基于等分采样周期的网络控制系统故障检测

Fault detection for network control system based on equally divided sampling period

考虑一类时延网络控制系统,假定其存在输出时延,对其进行故障检测。通过提高控制器端的采样频率,将传感器采样周期等分,这样可以将网络时延近似看成控制器端采样周期的整数倍。在此基础上,建立了基于离散异步动态系统的故障观测器误差方程,并将观测器稳定条件归结为一个线性矩阵不等式。当系统正常时,只要给定的不等式条件成立,该观测器系统就是稳定的。当系统发生故障时,观测器残差能够迅速发生跳变,从而检测出故障的发生。最后通过仿真实例验证了方法的有效性。

Considering a class of network control system with time delays, the fault detection was carried out when the output delays were present. By increasing sampling frequency in controller and equally dividing the sampling period of the sensor, the time delays could be approximated to several times of the sampling period of the controller. On this basis, the error equation of the fault observer was constructed based on a discrete asynchronous dynamical system. And a linear matrix inequality decided the stabiIity condition of this observer. When the system is normal and the given inequality condition is satisfied, the observer system is stable. When a fault is present, the observer residue can change rapidly and the occurrence of the fault can be detected. Finally, an illustrative example was given to demonstrate the effectiveness of the proposed method.