Patent ID: 6499342
Filing Date: 2002-12-31
Classification: F02D,G01M

Abstract:
In an internal combustion engine, a method of determining the final stopping position of said engine where said engine may have reversed its direction of rotation following shut off of the engine's ignition system during engine shut down, comprising the steps of:(A) generating a periodic crankshaft position signal having an amplitude and a frequency that vary as a function of the speed and rotational position of said crankshaft; (B) measuring the amplitude â€œAMPâ€  of said signal over an interval of time â€œTâ€  between each half wave of said position signal after said ignition system has been shut off; (C) generating a set of ratio values by dividing the amplitudes AMP measured in step (B) by the values of the corresponding time intervals T; (D) comparing successive ratio values generated in step (C) with a preselected constant value related to said stopping position of said engine, a change in the relationship of successive ones of said ratio values to said constant value indicating whether said engine has slowed down and continued in the same rotational direction or has stopped and reversed its rotational direction; (E) updating a record of the current rotational position of said crankshaft each time steps (C) and (D) are performed.