Robust fault detection for networked systems with communication delay and data missing

Xiao He, Zidong Wang, D.H. Zhou
2009 Automatica  
In this paper, the robust fault detection problem is investigated for a class of discrete-time networked systems with unknown input and multiple state delays. A novel measurement model is utilized to represent both the random measurement delays and the stochastic data missing phenomenon, which are typically resulted from the limited capacity of the communication networks. Network status is assumed to vary in a Markovian fashion and its transition probability matrix is uncertain but reside in a
more » ... nown convex set of a polytopic type. The main purpose of this paper is to design a robust fault detection filter such that, for all unknown inputs, possible parameter uncertainties as well as incomplete measurements, the error between residual and fault is made as small as possible. By casting the addressed robust fault detection problem into an auxiliary robust H∞ filtering problem of a certain Markovian jumping system, a sufficient condition for the existence of the desired robust fault detection filter is established in terms of linear matrix inequalities. A numerical example is provided to illustrate the effectiveness and applicability of the proposed technique. Control systems where sensors, controllers, actuators and other system components communicate over a communication network are a type of distributed control systems referred to as networked control systems (NCSs) [1, 2] . The use of a communication network offers advantages in terms of reliability, enhanced resource utilization, reduced wiring and reconfigurability. As such, network-based analysis and designs have many industrial applications in, for example, automobiles, manufacturing plants, aircrafts, and HVAC systems. However, implementing a control network over a communication network induces stochastic delays and packet dropouts that inevitably degrade performance and could be a source of instability. The problem of designing NCSs against network-induced communication delays and packet dropouts has recently attracted considerable research attention, see [3, 4] for some representative works. Fault detection and isolation (FDI), on the other hand, has been an active field of research over the past decades because of the ever increasing demand for higher performance, higher safety and reliability standards [5, 6] . Generally speaking, a fault detection process consists of constructing a residual signal which can then be compared with a predefined threshold. When the residual exceeds the threshold, the fault is detected and an alarm is generated [7] . In view of the wide usage of the network ca-
doi:10.1016/j.automatica.2009.07.020 fatcat:h2dscc4avjauvbflqbn2c4zx3m