Signal drift compensating method for e.g. direct or indirect fuel injection type petrol or oil internal combustion engine, of automobile, involves attributing cylinder pressure filter signal at given instant to offset value at given instant

摘要

The method involves calculating a corrected cylinder pressure signal corresponding to a noise pressure cylinder signal measured by a cylinder pressure sensor at an instant. Difference between a value of a cylinder pressure filter signal at the given instant and an offset value at the preceding instant is calculated. The cylinder pressure filter signal at the given instant is attributed to offset value at the given instant when the difference is less than amplitude threshold or the preceding offset value at the preceding instant. An independent claim is also included for a system for compensating signal drift measured by a cylinder pressure sensor arranged in a combustion chamber of an internal combustion engine.