183results about How to "Waveform distortion is small" patented technology

The invention provides an electrocardiosignal preprocessing method based on morphological multiresolution decomposition, which comprises the following steps that (1) a linear structural element is applied to drifting of a correction baseline of a morphological filter; (2) a lifting method is applied to constructing of morphological multiresolution to decompose an electrocardiosignal to a second layer and a third layer; and (3) a component with less QRS (Quantum Resonance Spectrometer) complex wave distortion in signal components of the second layer and the third layer is selected as a preprocessed electrocardiosignal. According to the electrocardiosignal preprocessing method, the linear structural element is applied to drifting of the correction baseline, so that waveform distortion is reduced to a greater degree. A morphological multiresolution decomposition method is applied to filtering of high-frequency noise such as electromyography disturbance, the performance is superior to that of the preprocessing method of wavelet transform and morphological filtering, and the method is simple and easy to realize. The lifting method is adopted to construct multilayer morphological decomposition, because prediction and update operators which are suitable for the electrocardiosignal are selected, the denoising performance is further optimized, and the distortion of characteristic waves of the electrocardiosignal is reduced.

A magnetoresistive element includes a meandering X-axis array that is constituted by X-axis segments alternately connected, and a meandering Y-axis array that is constituted by Y-axis segments alternately connected. When rotated 90°, the Y-axis array has the same layout as the X-axis array. Such a structure cancels the electrical resistance change due to the AMR effect, thus reducing the waveform distortion of output voltage.

A transmission device includes a pulse modulated signal generator that generates a pulse-modulated signal by changing the width of a pulse or the density of a pulse according to the magnitude of the amplitude component of an input signal while discretely changing the pulse height according to the magnitude of the amplitude, a modulated-signal generator that generates a modulated signal by integrating the pulse-modulated signal and the phase component of the input signal, a power amplifier that includes at least as many amplifiers as the number of the discrete amplitude levels of the modulated signal, changes the number of amplifies that amplify the modulated signal on the basis of the value of the amplitude level of the modulated signal, combines outputs of the amplifiers, and outputs a combined output, and an output filter that eliminates a square-wave component from the output of the power amplifier.

Disclosed is a distributing cable partial discharge test method based on oscillatory wave test. The method includes that a cable partial discharge testing and locating system based on oscillatory wave test is established; by means of the testing system, a cable is charged through a method of voltage increasing to a preset value at a tested cable end, and damped oscillation voltage is generated at the tested cable end through resonance oscillation that occurs by an inductor and a tested cable capacitor in the system; when partial discharge occurs at a position of the tested cable in a distance from a testing end, pulses can spread in two directions along the cable, and the position where the partial discharge occurs can be determined according to time difference that two pulses such as incident wave and radioactive wave reach the testing end. According to the distributing cable partial discharge test method based on oscillatory wave test, oscillatory wave is applied to partial discharge test of the distributing cable, and voltage increasing is performed on the cable through sine oscillatory wave that is generated by resonance oscillation of fixed inductor and the cable. By means of the distributing cable partial discharge test method based on oscillatory wave test, insulating conditions of the cable can be timely known within short time by the system, and thereby, accidents of the cable can be effectively prevented.

The power supersonic transducer exciting circuit used in biomedicine engineering technology includes two signal generator circuits; gate circuit with first and second inputs connected to the outputs of the signal generator circuits, control end accepting the frequency selecting signal, the third input accepting signal from the protecting circuit and output connected to the input of the driver circuit; driver circuit with output connected to the signal input of serially resonant power amplifier circuit; serially resonant power amplifier circuit with feeding input connected to the voltage output of multiple-stage DC source to output protecting signal to the protecting circuit and signal output connected to the power supersonic transducer to excite it to send supersonic wave. The present invention has simple circuit, easy regulation, controllable output signal amplitude and duty ratio, high transmission efficiency and circuit safety.

The invention provides a wavelet decomposition binary denoising method for the ultrahigh-frequency signal waveform of the partial discharge. The method comprises the steps of 1) arranging a partial-discharge ultrahigh-frequency sensor on to-be-detected power equipment, and acquiring the ultrahigh-frequency signal of the partial discharge by detection equipment; 2) according to a selected mother wavelet and a decomposition level, conducting the multi-scale wavelet decomposition treatment on the signals of the partial discharge to obtain a wavelet coefficient and a signal waveform at each scale; 3) in order to reduce the signal waveform distortion of the partial discharge, processing the coefficient of the wavelet decomposition, calculating the mathematical morphological gradient of the cumulative energy function of signals at each scale, calculating the steepness of the mathematical morphological gradient, comparing the steepness with a preset threshold, deeming the signals at the above scale contain a partial discharge signal and keeping the wavelet coefficient at the above scale to be constant on the condition that the steepness is larger than the preset threshold; or deeming the signals at the above scale only contain noise signals and resetting the wavelet coefficient at the above scale to be zero on the condition that the steepness is not larger than the preset threshold; 4) reconstructing the wavelet according to the processed wavelet coefficient to obtain the denoised ultrahigh-frequency signal of the local discharge.

The invention discloses a sinusoidal gas micro-pressure generator. The generator is characterized by comprising a U-shaped tube, wherein an excitation coil is sleeved outside the bottom tube of the U-shaped tube; an upper permanent magnet is arranged above the excitation coil, while a lower permanent magnet is arranged under the excitation coil, and the excitation coil is connected with an alternating current power supply through a lead wire; and magnetic fluid is filled in the bottom tube of the U-shaped tube, and is full of the bottom tube diameter of the U-shaped tube under the action of the magnetic force of the permanent magnets. The generator has the advantages of low waveform deviation factor, simple structure and easy control.

The power generating and monitoring circuit for use in biomedicine engineering and technology consists of exciting signal generator, serial resonant power amplifier circuit, active low-pass filter, controllable DC power source, voltage detecting circuit and current detecting circuit connected together. It is connected with intelligent monitoring system, and the output of the serial resonant power amplifier circuit is connected to the melting electrodes as load. The present invention has simple circuit, convenient regulation, high work efficiency, flexible control, and high measuring and calculating precision of the output power and load impedance.

The invention discloses a method for controlling a vibration hydraulic cylinder of a crystallizer. The method is characterized in that a prediction controller provided with a corrector, an integrally improved PID (proportion integration differentiation) closed loop controller and a valve forward and reverse control method are adopted to calculate the set aperture of a servo valve SPSV, the set aperture of the servo valve at any moment t SPSV (t) is calculated by the following function: SPSV(t)=KPN*SPSV0(t); SPSV0(t)=SPSV1(t)+SPSV2(t); ER(t)=SP(t)-PV(t); and SP(t)=Aset*SP1(t)+Offset. The tracking characteristic of a hydraulic system is good, thus the crystallizer can completely move according to a preset track. The invention has the advantages of stability, reliability, high control accuracy, fast dynamic response and is easy to maintain. The error between the set amplitude and the actual amplitude is small, frequency tracking is stable, wave form distortion and mechanical shock are less.

The invention relates to a variable capacitor array which has excellent controllability on a capacitance value and has variable and high tunability. The variable capacitor array includes a first variable capacitor (C1) having a capacitance which is varied according to application of voltage; a first terminal (O1) connected to one side of the first variable capacitor; a second variable capacitor (C2) having a capacitance which is varied by application of voltage; a second terminal (O2) connected to one side of the second variable capacitor; and a third terminal (I) connected to both of the other side of the first variable capacitor and the other side of the second variable capacitor, wherein a state can be selected by switching between at least two selection states among three selection states of a first selection state that the first terminal (O1) and the third terminal (I) are selected, a second selection state that the second terminal (O2) and the third terminal (I) are selected, and a third selection state that the first selection state and the second selection state are selected simultaneously.

The invention provides a waveshaping method and device for monitoring data. The method comprises the following steps: the monitoring data is acquired; whether the amount of the motoring data is less than the convention amount in the preset cache time is judged; if the amount of the motoring data is less than the convention amount, the deletion amount between the amount of the motoring data and the convention amount is acquired; uniform interpolation processing is performed to the motoring data according to the deletion amount, and the interpolation data is formed; the wave shape is formed according to the interpolation data. According to the waveshaping method and device for the motoring data, deletion data positions are uniformly distributed in the whole wave shape, and the wave shape distortion influence brought by the deletion data is dispersed, so that the wave shape distortion is reduced, and the accuracy of the wave shape is improved.

An insulation ageing test device of frequency conversion high voltage pulse equipment is prepared as connecting output end of pulse generator to primary edge of high voltage boosting transformer with its secondary edge being connected to wire in insulation sleeve, applying 300H2 to lkH2, 1kH2 to 5kH2 , 5kH2 to 10k H2 and 10k H2 to 20k H2 as operation frequency of high voltage boosting transformer alternately, connecting said boosting transformer to output of pulse generator for outputting square wave to meet requirements of insulation ageing test.

A low-cost magnetic encoder that facilitates generating sinusoidal magnetic flux is provided. First and second permanent magnet arrays each include a plurality of permanent magnets arranged such that magnetic poles having the same polarity face each other, and magnetic yokes disposed on side surfaces of the plurality of permanent magnets. The permanent magnets and the magnetic yokes are arranged side by side at a predetermined pitch in the moving direction of a magnetic piece array. First and second magnetic detectors corresponding to the first and second permanent magnet arrays are disposed in a positional relationship allowing detection of leakage magnetic flux generated when the permanent magnet arrays and the magnetic piece array are displaced with respect to each other.

The invention relates to a pulse switch control device and a control method thereof. The pulse switch control device comprises an H-shaped bridge type transmitted pulse module consisting of a first switch unit, a second switch unit, a third switch unit and a fourth switch unit, and a control module, wherein one diagonal switch group consists of the first switch unit and the fourth switch unit, and the other diagonal switch group consists of the second switch unit and the third switch unit; one opposite switch group consists of the first switch unit and the third switch unit, and the other opposite switch group consists of the second switch unit and the fourth switch unit; the control module is connected with each switch unit respectively; when pulse is transmitted, the control module is used for controlling the switch units in one diagonal switch group to be switched on, and controlling the switch units in the other diagonal switch group to be switched off to form a pulse loop; and when the pulse transmission is stopped, the control module controls the switch units in one opposite switch group to be switched on and controls the switch units in the other opposite switch group to be switched off to form a discharging loop. Due to the formation of the discharging loop, trailing of pulse currents or voltages can be effectively eliminated, and the waveform distortion of the pulse currents or voltages is effectively reduced.

The invention relates to a control method of a photovoltaic LCL type grid-connected inverter. The control method is characterized by comprising the steps of: considering that a photovoltaic LCL type grid-connected inverter system has input uncertainty faults and actuator faults, establishing a fault mathematical model, and setting a fixed control distributive law; establishing a system state high-order sliding-mode observer and state estimation errors thereof according to the fault mathematical model, and adopting the high-order sliding-mode observer for realizing accurate estimation of system fault information; and constructing a continuous integral sliding-mode fault-tolerant controller mathematical model according to the fault mathematical model, the fixed control distributive law, the high-order sliding-mode observer and the state estimation errors thereof, wherein the continuous integral sliding-mode fault-tolerant controller mathematical model is used for processing the actuator faults directly. The control method is reasonable in design, can realize stable control under parameter uncertainty faults and actuator faults, and exhibits good tracking performance and fault tolerance. The control method provides a new idea for the design of a large-scale photovoltaic LCL type grid-connected inverter control system, and has a good engineering application prospect.