17results about How to "Achieve estimates" patented technology

The present application relates to the field of active sonar target detection, and relates to a kind of adaptive target detection method and system suitable for reverberation edge environment.The method of the present application comprises: selecting the data of unit to be detected as main data, and selecting the received data of multiple distance units on both sides of the unit to be detected as overall auxiliary data;Overall auxiliary data is distributed in the three uniform reverberation areas formed by the left reverberation edge and the right reverberation edge of the unit to be detected, and is divided into three auxiliary data subsets accordingly;Modeling target adaptive detection as a binary hypothesis testing problem including no-target hypothesis and target hypothesis;Obtain the joint probability density function of main data and overall auxiliary data under no-target hypothesis and target hypothesis;Based on the modified two-step generalized likelihood ratio test criterion, the joint probability density function and the probability density function of main data and auxiliary data subsets are processed in turn, and the final detection expression is obtained to realize target adaptive detection.

The application discloses a kind of even circle array one-dimensional spatial spectrum direction finding signal processing device, including data processing and covariance matrix module, MUSIC algorithm processing module, Capon algorithm processing module, processing result fusion module and DML algorithm processing module;The function of data processing and covariance matrix module is received signal pre-processing, and covariance matrix is obtained by calculation;MUSIC algorithm processing module is calculated using input covariance matrix to obtain the MUSIC spatial spectrum of receiving array;Capon algorithm processing module is calculated from covariance matrix to obtain the Capon spatial spectrum of receiving array;Processing result fusion module analyzes and judges the calculation result of MUSIC spatial spectrum and Capon spatial spectrum, whether MUSIC spatial spectrum needs iterative search, obtains the direction finding result of incoherent signal, and judges whether it contains coherent signal;DML algorithm processing module processes a pair of coherent signal DOA calculation, and outputs spatial signal direction finding result.This device can accurately calculate the DOA of incoherent signal;And on the basis of incoherent signal direction finding, a pair of coherent signal direction finding is completed.

This invention discloses a soft-constraint target tracking method and system based on genetic resampling, belonging to the field of target tracking technology. The method includes: constructing a target tracking model based on the target being tracked; generating multiple particles required for particle filtering based on the initial state value of the target being tracked; updating each particle over time based on the target tracking model to predict the state and weight of each particle; resampling each particle using a genetic algorithm; calculating the corrected likelihood function of the resampled particles based on the measurement equation; correcting the predicted weights based on the corrected likelihood function; and updating the predicted state based on the corrected weights to obtain the final estimated state of the target being tracked. This invention can integrate known nonlinear inequality soft constraints in the tracking of ground moving targets, improving the tracking accuracy of ground targets under such soft constraints.

The invention discloses an event-assisted unmanned aerial vehicle night precise landing system and method. The system comprises a high-frequency dynamic infrared sign array module, an event camera module, a pose resolving module and a landing control module. The system takes a high-frequency dynamic infrared mark array as a positioning reference, an event camera carried on the unmanned aerial vehicle captures an optical event flow with unique time sequence characteristics by accurately controlling the independent flicker frequency of each infrared light source, then the pose of the unmanned aerial vehicle is calculated by using an N-point perspective method, and finally accurate landing is realized by a landing control module. According to the invention, the event camera and the high-frequency dynamic infrared sign array are innovatively combined, the cooperative working mechanism of the event camera and the high-frequency dynamic infrared sign array is utilized, sub-millisecond-level positioning feedback is realized in a complex environment, the limitation of a traditional static optical sign is broken through, the positioning precision and reliability are improved, and the method is suitable for accurate take-off, landing and positioning of the unmanned aerial vehicle at night and in the complex environment.

The invention relates to the technical field of motor control, and particularly discloses a high-precision rotating speed prediction control system and method for a permanent magnet synchronous motor, and the system comprises a rotating speed control module which is used for converting a given rotating speed signal of the permanent magnet synchronous motor into a q-axis component of a stator current given signal, the rotating speed control module is internally provided with a linear super-spiral sliding-mode observer which is used for realizing real-time observation of various torque disturbances and is based on a linear improved super-spiral algorithm; the current control module is used for receiving a three-phase current signal of the permanent magnet synchronous motor and a stator current given signal in the rotating speed control module, outputting a voltage given signal, and generating a PWM signal after SVPWM modulation; and the inverter receives the PWM signal and converts the DC voltage of the power circuit into a voltage signal for actually controlling the operation of the permanent magnet synchronous motor, so as to solve the problem of rotating speed fluctuation caused by load disturbance of the traditional permanent magnet synchronous motor.

The application discloses a fracturing well perforation cluster flow inversion method and system based on distributed optical fiber acoustic vibration, and comprises the following steps: a response calibration model between unit flow rate and an acoustic energy index is established; a distributed optical fiber acoustic vibration system is arranged in a fracturing well wellbore; acoustic vibration signals are acquired and processed; the acoustic energy index is input into the calibration model to calculate volumetric flow; and a perforation cluster flow distribution map is output. According to the method, inversion processing and result output of volumetric flow of multiple perforation clusters in the fracturing well wellbore can be realized, estimation of the volumetric flow of the multiple perforation clusters in the fracturing well wellbore is realized, and technical support is provided for production monitoring, productivity diagnosis and fine regulation and control in the field of oil and gas reservoir development.

The present disclosure provides a control entity for a wireless communication system, the wireless communication system comprising a receiving entity, a transmitting entity, and a digital controllable scatterer (DCS), the DCS comprising a plurality of controllable scattering units. The control entity is configured to: determine a maximum number of training intervals; estimating a direct channel between the transmitting entity and the receiving entity; determining, for each training interval, a configuration set comprising one or more index subsets, each index subset comprising one or more indexes, each index corresponding to one of the plurality of scatter units included in the respective unit subset; an iterative process is performed to determine, for each training interval, an updated phase configuration for a plurality of scattering units of the DCS.

The application discloses a kind of underwater vehicle propeller shaft frequency and blade frequency variational holographic spectrum identification method and device, variational holographic spectrum method utilizes the thought of holographic representation, realizes the robust high-dimensional holographic representation of nonlinear non-stationary signal, obtains variational holographic spectrum diagram, by feature extraction to variational holographic spectrum diagram, realize the identification and estimation of underwater vehicle propeller shaft frequency, blade frequency and blade number;The method introduces variational mode decomposition, effectively solves the mode aliasing problem of EMD in holographic hilbert spectrum analysis method;According to the characteristics that propeller modulation signal in underwater vehicle radiation noise is low frequency slow change, segmented fourier transform is introduced, the problem that there is large error when hilbert spectrum analysis method is processed low frequency slow change signal is solved.The method solves the problem of insufficient representation when the commonly used radiation noise analysis method LOFAR analysis, DEMON analysis and various improved algorithms are analyzed in nonlinear non-stationary signal.

This invention discloses a controller orientation localization method and system based on the main lobe direction of beamforming, comprising: acquiring and receiving intermediate frequency or baseband signals from a UAV terminal to obtain timestamped IQ data, and dividing it into multiple time slices according to a preset duration; determining a corresponding angle label for each time slice to form an angle-data segment mapping relationship, wherein the angle label is generated by UAV motion scanning; performing spectral or time-frequency analysis on the IQ data of each time slice to determine the target frequency band where the target signal is located; extracting and normalizing intensity indicators; constructing radiation pattern data; performing radiation pattern smoothing and main lobe sector determination; and performing orientation output and confidence calculation. This invention does not require strict array calibration and multi-channel angle measurement, and can achieve controller orientation estimation under single-channel or few-channel UAV reception conditions. This invention does not rely on communication protocol demodulation, and can construct the radiation pattern based on the energy characteristics of the target frequency band, making it applicable to different standards and encryption conditions.

This invention provides a method and apparatus for identifying errors in a multi-beacon long baseline positioning system. The method includes the following steps: acquiring an initial long baseline underwater positioning model; establishing a multi-beacon underwater positioning model based on the long baseline underwater positioning model and the geometric relationship between the underwater target center and the beacons; obtaining a system error identification model based on the multi-beacon underwater positioning model; calculating the time delay residual using the system error identification model and the underwater target positioning process; constructing an optimal test statistic D for the system error identification model by analyzing the time delay residual; obtaining a selection criterion for the system error identification model based on the optimal test statistic D; and selecting the optimal system error identification model based on the selection criterion. The system error identification model and optimal model selection criterion proposed in this invention can provide theoretical and technical support for high-precision measurement and navigation positioning of underwater targets.

The invention provides a target region tissue thermal treatment temperature distribution control method and system based on ultrasonic temperature measurement. The method comprises the following steps: acquiring an ultrasonic image sequence of a target region tissue under the condition that the target region tissue is preheated at a first temperature; calculating ultrasonic thermal strain according to the ultrasonic image sequence to obtain a temperature image of the target region tissue at the first temperature; according to the temperature image, the physical property parameters and the biological heat transfer equation of the target region tissue, determining individual parameters representing the thermal treatment sensitivity; determining target thermal treatment power according to the target temperature, the treatment time and the individual parameters of thermal treatment; and determining the temperature distribution of the tissue plane of the target region along with the time change according to the biological heat transfer equation and the individual parameters under the target thermal treatment power. Individual thermal sensitivity evaluation and target tissue temperature closed-loop control can be achieved by combining individual parameter measurement under the non-invasive condition, and the safety and accuracy of the thermal treatment process are improved.

This application provides a positioning method, apparatus, medium, and electronic device for a movable mechanism. The method includes: acquiring a first initial roll angle, a first initial pitch angle, and a first initial heading angle of an inertial measurement unit coordinate system relative to a mechanism coordinate system; performing coordinate transformation on the first initial roll angle, the first initial pitch angle, and the first initial heading angle to obtain a second initial roll angle, a second initial pitch angle, and a second initial heading angle of the mechanism coordinate system relative to the inertial measurement unit coordinate system; solving an error function to obtain a second target pitch angle and a second target heading angle of the mechanism coordinate system relative to the inertial measurement unit coordinate system; and generating an installation angle based on the second target pitch angle and the second target heading angle for positioning. This application embodiment can accurately position a movable mechanism. This application embodiment can be applied to various scenarios such as mapping, autonomous driving, intelligent transportation, and assisted driving.

This invention relates to a method for estimating the number of tags using the collision waveform of the initial frame (SOF), belonging to the field of radio frequency identification (RFID). The invention constructs a random forest offline model for tag number estimation: the initial Q-value of the DFSA algorithm is set to 0, and multiple sets of tags with known quantities are inventoried. At this time, all tags respond simultaneously, and the collision waveform of the initial frame (SOF) has a one-to-one mapping relationship with the tag quantity. The SOF collision waveform and the known tag quantity are used as the feature set and label space of the training random forest sample set, respectively, to train the random forest offline model for tag number estimation. The number of tags to be inventoried is then estimated: the SOF collision waveform of a dense number of unknown tags is used as the input to the random forest offline model, and its output is the estimated tag quantity. This invention can effectively improve the inventory efficiency of high-frequency RFID systems.

The invention discloses a subarray-level three-dimensional array element position estimation method for a towed linear array, and the method comprises the following steps: S1, carrying out the equal-interval division of array elements in the towed linear array, and obtaining a plurality of subarrays; s2, constructing a distortion model equation for projecting a distortion curve of array element position coordinates in the towed linear array to a horizontal plane and a vertical plane; s3, calculating slopes of any two attitude sensors on the distortion curve, estimating a coefficient of a distortion model equation, and solving to obtain the distortion model equation; s4, obtaining an estimated position coordinate of each array element in each sub-array by using the distortion model equation and the array element spacing obtained in the step S3; and S5, combining the estimation result of each sub-array according to the reference array element to obtain the position of the array element of the whole array. By means of the estimation method, accurate estimation of the array element position can be effectively achieved, and the problem that in the prior art, array distortion exists in a towed linear array, and then a beam forming result is reduced is solved.

This invention relates to an algorithm based on the Advantage Actor-Critic algorithm. 18 This invention relates to a method for estimating hepatocellular carcinoma dynamic parameters using F-FDG PET / CT, belonging to the fields of reinforcement learning and hepatocellular carcinoma diagnosis. The invention employs a reinforcement learning algorithm to calculate perfusion parameters, including those in blood and liver tissue, on a dual-input three-compartment model. 18 The rate constant and blood clearance rate of F-FDG 18 F-FDG is further phosphorylated to 18 The perfusion parameters were obtained by estimating the rate constant of F-FDG-6-phosphatase, the dephosphorylation rate of phosphatase, the aortic blood supply fraction, and the proportion of the measured blood volume. Utilizing the characteristics of the Advantage Actor-Critic algorithm, a neural network was introduced to guide the agent to obtain relatively accurate perfusion parameters with statistically significant differences. This invention effectively uses the Advantage Actor-Critic algorithm on a reversible dual-input three-compartment model to estimate perfusion parameters corresponding to hepatocellular carcinoma tissue and normal liver tissue, and performs statistical analysis showing statistically significant differences.

The present application relates to underwater acoustic engineering, ocean engineering, sonar technology field, especially to a kind of deep sea surface acoustic channel target distance estimation method and system using horizontal array.The method comprises: the time domain signal radiated by target sound source received through horizontal array is pretreated, and channel signal spectrum is obtained;Spatial power spectrum estimation result is obtained by channel signal spectrum, and the azimuth corresponding to surface acoustic channel sound wave and seabed reflected wave azimuth are obtained based on spatial power spectrum estimation result;The cosine of the ratio of the azimuth is obtained, and the cosine estimation value of seabed reflected wave arrival angle is obtained;The cosine template value of seabed reflected wave arrival angle obtained by sound field calculation model is matched with the cosine estimation value of seabed reflected wave arrival angle, and the estimation value of target distance is obtained.The present application is suitable for deep sea surface acoustic channel, and the calculation amount of the method is small, so the arrival time delay between different paths is not used, and there is no requirement for signal bandwidth, so the estimation of target distance can be realized quickly.