In-cylinder pressure detection device and method for internal combustion engine, and engine control unit

摘要

An in-cylinder pressure detection device for an internal combustion engine, which is capable of detecting an in-cylinder pressure accurately without being adversely affected by changes in the atmospheric pressure even when the atmospheric pressure changes. An in-cylinder pressure sensor detects pressure within a cylinder as a detected in-cylinder pressure. An ECU estimates pressure generated in the cylinder during a non-combustion period as a motoring pressure. An atmospheric pressure sensor detects an atmospheric pressure (PA). The ECU corrects the motoring pressure according to the atmospheric pressure and identifies correction parameters such that the difference between the detected in-cylinder pressure detected during a compression stroke of the engine and the corrected motoring pressure becomes minimum, and corrects the detected in-cylinder pressure by the identified correction parameters, to thereby calculate an in-cylinder pressure.