A Strategy for fault tolerant control in Networked Control Systems in the presence of Medium Access Constraints

This paper deals with the problem of fault-tolerant control of a Network Control System (NCS) for the case in which the sensors, actuators and controller are interconnected via various Medium Access Control protocols which define the access scheduling and collision arbitration policies in the network and employing the so-called periodic communication sequence. A new procedure for controlling a system over a network using the concept of an NCS-Information-Packet is described which comprises an augmented vector consisting of control moves and fault flags. The size of this packet is used to define a Completely Fault Tolerant NCS. The fault-tolerant behaviour and control performance of this scheme is illustrated through the use of a process model and controller. The plant is controlled over a network using Model-based Predictive Control and implemented via MATLAB© and LABVIEW© software.