研究一类带有网络传输时滞和去包的双率采样系统的网络化H_∞控制问题,假设对象状态变量被分成两个分向量,同一分向量的状态变量由同一类传感器以相同周期采样,且两类传感器的采样频率不同.采样后的分向量分别通过非理想网络传输到控制器端.考虑到双率采样、网络传输时滞和丢包现象,引入同步观测器来估计对象状态并设计基于估计状态的控制器来镇定双率采样系统.基于这个思路,将双率采样的网络化控制系统建模为带有两个时变时滞的连续系统.利用Lyapunov-Krasovskii泛函方法,以矩阵不等式形式给出该系统的稳定性判据和控制器设计方法.最后,通过数值例子验证所提方法的有效性.
The networked H∞ control for a class of dualrate sampling systems with network transmission delays and packet losses is investigated. State variables of the plant are assumed to be split into two sub-vectors. All state variables of the two sub-vectors are periodically sampled by two types of sensors, respectively, which each type of sensors has a different sampling rate. The two sampled sub-vectors are separately transmitted to the controller node over an imperfect network. Considering the dualrate sampling, network transmission delays and packet losses, a synchronized observer is introduced to estimate the state variables of the plant, and a controller based on the estimation is designed to stabilize the dualrate sampling system. Based on the above idea, a networked control system with dualrate sampling is modeled as a continuous-time system with two time-varying delays. By Lyapunov-Krasovskii functional method, some results of stability criterion and controller design for the system are obtained in terms of matrix inequalities (MIs). At last, some numerical examples are given to illustrate the effectiveness of the proposed method.