176 results about "Distortion factor" patented technology

The present invention relates to a photovoltaic three phase synchronization control method realizing maximum power tracking swiftly and stably, which belongs to the technical field photovoltaic power generating control. The method includes the steps as follows: judging the DeltaP/DeltaV value according to the power difference DeltaP between the current time k and the previous time and the voltage difference DeltaV; working out the Iref(k) when the photovoltaic array produces the maximum power; using the Iref(k) to adjust the uq* under the coordinates in vectorial synchronous rotation with the electric network voltage; acquiring six ways of space vectorial SVPWM impulse series according to the rotation angle degree Theta of the three phase electric network voltage, with the aim to control the inverter in order to ensure that the output current of the photovoltaic inverter has the same phase position as that of the mains voltage while ensuring the photovoltaic array is realizing the maximum power output tracking. The power factor is 1. The present invention also can adjust the Idref(k) according to local load requirements, therefore achieving adjustment to the power factor, with low synchronization current harmonic wave distortion factor.

An optical disc device of the present invention obtains a reproduction quality that is independent of a mark distortion by receiving a signal that is obtained from an A/D converter for digitizing a reproduction signal of an optical disc medium and an offset correction means for performing offset correction, accurately measuring a mark distortion factor in a mark pattern having a long recording width by means of a mark distortion factor measuring means, and selecting one of output signals from a PRML signal processing means and a level judge binarization means by means of a digital data demodulation selection means by utilizing the measured mark distortion factor as a judgement criterion, to be used as a demodulation binary signal.

The invention discloses a double-tube Buck-Boost type PFC (Power Factor Correction) converter based on one-cycle control, a bridge rectification circuit is then connected with a BOCBB type double-tube Buck-Boost converter; one path of output signal of a PI (proportion integral) adjuster is sent to a noninverting input end of a comparator, the other path of output signal is superposed with a sampling signal of input current and then is sent to a resettable integrator, an output end of the resettable integrator is connected with an inverting input end of the comparator, an output end of the comparator is connected with an RS (remote sensing) trigger, one end of the RS trigger is connected with a reset switch of the resettable integrator, and a Q-end output signal of the RS trigger simultaneously drives two switching tubes of the BOCBB type double-tube Buck-Boost converter after passing by a driving circuit. The converter disclosed by the invention not only can realize output voltage raising and reducing control, but also can improve a network side power factor, reduces the distortion factor of network entry current, has the advantages of simple structure, high system efficiency and the like and is convenient to control.

In the prior art in which permanent magnets are regularly arranged over the whole circumference of a rotor core, a satisfactory magnetic flux distribution is hard to obtain, and the cogging torque and the distortion factor of the induced electromotive force waveform are large, whereby characteristics of a rotating electric machine are poor. Also, because the permanent magnets are arranged over the whole circumference, a large number of permanent magnets are required and cost reduction is difficult. A permanent magnet rotating electric-machine of the invention comprises a stator provided with a plurality of windings, and a rotor in which magnets are disposed in slots formed in a rotor core along an outer circumference thereof, the rotor core being fixed on a rotary shaft rotating inside the stator, and in which one magnetic pole is constituted by each group of three or more of the magnets. A total angle occupied by the group of magnets constituting one magnetic pole is in the range of 150 to 165 degrees in terms of an electrical angle.

A method of calibrating a compass sensor in consideration of a magnetic environment is provided. The method includes (a) acquiring magnetic force data by rotating a compass sensor 360 degrees, the compass sensor including a biaxial magnetometer, (b) fitting the acquired magnetic force data to an ellipse function, (c) transforming the acquired magnetic force data and the ellipse function into a circle which is centered on an origin, and (d) calculating a distortion factor based on an inclination of a major axis of the ellipse function or the acquired magnetic force data to a horizontal axis, the distortion factor indicating the degree to which a magnetic field is distorted.

The invention discloses a no-filter D-class audio amplifier based on the chaos frequency spreading modulating technology, mainly comprising a chaos frequency spreading triangle-wave generator, a comparator and a full-bridge output-stage circuit, wherein the chaos frequency spreading triangle-wave generator is used for generating chaos frequency spreading triangle-wave signals. When an audio signal is sent, the comparator is used for comparing voltage values of the audio signal and the chaos frequency spreading triangle-wave signal to output a square wave signal with changeable dutyfactor. After the power of the square signal is amplified by the full-bridge output-stage circuit, the square signal is outputted to a loudspeaker and recovered to the audio signal above the loudspeaker. The invention has the following advantages that the electromagnetic interference of the output signal of the D-class amplifier is effectively inhibited under the condition of no filter, the integration is easy, the chip area is saved, and the linearity of the chaos frequency spreading triangle wave used as the PWM carrier wave is not influenced by the modulation signal (chaos sequence) is guaranteed, thus, the distortion factor of the output audio signal is not influenced.

The present invention discloses a compressing method of the data recorded by the electric power waveform. The compressing process includes the steps of: the collected data is performed by the integer small wave conversion based on the rising format and then all the data having been converted is coded in the Huffman method; the decompressing process includes the steps of: each pressing data that is read in bit is decoded in Huffman method, and then the data having been decoded is performed by the integer small wave contra-conversion. The present invention has the characteristics of a small amount of computing, a high compressing rate, a small distortion factor, a small occupied computer resources, etc. and the method can be realized in a flushbonding system. The compressibility and the distortion factor can be adjusted according to the demand and the flexibility of the using of the software is added. The present invention can also provide a threshold value to the detail information to realize the lossless compressing and the lossy compression. The electric power system waveform recording device in the present can realize a long-time and continuous recording waveform by combining the electric hardware technology under the situation of high sampling rate and big capability and the waveform can be transmitted far away through the communication interface reliably and quickly.

The invention belongs to the technical field of image processing, and provides a processing method and device based on a projected image. The method comprises the steps that a secondary imaged image of the projected image on a projection surface is obtained, wherein the projected image is formed by projecting a preset reference image on the projection surface, and reference identification points are preset in the reference image; secondary image identification points in the secondary imaged image are obtained; a distortion factor is obtained according to the change of the position parameters of the secondary image identification points in the secondary imaged image based on the position parameters of the reference identification points in the reference image; an image to be projected is corrected according to the distortion factor. Processed projected images are made to be reduced in distortion or even be free of distortion, and thus the environment adaptive capacity of image projecting equipment is improved.

A system for, and method of, noisy automatic speech recognition employing joint compensation of additive and convolutive distortions and a digital signal processor incorporating the system or the method. In one embodiment, the system includes: (1) an additive distortion factor estimator configured to estimate an additive distortion factor, (2) an acoustic model compensator coupled to the additive distortion factor estimator and configured to use estimates of a convolutive distortion factor and the additive distortion factor to compensate acoustic models and recognize a current utterance, (3) an utterance aligner coupled to the acoustic model compensator and configured to align the current utterance using recognition output and (4) a convolutive distortion factor estimator coupled to the utterance aligner and configured to estimate an updated convolutive distortion factor based on the current utterance using differential terms but disregarding log-spectral domain variance terms.

The invention discloses a large-size LCD (liquid crystal display) screen defect detecting method based on machine vision. An LCD screen is zoned, one camera is arranged in each zone and calibrated toacquire a distortion factor matrix, and a homography matrix is obtained; a pure color picture is displayed on the LCD screen, each camera shoots an LCD screen image in each corresponding zone, distortion correction is performed with the adoption of the distortion factor matrix, all LCD screen images are transformed in the same coordinate system according to the homography matrix and spliced to obtain a complete LCD screen image, the edges of the LCD screen are detected, a regional area of the LCD screen is extracted, and defect detection is performed after background texture inhibition and image intensification are performed. Defect detection of the large-size LCD screen can be effectively realized, and better universality is realized.

The invention relates to a novel cross-diamond searching method. Firstly, a crosslet mode is adopted for pre-search to find a minimum block-matching distortion (MBD) point, the MBD is taken as a center to construct a large cross searching mode to find the MBD; secondly, the MBD of the large cross mode is taken as the center to start the diamond search that a large diamond is searched first, a small diamond mode is adopted for search if the MBD is positioned at the center, and the found MBD point is the final block-matching distortion point; and if not, the large diamond search is continued. A cross-diamond also adopts the halfway stopping technique, and the speed for searching stationary blocks and half stationary blocks is improved obviously; and the modified partial distortion criterion greatly reduces the computational complexity without influencing the distortion factor. The laboratory result shows that the novel cross-diamond searching method respectively saves 41 percent and 16 percent of searching points compared with the diamond searching method and the cross-diamond searching method under the circumstances that the signal-to-noise ratio is less reduced or even is not reduced; compared with other prevalent block-matching motion estimation methods, the novel cross-diamond searching method has higher searching speed and less distortion degree.

The invention provides an amending method and an amending system directing at an unbalanced zero intermediate frequency feedback, and the amending method and the amending system are used for solving the problems of unobvious effect of the existing amending method and inexact I/Q signal. The method comprises the following steps: sampling a zero intermediate frequency feedback signal, wherein the zero intermediate frequency feedback signal comprises an I signal and a Q signal; respectively counting direct current leakage volumes of the I signal and the Q signal, and performing the direct current amending treatment on the I signal and the Q signal according to the direct current leakage volumes; counting an amplitude ratio of the I signal and the Q signal after the direct current amendment, and performing amplitude amending treatment on the I signal and the Q signal after performing the direct current amendment according to the amplitude ratio; counting a phase position difference between the I signal and the Q signal after amending the phase position, and performing phase position amending treatment on the I signal and the Q signal after performing the amplitude amendment according to the phase position difference; and performing digital distortion factor updating treatment on the I signal and the Q signal after performing the I signal and the Q signal to obtain the I signal and the Q signal to be sent. With the adoption of the amending method and the amending system, the obtained I signal and the Q signal to be sent are more exact.

A system for, and method of, noisy automatic speech recognition employing joint compensation of additive and convolutive distortions and a digital signal processor incorporating the system or the method. In one embodiment, the system includes: (1) an additive distortion factor estimator configured to estimate an additive distortion factor, (2) an acoustic model compensator coupled to the additive distortion factor estimator and configured to use estimates of a convolutive distortion factor and the additive distortion factor to compensate acoustic models and recognize a current utterance, (3) an utterance aligner coupled to the acoustic model compensator and configured to align the current utterance using recognition output and (4) a convolutive distortion factor estimator coupled to the utterance aligner and configured to estimate an updated convolutive distortion factor based on the current utterance using first-order differential terms but disregarding log-spectral domain variance terms.

The invention relates to an electric machine, particularly for a synchronous machine excited by a permanent magnet. The electric machine comprises a rotor arrangement (4) having buried permanent magnets (6) and a stator arrangement (2) having an inner recess (3) for rotationally movably receiving the rotor arrangement (4), the rotor arrangement (4) comprising a plurality of rotor segments (7), each having a pole shoe (10), the outer contour thereof corresponding to an arc contour having a contour radius, the contour radius being smaller than the radius of the rotor arrangement (4), thus forming a gap between two adjacent rotor segments (7), the at least one outer contour of one of the rotor segments (7) having an arc contour designed such that an air gap length ratio of the radial spacingbetween the inner recess (3) and the outer contour along a radial outer boundary of the corresponding rotor segment and the radial spacing between the inner recess and the outer contour along a radial center axis of the corresponding rotor segment (7) is optimized with regard to the distortion factor of the course of the flux density distribution of the pole shoe (10).

The invention discloses a full-power wind power converter used for an electrically excited synchronous generator and belongs to the technical field of wind power generation. The full-power wind power converter comprises a motor side converter, a network side converter and two DC (direct current) side filtering capacitors C1 and C2, wherein the AC (alternating current) input end of the motor side converter is electrically connected with the electrically excited synchronous generator, the DC output end of the motor side converter is electrically connected with the DC bus side of the network side converter through the DC side filtering capacitors, and the AC side of the network side converter is connected with an electric network; the full-power wind power converter also comprises a DC chopper circuit which is connected with the DC bus of the network side converter in parallel; and the motor side converter is a two-quadrant three-level Vienna rectifier, the network side converter is a voltage-type three-level converter which is composed of a power device adopting controllable switches and is of a diode middle point clamping-type topological structure, and the DC side filtering capacitors C1 and C2 are connected in series and then connected with the DC side of the motor side converter in parallel. The full-power wind power converter provided by the invention has the beneficial effects that the distortion factor of the output voltage is effectively reduced, the loss is reduced, the output wave shape quality is good, the cost is saved, the maintenance is convenient.

A particular implementation receives a bitstream and derives parameters from the bitstream. The parameters include quantization parameters, content unpredictability parameters, ratios of lost blocks, ratios of propagated blocks, error concealment distances, motion vectors, durations of freezing, and frame rates. Using these parameters, a compression distortion factor, a slicing distortion factor, and a freezing distortion factor are estimated respectively for distortions resulting from video compression, a slicing mode error concealment, and a freezing slicing mode error concealment. The distortion factors are then mapped to a composite video quality score. For applications with limited computational power, the estimation of distortion factors can be simplified. In particular, the compression distortion factor, the slicing distortion factor, and the freezing distortion factor can be predicted from quantization parameters, ratios of lost blocks, and durations of freezing, respectively.