On-board vehicle emissions measurement system with a sensor and a computer system

An on-board vehicle pollutant emissions measurement system including a vehicle comprising an internal-combustion engine and an aftertreatment system for exhaust gas of the engine and the on-board system including at least one sensor downstream from the aftertreatment system of the vehicle and a computer system for determining the pollutant emissions of the vehicle by implementing a vehicle model, a model of a type of the engine and an aftertreatment model of the vehicle, the vehicle model relating at least one of position, altitude and speed of the vehicle to torque and to speed of the engine, the engine model relating the torque and the speed of the engine to emissions at an outlet of the engine, and the aftertreatment model relating the emissions at the outlet of the engine to the emissions at of an outlet of the aftertreatment system, wherein the models of the computer system are responsive to a signal coming from the at least one sensor to determine pollutant emissions of the vehicle by modifying parameters of the models to align output of the models with physical values obtained by the at least one sensor.