Title:
APPARATUS AND METHOD FOR DIAGNOSIS OF CATALYST PERFORMANCE
Document Type and Number:
WIPO Patent Application WO1999023372
Kind Code:
A3
Abstract:
A method and apparatus that converts time-resolved sensor signals into frequency domain signals using Fast Fourier Transforms and power spectral densities. A signal, as a means to assess catalyst performance such as a signal based on sensing oxygen concentration in motor vehicle exhaust in accordance with the present invention is in the time domain and has multiple components at different frequencies. The use of Fast Fourier Transforms isolates the various spectral density which arise from different frequency components of the complex time domain signal. The analysis has been found to be substantially independent of operating conditions. The power spectral density has found to be a precise indication of oxygen storage and release of the catalyst and catalyst performance. The catalyst performance can be signaled to the vehicle operator for on board diagnostics (OBD) of the catalyst.
Inventors:
KUMAR SANATH V
Application Number:
PCT/US1998/022496
Publication Date:
August 19, 1999
Filing Date:
October 23, 1998
Export Citation:
Assignee:
ENGELHARD CORP (US)
International Classes:
F01N11/00; (IPC1-7): G01N33/00; F02D41/14; F01N7/00; B01D53/94; B01J37/02
Domestic Patent References:
| WO1995035152A1 | 1995-12-28 | |||
| WO1996017671A1 | 1996-06-13 |
Foreign References:
| US5207107A | 1993-05-04 | |||
| US5313791A | 1994-05-24 | |||
| US5157919A | 1992-10-27 | |||
| US5341642A | 1994-08-30 |
Other References:
PATENT ABSTRACTS OF JAPAN vol. 097, no. 007 31 July 1997 (1997-07-31)
PATENT ABSTRACTS OF JAPAN vol. 097, no. 012 25 December 1997 (1997-12-25)
PATENT ABSTRACTS OF JAPAN vol. 018, no. 164 (M - 1579) 18 March 1994 (1994-03-18)
PATENT ABSTRACTS OF JAPAN vol. 016, no. 500 (P - 1437) 15 October 1992 (1992-10-15)
MEITZLER, A.: "Application of Exhaust-Gas-Oxygen Sensors to the study of Storage Effects in Automotive Three-Way Catalysts", SOCIETY OF AUTOMOTIVE ENGINEERS, INC. PAPER SAE800019, 1980, pages 14 - 21, XP002094829
M. SIDERIS: "Methods for Monitoring and Diagnosing the Efficiency of Catalytic Converters", May 1998, ELSEVIER, AMSTERDAM, XP002094830, 022910
PATENT ABSTRACTS OF JAPAN vol. 097, no. 012 25 December 1997 (1997-12-25)
PATENT ABSTRACTS OF JAPAN vol. 018, no. 164 (M - 1579) 18 March 1994 (1994-03-18)
PATENT ABSTRACTS OF JAPAN vol. 016, no. 500 (P - 1437) 15 October 1992 (1992-10-15)
MEITZLER, A.: "Application of Exhaust-Gas-Oxygen Sensors to the study of Storage Effects in Automotive Three-Way Catalysts", SOCIETY OF AUTOMOTIVE ENGINEERS, INC. PAPER SAE800019, 1980, pages 14 - 21, XP002094829
M. SIDERIS: "Methods for Monitoring and Diagnosing the Efficiency of Catalytic Converters", May 1998, ELSEVIER, AMSTERDAM, XP002094830, 022910
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