107 results about "Digital algorithm" patented technology

Biometric systems capture and combine biometric information from more than one modality, employing digital processing algorithms to process and evaluate captured images having data for a biometric characteristic. Such digital algorithms may include a pupil segmentation algorithm for determining a pupil image in the captured image, an iris segmentation algorithm for determining an iris image in the captured image, an eyelid/eyelash segmentation algorithm for determining an eyelid/eyelash image in the captured image, and an algorithm for measuring the focus on the iris. Some embodiments employ an auto-capture process which employs such algorithms, in part, to evaluate captured images and obtain the best possible images for biometric identification.

A chaotic communication system employs transmitting and receiving chaotic oscillating circuits. One improvement to first-generation systems is the ability to modulate a nonreactive element in the transmitting circuit, thus increasing modulation bandwidth. Other features include insertion of a gain control amplifier in a chaotic receiver; signal filtering in chaotic transmitters and receivers; use of chaotic modulation techniques for cellular telephony applications; dual-transmitter and receiver systems; a dual receiver synchronization detector; interfaces to communication systems; analog chaotic signal modulation; use of multiple chaotic transmitters and receivers; digital algorithm improvement using a cube-law nonlinear component; a Gb-only receiver; a Gb-only transmitter; and positive slope transmitter and receiver systems.

The invention provides a novel method of transmit beamforming, which allows compact analog implementation of complex digital algorithms without compromising their features. It is aimed to support envelope shaping, apodization, and phase rotation per channel and per firing. Each of three embodiments represents a complete transmit channel driven by pulse-width modulated (PWM) waveforms stored in a conventional sequence memory. PWM signals controls the transmit pulse envelope (shape) by changing the duty cycle of the carrier. Beamformation data are loaded prior to a firing via serial interface. Under the direction of a controller, the circuitry allows high precision (beyond sampling rate) phase rotation of the carrier. It also provides transmit apodization (aperture weighting), which maintains an optimal trade-off among low sidelobe level and widening of the mainlobe. Implementing such an IC, the manufacturing cost of a high-end ultrasound system can be reduced. Equally, the proposed solution makes the benefits of digital transmit beamformers available to midrange and entry-level machines since it merely requires a modified programming of the sequence memory.

The invention discloses a frequency deviation self-adaptive precise compensation system and a frequency deviation self-adaptive precise compensation method in coherence optical communication, which relate to the field of the frequency deviation compensation in the coherence optical communication. The method comprises the following steps of adopting a tunable light source as a local oscillator receiving light source, outputting local oscillator light with a designated wavelength, utilizing the local oscillator light to conduct coherence reception and low-pass filter with a transmission signal, conducting digital sampling on the filtered signal, and solving the energy of the sampled signal by utilizing a numerical algorithm; recording an energy value corresponding to the wavelength, completing one-time scanning, simultaneously changing the wavelength value and repeating the previous steps to obtain a wavelength-energy scanning curve, and determining an initial wavelength of the transmission signal according to a position of an extreme value point on the curve; and dynamically adjusting the local oscillator wavelength value by self-adaptively detecting the energy value under the condition of the initial wavelength, so that the frequency difference value is minimized. According to the system and the method, the precise compensation of a frequency deviation value in the coherence reception is completed through wavelength scanning of the light source, determination of the extreme value and the self-adaptive tracking process, so that the performance of the entire coherence receiving system is improved.

The invention provides a stack type image sensor. The stack type image sensor is formed by an upper silicon chip and a lower silicon chip via the stack technology, wherein the upper silicon chip is a photosensitive sensor array, the lower silicon chip is a readout circuit and output interface, the upper silicon chip and the lower silicon chip are connected via a binding wire, the lower silicon chip of the stack type image sensor is the readout circuit and output interface, and a readout circuit and output interface of the whole stack type image sensor comprises a digital-to-analog converter, analog-to-digital converters, an amplifier, a row/column controller, a digital algorithm, a high-speed data interface, and a band-gap reference included in the lower silicon chip. By employing the stack type image sensor, the high-readout circuit and the high-speed output circuit are transferred to the lower silicon chip of the stack type sensor so that the area of a non-pixel array area in the upper silicon chip is effectively reduced, the photosensitive filling rate of the single silicon chip can be increased, low noise and low power consumption of sensor chips are realized, and the filling factor of a photosensitive sensor pixel array is greatly increased.

The invention discloses a high-speed comparator direct-current offset digital auxiliary self-calibration system and a control method. The system is formed by a configurable comparator comprising a compensation current source array, a self-calibration digital algorithm module and a time sequence signal generating circuit. The self-calibration digital algorithm module can generate two sets of digital signals in a symbolic coding mode according to output digits of the configurable comparator to control the opening and closing state of the compensation current source array, and thus the direct current offset voltage of the comparator can be calibrated to be within the adjustable precision range. The pre-amplifier stage bandwidth in the comparator can be configured so that power consumption under different sampling rates can be optimized.

A reverse osmosis membrane separation device includes: a reverse osmosis membrane module; a flow rate detecting unit configured to detect a flow rate of permeate water to output a detected flow rate value corresponding to the flow rate; a pressure pump configured to be driven at a rotation speed corresponding to an input drive frequency and to feed supply water to the reverse osmosis membrane module; an inverter configured to output a drive frequency corresponding to an input current value signal to the pressure pump; and a control unit configured to calculate a drive frequency of the pressure pump by a velocity type digital PID algorithm, such that a detected flow rate value output from the flow rate detecting unit becomes a target flow rate value that is set in advance to output a current value signal corresponding to a calculation value of the drive frequency to the inverter.

The present invention provides parking curb detection devices and methods for alerting a motor vehicle driver when a predetermined distance from a parking curb has been reached to prevent vehicle damage. An audio and/or a visible signal device alerts the vehicle driver when the correct stopping point has been reached. The present invention utilizes a triangulation led infrared sensor, a control box with digital algorithm filtering, long wave length and bandpass optical filters, and also electronic filters to largely prevent false alerts during bright sunshine conditions.

Techniques pertaining to enhancing acoustic effects of music playing through digital signal processing are disclosed. Genre, or style, of music embedded in a music file is received and identified in a digital signal processor (DSP). Based on the music genre, an equalization processing unit in the DSP processes the audio data stream in the music file through an equalization profile selected from a collection of sound equalization profiles preloaded in a memory unit. Each equalization profile contains digital algorithms specifically designed to boost or attenuate audio signals at certain frequency ranges in the audio frequency spectrum according to the characteristics of the style of the music. The equalization-processed audio data stream is then played in an audio playback system with an acoustic enhancement that closely reflects the nature and characteristics of the style of the music.

A digital method and system allowing crystal identification in radiation detector machines is described. The crystal identification is based on recognition of radiation detector signal shape through discrimination of detector signal's dynamic characteristics. The digital method is based on recursive and non-recursive algorithms, such as adaptive filtering combined or not with quantization methods. These digital algorithms, commonly used in other engineering applications, were modified and tailored for radiation detection. Although the method was specially designed for crystal identification measurement, which is exemplified here, it can effectively recognize the detector signal shape in any radiation detection context.

The invention discloses a method and a device for controlling a modular chopped mode plasma cutting power source. The method comprises the following steps of carrying out soft starting of open loop control on the output voltage of the power source, and then carrying out independent step closed loop control on the output current of a chopping module; and when the air gap breakdown and the arc striking are successful, enabling a digital controller to carry out the independent step closed loop control on the output current of the chopping module, and selecting different chopping modules to carry out closed loop control according to the instruction value iz of the total output current of the plasma cutting power source. The device comprises a total output instruction current setting module, a chopping module instruction current distribution module, a four-way digital PI (proportional-integral) algorithm module, a four-way PWM (pulse width modulation) signal module and a four-way current signal sampling module which are arranged in the digital controller. The method and the device have the advantages that the open loop control on the output voltage and the independent closed loop control on the output current are adopted, and the output voltage does not need to be detected in real time, so the control is simple; the frequent switching between a voltage loop and a current loop is not needed, the arc striking is easily successful, the reliability is high, and the service life is prolonged.

DC offsets in high-gain amplifiers should be corrected to avoid the signal distortion that would result from amplifier saturation. A predominantly digital technique is described in which a digital algorithm observes patterns in the sign of the amplifier output and drives a digital-to-analog converter (DAC), which reduces the amplifier's offset.

The invention discloses a programmable universal capacitance type liquid level sensing controller and a control method thereof, and relates to the technical field of sensor control.The controller comprises an excitation circuit of a sensor, a detection circuit, an analog-digital conversion module and a microprocessor module.The controller has the advantages that by means of programmable control, the sensor can meet various measurement conditions to obtain a richer and more precise measurement result; calibration is support and a calibration value is automatically loaded, so user operation is more convenient and efficient; in an active shielding mode, the stray capacitance of a measurement circuit is eliminated, and measurement precision is improved; detection of liquid levels in a needle and a container is supported; by means of the differential integral digital algorithm, the stable detection result is obtained, and rich result output and display are supported; logic condition prejudgment in a microprocessor is made, output of four gears of digital levels can be supported, result indication can be achieved through four gears of LEDs, the measurement result can be displayed in the form of a graph through an upper computer, and good human-computer interaction is achieved; abundant communication interfaces exist, UART\RS485\CAN and other control interfaces are supported, and the upper computer can select any interface for connection control.

The invention discloses a dark current correction method for a CMOS image sensor, and the method comprises the following steps: S01, enabling the CMOS image sensor to be placed in an all-black environment, setting different exposure conditions, and obtaining a dark current pixel value of a corresponding image; taking one pixel point in the pixel array as a reference point, calculating the proportion of the rest pixel points in the pixel array relative to the dark current pixel value of the reference point, and marking the corresponding proportion in the image to form a dark current network; S02, performing coarse correction on pixel points in the effective pixel array by adopting AFB in an analog signal processing module; and S03, calculating a dark current correction value AFB' of each pixel point in the effective pixel array through a digital algorithm in the dark current network, and performing accurate correction on the pixel value of the effective pixel array by adopting the AFB 'in the digital signal processing module. According to the dark current correction method of the CMOS image sensor, the dark current correction precision is high, and the correction result better conforms to the actual application situation.

The invention discloses a fast synchronizing device based on blind separation iterative reconstruction and suitable for scattering communication; the device has advantages that troposphere scatteringcommunication has an anti-nuclear-explosion capability through a communication channel of the troposphere scattering communication and the scattering communication has strong anti-interference capability, high anti-interception capability and high anti-interception capability and accounts for an quite important location in an complex battlefield environment. In order to fully develop the communication performance of the scattering communication system under a fading channel and a extremely low signal-to-noise ratio, the method disclosed by the invention is mainly used for carrying out bit synchronization by adopting a blind separation iterative reconstruction bit synchronous interpolation device, and meanwhile, carrying out carrier synchronization by adopting a high-order transformation domain fast carrier recovery algorithm; the two algorithms are combined to enable the scattering communication system to be rapidly and reliably synchronized when the normalized signal-to-noise is -6dB.The device is mainly a digital algorithm, is realized by adopting an FPGA and is high in integration degree and high in universality.

The invention relates to a biologic impedance measurement system. The system comprises an analog front-end module, a digital algorithm implementation module and a data transmission control module, wherein the analog front-end module is used for converting a sinusoidal digital code or a second excitation voltage signal into an excitation current signal, loading the excitation current signal to a to-be-measured living body, and converting an analog voltage drop signal generated when the excitation current signal flows through the to-be-measured living body into a digital voltage drop signal; thedigital algorithm implementation module is used for generating the sinusoidal digital code or the second excitation voltage signal, and converting the digital voltage drop signal output by the analogfront-end module into the frequency and phase information corresponding to the digital voltage drop signal; the data transmission control module is used for transmitting the frequency and phase information, corresponding to the digital voltage drop signal, output by the digital algorithm implementation module to an upper computer. The biologic impedance measurement system in the embodiment can meet requirements for different measurement precisions, a user can select different measurement modes according to the actual measurement demands of the user, the most effective measurement result is obtained, moreover, the body compositions can be analyzed, and the human organ can be modeled.

The invention discloses a resonant sensor frequency characteristic test system and realization method based on multi-frequency scanning technology, and belongs to the field of a sensor. The test system mainly comprises eight parts: a main control chip 0, an upper computer 1, a control switch 2, a safety detection module 3, a D/A conversion module 4, a sensor to be tested 5, an interface circuit 6 and an A/D conversion module 7. Through the frequency characteristic test method based on multi-frequency scanning, test efficiency is greatly improved under the condition of ensuring test quality; and a hardware circuit of the test system is low in cost, and the system is simple and convenient to use; meanwhile, the system integrates the safety detection module, and can combine with other automatic equipment easily to realize automatic test, thereby further reducing production and research and development cost; and the test data is processed through a digital algorithm, so that the system is high in anti-interference capability, good in system reliability and low in low power consumption.