基于动态观测器零极点优化的网络控制系统故障检测

Pole-zero optimization design of dynamic observer for fault detection of networked control systems

针对网络化控制系统中在有限频扰动和噪声下的传感器故障检测问题,构建一种新型的观测器结构:动态观测器.利用动态观测器零点可配置这一新特性,提出零点和极点联合优化配置的故障检测方法.所提出的动态观测器是在传统比例积分观测器的基础上扩展而成,更具一般性,具有零点可配置的特点,能够克服传统观测器零点是固定的限制.将动态观测器的零点配置到有限频率测量扰动信号和网络传输延时等外部扰动的特征频谱处,利用零点的特性更好地衰减扰动对残差的影响.给出观测器故障检测的综合性能指标,结合H2/H∞优化方法优化动态观测器极点.最后以网络化两轮自平衡机器人的模型为例,比较动态观测器、比例积分观测器、比例观测器的故障检测效果.仿真结果验证了所提动态观测器故障检测方法的优势和有效性.

This paper constructs a new type of observer structure called dynamic observer for the problem of sensor fault detection under finite frequency disturbance and noise in networked control systems. A joint optimization of zero and pole for fault detection is proposed, which features a dynamic observer whose zero can be freely assigned. The dynamic observer is based on the traditional proportional integral observer and can be expanded to more general types.It has the property that its zero can be assigned to anywhere. The dynamic observer overcomes the problem of invariant zero associated with traditional observers. Zero of the dynamic observer is assigned to the characteristic spectrum of the finite frequency disturbance signal and the network transmission delay, so the effect of disturbance on the residual can be better attenuated. A comprehensive performance of the observer for fault detection is proposed. The pole of the dynamic observer is designed by the H2/H∞ method to optimize the comprehensive performance of the observer. Finally, taking the model of a networked two-wheel self-balancing robot as an example, the fault detection performance of the dynamic observer, the proportional integral observer and the proportional observer are compared. The comparison results show the advantages and effectiveness of the dynamic observer fault detection method.