Browse Publications Technical Papers 2007-01-1288
2007-04-16

Valve Event Detection Using Knock Sensor Signals 2007-01-1288

To make electrical or electro-hydraulic gas exchange valve actuators more economically feasible for the production of cam-less engines, it is desirable to achieve valve position information from existing engine sensors rather than to develop and install new sensors for each gas exchange valve. Time and frequency domain characteristics of acoustic (knock) sensor signals were analyzed using both cross-correlation and Fourier analyses to determine characteristics that indicate valve position. The time-domain signatures for valve events were found to be inconsistent from cycle to cycle and thus difficult to identify using cross-correlation techniques. Frequency content of the engine vibration as it varied with crankshaft angle was analyzed to find valve position dependent patterns. Analysis revealed a wideband signal that correlates to intake and exhaust valve closing events. Tests conducted using several different knock sensors indicate that reliable closing event information is contained within the resonant frequency of the particular sensor utilized. Several filtering schemes were implemented to maximize the coherence of the valve closing event signal. A narrow band-pass filter centered at the sensor's natural frequency provides a good means of valve closure detection using a reasonable number of engine cycles.

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

Combustion Chamber Deposit Flaking and Startability Problems in Three Different Engines

2003-01-3187

View Details

TECHNICAL PAPER

Development Highlights and Unique Features of New Chrysler V-8 Engine

510196

View Details

TECHNICAL PAPER

Air Velocity Measurements in Engines by Vortex Shedding

741057

View Details

X