269results about How to "Reduce the sampling frequency" patented technology

A communication system is presented. The system includes one or more transmitters configured to transmit a signal, where each of the signals generated by the one or more transmitters corresponds to a respective frequency. Further, the system includes a plurality of receiver front-ends configured to receive the signal transmitted by each of the one or more transmitters. The system also includes a plurality of remodulator modules configured to translate each of the received signals to a signal having a respective intermediate frequency. In addition, the system includes a combining module configured to combine each of the signals having respective intermediate frequencies to generate a single composite signal. Also, the system includes a single analog-to-digital converter configured to process the composite signal and generate a digital output. Additionally, the system includes a digital signal processor module configured to extract the signal transmitted by each of the one or more transmitters.

The invention discloses a method for dynamic acquisition and transmission of wireless data. In a data acquisition process of the method, the time interval for data acquisition is dynamically adjusted, according to the change threshold of data acquisition. In a data storing process, the time interval and opportunity for data storing is dynamically adjusted according to the change threshold of data acquisition. In a data sending process, the opportunity for data sending is dynamically adjusted according to the acquisition value alarming threshold and changing rate alarming threshold of data acquisition. Dynamically increasing or reducing data sampling frequency without increasing power consumption of wireless equipment is realized based on data abnormity degree. Alarm information is timely sent by determination of dynamic data acquisition abnormity, so that managers can maintain equipment as early as possible. Wireless data bulk sent is reduced, and the power consumption of wireless monitoring equipment is reduced. The process state information of entire detected equipment can be monitored without increasing the total transmission data bulk.

The invention relates to a vehicle-mounted road spectrum testing system based on surface structured light, comprising a camera, a projector, a vehicle body, data acquisition and processing equipment, an inertial navigation system, a GPS antenna and a clock triggering synchronization board. The system is characterized in that a plurality of three-dimensional point clouds capable of covering the whole road surface can be obtained by repeating the shooting process by a mobile projector and camera system, then coordinate conversion is carried out on the obtained three-dimensional point clouds in combination with the data acquired by the inertial navigation system, the data are converted to a uniform coordinate system, as the adjacent images overlap, denser and more reliable point cloud data can be obtained by correspondingly interpolating and filtering the redundant information; and the complete three-dimensional elevation data of the road surface to be tested can be obtained after splicing the point clouds obtained by scanning a plurality of images. The system provides a perfect scheme for road surface testing and can reduce the acquisition frequency while restoring the road surface elevation more veritably and lower hardware cost.

The invention relates to a method for real-time estimation of the queuing length of a signalized intersection based on a vehicle track. The method comprises the following steps: (1) judging a vehicle traffic state according to real-time vehicle traffic information; (2) estimating a vehicle queue-joining key point and a vehicle queue-leaving key point according to the real-time vehicle track information, vehicle traffic state and kinematical equation; (3) identifying an upstream reached fleet according to the estimated vehicle queue-joining key point; (4) performing queuing wave and evanescent wave estimation according to the estimated vehicle queue-joining key point, the queue-leaving key point and the identified fleet; and (5) estimating the intersection signal parameter and the queuing length according to the estimated queuing wave and evanescent wave. Compared with the prior art, the method is adaptive to a data environment with low sampling frequency and low sampling rate, and has the advantages of strong robustness, high real-time performance, good accuracy and the like.

A pulse running time filling level sensor includes a sampling device for sampling an IF signal at discrete instants and for converting the sampling values into digital sampling values, and a digital signal processing device for subsequent processing of the digital sampling values by calculating at least one new value characterizing the IF curve from respectively exactly two digital sampling values.

This invention relates to a method for virtual bass synthesis. The low frequency signal is attained by applying a low pass filter to the original. In order to reduce the operations, process of down sampling the low frequency signal, moving the low frequency signal to a series of harmonics whose frequencies are integral times as large as the frequency of low frequency signals, and then up sampling them are provided. By means of psycho-acoustic theory, the weights of harmonics are attained and applied to the harmonics. Finally the weighted harmonics are combined to produce the bass signal. As the result, the virtual bass effect which is almost the same as the low frequency of the original audio signal can be accomplished. Because the harmonic signals are high frequency ones, the virtual effect can be made in the panel speakers or ordinary low-end speakers.

The invention discloses a non-contact type gesture recognition system and method based on a continuous-wave micro-Doppler radar.A transmitting chain comprises a baseband signal generation module, a transmitter and a transmitting antenna; a receiving chain comprises a signal collection and processing module, three receivers and receiving antennae connected with the receivers respectively, and the signal collection and processing module is connected with an upper computer and is in clock synchronization with the baseband signal generation module; patch antennas are used as the antennae which face the direction of a human hand in parallel, and the three receiving antennae are different in locating place and are not collinear; a transmitted signal is reflected by an object and then received by the receiving antennae, a motion trajectory of the whole human hand in a three-dimensional space is obtained through data resolving of different received and collected signals, and movements of fingers are obtained through characteristic matching recognition of the collected signals.According to the non-contact type gesture recognition system and method based on the continuous-wave micro-Doppler radar, locating, tracking and gesture recognition of the human hand in the three-dimensional space are achieved in a non-contact mode, the advantages of being high in anti-interference capacity, simple in architecture and low in cost are achieved, data processing is convenient, and computing resources are saved.

A digital ultrasound beam former for ultrasound imaging, that can be configured by a control processor to process the signals from ultrasound transducer arrays with variable number of elements at variable sampling frequencies, where the lowest sampling frequency allows for the highest number of array elements. The maximal number of array elements is reduced in the inverse proportion to the sampling frequency. The beam former can be operated both in a RF-sampling mode and a quadrature mode. Parallel coupling of transmit / receive circuits for each element allow adaption of the receive Noise Figure and transmit drive capabilities to variations in the electrical impedance of the array elements.

The invention discloses a fast and accurate positioning device and method for railway transit vehicles. The positioning device comprises a laser displacement sensor, a cord-pull-type displacement sensor, a railway vehicle travelling distance detecting unit and a synchronous collecting and data processing unit. The vehicular laser displacement sensor is used to detect the distance between a vehicle and railway, the cord-pull-type displacement sensor is used to detect yaw angle of the vehicle travelling along the direction of the railway, vehicle travelling distance is obtained by the aid of a wheel axle pulse sensor, and vehicle yaw angle data and railway feature data are obtained by using the vehicular data collecting and processing module for calculation. The obtained vehicle yaw angle data and the railway feature data are matched to roughly position the vehicle, position correction is performed on the obtained railway feature data according to the rough positioning result, and the corrected railway feature data is matched with historical railway feature data to realize high-precision absolute or relative positioning.

The invention discloses a switched reluctance motor direct instantaneous torque control method based on voltage vectors. The switched reluctance motor direct instantaneous torque control method is characterized in that sectors can be divided according to a torque characteristic curve of a switched reluctance motor, and a size of a hysteresis region can be determined in a self-adapted manner according to a torque pulsation coefficient and an expected torque; by considering a torque output capability of a conducted phase of a commutation region, real-time adjustment of a duty ratio of a voltage of every phase can be carried out according to an operation condition and a conduction rule, and the voltage vectors of the direct instantaneous torque control can be refined. The method provided by the invention is advantageous in that the realization costs are low, the sampling period can be expanded, the current pulsation and the torque pulsation can be reduced, the winding copper loss is low, and the practicability is strong.

A Method to maintain Synchronization Tracking in TDD Wireless Communication comprises steps as follows: a. Dividing a midamble into two parts, then detecting the first one and the second one of the midamble one by one; b: The auto-correlation property operation between the two parts mention above and the corresponding to local midamble, then two peaks are got; c. compare the two peaks amplitude; d. confirming to advance or retard local time base on the result of the compare. Compare to the normal method, the novel interlaced sampling method harm the SNR of channel estimation using midamble very slightly. By using this novel method, the sample frequency can be decreased to only one time of the chip rate of TD-SCDMA system while still maintaining the ability to track the downlink synchronization.

A feedback cancellation assembly for an electroacoustic communication apparatus may include a signal transmission path for generation and emission of an outgoing sound signal to an external environment through an electrodynamic loudspeaker and a signal reception path comprising a microphone for generation of a microphone input signal corresponding to sound received from the external environment. The signal reception path may generate a digital microphone signal. The outgoing sound signal may be acoustically coupled to the microphone. An electronic feedback cancellation path may be coupled between a tapping node and a summing node to produce a feedback cancellation signal to the summing node.

The invention discloses a flexible DC power distribution network fault range finding method employing a fault transient process, and belongs to the technical field of power distribution network system fault range finding methods. The invention aims at solving problems that various types of commonly used fault range finding methods based on parameter recognition in a high-voltage DC power transmission system and a fault range finding method in a conventional AC power distribution network are limited to a certain degree because the voltage level of a DC power distribution network is lower and the DC power distribution network is liable to be affected by the noise. The method takes a double-end flexible DC power distribution network based on VSC as the research basis, and comprises the steps: extracting transient discharge voltage data of a VSC DC side capacitor through analyzing the transient process of a DC side fault, listing capacitor discharge time domain differential equations comprising a fault position parameter and a transition resistor parameter, carrying out the solving of simultaneous equations, and quickly and accurately achieving the fault range finding of the double-end flexible DC power distribution network. The method is shorter in sampling data window; is high in positioning precision; and is low in sampling frequency.

The invention provides a digital predistortion device and method for a band-limited simplified nonlinear filter. The device comprises a digital predistorter and a predistortion model training module of a predistortion model based on band limited simplified nonlinear filtering; the digital predistorter performs digital predistortion processing on an input digital baseband signal; a power amplifier outputs an analog radio frequency signal, generates an output digital baseband signal after the analog radio frequency signal is subjected to power coupling by an attenuation coupler, quadrature demodulation by a wideband quadrature demodulator, low-pass filtering by a low-pass filter and analog-to-digital conversion of a low sampling frequency, and inputs the output digital baseband signal after the input digital baseband signal and the output digital baseband signal are synchronized into a predistorter training module; the predistorter training module uses the least square algorithm to perform parameter training and then obtains power amplifier model parameters based on a band limited simplified nonlinear filter function, and sends the power amplifier model parameters to the digital predistorter. The invention uses the band limited method on a nonlinear filter function model to reduce the sampling frequency of a digital predistortion analog-to-digital converter, thereby reducing the difficulty and cost of realizing digital predistortion.

The invention discloses an intelligent signal frequency-conversion collection method which supports various communication interfaces, constructs a communication protocol library and supports an automatic loading communication protocol to realize interaction with equipment. Each equipment can be configured with different collection frequencies, and a collection task can be automatically or manually triggered. The dynamic change of the collection frequencies is realized according to the condition of signal change, and the sampling frequency is lowered when data are not changed. When an alarm and a fault occur and the data exceed a set threshold or a change rate, the data are automatically collected at high frequency. Aiming at various communication protocols of MODBUS, CDT and the like and the modes of a nested protocol, a condition judgment protocol, a plurality of continuous messages and the like, automatic adaptation and collection is carried out. Classification processing is carried out on the collected data, real-time triggering collection and revelation is carried out on alarming information, intelligent analysis is carried out on monitoring data, and intelligent processing is carried out on the classified analysis and the like of different classes of signals of single equipment and the mixed signals of a plurality of equipment.

An amplitude component of a modulating signal generated by a modulating signal generating circuit is detected, band-divided by first and second frequency selecting circuits, and the amplitude component of a high-frequency band is down-converted by a first frequency conversion circuit. The amplitude component selected by the first frequency selecting circuit and the amplitude component selected by the first frequency conversion circuit are amplified by first and second operational amplifiers, and a signal amplified by the second operational amplifier is up-converted by a second frequency conversion circuit to be restored to the initial frequency band. Output amplitudes of the first operational amplifier and a second frequency converter are added up by an adder to be direct-current converted. The amplitudes after the direct-current conversion are band-divided by third and fourth frequency selecting circuits, respectively, feedback amounts thereof are adjusted, and then fed back to the first and second operational amplifiers.

Methods and systems for filtering an analog signal sampled at a very high frequency and outputting a digital signal that has a very low sampling frequency to drive a material metering machine. The high frequency digital input signal is input to a first decimation element, which filters out the noise in the signal introduced by an analog-to-digital (A / D) converter and reduces the sampling frequency of the digital signal to a lower sampling frequency of 1200 hertz. The reduced rate digital signal is input into a second decimation element that contains several decimation filters, which reject the 60 hertz line noise and its harmonics while simultaneously reducing the sampling frequency of the digital signal to 10 hertz. The output of the second decimation element is then passed to a bank of selectable filters with sub-hertz cutoff frequencies to remove the machine noise from the material metering machine.

This invention relates to a method for virtual bass synthesis. The low frequency signal is attained by applying a low pass filter to the original. In order to reduce the operations, process of down sampling the low frequency signal, moving the low frequency signal to a series of harmonics whose frequencies are integral times as large as the frequency of low frequency signals, and then up sampling them are provided. By means of psycho-acoustic theory, the weights of harmonics are attained and applied to the harmonics. Finally the weighted harmonics are combined to produce the bass signal. As the result, the virtual bass effect which is almost the same as the low frequency of the original audio signal can be accomplished. Because the harmonic signals are high frequency ones, the virtual effect can be made in the panel speakers or ordinary low-end speakers.

The present invention relates to a medical injection system comprising an injection device (100) and a dose capturing unit (20). The injection device (100) incorporates expelling means (101) for setting and expelling a set dose amount of a drug from a reservoir. The expelling means (101) further comprises mechanical energy storage unit adapted to drive the expelling movement and a movable dosing member (350). In one form the dose capturing unit (20) is configured for being releasably attached to the injection device (100). The dose capturing unit (20) comprises a dose sensor (20d) configured to capture data relating to the movement of the dosing member (350) during dose expelling. When the dose capturing unit (20) is attached to the injection device (100), the systems forms a speed limiting means (F, M) to limit the speed of the dosing member (350) during dose expelling so that a force that counteracts the force exerted by the mechanical energy storage unit is generated.

The invention discloses a laser radar coordinate conversion method based on a vehicle body coordinate system, and the method comprises the specific steps: converting an instant laser beam coordinate system into a laser scanning reference coordinate system; solving the coordinates of a laser foot point relative to the laser radar coordinate system according to an inclined angle between the instant laser beam coordinate system and the laser radar coordinate system and a laser flight distance; converting the laser scanning reference coordinate system into an inertia platform reference coordinate system; measuring an installation inclined angle between a laser radar and an inertia navigation platform, and the displacements; solving the coordinates of the laser foot point relative to the inertia platform reference coordinate system according to a rotation and translation formula; and converting the inertia platform reference coordinate system into a period start instant coordinate system. The method does not need to convert laser foot point data into the WGS-84 coordinate system, converts the data into a vehicle carrier instant coordinate system at a starting moment of scanning, reduces the operation quantity and data dependence, and also can maintain the relative coordinates of the point relative to a vehicle. The method does not depend on GPS data, and especially avoids interpolation or prediction errors caused by GPS failures.

A memory system and a control method for the same enable stable operation at high frequencies without a radiant noise problem. In the memory system, a plurality of DRAMs is provided on each of a plurality of modules, and each DRAM is connected with a memory controller by data lines and clock lines. The clock lines have a topology exclusively applied to each module, while the data lines have a topology for connecting them to their associated DRAMs on each module. Command / address lines also have a topology similar to that of the clock lines. In this case, data signals supplied through the data lines and clock and command / address signals supplied through the clock lines and the command / address lines are transferred at different timings between the DRAMs and the memory controller. For this reason, the DRAMs and the memory controller are provided with circuits for matching the timings.

The invention relates to a large dynamic signal demodulation device and method of an interferometric optical fiber sensor. The method is characterized in that after a phase modulator conducts step wave phase modulation on light emitted by a laser, a light pulse pair is generated through an intensity modulator and input into the interferometric optical fiber sensor of an unbalanced structure to form interference, photoelectric detection and analog-to-digital conversion are conducted on an interference light signal through a photoelectric converter, the interference light signal is input into a digital signal processor and then sequentially passes through a data pre-processing module, an orthogonal signal extraction module and an orthogonal signal demodulation module which are located in the digital signal processor, a signal demodulation algorithm is completed, measured phase information is obtained, and finally the information is output through a data output module. The large dynamic signal demodulation device and method of the interferometric optical fiber sensor have the advantages that each sampling point can obtain an effective phase signal output, the demodulation dynamic range is determined by the sampling rate directly, the demodulation dynamic range is widened greatly at the same sampling rate, and the large dynamic signal demodulation device and method are suitable for large dynamic interferometric optical fiber sensors.

The invention relates to a real-time vehicle trajectory data-based intersection flow estimation method. The method includes the following steps that: 1) a research period [0, T] is divided into a plurality of consecutive basic time intervals, and the basic time intervals are classified; 2) a vehicle departure time likelihood function is calculated according to vehicle departure time condition probabilities corresponding to different basic time interval types under a given arrival time condition on the basis of the classified basic time intervals, and a final likelihood function is calculated;and 3) the vehicle departure time likelihood function is solved, so that vehicle arrival rates in the basic time intervals can be obtained. Compared with the prior art, the method of the invention canadapt to low-sampling frequency and low-sampling rate data environments and does not need the fusion of historical data. The method has the advantages of high robustness, high real-time performance,high accuracy and the like.

The invention relates to a carbon dioxide concentration calibration modification device which comprises at least one calibration modification device, wherein the calibration modification device comprises a calibrated carbon dioxide concentration sensor, an MCU (Microprogrammed Control Unit), an OLED (Organic Light Emitting Diode) display screen for displaying calibration state information and real-time CO2 concentration values, indication lamps, start and calibration buttons, a ZigBee module as well as a server, a databank, a working computer, a sensor of carbon dioxide concentration to be calibrated, a ZigBee module with a hardware model same as that of the calibration device, a gathering terminal, a mobile phone APP and short messages. By exploring historical data, an optimal calibration mode and calibration time can be found, so that calibration operation can be relatively efficient. Meanwhile, calibration difficulties can be reduced, the measurement accuracy of the CO2 concentration sensor can be improved, reliable and accurate bases can be provided for monitoring of carbon dioxide concentration and fertilization of carbon dioxide in environments of greenhouses, and realistic bases are also provided for precise control on draft fans and air windows of pig houses and livestock rooms.

The invention discloses a low-power consumption and low-distortion signal generator based on a direct digital frequency synthetic technology, comprising a programmable logic device, a stage waveform signal generating circuit, a compensating sawtooth waveform signal generating circuit and an addition and subtraction arithmetic device. Based on the direct digital frequency synthetic technology, the programmable logic device respectively outputs a digital amplitude signal of a target waveform signal and a digital amplitude difference signal matched with the digital amplitude signal; then the two signals are synchronously output to the stage waveform signal generating circuit and the compensating sawtooth waveform signal generating circuit; a stage waveform voltage signal Vof and a sawtooth waveform compensating voltage signal Voc which are synchronous to each other on a time domain are output to the addition and subtraction arithmetic device; a sawtooth waveform is compensated through superposition to finally acquire a folding line waveform signal. Without increasing a sampling frequency, the low-power consumption and low-distortion signal generator can acquire signals with lower distortion to solve the conflict between the signal distortion and the sampling frequency in the prior art. The invention is suitable for the application fields where have higher requirements on signal distortion degrees, clock frequencies and power consumption and effectively suppresses stage waveform distortion inevitably brought in the application of direct digital frequency synthetic smooth waveform signals.

The invention discloses a monitoring data intelligent sampling method based on relevancy analysis, which includes the four key steps: time series data encoding, relevance relationship mining, state transition matrix calculation, and state prediction. According to the method, a monitoring cycle can be dynamically adjusted according to the prediction on future resource usage of a main unit, thereby reducing sampling frequency while resource usage varies stably, and increasing the sampling frequency while the resource usage varies sharply to save computing and storage resources. Compared with the prior art, the method has the advantages that the monitoring cycle can be enlarged and sampling frequency can be decreased while a machine runs stably; when the machine running fluctuates, it is required to decrease the monitoring cycle and increase sampling rate; more meaningful monitoring data are acquired, the quantity of gibberish to be collected is decreased effectively, spending major computing resources to on gibberish acquisition, computing and other processing is avoided, efficiency is improved, and high accuracy is maintained while gibberish collection is reduced.

The invention provides a human body parameter measurement system with variable sampling frequency. The system comprises a plurality of intelligent wristbands and a server, wherein the wristbands can be used for detecting body parameter information of a detected person in real time, and transmitting the measured body parameter information to the server at the same time; and the server is used for processing the body parameter information, and determining the sampling frequency of all body parameter information according to the frequency of heart rate. When the heart rate is normal, the sampling frequency is reduced, otherwise the sampling frequency is increased, so that comprehensive detection on body parameters of the detected person can be guaranteed, the data size can be reduced, the electricity consumption of the wristbands can be reduced, and the processing pressure of the server can be reduced.

The invention discloses a direct current power distribution network line single-pole ground fault locating method. The method comprises the steps that 1, a fault current differential initial value expression is obtained according to a transient characteristic equation of a fault current; 2, a fault current differential initial value is replaced through an interpolation algorithm; 3, a fault location value expression containing the fault current differential initial value is obtained; 4, the fault location value expression is combined with a loop current equation, and a fault-based location equation is obtained; 5, voltage and current value information before and after a single-pole ground fault happens is obtained, the fault current differential initial value obtained in the step 2 and the fault location equation obtained in the step 4 are combined, and a fault location value is obtained. According to the direct current power distribution network line single-pole ground fault locating method, calculation is easy, the application range is wide, the method is free of influence of factors such as transition resistance, the calculation result can be used for offline maintenance, automatic operation can be achieved, high resistance to transition resistance is achieved, and when the transition resistance is increased, the high location precision is still achieved.