16 results about "Wave angle" patented technology

The invention discloses a self-adaptive rotating baseline direction finding method, device and equipment, a medium and a terminal. Signals are continuously collected through the base line rotatable antenna array; rapidly identifying and outputting environment parameters by using the trained environment evaluation model, and evaluating the environment grade; constructing a dynamic direction-finding angle model by combining the attitude parameters and the motion parameters of the mobile platform, the control parameters of the antenna array and the environmental parameters; according to the environment parameters and the environment grades, a dynamic parameter optimization rule is formulated, and control parameters, direction-finding resolving parameters and signal processing algorithm parameters of the antenna array are adjusted; and based on the environmental parameters, the adjusted control parameters of the antenna array, the adjusted direction-finding resolving parameters and the adjusted adaptive filter parameters, calculating an incoming wave angle by using a dynamic direction-finding angle model. According to the method, high-precision incoming wave signal direction finding is realized in a dynamic environment, and the method is suitable for mobile scenes such as unmanned aerial vehicles and vehicle-mounted communication.

The invention discloses an auxiliary direction of arrival estimation and communication method based on a dynamically rotatable space-based intelligent reflecting surface, and belongs to the field of wireless communication. The method specifically comprises the following steps: firstly, a user periodically sends a positioning pilot signal, and the positioning pilot signal is reflected to a base station by an IRS to preliminarily and roughly estimate a direction of arrival from the user to the IRS; then, the IRS is adjusted to turn to the maximum reflection efficiency, and the theoretical rough estimation incoming wave angle of the user is calculated; the IRS direction and the value of a measurement matrix are adjusted according to the rough estimation result, the signal-to-noise ratio of a receiving end is improved, and a more accurate estimation result is obtained; the fine estimation is repeated a plurality of times until the error reaches a specified threshold. After the direction of arrival of the user is estimated, the direction of the IRS is adjusted according to a final estimated angle value so that the reflection efficiency of the system can be maximized, the beam coverage range is reduced to a direction of arrival estimation error threshold value, and the optimal phase shift matrix theta of the IRS is solved by taking the worst signal-to-noise ratio of the maximized beam coverage area as an optimization target. According to the invention, the performance of the intelligent reflecting surface in assisting the wireless communication system is improved.

The invention relates to the field of non-invasive monitoring, and particularly provides a method for evaluating vascular elasticity through radial artery pulse waves. The method comprises the following steps that 1, radial artery pulse waves are obtained; step 2, preprocessing the radial artery pulse wave to obtain an average pulse period; 3, calculating a dominant wave angle based on the average pulse period; step 4, calculating pulse duration based on the average pulse period; step 5, calculating rise time based on the average pulse cycle; step 6, calculating a main wave amplitude based on the average pulse period; step 7, calculating a waveform area based on the average pulse period; and 8, establishing an evaluation model, inputting the dominant wave angle, the pulse duration, the rise time, the dominant wave amplitude and the waveform area into the evaluation model, and outputting a vascular elasticity predicted value by the evaluation model. According to the method, the accuracy of predicting the vascular elasticity is high, and the cost is low.

The invention relates to the technical field of wireless communication signal direction finding, in particular to a broadband high-precision single-channel direction finding device and method based on a time division multiplexing phase shift technology. The device comprises an antenna array used for receiving a 20MHz-1GHz frequency band signal; the antenna signal processing unit is used for carrying out preprocessing before frequency conversion on the received 20MHz-1GHz frequency band signals and intensively transmitting the preprocessed multi-channel signals to the single-channel radio frequency front end; the radio frequency front end is used for down-converting a multi-channel signal to 10.7 MHz and outputting the multi-channel signal through two-stage frequency conversion by adopting a superheterodyne receiver mode; and the direction finding receiver is used for sampling 10.7 MHz signals output by the radio frequency front end by using a 16-bit high-precision ADC (Analog to Digital Converter), performing preset algorithm processing through an FPGA (Field Programmable Gate Array), calculating a wave angle, and outputting received signal spectrum data to the display control computer through a gigabit network port. According to the invention, while the complexity and cost of equipment are reduced, the direction finding precision is improved, the anti-interference capability is enhanced, and the real-time performance is improved.

This invention discloses a frequency domain hydrodynamic analysis method and system. The method includes establishing a detailed geometric model of a floating photovoltaic (PV) system; dividing the waterline according to the arrangement of the PV system; meshing the model to generate a grid system suitable for hydrodynamic analysis; setting analysis parameters based on model data, defining the physical properties of the PV modules, and configuring frequency domain analysis parameters to obtain the PV parameter setting results; using the grid system to perform frequency domain calculations on the PV parameter setting results under different arrangement conditions to obtain key hydrodynamic performance parameters, and analyzing the calculation results to obtain the hydrodynamic performance of the PV system under different wave angles; comparing and analyzing the hydrodynamic performance of the PV system under different wave angles, identifying the optimal and worst performance arrangement schemes, and optimizing the PV arrangement based on the analysis results. This invention effectively analyzes the frequency domain hydrodynamic performance characteristics of floating PV systems under different wave angles.

This invention relates to the fields of underwater acoustic engineering, marine engineering, and sonar technology, and particularly to a passive sound source localization method and system based on a vertical array in a deep-sea environment. The method includes: receiving the time-domain signal radiated by a target sound source using a large-aperture vertical array deployed on the seabed in the deep sea; performing a fast Fourier transform on the time-domain signal to obtain the corresponding signal spectrum; using a spatial power spectrum estimation method to obtain the frequency-domain beam output sound field of the signal spectrum of different array elements at different angles of arrival; calculating template values ​​for the direct wave angle of arrival, the sea surface reflected wave angle of arrival, the direct wave arrival time delay, and the sea surface reflected wave arrival time delay under different assumed sound source distances and depths; combining the four template values ​​with the frequency-domain beam output sound field at different angles of arrival to obtain a passive sound source localization cost function for different sound source distances and depths, thereby achieving the estimation of the target sound source distance and depth.

The invention discloses a WiFi signal direction of arrival estimation method and device based on rotary double antennas. The method comprises the following steps: 1) data acquisition and preprocessing; 2) constructing a virtual antenna array; 3) introducing a rotation relation to simplify a correlation model: further simplifying the correlation model in combination with spatial characteristics of a rotation antenna of a rotation device, and finally converting the correlation model into a linear equation to solve a direction of arrival; 4) removing an angle of arrival result influenced by multiple paths; and 5) device application: deploying the device in an actual indoor positioning scene for application. According to the method provided by the invention, the virtual circular antenna array is simulated by rotating the double antennas, so that the double physical antennas have the three-dimensional angle measurement capability, the rotation characteristics of the double antennas are introduced into the correlation model, the direction of arrival calculation is successfully converted into a linear equation set for rapid solution, and compared with a traditional direction of arrival estimation method, the method provided by the invention has the advantages that the calculation efficiency is greatly improved. According to the method, a higher direction-of-arrival resolving speed is obtained with similar angle measurement precision, and experiments show that the resolving speed of the method is increased by 10-20 times, so that the problems that an existing double-antenna angle measurement device cannot automatically estimate the three-dimensional direction of arrival and time consumption is large are solved.

The invention discloses a satellite-borne laser water depth correction and extraction method considering sea surface waves, and the method comprises the following steps: carrying out the sea surface wave fitting of satellite-borne laser sea surface photon points through employing a smooth spline function, and obtaining the instantaneous wave slope and elevation value of each sea surface photon position; modeling the incident line of each photon point according to the fitting result, and matching the seabed photon points with the sea surface photon points based on the modeling line of the incident light to calculate an initial water depth value; carrying out refraction correction on the initial water depth value according to a wave angle and a photon incidence angle of a sea surface wave fitting result of a corresponding position in combination with marine environment characteristics; and performing geophysical correction on a result after refraction correction to obtain a water depth extraction result based on the average sea level. Through water depth correction considering the sea surface wave angle and the wave height, sounding errors caused by sea surface waves are effectively compensated, and the satellite-borne laser water depth extraction precision and reliability are remarkably improved.

The invention belongs to the technical field of underwater acoustic signal processing, and particularly relates to a multi-array-element ranging data fusion method, which comprises the following steps of: 1, for a one-dimensional uniform linear array with N array elements, selecting an array element 1 as a reference to establish a coordinate system, selecting the array element 1 to switch to a transmitting state, and transmitting a sine single-frequency signal with a transmitting frequency f0; 2, switching all array elements to a receiving state, recording waveform data a of each transducer, performing Fourier transform on data of each channel, expanding the data into superposition of single-frequency signals by using Fourier transform, and adding different phase shifts to different single-frequency signals; according to the method, the steps of signal emission, receiving processing, data fusion and the like are sequentially carried out through multiple array elements, the incoming wave angle and path are accurately calculated, and the distance measurement precision is improved; based on mature equipment and common technologies, engineering realization is easy; and the anti-noise capability is enhanced through multi-array-element data processing.

The invention discloses a method for solving zero-order aerodynamic parameters after oblique detonation waves based on a gradient descent algorithm, and belongs to the technical field of aerodynamics. According to the method, an iterative objective function is constructed on the basis of a control equation of a single-step chemical reaction, and a derivative of the objective function is solved. And solving to obtain a post-wave mass fraction and other aerodynamic parameters through a Newton iteration method. Compared with two different examples, the method provided by the invention is accurate and effective, and has a remarkable advantage in calculation speed. Furthermore, the method can also be used as an analysis means to research the mutual influence relationship among all parameters in detonation. In addition to forward solving, the method can also be developed into a reverse design means, and a corresponding wall angle is solved under the condition that a wave angle is given. Therefore, the method can be used as a quick and effective calculation and analysis tool under the condition that detonation gas composition is not concerned and detonation post-wave aerodynamic parameters are more concerned, and has a wide application prospect.

The invention discloses a millimeter wave angle extraction and laser link aiming method based on layered channel estimation, and relates to the field of laser communication. The objective of the invention is to solve the problem of low laser aiming accuracy and efficiency caused by low millimeter wave angle extraction efficiency and accuracy in the existing radio frequency assisted laser communication method. The method comprises the following steps: acquiring an equivalent received signal model of a carrier; constructing a channel model and a beam domain dictionary, and applying the beam domain dictionary to the channel model to obtain a vectorized channel model applying the beam domain dictionary; vectorizing the equivalent received signal model of the carrier to obtain a vectorized observation signal model; obtaining a candidate angle domain by adopting an M-layer codebook step-by-step scanning strategy, and obtaining a beam emission angle estimated value and a beam arrival angle estimated value based on the candidate angle domain; and according to the measurement precision of the beam emission angle estimation value and the beam arrival angle estimation value, obtaining the laser link pointing uncertainty area. The method is used for laser angle estimation and link aiming.

The present application relates to the technical field of millimeter wave radar, in particular to a kind of automatic calibration method of installation angle;It is suitable for the installation angle of vehicle-mounted millimeter wave angle radar is automatically calibrated;Collect the radar data of vehicle-mounted millimeter wave angle radar, obtain the standard point cloud data of each frame radar data and store in point cloud data group;When the standard point cloud data stored in the point cloud data group reaches the preset frame number, the installation angle error of the vehicle-mounted millimeter wave angle radar is obtained by processing the point cloud data group;According to the installation angle error obtained by processing multiple times, the installation angle error wave gate is obtained, and the installation angle of the vehicle-mounted millimeter wave angle radar is automatically calibrated according to the installation angle error wave gate;Advantages: real-time calibration during vehicle driving process;Angle error range can be dynamically adjusted, so that the calibration value converges;It can be judged that the position of radar may have been shifted, and large-scale shift caused by collision and jolt can be calibrated.

A vital sign detection method based on spatio-temporal equivalent virtual array technology. According to the phase information demodulated from the received single-channel continuous wave radar signal, an equivalent multi-channel virtual array signal is obtained through signal recombination. Then, the subspace method is used to perform frequency domain estimation on the multi-channel virtual array signal to obtain the incoming wave angle information. According to the target frequency converted from the incoming wave angle information, the vital sign information of the target is accurately obtained through a coarse-to-fine frequency estimation method. The present invention utilizes the similarity between the single-channel phase signal of a CW radar with single input and single output (SISO) and the multi-channel array signal of a radar with single input and multiple outputs (SIMO) to synthesize an equivalent virtual array, complete the transformation from time to space, and thus achieve accurate and stable estimation of the breathing frequency and heart rate of the human body with super resolution.

The invention discloses a method for calculating a space time delay compensation value of an antenna array, and the method comprises the steps: obtaining a coordinate of a virtual far-field target according to a far-field condition satisfied by a real space target, and an azimuth angle and a pitch angle of the real space target; according to the coordinate information of each antenna in the antenna array and the coordinate information of the virtual far-field target, obtaining an equivalent wave path difference of each antenna in the antenna array to the real space target; and according to the equivalent wave path difference of each antenna in the antenna array for the real space target, obtaining a space time delay compensation value required by signal synthesis of each antenna in the antenna array. The method does not need to calculate the incoming wave angle of each antenna in the antenna array to the space target, and can calculate the signal space time delay compensation value when the antenna array carries out array signal synthesis under the condition that the precise distance between the space target and the antenna is not needed.

The application relates to the technical field of wireless communication signal direction finding, in particular to a wide-band high-precision single-channel direction finding device and method based on time division multiplexing phase shift technology. The device comprises an antenna array for receiving 20MHz-1GHz frequency band signals; an antenna signal processing unit for pre-processing the received 20MHz-1GHz frequency band signals before frequency conversion and centrally transmitting the pre-processed multi-channel signals to a single-channel radio frequency front end; the radio frequency front end is used in the mode of a superheterodyne receiver, and through two-stage frequency conversion, the multi-channel signals are down-converted to 10.7MHz output; a direction finding receiver is used for sampling the 10.7MHz signals output by the radio frequency front end by using a 16-bit high-precision ADC, performing preset algorithm processing through an FPGA, and outputting the calculated wave angle to a display control computer through a gigabit network port together with the received signal spectrum data. The application can reduce the complexity and cost of the equipment, improve the direction finding precision, enhance the anti-interference ability and improve the real-time performance.

The utility model relates to an array horn antenna transmit-receive system based on a 77GHz millimeter wave radar, and belongs to the technical field of antennas. The antenna comprises a transmitting antenna and three receiving antennas which are waveguide-coupled horn array antennas, each horn array antenna comprises a three-layer structure, the bottom layer is a first feed structure layer of a bent waveguide structure, and the middle layer is a second feed structure layer of an array slot structure; and the upper layer is a horn antenna layer with a horn array structure. The horn antenna is composed of M array elements, and the M array elements are symmetrically distributed about the center feed position. Therefore, the array horn antenna system based on the 77GHz millimeter wave radar is provided, and the array horn antenna system has the advantages that waveguide feeding is achieved, wide wave beams can be guaranteed, mutual coupling between the antennas is small, the consistency between the antennas is good, the loss is small, and the gain is high. The array horn antenna system can be applied to a vehicle-mounted millimeter wave angle radar, and middle and long distance target detection is realized.