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ZERO PHASE ERROR REAL TIME CONTROL FOR FLIGHT SIMULATOR SERVO SYSTEM 被引量:5
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作者 LiuJinkun LiuQiang ErLianjie 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2004年第1期132-135,共4页
Flight simulator is an important device and a typical high performanceposition servo system used in the hardware-in-the-loop simulation of flight control system. Withoutusing the future desired output, zero phase erro... Flight simulator is an important device and a typical high performanceposition servo system used in the hardware-in-the-loop simulation of flight control system. Withoutusing the future desired output, zero phase error controller makes the overall system's frequencyresponse exhibit zero phase shift for all frequencies and a very small gain error at low frequencyrange can be achieved. A new algorithm to design the feed forward controller is presented, in orderto reduce the phase error, the design of proposed feed forward controller uses a modified plantmodel, which is a closed loop transfer function, through which the system tracking precisionperformance can be improved greatly. Real-time control results show the effectiveness of theproposed approach in flight simulator servo system. 展开更多
关键词 Zero phase error Flight simulator Servo system
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QFT control based on zero phase error compensation for flight simulator 被引量:5
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作者 Liu Jinkun He Yuzhu 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2007年第1期125-131,共7页
To improve the robustness of high-precision servo systems, quantitative feedback theory (QFT) which aims to achieve a desired robust design over a specified region of plant uncertainty is proposed. The robust design... To improve the robustness of high-precision servo systems, quantitative feedback theory (QFT) which aims to achieve a desired robust design over a specified region of plant uncertainty is proposed. The robust design problem can be solved using QFT but it fails to guarantee a high precision tracking. This problem is solved by a robust digital QFT control scheme based on zero phase error (ZPE) feed forward compensation. This scheme consists of two parts: a QFT controller in the closed-loop system and a ZPE feed-forward compensator. Digital QFT controller is designed to overcome the uncertainties in the system. Digital ZPE feed forward controller is used to improve the tracking precision. Simulation and real-time examples for flight simulator servo system indicate that this control scheme can guarantee both high robust performance and high position tracking precision. 展开更多
关键词 Quantitative feedback theory Zero phase error Feed forward compensation Servo system Flight simulator
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Study on fast calibration of a ULA's gain and phase error 被引量:3
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作者 ZHU Guang-ping SUN Hui ZHANG Ming-hui 《Journal of Marine Science and Application》 2007年第2期64-69,共6页
Array calibration is important in engineering practice. In this paper, fast calibration methods for a ULA's gain and phase errors both in far and near fields are proposed. In the far field, using a single sound so... Array calibration is important in engineering practice. In this paper, fast calibration methods for a ULA's gain and phase errors both in far and near fields are proposed. In the far field, using a single sound source without exact orientation, this method horizontally rotates the array exactly once, performs eigen value decomposition for the covariance matrix of received data, then computes the gain and phase error according to the formulas. In the near field, using the same single sound source, it is necessary to rotate the array horizontally at most three times, build equations according to geometric relations, then solve them. Using the formula proposed in this paper, spherical waves are modified into plane waves. Then eigen values decomposition is performed. These two calibration methods were shown to be valid by simulation and are fast, accurate and easy to use. Finally, an analysis of factors influencing estimation precision is given. 展开更多
关键词 ULA single sound source gain and phase error eigen values decomposition
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Ultra wideband CMOS digital T-type attenuator with low phase errors 被引量:1
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作者 Chao Fan Yahua Ran Liqun Ye 《Journal of Semiconductors》 EI CAS CSCD 2022年第3期57-59,共3页
A proposed inductive-phase-compensation ultra wideband CMOS digital T-type attenuator design based on an analysis of minimising phase errors is presented in this letter.In a standard CMOS technology,the proposed atten... A proposed inductive-phase-compensation ultra wideband CMOS digital T-type attenuator design based on an analysis of minimising phase errors is presented in this letter.In a standard CMOS technology,the proposed attenuator is analytically demonstrated to have low phase errors due to the inductive-phase-compensation network.A design equation is inferred and a wide-band 4dB attenuation bit digital attenuator with low phase errors is designed as a test vehicle for the proposed approach. 展开更多
关键词 ULTRA-WIDEBAND digital T-type attenuator low phase error inductive-phase-compensation CMOS
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Quantitative feedback theory and zero phase error tracking control combined robust control for radar truck leveling simulator 被引量:1
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作者 凌轩 李晓辉 +1 位作者 朱玉泉 冯天麟 《Journal of Shanghai University(English Edition)》 2009年第5期384-390,共7页
Radar leveling system is the key equipment for improving the radar mobility and survival capability. A combined quantitative feedback theory (QFT) controller is designed for the radar truck leveling simulator in this ... Radar leveling system is the key equipment for improving the radar mobility and survival capability. A combined quantitative feedback theory (QFT) controller is designed for the radar truck leveling simulator in this paper, which suffers from strong nonlinearities and system parameter uncertainties. QFT can reduce the plant uncertainties and stabilize the system, but it fails to obtain high-precision tracking. This drawback can be solved by a robust QFT control scheme based on zero phase error tracking control (ZPETC) compensation. The combined controller not only possesses high robustness, but greatly improves the system performance. To verify the effiectiveness and the potential of the proposed controller, a series of experiments have been carried out. Experimental results have demonstrated its robustness against a large range of parameters variation and high tracking precision performance, as well as its capability of restraining the load coupling among channels. The combined QFT controller can drive the radar truck leveling platform accurately, quickly and stably. 展开更多
关键词 radar truck leveling simulator quantitative feedback theory (QFT) parameter uncertainties zero phase error tracking control (ZPETC) high robustness
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Tracking error analysis and simulation of FLL-assisted PLL 被引量:1
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作者 田甜 安建平 张若冰 《Journal of Beijing Institute of Technology》 EI CAS 2012年第4期532-537,共6页
In order to solve problems in high dynamic environment, a frequency-locked loop (FLL) assisted phase-locked loop (PLL) is put forward for carrier tracking. On the basis of the analysis of discriminators, the total... In order to solve problems in high dynamic environment, a frequency-locked loop (FLL) assisted phase-locked loop (PLL) is put forward for carrier tracking. On the basis of the analysis of discriminators, the total phase error of the tracking loop is analyzed and a general error expression is derived. By using linearization and Jaffe-Rechtin coefficients, the performance of a special first order FLL-assisted second order PLL is analyzed to get a closed expression. Analysis results and simula- tions show that there exist an optimal FLL loop bandwidth and a optimal PLL loop bandwidth which can make the phase jitter much less than that when the PLL is used alone. 展开更多
关键词 frequency-locked loop (FLL) assisted phase-locked loop (PLL) phase tracking error Jaffe-Rechtin filter
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A convenient look-up-table based method for the compensation of non-linear error in digital fringe projection 被引量:9
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作者 Chen Xiong Jun Yao +1 位作者 Jubing Chen Hong Miao 《Theoretical & Applied Mechanics Letters》 CAS CSCD 2016年第1期49-53,共5页
Although the structured light system that uses digital fringe projection has been widely implemented in three-dimensional surface profile measurement, the measurement system is susceptible to non-linear error. In this... Although the structured light system that uses digital fringe projection has been widely implemented in three-dimensional surface profile measurement, the measurement system is susceptible to non-linear error. In this work, we propose a convenient look-up-table-based (LUT-based) method to compensate for the non-linear error in captured fringe patterns. Without extra calibration, this LUT-based method completely utilizes the captured fringe pattern by recording the full-field differences. Then, a phase compensation map is established to revise the measured phase. Experimental results demonstrate that this method works effectively. 展开更多
关键词 Phase measurement Digital fringe projection Non-linear error compensation Digital image processing
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Zero phase error control based on neural compensation for flight simulator servo system
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作者 Liu Jinkun He Peng Er Lianjie 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2006年第4期793-797,共5页
Using the future desired input value, zero phase error controller enables the overall system's frequency response exhibit zero phase shift for all frequencies and a small gain error at low frequency range, and based ... Using the future desired input value, zero phase error controller enables the overall system's frequency response exhibit zero phase shift for all frequencies and a small gain error at low frequency range, and based on this, a new algorithm is presented to design the feedforward controller. However, zero phase error controller is only suitable for certain linear system. To reduce the tracking error and improve robustness, the design of the proposed feedforward controller uses a neural compensation based on diagonal recurrent neural network. Simulation and real-time control results for flight simulator servo system show the effectiveness of the proposed approach. 展开更多
关键词 zero phase error servo system neural network robust control flight simulator.
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Effects of systematic phase errors on optimized quantum random-walk search algorithm
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作者 张宇超 鲍皖苏 +1 位作者 汪翔 付向群 《Chinese Physics B》 SCIE EI CAS CSCD 2015年第6期155-163,共9页
This study investigates the effects of systematic errors in phase inversions on the success rate and number of iterations in the optimized quantum random-walk search algorithm. Using the geometric description of this ... This study investigates the effects of systematic errors in phase inversions on the success rate and number of iterations in the optimized quantum random-walk search algorithm. Using the geometric description of this algorithm, a model of the algorithm with phase errors is established, and the relationship between the success rate of the algorithm, the database size, the number of iterations, and the phase error is determined. For a given database size, we obtain both the maximum success rate of the algorithm and the required number of iterations when phase errors are present in the algorithm. Analyses and numerical simulations show that the optimized quantum random-walk search algorithm is more robust against phase errors than Grover's algorithm. 展开更多
关键词 quantum search algorithm quantum random walk phase errors ROBUSTNESS
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The Influence of Carrier Phase Error on the Performances of Digital Image m-QAM Transmission System
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作者 YI Qing-ming WU Wen-si +1 位作者 GUO Jiang-ling HUANG Yuan 《Semiconductor Photonics and Technology》 CAS 2000年第2期105-111,共7页
The effect of carrier phase error in digital image transmission system is discussed. Code error rate and SNR with carrier phase error in Gauss white noise channel are calculated, and the transmission system is simulat... The effect of carrier phase error in digital image transmission system is discussed. Code error rate and SNR with carrier phase error in Gauss white noise channel are calculated, and the transmission system is simulated on computer. 展开更多
关键词 M-QAM CONSTELLATION Carrier phase error Code error rate
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The Role of Phase Errors Distributions in Phased Array Systems Operations
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作者 F. Cannone G. Coviello G. Avitabile 《Journal of Energy and Power Engineering》 2011年第10期985-992,共8页
A comprehensive study on the role of the phase errors distribution on the performances of the phased array systems has been led using a complete and behavioral model for radiation-pattern characteristics. The used mod... A comprehensive study on the role of the phase errors distribution on the performances of the phased array systems has been led using a complete and behavioral model for radiation-pattern characteristics. The used model has many input parameters and it has a lot of features, such as parameters simulations with results analysis, unconventional two-dimensional color graph representation capability in order to show more clearly the results. The results of the study have been discussed and reported. The main achievement of this work is the demonstration that the RMS phase error is a valuable figure of merit of phased array systems but it is not sufficient to completely describe the behavior of a real system. Indeed, this work has shown how the phase errors distribution actually affects the performances of the phased arrays antennas. 展开更多
关键词 Behavioral model phased array RMS phase error phase errors distribution antenna.
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Opto-mechanical-thermal integration analysis of Doppler asymmetric spatial heterodyne interferometer
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作者 WANG Jin-jiang JIANG Lun +3 位作者 TONG Shou-feng PEI Hui-yi CUI Yong GUO Ming-hang 《中国光学(中英文)》 EI CAS CSCD 北大核心 2024年第6期1489-1511,共23页
In order to improve the detection accuracy of Doppler asymmetric spatial heterodyne(DASH)interferometer in harsh temperatures,an opto-mechanical-thermal integration analysis is carried out.Firstly,the correlation betw... In order to improve the detection accuracy of Doppler asymmetric spatial heterodyne(DASH)interferometer in harsh temperatures,an opto-mechanical-thermal integration analysis is carried out.Firstly,the correlation between the interference phase and temperature is established according to the working principle and the phase algorithm of the interferometer.Secondly,the optical mechanical thermal analysis model and thermal deformation data acquisition model are designed.The deformation data of the interference module and the imaging optical system at different temperatures are given by temperature load simulation analysis,and the phase error caused by thermal deformation is obtained by fitting.Finally,based on the wind speed error caused by thermal deformation of each component,a reasonable temperature control scheme is proposed.The results show that the interference module occupies the main cause,the temperature must be controlled within(20±0.05)℃,and the temperature control should be carried out for the temperature sensitive parts,and the wind speed error caused by the part is 3.8 m/s.The thermal drift between the magnification of the imaging optical system and the thermal drift of the relative position between the imaging optical system and the detector should occupy the secondary cause,which should be controlled within(20±2)℃,and the wind speed error caused by the part is 3.05 m/s.In summary,the wind measurement error caused by interference module,imaging optical system,and the relative position between the imaging optical system and the detector can be controlled within 6.85 m/s.The analysis and temperature control schemes presented in this paper can provide theoretical basis for DASH interferometer engineering applications. 展开更多
关键词 Doppler asymmetric spatial heterodyne interferometer interference module imaging optical system opto-mechanical thermal integration analysis phase error temperature control
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Solar image reconstruction method under atmospheric turbulence at Fuxian Lake Solar Observatory
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作者 Sizhong Zou Zhenyu Jin +2 位作者 Kaifan Ji Jun Xu Lei Yang 《Astronomical Techniques and Instruments》 CSCD 2024年第2期128-139,共12页
Strong atmospheric turbulence reduces astronomical seeing,causing speckle images acquired by ground-based solar telescopes to become blurred and distorted.Severe distortion in speckle images impedes image phase deviat... Strong atmospheric turbulence reduces astronomical seeing,causing speckle images acquired by ground-based solar telescopes to become blurred and distorted.Severe distortion in speckle images impedes image phase deviation in the speckle masking reconstruction method,leading to the appearance of spurious imaging artifacts.Relying only on linear image degradation principles to reconstruct solar images is insufficient.To solve this problem,we propose the multiframe blind deconvolution combined with non-rigid alignment(MFBD-CNRA)method for solar image reconstruction.We consider image distortion caused by atmospheric turbulence and use non-rigid alignment to correct pixel-level distortion,thereby achieving nonlinear constraints to complement image intensity changes.After creating the corrected speckle image,we use the linear method to solve the wavefront phase,obtaining the target image.We verify the effectiveness of our method results,compared with others,using solar observation data from the 1 m new vacuum solar telescope(NVST).This new method successfully reconstructs high-resolution images of solar observations with a Fried parameter r0 of approximately 10 cm,and enhances images at high frequency.When r0 is approximately 5 cm,the new method is even more effective.It reconstructs the edges of solar graining and sunspots,and is greatly enhanced at mid and high frequency compared with other methods.Comparisons confirm the effectiveness of this method,with respect to both nonlinear and linear constraints in solar image reconstruction.This provides a suitable solution for image reconstruction in ground-based solar observations under strong atmospheric turbulence. 展开更多
关键词 Astronomical seeing Solar telescopes Solar observatories Astronomy image processing Phase error DECONVOLUTION
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Determination of Total Vector Error of the Phasor Measurement Unit (PMU) Using the Phase Angle Error of a Constant Amplitude Voltage Signal
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作者 Gabriel Musonda Ackim Zulu Charles S. Lubobya 《Journal of Power and Energy Engineering》 2024年第11期34-47,共14页
This paper investigates the effect of the Phase Angle Error of a Constant Amplitude Voltage signal in determining the Total Vector Error (TVE) of the Phasor Measurement Unit (PMU) using MATLAB/Simulink. The phase angl... This paper investigates the effect of the Phase Angle Error of a Constant Amplitude Voltage signal in determining the Total Vector Error (TVE) of the Phasor Measurement Unit (PMU) using MATLAB/Simulink. The phase angle error is measured as a function of time in microseconds at four points on the IEEE 14-bus system. When the 1 pps Global Positioning System (GPS) signal to the PMU is lost, sampling of voltage signals on the power grid is done at different rates as it is a function of time. The relationship between the PMU measured signal phase angle and the sampling rate is established by injecting a constant amplitude signal at two different points on the grid. In the simulation, 64 cycles per second is used as the reference while 24 cycles per second is used to represent the fault condition. Results show that a change in the sampling rate from 64 bps to 24 bps in the PMUs resulted in phase angle error in the voltage signals measured by the PMU at four VI Measurement points. The phase angle error measurement that was determined as a time function was used to determine the TVE. Results show that (TVE) was more than 1% in all the cases. 展开更多
关键词 Phasor Measurement Unit (PMU) Phase Angle error Total Vector error (TVE) State estimation Time Source error Constant Amplitude Signal
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Joint frequency offset tracking and PAPR reduction algorithm in OFDM systems 被引量:4
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作者 Lijun Ge Yingxin Zhao Hong Wu Ning Xu Yu'ang Jin Wenqi Li 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2010年第4期557-561,共5页
This paper presents an algorithm that aims to reduce the peak-to-average power ratio(PAPR) of orthogonal frequency division multiplexing(OFDM) communication systems while maintaining frequency tracking.The algorit... This paper presents an algorithm that aims to reduce the peak-to-average power ratio(PAPR) of orthogonal frequency division multiplexing(OFDM) communication systems while maintaining frequency tracking.The algorithm achieves PAPR reduction by applying the complex conjugates of the data symbol obtained from the frequency domain to cancel the phase of the data symbol.A likelihood estimator is used to obtain the sub-carrier phase error due to the residual carrier frequency offset(RCFO) using the same complex conjugates as a pilot signal.Furthermore,a joint time and frequency domain multicarrier phase locked loop(MPLL) is developed to compensate additional frequency offset.Simulation results show that this algorithm is capable of reducing PAPR without impacting the frequency tracking performance. 展开更多
关键词 orthogonal frequency division multiplexing(OFDM) peak-to-average power ration(PAPR) carrier frequency offset complex conjugate multicarrier phase locked loop(MPLL) phase error.
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THE EFFECT OF IMU INACCURACIES ON AIRBORNE SAR IMAGING 被引量:5
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作者 Mao Yongfei Xiang Maosheng +1 位作者 Wei Lideng Han Songtao 《Journal of Electronics(China)》 2011年第4期409-418,共10页
When using motion compensation approaches based on the measurement of motion sensors, the residual uncompensated motion errors due to measurement instrument inaccuracies contribute to phase errors and hence degrade Sy... When using motion compensation approaches based on the measurement of motion sensors, the residual uncompensated motion errors due to measurement instrument inaccuracies contribute to phase errors and hence degrade Synthetic Aperture Radar (SAR) images. This paper presents a model to compute the phase error caused by Inertial Measurement Unit (IMU) measurement inaccuracies. By analyzing SAR motion compensation method and the effect of lever arm, this model derives the con-tribution of each term of IMU inaccuracies towards the residual uncompensated motion errors and provides a method to calculate each order of the residual phase error. According to the model, com-puted results of the airborne X-band SAR system with POS AV510 accord closely with the actual image quality. 展开更多
关键词 Synthetic Aperture Radar (SAR) Inertial Measurement Unit (IMU) Motion compen-sation Phase error
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THE REALIZATION OF THE PPP AUTOFOCUS METHOD IN PFA FOR SPOTLIGHT MODE SAR IMAGING 被引量:1
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作者 Fu Wenxian Hong Wen Li Shaohong (Dept. of Electronic Eng. Beijing Univ. of Aeronautics & Astronautics, Beijing 100083) 《Journal of Electronics(China)》 2002年第1期21-29,共9页
This paper first studies the phase errors for fine-resolution spotlight mode SAR imaging and decomposes the phase errors into two kinds, one is caused by translation and the other by rotation. Mathematical analysis an... This paper first studies the phase errors for fine-resolution spotlight mode SAR imaging and decomposes the phase errors into two kinds, one is caused by translation and the other by rotation. Mathematical analysis and computer simulations show the above mentioned motion kinds and their corresponding damages on spotlight mode SAR imaging. Based on this analysis, a single PPP is introduced for spotlight mode SAR imaging with the PFA on the assumption that relative rotation between APC and imaged scene is uniform. The selected single point is used first to correct the quadratic and higher order phase errors and then to adjust the linear errors. After this compensation, the space-invariant phase errors caused by translation are almost corrected. Finally results are presented with the simulated data. 展开更多
关键词 Spotlight mode SAR Phase error compensation PPP PFA
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Differential quadrature time element method for structural dynamics 被引量:3
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作者 Yu-Feng Xing Jing Guo 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2012年第3期782-792,共11页
An accurate and efficient differential quadrature time element method (DQTEM) is proposed for solving ordi- nary differential equations (ODEs), the numerical dissipation and dispersion of DQTEM is much smaller tha... An accurate and efficient differential quadrature time element method (DQTEM) is proposed for solving ordi- nary differential equations (ODEs), the numerical dissipation and dispersion of DQTEM is much smaller than that of the direct integration method of single/multi steps. Two methods of imposing initial conditions are given, which avoids the tediousness when derivative initial conditions are imposed, and the numerical comparisons indicate that the first method, in which the analog equations of initial displacements and velocities are used to directly replace the differential quadra- ture (DQ) analog equations of ODEs at the first and the last sampling points, respectively, is much more accurate than the second method, in which the DQ analog equations of initial conditions are used to directly replace the DQ analog equations of ODEs at the first two sampling points. On the contrary to the conventional step-by-step direct integration schemes, the solutions at all sampling points can be obtained simultaneously by DQTEM, and generally, one differential quadrature time element may be enough for the whole time domain. Extensive numerical comparisons validate the effi- ciency and accuracy of the proposed method. 展开更多
关键词 Differential quadrature rule Direct integrationmethod Time element Phase error. Artificial damping
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Crosstalk analysis of silicon-on-insulator nanowire-arrayed waveguide grating
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作者 李凯丽 安俊明 +6 位作者 张家顺 王玥 王亮亮 李建光 吴远大 尹小杰 胡雄伟 《Chinese Physics B》 SCIE EI CAS CSCD 2016年第12期294-299,共6页
The factors influencing the crosstalk of silicon-on-insulator (SO1) nanowire arrayed waveguide grating (AWG) are analyzed using the transfer function method. The analysis shows that wider and thicker arrayed waveg... The factors influencing the crosstalk of silicon-on-insulator (SO1) nanowire arrayed waveguide grating (AWG) are analyzed using the transfer function method. The analysis shows that wider and thicker arrayed waveguides, outsider fracture of arrayed waveguide, and larger channel space, could mitigate the deterioration of crosstalk. The SOI nanowire AWGs with different arrayed waveguide widths are fabricated by using deep ultraviolet lithography (DUV) and inductively coupled plasma etching (ICP) technology. The measurement results show that the crosstalk performance is improved by about 7 dB through adopting 800 nm arrayed waveguide width. 展开更多
关键词 SOI nanowire AWG CROSSTALK phase errors
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Research and implementation of continuous wave radar ranging method based on tri-frequency
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作者 袁其平 Fan Lijieare +2 位作者 Tong Zhengrong Yang Xiufeng Cao Ye 《High Technology Letters》 EI CAS 2014年第2期111-116,共6页
In the traditional dual-frequency radar ranging system,there is a contradiction between ranging precision and ranging distance.So a tri-frequency ranging method is proposed.The principle of the tri-frequency ranging i... In the traditional dual-frequency radar ranging system,there is a contradiction between ranging precision and ranging distance.So a tri-frequency ranging method is proposed.The principle of the tri-frequency ranging is that the distance can be achieved by transmitting the three frequencies and then measuring the three phase difference and calculating the number of wavelength.What's more,range ambiguity will not occur within a certain distance.The experimental results show that,if the waveband is 0.47 ~0.57 m,the measurement of unambiguous distance of 25 ~500m can be realized.If the wavelength tolerance error is less than ± 10^(-7) and the phase error is less than ± 10^(-3),the precision of the distance ranging can reach 10^(-6). 展开更多
关键词 tri-frequency RANGING SNR phase error wavelength error
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