Diagnosis on a Principle Environmental Control System
Diagnosis on a Principle Environmental Control System
Johan Nilsson
LiTH-ISY-EX-3067
Linköping Institute of Technology
Abstract
This thesis is carried out at the business unit Gripen of Saab
Aerospace within the section for Thermal Analysis and System
Simulation of General Systems. The work deals with automatic fault
detection with focus on the Environmental Control System (ECS). The
ECS main tasks are pressurization of cabin and cooling of avionics.
Automatic fault detection is traditionally performed mainly by using
limit checking of meas-ured signals and setpoint errors. An approach
with a number of drawbacks such as difficulty in handling system
transients and no systematic way for isolation of faults. Increasing
demands on safety, reliability and economy has caught a growing
attention for new diagnosis approaches. Model based diagnosis is found
to be an approach with potential to increase per-formance and adding
desired functionality. A principle model of the ECS is developed for
design and test of a model based diagnosis sys-tem. Not only the ECS
is modeled but also relevant faults, some faults well known from long
experience of the system and some hypothetical faults for the
exemplification of diagnosis methods. The benefits of a model based
diagnosis approach is compared to diagnosis methods implemented in the
ECS today.
Johan Nilsson
2000
Informationsansvarig: webmaster
Senast uppdaterad: 2021-11-10
LiU Homepage
