有时延和数据包丢失的网络控制系统故障检测

Fault Detection of Networked Control Systems with Time-delay and Data Packet Dropout

针对同时存在网络时延和数据包丢失情况下的网络控制系统(NCS),研究了基于观测器的故障检测问题。对网络诱导时延大于一个采样周期的NCS,构建了增广系统模型。对于已知的数据包丢失率,在数据包正常传输和丢包发生的情况下分别设计了故障观测器,将观测器误差系统视为具有两事件率约束的异步动态系统(ADS),利用ADS理论给出了系统稳定的充分条件,基于矩阵不等式优化理论给出了故障观测器的设计方法。通过计算实际系统和故障观测器输出之间的残差,实现了NCS的故障检测。仿真算例验证了所提出方法的有效性。

With the presence of time-delay and packet dropout effects, the problem of observer-based fault detection for a class of networked control systems （NCS） is addressed. An augmented model is constructed for a kind of NCS with network-introduced delay larger than one sampling period. Based on the fixed rate of packet dropout, the fault observers of the NCS are designed in both cases of packet dropout and successful transmission respectively. The observer-based estimation error system for fault detection can be viewed as an asynchronous dynamical system （ADS） with rate constraints on two events. Based on the ADS theory, the sufficient condition of exponential stability for the system is presented, and the fault observer design method based on matrix inequalities theory is also provided. By computing the residual between the output of the practical system and the fault observer, the fault of NCS can be detected. The numerical example validates the method.