Actuator fault diagnosis of singular delayed LPV systems with inexact measured parameters via PI unknown input observer

作者：Hassanabadi Amir Hossein; Shafiee Masoud; Puig Vicenc

来源：IET Control Theory and Applications, 2017, 11(12): 1894-1903.

DOI：10.1049/iet-cta.2016.1304

• fault diagnosis
• linear parameter varying systems
• actuators
• observers
• optimisation
• actuator fault diagnosis
• singular delayed LPV system
• inexact measured parameters
• PI unknown input observer
• SDLPV system
• polytopic proportional integral unknown input observer
• PI-UIO
• convex optimisation problem
• LMI constraints

In this study, actuator fault diagnosis of singular delayed linear parameter varying (SDLPV) systems is considered. The considered system has a time-varying state delay and its matrices are dependent on some parameters that are measurable online. It is assumed that the measured parameters are inexact due to the existence of noise in real situations. The system with inexact measured parameters is converted to an uncertain system. Actuator fault diagnosis is carried out based on fault size estimation. For this purpose, the system is transformed to a polytopic representation and then a polytopic proportional integral unknown input observer (PI-UIO) is designed. The proposed observer provides simultaneous state and actuator fault estimation while attenuating, in the sense, the effects of input disturbance, output noise and the uncertainty caused by inexact measured parameters. The design procedure of PI-UIO is formulated as a convex optimisation problem with a set of Linear Matrix Inequality (LMI) constraints in the vertices of the parameter domain, guaranteeing robust exponential convergence of the PI-UIO. The efficiency of the proposed method is illustrated with an electrical circuit example modelled as an SDLPV system.

• 出版日期2017-8-11