Method for controlling the speed of an internal combustion engine supercharged by means of a turbocharger

A method for controlling an internal combustion engine (1) supercharged by means of a turbocharger (12) provided with a turbine (13) and a compressor (14); the control method comprises the steps of determining the current reduced mass flow rate (Q AHR ) of the compressor 14; determining a safety threshold (M max_turbo ) of the reduced mass flow rate (Q AHR ), said safety threshold (M max_turbo ) delimits in the plane reduced mass flow rate / compression ratio the portion of the critical area closest to achieve sonic conditions; and imposing that the reduced mass flow rate (Q AH ) of the compressor 14 is lower than the safety threshold (M max_turbo ) of the reduced mass flow rate (Q AHR ).