Motorola Corporation

Bruce A Church

Kevin J Bush

Darren A Schumacher

David Frankowski

Michael A Badalament

The catalyst control method of the invention continuously estimates a level of oxygen stored by a catalyst within a catalytic converter. The estimated oxygen stored by the catalyst is compared to a predetermined threshold and positive or negative deviations in the oxygen amount from the threshold is determined. When a positive deviation from the threshold amount is detected, the air/fuel ratio flowing into an engine (16) is decreased. Correspondingly, when a negative deviation is detected, the air/fuel ratio flowing into the engine (16) is increased. The amount of oxygen stored by the catalyst is determined by analyzing signals from a first gas sensor (28) positioned upstream from a catalytic converter (34) and a second gas sensor (30) positioned downstream from the catalytic converter (34). An engine control unit (10) integrates an expression for the mass flow rate of excess oxygen into the catalytic converter (34). Engine control unit (10) applies a change in air/fuel ratio to maintain the oxygen level on the catalyst within the catalytic converter (34) at a desired level.

Method for controlling the level of oxygen stored by a catalyst within a

A method for monitoring the performance of a catalytic converter (34) computes the oxygen storage capacity and desorption capacity of a catalyst within the catalytic converter (34). An engine control unit (10) receives mass flow rate information of air from a mass air flow rate sensor (12) and an injector driver (24), and receives electrical signals from an upstream exhaust gas sensor (28) and a downstream exhaust gas sensor (30). The engine control unit (10) calculates normalized air fuel ratios for the exhaust gas entering and leaving the catalytic converter (34) and performs numerical integration to determine the oxygen storage capacity and oxygen desorption capacity of the catalyst in the catalytic converter (34). The calculated oxygen storage and desorption capacities of the catalyst are compared with threshold values to determine the performance of the catalytic converter (34).

Method for monitoring the performance of a catalytic converter

A method and system for fuel delivery to an engine (400) measures when an exhaust gas sensor (413) is in a non-lit-off condition and when the exhaust gas sensor is in a lit-off condition. A control device (409) estimates fuel puddle dynamics for an intake system of the engine when the exhaust gas sensor is in the lit-off condition, and adapts (511) an open-loop fuel parameter table (229) dependent on the estimated fuel puddle dynamics. The control device (409) adjusts fuel delivery to the engine dependent on the fuel puddle dynamics when the exhaust gas sensor is in the lit-off condition, and adjusts fuel delivery to the engine dependent on the open-loop fuel parameter table (229) when the exhaust gas sensor is in the non-lit-off condition.

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Dearborn, MI, United States of America

Bruce A Church