多模态动态核主成分分析的气液两相流状态监测

气液两相流流动过程作为一种非平稳过程, 其状态的变化具有时变性、非线性、随机性等复杂流动过程的特点, 其流动状态的实时监测对掌握其流动过程的产生、发展及转化, 保障实际生产的安全稳定运行具有重要意义. 特别是流动状态的过渡过程反映了流动状态的发展及演化, 其流动结构非常复杂. 针对气液两相流的3种典型流动状态及过渡转化过程, 在多传感器获取流动状态测试数据的基础上, 提出一种多模态动态核主成分分析方法. 通过采用动态自相关、互相关方法提取流动过程测试数据中的动态特性, 采用核方法提取非线性特性, 结合主成分分析建立不同典型流动状态的监测模型; 利用模型对不同典型流动状态进行判别, 并进一步实现流动过渡状态的监测. 通过对气液两相流实验装置中不同流动状态实验测试数据进行处理, 验证了所提出方法对典型流动状态判别的准确性及对过渡状态监测的有效性.     

Stability Analysis and Design of Uncertain Discrete‐time Switched Systems with Actuator Saturation Using Antiwindup and Multiple Lyapunov Functions Approach

The stability analysis and anti‐windup design problem is investigated for a class of discrete‐time switched systems with saturating actuators by using the multiple Lyapunov functions approach. Firstly, we suppose that a set of linear dynamic output controllers have been designed to stabilize the switched system without input saturation. Then, we design anti‐windup compensation gains and a switching law in order to enlarge the domain of attraction of the closed‐loop system. Finally, the anti‐windup compensation gains and the estimation of domain of attraction are presented by solving a convex optimization problem with linear matrix inequality (LMI) constraints. A numerical example is given to demonstrate the effectiveness of the proposed design method.