16 results about "Step frequency" patented technology

The invention discloses a method and a device for analyzing and correcting influence of phase errors between sub-bands of step-frequency ultra-wideband SAR (Synthetic Aperture Radar) data, and belongs to the technical field of synthetic aperture radar signal processing. The method comprises the following steps: carrying out amplitude error estimation and compensation on each sub-band echo signal; preliminarily estimating a phase error by using the partial overlapping characteristic of the sub-band spectrum; performing distance compression on each sub-band signal; establishing an optimization model based on a maximum norm, and solving an accurate phase error by taking the preliminarily estimated phase error as an iteration initial value; carrying out sub-band splicing and distance resolution compression on the sub-band signals after phase error compensation; and finally, a corrected SAR image is obtained through a CS imaging algorithm. According to the method, extra calibration signals are not needed, high-precision phase error correction can be achieved only based on echo data, the calculation efficiency is high, and the method is suitable for a high-resolution SF-SAR system.

The invention discloses a self-adaptive dynamic calibration PDR positioning method based on a low-cost sensor. The method comprises the following steps: preprocessing original inertial measurement data acquired from a built-in sensor of a smart phone; based on the preprocessed data, estimating a pedestrian course angle by adopting a self-adaptive magnetic interference suppression attitude fusion algorithm; based on acceleration data in the preprocessed data, performing gait detection by adopting a dynamic threshold peak detection method, and adjusting a detection threshold in real time according to sensor data fluctuation; performing fast Fourier transform on the acceleration data, extracting a frequency corresponding to a maximum amplitude in a frequency domain as a stride frequency, and calculating a step length based on the stride frequency; and pedestrian position calculation is realized by combining the initial position, the course angle, the gait mark and the step length of the pedestrian. The method provided by the invention has stronger robustness and higher positioning precision.

Embodiments are disclosed for real time estimation of DoT. In some embodiments, a method comprises: obtaining inertial acceleration data from a motion sensor of a mobile device worn or held by a user; computing a frequency spectrum of the acceleration data to generate horizontal and vertical frequency components at a step frequency of the user; constructing an acceleration trajectory of the horizontal frequency components in a horizontal reference frame, the horizontal frequency components forming an ellipse in the horizontal reference frame; determining a maximum radius vector of the ellipse; determining an angle to DoT based on the maximum radius vector; disambiguating a sign of the angle; and determining the disambiguated angle as the DoT.

The invention discloses a dual-mode millimeter-wave radar channel amplitude-phase distortion compensation method and device and a storage medium, and the method comprises the steps: obtaining a transmitting-receiving control parameter, and carrying out the analysis of the transmitting-receiving control parameter, and obtaining a transmitting waveform parameter and a local oscillator waveform parameter; starting from the low-frequency end of the working bandwidth of the system, adjusting a transmitting waveform parameter and a local oscillator waveform parameter, and generating paired single-tone correction signals as a transmitting pre-driving signal and a local oscillator pre-driving signal respectively; generating an analog intermediate frequency signal according to the transmitting pre-driving signal and the local oscillator pre-driving signal, and extracting a distortion amplitude phase value corresponding to the current frequency point from the analog intermediate frequency signal; controlling the frequency of the paired single-tone correction signals to be gradually increased according to a preset step length, and obtaining distortion amplitude and phase values of a plurality of frequency points; performing interpolation fitting on the distortion amplitude-phase value, and calculating an equalizer coefficient; and step frequency is adjusted and calculation is repeated until all equalizer coefficients are obtained for performing dual-mode millimeter wave radar channel amplitude phase distortion compensation.

The invention provides a fuzzy ranging reconstruction method and system, and the method comprises the steps: modulating the pulse frequency of seed light transmitted by a laser radar through employing a floating step frequency modulation strategy, randomly selecting the transmission time interval between adjacent seed light in a prefabricated set, and enabling the time modulation amounts between the adjacent seed light to be unequal, the emitted seed light carries ranging noise; a seed light sequence of pulse emission and a return light sequence reflected by a target are stored respectively, the seed light sequence is the time difference between the current seed light and the previous seed light, and the return light sequence is the time difference between the current return light and the nearest seed light; and according to the distance measurement continuity and frequency modulation step characteristics of the return light sequences, through sequence segmentation, period hypothesis and verification and mask intensity calculation, emission periods to which the return light sequences belong are automatically judged, and a real distance value is reconstructed. According to the invention, full-automatic cross-cycle identification without manual intervention is realized, and the integrity and accuracy of the point cloud data are improved.

The present application relates to the technical field of intelligent wearing device, particularly relates to a step frequency guiding method and a wearing device, wherein the step frequency guiding method is applied to the wearing device, the wearing device comprises a vibration module, the vibration module comprises a plurality of vibration units which are independently arranged and controlled, the step frequency guiding method comprises receiving information to be expressed; generating a vibration instruction set according to the information to be expressed based on a preset vibration rule; and driving one or more vibration units in the vibration module to vibrate according to the vibration instruction set. The main purpose of the present application is to provide a step frequency guiding method, which aims to provide multi-meaning vibration information for users.

The invention relates to the technical field of data interaction, in particular to an internet of things interactive grid control method based on in-shoe inertial measurement, which comprises the following steps: setting an inertial measurement module in an intelligent shoe and establishing communication with a networking terminal running an application program; collecting a multi-axis angular velocity and a multi-axis acceleration, and carrying out low-pass filtering, zero offset estimation deduction and gravity-based coordinate calibration; adaptive sliding window discrete Fourier transform is adopted for the angular velocity to extract spectral peaks to obtain a stride frequency sequence, and window adjustment is carried out along with stride frequency changes; determining a zero-speed interval threshold value according to the stride frequency, calculating test statistics fusing angular velocity energy and acceleration stability, and comparing to output a foot static interval; suppressing attitude drift and segmenting effective trampling by using a static interval, extracting angular velocity time sequence characteristics, and comparing the angular velocity time sequence characteristics with a template library to determine a target grid; a direction instruction is generated, the center is homing, and the periphery is moving; and sending to the terminal, mapping as a direction key, and performing direction-changing gating by homing to realize continuous movement control. According to the invention, the limitation of the gyroscope when the game terminal is applied in the shoe can be solved, and the limitation of the intelligent shoe game terminal and scene can be solved.

The invention discloses an ultra-high-speed target imaging method and system based on double-step frequency phase cancellation. According to the method, the characteristic that two groups of stepping frequency signals with different repetition periods can be converted to a frequency domain on a slow time axis is utilized, and the stepping frequency signals are combined with a phase cancellation operator constructed by the frequency domain, so that a primary phase term and a secondary phase term caused by motion can be eliminated on the premise of keeping system parameters consistent; meanwhile, sampling envelope walking under the high-speed condition can be effectively restrained, so that stable correction is still achieved under the high-speed scene, the energy focusing capacity is improved, and the high-performance imaging method based on the frequency domain phase cancellation technology is obtained. According to the method, range image offset, image waveform divergence and sampling envelope walking can be effectively inhibited under the condition of ultra-high-speed motion, the speed application range of double-pulse-group stepping frequency imaging is expanded, and the target imaging focusing performance and the positioning precision are improved.

The application discloses a kind of robust frequency-modulated stepped frequency ISAR imaging radar velocity estimation methods, belong to radar technical field, first construct multiple frames frequency-modulated stepped frequency data model;Again, the velocity estimation and compensation of rough accuracy are realized using the same frequency point offset estimation of multi-frequency point synthesis;Then, the high-resolution imaging of the coarse resolution distance unit where the special point is located is obtained by the IFFT of intra-frame sub-pulse dimension, and the high-precision velocity estimation and compensation are realized using the high-resolution image of multiple special point synthesis;Finally, ISAR imaging is realized through the FFT between frames.The application realizes the estimation and compensation of velocity gradually using two-step method, first realizes the estimation and compensation of large motion amount by rough estimation, then realizes the residual motion estimation and compensation of high precision by synthesis high resolution;Offset estimation is realized using envelope cross correlation, motion parameter estimation is realized using offset fitting, and the amount of calculation is small;The robustness of algorithm is improved using the characteristics that multiple frequency points are not easily disturbed simultaneously, and the robustness of high-resolution velocity estimation is improved using the motion identity of multiple special points.

Systems and methods are provided and include a radar system that transmits radar signals within frames having radar chirps. The radar chirps have a stepped frequency waveform such that the initial and end frequencies are changed for subsequent chirps and have a constant pulse repetition period between chirps. The radar system performs range fast Fourier transform (FFT) processing and Doppler FFT processing on receive values corresponding to reflected signals from an object. The radar system estimates range and range-rate information about the object based on range FFT values and Doppler FFT values using a signal model and determines information about the object based on the estimated range and range-rate information. The signal model includes (1) a fast-time dimension term corresponding to samples within a radar chirp and (2) a slow-time dimension term corresponding to individual radar chirps within the frame, with the slow-time dimension term including a second degree term.

A racehorse movement modal recognition method and system based on centimeter-level real-time trajectory, the method first acquires the three-dimensional coordinate sequence when the horse moves, and extracts the kinematic characteristic parameters; then judges the horse movement state, and classifies the horse gait modal; then acquires the absolute stride length of the horse horizontal displacement trajectory, constructs the stride / step frequency ratio factor, and determines the corresponding normal fluctuation interval; finally, the current stride / step frequency ratio factor of the horse is acquired and compared with the corresponding normal fluctuation interval to determine the horse gait health state; the invention uses centimeter-level real-time absolute position change for modal analysis, effectively avoids false positives caused by inertial sensor nonlinear impact and attitude jitter, and through the construction of stride / step frequency ratio factor and the corresponding normal fluctuation interval by sub-modal, early warning of fatigue state and precise detection of gait abnormality are realized, and the accuracy of gait modal recognition is effectively improved.

The application discloses a kind of power electronic transformer off-state partial discharge measurement method and device, it is related to power electronic equipment detection technical field, by high-frequency impedance device is accessed into measurement system to complete calibration coefficient calculation, again access power electronic transformer and according to preset frequency step interval set step frequency point, point by point adjustment to ideal compensation state and record parameter, then start high-frequency no partial discharge excitation source sweep, maintain compensation and voltage stability and collect electric signal, capture partial discharge pulse signal, finally according to the series of steps of acquisition data calculation and the impedance module value of calibration coefficient correction, calculate complex impedance parameter and extract partial discharge characteristic quantity, reach in power electronic transformer off-state, realize the integrated measurement of partial discharge characteristic quantity and complex impedance parameter precision, synchronization.

A running method analysis device, a running method analysis method, and a computer-readable storage medium are provided. In the running method analysis device, a first step frequency acquisition unit (76) acquires a step frequency at a first running speed as a first step frequency with respect to running of a subject. A second step frequency acquisition unit (77) acquires a step frequency at a second running speed different from the first running speed as a second step frequency with respect to running of the subject. A determination unit (80) determines which of a plurality of running pattern types including a stride pattern and a step frequency pattern the running of the subject conforms to, based on a magnitude of a difference between the first step frequency and the second step frequency with respect to a difference between the first running speed and the second running speed. A result output unit (92) outputs a result of the determination.

The application discloses a variable mode decomposition method for step frequency continuous wave signal noise reduction, and belongs to the field of signal modulation. The method solves the problem that the intensity of noise components in the existing spectrum synthesis is much higher than that of effective signals, and the effective suppression cannot be obtained. The method comprises the following steps: collecting a step frequency continuous wave echo signal, and decomposing the step frequency continuous wave echo signal into a plurality of independent single frequency signals; performing variable mode decomposition on each single frequency signal to obtain a plurality of intrinsic mode functions; screening modes with the same center frequency as the frequency of the effective signal as effective signal modes, and screening the remaining modes as noise modes; calculating the maximum information coefficient MIC between the effective signal modes and the noise modes; iteratively optimizing the parameters of the variable mode decomposition based on a Bayesian optimization method until the MIC value of the effective signal modes and the noise modes is lower than a set threshold; retaining the effective signal modes, and reconstructing a step frequency continuous wave signal after noise reduction. The application is applied to the fields of high-resolution target imaging and ranging.

The present application relates to the technical field of power control, in particular to a dispersion control method, device and program for a direct current controller. Different body weight users generate different pressure on the treadmill, which affects the power required by the direct current controller. In order to accurately determine the power value at the next moment, the historical pressure time series data and the current power value of the user are obtained. Under the natural gait of the user, the pressure data changes with the lifting and landing of the foot, so according to the change trend of the historical pressure data, the gait cycle data segment is periodically divided. Then, the load characteristic value is determined by comprehensively considering the pressure fluctuation and numerical characteristics of all cycle data segments, which reflects the gait attribute of the user. At the same time, the step frequency also affects the power output, so the step frequency coefficient is determined by comprehensively considering the length characteristics of the cycle data segment. Finally, the current power is adjusted based on the load characteristic value and the step frequency coefficient to obtain the power value at the next moment. This predictive adjustment makes the power control of the treadmill more intelligent, improves the use safety and running stability.

The invention relates to an on-the-way running rhythm analysis method and device based on stride change and a medium, and belongs to the technical field of running rhythm analys.The method comprises the steps that whether an athlete is in an on-the-way running stage or a sprint running stage is judged, and the frame number corresponding to the first on-the-way running stage and the frame number corresponding to the first sprint running stage are recorded; calculating the ground clearance of each frame of the left foot and the right foot, and calculating the correction distance of the left foot and the right foot; calculating left foot and right foot state scores, and calculating the effective stride length of each frame; calculating a stride frequency score and a stride stability score; judging whether the running width rhythm is stable or not; calculating a gait trigger score and a gait time score, and calculating a stride frequency stability score; judging whether the running frequency rhythm is stable or not; and when the running width rhythm and the running frequency rhythm on the way are unstable, judging that the rhythm of the athlete needs to be improved in the running process on the way. According to the invention, dynamic and personalized running rhythm analysis guidance is provided for athletes.