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 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.

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.

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 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.

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.

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 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.