Patent ID: 6796169
Filing Date: 2004-09-28
Classification: G01M

Abstract:
A cylinder identifying system for an internal combustion engine, comprising:crank angle signal generating means for generating a plurality of crank angle pulse signals in correspondence to rotation angles of a crank shaft of said internal combustion engine; cylinder identifying signal generating means for generating cylinder identifying pulse signals corresponding to cylinders, respectively, of said internal combustion engine during rotation of a cam shaft arranged to rotate at a ratio of 1/2 relative to the rotation of said crank shaft; reference position detecting means for detecting reference positions on the basis of said crank angle pulse signals; cylinder identifying interval setting means for setting cylinder identifying intervals with reference to said reference positions; cylinder identifying means for identifying said individual cylinders on the basis of said cylinder identifying pulse signals in said cylinder identifying intervals; and operation state detecting means for detecting operation state of said internal combustion engine in a low rotation speed range and a high rotation speed range of said internal combustion engine, wherein said reference position detecting means includes: first detection processing means for effectuating a processing procedure of first performance specifications corresponding to said low rotation speed range; and second detection processing means for effectuating a processing procedure of second performance specifications corresponding to said high rotation speed range; operations of said first detection processing means and said second detection processing means being changed over with each other in dependence on the operation states of said internal combustion engine.