The electro-hydraulic servo system was studied to cancel the amplitude attenuation and phase delay of its sinusoidal response,by developing a network using normalized least-mean-square (LMS) adaptive filtering algorit...The electro-hydraulic servo system was studied to cancel the amplitude attenuation and phase delay of its sinusoidal response,by developing a network using normalized least-mean-square (LMS) adaptive filtering algorithm.The command input was corrected by weights to generate the desired input for the algorithm,and the feedback was brought into the feedback correction,whose output was the weighted feedback.The weights of the normalized LMS adaptive filtering algorithm were updated on-line according to the estimation error between the desired input and the weighted feedback.Thus,the updated weights were copied to the input correction.The estimation error was forced to zero by the normalized LMS adaptive filtering algorithm such that the weighted feedback was equal to the desired input,making the feedback track the command.The above concept was used as a basis for the development of amplitude phase control.The method has good real-time performance without estimating the system model.The simulation and experiment results show that the proposed amplitude phase control can efficiently cancel the amplitude attenuation and phase delay with high precision.展开更多
Space-time adaptive processing（STAP） has been proven to be one of the best techniques capable of detecting weak moving targets in strong clutter environment and has been widely applied in airborne ground moving targ...Space-time adaptive processing（STAP） has been proven to be one of the best techniques capable of detecting weak moving targets in strong clutter environment and has been widely applied in airborne ground moving target indication（GMTI） radar.This paper applies an amplitude and phase estimation（APES） approach to two aspects of the STAP algorithm.Firstly,APES is applied to accurately describe the clutter characteristic in angle-Doppler domain.Then,APES is incorporated into the standard STAP algorithm to improve its performance without increasing transmitting/receiving channel and pulse number.The experimental examples show that the detection performance can be improved by using the APES technique,as well as the high computational complexity can be avoided.展开更多
多输入多输出(MIMO,Multiple-Input Multiple-Output)雷达用多个发射天线同时发射多个独立信号照射目标,并使用多个接收天线接收目标回波信号.本文研究了MIMO雷达中参数估计的稳健性问题.本文应用幅度相位估计(APES,Amplitude and Phase...多输入多输出(MIMO,Multiple-Input Multiple-Output)雷达用多个发射天线同时发射多个独立信号照射目标,并使用多个接收天线接收目标回波信号.本文研究了MIMO雷达中参数估计的稳健性问题.本文应用幅度相位估计(APES,Amplitude and Phase EStimation)技术,利用目标的方位角最大似然估计值,得到了衰落向量的APES估计算法.考虑到方位角估计的不准确性,借鉴稳健的Capon波束形成器的设计思想,本文推导了衰落向量的稳健的APES估计算法.仿真实验表明,衰落向量的APES算法与稳健的APES算法性能十分接近.因此,衰落向量的APES估计算法是稳健的.展开更多
结合干涉雷达的天线结构和二维波达方向(direction of arrival,DOA)估计方法,提出一种基于二维干涉式幅相估计的分布式相参阵盲DOA估计算法。利用二维干涉式幅相估计算法的空间谱和模型阶数选择准则获得目标个数和目标方向余弦的粗估计...结合干涉雷达的天线结构和二维波达方向(direction of arrival,DOA)估计方法,提出一种基于二维干涉式幅相估计的分布式相参阵盲DOA估计算法。利用二维干涉式幅相估计算法的空间谱和模型阶数选择准则获得目标个数和目标方向余弦的粗估计;使用子阵间的相位中心偏移来获得目标方向余弦的精估计;针对分布孔径带来的测角模糊问题,采用双尺度解模糊算法实现分布式阵列的高精度方向估计。仿真结果验证了分布式相参阵的高精度测角性能及所提算法的有效性,也验证了分布阵DOA估计中存在基线模糊门限。展开更多
相控阵列天线的各收发通道幅相误差会对其性能产生较大影响。在分析相控阵列天线幅相误差的产生原因的基础上,提出了一种幅相误差外、内校准结合方法,其中外校准方法基于(Multiple Signal Classification,MUSIC)算法引入模拟退火算法对...相控阵列天线的各收发通道幅相误差会对其性能产生较大影响。在分析相控阵列天线幅相误差的产生原因的基础上,提出了一种幅相误差外、内校准结合方法,其中外校准方法基于(Multiple Signal Classification,MUSIC)算法引入模拟退火算法对互耦矩阵和阵元位置扰动进行联合估计,可补偿加工制造安装公差及天线阵元间的互耦导致的幅相误差,内校准方法可补偿天线工作环境变化、器件老化等因素导致的幅相误差。计算机仿真结果表明了方法的有效性。展开更多
为了获得高精度的多输入多输出(multiple-input multiple-output,MIMO)雷达的目标角度估计和幅度估计,本文基于幅度相位估计(amplitude and phase estimation,APES)算法和广义似然比检验(generalized-likelihood ratio test,GLRT)算法,...为了获得高精度的多输入多输出(multiple-input multiple-output,MIMO)雷达的目标角度估计和幅度估计,本文基于幅度相位估计(amplitude and phase estimation,APES)算法和广义似然比检验(generalized-likelihood ratio test,GLRT)算法,提出了一种使用似然比的相位幅度估计(GAPES)新算法。在接收端通过GLRT算法估计出目标角度,然后用APES算法修正幅度,实现了在强干扰环境下提高角度和幅度分辨率。仿真结果表明了该算法的有效性。展开更多
The variable structure control （VSC） theory is applied to the electro-hydraulic servo system here. The VSC control law is achieved using Lyapunov method and pole placement. To eliminate the chattering phenomena, a s...The variable structure control （VSC） theory is applied to the electro-hydraulic servo system here. The VSC control law is achieved using Lyapunov method and pole placement. To eliminate the chattering phenomena, a saturation function is adopted. The proposed VSC approach is fairly robust to load disturbance and system parameter variation. Since the distortion. including phase lag and amplitude attenuation occurs in the system sinusoid response, the amplitude and phase control （APC） algorithm, based on Adaline neural network and using LMS algorithm, is developed for distortion cancellation. The APC controller is simple and can on-line adjust, thus it gives accurate tracking.展开更多
针对传统幅度与相位估计(Amplitude and phase estimation,APES)算法难以应用于非均匀阵列的问题,研究了基于矢量水听器的APES算法。利用矢量水听器能够同时共点测量声压和质点振速的特点,将矢量水听器的声压和解析振速通道作为两个子阵...针对传统幅度与相位估计(Amplitude and phase estimation,APES)算法难以应用于非均匀阵列的问题,研究了基于矢量水听器的APES算法。利用矢量水听器能够同时共点测量声压和质点振速的特点,将矢量水听器的声压和解析振速通道作为两个子阵,两路子阵之间只存在一个相位差,且与阵元位置无关,使得APES算法能够应用于任意形状的阵列。推导和分析了矢量APES算法的阵增益及其稳健性。分析和仿真表明:该方法相比于传统APES算法,具有更高的阵增益,且能适用于非均匀阵列;相比于最小方差无失真响应(Minimum variance distortionless response,MVDR)算法,具有更好的稳健性,能解决相干问题及能够获得更准确的信号功率,并用实测数据验证了算法的有效性。展开更多
A new beam broadening synthesis technique for Synthetic Aperture Radar(SAR) antenna array, namely Projection Matrix Algorithm(PMA) is presented. The theory of PMA is introduced firstly, and then the iterative renewed ...A new beam broadening synthesis technique for Synthetic Aperture Radar(SAR) antenna array, namely Projection Matrix Algorithm(PMA) is presented. The theory of PMA is introduced firstly, and then the iterative renewed manner is improved to resolve the unbalance problem under amplitude and phase control. In order to validate the algorithm correct and effective, an actual engineering application example is investigated. The beam synthesis results of 1.0~4.5 times broadening under the phase only control and the amplitude and phase control using improved PMA are given. The results show that the beam directivity, the beam broadening, and the side-lobe level requirements were met. It is demonstrated that the improved PMA was effective and feasible for SAR application.展开更多
电力系统的瞬时性故障易产生暂态衰减直流分量DDC(decaying DC component)、高次谐波等干扰信号,有效滤除干扰信号以实现电压基波幅值相位的快速、准确检测,对于提升电能质量非常重要。为此,基于三相畸变电压信号的周期性和半波对称性,...电力系统的瞬时性故障易产生暂态衰减直流分量DDC(decaying DC component)、高次谐波等干扰信号,有效滤除干扰信号以实现电压基波幅值相位的快速、准确检测,对于提升电能质量非常重要。为此,基于三相畸变电压信号的周期性和半波对称性,提出在abc坐标系下对畸变电压分别延迟半周期、全周期采样,实现DDC分量的单位周期检测。其次,针对同时含有DDC与高次谐波的畸变信号,在dq旋转坐标系下将DDC检测算法与滑动平均滤波算法结合,实现单位周期同时滤除DDC与高次谐波分量。最后,将所提检测算法与电压相位开环算法结合,通过搭建RT-LAB半实物实时仿真平台对基波电压幅值相位进行检测验证。实验结果表明:在dq坐标系下同时滤除DDC与高次谐波干扰信号的检测算法响应时间仅为20 ms,验证了所提算法的有效性以及分析结论的正确性。展开更多
基金Project(50905037) supported by the National Natural Science Foundation of ChinaProject(20092304120014) supported by Specialized Research Fund for the Doctoral Program of Higher Education of China+2 种基金 Project(20100471021) supported by the China Postdoctoral Science Foundation Project(LBH-Q09134) supported by Heilongjiang Postdoctoral Science-Research Foundation,China Project (HEUFT09013) supported by the Foundation of Harbin Engineering University,China
文摘The electro-hydraulic servo system was studied to cancel the amplitude attenuation and phase delay of its sinusoidal response,by developing a network using normalized least-mean-square (LMS) adaptive filtering algorithm.The command input was corrected by weights to generate the desired input for the algorithm,and the feedback was brought into the feedback correction,whose output was the weighted feedback.The weights of the normalized LMS adaptive filtering algorithm were updated on-line according to the estimation error between the desired input and the weighted feedback.Thus,the updated weights were copied to the input correction.The estimation error was forced to zero by the normalized LMS adaptive filtering algorithm such that the weighted feedback was equal to the desired input,making the feedback track the command.The above concept was used as a basis for the development of amplitude phase control.The method has good real-time performance without estimating the system model.The simulation and experiment results show that the proposed amplitude phase control can efficiently cancel the amplitude attenuation and phase delay with high precision.
文摘Space-time adaptive processing（STAP） has been proven to be one of the best techniques capable of detecting weak moving targets in strong clutter environment and has been widely applied in airborne ground moving target indication（GMTI） radar.This paper applies an amplitude and phase estimation（APES） approach to two aspects of the STAP algorithm.Firstly,APES is applied to accurately describe the clutter characteristic in angle-Doppler domain.Then,APES is incorporated into the standard STAP algorithm to improve its performance without increasing transmitting/receiving channel and pulse number.The experimental examples show that the detection performance can be improved by using the APES technique,as well as the high computational complexity can be avoided.
文摘多输入多输出(MIMO,Multiple-Input Multiple-Output)雷达用多个发射天线同时发射多个独立信号照射目标,并使用多个接收天线接收目标回波信号.本文研究了MIMO雷达中参数估计的稳健性问题.本文应用幅度相位估计(APES,Amplitude and Phase EStimation)技术,利用目标的方位角最大似然估计值,得到了衰落向量的APES估计算法.考虑到方位角估计的不准确性,借鉴稳健的Capon波束形成器的设计思想,本文推导了衰落向量的稳健的APES估计算法.仿真实验表明,衰落向量的APES算法与稳健的APES算法性能十分接近.因此,衰落向量的APES估计算法是稳健的.
文摘结合干涉雷达的天线结构和二维波达方向(direction of arrival,DOA)估计方法,提出一种基于二维干涉式幅相估计的分布式相参阵盲DOA估计算法。利用二维干涉式幅相估计算法的空间谱和模型阶数选择准则获得目标个数和目标方向余弦的粗估计;使用子阵间的相位中心偏移来获得目标方向余弦的精估计;针对分布孔径带来的测角模糊问题,采用双尺度解模糊算法实现分布式阵列的高精度方向估计。仿真结果验证了分布式相参阵的高精度测角性能及所提算法的有效性,也验证了分布阵DOA估计中存在基线模糊门限。
文摘相控阵列天线的各收发通道幅相误差会对其性能产生较大影响。在分析相控阵列天线幅相误差的产生原因的基础上,提出了一种幅相误差外、内校准结合方法,其中外校准方法基于(Multiple Signal Classification,MUSIC)算法引入模拟退火算法对互耦矩阵和阵元位置扰动进行联合估计,可补偿加工制造安装公差及天线阵元间的互耦导致的幅相误差,内校准方法可补偿天线工作环境变化、器件老化等因素导致的幅相误差。计算机仿真结果表明了方法的有效性。
文摘为了获得高精度的多输入多输出(multiple-input multiple-output,MIMO)雷达的目标角度估计和幅度估计,本文基于幅度相位估计(amplitude and phase estimation,APES)算法和广义似然比检验(generalized-likelihood ratio test,GLRT)算法,提出了一种使用似然比的相位幅度估计(GAPES)新算法。在接收端通过GLRT算法估计出目标角度,然后用APES算法修正幅度,实现了在强干扰环境下提高角度和幅度分辨率。仿真结果表明了该算法的有效性。
文摘The variable structure control （VSC） theory is applied to the electro-hydraulic servo system here. The VSC control law is achieved using Lyapunov method and pole placement. To eliminate the chattering phenomena, a saturation function is adopted. The proposed VSC approach is fairly robust to load disturbance and system parameter variation. Since the distortion. including phase lag and amplitude attenuation occurs in the system sinusoid response, the amplitude and phase control （APC） algorithm, based on Adaline neural network and using LMS algorithm, is developed for distortion cancellation. The APC controller is simple and can on-line adjust, thus it gives accurate tracking.
文摘A new beam broadening synthesis technique for Synthetic Aperture Radar(SAR) antenna array, namely Projection Matrix Algorithm(PMA) is presented. The theory of PMA is introduced firstly, and then the iterative renewed manner is improved to resolve the unbalance problem under amplitude and phase control. In order to validate the algorithm correct and effective, an actual engineering application example is investigated. The beam synthesis results of 1.0~4.5 times broadening under the phase only control and the amplitude and phase control using improved PMA are given. The results show that the beam directivity, the beam broadening, and the side-lobe level requirements were met. It is demonstrated that the improved PMA was effective and feasible for SAR application.
文摘电力系统的瞬时性故障易产生暂态衰减直流分量DDC(decaying DC component)、高次谐波等干扰信号,有效滤除干扰信号以实现电压基波幅值相位的快速、准确检测,对于提升电能质量非常重要。为此,基于三相畸变电压信号的周期性和半波对称性,提出在abc坐标系下对畸变电压分别延迟半周期、全周期采样,实现DDC分量的单位周期检测。其次,针对同时含有DDC与高次谐波的畸变信号,在dq旋转坐标系下将DDC检测算法与滑动平均滤波算法结合,实现单位周期同时滤除DDC与高次谐波分量。最后,将所提检测算法与电压相位开环算法结合,通过搭建RT-LAB半实物实时仿真平台对基波电压幅值相位进行检测验证。实验结果表明:在dq坐标系下同时滤除DDC与高次谐波干扰信号的检测算法响应时间仅为20 ms,验证了所提算法的有效性以及分析结论的正确性。
