AHODFC在交流调速中的应用及其软件实现

基于提取微分信号在工业控制及航天控制中的重要作用,介绍了一种可提取高品质微分信号的自适应高阶微分反馈控制器(AHODFC),并将其应用于交流调速系统中。考虑到在工程应用中,VC++易于实现交互界面、数据采集和端口操作等操作,基于VC++平台编制了该调速系统的控制界面,并介绍了高阶微分控制器算法的编程过程,还详细介绍了该调速系统的控制界面操作。通过仿真运行和实际系统的运行,证明高阶微分反馈控制与PID控制相比,具有控制效果好,参数调节容易,鲁棒性能好等特点,具有可行性及实用价值。     

微分器因过封度太小而引起误动作的解决方法

对微分器因过封度太小而引起误动作的现象分析及解决方法。     

Design and implementation of fractional differentiators,Part I: System based methods

The online calculation of fractional derivative is an important technique used in the control engineering area. To achieve satisfactory computing performance, this paper proposes a useful and effective tool named fractional order tracking differentiator (FOTD), which is easy to be implemented. A constructive method for designing the FOTD is developed using a class of asymptotically stable fractional order systems. It is shown that FOTD is the pioneering one to achieve it with simple structure, convenient construction and predominant performance. Finally, several examples are conducted to illustrate the effectiveness and efficiency of the proposed methods.     

Design of IIR fullband differentiators using parallel all-pass structure

A new approach for the design of recursive fullband digital differentiators using parallel all-pass structure is discussed in this paper. While magnitude response of designed fullband differentiator approximates the ideal one in the weighted Chebyshev sense, its phase response is a nearly-linear function of frequency at low frequencies. The low-pass differentiators, presented in this paper, are obtained by cascading the proposed recursive fullband differentiators with the corresponding low-pass filters. The phase response linearity error of such low-pass differentiators is shown to be primarily affected by the phase response nonlinearity of the utilized low-pass filter. A comparison with some of the existing fullband and low-pass differentiators shows that proposed differentiators require less multiplications, while their phase and magnitude responses are either better or slightly worse than those of existing differentiators.     

Time-interleaved SAR ADC design with background calibration

In this article, a low power time-interleaved SAR (TI-SAR) ADC is presented. Background calibration is used to improve the linearity of the ADC. Offset, gain, and capacitor mismatches between interleaved channels are calibrated by postprocessing the ADC output. Besides, a novel trimming-based calibration algorithm is used to calibrate the timing mismatches between channels. The proposed calibration algorithm is more power-efficient compared with most of its counterparts. The ADC consists of 18 parallel channels, a reference channel with two dummy channels, and a channel for timing calibration. The timing calibration channel is clocked only when the reference channel samples. The dummy channels are utilized to equalize the input load over time as they sample one after another to fill the gap where the reference channel does not sample. There is no need for any other dummy channels for timing calibration channel since it has low kickback noise over input driver. Each parallel channel operates at 111 ms/s while the reference channel runs at 105 ms/s. The aggregate sampling speed of the converter is 2 GS/s, and 52-dB SNDR is accomplished near Nyquist frequencies.     

光电跟踪系统前馈速度求解方法

针对脱靶量滞后引起系统误差导致光电跟踪系统不能准确测距的问题,提出了加入前馈速度提高跟踪系统无差度的复合控制策略;以等效正弦和目标模拟航路为仿真模型,通过基于最小二乘的多项拟合算法对目标航迹实时预测以及跟踪微分器或差分低通滤波器求解目标前馈速度,对前馈速度求解算法进行了软件仿真,仿真结果表明：航迹误差与前馈速度误差均满足实际系统要求;将此算法应用于某型光电跟踪系统,在外场试验中对特定目标的稳定最大跟踪误差在0．4 m以内。     

跟踪微分算法在半捷联稳定平台中的应用研究

以半捷联稳定平台技术研究为背景,分析了快速准确获得导引头角速度的重要性,介绍了跟踪微分算法的工作原理,通过数学仿真和导引头平台实验,将经典微分算法、跟踪微分算法的输出信号相比较,并将跟踪微分器输出信号与速率陀螺输出信号进行对比。结果表明,跟踪微分算法具有良好的微分和抗干扰能力,可行性较强。     

永磁直线同步电机ADRC控制系统

纹波推力扰动、负载扰动、摩擦力扰动和其他不确定性扰动严重影响永磁直线同步电机(PMLSM)控制系统的性能,对控制系统的抗干扰能力提出了更高的要求。本文采用自抗扰控制(ADRC)方法,利用扩张状态观测器估计所有未知扰动作用量并给予实时动态补偿,从而抑制未知扰动实现"自抗扰"控制,同时估计出速度及其微分;跟踪微分器给出了一种计算微分的有效方法,并根据PMLSM的承受能力安排速度指令过渡过程;采用更合适的非线性PD误差反馈率计算控制量。利用基于Matlab/Simulink的xPC Target构建控制系统实验平台,实验结果表明,采用ADRC的PMLSM控制系统具有很强的抗扰性和静动态特性。     

基于小波滤波和跟踪微分器的介质损耗因数检测方法

提出了一种新的介质损耗因数检测方法,将电压与电流信号经过小波滤波得到基波分量,利用跟踪微分器求得电压的一阶微分信号,再根据电压信号、电流信号和电压一阶微分信号计算介质损耗因数。仿真结果表明:该算法物理意义明确、计算简单、测量结果精确,可用于介质损耗因数的离线测量与在线监测。     

基于增量反步的复合翼无人机全包线姿态控制

针对某型复合翼无人机强非线性、不确定性和多模态的问题,从不确定性补偿非线性控制方法、跟踪微分器加速度测量和直接切换方法等角度开展全包线飞行控制研究。针对气动参数不确定问题,基于角加速度补偿方法,提出一种基于新型微分跟踪器的增量反步方法(incrementalbacksteppingcontrol,IBKS);为解决多模态特性问题,设计基于策略的直接切换方法,利用控制器参数切换实现复合翼无人机全包线姿态控制;通过不同模态下的仿真选取不同模式下的控制器参数,并联合选取的参数对起飞过程进行仿真。结果表明：所提姿态控制方法在样例复合翼无人机参数摄动30%的情况下,相较于反步法提高了66.8%的俯仰角控制精度,能消除攻角抖振,提升飞行品质。