Abstract: An internal-combustion engine, comprises at least one cylinder, at least one intake pipe and at least one exhaust pipe associated to the cylinder, at least one intake valve and at least one exhaust valve, which control passage through the intake and exhaust pipes, wherein there are provided first sensor device(s) for detecting the temperature in the intake pipe, second sensor device(s) for detecting the pressure in the intake pipe, third sensor device(s) for detecting the engine r.p.m., and fourth device(s) for detecting or calculating the temperature in the exhaust pipe. An electronic control unit pre-arranged for receiving the signals at output from the first second and third sensor device(s) calculates the amount of fresh air taken in by the engine on the basis of a mathematical model that is of general applicability and that, in particular, is applicable irrespective of the technological implementation specifically used for a system for variable valve actuation with which the engine can be provided.

Abstract: In an internal-combustion engine, comprising at least one cylinder, at least one intake pipe and at least one exhaust pipe associated to the cylinder, at least one intake valve and at least one exhaust valve, which control passage through said intake and exhaust pipes, there are provided first sensor means for detecting the temperature in said intake pipe, second sensor means for detecting the pressure in said intake pipe, third sensor means for detecting the engine r.p.m., and fourth means for detecting or calculating the temperature in said exhaust pipe. An electronic control unit pre-arranged for receiving the signals at output from said first, second and third sensor means calculates the amount of fresh air taken in by the engine on the basis of a mathematical model that is of general applicability and that, in particular, is applicable irrespective of the technological implementation specifically used for a system for variable valve actuation with which the engine can be provided.

Abstract: A method for determining the stroke end instant of the shutter during the deactivation phase of an electro-valve. The method comprises the following steps: assessment of nominal deactivation time and deduction from time of the assessed instant in which the deactivated shutter reaches the stroke end position, application of an appreciable current flow through the coil during shutter motion, after coil deactivation, adjusted in a time range comprising the assessed nominal deactivation instant, acquisition of a convenient number of current samples, identification of two adequate interpolation curves for acquired data, which approximate the development of the samples acquired before and after the instant in which the shutter reaches the stroke end, respectively, determination of the intersection point of the interpolation curves, from which the intersection instant can be inferred, and identification of shutter stroke end instant with the intersection instant.

Abstract: The invention describes a method for determining the stroke end instant of the shutter during the deactivation phase of an electro-valve. The proposed method comprises the following steps: assessment of nominal deactivation time and deduction from said time of the assessed instant in which the deactivated shutter reaches the stroke end position, application of an appreciable current flow through the coil during shutter motion, after coil deactivation, adjusted in a time range comprising said assessed nominal deactivation instant, acquisition of a convenient number of current samples, identification of two adequate interpolation curves for acquired data, which approximate the development of the samples acquired before and after the instant in which the shutter reaches the stroke end, respectively, determination of the intersection point of said interpolation curves, from which the intersection instant can be inferred, identification of shutter stroke end instant with said intersection instant.

Abstract: A method and apparatus of controlling supercharge pressure following rapid acceleration includes the steps of generating a pressure signal related to the value of the supercharge pressure of an engine; generating a reference signal related to a desired supercharge pressure value; generating a correction signal related to a time derivative of the pressure signal; generating an acceleration output signal as a function of a linear combination of the pressure signal, the reference signal and the correction signal; and supplying the acceleration output signal as a control signal.

Abstract: An electronic system (1) for controlling the injection pressure of a fuel injection system (4) wherein a pump (8) supplies fuel at high pressure to a rail (17) presenting a number of outlets (19a, 19b, 19c, 19d) communicating with respective injectors (21a, 21b, 21c, 21d). The injection system (4) presents a pressure regulator (24) interposed between the outlet (8a) of the pump (8) and the inlet (17a) of the rail (17), and controlled by a drive signal (U(z)) generated by a regulator circuit (50); the regulator circuit (50) is supplied with a digital error signal (Err(z)) representing the difference between a signal (Pmis(z)) generated by a pressure sensor (38) in the rail, and a signal (Prif(z)) representing an optimum reference pressure; and the regulator circuit (50) presents a transfer function R(z) of type (1), where "a", Kc are calculated numeric coefficients, and z is a digital variable.