Browse Publications Technical Papers 1999-01-3323
1999-09-28

Real-Time Air/Fuel-Ratio Control in a Small SI Engine Using the Ionic Current Signal 1999-01-3323

Experiments were conducted on a small SI engine with the objective to investigate the relationship between air/fuel-ratio and the ionic current signal measured across the spark plug electrodes. The propane-operated, single-cylinder engine has been equipped with sensors to monitor its operating conditions and a CDI ignition system with a built-in ionic current sensing circuit.
More than 50 features of the ionic current signal have been examined in a preliminary analysis. Three features of the cycle-averaged signal (signal peak, signal integral in a crank angle window around the peak position, signal amplitude after a preset delay) were found to correlate reasonably well with air/fuel-ratio for the full range of operating conditions. After an evaluation of cycle-to-cycle variations of these features, simple algorithms for an application of the ionic current - mixture strength relationship are introduced.

SAE MOBILUS

Subscribers can view annotate, and download all of SAE's content. Learn More »

Access SAE MOBILUS »

Members save up to 18% off list price.
Login to see discount.
Special Offer: Download multiple Technical Papers each year? TechSelect is a cost-effective subscription option to select and download 12-100 full-text Technical Papers per year. Find more information here.
We also recommend:
TECHNICAL PAPER

Thin Film Semiconductor NOx Sensor

800537

View Details

TECHNICAL PAPER

A Study on the Transient Knock Control in a Spark-Ignition Engine

981062

View Details

TECHNICAL PAPER

Knock Signal Conditioning Using the Discrete Fourier Transform and Variable Detection Window Length

2007-01-1509

View Details

X