基于负载转矩反馈的机械谐振抑制方法

柔性环节带来的机械谐振是制约伺服系统性能提升的一个关键问题。通过对伺服系统机械谐振的原理阐述,分析引起伺服系统机械谐振的两种原因。利用加速度反馈的方法可以等效增大电机惯量,从而抑制机械谐振。本文提出一种基于卡尔曼滤波器的惯量比可调负载转矩反馈方法,并通过确定最优惯量比进而计算得到负载转矩反馈系数。基于卡尔曼滤波器设计负载转矩观测器,再将观测到的负载转矩反馈到电流环给定中。通过matlab对观测器及负载转矩反馈抑制机械谐振效果进行仿真验证。     

基于陷波器的伺服系统共振抑制的研究

为了有效解决伺服系统中由于机械刚度低产生的机械共振,利用Matlab对伺服驱动模型进行仿真,借助FDAtool设计了2阶直接Ⅱ型陷波器,消除了伺服和负载组成的双惯性系统之间的共振频率.发现并分析了通带衰减参数对共振抑制的影响,在DSP上实现了双惯性系统的机械共振抑制控制程序,提出了陷波器在实时系统上的实现算法,并用永磁同步电机与丝杠进行实验验证,实验结果表明共振得到了抑制.     

基于高阶滑模和加速度反馈的机械谐振抑制方法

提出一种基于高阶滑模和加速度反馈的机械谐振抑制方法.针对永磁同步电机定子电流和电机转速分别设计了高阶滑模控制器.采用非奇异终端滑模面,使得定子电流在有限时间收敛.速度环引入加速度反馈,降低机械谐振的影响.仿真结果表明,与PI控制器分别结合陷波器以及加速度反馈的方法相比,所提方法可以有效抑制机械谐振,在保证动态响应性能的同时,增强了系统对于负载扰动的鲁棒性.     

滑模观测器在大惯量扫描镜系统中抗谐振的应用

针对扫描镜伺服控制系统中柔性连接所导致的机械谐振问题, 本文提出一种结合电机加速度反馈以及负 载速度反馈的滑模观测器控制方法. 首先建立伺服系统柔性连接的数学模型并分析谐振对系统性能的影响; 然后 给出滑模观测器的设计过程; 随后将观测出的电机加速度以及负载速度反馈到伺服系统中进行补偿; 最后分析了 位置传感器对伺服系统控制性能的影响, 系统的鲁棒性, 并与相似被控条件下的其他控制方法进行了比较. 仿真结 果表明: 与未采用观测器时相比, 本文所提出的方法有效地抑制了基于柔性连接的伺服系统中的机械谐振问题, 提 高了系统的控制性能, 且具有较高的鲁棒性.     

现代控制理论在大型精密雷达伺服系统中的应用

本文采用状态空间分析方法,运用现代控制理论中状态反馈、扰动补偿、状态观测器等基本结果,分析了大型双电机驱动的精密跟踪雷达伺服系统的差速振荡、传动机构谐振、负载力矩补偿等问题,从而为大型精密雷达伺服系统提供了一个新的设计方法。     

三轴稳定卫星扫描镜伺服系统的谐振抑制

本文针对三轴稳定卫星中的扫描镜伺服系统在运行时产生的机械谐振现象,采用在反馈回路中加入加速度观测器的方法抑制此类机械谐振.首先针对大惯量扫描镜伺服系统的机械传动结构建立研究模型,通过数学推导和仿真分析谐振产生的原因及谐振对系统控制性能的影响;然后采用加速度观测器方法,将观测出的加速度反馈到伺服系统电流环的前端对谐振进行补偿,并分析了噪声对观测器性能的影响与限制;最后的仿真结果表明,相比于采用陷波滤波器抑制谐振的方法,采用加速度观测器能更为有效地抑制三轴稳定卫星中扫描镜伺服控制系统中的机械谐振,并提高系统的控制性能,且设计的观测器对噪声具有良好的鲁棒性.     

大惯量扫描镜的滑模自抗扰控制

针对大惯量扫描镜伺服系统中因柔性连接所导致的机械谐振问题,本文提出一种非线性滑模自抗扰控制方法对机械谐振加以抑制.首先建立了伺服系统谐振数学模型,并分析了自抗扰控制抑制谐振的原理;然后建立了速度环滑模自抗扰控制器,并在计算机仿真软件中针对连续–离散混合模型进行仿真;最后在大惯量扫描镜机构上进行控制实验.仿真结果表明,采用滑模自抗扰控制后,机械谐振得到了抑制,系统的动态性能得到了提高,系统更接近于刚性连接系统.实验结果表明,扫描镜摆动过程中匀速段及反向加速段的机械谐振得到了有效抑制,位置跟踪精度得到了有效提高,达到了设计要求(<1′′).     

克服大型雷达伺服系统机械谐振的一种新设计方法及仿真

大型雷达伺服系统由于传动机构的弹性变形而产生机械谐振,按经典理论设计此类系统,机械谐振很难克服。本文提出了一种基于现代控制理论的全状态反馈及观测器理论的新的设计方案,并以某实际的大型雷达伺服系统进行了计算机仿真。结果表明,本文提出的方案是可行的,较好地克服了机械谐振,从而大大提高了系统的快速性和抗风扰能力。同时,这种方案容易实现,所需增添的设备很少。     

直线伺服同步传动的H∞控制

研究直线伺服系统位置同步传动的H∞控制问题,以2台直线电机作为高速度、高精度龙门移动式镗铣床的龙门柱纵向进给的传动机构为应用背景,提出一种同步传动H∞控制方案.该方案将同步传动的2台电机看作一个整体被控对象,由H∞反馈控制器保证同步精度.仿真结果表明了所提出方案的合理性和有效性.     

应用复杂陷波器精确消除经纬仪机械谐振方法的研究

为了精确消除机械谐振频率对经纬仪系统性能的影响,应用了复杂型的数字陷波器,利用其幅频特性与实际系统幅频特性相对比的方法,精确消除了机械谐振.实验表明:该方法可以做到在对经纬仪低频段特性影响较小的情况下,精确消除机械谐振,提高经纬仪的闭环带宽及其稳定性.     

An adaptive notch filter for suppressing mechanical resonance in high track density disk drives

In disk drive servo system, a notch filter is usually used to suppress mechanical resonance of an actuator. However, the resonance frequency differs from drive to drive due to manufacturing tolerance and varies with temperature even within a single drive. In this paper, we present an adaptive digital notch filter that can identify the resonance frequency of the actuator quickly and can adjust automatically its center frequency. For the fast identification of resonance frequency, a new estimation filter and its tuning algorithm are developed. Also, we give a rigorous analysis for the convergence of our tuning algorithm. We furthermore present some experimental results using a commercially available hard disk drive in order to demonstrate the practical use of our work.     

A multi‐stub loaded compact UWB BPF with a broad notch band and extended stopband characteristics

A compact ultrawideband (UWB) bandpass filter (BPF) employing the principle of multiple mode resonance characteristics to create UWB passband with high selectivity and simultaneously having extensive stopband characteristic is presented. Utilizing five stubs attached along with the asymmetric trisection stepped impedance resonator (ATSSIR), the proposed resonator enables seven transmission poles inside the passband. As an additional attributes the projected filter triggers one transmission zero at 5.0 GHz which helps to mitigate WLAN signal interference. No additional circuitry is used to generate a notch band. The proposed prototype of UWB BPF is fabricated and estimated. Simulated and estimated results are in great understanding. The prospective filter displays a deliberate passband from 2.9 to 11.02 GHz. The filter unveils deceptive free wide upper stop band attributes till 25 GHz with least attenuation of 10 dB all through the stop band.     

脑电信号中工频干扰去除的综合研究

微弱的脑电信号中常混有工频干扰,严重影响到有用的脑电信号提取和分析。针对传统陷波器会削弱有用的脑电信号的缺陷,文中研究了三种稳健算法:基于零极点分布原理的陷波器、自适应滤波器以及独立成分分析算法,来抑制脑电信号中的工频干扰。仿真实验结果表明,三种算法都可以成功去除脑电信号中的工频干扰成分,并且较传统陷波器对工频附近频谱影响更小,从而有效地克服了传统陷波器的缺陷;此外,独立成分分析算法能更好地保留有用的脑电信息,具有更大的优越性。另外,三种算法都可以应用于其他需要陷波的场合,具有很好的扩展性。     

Detection and reduction of middle frequency resonance for an industrial servo

This work proposes a novel strategy for middle frequency resonance detection and reduction for the speed control of industrial servo systems. The report includes an analysis of the drawbacks of the traditional resonance reduction method based on an adaptive notch filter in the middle frequency range, and the main drawback is summarized as the difference between the resonance frequency and the oscillation frequency. In the proposed method, a self-tuning low-pass filter with a corner frequency determined using FFT results and several self-tuning rules is introduced in the speed feedback path. Consequently, the effective range of the adaptive filter is extended across the middle frequency range. The simulation and experimental results show that the frequency detection is accurate, and the resonances are successfully reduced during steady-state and dynamic speeds.     

Compact ultra‐wideband bandpass filter with variable notch characteristics based on transversal signal‐interaction concepts

A novel technique is presented to design highly compact microstrip ultra‐wideband (UWB) bandpass filters that exhibit high selectivity quasi‐elliptical response. The design is based on transversal signal‐interaction concepts that enable the inclusion of single or dual notch‐bands within the filter's passband to eliminate interference from other services that coexist within the UWB spectrum. The filter configuration comprises of two transmission paths which include folded T‐shaped stepped impedance resonators (SIRs) that are capacitively coupled with the input/output lines to enable signal transmission. It is shown that by combining the filters of different passband centre frequencies an UWB filter can be realised with either a single‐ or dual‐notch function. The theoretical performance of the filter is corroborated via measurements to confirm that the proposed filter exhibits UWB passband of 123% for a 3 dB fractional bandwidth, a flat group‐delay with maximum variation of less than 0.3 ns, passband insertion loss less than 0.94 dB, high selectivity, a sharp rejection notch‐band with attenuation of ?23 dB, and a good overall out‐of‐band performance. Furthermore, the filter occupies a significantly small area of 94 mm² compared with its classical counterparts. © 2014 Wiley Periodicals, Inc. Int J RF and Microwave CAE 24:549–559, 2014.     

基于复交替投影神经网络的陷波器

针对军事上经常遇到的一种特定情况，在综合考虑信号的时域与频域特征的基础上，运用复交替投影神经网络的结论，设计出了一种基于复交替投影神经网络的陷波器。理论分析与仿真结果表明，该陷波器对强的工频干扰的基频及其高次谐波都有一定的抑制作用，而且还能跟踪工频干扰的变化。尽管是针对特定情况设计的，它对其它情况也是适用的。由于采用全互连神经网络结构，而且各神经元的运算都极为简单，因而易于并行计算和VLSI实现，从而可满足军事上高实时性的要求。     

Notch filter feedback control in a class of chaotic systems

The paper focuses on the problem of the notch filter feedback control in the perturbed planar Hamiltonian systems. By Melnikov's method, a suitable range of parameters in the notch filter controller can be obtained to convert chaotic motions into desired low-period motions. The averaging method is introduced to analyze the stability of the low-period orbits, the subharmonic orbits inside the homoclinic loop, in the control systems. As a typical example, the design procedure for controlling Duffing's oscillator and its stability analysis are derived in detail, and the thorough simulation results are presented to demonstrate the effectiveness of the theoretical analysis. Finally, the further examples show the applicability of the notch filter controller in a wide range of chaotic systems and hyper-chaotic systems.     

有源电力滤波器谐波检测的新型SRF-PLL设计研究

针对有源电力滤波器中基于同步坐标系的锁相环(synchronous reference frame PLL,SRF-PLL)在三相电网电压不平衡且有畸变时,负序基频分量和高频谐波电流对SRF-PLL的影响。文章采用在基于同步坐标系的锁相环中加入自适应陷波器(adaptive notch filter,ANF)和自适应滤波器(adaptive filter)的技术。利用自适应陷波器的两个相互正交的输出量抵消同频负序分量导致的2倍工频波动,并采用自适应滤波器的最小均方算法(Least Mean Square,LMS)滤除高频谐波分量,从而准确的提取基波电压的幅值与相位。文章以单独加入自适应滤波器或自适应陷波器作比较,通过仿真分析验证文中方法能更加准确的提取电网电压频率,正余弦函数曲线更加平滑,具有良好的动态性能和稳定性。     

用于消除谐波干扰的Ｖ型滤波器的零极点配置设计方法

针对某设备振动模态测试中,市电对测试信息产生的５０Ｈz工频及其谐波干扰,设计了阻带带宽极狭窄（小于１Ｈz）的Ｖ型数字带虎波器,并完成了相应的数字滤波,Ｖ型数字滤波器物理意义清晰,设计和实现方法简单灵活,效果大大优于某些消除谐波干扰的算法,本文介绍了该Ｖ型滤波器的设计及实现方法。