791results about How to "Achieve inhibition" patented technology

This invention relates to solar volt flexible switch reverser, which belongs to solar volt power generation technique field, which exerts direct voltage of the solar energy board into input capacitor two ends, wherein, input capacity end is connected to second induction end; other end of second induction is connected to integration electrode and first capacitor end; the first capacitor other end is connected to the encode end of third, second tubes and emission electrode of thirst control switch.

The invention relates to a moire detecting and suppression method and device. The method comprises the steps of (a) shooting a first image of an LED display screen through an image acquiring device, and analyzing the gray level distribution of the first image in a frequency domain; (b) determining a moire existential state of the first image according to the gray level distribution; (c) adjusting the parameters of the image acquiring device and/ or the LED display screen according to the moire existential state. According to the method, the image of the LED display screen is acquired and subjected to moire detection, and saturation analysis and imaging area analysis of the image are realized, so as to guide and adjust the parameters of the image acquiring device and the LED display screen to suppress moire generated by shooting of the image acquiring device, so that adverse influences of the moire on subsequent correction can be effectively prevented.

The invention discloses a space tracking filter-based sea clutter suppression and target detection method, which belongs to the technical field of sea clutter analysis of marine target radar detection and tracking. The method is implemented by the following steps: establishing a state equation and an observation equation by taking the radial non-coherent radar echo data as the input and the echo amplitude and the conversion slope of amplitude as a state vector; designing an optimal alpha-beta-gamma filter under a linear condition to track the low-frequency sea clutter and estimate the optimal parameter combination, and finally subtracting the obtained filter value from the original data to realize clutter suppression and target detection better. Due to the genetic algorithm, a maximum value with improved signal-to-clutter ratio and corresponding optimal parameter combination in which alpha is 0.999, beta is 0.992 and gamma is 0.721 can be obtained. Moreover, the target is easily obtained by using threshold detection.

An exhaust gas purification device of a diesel engine having a DPF (diesel particulate filter) for collecting particulate matters such as soot and unburned components from exhaust gas of the diesel engine calculates an oil dilution quantity as a quantity of fuel diluting engine oil from a regeneration time of the DPF and an operation state. The exhaust gas purification device alleviates an increase in the oil dilution quantity by using a regeneration device that causes the oil dilution quantity less than the oil dilution quantity caused by another regeneration device when the oil dilution quantity exceeds a predetermined value. Thus, both of suppression of the oil dilution quantity and inhibition of deterioration of fuel consumption due to post-injection can be achieved.

The invention discloses a half-cycle repetitive controller for a position servo system. Reference signals with half-cycle symmetry are set, a half-cycle feedback link is constructed, and an ideal error dynamic is formed according to a power attraction law; and according to an ideal error dynamic equation, an e/v signal conversion module is constructed, a signal obtained by calculating through the controller is used as control input of a controlled servo object, and the position servo system changes together with the reference signals by completely eliminating half-cycle symmetrical interference signals. By the half-cycle repetitive controller, the internal memory of the controller can be obviously reduced and the periodic interference is quickly and completely suppressed under the half-cycle symmetrical reference signals, and the half-cycle repetitive controller has high cost performance.

The invention provides a method for controlling axial direction of a high-precision magnetic bearing based on an interference observer. The method consists of a controller and the interference observer, wherein the interference observer comprises a Q filter and a rationalization generalized object inverse QGn part; the controller in a control system calculates according to displacement deviation to obtain basic control quantity so as to form a position closed loop control system; an interference value obtained by observation of the interference observer is negatively fed back into the basic control quantity to compensate exterior interference; and the formed current control quantity drives power amplification to realize high precision suspension of the magnetic bearing. The method leads differences caused by both exterior interference and objective parameter variation to be equivalent to a control input end, and introduces equivalent compensation into the control quantity to realize interference inhabitation. The method can carry out online observation and effective inhabitation against exterior interference which is not modeled or known, thereby improving control precision of suspension, and contributing to stability of the system.

The invention discloses a dual-polarization Doppler weather radar ground clutter inhibition method based on fuzzy logic, and the method comprises the steps: processing volume scanning data of a dual-polarization Doppler weather radar into 360 radial lines, wherein the interval between each two adjacent radial lines is one degree, and the data of each radial line comprises seven echo characteristic physical quantities: intensity, a mean Doppler speed, a spectrum width, a difference reflectivity factor, a difference propagation phase shift, and a correlation coefficient; setting the seven physical quantities which respectively comprise the intensity, the mean Doppler speed, the spectrum width, the difference reflectivity factor, the difference propagation phase shift, and the correlation coefficient; enabling seven fuzzy results to be assigned with corresponding weight values, carrying out accumulating and obtaining a ground clutter criterion of one echo point; Determining that the intensity echo of the point is the ground clutter when the ground clutter criterion of one echo point is greater than a threshold value; inhibiting the ground clutter of the dual-polarization Doppler weather radar through the ground clutter criterion of each echo point, and compensating a hole of a current layer after clutter inhibiting through employing the echo intensity value of a corresponding point in an upper layer in the volume scanning data.

The invention provides an improved method which adopts a spiral phase plate to generate vortex beams so as to carry out edge extraction, belongs to the field of optical scanning and image reconstruction, and mainly solves a problem of suppressing the spiral phase plate to diffract side lobes. In an optical scanning holographic system which carries out edge extraction by adopting the spiral phase plate, suppression for the side lobes is realized through reducing the radius of the spiral phase plate, and a frequency domain expression of the corrected vortex beams is provided, thereby improving the resolution of edge extraction. The method provided by the invention effectively improves the resolution of edge extraction, and the side lobe suppressing method is applicable to various fields.

The invention belongs to the field of radar technologies, relates to designs for transmission waveforms of centralized MIMO (multiple input multiple output) radar, and discloses a method for hierarchically designing transmission waveforms of MIMO radar for detecting targets in clutter. The method includes steps of 1, building an MIMO radar signal model and acquiring the intensity of the clutter in a space domain and mainlobe response priori knowledge in a time domain; 2, designing autocorrelation matrixes Rx of transmission signals on the basis of intensity priori knowledge of the clutter in the space domain; 3, combining each optimal mainlobe synthesized signal (MSS) with a mismatched filter to suppress mainlob clutter signals; 4, designing transmission waveform matrixes under constant-modulus conditional constraints. The method has the advantages that the clutter suppression performance can be improved, and accordingly the radar can be used for detecting the targets in the heavy clutter.

The invention provides an ore dressing method for lead-zinc-silver poly-metallic ores. Lead-silver concentrates and zinc concentrates are finally obtained through the steps of raw ore grinding, lead fast roughing, lead slow roughing, lead scavenging, lead fast concentration, lead slow concentration, zinc fast roughing, zinc slow roughing, zinc scavenging, zinc fast concentration and zinc slow concentration. The lead-zinc-silver poly-metallic ores sorted by the ore dressing method provided by the invention are good in sorting index and high in separation efficiency; the ore dressing method is a lead-zinc-silver ore dressing method which is stable, efficient, strong in adaptive capacity, good in sorting effect, high in comprehensive recovery index and low in production cost and is suitable for popularization and application.

The invention discloses an elastic body aircraft adaptive constrained tracking control indirect method. The objective of the invention is to solve the technical problem of low possibility of realizing adaptive tracking of reference instruction signals when an elastic body aircraft has input and state saturation constraints. The method includes the following steps that: a feedforward system is designed based on an instruction former, and tracked signals and the pulses of the former are subjected to convolution, so that new forming signals can be obtained and are adopted as the input of a subsequent feedback system; the design of the feedback system is decomposed into a velocity subsystem, a height subsystem and an elasticity subsystem, and the influence of elastic modality in rigid body dynamic is considered as elastic interference, and uncertain parameters and an external disturbance introduction nominal model are used in combination, and therefore, a controlled system can be obtained; and a saturation constrained adaptive control method can be realized for the controlled system through utilizing an instruction filter and an auxiliary system, and tracking for the forming signals in the feedforward system can be realized, and closed-loop system signals can be uniformly and ultimately bounded, and suppression on elastic modality deformation and vibration can be realized.

The invention relates to a virtual impedance based DC-side fault current suppression method of a modular multilevel converter (MMC), belonging to the technical field of power transmission. A DC-side fault of the MMC can cause overcurrent of a switching device; and based on a traditional control strategy, a virtual impedance parallel circuit in a primary system is mapped to a controller by a feedback function, DC bus impedance is equivalently risen, thus, instantaneous rising speed of a fault current when a fault occurs in a DC side of the MMC is effectively prevented without increasing the fault current rising speed of other types of faults. In the core scheme, firstly, the DC bus voltage and current of a MMC system and the active power of a PCC point of an AC side are measured in real time; secondly, if the virtual impedance circuit is connected in series to a DC bus, the DC voltage deviation and the active power deviation are calculated when the DC current passes through the virtual circuit; and finally, the associated deviation correction quantity is additionally added to a measurement value of an active power type control quantity of a DQ decoupling controller for correction.

The invention discloses a parallel circulating-current restraining and neutral-point balancing method of a T-type three-level photovoltaic grid-connected inverter. The method for achieving a neutral-point balance comprises the following steps: step one, converting three levels into a two-level SVPWM, figuring out a status switching time for each phase bridge arm on the basis of the SVPWM; and step two, adjusting the status switching time for each phase bridge arm, thereby acquiring a final PWM signal. After achieved the neutral-point balance, a corrected value of a small vector is figured out based on a PI controller; accordingly, a circulating-current restraint is achieved by changing a turn-on time of the small vector. The adopted neutral-point balancing method is able to deal with fluctuations of capacitors on a direct current side, and is able to improve the quality of output waveforms by a certain degree. The parallel circulating-current restraining and neutral-point balancing method of the T-type three-level photovoltaic grid-connected inverter is able to simply and conveniently achieve the restraint of the circulating current, and is simple in control. The parallel circulating-current restraining and neutral-point balancing method of the T-type three-level photovoltaic grid-connected inverter is able to achieve a neutral-point balance control and the circulating-current restraint, thereby solving the difficulty in connecting T-type inverters in parallel. Comparing to a conventional method of dealing with the circulating current by hardware, the parallel circulating-current restraining and neutral-point balancing method of the T-type three-level photovoltaic grid-connected inverter is lower in cost.

The invention provides a neural network adaptive control method applied to a servo system in order to improve the control accuracy of the servo system, which realizes nonlinear compensation and interference suppression of the servo system and improves the tracking accuracy and the robustness of the servo system. In addition, a speed closed loop is not needed, so the entire system can be quite conveniently designed, is easy to implement in engineering and reduces the cost.

The invention discloses a sound identification method based on a cross acoustic array broadband wave beam formation. The sound identification method comprises steps of using a cross acoustic array to align with a needed direction to collect acoustic signals, 2, performing pre-processing on collected sound, 3, performing DFT (discrete Fourier transform) on processed data of each frame, performing frequency band extraction according to a needed frequency band, 4, performing LSMI-MVDR wave beam formation on the needed direction by the extracted frequency band, 5, performing inverse DFT on a frequency domain signal after the wave beam is formed, 6, performing frame overlapping synthesis according to the framing principle to output a signal, and 7, performing characteristic extraction and classification study and identification. The sound identification method based on cross acoustic array broadband wave beam formation can improve a signal-to-noise ratio of the signal received in an expected direction, inhibits interference signals of other directions, can be applied to a signal processing process of an acoustic identification system and can effectively improve an identification rate and reliability of the identification system on the identification object.

The invention discloses a hydraulic pipeline fluid pulse active inhibition method based on a bilateral overflow principle. The method utilizes a piezoelectric ceramic direct drive type four-way slide valve as an executive component of fluid pulse active control, A and B ports of the slide valve are connected to same side branch of a hydraulic pipeline, and P and T ports of the slide valve are connected with an oil box; and a sine control signal drives the slide valve to finish a periodic motion process, the A and B ports realize twice overflowing through the P and T ports, namely bilateral overflowing, and the generated overflowing flow can completely counteract source pulse flow, thereby realizing the active inhibition of hydraulic pipeline fluid pulse. The active inhibition method provided by the invention has the advantages that (1) the motion frequency of the slide valve is one half of the flow pulse frequency of a hydraulic system to be eliminated; and (2) maximal overflowing flow can achieve the flow of the slide valve when a piezoelectric ceramics actuator is in maximum elongation quantity. The invention provides the fluid pulse active inhibition method for the hydraulic system which has the advantages of high speed, high pressure and high power density, and the fluid pulse active inhibition method is further easily practical.

The invention provides a tunable all-optical microwave photon frequency conversion device without an external electric local oscillator. The tunable all-optical microwave photon frequency conversion device mainly comprises a narrow line width semiconductor laser unit, a non-linear optical loop circuit, a photoelectric detector and a low-pass filter; a saturated stimulated brillouin scattering effect is stimulated under the condition of not providing the external electric local oscillator and a circuit is selected to transmit by the non-linear optical loop circuit to generate anti-Stokes light for carrying out frequency conversion on a radio-frequency signal. Noise waves and noise inferences, caused by an optical local oscillator in traditional microwave photon frequency conversion are reduced. Meanwhile, the radio-frequency signal is subjected to high-order modulation by using a double-drive lithium niobate modulator, so that the tunable all-optical microwave photon frequency conversion is realized.

The invention relates to a Brillouin optical-time-domain analyzer based on a coherence dual-pulse pair sequence technology and a method for restraining common-mode noise by utilizing the same, belongs to the field of optics, and solves the problems that a traditional Brillouin optical-time-domain analyzer is low in spatial resolution, long in measuring signal time and low in signal-to-noise ratio. A laser is adopted, an upper branch of light divided by an optical-fiber coupler I is used as pump light, pulse pairs with different pulse widths can be periodically generated by a field-programmable logic array in a programming manner, and the pulse pairs are continuously and optically modulated to form a coherence pulse pair sequence through a photoelectric modulator; a lower branch provides detection light, the detection light enters a photoelectric modulator after a polarization state is adjusted, upper marginal frequency light and lower marginal frequency light which having the frequency difference of Brillouin frequency shifting gamma B are generated on the basis of carrier light, the pump light consisting of the coherence pulse pair sequence and the modulated detection light has a Brillouin scattering phenomenon in a sensing optical fiber, and two Brillouin signals are detected by a photoelectric detector. The Brillouin optical-time-domain analyzer and the method are suitable for restraining the common-mode noise.