跟踪微分器在里程仪数据处理中的应用研究

对从里程仪输出的路程增量信号中提取载体运动速度的问题进行了研究.为了获得更高精度的载体运动速度,利用跟踪微分器将载体运动速度从里程仪输出的路程增量信号中提取出来,并与传统的一阶差分算法进行比较,结果表明前者可以有效的抑制噪声放大问题,并具有较强的抗干扰能力,且算法简单,参数调节方便,滤波效果良好.最后通过计算机仿真验证了该算法的有效性,为构建捷联惯导/里程仪组合导航系统奠定了基础.     

基于自抗扰控制的火电厂主汽温控制系统及其参数整定

自抗扰控制器（ADRC）是通过改进经典比例积分微分（PID）控制的缺陷而形成的新型控制器,性能优良并且算法简单。针对火电厂过热汽温控制系统的大滞后、大惯性以及动态特性随工况变化的不确定性等特点,为了提高控制系统的动态性能和鲁棒性,文中给出了主汽温的自抗扰控制方案,该控制方案不需要精确模型参数而实现干扰补偿。在电厂热工过程控制实时仿真平台STAR-90上,使用集散控制系统自身控制模块实现了自抗扰控制系统的构建,这对于工程实际应用具有重要意义。以某超临界600 MW直流锅炉发电机组仿真机的主汽温为对象,进行ADRC控制下的变工况、10%扰动和快速减负荷（RB）实时仿真试验。结果表明,用ADRC技术建立的过热汽温控制系统与PID控制系统相比,该系统对被控对象特性的不确定性和外部扰动具有较强的适应性和鲁棒性,具有优良的控制性能。     

低谐波失真的CMOS正弦波振荡器设计

本文设计了一种具有低谐波失真输出的CMOS正弦波振荡器.该振荡器以RC有源微分电路作为选频回路.在实际电路设计中应计及运算放大器的频率特性,由此可得RC有源微分电路为二阶高Q电路.该电路具有良好的选频特性,大幅降低了振荡器输出的谐波失真,并配合移相和可变增益电路以满足振荡器起振条件.使用本文设计的CMOS运算放大器,该振荡器可起振的带宽可达200 Hz~2 MHz,其谐波失真小于通带噪声.以输出正弦波频率为100 kHz为例,给出了Hspice仿真结果.     

Command filter-based adaptive neural network controller design for uncertain nonsmooth nonlinear systems with output constraint

This paper investigates the command filter-based adaptive neural network tracking control problem for uncertain nonsmooth nonlinear systems. First, an integral barrier Lyapunov function is introduced to deal with the symmetric output constraint and make the output comply with prescribed restrictions. Second, by the Filippov's differential inclusion theory and approximation theorem, the considered nonsmooth nonlinear system is converted to an equivalent smooth nonlinear system. Third, the Levant's differentiator is used to deal with the “explosion of complexity” problem. An error compensation mechanism is established to attenuate the effect of the filtering error on control performance. Then, an adaptive neural network controller is set up by resorting to the backstepping technique. It is strictly mathematically proved that the tracking error can converge to an arbitrarily small neighborhood of the origin and all the signals in the closed-loop system are semi-globally uniformly ultimately bounded. Finally, a numerical example and an application example of the robotic manipulator system are provided to demonstrate the availability of the proposed control strategy.