基于多变量统计方法的产品质量控制

提出了一种多变量统计质量控制方法来减小由于过程扰动引起的产品质量变化.该方法首先通过正常工况的历史数据,建立一个部分最小二乘的回归模型,利用高采样频率的过程测量值来预测质量变量的值.预测误差作为部分最小二乘逆模型的输入得到过程操纵变量的调节量,通过调节过程操纵变量来抑制过程扰动,减小质量变量的变化.所提出的多变量统计质量控制方法在TE过程中得到了验证.仿真结果表明,与传统的PID质量控制方法相比,所提出的方法能减小由过程扰动引起的质量变化.     

基于输入整形的线性二次型调节器及其应用

针对桥式起重机这一类不完全控制系统,提出了一种新的混合控制方案,有机地结合了鲁棒输入整形技术以及线形二次型调节器(LQR).该方案中,结合起重机模型的特点,采用LQR控制器来同时实现小车的定位以及消除负载的残留振荡.输入整形技术采用频域的零点配置方法设计多峰鲁棒输入整形器用来进一步减小负载的瞬时振荡,保障安全作业;所设计的混合方案在结构上简单实用,适合实际应用.仿真结果证明了该方案的良好性能.和基本的LQR控制进行比较,该方案可同时实现小车的定位以及消除负载的残留振荡,并可有效地减小负载的瞬时振荡,体现了良好的综合性能.     

采用逆系统设计和二次型最优控制提高变风量箱的性能

采用逆系统设计方法对变风量空调箱的控制系统,包括控制系统的内环(风量控制回路)和外环(房间温度控制回路),进行逆系统设计.消除了在设计时将非线性系统做近似线性化处理所带来的设计缺陷;同时采用二次型最优控制技术对变风量空调箱的控制器进行优化设计,使控制器的参数达到最优值.逆系统设计方法与二次型最优控制技术相结合能有效地改进和提高变风量箱的控制品质和性能.     

迭代、直接搜索联合优化方法及其在化工中的应用

本文提出了一种迭代、直接搜索联合优化方法,该方法集迭代Marquardt法快速收敛和直接搜索单纯形方法适应性强的特点,通过化工数学模型的具体应用表明,该方法可广泛地用于最小二乘问题。     

甲醛生产过程的数学模型与优化

本文在甲醇反应机理探讨和现场试验基础上,建立了反应过程数学模型。通过优化计算,求得了在满足产品质量和产量约束条件下使原料单耗最低的最优操作条件,并在实际生产装置上得到了实施。计算机离线指导生产表明,本文所提供的优化条件,可显著地降低原料单耗,提高产品质量,并能延长他化剂使用寿命,每年的经济效益在47万元以上。     

非线性大系统多目标优化的交互式满意分解方法

本文提出了交互式二级算法,在此基础上又提出了交互式三级算法,统称为交互式满意方法。利用加权切贝雪夫方法,将多目标优化问题化简为单目标优化问题。采用大系统分解协调理论完成了对决策空间的分解,降低了系统的维数。通过引入代值目标完成了对目标空阿的分解,兼顾了系统的整体利益和局部利益。运用希望水平方法实现了人机交互过程。该方法具有一定的智能水平,所需的计算机内存容量较小,收敛速度较快。用数值例子表明了其实用性和有效性。     

Robust stability analysis of uncertain discrete-time systems with state delay

The sufficient conditions of stability for uncertain discrete-time systems with state delay have been proposed by some researchers in the past few years, yet these results may be conservative in application. The stability analysis of these systems is discussed, and the necessary and sufficient condition of stability is derived by method other than constructing Lyapunov function and solving Riccati inequality. The root locations of system characteristic polynomial, which is obtained by augmentation approach and Laplace expansion, determine the stability of uncertain discrete-time systems with state delay, the system is stable if and only if all roots lie within the unit circle. In order to analyze robust stability of system characteristic polynomial effectively, Kharitonov theorem and edge theorem are applied. Example shows the practicability of these methods.     

Optimal closed-loop identification test design for internal model control

In this paper, optimal cloeed-loop test design for control is studied. The identified model is used for controller design. The control scheme used is internal model control (IMC) and the design constraint is the power of the process output or that of the reference signal. The measure of performance is the variance of the error between the output of the ideal closed-loop system (with the ideal controller) and that of the actual closed-loop system (with the controller computed from the identified model). Optimal spectrum formulae can be used to determine the PRBS signal in industrious identification.     

Nonlinear Statistical Process Monitoring and Fault Detection Using Kernel ICA

A novel nonlinear process monitoring and fault detection method based on kernel independent component analysis (ICA) is proposed. The kernel ICA method is a two-phase algorithm: whitened kernel principal component (KPCA) plus ICA. KPCA spheres data and makes the data structure become as linearly separable as possible by virtue of an implicit nonlinear mapping determined by kernel. ICA seeks the projection directions in the KPCA whitened space, making the distribution of the projected data as non-gaussian as possible. The application to the fluid catalytic cracking unit (FCCU) simulated process indicates that the proposed process monitoring method based on kernel ICA can effectively capture the nonlinear relationship in process variables. Its performance significantly outperforms monitoring method based on ICA or KPCA.     

基于模型组件技术的通用离散事件动态系统仿真模型

针对传统离散事件动态仿真软件可重用性差的缺陷，提出了基于组件技术的设计方法，给出了基于组件技术的离散事件动态系统通用的模型接口及原型实现，开发了类似Matlab的离散事件动态系统仿真环境，该仿真工具通过拖放创建模型，联线建立模型间逻辑联系，并在炼钢连铸车间物流仿真中得到了运用。该设计方法还可以推广到其他柔性制造系统的仿真应用中。