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44 results about "Zero-order hold" patented technology

The zero-order hold (ZOH) is a mathematical model of the practical signal reconstruction done by a conventional digital-to-analog converter (DAC). That is, it describes the effect of converting a discrete-time signal to a continuous-time signal by holding each sample value for one sample interval. It has several applications in electrical communication.

Nonlinear multi-time-scale delay system modeling and control method

InactiveCN103592850ATroubleshoot poor control performanceHigh precision control to achieveAdaptive controlDiagnostic Radiology ModalityIntegrator
The invention discloses a nonlinear multi-time-scale delay system modeling and control method and belongs to the technical field of controlling of complex systems. The method is based on the UDTTDFSPM and combined with a spectral norm and linear matrix inequality method, a robust combination controller is designed for controlled NMTSTDSs, and high-precision and stable control of the NMTSTDSs is achieved. According to a dynamic model of the NMTSTDSs, an uncertainty continuous time delay obscurity singular perturbation model of the NMTSTDSs is set up, a proper sampling period is selected, a zero-order holder method is adopted to perform discretization on the obtained continuous model, and the UDTTDFSPM of the NMTSTDSs is obtained. The robust combination controller is designed on the basis and is composed of an obscurity slow state feedback controller and an output integrator. The nonlinear multi-time-scale delay system modeling and control method has the advantage of solving the problem of steady-state errors which are caused by system external disturbance and the fast modality of the NMTSTDSs and cannot be solved by an existing modeling and control method, and the control performance of the NMTSTDSs is greatly improved. The nonlinear multi-time-scale delay system modeling and control method is used for controlling the simulation result of postures of a CE150 helicopter, and validity of the method can be shown.
Owner:AUTOMATION RES & DESIGN INST OF METALLURGICAL IND

Markov jump based distributed event triggered filtering system and design method thereof

The invention relates to a Markov jump based distributed event triggered filtering system and a design method thereof. The system comprises N filtering links, and is characterized in that each filtering link comprises a sensor, an event trigger, a zero-order retainer and a filter which are sequentially connected, the sensors are connected with a measured object, the filter in each filtering link further performs communication connection with the other neighbor filters, the communication topology among the N filters in the system is of a non-homogeneous Markov jump mode, the mutually connected filters perform information exchange under each type of non-homogeneous Markov link topology, and the filter in each filtering link is further connected with the corresponding event trigger in the filtering link. Compared with the prior art, the Markov jump based distributed event triggered filtering system has good anti-noise capacity, effectively reduces the number of data transmission times under the premise of ensuring the filtering performance and saves network resources.
Owner:TONGJI UNIV

Switched-current oscillator for clock-frequency spreading

A switched-current oscillator having a dc current source adapted to charge a capacitor so that the capacitor charging time is controlled based on a sequence of (pseudo)randomly selected values, each of those values defining a corresponding charging time. A discharge device is adapted to discharge the capacitor if the voltage across the capacitor reaches a threshold voltage, at which point the next value in the sequence is selected to determine the next charging time. A square-wave clock signal having spread-spectrum characteristics is generated in the oscillator by using the series of charge-discharge cycles corresponding to the sequence of randomly selected values to toggle a flip-flop operating as a delay line and zero-order hold.
Owner:AVAGO TECH INT SALES PTE LTD

Transverse dynamic control method for intelligent car in driving process based on driver characteristics

The invention discloses a transverse dynamic control method for an intelligent car in the driving process based on driver characteristics. The transverse dynamic control method comprises the followingsteps that step 1, a two-degree-of-freedom car dynamics model is established as a reference model; step 2, a driver model reflecting the operating characteristics of a driver is established; step 3,a pre-targeted link is established; step 4, a closed-loop control system is established according to the reference model, the driver model and the pre-targeted link; step 5, a zero-order holder is used for discretizing the established closed-loop control system; step 6, a least square identification function is established; and step 7, the loss function for minimizing the position of the car is used as a target, the pre-targeted time is determined according to the delay time and the inertia time, the pre-targeted distance is determined through the preview time, and then the delay time and theinertia time are calculated iteratively, so that the purpose of dynamically determining all parameters is achieved. According to the transverse dynamic control method for the intelligent car in the driving process based on the driver characteristics, the consistency of the models during path following is ensured, and meanwhile, the riding comfort is improved.
Owner:CHONGQING UNIV

Modeling and control method for complex circuit system with small inductances or capacitances

InactiveCN103645646ATroubleshoot poor control performanceAchieve high precision controlSimulator controlCapacitanceLinear matrix
Disclosed is a modeling and control method for a complex circuit system with small inductances or capacitances (CCSWSIOCs) and the method belongs to the technical field of complex-circuit-system control. The method is based on an UDTFSPM (uncertain discrete time fuzzy singularly perturbed model) and combines methods of spectral norm and linear matrix inequalities to design an RFSOFC (robust fuzzy static output feedback controller) for controlled CCSWSIOCs so as to realize high-precision control of the CCSWSIOCs. According to a dynamical model of the CCSWSIOCs, an uncertain continuous-time fuzzy singularly perturbed model is established. An appropriate sampling period is selected and a zero-order holder method is employed to perform discretization on the continuous-time fuzzy singularly perturbed model so as to obtain the UDTFSPM of the CCSWSIOCs and thus the RFSOFC is designed on the basis. The advantages of the method are that problems of incapability of elimination of instability or large steady-state errors resulted from the internal minute inductances or capacitances of the CCSWSIOCs in the prior modeling and control methods are solved and control performance of the CCSWSIOCs is improved significantly. The modeling and control method for the complex circuit system with the small inductances or capacitances is applied to precision control of a Van der Pol circuit system to perform simulation verification and validity of the method is shown.
Owner:AUTOMATION RES & DESIGN INST OF METALLURGICAL IND

Adaptive high-order digital-to-analog conversion

Techniques for performing digital-to-analog conversion with first-order or higher-order hold using a simple analog circuit for signal reconstruction and employing feedback control techniques are described. In one design, a digital-to-analog conversion circuit includes an inverse model circuit, a feedback circuit, a zero-order hold (ZOH) circuit, and an analog circuit. The inverse model circuit processes a digital input signal and provides a first digital signal. The feedback circuit receives the first digital signal and an analog output signal from the analog circuit, performs low frequency noise filtering, and provides a second digital signal. The ZOH circuit converts the second digital signal from digital to analog with zero-order hold and provides an analog input signal for the analog circuit. The analog circuit operates on the analog input signal and provides the analog output signal. The analog circuit may be a simple circuit having one or more poles.
Owner:QUALCOMM INC

Dual-loop compound control method of unified power quality controller

ActiveCN107947171AImprove the defect of poor steady-state performanceReduce tracking errorAc network voltage adjustmentPower qualityThree phase converter
The present invention relates to a dual-loop compound control method of a unified power quality controller (UPQC). The method comprises the following steps of: (1) employing a UPQC topology structurechart of a three-phase three-wire system to establish a mathematical model in a synchronous rotating reference frame; (2) performing double closed-loop voltage control of the UPQC: taking a serial three-phase converter circuit as a voltage source, outputting a compensation voltage with a size being the same as the difference of a load voltage and a power grid voltage and with a direction being opposite to the load voltage and the power grid voltage, and obtaining a sine load voltage through double closed-loop PI control; (3) taking a parallel three-phase converter circuit as a current source,and outputting a compensation current with a size being the same as the difference of a power grid current and a load current value and with a direction being opposite to the power grid current and the load current value; (4) designing a current loop PI, and adding a zero-order holder in a control model; (5) designing a repetitive controller: establishing a transfer function of the repetitive controller; and (6) combining a PI control inner loop and a repetitive controller outer loop to perform recombination coordination control, tracking a current compensation instruction, outputting the compensation current, and indirectly controlling a power grid input current as a sine current. The dual-loop compound control method of the unified power quality controller can effectively improve the traceability and the compensation performance.
Owner:LANZHOU UNIVERSITY OF TECHNOLOGY

Motor driving device and electric power steering apparatus

In a motor driving device where a motor having a winding wire with small inductance value is driven by a digital control means comprised of control means including a current command value calculating means, a current control means and a PWM control means whose sampling periods are different from each other, when discrete signals sampled by the respective control means are zero-order-held, a motor current includes a lot of higher harmonic waves due to a quantization error, thereby increasing a motor noise. When an n-th-order hold means is provided between the respective control means with different sampling periods, the quantization error can be reduced remarkably, and thus the higher harmonic wave components included in the motor current are reduced, thereby greatly reducing the motor noise.
Owner:NSK LTD +1

Slide form control method, system and device and computer readable storage medium

The invention discloses a slide form control method, system and device based on a Markov jump system and a computer readable storage medium. The system comprises a controlled system, a sensor, a firstevent detector, a first zero-order holder, an observer, a second event detector, a second zero-order holder and the closed loop Markov jump system of a controller, and the controlled system, the sensor, the first event detector, the first zero-order holder, the observer, the second event detector, the second zero-order holder and the closed loop Markov jump system of the controller satisfy a preset stable condition; according to the stable condition, a first positive weighting matrix preset in the first event detector is larger than 0, a second positive weighting matrix preset in the first event detector is larger than 0, a positive definite matrix is larger than 0, and a matrix carrying unknown and known conditions of the transition probability is considered. According to the slide formcontrol method, system and device based on the Markov jump system and the computer readable storage medium, by presetting the stable condition in which the unknown and known conditions of the transition probability of the controlled system are considered, the overall system is more stable; meanwhile, through the event detectors, the communication frequency of the overall system is reduced, and blockage of an information channel is avoided; the observer can observe the state of unknown states in the controlled system, so that the controlled system also runs more stably.
Owner:GUANGDONG UNIV OF TECH

Self-driven sampling system and sampling method of a teleoperated robot

The invention relates to a remote control robot self-driving sampling system. The system comprises a remote control robot, a sensing mechanism, a data buffer area, a data processing module, a signal generator, a clock module, a central processor module, an execution mechanism, an information display module and a communication module, wherein the sensing mechanism and the execution mechanism are installed on the remote control robot; the data buffer area, the data processing module, the signal generator and the clock module are connected in sequence and then connected with the sensing mechanism; the sensing mechanism comprises a sensor and a camera; the data sampled by the sensing mechanism are transmitted to the central processor module through a communication network; and a control instruction of the central processor module is transmitted to the execution mechanism through the communication network. The execution mechanism is a zero-order holder. The invention also discloses a sampling method of the system. By arranging the data buffer area, the data processing module, the signal generator, the clock module, the central processor module and the like, and by connecting the components with various physical devices reasonably, the self-driving sampling of the remote control robot is realized. The hardware is connected simply; the method for realizing the self-driving sampling is simple, convenient and practicable; the network load can be reduced; and the operation performance of the remote control robot is modified, and thus the system has practical application and population value.
Owner:JIANGSU UNIV OF SCI & TECH

Left-growth double-edge UPWM signal frequency spectrum estimation method based on digital PWM generator

ActiveCN110261678ACalculation is simple and convenientEasy to analyzeSpectral/fourier analysisFrequency spectrumDiscretization
The invention provides a left-growth double-edge UPWM (Uniform-sampling Pulse Width Modulation) signal frequency spectrum estimation method based on a digital PWM generator. The method comprises the steps of: performing discretization and quantization of a left-growth double-edge second-level UPWM signal output by a digital PWM generator on a time domain to obtain a series of discrete points; adopting the distribution rule of the amplitudes of the obtained discrete points, performing discrete Fourier transform for the discrete points, and multiplying a transform result by the frequency response function of a zero-order keeper, so that a left-growth double-edge second-level UPWM signal spectrum estimation expression is obtained. The second-level UPMW signal spectrum estimation expressions obtained by modulating the input signals of the digital PWM generator before and after the inversion of the input signal are subtracted to obtain a corresponding third-level UPWM signal spectrum estimation expression. The method provided by the invention can directly obtain the frequency spectrum of the left-growth double-edge UPWM signal under the condition that the input modulation signal is a digital signal.
Owner:ZHENGZHOU UNIVERSITY OF LIGHT INDUSTRY

Multifunctional signal generator correction method and multifunctional signal generator

The invention relates to a multifunctional signal generator device, and discloses a multifunctional signal generator correction method and a multifunctional signal generator, wherein multifunctional signal generator comprises a main control unit, an FPGA unit and a DAC unit. The method comprises the following steps: transmission of wavetable data: a main control unit sends the wavetable data and configures the frequency of the wavetable data, and transmits a wavetable file and the frequency to the FPGA unit; and correction of the waveform data: the FPGA unit stores and reads the received wavetable data, corrects the wavetable data through an amplitude-frequency correction algorithm, and transmits the corrected waveform data to the DAC unit. According to the zero-order retention characteristic of the DAC, the amplitude correction is carried out before the digital signal is input into the DAC, so that the amplitude-frequency distortion is corrected, and the amplitude-frequency characteristic of the output signal of the multifunctional signal generator system is greatly improved.
Owner:杭州加速科技有限公司

A synovium control method, system, device and computer readable storage medium

The invention discloses a slide form control method, system and device based on a Markov jump system and a computer readable storage medium. The system comprises a controlled system, a sensor, a firstevent detector, a first zero-order holder, an observer, a second event detector, a second zero-order holder and the closed loop Markov jump system of a controller, and the controlled system, the sensor, the first event detector, the first zero-order holder, the observer, the second event detector, the second zero-order holder and the closed loop Markov jump system of the controller satisfy a preset stable condition; according to the stable condition, a first positive weighting matrix preset in the first event detector is larger than 0, a second positive weighting matrix preset in the first event detector is larger than 0, a positive definite matrix is larger than 0, and a matrix carrying unknown and known conditions of the transition probability is considered. According to the slide formcontrol method, system and device based on the Markov jump system and the computer readable storage medium, by presetting the stable condition in which the unknown and known conditions of the transition probability of the controlled system are considered, the overall system is more stable; meanwhile, through the event detectors, the communication frequency of the overall system is reduced, and blockage of an information channel is avoided; the observer can observe the state of unknown states in the controlled system, so that the controlled system also runs more stably.
Owner:GUANGDONG UNIV OF TECH

S-domain model of integrated frequency-modulated continuous wave digital frequency synthesizer

The invention belongs to the technical field of integrated circuit design modeling, particularly discloses an s-domain model of an integrated frequency-modulated continuous wave digital frequency synthesizer, and provides a frequency-based modeling method. By using an accumulator model, a pulse switch, a charge pump and an on-chip capacitor are modeled; through the combination of an analog integrator, an ideal sampler, a zero-order retainer, a quantizer and a differentiator, a digital frequency converter is modeled, so that the prediction accuracy of the model is greatly improved; a normalized gain module expression is deduced, so that the model can carry out accurate prediction only by virtue of the accuracy of time-to-digital converter, loop bandwidth and crystal frequency during frequency error and phase noise prediction. The s-domain model can accurately predict the frequency error of a frequency-modulated continuous wave produced by the frequency synthesizer, and the phase noise of dot frequency.
Owner:FUDAN UNIV

Tactile communication fault tolerance method and system based on hybrid prediction

The invention relates to a tactile communication fault tolerance method and system based on hybrid prediction, and the method comprises the steps: carrying out the prediction compression of to-be-transmitted data during the transmission of data, and only transmitting a data frame with the relative deviation between a prediction value and a real value greater than a dead zone parameter, so as to reduce the amount of data needing to be transmitted; when the data is received, if missing data is encountered, adding 1 to the count, comparing the current count value n with a previously received prediction threshold L, if n is greater than L, predicting the missing data by adopting a zero-order preserving prediction algorithm, and otherwise, predicting the missing data by adopting an LSTM model;and if the data is received, resetting the count value, and obtaining a newly received prediction threshold L while the prediction value is a real value. By setting the continuous prediction threshold, the receiving end can autonomously select a relatively conservative prediction algorithm, the influence brought by accumulated errors caused by continuous prediction is reduced, and the stability ofthe tactile communication system is further improved.
Owner:FUZHOU UNIV
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