NOx Emission of a Correlation between the PEMS and SEMS over Different Test Modes and Real Driving Emission

Abstract

The aim of this study is to verify the reliability of NOx emissions measured using Smart Emissions Measurement System (SEMS) equipment in comparison with the NOx emissions measured using certified Portable Emissions Measurement System (PEMS) equipment. The SEMS equipment is simple system, and it is less expensive than the PEMS equipment, as it comprises an On-Board Diagnostics (OBD) signal from the test vehicle and a NOx sensor. The SEMS equipment based on low-cost sensors has an advantage of building big data, but there are insufficient previous studies comparing of NOx emissions with certified the PEMS equipment. Therefore, this study is important in verifying the suitability of the SEMS equipment by comparing the NOx emissions measured by the various test modes and RDE using the two types of equipment. To analyze the correlation between the PEMS and SEMS equipment, the advanced diesel vehicle was equipped with the two types of equipment to simultaneously measure NOx emissions. After installing the equipment on the test vehicle, it was conducted under various test modes in the laboratory and the Real Driving Emission (RDE) test to verify the correlation of NOx emissions measured by the SEMS equipment. The correlation analysis for the NOx emissions measured by the PEMS and SEMS equipment under various test conditions and the RDE test indicated that the slope of the NOx emissions was approximately equal to 1, and the coefficient of determination was 0.9 or higher. Based on these test results, it was concluded that NOx emissions measured by the PEMS and SEMS equipment are highly similar.

Effect of Tampering on On-Road and Off-Road Diesel Vehicle Emissions

“…The CO 2 was calculated based on the fuel carbon-hydrogen ratio and the fuel flow rate. Studies have shown that the results are well comparable with PEMS [41].…”

Predicting instantaneous engine-out NOx emissions in a real-driving vehicle data scenario

“…In the case of NO x emissions, although they are not as accurate as PEMS, readily available production NO x sensors are considered as a valuable source of information. 59,60 The benefits and applications of vehicle emissions models are clear and have been widely addressed. In the foreseen connected framework with on-board emission monitoring requirements, 61,62 assessing whether realworld data alone (i.e.…”

“…In the case of N O x emissions, although they are not as accurate as PEMS, readily available production NO x sensors are considered as a valuable source of information. 59,60…”