58results about How to "Suppress nonlinearity" patented technology

The invention discloses a high-precision drive and control integration motor which comprises a power supply interface, wherein a load position detection sensor, a reducer, a motor, a motor rotor position detection sensor, and a debugging interface which is connected with a drive and a controller are integrated with a site bus interface, i.e. an output shaft connected with the load position detection sensor is directly connected with a load, two sides of the motor are respectively coaxially connected with the motor rotor position detection sensor and the reducer, the load position detection sensor and the load are coaxially arranged, and signals of the load position detection sensor and the motor rotor position sensor are led to the drive and the controller by shielding wires. The invention leads a system to have better impact and shock resistance property, is more suitable to the industry control environment; the load position detection sensor, the reducer, the motor, and the like are integrated; the backlash nonlinearity is effectively inhibited by a position controller, a speed controller and a current controller, and the system precision is improved.

A duplexer includes an antenna terminal, a first filter connected to the antenna terminal, a second filter that has a passband at a high-frequency side of the first filter and is connected to the antenna terminal, and a resonance circuit that is connected between the second filter and the antenna terminal and includes a first inductor and a first capacitor connected in parallel. Assuming that a passband frequency of the first filter ranges from f_1Low to f_1High (f_1Low˜f_1High) and a passband frequency ranges from f_2Low to f_2High (f_2Low˜f_2High), the resonator has a resonance frequency f_r satisfying:

f_r=(f_2Low˜f_2High)±(f_1Low˜f_1High), or

f_r=2(f_1Low˜f_1High)±(f_2Low˜f_2High).

The invention discloses a device and a method for simultaneous same-frequency full-duplex nonlinear interference suppression. Under the condition of analyzing nonlinear self-interference characteristics of simultaneous same-frequency full-duplex transmitting, receiving and reconstructing channels, suppression is carried out on the nonlinearity of the whole full-duplex system through an additionally arranged feedback channel and through the modes such as mathematical model establishing, nonlinear signal extraction of a self-interference reconstructing channel, self-interference nonlinear signal modeling, nonlinear self-interference suppression of the self-interference reconstructing channel and precise digital self-interference cancellation in allusion to the nonlinear characteristics of the transmitting channel, the receiving channel and the reconstructing channel, and finally nonlinear self-interference in received signals is suppressed to a part nearby bottom noises of a receiver. According to the invention, simultaneous same-frequency interference is eliminated by combining a transmitting terminal and a receiving terminal in allusion to the environments such as high-power, high bandwidth and multipath self-interference signals and the like, and the self-interference cancellation performance is enabled to be the best, thereby not only enabling the spectrum utilization efficiency to be doubled, improving the communication quality of the system, and improving the work stability and the reliability of communication equipment in a simultaneous same-frequency environment.

The invention relates to an ytterbium doped photonic crystal fiber nonlinear polarization rotation mode-locked laser device, which belongs to the technical field of laser devices, and can directly provide laser output with high average power and high pulse energy from a laser oscillator. The laser device is mold-locked on the basis of a nonlinear polarization rotation principle, and is structurally characterized in that 976nm semiconductor laser is transmitted into an aspheric surface collimating mirror from the laser device firstly, passes by a dichroic mirror, is transmitted into a photonic crystal fiber through an aspheric surface focusing mirror, then is transmitted onto a dichroic mirror by an aspheric surface mirror in a collimated mode and reflected onto a 1/4 wave plate, passes by a narrow-band filtering plate and an optical isolator, sequentially passes by a half-wave plate and a 1/4 wave plate, finally passes by the dichroic mirror and is infiltrated into the photonic crystal fiber by the aspheric surface focusing mirror, and a resonant cavity of the laser device is formed. The laser device with the cavity has a simple structure, is easy to debug, can be used for producing laser with high average power and high pulse energy directly, and can be used for laser processing, nonlinear transformation and the like.

A multimode type SAW filter includes a piezoelectric substrate, and IDT groups formed on the piezoelectric substrate, the IDT groups each having multiple IDTs connected in series in which an input/output electrode and a ground electrode are coupled via a floating conductor. Adjacent electrode fingers between adjacent IDTs among the multiple IDTs of the IDT groups include a first electrode finger connected to the floating conductor in one of the IDT groups and a second electrode finger connected to one of the input/output electrode and the ground electrode in another one of the IDT groups.

The invention provides an unmanned aerial vehicle robust attitude control method and device, and an electronic device and relates to the automation control technology field. The method comprises the following steps of acquiring the current state data and the current desired attitude angle of an unmanned aerial vehicle; determining the attitude control input of the unmanned aerial vehicle based oncurrent state data, the current desired attitude angle, and a pre-designed robust attitude controller, wherein the robust attitude controller includes a feedforward controller and an H2 controller designed based on the attitude error model of quaternion representation, and a robust compensator; and according to the attitude control input, controlling the flight attitude of the unmanned aerial vehicle. The feedforward controller and the H2 controller designed based on the attitude error model of quaternion representation can complete flight mode conversion under the condition that coordinate systems are not switched; and the robust compensator can simultaneously restrain the influenced of parameter uncertainty, nonlinearity, coupling dynamics and external disturbances in a whole frequency range, and the tracking performance and the robustness of the unmanned aerial vehicle are improved.

The invention provides a UAV (unmanned aerial vehicle) robust attitude control method and device independent of angular velocity feedback. The method comprises steps as follows: an attitude angle output by a power system of a UAV is collected, and an attitude angle error between the attitude angle and an expected reference quantity is calculated; an estimated value of an attitude angular velocityerror is generated according to the attitude angle error and a nominal control signal; the attitude angle comprises a rolling angle, a pitch angle or a yaw angle; the nominal control signal is updatedaccording to the estimated value; a robust compensation control signal is generated according to the attitude angle error and a current final control signal; the final control signal is updated according to the updated nominal control signal and the robust compensation control signal; the UVA is controlled to execute an attitude corresponding to the attitude angle according to the updated final control signal. According to the method and the device, influence of multiple uncertainty factors such as nonlinearity, coupling, external time-varying interference and the like in the flying process of the UAV can be inhibited, and precision and robustness of UAV attitude control are improved.

The invention relates to a method for correcting nonlinear response of a photomultiplier and a photoelectric detector and a spectrophotometer obtained based on the same, solving the problem of nonlinear response of the current photomultipliers and the problem of low transmittance accuracy of the spectrophotometer caused by the previous problem. The method is characterized by obtaining a correction equation by correcting the photo-electric response curve of the photomultiplier, thereby correcting the electric signal output by the photomultiplier. The photoelectric detector comprises the photomultiplier and a nonlinear response corrector. The spectrophotometer comprises a light source, a monochrometer, a sample cell, the photoelectric detector and a calculation and display device. The photoelectric detector can be used for high accuracy photoelectric detection, and the spectrophotometer can be used for qualitative and quantitative analysis and corresponding optical measurement of the substances.

A digital to analog converting method insensitive to code-dependent distortions is implemented by a digital to analog converter (DAC) having a plurality of unit current sources. A plurality of binary-weighted input codes are received by the DAC and rotated to generate dynamic element matched (DEM) encoded signals. Between the adjacent DEM encoded signals is a purposely added pre-determined return-to-zero (RTZ) code. When the DAC generates analog outputs according to the alternately received DEM encoded signals and the RTZ codes, a zero-voltage phase during the level transition of the analog outputs is obtained by the RTZ codes. With the DEM encoded signals and the RTZ codes, each level transition is independent. Furthermore, code-dependent problems such as mismatch- and transient-related distortion are mitigated by the DEM encoded signals.

The invention comprises continuous-wave laser, pushpull electro optic modulator and electrical signal generator. With adjusting offset voltage, the bias point of modulator is set between midpoint value and minimum value of transmission function, and the continuous-wave is modulated by modulator driven by CSNRZ electrical signal to generate CSNRZ optical signal. The invention also offers a device that can convert CSNRZ optical signal to NRZ optical signal. Being different with RZ and CSRZ, '0'bit and '1' bit corresponding to CSNRZ coder pattern has opposite phase in sign that inhabits either carrier wave component of NRZ optical signal, or keeps good chromatic dispersion.

The invention provides a DC (direct current) motor speed control method based on hybrid self-adjusting fuzzy PID control. The method comprises following steps: firstly, an actual rotating speed n anda given rotating speed nr of a motor are subjected to comparative calculation, a final deviation e and a deviation change rate ec are obtained, the two deviations are subjected to fuzzification in a fuzzy controller, and E and EC after the fuzzification are given to the fuzzy controller for reasoning work, so that kp1 and ki1 after defuzzification are obtained; parameters in a PI controller are adjusted timely, transient and steady conditions in a control process are distinguished with a switching function, finally, a control result is input into a brushless DC motor to realize rotating speedcontrol, and the rotating speed of the motor is controlled. Furthermore, fuzzy control is adopted and is not required to depend on an accurate mathematical model of the controlled motor, so that the controlled motor is more stable in a control state and the nonlinear condition of the controlled motor can be effectively inhibited.

The invention provides a high-precision weak EEG (Electro Encephalo Graph) detection digital-analog hybrid control chip system. The high-precision weak EEG detection digital-analog hybrid control chipsystem is characterized by mainly comprising an amplification filter circuit, an SAR-ADC (Successive Approximation Register-Analog Digital Converter), a digital controller, a radio-frequency circuitand a peripheral circuit; by means of the high-precision weak EEG detection digital-analog hybrid control chip system, the range of the bandwidth of an input signal can be limited; an off-chip filtercomponent is prevented from being used; simultaneously, on one hand, the filter circuit performs chopper amplification bandwidth limiting adjustment and denoising filtering functions; and on the otherhand, the filter circuit provides a frequency pre-anti-aliasing function for the later SAR-ADC circuit. According to the high-precision weak EEG detection digital-analog hybrid control chip system provided by the invention, correction acquisition of EEG signals can be realized; it proves that the designed highly-integrated special high-precision amplification chip and EEG-DSP chip control systemreaches the advanced level at home and abroad; and the high-precision weak EEG detection digital-analog hybrid control chip system has important application value for weak EEG signal extraction and electroencephalogram wearable equipment.

The invention relates to an LQR optimized brushless DC motor speed regulation neutral network PID controller, which is used for improving the control performance of the traditional neutral network PIDcontroller and the traditional LQR optimized PID controller. The designed LQR optimized neural network PID controller (LNPID) adjusts the KP, KI, KD gains of the controller by using a BP neural network, thereby improving the dynamic characteristic and robustness of the controller. The three-layer BP neural network adopted by the invention has strong nonlinear mapping capability, and can effectively inhibit the nonlinear condition of the controlled object. However, the traditional BP neural network is an optimization method of local search, so that the optimal output of the BP neural network is optimized by introducing an LQR control algorithm, and the output data is enabled to be closer to the target PID gain; and finally, the control output value of the controller is inputted into the brushless DC motor to achieve the rotation speed control of the motor. Meanwhile, the LNPID is adopted to continuously monitor the change of the parameters and the real-time feedback of the parameters,so that the control effect is enabled to be ideal.

The linearization control method of a single phase shift modulation DAB converter is disclosed. Through adding a linearization unit between a digital PI controller and a DAB converter, the nonlinear characteristic of a single phase shift modulation DAB converter is restrained. In the method, a DAB converter system is approximately set to be a linear system and oscillation caused by load sudden changes or reference input sudden changes is prevented so as to guarantee the global stability of the DAB converter under different loads and different reference voltages. The method has low operationalcomplexity and is easy to realize, the dynamic performance of a converter system can be increased and the disturbance resistance capability of the converter is enhanced.

The invention provides a tail sitter type unmanned aerial vehicle transition section robust control method based on a nonlinear disturbance observer. Firstly, an H-infinity controller is designed fora nominal model of a tail sitter type unmanned aerial vehicle at a transition section so as to achieve the expected trajectory tracking performance; and then, in order to inhibit the influence by uncertainty, nonlinear characteristics and external interference and to improve the robustness of the system, the nonlinear disturbance observer is designed. Compared with other control methods, accordingto the robust control method, the dynamic and static tracking performance of the tail sitter type unmanned aerial vehicle can be improved, and under the condition of large maneuvering and strong coupling, the influence by the uncertainty, non-linearity and the external interference can be inhibited by the disturbance observer, so that the expected performance is achieved.

A fractional-N phase locked loop (PLL) circuit (104, 600, 800) is provided. The PLL circuit (104, 600, 800) generates a spread spectrum clock (SSC), using average techniques to suppress phase interpolator nonlinearity. The PLL circuit (600, 800) includes fractional dividers (606, 806) with hybrid finite impulse response (FIR) filtering. Furthermore, a small size and low power divider (606, 806) for a hybrid FIR fractional-N PLL circuit (600, 800) is provided.

The invention designs a configurable brushless direct current motor speed regulation fuzzy PID controller, which is used for improving the control performance of a traditional fuzzy PID. The method specifically involves a PID controller in a steady state and a PI and PD type configurable two-stage fuzzy logic controller (CFLC) in a transient state; and a switching function is introduced for switching between the PID and the CFLC based on a speed error, thereby ensuring expected control responses under different conditions. The fuzzy control adopted by the method does not need to depend on an accurate mathematical model of a controlled object and enables the controlled object to be more stable in a control state, and the non-linear condition of the controlled object can be effectively inhibited; in the steady state control process, the error variation is small, and the traditional PID control enables a system to keep stable; and in the transient state control process, the error variation is large, and the configurable two-stage fuzzy PI+PD control can continuously monitor changes of parameters and real-time feedback of the parameters, so that the control effect is idealized.

The invention discloses a lossless method for measuring the content of bagged complex solution components. The method comprises the steps as follows: a modulation device modulates light sources which comprise a transmission light source and a fluorescence excitation light source, a displacement platform controls the light sources to move to double-optical-path points in multiple positions for transmission and excitation of the complex solution respectively, and a spectral receiving device is used for collecting transmission and fluorescence spectra; time series are converted into frequency domains, the transmission spectra in the frequency domain and the fluorescence spectra in the frequency domain are constructed, the ratio of transmission spectra in the two frequency domains in each position is subjected to logarithm calculation, the logarithm is the absorption spectrum of the complex solution in the position, the absorption spectra in the multiple positions and the fluorescence spectra in the double-optical-path frequency domains in the multiple positions are normalized together, results are compared with results of existing chemical analysis, and a mathematical model is established. Absorption spectra under multiple positions and fluorescence spectra in the frequency domains of an unknown complex solution are collected with the same method, normalized and substituted into the mathematical model, and the content of a measured target component is obtained.

The present invention discloses a vibration and non-linear inhibition method for a piezoelectric positioning device. The method comprises the following steps of (1) pre-processing a voltage signal input into the piezoelectric ceramics of the piezoelectric positioning device; (2) subjecting the piezoelectric positioning device to kinetic modeling and obtaining an open-loop transfer function among the key parameters of the piezoelectric positioning device, the input voltage and the output displacement; (3) conducting the closed-loop control of the piezoelectric positioning device based on the integral feedback method; (4) adopting a measurement value of a force sensor between the piezoelectric ceramics and a flexible hinge as a feedback quantity for realizing the feedback control of the piezoelectric positioning device, measuring the output displacement of the flexible hinge by a displacement sensor, and realizing the vibration and non-linear inhibition of the piezoelectric positioning device. According to the invention, the vibration inhibition and the non-linear inhibition are inhibited atr the same time without depending on the model modeling precision. Therefore, the requirements of the modern precision manufacture on the high precision and the high tracking performance of the piezoelectric positioning device can be met. The working efficiency is improved.

The invention relates to a sealing tooth staggered type squeeze oil film damper. The sealing tooth staggered type squeeze oil film damper is arranged outside a bearing in a sleeving mode and comprisesan elastic bearing, a bearing pedestal is arranged outside the bearing, an inner damper ring serves as the head of the elastic bearing, an outer damper ring serves as the bearing pedestal, a rotor issleeved with the bearing, the outer damper ring and the inner damper ring are in clearance fit, an oil film clearance serves as the clearance, an oil supply groove is formed in the outer damper ring,an oil supply hole is formed in the oil supply groove and located above the oil film clearance, sealing teeth are arranged at the ends of the outer damper ring and the inner damper ring in the peripheral direction, and tips of the two sets of sealing teeth are engaged. Through the reasonable design of the technical scheme, the sealing teeth of the inner ring and the outer ring can be completely engaged, a vertical gap is reduced, a lubricating oil flowing out channel is limited, the leakage amount is reduced, and the damping effect is greatly improved.

The invention discloses a colinear frequency mixing ultrasonic detection method for mechanical property degradation of a tank torsion shaft. A coupling agent is utilized to respectively bond a longitudinal wave ultrasonic transducer and a transverse wave ultrasonic transducer on the two sides of a tank torsion shaft torsion fatigue test piece to excite an excitation longitudinal wave and an excitation transverse wave and receive a signal wave. The occurrence time of a frequency mixing wave is worked out through theoretical calculation, the frequency mixing wave signal is added with a calibrated time window for achieving signal judgment, and the interference of a reflected signal caused by curved surfaces at different shaft diameters when the tank torsion shaft test piece is in transition between a parallel section and a non-parallel section is eliminated. The frequency mixing wave signal after windowing is processed by adopting a full-phase inversion method, the all-phase signal of thefrequency mixing wave is subjected to phase reversal processing, and the frequency mixing wave signal is further extracted. Finally, the experimental result subjected to phase reversal processing isprocessed through a spectral analysis method, and a nonlinear energy parameter of energy distribution in a frequency mixing frequency range is extracted from a frequency domain graph of the spectral analysis method.