455results about How to "Fast tracking" patented technology

The invention relates to a grid connection presynchronization control method of a microgrid inverter based on droop control. When the microgrid operates in island, as a voltage source type inverter which functions as the support in the microgrid works in accordance with droop characteristic, a microgrid voltage has a deviation from a high power grid voltage; and the problem of synchronization between the microgrid voltage and the high power grid voltage during the grid connection is the key to realize smooth switchover. The grid connection presynchronization control method provided by the invention comprises the following steps: obtaining frequency and phase position information of the high power grid voltage through a three phase software phase-locked loop (SPLL); carrying out dq (Direct Quadrate) conversion to an output voltage of the inverter based on a power grid voltage phase obtained from the locked phase; subsequently carrying out PI (Physical Impairment) regulation on a q-axis component; overlapping a synchronization angle frequency output by a PI regulator with an angle frequency generated by the droop control to be used as a reference angle frequency of the output voltage of the inverter; and finally realizing the tracking and synchronization of the output voltage of the microgrid inverter to the high power grid voltage through the closed-loop control. The impact current during the grid connection is avoided effectively.

The invention relates to a multiturn absolute rotary encoder based on a rotary transformer, which is characterized in that: a sensor is displaced by taking the rotary transformer as a shaft angle; a shaft angle decoding circuit can be formed by adopting DSP as a core processor; a sine wave which can be controlled by frequency and phase in the method that the circuit is synthesized by direct digital frequency for the numerical control of an oscillator; and the sine wave is directly taken as an excitation rotary transformer signal via a power amplifier and a filter circuit; the rotary transformer signal is transferred to A / D converter after being run through a matching circuit of electronic transformer; after sampling, digital filtering and digital signal processing, the sine and cosine value for the actual angle of two channels is generated; the angle error change is tracked dynamically by the PI algorithm; the mechanical displacement of the rotating object is converted into digital shaft angle position and speed. The multiturn absolute rotary encoder based on a rotary transformer has the advantages of high tracking speed, high conversion accuracy, high reliability, simple structure, sensitive movement, low environmental condition, strong anti-interference capability, high measuring accuracy and speed voltage output.

The invention discloses antenna beam tracking device and method of a moving communication satellite communication system. The antenna beam tracking device comprises a geographical position detection device, a carrier gesture detection unit, a signal intensity detection unit, a signal conditioning circuit and a master control computer, wherein the master control computer controls a servo driver; and the servo driver controls an azimuth and pitching motor. The antenna beam tracking method comprises the following steps of: 1, initially capturing a target satellite; 2, tracking: setting initial parameters, storing and updating the initial parameters in real time, generating simultaneous disturbance random vectors, driving disturbance, measuring the intensity of received signals, estimating gradient, determining tracking error signals, regulating antenna beam pointing directions, and judging the received signals; and 3, recapturing. The invention has the advantages of simple design, low cost, system implementation without changing the hardware structure of an original tracking system, easy operation, high tracking accuracy and fast tracking speed and overcomes the defects of inconvenient operation, complex tracking step, lower tracking accuracy and tracking speed, and the like of the traditional method.

The invention relates to an automatic frequency tracking method and a system for an ultrasonic transducer. A direct digital frequency synthesizer is used as a signal source, wherein the direct digital frequency synthesizer can be an independent integrated chip and also be achieved by the method that a digital part of a DDS is integrated in a site programmable logical element FPGA and then a digital-analog converter is additionally added. The design of the invention adopts a frequency sweeping and tracking policy, and an automatic frequency controller achieved by the programmable element controls the output frequency of the DDS according to a feedback signal sampled from the self transducer end so as to achieve the full digitization automatic frequency tracking and ensure that the ultrasonic transducer work near a resonance point all the time to obtain the optimal efficiency. A phase comparator utilizes a trigger to give out the arriving time difference of two riser edge signals of two input signals I ph and V ph aiming to the sensitive characteristics of the riser edge signals, and the sequence of the riser edge signals of the two input signals I ph and V ph is given out by a Dirrect pin.

The invention discloses a method and a device for tracking featured point in an image to solve the problems such as poor effect and large amount of calculation in the prior art for tracking featured point in image. The inventive method for tracking featured point in image includes positioning featured point in a reference image to determine position of featured point in the reference image; determining a featured point searching zone rounding a featured point of the reference image as the center based on positions of the featured point in the reference image and a preset size of featured point searching zone, and using the searching zone as featured point searching zone of the present image; and defining featured point position of the present image in the featured point searching zone in the present image.

The invention belongs to the field of application of photovoltaic power generating system control technology, and relates to a maximum power tracking control method for a monopole three-phase photovoltaic grid-connected system. The method comprises the following steps of: firstly, by testing voltage and current outputted by a photovoltaic array, working out a differential coefficient k of the output power to the voltage of the photovoltaic array and a change rate delta k of the k; secondly, according to the k and an output Step1 of a fuzzy controller (an input is k and delta k, and the output is Step1), jointly determining the disturbance step length and direction of a disturbance voltage delta U which is superposed on a reference voltage U ref of a maximum power point of the photovoltaic array, and making the U ref quickly iterative and then converged at the optimal reference voltage corresponding to the maximum power point of the photovoltaic array under the current environment; and finally, realizing the quick and accurate tracking of the output voltage of the photovoltaic array on the U ref by a double closed loop control system consisting of a voltage PI controller and a synchronous vector current PI controller with feedforward compensation.

The invention relates to a deep learning-based target tracking method, a deep learning-based target tracking device and a storage medium. The method includes the following steps that: two frames of pictures are continuously read; a target region of the former frame and a search region of the current frame are set and cut, when the search region of the current frame is set and cut, whether an object is stable when the object moves fast is judged, so that a center point position is set, and the search region can be obtained; the target region and the search region are inputted to a convolutional neural network, calculation is performed, so that the target region of the current frame can be obtained; calculation is performed, the inter-frame displacement of the current frame relative to the former frame is obtained; and whether the current frame is the final frame is judged, so that whether iterative target tracking is performed further is judged. According to the deep learning-based target tracking method, the deep learning-based target tracking device and the storage medium of the present invention, the prediction of the center point position of the cutting region of the current frame can be realized through judging the speed of the movement of the target object in the image. Compared with an existing algorithm, the method can improve target tracking accuracy and target coincidence degree with original high tracking speed maintained, and has good tracking robustness.

A client station in a wireless local area network (WLAN) communication system includes a beam commutation algorithm and a smart antenna responsive to the beam commutation algorithm for selecting one of a plurality of directional antenna beams. The smart antenna is configured as a virtual omni-directional antenna by using a commutation of switched directional antenna beams. A switched directional antenna system that performs a commutation sequencing can be blind to environmental conditions and changes.

A Method and System for Emitter Identification Using Transmission Signatures is disclosed. Also disclosed is a system that is able to take in the undemodulated IF of the receiver and perform identification algorithms on that data. The system is further able to perform these functions in real-time and present the operator with an intelligent evaluation as to the identification of an emitter, or the presence of a new emitter. Still further, the system is capable of being fully automated to reduce the processing time to react to the results of the emitter identification. Furthermore, the present invention can feasibly remotely control the emitter identification system over a network and collect the same information from similar systems. In this way, a far more efficient System can be achieved wherein emitters can be determined, tracked, or monitored more quickly from a centralized command facility.

The invention provides a segmentation self-adapting hill climbing method and a system thereof applied for tracing maximum power of a photovoltaic cell. The method comprises: finding the zone of the current power by partitioning the output power of the photovoltaic cell and comparing power difference of two adjacent moments with a set value; then, adjusting duty cycle to measure the power of the next moment until the maximum power point is found. The system of the invention comprises a photovoltaic cell, a DC / DC converter and a plumbic acid storage battery which are connected by circuits in sequence, wherein, a circuit between the DC / DC converter and the plumbic acid storage battery is provided with a voltage detecting module and a current detecting module, the output ends of the voltage detecting module and the current detecting module are respectively connected with a microprocessor, and the output end of the microprocessor is connected with the DC / DC converter via an isolation / driving circuit. The invention quickens the tracing speed of the maximum power point, improves the anti-interference performance of the system, quickens the self-optimizing process of the maximum power point of the system and decreases the oscillation of the system at the maximum power point.

The invention mainly relates to a design method of a reinforcement learning based optimal tracking controller for a model unknown servo system. The design method of the reinforcement learning based optimal tracking controller for the model unknown servo system is introduced mainly on the basis of a simplified reinforcement learning evaluation-execution structure with a high-order neural network approach method, and the optimal tracking control solution speed of a motor is increased. As for the model unknown servo system, firstly, homeostatic control is solved with a multilayer neutral networkintelligent identification system model; performance indexes are given, and a high-order neutral network approach optimal performance index function is applied; an HJB (Hamilton-Jacobi-Bellman) equation is established according to an approximate performance index function and the identification system model, and the optimal feedback control of the servo system is solved. The optimal tracking control is calculated according to the solved homeostatic control and optimal feedback control, so that tracking error accumulation values and system energy consumption are minimized simultaneously while load rotation angle and rotation speed rapidly track given signals.

The invention relates to an intelligent fusion method for depth images based on area shades and red green blue (RGB) images. The intelligent fusion method is characterized comprising the steps of collecting the depth images and the RGB images of the same scene at the same moment, selecting large area invariance associated characteristics of the depth images and the RGB images; utilizing the large area invariance associated characteristics to perform image registration; setting an interested depth range in the depth images after registration, and obtaining new depth images only containing the interested depth range; generating the shades for target objects; and performing fusion on the shades and the registered RGB images. The intelligent fusion method has the advantages that the fused images contain depth information and color and texture information, algorithm complexity is reduced, accuracy in target object recognition is greatly improved, the detection speed and the tracking speed are improved, and registration precision is enhanced.

An echo canceller includes an initial delay estimator producing a reference signal containing an identified frequency component masked by means of frequency masking effect to output the reference signal on an echo path, and detecting, from a sending voice signal, an echo component of the identified frequency component derived from the reference signal. The estimator finds an initial delay amount on the echo path on the basis of a forming timing of the reference signal containing the identified frequency component and a detection timing of the echo component in the identified frequency component in the sending voice signal. The echo canceller includes a delay circuit for delaying a received voice signal by the initial delay amount on the echo path obtained from the estimator to supply a resulting signal to a pseudo echo generator.

The invention provides a maximum power point tracking method based on efficient adaptive perturbation and observation. By the aid of the maximum power point tracking method, the problem that the step size used in a traditional perturbation and observation method in the photovoltaic-battery maximum power point tracking technology is difficult to balance, completely adaptive perturbation can be realized, and tracking speed, stability precision and universality of a system are high. The maximum power point tracking method with a basic principle includes that computing continuous output power values of a photovoltaic array according to filtered voltage and current signals; generating error signals according to changes among power signals; generating adaptive perturbation voltage values via a PI (proportional plus integral) controller; and finally generating a reference value of voltage of the photovoltaic array according to the basic principle of perturbation and observation. An error signal of an actual value and the reference value of the voltage of the photovoltaic signal is computed, and a duty cycle signal d required by a DC / DC converter is generated by another PI controller, so that on and off time of each power switch tube of a phase-shift full-bridge converter is controlled, power outputted by the photovoltaic array is adjusted, and the maximum power output point of the photovoltaic array can be tracked.

Provided is a universal gravitation neural network based wind power system MPPT control method. According to the method, on the basis that a large amount of power-rotation speed-wind speed samples are established, a universal gravitation neural network prediction model of wind speed is established and is utilized to perform wind speed estimation, then an optimum tip speed ratio method is adopted to predict an optimal fan rotation speed corresponding to a maximum power point, the fan rotation speed is adjusted to be the predicted optimal fan rotation speed, the rotation speed is used as an initial value, and a duty ratio perturbation and observation method is adopted to set perturbation step length for tracing the maximum power of a fan. The estimation method is adopted to obtain the wind speed without a wind speed sensor, the control cost of the system can be effectively saved, and the reliability of the system can be improved. The method utilizes a universal gravitation search algorithm to optimize a neural network model, and wind speed estimation accuracy can be effectively improved. In addition, the universal gravitation neural network based wind power system MPPT control method further has the advantages of being high in tracing speed and capable of improving the powder generating efficiency of the fan.

An embodiment of the invention provides a positioning method and an electronic device. The method includes the steps: performing first distortion correction for a first image according to a first distortion correction rule to obtain a second image; performing second distortion correction for a second image according to a second distortion correction rule to obtain a third image; acquiring M image calibration coordinates in the third image and N projection calibration coordinates in a projection area; determining the mapping relation between an image coordinate and a projection coordinate according to the M image calibration coordinates and the N projection calibration coordinates; analyzing the third image to obtain a first light spot image coordinate of a first light spot in the third image; and acquiring a first light spot projection coordinate of the first light spot in the third image according to the mapping relation between the image coordinate and the projection coordinate. Therefore, the method solves the technical problems that images are unstably calibrated, and the mapping relation between an image coordinate and a mapping coordinate is inaccurate in the prior art.

The invention relates to a multi-peak target tracking method with fusion of background information. According to the method, the background information near the target is utilized, the background information of the same size is extracted from eight concrete positions of upper left, upper, upper right, left, right, lower left, lower and lower right of a current frame target search box to act as candidate target search boxes, the response of the candidate target boxes is computed by using the circulation matrix of the correlation filter tracking method and the Gaussian kernel function, and the classifier parameters are trained and updated so that the success rate in case of rotation change of the target can be enhanced. Existence of the interference situation of similar targets is considered, and the multi-peak target detection strategy, i.e. the possibility that the target is located in any one of multiple peaks of the target output response diagram, is utilized so that the accuracy oftarget tracking can be enhanced.

The invention discloses an automatic navigation system based on camera detection, a control method of the system and a vertical balance car. The system comprises a vertical balance data collection module, a camera data collection module and a signal processing and control module, wherein the vertical balance data collection module and the camera data collection module are connected with the signal processing and control module, the vertical balance data collection data obtains present attitude angle data of the vertical balance car, the camera data collection module collects gray-level image data of a runway, and the signal processing and control module collects, stores and processes the gray-level image data of the runway, the present attitude angle data of the vertical balance car, and present speed and differential speed data of the vertical balance car, and controls the balance of the vertical balance car according to the present attitude angle data of the vertical balance car. Thus, the road condition in front can be effective predicted, prediction can be controlled more effectively, and the control precision is improved.

The invention discloses an automatic segmenting and tracking method of a multiple-video moving target, which can realize real-time automatic segmentation and accurate tracking of a plurality of video moving targets under static background and comprises the following steps: firstly, inputting a video image; secondly, performing the self-adaptive background modeling; thirdly, performing the airspace filtering to a background difference image; fourthly, performing the self-adaptive real-time threshold value and extracting the moving target outline; fifthly, getting the moving target mass center and marking the mass center; and sixthly, tracking the moving targets. The automatic segmenting and tracking method is mainly applied to the substrate video processing technique based on the video research and the video monitoring of the content.

The invention discloses a system and a method for tracking motion communication two-beam pseudo monopulse. The system comprises a plat antenna, four low-noise amplifiers, four power dividers, a down converter I, a tracking beam forming unit, a down converter II, a main controller, a beacon receiver, an attitude detecting unit, an angular rate detecting unit and a beam controller, wherein the down converter I is respectively connected with one output end of the four power dividers; the tracking beam forming unit is respectively connected with the other output end of the four power dividers; the down converter II and the main controller are connected with the tracking beam forming unit; the beacon receiver, the attitude detecting unit and the angular rate detecting unit are connected with the down converter II; the beam controller is controlled by a main controller; and the antenna is divided into four quadrant submatrixes. The method comprises the following steps of: detecting signals in real time, uploading the signals synchronously, generating two beams, and communicating and tracking by two beams synchronously. The invention has the advantages of simple design, convenient use and operation, high tracking precision, high tracking speed, simplicity and easy implementation, and enables the communication motion system to be free from the constraint of the main station and always track the target satellite by adopting the two beams.

The present invention relates to a method for realizing single-phase phase-locked loop by adopting software, comprising the following steps of: constituting an input signal in an alpha-beta coordinate system with a standard signal as a reference (1); carrying out PI adjustment through the output of dq0 conversion q axle component based on the instantaneous reactive power theory, carrying out frequency correction through the output of the PI adjustment step, using an output signal of the frequency correction step as a reference, and carrying out phase correction through using the integration step (2); designing a low pass filter and ensuring the speed and the accuracy of the tracking of the phase-locked loop (3); speeding up the calculation by adopting 16 bit fixed point TMS320C2812DSP programming (4). The method adopts closed-loop control, which is high in stability and quick in tracking speed, with the transient response time less than 0.04s and wide frequency range of the locked phase between about 45 and 55Hz, is not interfered by the harmonic waves and the twinkling fluctuation of the system voltage or current, can accurately and quickly track the fundamental wave frequency and the phase information of the voltage and current in an electric power system, and provides system synchronous frequency signals for active filters and dynamic voltage adjustors, etc.

An antenna-receiver communications system and method is provided to mechanize multibeam mobile antenna-receive subsystems. Digital beam forming for modern wideband mobile communications systems is provided. In an aspect, subsystems can simultaneously receive, acquire, track and output a multiplicity of signals from sources of different locations using a single antenna aperture from a mobile platform. The angle of arrival of a signal of interest is continuously determined. Individual phased array antenna output channels are phased aligned as required by the phased array equation and monopulse signal processing. Angle sensing and beamsteering are separated from antenna channel coherent summation. Thus, the angle sensing and beamsteering functions are not required to be computed at the data rate, but can instead be computed at a rate necessary for the beam acquisition and beam tracking function speed requirements. Signal processing computational load and system cost is reduced as compared to current systems.

The invention discloses a particle filter and perceptual hash-based video target tracking method which comprises the following steps: 1) selecting a target to be tracked from an original image as a target area, extracting a perceptual hash characteristic of the target area as a template feature, and initialization positioning a weight particle set; 2) performing a state coordinate prediction for the weight particle set and labeling the prediction area; 3) extracting the perceptual hash characteristic for each predicting particle area, and calculating a similarity degree of the predicting particle area and the target area; 4) according a position contribution of a distance from the target and a similarity degree refreshing particle weight of the perceptual hash characteristic, adopting a minimum variance to estimate and obtain a new target area; and and 5) according the size of the weight and a resample estimation value, obtaining the weight particle set of a next frame, and repeating from the step 2 to the step 4 till an end of all video sequences. The particle filter and perceptual hash-based video target tracking method disclosed by the invention is high in efficiency, and can realize fast and effective tracking on the premise of great illumination variance and change of the target scale.

The invention discloses a multi-beam pointing on-orbit calibration method suitable for a high-throughput satellite. A satellite-borne on-orbit calibration system comprising an antenna to be calibrated, a radio frequency channel, a tracking receiver, an antenna controller and an antenna driving mechanism is used; a single-pulse tracking system is adopted; and aiming at the current situation that the high-throughput satellite adopts a multi-beam design, the beam width is relatively narrow and the gain of a coverage area is easily influenced by a pointing deviation, a calibration signal of a ground beacon station is received, and antenna beam pointing is subjected to closed-loop automatic correction, so that multi-caliber multi-beam antenna pointing is calibrated, and the requirements of thesystem on beam seamless coverage and the gain of the coverage area of the satellite are met.

An antenna-receiver communications system and method is provided to mechanize multibeam mobile antenna-receive subsystems. Digital beam forming for modern wideband mobile communications systems is provided. In an aspect, subsystems can simultaneously receive, acquire, track and output a multiplicity of signals from sources of different locations using a single antenna aperture from a mobile platform. The angle of arrival of a signal of interest is continuously determined. Individual phased array antenna output channels are phased aligned as required by the phased array equation and monopulse signal processing. Angle sensing and beamsteering are separated from antenna channel coherent summation. Thus, the angle sensing and beamsteering functions are not required to be computed at the data rate, but can instead be computed at a rate necessary for the beam acquisition and beam tracking function speed requirements. Signal processing computational load and system cost is reduced as compared to current systems.

The present invention provides a maximum power point tracking method and device and a photovoltaic power generation system. The maximum power point tracking method comprises: sampling present voltage and present current of a photovoltaic array; obtaining present power based on the present voltage and the present current; using difference between the present power and power for previous sampling time as present perturbation power, and based on ratio of the present perturbation power to perturbation power for previous sampling time, obtaining gradient perturbation voltage step ratio; obtaining perturbation voltage step based on the gradient perturbation voltage step ratio and voltage difference between the present voltage and the voltage for previous sampling time; and controlling output voltage based on the perturbation voltage step.

The method discloses a robust video object tracking method, and the method comprises the steps: sampling a candidate target particle based on the particle filter importance sampling principle; filtering out divergent particles based on the cosine similarity between the candidate target particle and a former tracking result; representing the screened candidate target particle based on a template dictionary linearly; building a low-rank sparse mathematic model of a linear coefficient matrix; solving a coefficient matrix based on an incorrect lagrangian multiplier optimization algorithm; selecting an optimal candidate object according to a discrimination function to serve as a tracking result; and updating the template dictionary in an on-line manner. The robustness of the method guarantees that the method can meet various types of challenges, and achieves the accurate tracking of a target in a video. The method solves a problem of inaccurate tracking and drift of the target in the video, wherein the problem is caused by illumination variation, scale change, shading, deformation, movement fuzzy, quick movement, rotation, background clutter, low resolution and others.

The invention relates to the field of solar energy photovoltaic power generation, and discloses a photovoltaic maximum power point tracking control method and device based on a grey wolf algorithm. The duty ratio of a transducer serves as a grey wolf, and the maximum power of a photovoltaic array under the condition of partial shading is tracked by means of the grey wolf optimization algorithm. The voltage output and the current output are relatively stable, the tracking speed is fast, the dynamic response oscillation is small, the problem of steady state oscillation does not exist, and the efficiency of the a photovoltaic power generation system is effectively improved.

The invention discloses a variable pitch control method of a wind generating set. The method includes the steps: acquiring real-time rotating speed of a wind wheel and real-time pitch angles of bladesof the wind generating set; calculating variable pitch speed of the blades by a proportional differential control algorithm according to the real-time rotating speed and the real-time pitch angles; controlling variable pitch rotation of the blades according to the variable pitch speed. Compared with a traditional proportional integral control algorithm, the pitch angles cannot be converted into the variable pitch speed, the variable pitch speed is directly acquired, so that delay and indeterminacy increased by a converting link are avoided, tracking of a system is accelerated, the dynamic response capability of a variable pitch system of the wind generating set is improved, the method solves the problem of excessive speed of the wind generating set under gale and strong turbulence, so that generation of an extreme load is avoided, fatigue damage to the wind generating set is reduced, and availability and the generating capacity of the wind generating set are improved.