基于Lipschitz非线性系统的早期微弱FDAI

Incipient Weak Fault Detection and Isolation Based on Lipschitz Nonlinear Systems

为解决一种速度慢变、频率低、振幅较小的早期微弱故障问题,提出了基于Lipschitz非线性系统的早期微弱故障检测和隔离方法。首先,利用非奇异变换将原系统降阶成两个子系统,其中子系统1包含系统扰动和执行器故障,子系统2只包含执行器故障。然后针对子系统1引入H∞性能指标并设计滑模观测器抑制系统未知扰动及噪声,针对子系统2设计Luenberger观测器,同时设计故障隔离策略以解决多个执行器故障问题。接着,设计自适应阈值并将其与观测器产生的残差信息进行比较,完成系统早期微弱故障诊断。最后仿真算例说明,上述方案提升了故障检测的灵敏性和故障隔离的精确度。

To solve the incipient weak fault problem with slow speed variation,low frequency and small amplitude,this paper proposes incipient weak fault detection and isolation method based on the Lipschitz non-linear system.Initially,the original system was downscaled into two subsystems using non-singular transformations,where subsystem 1 contains system disturbances and actuator faults,and subsystem 2 contains only actuator faults.Then,a performance index H∞was introduced for subsystem 1 and a sliding mode observer was designed to suppress unknown disturbances and noise in the system,and a Luenberger observer was designed for subsystem 2.Some Fault isolation strategies were designed to address multiple actuator faults.Next,adaptive thresholds were designed and compared with the residual information generated by the observer to complete the system incipient weak fault diagnosis.Finally,the simulation example shows that the scheme improves the sensitivity of fault detection and the accuracy of fault isolation.