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1. (WO2018130459) METHOD AND DEVICE FOR THE LOAD DIAGNOSIS OF A PARTICLE FILTER

Pub. No.:    WO/2018/130459    International Application No.:    PCT/EP2018/050229
Publication Date: Fri Jul 20 01:59:59 CEST 2018 International Filing Date: Sat Jan 06 00:59:59 CET 2018
IPC: F01N 9/00
F01N 11/00
F01N 3/021
F01N 3/023
F02D 41/00
Applicants: ROBERT BOSCH GMBH
Inventors: RITTER, Rouven
KUENNE, Robert
WEISSENMAYER, Simon
Title: METHOD AND DEVICE FOR THE LOAD DIAGNOSIS OF A PARTICLE FILTER
Abstract:
The invention relates to a method and a device, in particular a diagnostic unit for load diagnosis of a particle filter as a component of an exhaust gas cleaning system in the exhaust train of an internal combustion engine. Said method involves the evaluation of dynamic pressure profiles upstream and downstream of the particle filter. According to the invention, a frequency analysis is performed, and, in particular with higher frequencies, information about the load state of the particle filter is deduced from a transfer function of the particle filter as compared with a reference transfer function for an unloaded particle filter by making a comparison with stored reference values. Alternatively, even with only one pressure sensor, a load diagnosis can be performed by using the integral over the difference between the amplitudes of the currently measured frequency response and a reference frequency response. It is thus possible to use inexpensive pressure sensors that can provide a reproducible soot load diagnosis despite drift, for example due to ageing.