38results about How to "Play the role of filtering" patented technology

The invention discloses a method for predicting a zero crossing point of an ultrasonic signal based on multi-threshold comparison. The problem of poor anti-jamming capability is existent in the traditional zero crossing detection method of performing voltage comparison on a signal and a zero potential and directly determining the zero crossing point of the signal in a measuring way. The method comprises the steps of by adopting a measurement and computation combined method, acquiring sample point parameters in a measuring way by multi-thread comparison, carrying out ultrasonic waveform curve fitting, and computing the zero crossing point of the ultrasonic received signal by a curvilinear equation obtained by fitting. According to the method, the problem of poor anti-jamming capability in the traditional zero crossing detection method is effectively solved, and the precision and reliability of the zero crossing detection of the ultrasonic signal are improved. The method is suitable for various ultrasonic detection fields, in particular for gas ultrasonic flow meters with low signal to noise ratios of received wave signals; and the detection precision and the anti-jamming capability can be greatly improved.

The invention discloses a magnetic-integration three-phase filter transformer. The magnetic-integration three-phase filter transformer comprises a transformer core window, wherein a leakage flux branch plate is arranged in the transformer core window; gaps are respectively reserved between the leakage flux branch plate and an upper yoke and between the leakage flux branch plate and a lower yoke; a high-voltage winding coil and a low-voltage winding coil are respectively wound between core columns and the leakage flux branch plate; a low-voltage winding is positioned on the inside, and a high-voltage winding is positioned on the outside; and a filter capacitor is connected with the low-voltage winding coil in parallel. A filter inductor is integrated with the transformer, so that the size of the integrated body of the inductor and the transformer is small, the inductor and the transformer are light, and materials are saved. The columns of three-phase cores are in magnetic flux with the filter inductor and the transformer simultaneously. When the magnetic flux is highest, common magnetic flux and leakage magnetic flux are in different phases, and magnetic cores can be saved to a certain degree. Four single-phase windings of the transformer also have a filtering function, and substitute an independent filter inductor. Moreover, the number of used copper wires of the transformer and the inductor which are integrated is smaller than the number of used copper wires of the transformer and the inductor which are independent from each other.

The invention discloses an over-voltage protection method for the DC bus voltage of a wind power current transformer and a circuit adopting the same. The method comprises the steps as follows: a square wave signal with a certain amplitude value, a certain frequency and a certain positive duty cycle is generated correspondingly according to the actually needed over-voltage protection value of a DC bus voltage by adopting the software table checking method of a DSP (Digital Signal Processor) chip; the square wave signal is compared with a normal value signal to output a square wave signal with a certain amplitude value, the identical frequency and the identical positive duty cycle, and the circuit completing the first time comparison output is a primary comparison circuit; the square wave signal receives special circuit treatment to be changed into a normal value signal reaching the pre-determinate over-voltage protection value of the DC bus voltage, the normal value signal and the conversion value of the actually detected DC bus voltage are compared to send an output signal to the DSP chip, and the circuit completing the second time comparison output is a secondary comparison circuit; and the DSP chip decides whether overvoltage exits in the DC bus voltage of the wind power current transformer.

The invention relates to a mixer based on the current multiplexing technology. The mixer comprises a trans-conductance stage circuit, a switching stage circuit and a load stage circuit that are connected successively. The trans-conductance stage circuit employs a current multiplexing structure and a source degeneration inductance structure. The trans-conductance stage circuit is used for realizingaccess of a radio-frequency voltage signal, converting the radio-frequency voltage signal into a radio-frequency current signal, and reusing the radio-frequency current signal repeatedly. The switching stage circuit is used for realizing access of a local oscillator signal and a radio-frequency current signal, controlling conduction of a plurality of arranged switching tubes alternately based onthe local oscillator signal, carrying out switching modulation on the radio-frequency current signal by alternate conduction of the plurality of arranged switching tubes, and generating an intermediate-frequency current signal and transmitting the signal to the load stage circuit. The load stage circuit is used for converting the intermediate-frequency current signal into a voltage signal and outputting the converted signal. Compared with the prior art, the mixer has advantages of simple structure, high conversion gain, high linearity, low noise, low power consumption, and good port isolationperformance.

The invention relates to a Ka-band MMIC (monolithic microwave integrated circuit) low-noise amplifier and mainly solves the technical problem that the prior art has high noise coefficient, poor in-band gain flatness and poor linearity. The Ka-band MMIC low-noise amplifier comprises a two-stage amplifier, a gamma / 4 transmission wire structure and a three-stage matching network, the two-stage amplifier comprises a primary field-effect transistor amplifier, a primary gate bias network, a primary drain bias network, a primary source resistor ad primary source capacitor parallel network, a secondary amplifier, a secondary gate bias network, a secondary drain bias network, and a secondary source resistor and capacitor parallel network, the gamma / 4 transmission wire structure comprises a first transmission wire mesh connected with the primary gate bias network and a second transmission wire mesh connected with the primary drain bias network; by using the above technical scheme, the problem iswell solved; the Ka-band MMIC low-noise amplifier is applicable to the field of Ka-band communications.

The invention provides a transverse control method for a pilotless automobile; the method comprises the steps: a vehicle posture collection module collects the state and positioning information of a vehicle, an error calculation module calculates a trajectory tracking error, an LQR controller which does not consider the influence of road curvature obtains a feedback control signal according to the tracking error, and the feedback control signal is sent to a control module; the feedforward controller considering the influence of the road curvature obtains a feedforward control signal according to the tracking error of the error calculation module, initializes Q and R matrix parameters of the LQR controller and PID controller parameters, and uses an adaptive seagull algorithm to find the optimal parameters of the Q and R matrixes and the PID controller so as to obtain a final output signal of the LQR controller; and a front wheel steering command signal is obtained by the sum of a final output signal of the LQR controller and an output signal of the PID embedded feedforward controller. According to the method, the optimal solution of the Q and R matrixes in the feasible region can be quickly found, and the control effect of the controller is fully exerted to realize the transverse control of the pilotless automobile.

The invention discloses a medical big data basic information collection and analysis system, which comprises a first processor, and the output end of the first processor is bidirectionally and electrically connected with a database, an information analysis module and a data transmission module. Through the arrangement of the first processor, the database, the information analysis module, the data transmission module, the data display module, the control terminal, the information collection module, the weight measurement module, the height measurement module, the information input module and the online monitoring module, the problem that current medical big data cannot be well applied to the life of people is solved; the medical big data basic information collection and analysis system can monitor the daily physical state of people, can collect the symptoms of various diseases and the information of patients, analyzes and compares the symptoms and the information, improves the diagnosis accuracy, can remind people in time when abnormal conditions occur, and improves the diagnosis efficiency. And alarm and rescue can be carried out in time.

The utility model discloses a processing circuit used for improving the performance of the audio equipment, and the processing equipment thereof. The processing equipment comprises a casing body, the input terminal interface of an audio host machine is arranged at one side of the casing body, the input terminal interface of a power supply is arranged at the other side of the casing body, a protective tube with filtering function is connected on the anode power wire of the input terminal of the audio host machine in series, and a capacitor is bridged between the anode power wire of the input terminal and the cathode power wire of the input terminal of the audio host machine. The processing equipment has the advantages that all sorts of harmful resonance in the circuit can be effectively restrained through the capacitor, and the capacitor plays the role of filtering; the protective tube with the filtering function can effectively restrain all sorts of harmful resonance in the circuit, and plays the role of filtering, reduces the impedance caused by vibration, and improves the degree of purity and the stability of the power supply, the higher harmonics components harmful to the signals are eliminated through the optimization of the quality of the power supply, and the powerful output capability is provided for the machine through the high-quality abundant electric current.

The invention discloses a wireless and magnetic field induction technology combined high precision positioning technology and a corresponding sensor device. The specific technology includes that: (1) a matrix distribution analog Hall voltage detection way is adopted; (2) a wireless radio frequency technology is employed to identify landmark information, and positioning and identification are combined into one; (3) the indoor and outdoor general positioning sensor is not disturbed by rain, snow, thunder, electricity and other environmental factors; and (4) the positioning sensor and method support multi-interface communication and multi-module combination. Compared with current traditional magnetic induction positioning technology, the positioning sensor and method provided by the invention have the advantages of high positioning precision, good stability, good scalability, low cost, concise connection line, and strong anti-interference ability, etc., and are suitable for high precision mobile robot magnetic stripe navigation under various environments.

The embodiment of the invention provides a target detection method and system based on a feedback mechanism. The method comprises: obtaining a to-be-detected target; inputting the to-be-detected target into an improved IFF target detector to obtain a target detection result, wherein the improved IFF target detector is obtained by adding an IFF module based on a target detector. According to the embodiment of the invention, the IFF feedback module is additionally arranged in the existing target detector, the last prediction result is used as reference information to be fed back to the feature map, the filtering effect can be achieved, the activated area of the feature map can be more concentrated in the target area, and the coupling relation between the category information and the positioninformation can be captured by a network through fusion.

The present invention discloses a fuse tube with the function of wave filtration, and the fuse tube includes a metal wire and a tube; wherein, the metal wire is arranged in the tube which is filled with granular electric wave absorption materials. The granular size of the electric wave absorption materials stands at 50 items to 300 items. The advantage is that the tube is filled with granular electric wave absorption materials that can well absorb or isolate the interference of miscellaneous waves, at the same time, reduce and restrain the influences of the miscellaneous wave interference produced in the working of the machine on other equipments via a power supply loop. By entering into the front end of the machine power supply, the function of wave filtration can be effectively broughtinto full play, thus letting the machine have better anti-interference capability in the increasingly serious ambience of electromagnetic interference and have more stable working performance and thestate of the machine.

The invention discloses a magnetic-integration three-phase filter transformer. The magnetic-integration three-phase filter transformer comprises a transformer core window, wherein a leakage flux branch plate is arranged in the transformer core window; gaps are respectively reserved between the leakage flux branch plate and an upper yoke and between the leakage flux branch plate and a lower yoke; a high-voltage winding coil and a low-voltage winding coil are respectively wound between core columns and the leakage flux branch plate; a low-voltage winding is positioned on the inside, and a high-voltage winding is positioned on the outside; and a filter capacitor is connected with the low-voltage winding coil in parallel. A filter inductor is integrated with the transformer, so that the size of the integrated body of the inductor and the transformer is small, the inductor and the transformer are light, and materials are saved. The columns of three-phase cores are in magnetic flux with the filter inductor and the transformer simultaneously. When the magnetic flux is highest, common magnetic flux and leakage magnetic flux are in different phases, and magnetic cores can be saved to a certain degree. Four single-phase windings of the transformer also have a filtering function, and substitute an independent filter inductor. Moreover, the number of used copper wires of the transformer and the inductor which are integrated is smaller than the number of used copper wires of the transformer and the inductor which are independent from each other.

The invention relates to the field of low-voltage power supply, in particular to a low-voltage current-limiting constant-voltage device. A current limiting reactor and a three-dimensional roll core autotransformer are connected in series with a low-voltage output end of a power distribution transformer, a multi-tap voltage regulator excitation winding is arranged an output end of the three-dimensional roll core autotransformer and has a plurality of shifts, each shift output is connected with a switch, and each switch is connected with a control chip. By means of current-limiting reactive characteristic, a surge can be absorbed, so that a large-current impact can be lagged, an instantaneous voltage drop of a system is reduced, the system stability is improved, an effect of filtering is achieved, a power factor of the system is improved, and meanwhile, the safety of the three-dimensional roll core autotransformer is protected.

The present invention relates to a parameter identification method of oil-paper insulation Debye circuit based on self-adaptive sampling interval Prony algorithm. The method improves the traditional Prony algorithm according to the physical characteristics of the Debye equivalent model depolarization current exponential function superposition. The sampling interval can accurately solve the time constant range, realize the adaptive selection of the sampling interval, and use the adaptive sampling interval to perform Prony fitting on the relaxation sub-spectral line of the corresponding time constant; after obtaining the sub-spectral line parameters, substitute it into Debye et al. The equivalent circuit parameter identification formula is used to realize the identification of equivalent circuit parameters. The inventive method avoids the subjectivity of artificial point selection and sampling interval selection, plays a filtering role on the measured depolarization current with noise interference, and accurately and uniquely realizes the identification of the Debye equivalent circuit parameters of the oil-paper transformer.

The embodiment of the invention discloses a rectifier-bridge-free power-taking circuit formed by using MOS tubes and diodes. With the provided circuit, a technical problem of multi-stage losses caused by energy conversation at multiple places in the rectifier-bridge-included rectification conversion circuit in the prior art can be solved. The rectifier-bridge-free power-taking circuit comprises a power-taking boost module, a rectification module connected with the power-taking boost module electrically, and a filter and voltage-stabilizing module connected with the rectifier module electrically. The rectification module consists of a first MOS tube S1, a second MOS tube S2, a first diode Ds1, a second diode Ds2, a third diode D1, and a fourth diode D2.