工业过程随机稳态优化控制算法的鲁棒性分析

本文给出了一种随机稳态优化算法的灵敏度分析，讨论算法解对参数变化的关系。这些参数代表系统结构参数或噪声向量的某些数字特征．     

Comparative Study of Different Adaptive Window Protocols

We study an Adaptive Window Protocol (AWP) with general increase and decrease profiles in the presence of window dependent random losses. We derive a steady-state Kolmogorov equation, and then obtain its solution in analytic form for particular TCP versions proposed for high speed networks, such as Scalable TCP and HighSpeed TCP. We also relate window evolution under an AWP to workload process in queueing systems; this observation gives us a way to compare various AWP protocols.     

Stabilization of inter-area and/or oscillatory modes in large-scale power system by voltage impedance power system (VIPS) apparatus based on decentralized control scheme

New technologies such as power electronics have made it possible to change continuously the impedance of a power system not only to control power flow but also to enhance stability. A power system incorporating a variable impedance apparatus such as a variable series capacitor (VSrC) and high-speed phase shifter (HSPS) is called VIPS (Variable Impedance Power System) by the authors. This paper proposes a novel control method of VIPS apparatus such as VSrC and HSPS installed at an interconnecting point for stabilizing inter-area unstable and/or oscillatory modes. The proposed design method of the control system is a kind of hierarchical decentralized control method of a large-scale power system based on a Lyapunov function. Under the proposed control scheme, each subsystem can be stabilized independently by local controllers such as AVR, speed governor and PSS, and then the whole interconnected system can be stabilized by VIPS apparatus taking into account interactions between subsystems. The effectiveness and robustness of the VIPS apparatus control are shown by numerical examples with model systems including a large-scale power system.     

Steady-state torque control system with secondary-current feedback for three-phase squirrel-cage induction motors

This paper presents a highly stable steady-state torque control system with a feedback of a secondary current signal. The torque control system is constructed with a feedback of the secondary current (I₂) signal using a quick response magnetic-field sensor constructed with an amorphous core multivibrator bridge, which can solve the secondary resistance change problem for temperature variation in the IM. Moreover, we added a state feedback to the system to improve the response speed for the unit step function of a torque order. The I₂ sensor method has advantages especially at a low-speed range, in which conventional method using an integrator shows control errors.     

固定化酵母粒子中生产乙醇的定态分岔行为研究

运用变分原理和打靶法将分布参数系统的非线性边值问题转化为集总参数系统的初值问题，基于延拓算法，研究了固定床中球形固定化酵母粒子表面乙醇和葡萄糖浓度随参数的变化关系，得出了单颗粒固定化酵母生产乙醇的多定态特性。结果表明：随系统尺度三的变化，方程出现分岔点；方程的解与液相主体浓度有关。在某些条件下酵母粒子表面浓度有三个定态：在多定态区域，随三的增加，方程一个解支的乙醇浓度迅速增加，从而可以在固定床中通过控制粒径而使反应器达到较高的产率。研究结果为固定床反应器的开工及控制提供了重要的理论依据。     

复杂机动动作最优航迹控制模型及操纵特性分析

为了提高驾驶员对机动动作的控制能力,从驾驶员操纵角度避免机动动作过程中的风险,提出以控制量变化率作为优化参数的机动动作最优航迹控制模型.将机动动作划分为彼此相连的轨迹片段,轨迹片段划分合理,则每个轨迹片段具有相同的控制量变化率,控制量变化率不但能够给出机动动作控制量的输入,更重要的是能够反映机动动作过程中驾驶员操纵的快慢程度.使用小生境稳态遗传算法(niching steady-state genetic algorithm,niching SSGA)对最优航迹控制模型进行求解,求解结果为机动动作最优控制量变化率序列,以该序列对应的控制量作为机动动作的输入,能够实现一个标准的机动动作.仿真实验部分以典型纵向机动动作斤斗及横侧向机动动作桶滚为例进行分析,研究了两类动作的最优控制量变化率序列,并对两类动作的操纵特性进行了分析.     

具有数据包丢失的离散随机不确定系统的线性最优满阶估值器

研究了具有数据包丢失和随机不确定性离散随机线性系统的状态估计问题.其中数据包丢失是随机的,且满足Bernoulli分布,系统矩阵中的随机不确定性由一个白色乘性噪声来描述.首先,通过配方方法,提出了最小均方意义下的无偏最优线性递推满阶滤波器.所提出的滤波器用到了当前时刻和最近时刻接收到的观测来保证线性最优性.与多项式滤波和增广滤波器相比,本文的滤波器具有较小的计算负担.然后,基于所获得的线性滤波器推导了线性最优预报器和平滑器.进一步研究了线性最优估值器的渐近稳定性,给出了稳态特性存在的一个充分条件.最后,通过两个仿真例子验证了所提估计算法的优越性.     

化工过程稳态模拟技术的现状和发展趋势

本文介绍了化工过程稳态模拟技术及其数学方法、计算环境和软件开发的现状和发展趋势。     

用稳态法测量轮胎橡胶复合材料的导热系数

利用稳态法测试了4种轮胎橡胶复合材料的导热系数，在测试温度范围内，实验结果与温度线性相关。对误差进行了分析，并用校核实验验证了实验装置的准确性和精确性。     

带有止步的成批到达的M~x/M/1/N多重工作休假排队系统

研究了带有止步的M~x/M/1/N多重工作休假排队系统。顾客成批到达,到达后每批中的顾客,或者以概率决定进入队列等待服务,或者以概率1止步。系统中一旦没有顾客,服务员立即进入多重工作休假。利用马尔科夫过程理论和矩阵解法求出了稳态概率的矩阵解,并得到了系统的平均队长、平均等待队长以及顾客的平均止步率等性能指标。