56 results about "Step frequency" patented technology

The invention discloses a method capable of realizing wide-range positioning of a cable fault, a spread spectrum step frequency wave signal is obtained by performing binary phase shift keying (BPSK) and pseudorandom sequence modulation on a step frequency signal, and the method can overcome the problem that the cable fault detection range of a spread spectrum time domain reflectometry (SSTDR) is limited by code element duration. A cable fault detection device is installed at the head end of a cable, a detection signal is injected from the head end of the cable, a high-speed ADC is used for signal collection, cable fault information is obtained, and wide-range detection of cable faults is achieved.

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 present invention discloses an intelligent human-machine interactive music treadmill control method, which relates to the field of treadmill control. The aim is to solve the problem in the prior art that the user frequently manually adjusts the speed of the running belt. The adopted technical solution is to collect the BPM value of the music, obtain the optimal SMF value and the current SMF value, and adjust the speed of the running belt of the treadmill so that the current SMF value is equal to the optimal SMF value. By obtaining the BPM value of the currently played music and the current step amplitude, combining the corresponding relationship between the BPM value and the SMF, as well as the relationship between the step amplitude, step frequency and the outer surface circumference of the belt drive roller and the motor speed, it is possible to adjust the motor speed to change the user's step frequency so that it corresponds to the BPM value. The present invention can automatically adjust the speed of the running belt according to the music, greatly improving the initiative and freedom of the user's movement and making it easier to obtain a free and relaxed movement as one wishes.

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.

The invention relates to a DSP-based step frequency sub-pulse phase difference simple calculation method, and belongs to the field of frequency spectrum synthesis. The method comprises the following steps: acquiring two adjacent step frequency sub-pulses received by a step frequency system radar; extracting a frequency overlapping part of the two sub-pulses; performing difference calculation and amplitude multiplication on phases of discrete points of the frequency overlapping part of the two sub-pulses to obtain an expression of a result sub-pulse of each discrete point; obtaining a mean value of a real part and an imaginary part of discrete points of the frequency overlapping part; and calculating the average value of discrete point phases of the frequency overlapping part, wherein the phase is the phase difference of the two sub-pulses. The step is simple and easy to execute, two steps of operation of firstly filling zero at a sub-pulse frequency coincidence position and converting from a frequency domain to a time domain are omitted, and calculation is directly carried out in the frequency domain; the occupied DSP memory is small, zero padding is not needed, and the program running time is short.

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.

An embodiment of the present application discloses a method for controlling a powered exoskeleton, including: determining the user's step frequency information based on the user's historical usage information; determining the lag duration according to the user's step frequency information; calculating a lag speed according to the lag duration, where the lag speed is the speed information of the powered exoskeleton corresponding to the moment after subtracting the lag duration from the current moment; determining a resistance torque according to the lag speed; and outputting the resistance torque, where the direction of the resistance torque is opposite to the user's movement direction. Controlling the powered exoskeleton based on this method can identify the user's movement lag time and use the lag time as a calculation factor affecting the resistance torque, so that the powered exoskeleton can make corresponding controls according to the real-time movement state of the person during the resistance training process, can realize resistance training under different speeds and different movement states, and improves the usage effect of the powered exoskeleton.

The invention relates to a step frequency radar signal processing method, a step frequency radar signal processing device and a computer readable storage medium. The signal processing method comprises the following steps: S1, sampling M points in the time width of each chirp signal, wherein the total number of sampling points is M * N; generating a two-dimensional array x (i, j); s2, carrying out distance dimension FFT (Fast Fourier Transform) on the two-dimensional array x (i, j); carrying out FFT (Fast Fourier Transform) of a speed dimension; s3, accumulating Mag values of the converted signals; s4, performing CFAR processing on the accumulated signal to obtain a peak target, wherein k targets are arranged; s5, calculating the phase difference of the signals at the position index k, and calculating the real Doppler of the target at the position index k; s6, calculating the real distance of the target at the position index k; and S7, calculating the real speed of the target at the position index k. The distance and the speed of the target can be effectively obtained.

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 discloses a variable mode decomposition method for step frequency continuous wave signal noise reduction, and belongs to the field of signal modulation. The problems that in existing frequency spectrum synthesis, the intensity of noise components is far higher than that of effective signals, and the noise components cannot be effectively suppressed are solved. The method comprises the following steps: acquiring 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 variational mode decomposition on each single-frequency signal to obtain a plurality of intrinsic mode functions; screening a mode of which the center frequency is consistent with the frequency of the effective signal as an effective signal mode, and taking other modes as noise modes; calculating a maximum information coefficient MIC between the effective signal mode and the noise mode; iterative optimization is carried out on parameters of variational mode decomposition based on a Bayesian optimization method until the MIC value of the effective signal mode and the noise mode is lower than a set threshold value; and reserving an effective signal mode, and reconstructing the step-frequency continuous wave signal after noise reduction. The method is applied to the field of high-resolution target imaging and distance measurement.

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.

The invention provides a cooling tower resonance detection method, which comprises the following steps of S1, arranging a vibration sensor at a preset position of a cooling tower, and collecting a first vibration data set of a cooling tower body; s2, a vibration meter is installed on a fan transmission system, a fan is started, and the operation frequency of a motor is adjusted in a stepping mode; s3, synchronously collecting a second vibration data set of the fan at the corresponding frequency at the adjusting point of each frequency, and recording the second vibration data set as a sequence [b, b,..., bn]; and S4, analyzing the sequence of the first vibration data set and the sequence of the second vibration data set through spectrum comparison, and identifying the characteristic frequency of the fan causing the resonance of the cooling tower from [b, b,..., bn] according to the vibration frequency coincidence degree and the waveform similarity. According to the invention, the resonant frequency is accurately locked by synchronously collecting the response of the tower body structure and the vibration data of the fan excitation source and adopting the stepping frequency scanning and multi-dimensional frequency spectrum comparative analysis technology.

The invention provides a preparation speed measuring method and device, wearable equipment and a storage medium. The speed setting measurement method provided by the embodiment of the invention comprises the following steps: acquiring measurement data of an IMU (Inertial Measurement Unit) under the condition that a user wears wearable equipment; determining the step number and the step frequency of the user according to the measurement data of the IMU; determining the stride of the user according to the height of the user, a pre-configured mapping relation between strides and stride frequencies under different heights and the stride frequencies; and determining the matching speed of the user according to the stride and the step number. According to the method disclosed by the embodiment of the invention, the speed setting measurement can be efficiently and quickly completed without complex operation and sensors such as a GPS (Global Positioning System), the method can be suitable for various scenes such as indoor, treadmills, mountaineering machines and outdoors, and meanwhile, the real-time requirement of a user on the speed setting measurement can be met.

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 invention relates to the technical field of audio signal processing, and particularly relates to a method for optimizing the phase continuity and transition section of a stepped frequency sweep signal; constructing a signal model to generate a stepped frequency sweep signal; optimizing the phase continuity; optimizing the transition section; synthesizing a signal, generating signals for each stepped section according to the optimized phase and transition section, inserting the optimized transition section signal between the signals for each stepped section, and splicing them to generate a complete stepped frequency sweep signal. By the above method, the effect of improving the overall quality of the audio signal and the measurement accuracy of the test system is obtained.

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 frequency sequence estimation method based on a FARIMA-LSTM model, and the method comprises the steps: collecting a frequency band signal in a target environment, carrying out the preprocessing of the frequency band signal, mapping the preprocessed frequency band signal to a (0, 1) interval, obtaining a frequency sequence, inputting training set data into a constructed FARIMA model, estimating model parameters, generating a residual sequence according to the model parameters, and carrying out the estimation of the frequency sequence through the residual sequence. And training the constructed LSTM model by using the residual sequence, combining the FARIMA model with the trained LSTM model, inputting test set data into the FARIMA-LSTM model for single-step prediction, evaluating model performance and adjusting parameters, generating a frequency sequence from a signal to be estimated, inputting the frequency sequence into the trained FARIMA-LSTM model for single-step or multi-step frequency sequence prediction, and finally, performing frequency sequence prediction on the signal to be estimated. And outputting a single-step or multi-step estimation result. Fractional difference processing is carried out on a frequency time sequence through an FARIMA model, interference of periodic components on trend prediction is eliminated, meanwhile, deep mining is carried out on randomness, burstiness and nonlinear dynamic characteristics in FARIMA residual errors through an LSTM network, and step-by-step estimation of the frequency sequence is achieved.

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 embodiment of the present application provides a method and related equipment for evaluating the user's motion state. The method includes: obtaining and processing the user's current motion data, determining the speed interval to which the user's motion speed belongs and the cadence interval to which the step frequency corresponding to the motion speed belongs; determining the high-frequency cadence interval, that is, determining the cadence interval with the largest distribution of cadence corresponding to the motion speed in the speed interval; determining the high-frequency cadence based on the high-frequency cadence interval; determining the user's cadence variation value based on the user's historical motion data and the high-frequency cadence; and determining the user's motion state based on the cadence variation value. This method can evaluate the user's motion state during the entire motion process, and divides the speed and cadence into intervals for evaluation, thereby avoiding the difficulty of comparison caused by excessive motion data and improving the accuracy of the evaluation.

The invention relates to a radar system and a method for estimating distance and speed using step frequency waveforms. A radar system and method is provided and includes transmitting a radar signal within a frame having N radar chirps, the N radar chirps having a step frequency waveform; receiving and sampling radar signals reflected from a target; a distance FFT process including a first domain fast Fourier transform (FFT) and a Doppler FFT process including a second domain FFT are performed on the received value to generate a distance FFT value and a Doppler FFT value. The distance and velocity of the target are estimated based on the distance FFT value and the Doppler FFT value, where the estimated distance r and the estimated velocity v of the target are calculated based on at least one equation comprising: (i) a first term corresponding to the target distance r0 measured by a first radar chirp of the N radar chirps, and (ii) a second term corresponding to the target distance r0 measured by a second radar chirp of the N radar chirps; and (ii) a second term corresponding to a center wavelength [lambda] N / 2 of a plurality of radar chirps of the frame.