Internal exhaust gas recirculation control in an internal combustion engine

An automotive electronic control unit (14) for an internal combustion engine (1) comprising at least one cylinder (2) provided with at least one intake valve (3) and at least one exhaust valve (6), and a variable intake and/or exhaust valve actuation system (9). The electronic control unit (14) is programmed to control the variable valve actuation system (9) so as to obtain an internal exhaust gas recirculation through the intake and exhaust valves (3, 6) and to control the internal exhaust gas recirculation based on a mathematical model that models the fluid-dynamic behaviour of an intake or exhaust valve (3, 6) as if this was a nozzle (11).