ISBN 9783843951012

978-3-8439-5101-2, Reihe Regenerative Energien

Peter Schwanzer
Experimentelle Untersuchungen zur On-Board Überwachung von Partikelfiltern für den Einsatz an direkteinspritzenden Benzinmotoren

194 Seiten, Dissertation Technische Universität München (2022), Softcover, A5

Zusammenfassung / Abstract

This thesis deals with the development of a methodology for an improved on-board diagnosis of particulate filters in vehicles with gasoline direct injection (GDI) technology with regard to future emission legislations.

In order to comply with statutory particle number limits, particulate filters are used in the exhaust gas aftertreatment for GDI-engines.

The currently applied method for diagnostic purposes, a differential pressure sensor, will not be suitable for future legislations. Therefore, an on-board strategy with real-time ability shall be developed.

To achieve this, the application of novel sensor concepts has been investigated, namely electrostatic soot sensors (ePM sensor) and radio frequency antennas (RF sensor).

Due to the results of the ePM-sensors, no methodology for an on-board diagnosis based on an ePM sensor concept was made.

The RF sensor showed varying sensitivities for different soot and different quantities of volatile components in the filter element. The analysis of the oxidation processes showed that the regeneration of the

filter element is detected by the RF sensor. Furthermore, the stored amount of ash could be captured. Due to these findings, a concept for an improved on-board diagnosis strategy by means of an RF sensor concept was developed.

In the course of the work it turned out that a combined sensor concept consisting of a differential pressure

sensor and a RF sensor is most suitable. In a validation process, this sensor concept showed sufficient results concerning the detection capability of soot and ash loads as well as of the degree of damage of particulate filters. Especially for small amounts of ash, this sensor concept showed specific advantage.

Also, the determination of the current amount of soot in the filter element proved to be suitable. Regarding the detection of damages, the sensor concept convinces through a higher sensitivity.