrust direction for the spiral vector thruster, a modulation angle for a lateral deviation working angle of the flexible resonant shaft is determined. And based on the modulation angle of the lateral deviation working angle of the flexible resonance shaft and a preset maximum rotation angle corresponding to the driving source, determining a modulation angle of a target lead lag angle of the flexible resonance shaft. And the angle of the target lead lag angle of the flexible resonance shaft is modulated into the modulation angle of the target lead lag angle of the flexible resonance shaft, so that the angle of the lateral deviation working angle of the flexible resonance shaft is modulated into the modulation angle of the lateral deviation working angle of the flexible resonance shaft, and therefore precise control over the thrust direction of the spiral vector thruster can be achieved.

A radio frequency (RF) transceiver includes a reference signal source to generate a reference signal, a local RF source to generate a local RF signal, and a mixed signal phase / frequency detector to compare the reference signal to the local RF signal and generate a difference signal from the comparison, wherein the difference signal includes a modulation component and an error component. The transceiver further includes a receiver front end to receive an angle modulated RF signal and downconvert the angle modulated RF signal to a baseband signal, and a quadrature modulator configured to angle modulate the reference signal source with the baseband signal.

The invention provides a method for rapidly detecting defects of a wave-absorbing coating based on incident angle modulation, and belongs to the field of defect detection.The method comprises the steps that a detection system is initialized; carrying out multi-angle incidence frequency sweeping test on the surface of the defect-free coating; setting an incidence mode as grazing incidence, performing a sweep frequency test on the surface of the defective coating, and comparing and analyzing with reference data to judge whether surface defects exist or not; setting an incidence mode as a vertical incidence mode, carrying out a sweep frequency test on the surface of the defective coating, and judging whether a circular defect exists or not; when the existence of the circular defect is determined, executing multi-angle sweep frequency inversion to quantify the defect size, and correcting by using an ellipse correction model to obtain an actual physical size; and introducing a self-adaptive calibration module based on deep learning to obtain a final defect size. According to the invention, the requirements of invisible airplanes and other aerospace equipment can be met.

The invention discloses a polarizing film switching device capable of finely adjusting an angle, and solves the problem that an existing angle modulation method can only realize imaging of a plurality of specific polarization angles or is tedious in operation. The device specifically comprises a support with a light through hole, a rotating shaft vertically arranged on the side wall of the support, a target wheel rotatably sleeving the rotating shaft, four polarization assemblies and a normal lens which are distributed on the target wheel in the circumferential direction and are the same in size, and a first driving assembly and a second driving assembly which are arranged on the support. The end face of the target wheel is parallel to the side wall of the support, and a gap is formed between the target wheel and the support. The acting end of the first driving assembly is connected with the four polarization assemblies and used for driving the four polarization assemblies to rotate at the same time. The acting end of the second driving assembly is connected with the target wheel and used for driving the target wheel to rotate so as to switch any polarization assembly or normal lens to correspond to the light passing hole.

The present application provides a dynamic navigation and positioning method and system for intelligent fully mechanized coal mining, which relates to the technical field of shearer navigation and positioning. The method includes: calculating the root mean square value of the three-axis vibration acceleration signal of the target shearer; when the root mean square value is greater than or equal to a preset threshold, increasing the modulation frequency of the rotary modulation platform and simultaneously reducing the modulation angle range to a preset angle range for reciprocating motion; conversely, reducing the modulation frequency of the rotary modulation platform and restoring the modulation angle range to 360° for periodic rotational motion; correcting and compensating the output data of the gyroscope to obtain attitude data; and performing weighted fusion on the attitude data and the odometer data to obtain the navigation and positioning result. By implementing this method, the motion parameters of the rotary modulation platform can be dynamically adjusted, increasing the modulation frequency and reducing the angle range under strong vibration, and reducing the frequency for full-angle compensation under weak vibration, effectively addressing the problem of poor real-time compensation of traditional fixed-frequency full-angle modulation under strong vibration conditions.

The utility model provides a code scanner with a stepless angle modulation hovering function, which comprises a head assembly, a base, a pressing plate, a rotating shaft and a gasket, a first cavity with a semicircular section is arranged in the base, the pressing plate is arranged in the base, a second cavity with a semicircular section is arranged on the pressing plate, and the rotating shaft is arranged in the second cavity. The first cavity and the second cavity are matched to form a mounting cavity with a circular section, and the rotating shaft is arranged in the mounting cavity; and the gasket is arranged on the inner wall of the second cavity and is in damping fit with the rotating shaft. An adjusting hole is formed in the top side of the base and communicates with the first cavity. A connecting support is arranged at the bottom of the head assembly, penetrates through the adjusting hole and is connected with the rotating shaft. The code scanner is simple in structure and convenient to manufacture, an adjustable stepless hovering structure is formed through damping cooperation of the gasket and the rotating shaft, the head assembly can stably stay at any angle within an allowable range, the fixed angle limitation of a traditional code scanner is broken through through the design, and the multi-scene flexible adjustment requirement can be met.