Normalizing oxygen storage capacity(OSC) for catalyst monitoring
AssigneeGM Global Technology Operations LLC
InventorsWenbo Wang, Richard B. Jess, David N. Belton
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Abstract
An oxygen storage capacity (OSC) monitoring system for a vehicle having a catalytic converter includes a control module that determines a measured OSC based on an inlet sensor signal (ISS) that is responsive to an oxygen content of exhaust flowing into the catalytic converter. The control module determines a normalization ratio based the measured OSC and determines a PASS/FAIL status of the catalytic converter based on the normalization ratio.
Claims23
An oxygen storage capacity (OSC) monitoring system for a vehicle having a catalytic converter, comprising:
- a first module that determines a measured OSC based on an inlet sensor signal (ISS) that is responsive to an oxygen content of exhaust flowing into said catalytic converter;
- and
- a second module that determines a normalization ratio based on said measured OSC and that determines a PASS/FAIL status of said catalytic converter based on said normalization ratio,
- wherein said second module determines said normalization ratio based on at least one of a best unacceptable OSC and a worst acceptable OSC, wherein said best unacceptable OSC is a predetermined maximum unacceptable OSC for said catalytic converter, and wherein said worst acceptable OSC is a predetermined minimum acceptable OSC for said catalytic converter.
A method of monitoring an oxygen storage capacity (OSC) in a vehicle having a catalytic converter, comprising:
- generating an inlet signal based on an oxygen content of exhaust flowing into said catalytic converter;
- determining a measured OSC based on said inlet signal;
- calculating a normalization ratio based on said measured OSC;
- determining a PASS/FAIL status of said catalytic converter based on said normalization ratio;
- comparing said normalization ratio to a threshold normalization ratio;
- and
- indicating a FAIL status via at least one module when said normalization ratio exceeds said threshold normalization ratio.
An oxygen storage capacity (OSC) monitoring system for a vehicle having a catalytic converter, comprising:
- a first module that determines a measured OSC based on an inlet sensor signal (ISS) that is responsive to an oxygen content of exhaust flowing into said catalytic converter;
- and
- a second module that:
- determines a normalization ratio based on said measured OSC;
- determines a PASS/FAIL status of said catalytic converter based on said normalization ratio;
- determines a compensated OSC based on said measured OSC and at least one of (i) a percentage of ethanol present in a fuel and (ii) a fuel trim average;
- and
- determines said normalization ratio based on said compensated OSC.
Dependencies are inferred from the claim text.