Study on estimation method of vehicle NOx PM CO ₂ emissions factors applicable to local roadside

An estimation method is proposed to study the vehicle NO _x PM CO ₂ emissions factors. The estimation model using vehicle speed and vehicle power, is made with real world emissions data observed from an on-board measurement system. The on-board measurement system in the test vehicle measures vehicle positions by GPS, pictures of road infrastructures, traffic conditions, driver's operations, engine and vehicle dynamics, and NO _x,PM, CO ₂ emissions every 0.5 second. The PM emission is measured by smoke-meter using opacity method. Emissions per distance are obtained from emissions per driving time divided by a vehicle speed. Emissions per distance are employed as indexes of the pollution at roadside. Vehicle power includes vehicle weight, acceleration, and road grade, and are found to affect emission factors. Vehicle power (VP) model can estimate the local roadside emissions with higher accuracy as compared to Vehicle speed model.