Application of fault detection and isolation to a pneumatic actuation system

This paper discusses research carried-out on the development and validation (on real plant) of a parity-equation based fault detection and isolation (FDI) system for a pneumatic actuator. A mechanistic model of the system is developed and validated in order to derive suitable parity equations for the pneumatic actuation system. The parity equations are then formulated and used to generate residuals that, in turn, are analysed to determine whether faults are present in the system. Details of the design process are given and the experimental results demonstrate that the approach can successfully detect and isolate faults associated with the sensors, actuators (servo-valves and piping) and the pneumatic cylinder itself. The work is part of a BAE SYSTEMS’ sponsored project to demonstrate advanced control and diagnosis concepts on a Stewart-Gough platform.