Model Based Diagnosis of the Intake ManifoldPressure on a Diesel Engine
Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesisAlternative title
Modellbaserad laddtrycksdiagnos för en dieselmotor (Swedish)
Stronger environmental awareness as well as actual and future legislations increase
the demands on diagnosis and supervision of any vehicle with a combustion engine.
Particularly this concerns heavy duty trucks, where it is common with long driving
distances and large engines. Model based diagnosis is an often used method in
these applications, since it does not require any hardware redundancy.
Undesired changes in the intake manifold pressure can cause increased emissions.
In this thesis a diagnosis system for supervision of the intake manifold
pressure is constructed and evaluated. The diagnosis system is based on a Mean
Value Engine Model (MVEM) of the intake manifold pressure in a diesel engine
with Exhaust Gas Recirculation (EGR) and Variable Geometry Turbine (VGT).
The observer-based residual generator is a comparison between the measured intake
manifold pressure and the observer based estimation of this pressure. The
generated residual is then post treated in the CUSUM algorithm based diagnosis
When constructing the diagnosis system, robustness is an important aspect. To
achieve a robust system design, four different observer approaches are evaluated.
The four approaches are extended Kalman filter, high-gain, sliding mode and an
adaption of the open model. The conclusion of this evaluation is that a sliding
mode approach is the best alternative to get a robust diagnosis system in this
application. The CUSUM algorithm in the diagnosis test improves the properties
of the diagnosis system further.
Place, publisher, year, edition, pages
2009. , 80 p.
Model Based Diagnosis, MVEM, Observer, CUSUM
Engineering and Technology
IdentifiersURN: urn:nbn:se:liu:diva-20852ISRN: LiTH-ISY-EX–09/4290–SEOAI: oai:DiVA.org:liu-20852DiVA: diva2:236573
Glashuset, Linköpings Universitet (Swedish)
Svärd, Carl, Ph.D. StudentWhalström, Johan, Ph.D. Student
Frisk, Erik, Associate Professor