196 results about "Phase jump" patented technology

The present invention provides a spread spectrum clock generator that is capable of preventing phase jumps and jitters and suppressing the occurrence of Electro Magnetic Interference components and that can easily be applied to large scale integrated circuits. The spread spectrum clock generator can be configured with a filter, quantizer, fractional divider, and other elements. Also, this clock generator circuitry can be configured by combination of a delta-sigma ΔΣ quantizer and factional divider so that sine wave modulation and random number modulation can be realized. Thereby, control with digital values can be performed. This clock generator prevents precipitous phase variations in the output high frequency clock and makes fine phase control possible. Consequently, EMI reduction by 20-30 dB can be expected.

The invention relates to an urban intersection traffic signal control method, relates to a multi-phase-jump and vehicle full-dynamic induction traffic control method, and aims to flexibly control traffic signals at intersections by using a traffic signal instrument so as to improve the traffic pass property of vehicles at the intersections and reduce the total delay time of vehicles. The method comprises the following steps: 1) setting an upstream vehicle detector and a parking line vehicle detector at each lane of a traffic intersection, and detecting dissipating vehicle and information of vehicles entering the intersection in real time; 2) according to the numbers of vehicles waiting in different lanes and vehicles running into the intersections, automatically transmitting passing signals to busy lanes by using a busy lane priority pass method through a traffic signal instrument control system so as to induce the vehicles in the lanes to pass prior; 3) by using a method that compatible lanes adopt one same phase and non-compatible lanes are subjected to phase-jump induction control, providing the priority pass right for lanes with a plenty of waiting vehicles or a lane into which a plenty of vehicles run. Due to the adoption of the method, a relatively good induction effect can be achieved at intersections with unsaturated traffic vehicles.

The invention provides a vibration monitoring system and a signal processing method based on LFMCW (Linear Frequency Modulation Continuous Wave) radar. The vibration monitoring system comprises a radar transceiver, a tuned signal generator, a data collection module, a signal processing module, and a display and analysis module. The signal processing method comprises the following steps: step one,capturing effective baseband beat signals within each frequency sweep period, and generating composite beat signals; step two, estimating the beat frequency; step three, carrying out phase estimationthrough an algorithm similar to maximum likelihood estimate; step four, carrying out phase jump correction on an estimated initial phase time sequence; and step five, extracting vibration displacementtime domain information. The LFMCW radar is utilized to conduct non-contact type vibration movement sensing, vibration displacement time domain information is extracted by accurately estimating the initial phase of the beat signals within each frequency sweep period, and vibration monitoring requirements for target objects in an extreme environment and from a medium or short distance are satisfied.

A modulation feature measurement and classification system for classifying a pulsed signal that includes a preprocessor, phase measurement system and modulation classifier. Preprocessor detects pulse starts and stops, measures pulse duration and converts the pulsed signal into digitized baseband in-phase/quadrature samples. Phase measurement system measures short chip counts, long chip counts, phase jump magnitudes, number of phase states, and polynomial coefficients for phase modulation of the pulsed signal. Modulation classifier determines modulation type based on the measurements using both rules-based and similarity-based classification methods.

The invention discloses a light-spectrum phase calibration system and a light-spectrum phase calibration method based on a cascade Mach-Zehnder interferometer. A first reference interference signal with optical path difference d1 close to maximum imaging depth of the system and a second reference interference signal with optical path difference d2 close to zero optical path are separated from a cascade MZI (Mach Zehnder Interferometer) interference spectrum signal through Fourier transform, filtering and inverse Fourier transform; the first reference interference signal is used for demarcating and calibrating a fractional part of a light spectrum phase jump at the maximum imaging depth part in real time during a wave-number sampling process; the second reference interference signal is used for determining 2pi integer multiples of the light spectrum phase jump at the maximum imaging depth part, wherein the phase jump caused by an initial wave-number jumping is in linear relation with the depth; and the practical phase jump at any depth can be calibrated by combining the two reference interference signals. According to the light-spectrum phase calibration system and the light-spectrum phase calibration method disclosed by the invention, not only is real-time linear calibration realized, but also calibration precision of the light-spectrum phase jump is ensured, so that a 2pi confusion problem of the light-spectrum phase jump calibration is solved, and the real-time high-flexibility phase detection and the reconstruction of phase images can be realized.

The invention relates to a satellite clock error real-time prediction method based on a phase jump. The satellite clock error real-time prediction method comprises steps of: acquiring an original satellite clock error data sequence, preprocessing the original satellite clock error data sequence, performing polynomial fitting on a processed satellite clock error phase sequence, removing a periodicterm of the phase sequence, and calculating fitting precision; and predicting a satellite clock error and ending the operations if the fitting precision is less than a threshold value, detecting a frequency abnormal values from back to front if the fitting precision is greater than the threshold value to obtain a plurality of pieces of front and back data, predicting a satellite clock error and ending the operations if no anomaly occurs in frequency and the data is stable, and predicting a satellite clock error and ending the operations by adopting clock error data after the jump if the frequency is abnormal and/or the jump exists in the data. The satellite clock error real-time prediction method fully considers the frequency stability and frequency drift features of an atomic clock, performs order selection on GPS, GLONASS, BDS and Galileo, is applied to real-time clock error prediction of a satellite-based augmentation system, is stable and reliable in clock error prediction, improves clock difference error precision in SSR correction information, and improves the precision of the terminal positioning service.

The invention belongs to technology for simultaneously measuring the directions of a plurality of wireless signal interference sources, which comprises the following steps of: setting sparse dictionaries, establishing interference source incoming wave azimuth column vectors, establishing an interference source detection data matrix, determining a direction bit matrix and determining the directions of the interference sources. In the technology, the sparse dictionaries are constructed at a set angular resolution interval in the range of 1 degree to 360 degrees according to the array manifold of a receiver array by utilizing phase jump times and the sparse characteristics of space distribution of the interference sources, and are taken as basic parameter sets in the determination of the directions of the plurality of interference sources; and each receiver simultaneously acquires the plurality of interference sources. Therefore, the technology has the characteristics of effectively solving the problem of performance reduction caused by phase jump, maximally reducing high requirements on consistency among channels of the receivers, greatly reducing difficulties in work of a system, and the like, and overcomes the defects of extremely high requirements on the consistency among the channels of the receivers, great influence of the phase jump on direction measurement accuracy, and the like in the prior art.

The invention relates to a novel software phaselock technique applicable to micro-grid master-slave control. In a master-slave control structure of a micro-grid, a micro-grid master control inverter tracks the phase of a power grid while in grid-connected operation; and when in isolated island operation, the micro-grid master control inverter needs to maintain the system frequency to be unchanged; to ensure that the phase and the frequency of a voltage do not change suddenly during the micro-grid mode switching process, the invention provides the novel software phaselock technique; when the connected grid is changed to the isolated island mode, the phase of the power grid is locked; and an output phase after the grid is disconnected transits from the power grid phase to the micro-grid phase gradually, and no phase jump happens; when the isolated island mode is changed to the connected grid, a phase difference of the power grid and the micro-grid is firstly calculated, and subsequently the PI modulation is carried out on the phase difference; the output is used as a frequency compensating signal to be overlapped with the frequency under the isolated island mode and to be used as frequency reference of an output voltage of the micro-grid main control inverter; and by changing the frequency, the phase of the micro-grid main control inverter is enabled to approach to the phase of the power grid slowly; and when the phase difference of the micro-grid main control inverter and the power grid is less than a set value (theta0), the grid connection operation is carried out.

The invention provides a multi-gear code rate adaptive demodulation system and method based on a neural network so as to solve the technical problems of high complexity of realization of an existing multi-gear code rate adaptive demodulation system and large computation amount of a demodulation method. In the demodulation system, an ADC sampling module samples an analog modulation signal; a code element feature point extraction module carries out detection on phase jump points of the sampled signal by utilizing a one-dimensional convolution neural network trained by a neural network construction module; a code rate estimation module estimates code rate of the sampled signal according to the detection result; a signal-to-noise ratio estimation module estimates signal-to-noise ratio of the sampled signal; a controller module selects low-pass filter coefficients and an interpolation structure of a demodulation module according to the code rate estimation result and the signal-to-noise ratio estimation result, and calculates sampling rate conversion ratio of the demodulation module; and finally, the demodulation module carries out demodulation on the sampled signal according to the selected low-pass filter coefficients and the interpolation structure as well as the calculated sampling rate conversion ratio.

A information modulating and demodulating method used on digital communication includes realizing modulation by utilizing binary information code element to directly vary abrupt phase of sine carrier wave, utilizing lock phase ring to realize demodulation, making modulated signal g0(t) corresponding to number zero be sine wave of N carrier wave period and making g1(t) corresponding to number one be in sine wave of N carrier wave period with frequency of fc, applying phase jump off angle theta and parameter tau as modulation index for varying signal bandwidth and transmission code rate as well as demodulation property.

The invention discloses an intersection signal control method based on exit residual capacity constraints. Adopted devices comprise multiple traffic flow detectors, a data transmission subsystem, a data processing and control module and lane signal lamps. Firstly, each traffic flow detector acquires queue information of each exit lane at the intersection in real time; then, the traffic flow detector transmits the acquired queue information to the data processing and control module via the data transmission subsystem; and finally, the data processing and control module carries out logic judgment on the received queue information, when queue overflow is about to happen in certain exit lane through judgment, the data processing and control module adopts strategies such as a shortened green lamp and phase jump to instantly give a control command to the data transmission subsystem to change the color of the lane signal lamp, a vehicle flow driving in the exit lane is interrupted, and thus, smooth running at the intersection is ensured. On one hand, happening of a queue overflow condition at the intersection exit can be eliminated through a signal control technology, and traffic jam at the intersection can be avoided; and on the other hand, the passing ability of the intersection in a congested area is improved, and the traffic jam evacuation time is shortened.

The invention provides an extended binary phase shift keying (EBPSK) modem and an implementation method thereof. In the method, a DAC (digital-to-analog converter) on a modulation end is saved by means of simplified expression of an EBPSK modulation waveform; and by adopting a special filtering mechanism that a digital impact filter can convert phase jump of a pulse signal into amplitude impact, an analog comparator is used to replace a high-precision ADC (analog-to-digital converter) at a demodulation end, thus greatly simplifying a hardware structure of the EBPSK modem, obviously lowering cost, volume and power consumption of an EBPSK receiver and effectively improving the operating frequency and the transmission code rate of the EBPSK. The invention is particularly applicable to a wireless sensor network with high requirements for cost and power consumption.

The invention provides a voltage dip testing method, comprising the steps of: a) sampling voltage on AC power at the moment t1 and t2, respectively obtaining u1 and u2, wherein normal supply voltage u of the AC power is equal to U sine(omega t + phi); b) obtaining changing amplitude delta U; c) judging whether delta U > |delta u|, if true, voltage dip happens, wherein delta u is the presupposed allowable voltage dip value. The invention also provides a voltage dip testing device. The invention accurately judges the voltage dip, and accurately computes phase jump angle of the voltage dip.

The invention aims to provide a remote underwater sound communication method and belongs to the technical field of underwater sound communication. The method is based on demodulation and decoding combined iterative detection of differential encoding. A transmitter resists multi-path interference by using spread spectrum communication, the problem of phase jump and loop cycle skipping is solved by using differential modulation quadrature differential phase shift keying with high frequency spectrum utilization rate, and the transmitter adopts demodulation and decoding combined iterative technology to eliminate inter-code interference. The method has the beneficial effects that 1) the error bit rate performance of a remote underwater sound communication system is improved by the demodulation and decoding combined iterative technology; 2) the technical requirement on a non-linear amplifier is reduced by differential modulation, and differential modulation has engineering feasibility; and 3) the multi-path interference of a remote underwater sound channel is overcome by spread spectrum communication.

A method is disclosed for tracking the phase of a received phase-modulated carrier carrying a sequence of symbols represented by phase jumps in a low signal-to-noise ratio environment. An input sequence of symbols stored in a delay line. The phase of a current symbol in a phase locked loop, and the phase error detected in the phase locked loop is updated to take into account phase error estimates of future symbols.

The invention discloses a design method for a pure medium electromagnetic lens based on a meta-surface. The method includes the following steps that firstly, according to medium materials of the lens and the wavelength of working electromagnetic waves, the relation between phase changes and medium thicknesses is obtained; secondly, according to requirements for the type and focal length of the lens (a convex lens or a concave lens or a reflecting mirror), needed distribution of phase jumps is worked out; thirdly, according to phase distribution requirements, the medium lens with the corresponding thickness is established in electromagnetic simulation software, is simulated and finely adjusted and then can be manufactured, wherein the phase distribution phi is obtained according to the requirement of the lens designed in the second step, distribution of the medium thicknesses is worked out, and modeling and simulating are conducted in the electromagnetic simulation software. The design method is simple and flexible; along with reduction of incidence wavelengths, the focal length of the lens will be increased; a lens set composed of the lens and a traditional lens can eliminate chromatic aberration.

The invention discloses an island detection method and device. According to the method, a real time voltage angle is obtained according to power grid three-phase voltage calculation, a synchronous voltage angle is further determined according to a phase-locked loop based on the real time voltage angle; under normal circumstances, the real time voltage angle is approximately equal to the synchronous voltage angle; when an island and phase jump of grid point voltage occur, the real time voltage angle also changes suddenly with the phenomenon to enable a phase jump value to exist between the real time voltage angle and the synchronous voltage angle; if the average value of the voltage phase jump value of the grid point is larger than a preset jump threshold value in one circulation period, then the occurrence of the island is determined. The island detection method and device are simple in control process and convenient to achieve; the island can be detected in the one circulation detection period after occurrence, and therefore the detection efficiency is high; disturbance quantity is not needed to be added into the output of an inverter, and the output electric energy quality of the inverter can not be influenced; determination is conducted according to the average value of the phase jump, all interference factors are excluded, and the detection precision is improved; detection dead zones are reduced.

A phase jump amplitude and timing controller is used in a fiber optic gyroscope for suppressing color noise. The phase jump amplitude and timing controller inserts a phase/voltage jump into the feedback signal of the loop closure electronics of the fiber optic gyroscope. This phase/voltage jump breaks the repeated pattern of the drive signal. The IOC time-dependent characteristics are totally eliminated by the randomized feedback signal because no repeated signal is applied to the IOC. The randomized amplitude is preferably within the full ±π phase such that the optical errors average to zero. A fixed frequency higher than the interested spectral region can shift the color noise to higher frequency. A randomized frequency can spread the color noise over full spectrum, and totally eliminate the RDS. In other words, the color noise caused by the nonlinearity of the driving circuit and IOC spreads out over a wide range of spectrum such that no distinct frequency peaks are apparent in the spectral domain.

The invention relates to a power system voltage sag level evaluation method with consideration of a phase jump. The method comprises: S1, a fault condition of Monte Carlo simulation is determined; S2, according to the fault condition determined at the S1, a sag amplitude and a phase jump angle are calculated based on a voltage sag voltage-dividing model; S3, a preliminary statistical table and subdivision statistical table for the sag amplitude and phase jump are formulated based on the calculation results obtained by the S2; and S4, the calculation results are processed and thus are expressed graphically with consideration of the amplitude and phase jump. According to the invention, uncertain factors of an impedance angle between the fault line impedance and the system impedance, a fault distance, a fault type, and a conversion effect on a sag type by a transformer are taken into consideration; multi-times short-circuit calculation is carried out based on a Monte Carlo simulation method and a sag amplitude and a phase jump of a concerned node are calculated; the statistical tables and statistic graphs that consider the sag amplitude and phase jump are introduced; and the results are expressed in graphs to realize direct observation and detailed comparison.

The invention discloses an atomic clock smooth switching system based on real-time tracking technology, and relates to the technical field of the time frequency generation and maintenance of a satellite-borne atomic clock. The atomic clock smooth switching system comprises a dual-mixing time difference circuit, a FPGA module, a frequency synthesizer circuit, an electronic switch and an analog phase-locked loop, wherein the FPGA module comprises a DDS module, a phase difference measurement module, an infinite pulse response digital filter module and a fault detection module; on the basis of the DDS module and the dual-mixing time difference circuit, an error signal is filtered and purified through the infinite pulse response digital filter to obtain a frequency control word of the DDS with fine-tuned frequency control; the equality of the tracking period and the measurement is guaranteed through a real-time tracking algorithm without measuring the frequency and the phase in time-sharing, and the frequency and phase jump indexes before and after the switching are ensured.

The invention discloses a measuring method for a phase of a dual-wavelength micro-nano structure. Two lasers with different wavelengths are used as light sources to respectively acquire phase wrapping pictures, a phase jump coefficient of a position (a pixel) is determined by utilizing a known fixation relationship of two wavelengths at the same position (the pixel), so as to reconstruct the phase of an object. Phase information at different positions (pixels) of the object is obtained independently and does not depend on a relationship among adjacent pixels, therefore, the measuring method can be applied to measuring the phase information of the isolated discontinuous object, so that a phenomenon of generating accumulative propagation of errors because of route dependence in an unwrapping algorithm can be effectively avoided; the measuring method can be applied to phase measurement of not only continuously smooth objects but also the isolated discontinuous object (being subjected to sudden change); and meanwhile, the method disclosed by the invention greatly expands a measuring range for effectively measuring the object subjected to sudden change. The measuring method disclosed by the invention is simple, large in a measuring range, high in precision, and real-time, efficient and fast in measurement.

The invention relates to the field of relay protection of power systems, and discloses a DC side fault positioning system and method of a multi-end flexible DC power distribution system. The system includes a data acquiring module, a fault positioning module, a DC side fault protection module, and a result output module. The method herein includes the following steps: when a DC side line fault occurs, starting the low voltage over-current protection of a converter station, and transmitting a converter station locking signal; then using the phase jump characteristic of a hyperbolic tangent function to position a fault; locking respective bridge arm sub-module, based on the determination of whether a fault current stops attenuation, removing the DC fault current; after the disconnection of the fault line, closing the switch on non-fault lines. According to the invention, the method can position faults by using the characteristics of phase jump of the function when fault points and reference points match, which addresses the failure of conventional methods to start the closing of the switch by determining whether the corresponding DC line is energized. The method can also fast disconnect the fault lines and ensures normal operation of the non-fault lines.

The invention provides a voltage sag sorting method considering phase jumps. The method includes the following steps that firstly, three-phase voltage amplitude values and phase angles are acquired through sag recording data, three-phase phasors shown in the specification are acquired, and a phasor graph is drawn; secondly, sag information is acquired through phase voltage conditions acquired in the first step, whether three-phase voltages sag or not is judged, and three-phase jump values are calculated through the acquired voltage phase angles; thirdly, according to the sag information acquired in the second step and the sorting method, a sorting result is acquired. When the method is applied to voltage sag sorting, the defect that phase jumps are neglected in an original voltage sag sorting method can be overcome, the real condition of a power system is satisfied, and evaluative criteria and restraint measures which are formulated for power equipment sensitive to the phase jumps have certain reference value.

The invention discloses an order non-destructive correction method for encoding structured light. The method comprises: a structured light three-dimensional measurement system formed by a projection system and a camera is constructed; a parcel phase of a normal grating sequence and parcel phases phi1 and phi2 obtained by changing a phase shift sequence are obtained by a phase shift method, jump positions D1 and D2 of the two groups of parcel phases are extracted respectively, and then a position P1 needing correction is determined by an intersection calculation method; an absolute phase valuephi(x, y) is obtained by an unpacking operation and the absolute phase value phi(x, y) is processed by using a phase comparison method to correct an order value at the phase jump point P1; and order noises that are not processed are searched by eight-neighborhood traverse and the order values of the order noises are corrected by using a neighborhood phase comparison method. Therefore, an order error problem existing in the encoding structured light is solved; and the order non-destructive correction method is applicable to the order noise correction link for static and dynamic testing.