Diagnosis of Continuous
Valued Systems in Transient Operating Regions
Pieter J. Mosterman and Gautam Biswas
Center for Intelligent Systems
Abstract
Present day machines and processes incorporate embedded
control, i.e., they are continuous physical systems controlled by
discrete digital processors. The complexity of these systems
with the increased demands on their reliability motivate the need for
adding monitoring and fault isolation capabilities in the embedded
processors. This paper develops monitoring, prediction, and fault
isolation methods for complex dynamic systems affected by abrupt
faults. The transient behavior in response to those faults
is exploited in a qualitative framework, using parsimonious topological
systems models developed in the bond graph framework.
Predicted transient effects of hypothesized faults are captured in the
form of signatures that specify future behavior for the fault with
higher order time-derivatives. The dynamic effects of faults are analyzed
by a progressive monitoring scheme till feedback
effects modify the initial transients significantly, and
the detection mechanisms have to be suspended in favor of steady state
analysis. This methodology has been successfully applied to monitoring
of the secondary sodium cooling loop of a fast breeder reactor.
The zipped up
postscript version of this paper is 337526 bytes.