Aalborg University
Parameter Robust FDI using a Set-Valued Approach
Target group
This project proposal addresses primarily students at the department of control
engineering at Aalborg University on the 8th and 9th Semester.
Scope
Before the Fault Detection and Isolation (FDI) can be used in real-life industrial
application, the issue of robustness with respect to, for example, disturbances and
parameter perturbations must be considered. One way to handle the robustness
with respect to parameter perturbations is the so-called set-valued approach. The
scope of this project is to investigate possibilities with this approach on a
centrifugal pumps system.
Objective
The first step in using the set-valued approach is to setup a model of the system
including parameter variations. This could be a linearized model, working around
an operating point, or a nonlinear model. In many applications the pump is running
around a constant operating point, meaning that a linearized model wound be
preferable.
The second step is to use the set-valued approach to do parameter robust fault
detection. Finally, the set-valued approach should be further developed to handle
the robust fault isolation problem (here, the proposers of the project has some
ideas).
Description
I real-life applications the parameters of the system model is only known to some
extent. This is due to for example parameter variations during normal operation, or
simplifications in the model. To guarantee correct fault detection, and avoid faults
alarms these parameter variations must be taken into account. One way to due that
is the set-valued approach.
In the set-valued approach an interval model of the system is derived. In this
interval model the parameter variations describes and intervals in the parameter
space. These parameter intervals are then mapped into a set of possible residual
values, as it is shown in Figure 1. If 0 is not inside this interval it is known that a
fault has happened in the system. If 0 is inside the interval it is not known if a fault
has happened or the derivation from zero is just due to parameter variations.
2
r

+ yi
0
r
1
yi
Figure 1: The map from the parameter space to a set of possible residual values.
13-02-2016
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Aalborg University
The tasks of the project are, firstly to develop a model of the centrifugal pump
system including an interval model describing parameter variations. This model
should secondly be used to derive a fault detection scheme based on the set-valued
approach. Finally, the set-valued approach should be further developed to include
the fault isolation problem.
The developed algorithm should be tested on a test setup, which is placed at
Aalborg University. Below a sketch of the test setup is shown.
dSpace /
Simulink
VLT
Motor
Pump
Figure 2: Test setup
It is possible to simulate 6 different faults on this test setup. Meaning that the
developed algorithms can be tested against 6 different fault scenarios.
The students choosing this project will gain knowledge of the following.

The general FDI problem, including disturbances decoupling techniques.

The used of a set-valued or interval approach of parameter robust FDI.

Centrifugal pumps and electrical machinery, where are widely used in
industry.
Resources
A test setup, with a centrifugal pump, can be provided at the Aalborg University if
necessary.
Contact
Roozbeh Izadi-Zamanabadi
Carsten Skovmose Kallesøe
13-02-2016
Mail:
riz@control.aau.dk
Phone:
???
Mail:
ckallesoe@grundfos.com
Phone:
+45 8750 4632
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