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数字通信链路的Simulink仿真和干扰效果评估 被引量:1
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作者 吴玲玲 《舰船电子对抗》 2014年第1期62-64,77,共4页
对于干扰而言,选择干扰体制和设置合适的干扰参数一直是通信对抗的重点。客观、准确、定量地分析和评价对抗装备对数字通信链路的干扰效果对于提高干扰和抗干扰能力具有重要意义。仿真了对常用数字通信链路信号的干扰效果评估,采用的干... 对于干扰而言,选择干扰体制和设置合适的干扰参数一直是通信对抗的重点。客观、准确、定量地分析和评价对抗装备对数字通信链路的干扰效果对于提高干扰和抗干扰能力具有重要意义。仿真了对常用数字通信链路信号的干扰效果评估,采用的干扰样式有单音干扰、相关干扰、同步扰动干扰等,对各种干扰的干扰效果进行评估和比较,为优化干扰样式提供了基础。 展开更多
关键词 单音干扰 相关干扰 同步扰动干扰
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零陷优化的稳健波束形成算法 被引量:1
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作者 李帅 王铮 杨小鹏 《信号处理》 CSCD 北大核心 2017年第12期1542-1547,共6页
传统的自适应波束形成算法在干扰方向出现扰动且期望信号导向矢量失配时,不仅无法持续有效地抑制干扰,而且会在期望信号方向产生零陷致使期望信号相消,算法性能严重下降。针对该问题,本文提出了一种零陷优化的稳健波束形成算法。该算法... 传统的自适应波束形成算法在干扰方向出现扰动且期望信号导向矢量失配时,不仅无法持续有效地抑制干扰,而且会在期望信号方向产生零陷致使期望信号相消,算法性能严重下降。针对该问题,本文提出了一种零陷优化的稳健波束形成算法。该算法首先通过干扰导向矢量的左右旋转来展宽零陷,接着将采样数据向干扰子空间投影,并对干扰分量进行加权处理以增强采样数据中的干扰强度,加深干扰零陷,最后采用导向矢量不确定集约束算法保证期望信号的接收增益。计算机仿真结果表明:该算法能够有效展宽干扰零陷,并能够保证期望信号增益,具有较好的稳健性。 展开更多
关键词 自适应波束形成 干扰扰动 导向矢量失配 零陷优化 导向矢量不确定集约束
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增量式编码器抗抖性研究 被引量:10
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作者 张九才 王文祥 +1 位作者 杨显志 孙嘉鸿 《自动化仪表》 CAS 2005年第10期38-39,共2页
在分析了常见的3种增量型编码器数据采集方法的基础上,设计了一种新型编码器数据采集电路,提出了一种抗扰动的算法,利用该编码器数据采集电路和算法实现了增量型编码器数据采集。该算法消除了抖动,提高了计数器的最高计数频率。若采用C... 在分析了常见的3种增量型编码器数据采集方法的基础上,设计了一种新型编码器数据采集电路,提出了一种抗扰动的算法,利用该编码器数据采集电路和算法实现了增量型编码器数据采集。该算法消除了抖动,提高了计数器的最高计数频率。若采用CPLD设计硬件电路,可以实现高速度、高精度增量型编码器的数据采集。 展开更多
关键词 增量型编码器 数据采集 扰动干扰 传感器 增量式编码器 数据采集方法 增量型编码器 数据采集电路 CPLD设计 算法实现 硬件电路 计数频率 扰动
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螺旋桨负载平衡装置控制系统设计及仿真
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作者 饶博文 唐猛 代登志 《计算机测量与控制》 2018年第6期61-64,68,共5页
以一螺旋桨负载平衡装置为研究对象,通过对该装置在俯仰及偏转位置角度的控制,以达到对该装置方位控制和负载力平衡的目标;基于该系统强的耦合特性,通过状态反馈策略实现对系统解耦,并结合位置控制,实现该装置方位和俯仰角度的精确控制... 以一螺旋桨负载平衡装置为研究对象,通过对该装置在俯仰及偏转位置角度的控制,以达到对该装置方位控制和负载力平衡的目标;基于该系统强的耦合特性,通过状态反馈策略实现对系统解耦,并结合位置控制,实现该装置方位和俯仰角度的精确控制;同时,为了应对负载突变扰动对该装置位置及姿态影响,一个干扰观测器被设计出以用于实时观测外部干扰推力大小,最后,通过前馈补偿的方式提高该装置对干扰抑制的响应效果;通过系统动态模型建立、解耦设计、位置控制设计、扰动观察器设计和基于该观察输出的前馈干扰抑制补偿设计等研究,实现了当外载荷突变时的扰动抑制及姿态控制;研究结果表明引入干扰观测器及前馈补偿调节控制器时的扰动抑制能力得以增强;这对于基于该装置的平台的稳定性提高有着极大的工程应用价值。 展开更多
关键词 螺旋桨负载平衡装置 解耦控制 干扰扰动 降阶观测器
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四旋翼无人机双螺旋桨推进跟踪最优控制仿真 被引量:1
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作者 吴米 张世亮 吴佳 《计算机仿真》 北大核心 2018年第10期109-113,共5页
双螺旋桨推进跟踪系统在四旋翼无人机悬吊的动态环境中,要求根据上位机实时控制指令调整空间位置,保证双螺旋桨推进系统在空间中始终保持精准的位置输出。如何降低外界的随机扰动对系统的影响,同时保证系统的动态跟随性能是设计的一大... 双螺旋桨推进跟踪系统在四旋翼无人机悬吊的动态环境中,要求根据上位机实时控制指令调整空间位置,保证双螺旋桨推进系统在空间中始终保持精准的位置输出。如何降低外界的随机扰动对系统的影响,同时保证系统的动态跟随性能是设计的一大难点。为了解决上述问题,提出了一种利用干扰观测的最优控制器方法。采用极点配置法设计干扰推力观测器实时观测出外部干扰推力。通过前馈补偿的方式降低干扰推力对系统的影响。为了平衡系统误差和输入的控制量,设计最优控制器来保证整体反馈系统的鲁棒稳定性。通过对设计的控制器进行仿真验证,表明优化后的系统受到扰动时有更小的超调和恢复时间,说明带有干扰观测器的最优控制器能够有效地补偿外部扰动,提高推进系统的位置响应精度及抗干扰能力。 展开更多
关键词 螺旋桨推进系统 最优控制 干扰扰动 降阶观测器
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A new PMSM speed modulation system with sliding mode based on active-disturbance-rejection control 被引量:12
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作者 荣智林 黄庆 《Journal of Central South University》 SCIE EI CAS CSCD 2016年第6期1406-1415,共10页
A sliding mode and active disturbance rejection control(SM-ADRC)was employed to regulate the speed of a permanent magnet synchronous motor(PMSM).The major advantages of the proposed control scheme are that it can main... A sliding mode and active disturbance rejection control(SM-ADRC)was employed to regulate the speed of a permanent magnet synchronous motor(PMSM).The major advantages of the proposed control scheme are that it can maintain the original features of ADRC and make the parameters of ADRC transition smoothly.The proposed control scheme also ensures speed control accuracy and improves the robustness and anti-load disturbance ability of the system.Moreover,through the analysis of a d-axis current output equation,a novel current-loop SM-ADRC is presented to improve the system’s dynamic performance and inner ability of anti-load disturbance.Results of a simulation and experiments show that the improved sliding-mode ADRC system has the advantages of fast response,small overshoot,small steady-state error,wide speed range and high control accuracy.It shows that the system has strong anti-interference ability to reduce the influence of variations in rotational inertia,load and internal parameters. 展开更多
关键词 disturbance rejection auto tuning permanent magnet synchronous motor speed modulation system
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Disturbance rejection control for Raymond mill grinding system based on disturbance observer
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作者 牛丹 陈夕松 +1 位作者 杨俊 周杏鹏 《Journal of Central South University》 SCIE EI CAS CSCD 2017年第9期2019-2027,共9页
In the Raymond mill grinding processes,high-accuracy control for the current of Raymond mill is vital to enhance the product quality and production efficiency as well as cut down the consumption of spare parts.However... In the Raymond mill grinding processes,high-accuracy control for the current of Raymond mill is vital to enhance the product quality and production efficiency as well as cut down the consumption of spare parts.However,strong external disturbances,such as variations of ore hardness and ore size,always exist.It is not easy to make the current of Raymond mill constant due to these strong disturbances.Several control strategies have been proposed to control the grinding processes.However,most of them(such as PID and MPC)reject disturbances merely through feedback regulation and do not deal with the disturbances directly,which may lead to poor control performance when strong disturbances occur.To improve disturbance rejection performance,a control scheme based on PI and disturbance observer is proposed in this work.The scheme combines a feedforward compensation part based on disturbance observer and a feedback regulation part using PI.The test results illustrate that the proposed method can obtain remarkable superiority in disturbance rejection compared with PI method in the Raymond mill grinding processes. 展开更多
关键词 disturbance observer proportional integral-disturbance observer (PI-DOB) disturbance rejection Raymond mill grinding process
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Nonlinear interaction mechanisms of disturbances in supersonic flat-plate boundary layers 被引量:3
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作者 YU Min LUO JiSheng 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2014年第11期2141-2151,共11页
Due to the complexity of compressible flows,nonlinear hydrodynamic stability theories in supersonic boundary layers are not sufficient.In order to reveal the nonlinear interaction mechanisms of the rapidly amplified 3... Due to the complexity of compressible flows,nonlinear hydrodynamic stability theories in supersonic boundary layers are not sufficient.In order to reveal the nonlinear interaction mechanisms of the rapidly amplified 3-D disturbances in supersonic boundary layers at high Mach numbers,the nonlinear evolutions of different disturbances in flat-plate boundary layers at Mach number 4.5,6 and 8 are analyzed by numerical simulations.It can be concluded that the 3-D disturbances are amplified rapidly when the amplitude of the 2-D disturbance reaches a certain level.The most rapidly amplified 3-D disturbances are Klebanoff type(K-type)disturbances which have the same frequency as the 2-D disturbance.Among these K-type 3-D disturbances,the disturbances located at the junction of upper branch and lower branch of the neutral curve are amplified higher.Through analyzing the relationship between the amplification rate and the spanwise wavenumber of the 3-D disturbances at different evolution stages,the mechanism of the spanwise wavenumber selectivity of K-type 3-D disturbances in the presence of a finite amplitude 2-D disturbance is explained. 展开更多
关键词 disturbance supersonic junction branch introducing selectivity compressible hydrodynamic explained infinity
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TESTING INEQUALITY CONSTRAINTS IN A LINEAR REGRESSION MODEL WITH SPHERICALLY SYMMETRIC DISTURBANCES 被引量:1
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作者 ZHU Rong ZHOU Sherry Z F 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2014年第6期1204-1212,共9页
This paper develops a Wald statistic for testing the validity of multivariate inequality constraints in linear regression models with spherically symmetric disturbances,and derive the distributions of the test statist... This paper develops a Wald statistic for testing the validity of multivariate inequality constraints in linear regression models with spherically symmetric disturbances,and derive the distributions of the test statistic under null and nonnull hypotheses.The power of the test is then discussed.Numerical evaluations are also carried out to examine the power performances of the test for the case in which errors follow a multivariate student-t(Mt) distribution. 展开更多
关键词 Inequality constraint spherically symmetric distribution Wald test.
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Mechanism of perturbation-combined active control technique for asymmetric vortex flow over slender body at high angle of attack 被引量:1
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作者 WANG YanKui SHAN JiXiang +3 位作者 TIAN Wei DENG XueYing DONG JinGang TIAN Xiao 《Science China(Technological Sciences)》 SCIE EI CAS 2011年第10期2665-2673,共9页
Based on the determinability of asymmetric vortices flow over slender body under changeless round grain at high angle of attack,the effect of microblowing set in special position on the behaviors of asymmetric flow is... Based on the determinability of asymmetric vortices flow over slender body under changeless round grain at high angle of attack,the effect of microblowing set in special position on the behaviors of asymmetric flow is discussed in this paper,including blowing momentum and circumferential locations of the microblowing hole of 0.5 mm in diameter on nose tip.A new kind of active control technique,named perturbation-combined active control technique,which combines the micro-grain and micro-blowing perturbation,was proposed on the basis of the above.This control technique can not only change the sign of side force of slender body arbitrarily through changing the vortices positions between yaw-left and yaw-right configuration,but also can make the magnitude of side force variable gradually even at bistable state of asymmetric vortex.Finally,the interferential mechanism of the perturbation-combined active control technique has also been concluded from this paper.The tests have been conducted at low speed wind tunnel with subcritical Reynolds number of 1.05×10~5 at angle of attack α=50° in Beihang University,Beijing,China. 展开更多
关键词 asymmetric vortex perturbation-combined active flow control high angle of attack aerodynamics slender body
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Dynamics of a stochastic predator-prey model with mutual interference
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作者 Kai Wang Yanling Zhu 《International Journal of Biomathematics》 2014年第3期51-72,共22页
In this paper, a stochastic predator-prey (PP) model with mutual interference is considered. Some sufficient conditions for the existence of globally positive solution, non- persistence in the mean, weak persistence... In this paper, a stochastic predator-prey (PP) model with mutual interference is considered. Some sufficient conditions for the existence of globally positive solution, non- persistence in the mean, weak persistence in the mean, strong persistence in the mean and almost surely extinction of the the model are established. Moreover, the thresh- old between weak persistence in the mean and almost surely extinction of the prey is obtained. Some examples are given to show the feasibility of the results by numeri- cal simulation. It is significant that such a model is firstly proposed with stochastic perturbation. 展开更多
关键词 Stochastic predator-prey model Brownian motion pathwise estimation PERSISTENCE extinction.
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Dynamic analysis of a stage-structured predator-prey system with disturbed time delay and birth pulse
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作者 Weihua Wang Zuoliang Xiong Fang Wang 《International Journal of Biomathematics》 2014年第4期35-50,共16页
In this paper, a stage-structured predator prey system with birth pulse and disturbed time delay is investigated. The conditions of the prey-extinction periodic solution of the system which are globally attractive hav... In this paper, a stage-structured predator prey system with birth pulse and disturbed time delay is investigated. The conditions of the prey-extinction periodic solution of the system which are globally attractive have been obtained. Furthermore, the sufficient corlditions for the permanence of the system are established. Finally, numerical analysis is given to confirm the theoretical results. 展开更多
关键词 Birth pulse disturbed time delay STAGE-STRUCTURE prey-predator model.
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