Technique for calculating a high-precision IMEP using a low-resolution coder and an optimized integration process

摘要

A method of calculating an effective mean pressure in an internal combustion engine, the method comprising: defining a sampling resolution for a series of sampling events, wherein the sampling resolution is an amount of crankshaft rotation between the sampling events defined by the geometry of a crankshaft position encoder; a volume matrix is calculated and stored, the volume matrix including a combustion chamber volume as a function of crankshaft position for each sampling event; Matrices for a first and a second volume-related variable are calculated and stored, wherein the volume-related variables include values for each crankshaft position that corresponds to the sampling resolution; wherein the first volume-related variable is defined by the equation: and wherein the second volume-related variable is defined by the equation: where k is the sample event number, n is a ratio of specific heats, Δ is the sample resolution, and V is the volume of combustion chamber volume matrix each sample event k is evaluated; the engine is run and a cylinder pressure reading is detected at each crankshaft position corresponding to the sampling resolution; ...