基于蚁群-遗传算法的贴片机喂料器分配优化研究

针对在元器件贴装顺序已知的前提下研究拱架式贴片机的喂料器在喂料槽上分配优化的问题,给出了以贴片头在喂料槽移动距离最小化为优化目标的喂料器分配优化模型．利用蚁群算法与遗传算法的混合算法实现对贴片机的喂料槽分配问题进行求解,将蚂蚁搜索的结果进行迭代交换、交叉和变异．为了验证算法有效性,以20块实际生产的PCB为实例进行了测...     

测试转台摇摆运动的振幅自适应控制

在用测试转台(testturn-table)对陀螺、加速度计等惯导元件进行测试时,要求转台能做振幅精度要求很高的摇摆运动。然而由于转台本身的闭环幅频特性,转台实际的振幅很难等于给定的要求振幅。为了使转台的输出振幅等于给定振幅,该文设计用自适应的算法来补偿输入振幅,使输出振幅稳定在要求振幅上。利用带遗忘因子的最小二乘递推算法(Ls)对实际的输出振幅进行估计,并根据实际输出的振幅对输入振幅进行自适应补偿控制。文中给出了自适应算法的具体实现,进行了Matlab仿真。仿真表明,自适应控制算法有效地提高了转台的摇摆振幅精度。     

双层振动筛自动筛分最优振幅控制研究

为提高筛分效率,解决系统容易出现故障的问题,保证控制系统的稳定,提出双层振动筛自动筛分最优振幅控制方法.建立颗粒运动速度与筛分机运动学参数间关系函数,为分析振幅对自动筛分效率的影响提供依据.将筛分效率最高作为目标函数,并综合筛分设备性能与效率两方面因素,完成对目标函数的优化处理.在传统PID控制器基础上,筛分振幅偏差与...     

基于MODEM的远程控制系统在色选机中的应用

介绍了利用单片机ATMEGA162和嵌入式MODEM模块MT5634设计的一套色选机远程控制系统。详细介绍了MODEM的控制方法和控制协议以及工控机和MODEM的通讯协议和软件控制流程。该系统通过自行设计的基于工控机的人机接口软件,实现了对远地色选机灵敏度、脉冲宽度、延时和波形的监控和调整。     

模态密集空间结构的振幅优化鲁棒自适应控制

可控性关划密集模态空间结构控制的一个难点,针对这一问题,本文提出一种振幅优化控制方案,在适当配置系统极点的同时,优化可控性差模态的振幅;为适应不确知的初始状态,提出一种模型参考自适应方法,在线实现振幅优化控制,目的提驱动密集模态结构去跟踪一个慢变部分振幅较小的动态。理论上证明了,即使存在一定范围时变的模型不确定性,该方法仍能被结构的渐近稳定,仿真结果也表明,该方法为解决密集模态结构的控制问题提出了一条可行的途径。     

模糊与积分混合控制研究

在阐述了模糊与积分控制所应解决的两个关键问题的基础上，提出了两种模糊积分控制的具体方案，最后对两种方案的特点和应用进行了总结。     

基于CPLD的色选机信号采集处理系统

针对大米色选机中色差信号的特殊需求,设计了以CPLD为核心处理器件的色差信号处理系统,此系统可实现32路色选米道色差信号的同步采集,并输出控制指示灯和气枪.此系统应用于天津光学精密机械研究所的色选机产品,大大提高了色选机产品的性能和用户满意度.     

多自由度Van der Pol型系统振幅增大控制

研究多自由度Van der Pol型非线性振动系统振幅增大的控制,设计反馈控制器,用数值方法对控制系统的幅值进行了计算,绘制了在不同控制参数下,系统响应的时间历程曲线和极限环.研究表明通过调整控制参数,能够增大极限环的幅值,有工程应用价值,对高维系统的分岔控制研究有一定的理论意义.     

基于神经网络的回转窑建模及其优化控制设计

实现水泥回转窑温度稳定性控制,水泥回转窑熟料煅烧是一个涉及传质、传热和物理化学反应的复杂多变量、多扰动非线性过程。为了稳定回转窑烧成温度以提高孰料烧成质量,降低能耗,传统的控制方法,存在干扰大,稳定时间长等问题。在分析水泥回转窑工艺的基础上,采用Elman神经网络建立回转窑系统的模型,提出BP神经网络的PID控制方法,根据系统的运行状态,调节PID控制器的参数,以达到性能指标,设计了回转窑温度优化控制器,具有超调量小、动态性好、收敛速度快和控制精度高等优点。进行仿真的结果表明,回转窑烧成带温度逐渐趋于稳定,实现了对水泥回转窑的优化控制。     

单螺杆大振幅振动对挤出影响的数值模拟研究

借助CFD专用模拟软件PolyFlow,本文模拟了动态塑化单螺杆挤出机计量段中,聚合物熔体在单螺杆大振幅振动条件下的三维非等温输送流场,研究了大振幅振动力场对挤出产量、功率及螺杆特性的影响。模拟结果显示:振动参数有一个可选范围,当螺杆振动幅值超过该范围而落入横流反向区时,挤出流率将急剧下降,产能比严重降低,螺杆特性变软。     

Global output feedback control for nonlinear cascade systems with unknown output functions and unknown control directions

This paper investigates the output feedback control for the uncertain nonlinear system with the integral input‐to‐state stable (iISS) cascade subsystem, which allow not only the unknown control direction but also the unknown output function. The unknown output function only needs to have a generalized derivative (which may not be derivable), and the upper and lower bounds of the generalized derivative need not to be known. To deal with the challenge raised by the unknown output function and the unknown control direction, we choose a special Nussbaum function with a faster growth rate to ensure the integrability for the derivative of the selected Lyapunov function. Then, a dynamic output feedback controller is designed to drive the system states to the origin while keeping the boundedness for all other closed‐loop signals. Moreover, via some appropriate transformations, the proposed control scheme is extended to deal with more general uncertain nonlinear cascade systems with quantized input signals. Finally, two simulation examples are given to show the effectiveness of the control scheme.     

电压型PWM整流器新型相幅控制

在分析其控制原理的基础上,提出了用整流器输入前端电压滞后角作为输入变量控制网侧输入电流的相位幅值控制的新方法,解决了传统相幅控制方法存在的问题。建立了基于三相静止坐标系和两相旋转坐标系的整流器数学模型,并验证了这个新的控制方法的有效性。     

Robust output tracking of constrained perturbed linear systems via model predictive sliding mode control

A robustifying strategy for constrained linear multivariable systems is proposed. A combination of tracking model predictive control with output integral sliding mode techniques is used to completely reject bounded matched perturbations. It can be guaranteed that all constraints on inputs, states, and outputs are satisfied although only output information is used. Finally, real‐world experiments with an unstable plant are presented in order to demonstrate the validity and the effectiveness of the proposed approach.     

Dynamic output feedback integral sliding mode control design for uncertain systems

This paper addresses the problem of designing a dynamic output feedback sliding mode control algorithm for linear MIMO systems with mismatched parameter uncertainties along with disturbances and matched nonlinear perturbations. Once the system is in the sliding mode, the proposed output‐dependent integral sliding surface can robustly stabilize the closed‐loop system and obtain the desired system performance. Two types of mismatched disturbances are considered and their effects on the sliding mode are explored. By introducing an additional dynamics into the controller design, the developed control law can guarantee that the system globally reaches and is maintained on the sliding surface in finite time. Finally, the feasibility of the proposed method is illustrated by numerical examples. Copyright © 2011 John Wiley & Sons, Ltd.     

Optimal periodic output feedback control: a continuous-time approach and a case study

This article deals with the problem of optimal static output feedback control of linear periodic systems in continuous time, for which a continuous-time approach, which allows to deal with both stable and unstable open loop systems, is presented. The proposed approach is tested on the problem of designing attitude control laws for a Low-Earth Orbit (LEO) satellite on the basis of feedback from a triaxial magnetometer and a set of high-precision gyros. Simulation results are used to demonstrate the feasibility of the proposed strategy and to evaluate its performance.     

基于快速输出采样反馈的网络控制系统滑模控制

针对网络控制系统的网络诱导时延问题,提出了一种新的滑模控制方法。通过快速采样被控对象输出,建立了具有线性时不变被控对象的网络控制系统的离散模型。在此基础上,用极点配置法给出了滑模切换面参数,设计了输出反馈离散滑模控制器。仿真结果验证了该控制方法的有效性。     

基于支持向量机的彩色图像水印算法

提出了一种基于回归型支持向量机(SVR)的盲检测彩色图像水印算法。为了改善可见性,根据人眼视觉特性（HVS）自适应选择其嵌入位置。水印嵌入是通过修改图像中像素蓝色通道信息来实现,水印提取时结合图像局部相关性,选取稳定的特征向量并获取SVR训练模型,进而利用SVR训练模型进行预测提取数字水印信息。在嵌入过程中通过高斯模板来均衡调整嵌入水印后对宿主图像影响的强度,仿真实验证明本文算法不仅具有非常好的透明性,而且对诸如叠加噪声、JPEG压缩、平滑滤波、几何变换、图像增强等攻击也具有很好的鲁棒性。     

基于幅度调制和视觉掩蔽特性的彩色图像水印

提出了一种基于幅度调制的盲检测彩色图像水印算法,为了改善可见性,根据人眼视觉特性（HVS）自适应选择其嵌入位置。水印嵌入是通过修改图像中像素蓝色通道信息来实现的,而水印提取是基于对嵌入水印位置的邻域像素值的线性组合的预测而完成的。在嵌入过程中通过高斯模板来均衡调整嵌入水印后对宿主图像影响的强度。仿真实验证明该文算法不仅具有非常好的透明性,而且对诸如叠加噪声、JPEG压缩、平滑滤波、几何变换、图像增强等攻击具有很好的鲁棒性。     

Static output feedback fault tolerant control using control allocation scheme

This paper describes two novel schemes for fault tolerant control using robust suboptimal static output feedback design methods. These schemes can also be employed as actuator redundancy management for overactuated uncertain linear systems. In contrast to many existing methods in the literature that assume the control input matrix (i) is not of full‐rank such that it can be factorized into two matrices and (ii) it does not involve uncertainty, these schemes can be applied to systems whose control input matrix cannot be factorized and/or involve uncertainty. The so‐called virtual control, in these schemes, is calculated using suboptimal ‐based static output feedback design schemes constructed to be robust against uncertainties emanating from inherent input matrix uncertainty and visibility of the control allocator to the controller. Then, using two proposed control allocation schemes (fixed and on‐line), the obtained virtual control signal is redistributed among remaining (redundant or nonfaulty) set of actuators. As the proposed schemes are modular‐based, they can be employed as real‐time fault tolerant control schemes with no need to reconfigure the controller in the case of actuator faults or failures. The effectiveness of the proposed schemes is discussed and compared with numerical examples.     

模糊控制在细分脉冲实时输出中的应用

本文给出了磁性编码器细分脉冲输出的方案设计思想,同时提出了一种基于模糊控制策略的细分脉冲输出控制方案,该控制方案不需要建立复杂的数学模型,可在低成本的单片机系统上实现。仿真实验证明了基于模糊控制策略的控制方案的有效性和可行性。