573 results about "Function generator" patented technology

In one embodiment of the invention, a steering system for mobile medical equipment is disclosed including left and right steerable wheel assemblies including left and right steerable wheels, left and right parallelogram linkages coupled to the left and right steerable wheel assemblies, a steering function generator coupled to the left and right parallelogram linkages, and a steering tiller coupled to the steering function generator. The left and right parallelogram linkages transfer differing left and right wheel angles to the left and right steerable wheel assemblies respectively. The steering function generator generates the left wheel angle (LWA) of the left steerable wheel and the right wheel angle (RWA) of the right steerable wheel. The steering tiller receives an input steering angle to generate the left wheel angle and the right wheel angle to control the direction of the mobile medical equipment around flooring.

A communication system (20) comprises a transmitter (22) and a receiver (24). The transmitter (22) comprises a source of information symbols (30); a pulse shaping wave function generator (32); and a combiner (34) configured to express the information symbols received from the source as signals which are shaped in time and frequency domains by the wave function. The pulse shaping wave function generator (32) is configured to provide a wave function which has the Nyquist property and has a same shape as its own Fourier transform. The combiner (34) is configured to combine the wave function with a stream of digital data symbols to produce a filtered stream for transmission by the transmitter.

A signal processing system includes a jointly non-linear delta sigma modulator. In one embodiment, the jointly non-linear delta sigma modulator includes a non-linear quantization transfer function, and the output of the delta sigma modulator is defined, at least in part, by a non-linear interrelationship of multiple noise-shaping filter state variables. A look-ahead delta-sigma modulator can be implemented as a noise shaping filter and a function generator. State variables of the noise shaping filter provide the input data from which the function generator determines a quantizer output signal. Latter state variables are more dominant in determining the quantizer output signal. Accordingly, earlier state variables can be approximated to a greater degree than latter state variables without significant compromise in quantization accuracy.

The invention relates to pipeline defect ultrasound guided wave time reversal detection device and method. The method includes the following steps: selecting detecting frequency according to the detected pipeline corresponding free hollow column structure group velocity dispersion curve; inputting the frequency into the arbitrary function generator to generate center frequency used as single sound signal; sending the signal to each passage of exciting / receiving set to transducer unit; exciting longitudinal axis symmetry guided wave modal; sending the reflected signal to the computer and gaining reversal excitation signal by time reversal; repeatedly exciting guided signal to detect. The invention realize space and time focus for guided wave detection, greatly improve detection capability for little defect.

In an approach, hyperspectral and / or multispectral remote sensing images are automatically analyzed by a nitrogen analysis subsystem to estimate the value of nitrogen variables of crops or other plant life located within the images. For example, the nitrogen analysis subsystem may contain a data collector module, a function generator module, and a nitrogen estimator module. The data collector module prepares training data which is used by the function generator module to train a mapping function. The mapping function is then used by the nitrogen estimator module to estimate the values of nitrogen variables for a new remote sensing image that is not included in the training set. The values may then be reported and / or used to determine an optimal amount of fertilizer to add to a field of crops to promote plant growth.

The invention discloses an infrared lock-in heat wave non-destructive detection method based on image sequence processing, which is a new method for realizing infrared lock-in heat wave non-destructive detection by using computer software to process the sequence of infrared images. The method comprises the following implementation steps: using a focal plane infrared heat imager to collect the image sequence of heat wave signals, using a halogen light source modulated by sine law to excite, carrying out digital lock-in processing on heat wave signals and analysis of feature images. When the method is used for non-destructive detection, the focal plane infrared heat imager 5 is fixed on a tripod 16 and connected with a data acquisition card of a computer 11, and infrared lock-in processing software 12 based on the image sequence is used for finishing initialization and image display of the infrared heat imager. The halogen light source 6 is fixed on a special support 7 to ensure that incident light is irradiated in an area to be detected of a sample piece 2 as far as possible, a function generator 14 is connected with a light source power amplifier 13 through a signal wire 15, and light intensity of the halogen light source 6 is controlled to change by the sine law. The incident light of the halogen light source 6 is irradiated to the surface of the sample piece 2 to generate excited heat waves 4. The infrared lock-in processing software 12 based on the image sequence records reflected heat waves 3 or transmitted heat waves 1 generated on the surface of the sample piece 2, a lock-in processing module is used for extracting feature information of the heat wave signals and forming the feature images, an image processing and analyzing module processes and analyzes the heat wave feature images, and inner defect features of the sample piece 2 are extracted, so as to realize fast and accurate non-destructive detection of inner defects and damages of the sample piece 2.

A method for the non-linear ultrasonic online detection of early fatigue damage to a metal material belongs to the field of nondestructive detection. The method comprises the following steps: determining an excitation signal parameter according to the thickness of a tested piece and inputting the parameter to an arbitrary function generator to generate a sound signal; determining a threshold value of an acoustic emission instrument according to the amplitude of a no-load noise signal; performing fatigue loading on the tested piece, continuously detecting an acoustic emission signal in real time with an acoustic emission sensor, amplifying the acoustic emission signal, inputting the acoustic emission signal into the acoustic emission instrument, and judging ring with the acoustic emission instrument when the amplitude of the acoustic emission signal exceeds the preset the threshold value of the acoustic emission instrument; detecting a non-linear ultrasonic signal at equal time interval if the acoustic emission instrument does not display the ring or the times of the continuous ring is not more than an empirical value; and stopping detection if the displayed ring times is more than the empirical value, because fatigue cracks are generated and develop. On the basis of non-linear ultrasonic nondestructive detection, the method of the invention introduces acoustic emission technique, so the method does not make incorrect judgment when detecting the early fatigue damage to the metal material and realizes continuous online detection.

The invention discloses a quartz tuning fork strengthened photoacoustic spectroscopy gas sensor based on an acoustic resonator. The gas sensor comprises a laser (1), a focusing lens (5), a tubular resonator, a quartz tuning fork (11), a function generator (15) electrically connected with the laser (1) and a lock-in amplifier (14) electrically connected with the quartz tuning fork (11), wherein the focusing lens (5) and the tubular resonator are arranged on an optical path (2) of the laser (1); the function generator (15) is electrically connected with the lock-in amplifier (14); the tubular resonator is the acoustic resonator (9) with a slit (91) in the middle; the length of the acoustic resonator is not more than 10mm, the external diameter is not more than 1mm and the internal diameter is not more than 0.6mm; the width of the slit (91) is not more than 0.2mm and the length is not more than the internal diameter of the acoustic resonator (9); prongs (111) of the quartz tuning fork (11) are positioned on the slit (91) and the distances between the prongs (111) and the slit (91) are not less than 0.001mm. The gas sensor has simple structure, small volume and strong anti-jamming property, works stably, is convenient to adjust and use and can be extensively used for detecting the components or contents of the gases.

Logic design apparatus and method provides serial multiplexer chains in a programmable logic fabric, each element in the chain either selects output of block, or passes output from earlier element of the chain. Select line is a decoder structure or output from configurable function generator that is configured at power-on to create correct selection. Using such structure, larger multiplexer, including priority multiplexers, tristate buses or larger look-up tables (LUTs) can be created. These novel structures can implement priority, non-priority or tristate multiplexers.

The invention relates to a device and a method for detecting pipeline closed cracks based on the vibro-acoustic modulation technology and belongs to the pipeline nondestructive testing field. The device provided by the invention comprises a computer, a first function generator, a second function generator, a first power amplifier, a second power amplifier, a vibration exciter, an accelerometer, acharge amplifier, a first thickness concertina-type piezoelectric ceramic sheet array and a second thickness concertina-type piezoelectric ceramic sheet array, an anti-aliasing filter and a data collection card. The method provided by the invention comprises the following steps of: acquiring a pipeline first-order bending vibration inherent frequency by swept frequency excitation; taking the frequency as the one of low-frequency vibration in the vibro-acoustic modulation detection; simultaneously exciting low-frequency bending vibration and high-frequency supersonic waves into the pipeline, determining whether there exists closed cracks inside the pipeline by the existence of frequency components which equal high frequency supersonic wave frequency subtracts or adds low frequency bending vibration frequency in a received signal frequency spectrogram. The device provided by the invention is utilized to solve the problem that it is hard to detect closed cracks by traditional methods, and can be applied to detect closed cracks in industrial pipelines.

The present invention relates to the technical field of laser spectrum detection and gas detection, and in particular relates to a two quantum cascade laser spectrum-based multicomponent gas simultaneous detection device and method. An arbitrary waveform function generator outputs a periodic signal which only superposes high-frequency modulation signals in any half period to be used as a laser current signal, a room temperature continuous mode mid-infrared quantum cascade laser is driven by a current control unit, the laser emits a laser signal, the laser signal passes sequentially through a focusing collimating three-dimensional adjustment system, a first mirror, a sample absorption pool and a off-axis parabolic mirror to be reflected to a first detector, the first detector passes the laser signal through a data acquisition unit to convert into an electrical signal and transmit to a computer, and information of the gas to be measured can be obtained by analysis and processing of the electrical signal by the computer. The devices simultaneously utilizes two spectrums for gas detection, and has the advantages of high detection sensitivity, high detection accuracy, no need of external standard gas calibration, simple optical path adjustment, fast response, and stability, and the like.

The vertical dual-shaft four-cylinder electrohydraulic servo testing machine comprises: a hydraulic pressure drive for dual-direction stress filed, a four-cylinder drive fit to any loading path, a differential close-loop servo system, a function generator fit to different waves, a position transfer device fit to assemble the test piece, a guide plate and linear rail to ensure co-shaft and avoid bending. This invention is very convenient.

A direct digital synthesizer employs a trigonometric function generator utilizing decomposition of a larger angle into smaller sub-angles, interpolation of a desired sub-angle between two known angles and calculating the trigonometric function using complex arithmetic. The direct digital synthesizer has a phase accumulator to generate an angular increment signal of the output signal. A trigonometric function generator in communication with the phase accumulator receives the angle signal and from the angle signal creates the trigonometric function signal. An angle decomposing circuit is connected to receive the angle signal to separate the angle signal into sub-angles of the angular increment, a sum of the sub-angles equaling the angular increment. An interpolation circuit receives the smallest of the sub-angles to generate the trigonometric function for the smallest of the sub-angles by interpolating between the trigonometric function of two known angles. The direct digital synthesizer has a first angle trigonometric retaining for retaining the trigonometric functions of the known angles. At least one second angle trigonometric retaining circuit retains the trigonometric functions of for the remaining sub-angles. A complex arithmetic unit combines the interpolated trigonometric function and the second trigonometric function from each of the second angle trigonometric retaining circuits to create the trigonometric function.

The invention provides a system and a method for detecting CO gas based on a quartz tuning fork enhanced photoacoustic spectrometry technology, relates to a system and a method for detecting the CO gas and aims at solving the problem of low detection accuracy of the existing CO gas photoacoustic spectrometry detection technology. A data processing module transmits a current control signal to a laser device controller via a function generator, and meanwhile, transmits a temperature control parameter to the laser device controller; the laser device controller drives a laser device to emit near infrared laser which is incident into a gas chamber after being collimated and focused; the gas absorbs optical energy so that the optical energy is converted into heat energy and further converted into an acoustic pressure signal; a quartz tuning fork mounted in the gas chamber converts an acoustic signal into an electric signal; the electric signal of the quartz tuning fork is converted and amplified and then input into the measurement channel input end of a phase-locked amplifier; the phase-locked amplifier inverts the concentration of the CO gas to be detected by performing secondary harmonic detection in combination with the reference signal of the function generator. The system and the method for detecting the CO gas based on the quartz tuning fork enhanced photoacoustic spectrometry technology are applicable to CO gas detection.

A transfer function generator provides the ability to provide a non-linear response in a feedback loop to compensate for non-linearities introduced elsewhere in the system. The transfer function generator includes a non-linear function generator configured to provide an output current that is a non-linear function of an input signal representing an error to be corrected. The transfer function generator can also include a linear function generator configure to provide a linear output current as a function of an input current representing the error corrected. Tuning devices can be provided to adjust the turn-on level of the non-linear function generator and the output level of the linear function generator to allow the transfer function generator flexibility in implementation.

The present invention relates to processes, systems, and apparatuses for transcieral delivery of pharmaceutical formulations to the eye using ultrasound. In one embodiment, a transducer is placed in contact with a coupling media contained in a coupling well in contact with the sclera. When the transducer is placed at a desired standoff distance, ultrasonic waves are emitted to increase tissue porosity and transport a pharmaceutical formulation through the scleral tissue and into the eye. In another embodiment, a function generator is coupled to an amplifier, a matching network, and a transducer configured to maximize the cavitation effect of ultrasonic waves for drug delivery across a sclera.

A computer cursor control device includes (1) a light source generating light directed toward a stationary surface, (2) an optional phase modulator, (3) an optional function generator causing the phase modulator to periodically phase shift the light, and (4) a signal processor determining a direction in which the device is moving from a beat frequency or an asymmetry in the light intensity. Another computer cursor control device includes (1) an optical element combining reference and measurement beams to form a heterodyned beam, (2) a phase modulator located in an optical path of the reference beam or the measurement beam, (3) a function generator causing the phase modulator to phase shift the reference beam, and (4) a signal processor determining a direction in which the device is moving from a beat frequency of the heterodyned beam.

A small-sized, high-functionality optical pulse compressor capable of generating a low-power, high-repetition-frequency ultrashort pulse train used for ultralast optical communication and photometry, and a simple-structure optical function generator for realizing an arbitrary time waveform. The optical pulse compressor comprises and optical Fourier transform device (F) having an optical phase modulator (9) driven by the repetition-frequency of an input optical pulse train and a dispersive medium (8), for converting the shape of an input optical pulse frequency spectrum into its time waveform, and an optical filter (3) inserted ahead of the optical Fourier transform device (F), for reducing the spectrum width of an input optical pulse, wherein the optical Fourier transform device (F) converts a small-spectrum-width optical pulse output from the optical function generator generates an optical pulse. The optical function generator generates an optical pulse having an arbitrary time waveform by reproducing, as it is, a spectrum waveform-shaped arbitrarily by an optical filter on a time-axis by tch optical Fourier transform device (F).

The invention provides a monitoring method for blade crack of a wind driven generator. The monitoring method mainly includes setup of a piezoelectric ceramic fan crack damage health monitoring system and a fan blade crack damage assessment method. The piezoelectric ceramic fan crack damage health monitoring system mainly comprises piezoelectric ceramic pieces, a function generator and an oscilloscope. The working principle is an active surveillance technology based on a piezoelectric ceramic wave method, and the working procedures include utilizing the function generator to emit sine sweeping-frequency signals and the oscilloscope is used for real-time display and storage for received detection signals. The fan blade crack damage assessment method includes utilizing Fourier spectrum analysis to calculate two defined damage indexes based on wavelet packet analysis, successfully monitoring crack areas and performing verification through time reversal. The monitoring method is easy to operate, and the identification effect of blade crack of the wind driven generator is remarkable. The monitoring method is general, and can be applied to damage monitoring of composite materials similar to fan blades.

The invention discloses a planetary wheel numerical control polishing removal function generator, which comprises a revolution shaft system, a rotation shaft system, a polishing disk, an eccentric adjusting mechanism and a slewing mechanism. The revolution shaft system is connected above the eccentric adjusting mechanism; the slewing mechanism is connected to the bottom end of the eccentric adjusting mechanism; the rotation shaft system is connected below the slewing mechanism; the polishing disk is arranged at the lower end of the rotation shaft system; the rotation shaft system comprises a rotation shaft, a rotation motor, a rotation transmission mechanism and a rotation shaft base; the rotation shaft base is connected to the slewing mechanism; the rotation shaft is arranged in the rotation shaft base; the rotation motor is fixed to the rotation shaft base; and the output end of the rotation motor is connected with the rotation shaft through the rotation transmission mechanism. The planetary wheel numerical control polishing removal function generator has the advantages of high rigidity for the transmission of the rotation shaft system, balanced rotation and capability of acquiring stable removal functions.

An inductive coupled power transmission circuit has a rotating transformer, including an AC voltage supply for feeding an AC voltage via a series capacitor into the primary winding of said rotating transformer and a load being coupled to the secondary winding of said rotating transformer. The AC voltage supply includes a line rectifier for receiving AC voltage from a power line and generating a DC voltage. This is fed into a DC / DC converter for converting the DC voltage from the line rectifier into a controlled intermediate DC voltage. An AC generator generates an AC voltage from the intermediate DC voltage and feeds this via a matching transformer into the primary winding of the rotating transformer. A measuring circuit measures voltages and / or currents within the AC voltage supply and a function generator estimates voltage and / or current values at the load based on the measured values and controls the DC / DC converter and / or the AC generator based on the estimated values.

The present invention includes an apparatus and corresponding method for fluid flow control in microfluidic applications. A microchamber, filled with a fluid, is in fluid contact with a flexible plate. A transducer is acoustically coupled to the flexible plate. A function generator outputs a signal to excite the transducer, which in turn induces drumhead vibration of the flexible plate, creating a flow pattern within the fluid filled microchamber.

The invention disclosed a method for integrating CMOS circuit chips with carbon nanotubes (CNTs) into array-type sensors with signal processors enclosed. The method provides low-temperature and wafer-level fabrication processes including dripped a drop of dispersed CNTs solution on the top of CMOS chip, use micro probe card to contact with pairs of pads, with a function generator to generate dielectrophoresis (DEP) signal and with a lock-in amplifier to measure impedance value simultaneously. According to the impedance measurement it can detect the number of CNTs fixed on pair of pads. Only if the number of CNTs on the top of pair of pads were not expected, it would readjust the frequency of alternating current to the range of negative DEP force and repel CNTs from the top of pair of pads. Repeat positive DEP signal to attach CNTs until the number of CNTs as demand, then hold the DEP force until CNTs solution evaporated to make a well-contact between CNTs and pads. Furthermore, the surface of CNTs can be functionalized and let CNTs have high sensitivity to ambient molecules (Gas molecules, Bio molecules, et al.), then transfer the measured signal into signal processors of CMOS chips, the processors could be impedance measurement unit, current measurement unit, conductance measurement unit et. al., and it can measure, record and analyze the data of small varied signal directly.

In thermography apparatus, a lamp 102 is modulated sinusoidally and a camera 106 captures thermal images at the modulated frequency, but delayed by an adjustable preset delay. A signal delay box 107 is connected between a sinusoidal modulation signal function generator 104 and the camera 106. The delay box introduces a delay to the function generator signal so that the thermal image is captured after a period of time, resulting in an enhanced image.

The invention discloses a Fourier transform chip spectrometer based on integrated light technique, comprising an integrated optical waveguide chip having electro-optic modulation function. Light from a light source enters the integrated optical waveguide chip through a fiber transmission coupler, and waveguide light from the chip enters an optical waveguide interferometer through a sensitive window interval. The interferometer outputs signals to a photoelectric detector. A voltage function generator is used for applying voltages varying with time between two modulated electrodes of the optical waveguide interferometer, the photoelectric detector is used for real-time measuring the change of the signal strength of the interferometer varying with the modulated voltage, and a signal processing chip connected with the photoelectric detector and the voltage function generator at same time is used for rapidly processing Fourier transform on the signals of the interferometer to obtain an incident light spectrum. The Fourier transform chip spectrometer provided by the invention can determine visible-infrared light absorbing spectra of solids, liquid, even monomolecular adsorption layers in the sensitive window, and determine fluorescence spectra of fluorescent substances in the sensitive window, with the advantages of strong anti-interference capability, and is suitable for rapid on-site quantitative determination.

A spectral distribution error evaluation apparatus is used to evaluate precision of color matching between evaluation and target colors. A first weighting function generator generates a first weighting function on the basis of color matching functions, wavelength characteristics which are independent of a light source of the target color, and visual characteristics which depend on wavelengths. A second weighting function generator generates a second weighting function on the basis of light source information of selected light sources. A difference calculator calculates error values between the evaluation and target colors for respective frequencies. An evaluation value calculator applies the first and second weighting functions to the error values, and calculates the sum total of the error values as an evaluation value. In this way, a precision evaluation value which has high correlation with actual color appearance and is used to improve the color matching precision can be calculated independently of a change in condition such as a light source or the like.

The invention discloses a constant envelope multiplexing method of double-frequency four-component spread spectrum signals. The method comprises the following steps of: generating four signal components as corresponding baseband spread spectrum signals, and obtaining corresponding additional phase according to the value combination state of the baseband spread spectrum signals within the current period of time; generating a pair of components, of which the phases are orthogonal to each other, by the additional phase through a trigonometric function generator; generating two paths of carriers, which are orthogonal to each other, by a carrier generator, respectively multiplying the carriers by the generated components, and executing subtraction on the products to get a radio frequency signal meeting the constant envelope condition. The invention also provides a generation device of the constant envelope multiplexed signal, and a receiving method of the constant envelope multiplexed signal. According to the constant envelope multiplexing method, four signal components of two frequency points are synthesized into one constant envelope signal, so that low-range and medium-range receivers can process the signal with narrower receiving bandwidth and lower baseband so as to obtain the basic ranging performance, high-range receivers can get better ranging accuracy by wider receiving bandwidth and higher processing complexity, and the ranging performance of the receivers during receiving each signal component respectively is improved.