基于光轴稳定性优化的机载高分辨率近红外光学系统设计研究

针对一些光轴稳定性要求较高的高空使用战斗机挂载光电系统,分析了光学系统设计中提高光轴稳定性的几点要素,给出了消热差公式的条件,推导了景深公式,并给出了四种提高途径：采用较大温差范围的光学全被动补偿无热化设计、降低公差灵敏度、提高结构件的刚度和强度、使用景深调焦机构(满足较大作用距离的机载高低空使用要求)。介绍了一种小型机载近红外无热化变焦系统的设计思路。该系统采用光学补偿,有4个透镜组(最后一组为景深调焦机构),在-55~70℃温度范围内均具有较好的像质、较宽松的公差特性和较好的光轴稳定性。     

模糊自适应PID控制器的设计研究

根据模糊自适应和PID控制的原理,,将二者有效结合,设计出了一种模糊PID控制器。文章主要是概述这种模糊PID控制器的参数、设计原则以及其控制特点。最后,借助MATLAB的工具软件进行仿真测试,结果表明,这种模糊PID控制器较传统PID控制器更容易实现,能够有效提高控制能力,具有调节时间短,超调量小,抗干扰性和实时性强等优点,工程应用方便、快捷。     

基于自适应控制策略的医用呼吸机控制器设计

本文基于自适应控制策略对医用呼吸机的控制原理、控制规则以及控制器核心硬件的相关设计问题进行了详细分析,结果表明医用呼吸机控制器模糊自适应推理过程中常常遇到实时性差的问题,通过离线数据处理能够有效解决,运用最大隶属度法可以对模糊的输出量快速进行去模糊计算。     

一种基于序列调制的自适应抖动抑制方案

针对指针调整将会在SDH网络与PDH网络交界处引起大幅度的低频抖动的问题,文章在现有研究成果的基础上,提出了一种基于序列调制的自适应抖动抑制方案,该方案采用新的基于统计预测和缓存监测相结合的比特泄漏周期自适应调制方法,可以有效地避免相同极性的网络工作模式转换所造成的缓存器溢出损伤;给出了实现序列调制的设计原理,计算了网络在非劣化模式和劣化模式下的比特泄漏周期指标和序列调制时间指标.仿真与实际应用表明,该方案可以简单而有效地解决指针调整抖动的抑制问题.     

一种自适应带宽低抖动PLL设计

设计了一种宽调节范围自适应带宽的低抖动锁相环倍频器(PLL)。通过采用自偏置技术,使得电荷泵电流和运算放大器的输出阻抗随工作频率成比例变化,从而使阻尼因子保持固定、环路带宽跟随输入参考频率自动调整,以及PLL在整个输出频率范围内保持最佳的抖动性能。电路采用SMIC 0.18 μm CMOS工艺进行设计,后仿真验证表明,该PLL电路能够在0.35~2.1 GHz的输出频率范围内输出良好的低抖动信号,输出频率为2.1 GHz时,均方根抖动为2.47 ps。     

混合自适应滤波的光束抖动控制技术研究

在光束传输系统中,通常存在由于传输介质引起的能量与频率成反比的宽带扰动和平台振动引起的在某个特定频率点的窄带扰动,使得光束发生抖动或漂移,造成光斑能量下降.为了解决光束传输系统中由大幅度、高频率窄带扰动和宽带扰动引起光束抖动,设计了基于高速倾斜反射镜谐振补偿的混合自适应滤波器的光束抖动控制方法.该方法采用最小均方(LM...     

抖动偏频激光陀螺抖动信号的自适应对消

根据抖动偏频激光陀螺的输入、输出信号模型,提出利用自适应噪声对消技术消除陀螺抖动信号.使用恰当的算法,自适应噪声对消器能够自适应地跟踪并最佳地消除抖动信号,提取所需的惯性角速率信息.     

无抖动式多路时分复用控制器

叙述一种多路时分复用控制器的功能与原理，介绍其关键技术问题及解决方法，该项目已形成产品，它是有线电视台，闭路电视系统中多个频道时分复用某视频处理设备（如编辑机、字幕机、多画面处理机等）的一种通用仪器。     

自适应有源噪声控制器的设计与实现

论述了自适应有源噪声控制器的设计原理及实现方法，给出了通用型自适应有源噪声控制器的硬件结构和软件流程，作为实例，设计了一台通用型自适应有源噪声控制器，并提供了该控制器用于有源噪声控制的实验结果。     

像锐化自适应光学系统中的多极值问题

本文对多极值现象产生的原因及其影响进行了详细分析,结果表明变形反射镜是产生多极值现象的原因,多极值现象限制了系统校正波前误差的范围。     

An adaptive fuzzy sliding-mode controller for servomechanismdisturbance rejection

A two-level spring-lumped mass servomechanism system was constructed for disturbance rejection control investigation. This dynamic absorber is similar to a model of the serial-type vehicle suspension system. The lower level is actuated by two DC servo motors, to provide the specified internal and external disturbances to the vibration control system. The upper level has another DC servo motor to control the main body balancing position. In order to tackle the system's nonlinear and time-varying characteristics, an adaptive fuzzy sliding-mode controller is proposed to suppress the main mass position variation due to external disturbance. This intelligent control strategy combines an adaptive rule with fuzzy and sliding-mode control technologies. It has online learning ability for responding to the system's time-varying and nonlinear uncertainty behaviors, and for adjusting the control rules and parameters. Only seven rules are required for this control system, and its control rules can be established and modified continuously by online learning. The experimental results show that this intelligent control approach effectively suppresses the vibration amplitude of the body, with respect to the external disturbance     

An adaptive sliding-mode controller for discrete nonlinear systems

This paper presents a sliding-mode controller for a class of nonlinear discrete-time systems. The proposed controller uses a modified switching function that produces a low-chattering control signal. In order to improve the controller performance, an adaptive term is added to the original sliding-mode algorithm. This new feature uses an artificial neural network for online identification of the modeling error. Simulations and experimental results illustrate the main characteristics and performance of this approach,     

应用光学中几种光路调整的方法

本文利用散斑、太保、莫尔条纹等效应,提出了几种调整相干光信息处理系统中焦点的位置、光束准直及光学元件位置的方法.     

自适应压电振动盘控制器设计

振动给料机是工业控制自动化中常用的设备,压电振动盘是目前效率和稳定性最高的振动给料机,但在使用过程中存在共振点变化导致效率下降的问题。针对该问题,设计了适用于压电振动盘的自适应控制器。该控制器能够对压电振动盘的振动频率和幅值进行连续调节,模糊PID控制使得振动盘输出幅值保持稳定,自适应算法使振动盘始终工作在最佳振动频率。控制器采用准谐振开关电源,可以消除电网电压波动对系统工作的影响。设计结果表明:该控制器工作性能稳定,驱动效率高且产生的噪音较小。     

Power penalty due to jitter on optical communication systems

Two techniques to assess the performance degradation of optical communications systems due to jitter are compared: a Gaussian approximation and a precise calculation. It is shown that, depending on the jitter distribution, the approximation may either under- or overestimate the performance degradation caused by jitter by a significant amount.     

机载激光通信的重复自抗扰视轴稳定控制

机载激光通信的视轴稳定是建立激光通信链路的前提。针对通信终端载体的非线性扰动和扰动模型未知造成视轴稳态误差较大的问题,结合自抗扰控制与重复控制,提出了重复控制补偿自抗扰算法,以完全消除周期性稳态跟踪误差。仿真实验结果表明,与自适应PID控制方法相比,重复控制补偿自抗扰算法可以有效抑制平台的非线性扰动,提高了系统的稳态精度,并且具有较快的响应速度与较强的鲁棒性。     

Power penalty due to decision-time jitter in optical communication systems

The effect of decision-time jitter on the performance of optical communication systems is evaluated theoretically. The jitter-induced noise and the associated power penalty are calculated for the uniform and Gaussian distributions of the time jitter. The results suggest that the time jitter should be ?(4B)?1 to keep the power penalty below 1 dB for a light-wave system operating at a bit rate B.     

Design and implementation of an adaptive controller for current-fedinduction motor

A model reference adaptive speed controller for a current-fed induction motor drive is proposed. The controller uses a proportional-integral (PI) adaptation to satisfy the hyperstability condition for load and machine parameter changes of the drive. Only the available information on the states and output of the reference model as well as the plant output are required. No explicit parameter identification is needed. The controller can be designed simply by using a reduced reference model without particularly degrading the performance, so it is easy to implement practically. The hardware implementation is detailed, and some experimental results are given to demonstrate its effectiveness     

谐振式光学陀螺的改进型伺服控制器设计

谐振式光学陀螺需要使用激光器频率锁定技术实现其中一路的频率锁定,探测另一路的谐振频率。在实现激光频率锁定后,陀螺系统会受环境因素的影响在锁频环路中产生超低频漂移,传统的比例积分伺服控制器产生的增益不能够抑制该漂移。本文采用一路为传统的比例积分控制器,另一路为低通滤波器与积分控制器,两路共同作用形成新型伺服控制器进行激光器的频率锁定,提高锁频环路的低频增益,抑制锁频路产生的超低频漂移,通过仿真理论证明其可行性,并进行系统测试,测得锁频环路中的Allan方差值为0.005°/s,且锁频路基本无漂移。     

GA and Lyapunov theory-based hybrid adaptive fuzzy controller for non-linear systems

In this present article, a new hybrid methodology for designing stable adaptive fuzzy logic controllers (AFLCs) for a class of non-linear system is proposed. The proposed design strategy exploits the features of genetic algorithm (GA)-based stochastic evolutionary global search technique and Lyapunov theory-based local adaptation scheme. The objective is to develop a methodology for designing AFLCs with optimised free parameters and guaranteed closed-loop stability. Simultaneously, the proposed method introduces automation in the design process. The stand-alone Lyapunov theory-based design, GA-based design and proposed hybrid GA–Lyapunov design methodologies are implemented for two benchmark non-linear plants in simulation case studies with different reference signals and one experimental case study. The results demonstrate that the hybrid design methodology outperforms the other control strategies on the whole.