타행 성능 분석을 이용한 NEDC 모드의 엔진 운전 조건 분석

For emission and fuel economy test, test vehicle should be installed on a chassis dynamometer and driven according to prescribed driving pattern such as New Euorpean Driving Cycle(NEDC) or Federal Test Procedure (FTP-75). Road load which is imposed to the test vehicle when it is operating on real load should be reproduced by the chassis dynamometer. For this, actual road load should be measured on a test vehicle and coastdown test is widely used method. Normally used coastdown test is to measure the times during deceleration under neutral gear and prescribed test condition. With accurate coastdown measurement results, vehicle driving pattern can be transformed to engine operation mode. For this mechanical efficiency of gear box should be measured for each gear. This study suggests new method to calculated engine operation mode with coastdown measurement under neutral and in-gear condition. And calculation results were compared with actually measured engine operation.