Patent ID: 7366603
Filing Date: 2008-04-29
Classification: F02D

Abstract:
1. A position decoding method for a four-stroke internal combustion engine, comprising the steps of: producing a CAM signal based on rotation of a camshaft of said engine, the CAM signal having a series of four width-encoded pulses per cycle of said engine; producing a CRANK signal based on rotation of a crankshaft of said engine, the CRANK signal having a series of pulses and a sync feature; defining an observation window with respect to a first pulse transition of said CAM signal, said observation window extending for a predefined angle of crankshaft rotation; producing a first indication based on whether a second pulse transition occurs in said CAM signal during said observation window and a second indication based on whether said sync feature occurs in said CRANK signal during said observation window, whereby a different combination of said first and second indications occurs for each of the width-encoded pulses of said CAM signal; and decoding the width-encoded pulses of said CAM signal based on said first indication and said second indication.