Gm Global Technolgoy Operations, Inc.

Yong Xu

Wenbo Wang

David S Mathews

Jian Lin

Vincent A White

Tameem K Assaf

Michael R Grimes

Ronald Joseph Kubani

Douglas J Moening

Richard H Clutz

David L St Pierre

A diagnostic system for an engine includes an oxygen detection module, a timing module and a control module. The oxygen detection module receives an oxygen signal from an oxygen sensor that detects an oxygen level in an exhaust system of the engine. The oxygen signal has N rich states and M lean states, where N and M are integers greater than or equal to 1. The timing module determines a rich period that the oxygen signal is in at least one of the N rich states and determines a lean period that the oxygen signal is in at least one of the M lean states. The control module detects an asymmetrical error with the oxygen sensor based on a comparison between the rich period and the lean period.

Asymmetrical oxygen sensor diagnostic and degradation compensation systems

An engine system that compensates for disturbances in a crankshaft signal is provided. The system includes: an error module that computes an error between an ideal period and an actual period of a crankshaft signal; a correction factor module that determines a correction factor based on the error; and a compensation module that applies the correction factor to the actual period of the crankshaft signal.

Method of crank signal disturbance compensation

A rough road detection system includes an engine speed module, a feature space module, a normalization module, and a rough road module. The engine speed module generates an engine speed signal based on a crank signal. The feature space module generates a feature space signal based on the engine speed signal. The normalization module generates a normalized signal. The normalized signal is based on the feature space signal and a normalization value that varies in accordance with the engine speed signal. The rough road module determines whether a rough road condition exists based on the normalized signal.

Rough road detection system

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Ann Arbor, MI, United States of America

Yong Xu