Ford Global Technolgoies, LLC

Ahmed Abdelaziz Omara

Douglas R Hamburg

John Edward Bradley

Richard E Soltis

Eleftherios M Logothetis

Active adaptive bias for closed loop air/fuel control system

A three-way catalyst model ( ) and a method for modeling the dynamic response of a three-way catalyst that divides the catalyst response into sub-regions ( ) . A sub-model ( ) is constructed that represents each sub-region ( ) . Each sub-model ( ) is assigned unique attributes at which the sub-model is activated. The attributes are based on the system parameters and states. The states may be either continuous or discrete and define a hybrid state space. A larger or smaller number of sub-regions ( ) can be utilized based on the model's ( ) use and the accuracy desired for the model ( ).

Three-way catalyst model for an engine air-to-fuel ratio control system

A method of controlling the air-fuel ratio of an internal combustion engine having an exhaust passage including a catalytic converter. The method includes providing a first air-fuel ratio sensor upstream of the catalytic converter, and providing a second air-fuel ratio sensor downstream of the catalytic converter. A control module having an input connected to the first and second air-fuel ratio sensors and an output connected to actuators for controlling the engine is also provided. This establishes a first feedback loop including the first air-fuel ratio sensor and a second feedback loop including the second air-fuel ratio sensor. The method further includes detecting an output value of the second air-fuel ratio indicative of a rich or lean exhaust gas air-fuel ratio. In response to the output value, the system monitors the engine mass airflow, and controls the duration of air-fuel ratio of the engine as a function of the engine mass airflow.

Air-fuel ratio feedback control

An exhaust gas oxygen sensor (10) mounted in the exhaust stream of an engine includes a zirconia plate (14) mounted to two electrodes (16,18), covered with porous layers (20,22). The two porous layers (20,22) are designed to sense the two conditions of air/fuel mixture, lean and rich, by creating a delay in the sensing of the rate of transmission of oxygen through one of these layers (20,22), without the need for a voltage source pumping oxygen through the sensor. A heating element (60) can be used with the sensor to reduce the light-off time of the sensor. Also, a latch 52 can be used to modify the signal from the sensor to provide for a more conventional EGO signal.

Exhaust oxygen sensing

A method of operating an oxygen sensor in the exhaust stream of an engine. The oxygen sensor includes a zirconia plate (14) mounted to two electrodes (16,18), covered with porous layers (20,22). The two porous layers (20,22) are designed to sense the two conditions of air/fuel mixture, lean and rich, by creating a delay in the sensing of the rate of transmission of oxygen through one of these layers (20,22). The method includes flowing exhaust gas over the sensor, maintaining essentially no flow of current through the leads when the exhaust gas maintains a state of rich or lean air/fuel ratio, and sensing induced emf spikes between the leads as the exhaust gas stream transitions between rich and lean air/fuel ratios.

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Ann Arbor, MI, United States of America

Ahmed Abdelaziz Omara