METHOD FOR MEASURING EXHAUST GAS RECIRCULATION FLOW IN AN ENGINE SYSTEM, CONTROLLING EMISSIONS IN AN ENGINE SYSTEM, AND AN ENGINE SYSTEM

A method is provided for measuring exhaust gas recirculation (EGR) flow in. an engine system wherein turbo speed of a turbocharger, inlet pressure upstream of a compressor, boost pressure upstream of an engine, and engine intake temperature upstream of the engine are measured. Air mass flow into the engine system is calculated as a function of the turbo speed, inlet pressure, and boost pressure, exhaust mass flow is calculated as a function of the boost pressure, the engine intake temperature, volumetric efficiency of the engine, and engine size, and EGR flow is determined, by subtracting air mass flow from exhaust mass flow. A method for controlling emissions from an engine system, and an. engine system are also provided.