Exhaust Analyser for Simplified Emissions Testing on Heavy Duty Vehicles

Sammanfattning: Over the years the regulations on emissions from heavy duty vehicles have become stricter. Emission measurements during development are therefore done by the manufacturers in order to check compliance in an early stage. This is a time demanding process due to complicated installation and operation of the test equipment. Therefore a simplified concept for replacing such equipment was evaluated and a prototype was designed capable of measuring NOx concentration, exhaust volume flow and CO2 concentration together with reading on board diagnostic messages over CAN in order to include additional truck sensory data. This report describes the development process and contains modular tests of the prototypes separate modules as well as a whole systems test against Horiba OBS-2200, a portable emissions measurement system, in a truck. The results from the tests were that NOx concentration, exhaust volume flow, CO2 concentration and NOx accumulated mass showed good correlation with the references used. The prototype system achieved a coefficient of determination, R2 value, of 0.988 for the NOx mass flow compared to the reference and a total error of less than 7% of accumulated NOx mass.