디젤 엔진의 엔진 토크 제어를 위한 실시간 IMEP 추정 알고리즘 개발

Abstract

The indicated mean effective pressure (IMEP) is an indicator which represents the engine torque directly from the in-cylinder pressure. However, the calculation of IMEP requires a large number of cylinder pressure data acquisition and long computation time. For this reason, an estimation method of IMEP with less number of cylinder pressure data acquisition and computation time is needed for real-time combustion control. In this study, we proposed the IMEP estimation algorithm using difference pressure. The difference pressure data during the expansion stroke is used to estimate the IMEP and defined the estimated IMEP value as IMEPdiff. The proposed IMEPdiff has high linear relationship with the real IMEP regardless of different engine operating conditions. Furthermore, the IMEPdiff method reduces the data acquisition of cylinder pressure by 75% and the computational load by 62% compared to the IMEP method which gives a great potential for the real-time estimation of IMEP.