463results about How to "High sampling frequency" patented technology

A system for measuring ground reaction force and analyzing the performance of an athlete in which force sensors are located in the athletes shoe and a three dimensional accelerometer is located adjacent the athletes centre of gravity and the signals from the accelerometer and the force sensors are recorded and used to derive the three orthogonal components of the ground reaction force (GRF). An artificial neural network is used to derive the three orthogonal components of GRIF

The invention discloses a high-speed signal acquisition, storage and playback device based on FPGA. The device is composed of a signal conditioning circuit, a high-speed A / D conversion circuit, an FPGA processing unit, an SDRAM, a NAND FLASH storage array, a USB 2.0 communication unit and upper computer software. In an acquisition mode, after being processed by the signal conditioning circuit, an analog signal is converted into a digital signal by the high-speed A / D conversion circuit, and the FPGA processing unit caches the digital signal, carries out lossless compression by using an LZW algorithm and then writes into the NAND FLASH storage array. In the signal playback mode, the FPGA reads data from the NAND FLASH, the USB 2.0 communication unit sends the data to the upper computer, and the upper computer software receives and analyzes the data.

The invention discloses a five-axis linkage machine tool rotation shaft geometric error continuous measurement method. The method comprises the steps that a laser displacement sensor is arranged on a spindle of a five-axis linkage machine tool; three non-collinear calibration balls are arranged on the work bench, and the homogeneous coordinate expression of each calibration ball is set; a swing axis A and a rotary axis C are used as calibration axes; the laser displacement sensor is used to measure the position deviation of the center of each calibration ball in X , Y and Z directions when the swing axis A and the rotary axis C in different corners; and according to the position deviation of the center of each calibration ball and the homogeneous coordinate expression of each calibration ball, geometric errors of the swing axis A and the rotary axis C are calculated. According to the invention, an oblique surface is used to establish the mapping relationship among the position deviation of a rigid body to be measured in X, Y and Z directions; translation in X, Y and Z dimensions is mapped to distance change in a single dimension; one-time chucking and continuous sampling are realized at the same time; and the method has the advantages of high measurement efficiency and high precision.

The invention belongs to the control field of electric power electron converters and relates to a model prediction control method for a three-level voltage-source-type converter. The model prediction control method for the three-level voltage-source-type converter comprises the following steps: step one, building models of relations between currents of the alternating current side of the three-level voltage-source-type converter and switch functions; step two, building models of relations between capacitance voltage offsets of the direct current side and switch functions; step three, obtaining current instruction values through outer voltage loops and obtaining a current instruction value of the next moment by calculating current instruction values of several moments before; step four, setting value functions of a model prediction control algorithm for the three-level voltage-source-type converter; step five, calculating on-off state subsets; step six, achieving real-time prediction control. The model prediction control method for the three-level voltage-source-type converter is simple in algorithm, easy to achieve and capable of being adopted in a higher-level converter, and has generality.

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 relates to a positioning device and a positioning method for a rail traffic vehicle. The positioning device comprises a laser displacement sensor, a rail vehicle traveling distance detection unit and a synchronous acquisition and data processing unit, wherein the laser displacement sensor and the rail vehicle traveling distance detection unit are respectively connected with the synchronous acquisition and data processing unit. In the method, the distance between the vehicle and a rail is detected by using an on-vehicle laser displacement sensor; the traveling distance of the vehicle is obtained by the output of a wheel shaft pulse sensor or two on-vehicle laser displacement sensors; and finally, rail characteristic data is acquired by using an on-vehicle data acquisition processing module. The acquired rail characteristic data is matched with the historical data of rail characteristics to realize high-precision absolute or relative positioning.

The invention provides an automobile remote diagnostic system and method, wherein the system comprises a vehicle terminal, a remote diagnostic center and a client. The vehicle terminal comprises a microprocessor for controlling acquisition, storage and transmission of automobile diagnosis original data; a collection module in connection with the microprocessor and collecting the automobile diagnosis original data; a 3G communication module in connection with the microprocessor, and remotely transmitting collected automobile diagnosis original data; and a storage module in connection with the microprocessor, and storing the collected automobile diagnosis original data. The remote diagnostic center is used for remotely receiving and managing the automobile diagnosis original data of a vehicle terminal. The client is used for accessing to the automobile diagnosis original data. A remote diagnosis monitoring system of the prior arts has low sampling frequency and less sampling signals, and data can not be returned to a server timely; the automobile remote diagnostic system and method of the invention solve the problems.

The invention provides an underground cable fault detection system and fault detection method thereof. The underground cable fault detection system comprises a cable fault ranging device, a cable pathdetection device, and a fault point detection device. The cable fault ranging device consists of a low-voltage pulse signal source, a high-voltage pulse signal source, and a high-speed receiving device to realize signal detection in a low-voltage pulse reflection method and a flashover method. The cable path detection device includes an alternating-current high-voltage signal source and an electromagnetic induction receiving device; the frequency and amplitude of the alternating-current high-voltage signal source are adjustable; the alternating-current high-voltage signal source excites a to-be-detected cable to generate an electromagnetic field; and the electromagnetic induction receiving device detects the electromagnetic field generated by the to-be-detected cable. The fault point detection device includes a high-voltage pulse signal source, a direct-current signal source, an alternating-current signal source, a step-voltage receiving device, an electromagnetic induction receivingdevice, and an acousto-magnetic synchronous receiving device. The underground cable fault detection system can be applied to detection of underground cable open-circuit, short-circuit, grounding, low-resistance, high-resistance flashover and high-resistance leakage faults to obtain an accurate fault point.

A differential protection system and a differential protection method for a flexible DC distribution network line are provided. An FPGA-based protection device sends a sample pulse to a data collector. To achieve synchronized sampling and data window synchronization, line dual-end protection devices are arranged as a reference end and a following end respectively. The following end firstly sends a synchronization request command including a number of a sample and a corresponding time of the sample. The reference end returns information including a sample number and a corresponding sample time of the reference end after receiving the command sent by the following end. After receiving a corresponding data message of the reference end, the following end calculates a communication transmission time delay and a deviation between the sample times of the two sides. Through compensation of the communication transmission time delay and a secondary interpolation sampling synchronization method, synchronized sampling of the following end and the reference end is achieved. Through calculating the differential current of two ends of a direct current line, the method determines whether differential current protection criteria are satisfied and achieves differential protection of the direct current line. The system and the method can ensure correct actions on internal faults and correct non-actions on external faults.

Provided are a subtitle synchronization device and a subtitle synchronization method based on speech recognition. The subtitle synchronization device comprises a speech recognition module, a dynamic sampling adjustment module, a subtitle semantic comparison module, a subtitle synchronization module and a subtitle display module. The speech recognition module is used for extracting speech in foreground voice from an audio stream, and sampling and recognizing the extracted speech to generate corresponding text information; the dynamic sampling adjustment module is used for evaluating the degree of semantic recognition of the generated text information, and controlling the speech recognition module to adjust the sampling frequency according to an evaluation result to obtain text information with high degree of semantic recognition; the subtitle semantic comparison module is used for carrying out semantic matching on the text information with high degree of semantic recognition and texts of additional subtitles in multiple languages of a broadcasted video; the subtitle synchronization module is used for adjusting time information of a subtitle file according to time information of the speech if the subtitle semantic comparison module finds out a sentence corresponding to the text information of the recognized speech in the subtitle file; and the subtitle display module is used for displaying subtitles according to the time information of the adjusted subtitle file.

The invention discloses a motion estimation method based on image features and three-dimensional information of a three-dimensional visual system. The method includes the first step of obtaining two-dimensional image information and space three-dimensional information corresponding to two-dimensional image pixels in real time on the basis of the three-dimensional visual system, the second step of controlling collection intervals between adjacent frames through the adoption of an adjacent frame sampling interval self-adaptive regulation method and automatically regulating the sampling intervals of the t+1 moment relative to the t moment according to the dot pair number of the effective matching image features between the frame at the t-1moment and the frame at the t moment, and the third step of synthesizing two-dimensional scene image features and three-dimensional point cloud information and carrying out three-dimensional motion estimation according to the matching point pair number of the current two-dimensional image features of the adjacent frames to obtain high-precision three-dimensional motion estimation. Through the method, on the basis of satisfying accuracy and reliability of the three-dimensional estimation, the calculated amount is effectively reduced, and the method has the advantages of being less in calculated amount, small in limitation to an application scene and the like.

A plurality of carriers are divided into two systems, one on a low-frequency side and the other on a high-frequency side, a transmitting unit that executes processing for transmitting a signal wirelessly is provided in each of the two systems, and output lines of transmit amplifiers of each of the transmitting units are directly coupled and input to an antenna. A feedback unit on the low-frequency side feeds a low-frequency carrier signal portion contained in the transmit signal back to a distortion compensating unit on the low-frequency side, and a feedback unit on the high-frequency side feeds a high-frequency carrier signal portion contained in the transmit signal back to a distortion compensating unit on the high-frequency side. The distortion compensating units compensate for distortion on the low- and high-frequency sides.

The invention belongs to the technical field of avionics and relate to a module and a method for acquiring and processing a vibration signal of the rotating component of a helicopter. The module comprises a sensor interface circuit, a programmable amplifier, an anti-aliasing filter, an A / D converting circuit, and a FPGA which are successively connected. The method comprises steps of using a vibration sensor to input the vibration signal into the sensor interface circuit in order to convert the vibration signal into a voltage signal, and passing the voltage signal through a high-pass filter in the sensor interface circuit in order to filter a DC component in the voltage signal. Compared with a CPU-controlled A / D converting manner, a FPGA-controlled A / D converting manner increases sampling frequency and sampling realtimeness. By using anti-aliasing filtering technology, the order and the cut-off frequency of the filter can be set flexibly; the stop band descending slope of the filter is increased; and a signal anti-interference capability is enhanced.

The invention provides a high-voltage direct current broadband domain corona current measurement system. The high-voltage direct current broadband domain corona current measurement system comprises a sampling resistance sensor, an extra-high voltage local measurement unit, an optical fiber transmission unit, a safe location measurement unit and an upper computer. The sampling resistance sensor samples the corona current signals of a high-voltage direct current, and converts the corona current signals to voltage signals. The extra-high voltage local measurement unit collects the voltage signals, and optical signals are obtained through photovoltaic conversion. The optical signals are transmitted to the safe location measurement unit through the optical fiber transmission unit. The safe location measurement unit converts the optical signals to the voltage signals. The upper computer processes, stores and displays the voltage signals. The high-voltage direct current broadband domain corona current measurement system has the advantages of being wide in measured frequency range, strong in capability of resisting electromagnetic interference and the like and can have a long-term and stable operation under the environment of extra-high voltage direct current and under the condition of all kinds of bad natural environment conditions, and provides effective technical means for further research of high voltage direct current corona characteristics.

The invention discloses a double-axis synchronous movement control device and method based on the feedback of a laser displacement sensor, and the device comprises a double-axis synchronous movement control device body, a displacement detection system, and a control module. The double-axis synchronous movement control device body comprises a first drive mechanism, a second drive mechanism, a first linear movement platform, a second linear movement platform, and an experiment table. The displacement detection system comprises a long-distance laser displacement sensor, a high-precision laser displacement sensor, a reflecting plate, a workbench, a first dividing plate, and a second dividing plate. The control module is connected with the first drive mechanism, the second drive mechanism, the long-distance laser displacement sensor and the high-precision laser displacement sensor. The device enables the movement range of the double-axis synchronous movement control to be enlarged, breaks the limits of a conventional fixed-type detection device, does not need to return to zero, achieves the synchronous movement stably, accurately and quickly, and can quickly recover the synchronization when interference appears and the movement is not synchronous.

The invention relates to a parameter acquisition method for a primary loop system of a pressurized water reactor. The model parameter acquisition method comprises the steps of combining the characteristic that the pressurized water reactor is complicated in model structure, provided with nonlinear links, long in stable transition time, great in number of model parameters and variables, mutual coupling and the like, recognizing model parameters by adopting submodules, and checking the parameters by adopting an overall model; selecting input and output variables of each module to perform testing; reducing influences imposed on a recognition effect by noise signals through preprocessing; initializing the variables based on a differential equation of each module and a program setting method, and enabling the model to be stable in initialization; recognizing parameters of each module based on a parameter perturbation theory and an intelligent optimization method; checking the parameters and the model under various conditions by combining the submodules and the overall module; and acquiring nuclear power unit system mathematic model parameters applicable to electric power system analysis. The modules are fine and clear in structure, the model parameters are definite in meaning, the variables required by recognition are easy to acquire, the parameter acquisition method is quick, efficient and accurate, and the practicability is high.

The invention provides a measuring method for micro-deformation of a geotechnical material, which relates to image edge recognition and pixel measuring techniques. The method is applied to measurement of micro-deformation of a geotechnical material for the first time. A measuring apparatus comprises a WDW-E50D universal tester, an image acquisition device and a microcomputer. The measuring method comprises two parts, namely, image acquisition and image processing, wherein image processing comprises system parameter calibration and deformation determination, and each of the two parts comprises image graying, image binaryzation, test piece edge recognition, pixel determination, information storage and chart drawing. According to the invention, image information of different resolution is rapidly processed in batches, synchronous direct measurement of transverse and vertical deformation of a geotechnical material test piece is carried out under the condition of uniaxial compression test, the WDW-E50D universal tester is cooperatively used for acquisition of data, and a program automatically acquires scattered points and drafts the complete stress-strain curve of the material; the test piece and deformation are not interfered in the whole test process, non-contact measurement is realized, and the method can be extensively applied to determination of deformation of the geotechnical material during uniaxial compression testing.

The invention discloses a correlated imaging device and a correlated imaging method based on an optical parametric process. The method comprises the steps as follows: modulating the spatial intensity of detection laser to make the laser of which the spatial intensity is distributed randomly be irradiated on a target object; enhancing or converting the frequency of a collected signal reflected or transmitted by the target through an optical parameter conversion module, and using a barrel detector to detect the signal to increase the detection sensitivity of weak signals; and carrying out correlated imaging of the laser signal after optical parameter conversion to obtain a target imaging result. By combining correlated imaging and optical parameter conversion, the advantages of high sensitivity, high resolution and frequency conversion are achieved, and both horizontal image information and vertical distance information of the target object can be provided.

The invention discloses a vehicle load dynamic weighing method for an orthotropic bridge deck steel box girder bridge, which relates to the field of bridge health monitoring. The method comprises the following steps of: mounting a fiber grating strain sensor at the bottom of a U-shaped rib of an internal top plate of an orthotropic bridge deck steel box girder; measuring longitudinal bridge strain of the U-shaped rib when a vehicle passes through the position of the sensor; converting the strain into an optical signal by the sensor; demodulating the optical signal by using a fiber grating demodulator; carrying out cross-correlation analysis on actually measured strains of measuring points on the same U-shaped rib in the steel box girder at different sections so as to determine vehicle speed of the vehicle; analyzing actually measured strain area vectors of measuring points on different U-shaped ribs in the steel box girder at the same section; and carrying out angle Cosine distance analysis by using a strain effect linear area vector of the U-shaped rib of the steel box girder so as to figure out transverse acting position and weight of each vehicle on a running lane. The vehicle load dynamic weighing method for the orthotropic bridge deck steel box girder bridge, disclosed by the invention, has the advantages of convenience for mounting, low manufacturing price, no need of interrupting transportation, no excavation or damage of the road surface and capability of achieving nondestructive and automatic dynamic weighing of the bridge vehicle load.

The invention provides a metro gauge detecting system and a detecting method thereof and belongs to the field of urban mass transit gauge detection. The metro gauge detecting system comprises a data processing analyzing system and an image collecting system 10, a vibration compensation system and a positioning system which are respectively connected with the data processing analyzing system. The accuracy and precision can be both increased by the measurement of the metro gauge detecting system in each section of road; the system error is reduced; the control on the system is excellent; the manpower resource and the material resource are simultaneously saved; the efficiency is increased; and the metro gauge detecting system is suitable for high-speed and real-time detection requirement.

Disclosed are a method and system for brain activity detection. The method is: performing multi-channel synchronous collections of brain electrical signals and cerebral cortex blood oxygen signals simultaneously, and ensuring synchronicity of the collected signals among channels, and collecting said brain electrical signals and said cerebral cortex blood oxygen signals of all locations at the same time. The system comprises: a functional near-infrared light source emission module (2) which employs the frequency division multiplexing technique, wherein the light source is modulated by carrier of different frequencies, said signal is accessed from the multi-functional joint collection helmet (1) through a transmission optical fiber to irradiate the scalp, and after being scattered and absorbed by the brain, the attenuated light signal is processed by the functional near-infrared detection module (3); the functional near-infrared detection module (3) is used for detecting weak optical signals of the scalp; the brain electricity detection module (4) is used for detecting weak electrical signals of the scalp; the central control unit (5) is used for synchronizing and fusing data flows, sending control commands to each functional module, and uploading data to the host computer (6). The method and system can control the interference to be the minimum and have good time scale consistency.

System and a method wherein a wearable device receives sensor data at a wearable device and compares a first value determined from the sensor data with a second value determined from the sensor data to determine a percentage change in the sensor data from the first sample to the second sample. The system and method may also change a sampling frequency of the sensor at the wearable device according to one or more settings that were set by a user of the wearable device. The system and method optimizes power consumption while optimally recording data sensed by one or more sensors at a wearable device.

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.

A satellite antenna kinetic control system comprises a system setting circuit, a main control unit, a drive and power circuit, a current sensing circuit, a angular position sensing circuit, a rotate speed sensing circuit and a actuator. The main control unit mainly includes a DSP chip and a FPGA chip. The utility model effectively improves the pointing accuracy and the dynamic tracking performance and decreases the cubic capacity and the power consumption of the control system, so as to provide the significant value for the application in the field of the satellite antenna pointing control system.

The invention provides a controllable high-speed multi-channel signal acquisition control circuit system. The system comprises an FPGA (field programmable gate array), wherein the FPGA is connected with an FOT (fiber optical transceiver) to realize communication with a host computer; the FPGA is connected with a DAC (digital-analog converter) chip to output analog signals for control or driving; the FPGA is connected with a plurality of AD (analog-digital) conversion chips to realize analog data conversion of multiple channels; the FPGA is connected with a reserved control port for an extending function. The controllable high-speed multi-channel signal acquisition control circuit system meets the work requirement for synchronous continuous sampling of a large quantity of analog signal channels, solves the problem of resource waste caused by repetitive design of a common high-speed multi-channel signal acquisition control circuit system, shortens the design time for a multi-channel signal acquisition circuit and is applicable to signal acquisition work on various occasions.

The present invention relates to a compression system and method for electrical power system periodic waveform synchronous sampling data, wherein the system comprises a synchronous sampling unit, a comparator, a synchronous frequency doubling unit, a time-mark generator, a data-processing unit and a encode unit; the method comprises the following steps: 1. convert periodic signal to square wave signal through the comparator; 2. generate synchronous sampling pulse through the synchronous frequency doubling unit and the synchronous sampling unit performs synchronous digifax conversion under synchronization of synchronous sampling pulse and inputs convertion result into the data-processing unit, meanwhile, the time-mark generator records start moment of each frequency current and input time mark into the data-processing unit; 3. preliminary treatment to information through the data-processing unit; 4. encode to form a compressed file through the encode unit. The present invention performs preliminary treatment to sampled data before encode, enhances compression ratio, realizes high sampling frequency, overcomes influence to non-integer-period sampling, and improves data consistency.

The invention discloses a large texture haptic representation system which can achieve the haptic representation for large textures with the space intervals at the centimeter level or higher levels. The large texture haptic representation system comprises an interaction panel, a finger positioning device, a mechanical transmission device, a piezoelectric ceramic matrix driving device, a two-way information feedback device and a PC with a 3D display. The finger position is detected in real time through the finger positioning device, the two-way information feedback device controls the piezoelectric ceramic matrix driving device to drive the friction-force-variable texture representation interaction panel to generate high-frequency vibration, and therefore the tiny texture roughness on the surfaces of large textures is represented; by controlling the transverse movement and rotation of the friction-force-variable texture representation interaction panel through the three-freedom-degree mechanical transmission device to extrude skin and muscles of fingers, the radian of large textures is represented. The large texture haptic display system has the advantages of being high in accuracy, bandwidth and sampling frequency and low in mechanical damping and dry friction force, and meets the requirements for stability, transparency, passivity, dissipativeness and the like.

The invention discloses a time-sharing two-path image acquiring device and a calibration method thereof. The time-sharing two-path image acquiring device comprises the components of: a lens, a dividing-to-two prism, a first image sensor, a controller and a second image sensor. The dividing-to-two prism is arranged in an output optical path of the lens and is used for dividing an incident light beam to two sub-light-beams with same light intensity. The first image sensor and the second image sensor are respectively arranged at output light paths of the two sub-light-beams. The controller is connected with the first image sensor and the second image sensor respectively for controlling the first image sensor and the second image sensor to successively perform time-sharing triggering exposure, thereby obtaining object images at different time and achieving an image acquiring frame rate which is twice of that of a single image sensor. The calibration method at least comprises geometric calibration and brightness calibration. The time-sharing two-path image acquiring device and the operating method can remarkably increase image acquiring efficiency and simultaneously ensure image acquiring accuracy. Furthermore the time-sharing two-path image acquiring device has advantages of simple structure and low cost.