112results about How to "Suppress high frequency noise" patented technology

A dust collection unit for a vacuum cleaner includes a first filtering chamber filtering relatively large foreign objects, a second filtering chamber filtering relatively small foreign objects when air exhausted from the first filtering chamber is introduced into the second filtering chamber, an exhaust member disposed above the filtering chambers to guide airflow, a storing chamber disposed under the filtering chambers to store the foreign objects filtered in the filtering chambers, a sealing member sealing bottoms of the filtering chambers, and a rectifying unit formed on an exhaust side of the second filtering chamber to rectify airflow, thereby reducing noise generated by the airflow.

A electrical connector structure includes ground terminals formed in two rows, which are fixed into two bases respectively, in which each of the ground terminals includes a contact portion, a soldering portion and a main body is connected to the contact portion and the soldering portion, and each main body is fixed into the bases, and each soldering portion extends out of the bases; and a ground member including two ground plates, in which the ground plates covering surfaces of the bases, respectively, and a surface of each ground plate has a plurality of contact arms protruding, the contact arms are electrically contacted to the ground terminals, respectively, in which two ends of each contact arm contact the ground plates, respectively.

The invention relates to a system for measuring a physical variable using a plurality of measuring sensors (20). Said system is characterized in that an inverting measuring signal amplifier (17; 17.1, 17.2) is connected downstream of every measuring sensor (20), one output of a sensor (20) each being connected to an inverting input of the measuring signal amplifier (17; 17.1, 17.2) connected downstream of the measuring sensor (20).

The invention provides a blasting vibration predicting method, which comprises the following steps of: firstly, determining a reference blasting hole and a plurality of vibration measuring points, and placing vibration meters on each vibration measuring point; blasting the reference blasting hole to obtain blasting vibration waveforms having different distance points; and finally, executing a blasting vibration waveform predicting process. In the prediction process, actual blasting vibration test data is obtained firstly, the blasting vibration waveforms and migration stacked delay time of each blast hole on a predicting target point are then calculated according to distance from the predicting target point to the each blast hole and the reference blasting hole, and the vibration waveform of the predicting target point can be obtained based on a vibration wave stacking principle. A blasting vibration predicting result which is obtained by adoption of the method really shows an influence of a topographic condition of a field on blasting vibration, and the integral vibration waveform of the predicting target point can be obtained; a predicted vibration velocity peak value of waveform particles is quite approximate to an actually-measured vibration velocity peak value, and a time difference between the predicted vibration velocity peak value and the actually-measured vibration velocity peak value is also quite small; and an analysis result is accurate and reliable, so that adjustment of a blasting scheme can be better guided.

A method for diagnostic imaging includes measuring undersampled data y with a diagnostic imaging apparatus; linearly transforming the undersampled data y to obtain an initial image estimate {tilde over (x)}; applying the initial image estimate {tilde over (x)} as input to a generator network to obtain an aliasing artifact-reduced image x̆ as output of the generator network, where the aliasing artifact-reduced image x̆ is a projection onto a manifold of realistic images of the initial image estimate {tilde over (x)}; and performing an acquisition signal model projection of the aliasing artifact-reduced x̆ onto a space of consistent images to obtain a reconstructed image {circumflex over (x)} having suppressed image artifacts.

The invention discloses a microseismic signal noise reduction filtering method based on a VMD and a wavelet packet and belongs to the signal processing technology field. In the invention, a mode of combining the VMD and the wavelet packet is adopted; adaptivity of a VMD decomposition method and characteristics of a high mathematical theory basis, high frequency noise suppression and the like in the algorithm are used; and the wavelet packet has the characteristics of carrying out multilevel division on a frequency band, further decomposing a high frequency portion which is not subdivided in multiresolution analysis, and adaptively selecting a frequency band according to a characteristic of an analyzed signal so that a time frequency resolution is increased. In the invention, based on a condition of maintaining randomness, non-stationary performance and a burst transient characteristic of a microseismic signal, the microseismic signal is filtered. The algorithm is simple and easy and an effect is ideal. Effective noise reduction filtering can be performed on a mine noisy microseismic signal. And a good technical value and an application prospect are possessed.

The invention discloses a five-phase inverter random SVPWM modulation method, and belongs to the technical field of multi-phase inverter drive control. In every sampling cycle, the sampling cycle is kept constant, a PWM pulse is delayed randomly, to achieve random change of a switch cycle, at the same time, two vector action time obtained through an NFV-SVPWM algorithm are randomly allocated, and double-random of switch frequency and zero vector action time is achieved. According to the five-phase random SVPWM modulation method, on the condition of not influencing low frequency-band harmonic performance, the amplitude of higher harmonic is drastically lowered, harmonic originally concentrated on the switch frequency and around the integral multiple switch frequency is dispersed into a wider frequency spectrum range, thus a more consecutive and even frequency spectrum is obtained, electromagnetic interference and high frequency noise are effectively inhibited, and the electromagnetic compatibility of the system is improved.

The invention discloses a target location extraction method applicable to through-the-wall radar imaging, belongs to the technical field of image processing, and particularly relates to through-the-wall radar imaging techniques. According to an image formed by a back wave of through-the-wall radar, firstly, high-frequency noisy points in the image are inhibited through a two-dimensional low pass filter, then, a plurality of detection thresholds with reasonable layouts are adopted, binaryzation detection is carried out on the target image, then, connected domains in the image after the detection are searched and used as possible target areas, the connected domains under the various thresholds are classified according to target subordinating relations, finally, occurrence numbers of the corresponding connected domains of various targets are arrayed, the corresponding connected domains with large numbers are selected, and statistical averages of all pixel unit locations in the connected domains are used as target location coordinates. According to the target location extraction method applicable to the through-the-wall radar imaging, accurate location coordinates of a plurality of targets comprising adjacent targets and dim targets can be steadily extracted in the target image with a low through-the-wall signal to clutter ratio and a low through-the-wall signal to noise ratio, and accurate target location based on the through-the-wall radar imaging is achieved.

The invention provides a noise suppressing device and a method thereof. The device is mainly composed of a cavity, a plurality of ducts, an electroacoustic sensor, a loudspeaker and a noise suppressing circuit; wherein, one duct is connected with the cavity so as to provide an external acoustic signal to enter the cavity; another duct is connected with the cavity so as to send the processed acoustic signal an ear canal; the electroacoustic sensor is used for receiving the acoustic wave signal which enters the cavity and converting thereof into an electronic signal and then sending thereof the noise suppressing circuit; the loudspeaker is used for receiving the electronic signal which is generated by the noise suppressing circuit and generating an opposite phase acoustic signal; the noise signal with high frequency can be suppressed by a low pass acoustic wave filter which is formed by the ducts and the cavity; the opposite phase acoustic wave signal has better noise suppressing effect to the noise with low frequency in the cavity; the invention achieves the object of noise resistance with full frequency by the effect synthesis of two noise suppressions.

The invention relates to a noise suppression method for superconducting transient electromagnetic application. The noise suppression method is characterized in that the EMD method and the environment magnetic field reference measurement method are combined, and comprises the steps that firstly, a TEM receiving system and an environment magnetic field reference measurement system are established, a TEM signal and an environment magnetic field signal are measured respectively, and high-frequency noise filtering treatment is carried out on the TEM signal and the environment magnetic field signal through an EMD module; then, low-frequency interference related to the environment reference part is removed from the received signals; finally, a needed TEM signal is obtained. By means of the method, both high-frequency noise and low-frequency noise can be effectively suppressed; furthermore, due to real-time signal processing carried by a DSP module, the effects of improving the signal processing speed and saving the memory space of a system can be easily achieved, the application of the system is greatly promoted, and the measurement accuracy of the system is effectively improved.

An interleaving striped capacitor substrate structure for pressing-type print circuit boards is disclosed. To meet the high-frequency, high-speed, and high-density requirements in modern electronic systems, the interleaving striped capacitor substrate structure uses several dielectric materials of different dielectric coefficients to make a dielectric layer. One dielectric layer can be stacked on another to form a multi-layered capacitor substrate so that a single capacitor substrate can provide the highest capacitance required for the decoupling capacitor to suppress high-frequency noise signals, and the lower dielectric coefficient substrate required for high-speed signal transmission. This simultaneously achieves the effects of reducing high-frequency transmission time and suppressing high-frequency noise.

The invention discloses a loop circuit compensating circuit used for a Buck converter, and belongs to the technical field of electronics. The loop circuit compensating circuit used for the Buck converter comprises a leading phase compensating circuit and a full-differential low-pass filter circuit. The leading phase compensating circuit generates a zero point and two high-frequency poles to provide leading phase compensating; the full-differential low-pass filter circuit provides a pole and high lower-frequency gain; the output voltage of the leading phase compensating circuit and the output voltage of the full-differential low-pass filter circuit are added in a linear mode to acquire a voltage signal required by III-type compensating; because the high lower-frequency gain and two lower-frequency zero points are acquired, the defects that lower-frequency gain is low and steady-state errors are large in leading phase compensating are overcome. According to the loop circuit compensating circuit used for the Buck converter, because full-differential input and output structures are adopted in the leading phase compensating circuit and the low-pass filter circuit respectively, power supply rejection ratio (PSRR) is increased, the crosstalk problem among DC-DC converters in all paths of a PMU can be effectively solved.

The invention discloses a circuit board for a low-noise mobile phone and a method for reducing noise of a mobile phone system. A differential wiring mode is taken as a wiring mode of an audio signal wire of an audio module of the circuit board; the wiring mode is strong in anti-jamming capability; magnetic beads are serially connected to an input end and an output end of the audio module; the magnetic beads are specially used for restraining high-frequency noise and peak interference on a signal wire and a power line, have a capability of absorbing a static pulse and are capable of excellently reducing related noise; the output end of the audio module is connected to a related capacitor; and the capacitor can be used for efficiently filtering noise and restraining coupling interference between the capacitor and the output end.

The invention relates to a design method for a linear active-disturbance-rejection controller based on a prediction tracking differentiator, and the method comprises the following steps: a, designingthe prediction tracking differentiator, and performing the filtering of an obtained state signal through the prediction tracking differentiator to obtain a filter value; b, obtaining an extension state of the system through an extension state observer based on the filter value; c, correcting a PD control law through the extension state to obtain the linear active-disturbance-rejection controller.The method provided by the invention can inhibit the impact on the closed-loop characteristics of a system from the noise pollution, can effectively inhibit the phase delay phenomenon caused by the filtering, solves a problem of noise pollution amplification caused by a high-gain observer, and improves the robustness of a controller. The method improves the robustness of the active-disturbance-rejection controller to the high-frequency noise, and has the engineering practicality.

A light amount detecting apparatus includes: a photoelectric converting element converting quantity of light inputted to current; a current/voltage converting device having a positive input terminal connected to a first terminal of the photoelectric converting element, a negative input terminal connected to a second terminal of the photoelectric converting element, a negative output terminal for reversing polarity of a current inputted to the positive input terminal and outputting it as a voltage, a positive output terminal for reversing polarity of a current inputted to the negative input terminal and outputting it as a voltage, a first negative feedback resistor connecting the positive and negative output terminals, and a second negative feedback resistor connected between the negative and positive output terminals, the current/voltage converting device setting the photoelectric converting element in zero bias and converting the converted current to the voltage; and an amplifying device for amplifying the converted voltage.

The invention provides an X-ray pulsar recognition method based on Hilbert transformation, belongs to the field of weak signal processing, and relates to a profile recognition method. The X-ray pulsarrecognition method solves the problem that during current recognition, a large amount of operating time and storage space are occupied, and meanwhile, the influence of high frequency noise can be effectively inhibited. The method comprises the steps of 1, conducting Hilbert transformation on a standard profile and an observation profile signal; 2, extracting instantaneous amplitude characteristics of a standard profile signal and a profile signal to be recognized and utilizing a characteristic vector of the standard profile to construct a characteristic database; 3, calculating the spatial distances of characteristic vectors of the observed profile signal and all characteristic vectors in the characteristic database respectively, wherein when the distance is the minimum, the corresponding pulsar sequence is a recognition result. Inhibiting properties of the high frequency noise by the Hilbert transformation are utilized, instantaneous amplitude characteristics are extracted to designa minimum distance classifier to complete high speed recognition of a pulsar signal, and the X-ray pulsar recognition method is applicable to quickly recognizing an X-ray pulsar.

The invention relates to a round window band-pass amplitude preservation filtering data processing method in geophysical exploration. The method comprises the following steps of: gridding gravity and magnetic data by an interpolation method; supplementing an edge by using low-accuracy gravity and magnetic data; performing fast Fourier transform; calculating a round band window filtering frequencyresponse function in a wave number domain, and compensating; performing the fast Fourier transform to acquire the gravity and magnetic data subjected to band-pass filtering; and processing the gravity and magnetic data which has the size of the original data and is subjected to the band-pass filtering by using a reverse edge. By the method, a filter is subjected to signal amplitude preservation in a pass band, signals are completely restrained in a stop band, and gravity and magnetic abnormal low-frequency backgrounds and high-frequency noise can be suppressed; and the method is particularly suitable for intermediate-frequency useful signals of a round window in the wave number domain.

The invention is suitable for the field of laser range finding, and provides an operation road surface detection system and method for an automatic guided vehicle. The system comprises a laser range finding sensor, a motor coder connected with the motor of the automatic guided vehicle, a motor driver and a main controller which are respectively connected with the motor of the automatic guided vehicle and the motor coder, and a communication module which is connected among the laser range finding sensor, the motor driver and the main controller. The laser range finding sensor is a laser range finding sensor of a diffuse reflection type, is fixed at the upper part of the body of the automatic guided vehicle, and transmits detection laser to an operation road surface of the automatic guided vehicle at a fixed frequency and a fixed inclined angle, wherein the detection laser comprises a plurality of laser beams which are located in the same plane and the adjacent laser beams form the same inclined angle. According to the invention, the laser range finding sensor of a diffuse reflection type is used for transmitting the plurality of laser beams which are located in the same plane to the road surface at the fixed frequency and fixed inclined angle, and can achieve the detection of the trench size and obstacle size of the operation road surface of the automatic guided vehicle, wherein the adjacent laser beams form the same inclined angle.

The invention discloses a high-speed fully-differential noise reduction device for CMOS optical receivers. The noise reduction device comprises a low-noise trans-impedance amplifier which is used for converting a current signal output by a photoelectric detector into a voltage signal and preliminarily amplifying the voltage signal and has low equivalent input noise current, a single-ended to differential circuit which is used for realizing conversion from single-ended to differential output, increasing the circuit bandwidth, amplifying the voltage signal, effectively reducing equivalent input noise current introduced by a back-end circuit and eliminating common-mode noise introduced by a power supply and the like, a two-stage three-order differential limiting amplifier which adopts a staggered active feedback and capacitance degeneration circuit and is used for amplifying the voltage signal to a voltage level needed for a digital processing unit, and an output buffer stage which is used for converting an output differential voltage signal into a single-ended output voltage signal. On the premise of keeping the overall gain and bandwidth of the circuit, the introduced noise is reduced, and the sensitivity of optical receivers is improved.

The invention discloses a four-channel high-speed synchronous FMC acquisition device, and relates to acquisition devices in the fields of measurement and control, communication and the like. Accordingto the technical scheme, an AD acquisition circuit converts a single-ended signal into a differential signal which can be received by an AD chip through a two-stage transformer by using four paths ofinput signals, and a clock shunt circuit outputs a sampling clock and a sampling synchronization signal required by an analog-to-digital converter AD through frequency multiplication and frequency division. Meanwhile, two groups of AD sampling clocks and AD sampling synchronization signals are respectively sent to corresponding AD chips, synchronization data is sent to an FMC connector, and a data processing clock is sent to a signal processing carrier plate; the FMC connector configures a value required for working of an AD chip register through a serial peripheral interface SPI, two groupsof synchronous signals of AD data transmission are respectively provided for corresponding AD, after the AD works normally, data of four output channels are sent to a carrier plate through an FMC connector plug, and synchronous sampling and transmission of four paths of intermediate frequency data are completed.