32 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 provides a design method of an adaptive signal conditioning system of a flexible gait sensor, and belongs to the technical field of flexible sensor signal conditioning. The method comprises the following steps: establishing a gait feature database by analyzing gait features in different states; obtaining design reference values of a gain G and a time constant according to stride frequencies and signal amplitudes of different gait states and requirements on dynamic response characteristics, and calculating corresponding accurate RC values under different gait states through mathematical relationships between the design reference values and capacitors and resistors in a charge amplifier and a low-pass filter circuit; carrying out simulation verification, and carrying out iterative optimization on the key parameters according to a result; designing a complete hardware system, and completing the design and layout of a PCB; and finally, circuit parameters are dynamically adjusted based on a pre-stored stride frequency RC mapping relation, and dynamic adaptive adjustment of the stride frequency is realized. According to the invention, high-precision conditioning output of mV-level weak signals is realized, the precision and stability of signal acquisition are remarkably improved, and the application scene of the system is expanded.

The invention relates to a low-voltage cable fault diagnosis positioning method and device based on stepping frequency wave reflection. The low-voltage cable fault diagnosis and positioning method based on stepping frequency wave reflection comprises the following steps: inputting a stepping frequency signal to a first end of a cable, and receiving a reflection signal of the stepping frequency signal; establishing an equivalent parameter model of the to-be-detected cable; calculating a reflection coefficient L of the first end according to the equivalent parameter model and the reflection signal; judging whether the cable has a fault according to the L; if gamma is equal to 0, the cable is healthy, and if gamma is not equal to 0, the cable has a fault; and determining the fault distance according to the time difference between the step frequency signal and the reflection signal. By injecting the detection signal into the to-be-detected cable and extracting the reflected wave, local insulation damage of the low-voltage cable can be effectively detected, potential fault points can be found in time, accidental power failure and accidents caused by insulation damage can be prevented and reduced, and the safety of a power grid is improved.

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.

A gait analysis device, a gait analysis method, and a gait analysis program. In the gait analysis device, a step frequency change with respect to a running speed is acquired with respect to running of a subject. A step length change with respect to a running speed is acquired with respect to running of the subject. A determination section (80) calculates a principal component score from the slope of the step frequency change and the slope of the step length change of the subject, based on a principal component analysis model that is generated in advance based on measured values of a plurality of runners, and determines which of a plurality of gait types including a stride type and a step frequency type the running of the subject conforms to, based on the calculated principal component score.

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.

A metronome module is electrically connected with a Bluetooth module, audios of the metronome module and the Bluetooth module can be output from an audio cable to the earphone for playing, the metronome module is provided with metronome key modules, and the metronome key modules at different positions control different functions of the metronome module. The Bluetooth module is provided with Bluetooth key modules, the Bluetooth key modules at different positions control different functions of the Bluetooth module, and the metronome module can adjust metronome sound to be matched with the running stride frequency of a sporter to be mixed with song audio of the Bluetooth module to be played in the earphone. The rhythm of music and the stride frequency of running are naturally coordinated, the metronome module can freely adjust the frequency to help exercise, the Bluetooth module can play favorite songs, a runner can feel coordinated and natural in the exercise process, the exercise interest of people can be stimulated, and the exercise enthusiasm is improved.

The utility model relates to the field of radio transceiving, and discloses an ultra-wideband extremely-small-step frequency hopping frequency synthesizer module. According to the invention, the high-speed dot frequency array divides an ultra-wideband frequency 9-18GHz signal into 8 segments, and the 8 segments are respectively shifted and converted to 1000-2200MHz for frequency and phase discrimination, so that the phase discrimination frequency is greatly reduced, excellent phase noise can be obtained, and ultra-wideband frequency coverage is realized at the same time. The adopted high-speed dot frequency phase-locked array is low in phase noise and large in frequency span coverage, the switching time is short through a high-speed switch, large-range fast frequency hopping can be achieved, and powerful support is provided for prolonging the large-range frequency hopping time of a whole circuit system. A DDS direct digital frequency synthesis circuit is adopted, near-end stray is low, high-frequency resolution is provided, and extremely low frequency stepping can be achieved. And the frequency hopping speed is high and reaches below 1uS, so that the rapid frequency hopping of the frequency synthesizer system can be realized.

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 invention relates to the technical field of wireless, and provides a target sensing method, device and equipment, a storage medium and a program product, and the method comprises the steps: transmitting a stepping frequency signal use application to a network manager before a sensing track forming process is completed based on a sensing signal; the stepping frequency signal use application is used for indicating the network manager to carry out resource allocation of a frequency division adjacent station; transmitting a step frequency signal; determining size information of a target corresponding to the sensing track based on an echo signal of the stepping frequency signal; and determining type information of the target corresponding to the sensing track based on the size information of the target corresponding to the sensing track and the obtained radar cross-sectional area of the target corresponding to the sensing track. According to the method, the type information of the target corresponding to the sensing track can be accurately identified, the false alarm elimination effect is improved, and the false alarm verification confidence coefficient of low-altitude target sensing can be further improved.

A clutter suppression method uses the local oscillator frequency hopping characteristics of high repetition rate stepping frequency signals, sets the receiver bandwidth and local oscillator frequency hopping interval that meet the conditions, and combines the receiver gating filter to effectively suppress the clutter outside the target echo distance range. Without additional hardware and operation processing, it is convenient to realize, beneficial to subsequent signal processing requirements, improves the visibility level under clutter, enhances the target detection ability, and has good engineering application value.

This application discloses a step frequency measurement method, device, electronic device, and medium. The method includes: determining N distance values ​​between the electronic device and the ground based on N sets of times; each set of times corresponds to one distance value; each set of times includes a first time and a second time, the first time being the time when a first UWB pulse is emitted, and the second time being the time when a second UWB pulse is received, the second UWB pulse being the UWB pulse reflected by the ground from the first UWB pulse; determining the step frequency information of the carrier of the electronic device according to the time interval between the third times corresponding to two of the N distance values; the N distance values ​​correspond to M measurement cycles, one measurement cycle corresponding to at least one distance value among the N distance values, the two first distance values ​​including: the maximum or minimum distance value among at least one distance value corresponding to two adjacent measurement cycles in the M measurement cycles; a third time is determined based on a set of times corresponding to a first distance value.

The invention relates to a moving speed determination method and device, electronic equipment and a storage medium. The moving speed determination method comprises the steps of obtaining an acceleration signal of the electronic equipment, determining a target stride frequency and a first step length of the acceleration signal in the main axis direction, determining an initial error parameter of the first step length according to a preset stride frequency interval corresponding to the target stride frequency, and determining the moving speed of the electronic equipment according to the target stride frequency, the first step length and the initial error parameter. And determining the initial moving speed of the electronic equipment, and correcting the initial moving speed to obtain the target moving speed. According to the method, the initial error parameter of the first step length adapts to different motion states, real-time correction is carried out on the basis of the initial error parameter, the influence of the motion state change on the speed estimation value can be avoided, and the real-time performance and accuracy of the speed estimation result are effectively 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 discloses a method, a device, equipment and a medium for intelligently adjusting the track speed of a treadmill, and relates to the technical field of treadmill speed regulation, and the method comprises the following steps: receiving position data sent by a laser radar sensor, and determining the stride frequency and stride difference of a runner according to the position data; determining a target speed according to the stride frequency and the stride difference; and adjusting the speed of the treadmill track to the target speed. The stride frequency and stride difference of a runner are captured in real time through the laser radar, and direct dynamic association between the human body motion intention and the track speed is established. The step change trend is accurately quantified through the step difference, so that the system prejudges the speed regulation requirement before the gravity center of a runner shifts, and near-real-time response is achieved; and meanwhile, the traditional fixed partition constraint is eliminated, and the risk of response lag and deceleration region falling caused by partition switching is avoided. On the basis of closed-loop control of motion intrinsic parameters, full-time-domain active safety protection is constructed while speed regulation precision is improved, and motion safety and self-adaptive experience are remarkably optimized.

The invention discloses a random step frequency radar high-resolution distance-Doppler spectrum estimation method. According to the method, a low-rank matrix filling algorithm based on a mixed truncation nuclear norm is utilized to recover time-frequency missing coherent information in a random step frequency echo signal; the method is helpful for suppressing high-fluctuation side lobes in the high-resolution distance-Doppler spectrum and improving the target detection and estimation performance of the random step frequency radar.

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 invention particularly relates to a small-step frequency stepping radar target extraction method, which comprises the following steps of: designing a frequency stepping interval so that the frequency stepping interval meets the condition that the ratio of the stepping interval to a sub-pulse bandwidth is less than 1 / 3; the ratio of the sub-pulse sampling rate to the stepping interval is an integer; based on the designed frequency stepping interval, the radar sequentially transmits frequency stepping signals, and a radar receiver samples stepping frequency echo signals; carrying out fast time dimension pulse compression on step frequency echoes sampled by a receiver to obtain point pulse compression data, and then carrying out slow time dimension point windowing IFFT to obtain an original coarse distance and fine distance plane; the method comprises the following steps: performing dechirp processing, clutter power spectrum estimation and extraction distance initial value estimation on an original coarse distance and fine distance plane, obtaining a new coarse distance and fine distance plane based on an extraction distance initial value, and finally rearranging a two-dimensional matrix into a one-dimensional matrix to obtain a final whole-course one-dimensional distance image. According to the method, rapid calculation can be achieved through FFT, and the method has the advantages of being small in calculation amount, clear in physical mechanism, small in one-dimensional range profile distortion and the like.

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.

The invention discloses a monitoring assessment device for auxiliary training, which belongs to the field of exercise training monitoring, and comprises a host which is used for collecting, counting and analyzing accessory data in real time, monitoring and recording stride frequency, and displaying information such as step height, step pitch and stride frequency fed back by each accessory; the first accessories are arranged on the two sides of the site and composed of a transmitting end A and a receiving end B, the step height and the step pitch are determined by transmitting ray signals through the transmitting end A and receiving signals through the receiving end B, and the multiple first accessories can be combined to form continuous monitoring; according to the invention, by arranging a multi-component cooperative structure of the host and the accessories 1 to 7, multi-dimensional action parameters such as stride frequency, step height, step pitch, arm swinging, head raising and head turning and the like can be monitored in real time at the same time. The first accessories are arranged on the two sides of the field and matched with accessories of body parts such as toe caps, heels, elbow joints, wrists and mandibular angles to form an all-around data acquisition network, and three-dimensional accurate analysis of training actions is achieved.

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 invention discloses a high-resolution imaging method for multi-band pulse sequence fusion of a step frequency ground penetrating radar. The method comprises the following steps: 1) acquiring echo data; the method comprises the steps of (1) carrying out adaptive sub-band fusion, (2) carrying out adaptive sub-band division, (3) carrying out sub-band sparse imaging, (4) carrying out adaptive sub-band fusion and (5) outputting a result, and can solve the problems that in the prior art, fixed weight fusion is not adaptive enough, and manual parameter selection is difficult.

The invention relates to the technical field of power control, in particular to a decentralized control method, device and program for a direct current controller. The pressure generated by users with different weights on the walking machine is different, and the power required by the direct current controller is influenced. In order to accurately determine the power value at the next moment, historical pressure time sequence data and the current power value of the user are obtained. Under the natural gait of the user, pressure data changes along with foot lifting and foot falling, so that a gait cycle data segment is obtained through periodical division according to the historical pressure data change trend. And then integrating pressure fluctuation and numerical value characteristics of all periodic data segments, determining a load characteristic value, and reflecting gait attributes of the user. Meanwhile, the stride frequency of the user also affects power output, so that the stride frequency coefficient is determined by integrating the length characteristics of the periodic data segment. And finally, adjusting the current power based on the load characteristic value and the stride frequency coefficient to obtain a power value at the next moment. The predictive adjustment enables the power control of the walking machine to be more intelligent, and the use safety and the operation stability are improved.

A method for target image reconstruction is provided. The method includes the steps of: transmitting step frequency waveforms having different constant frequencies at different time periods; modulating the step frequency waveforms into a frequency range each having a first frequency and a second frequency, wherein each step frequency waveform increases from the first frequency to the second frequency based on a range function, wherein the modulated step frequency waveforms are arranged with a certain sparsity factor. The method further includes: sending the modulated step frequency waveforms to a target and accepting reflections of the modulated step frequency waveforms reflected from the target; interfering the modulated step frequency waveforms with the reflections of the modulated step frequency waveforms to generate a beat signal of the interference between the modulated step frequency waveforms and the reflections of the modulated step frequency waveforms; and reconstructing an image of the target from the beat signal.