Methodology of robust initialization of catalyst for consistent oxygen storage capacity measurement
US6631611B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 30, 2001 |
| Grant date | Oct 14, 2003 |
| Priority date | — |
| Expiry date | Nov 14, 2021 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/40
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A method of initializing the catalyst converter for monitoring the conversion efficiencies of a catalytic converter by measuring the oxygen storage capacity (OSC) of the converter. The measurement of the OSC indicates the degree of health of the converter. Under the same engine running conditions, the greater the OSC measurement, the healthier the converter. The catalyst needs to be set to either a rich state or a lean state prior to the measurement of its OSC time. This process is called catalyst state initialization. The catalyst has to be fully saturated from test to test in order to make consistent OSC measurements. This is through open loop fuel control by commanding a lean air to fuel ratio and then monitoring thepost-O2 sensor voltage until it falls below a calibrated value (e.g. 80 mV) indicating a lean state. The system continues to command a lean air to fuel ratio (e.g. 6%) for a calibrated duration of time (e.g. 3 seconds) to saturate the catalytic converter and drive it to a fixed saturation state. This ensures consistent OSC measurement in the second stage of the test.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.