In a control device for an internal combustion engine, when a target pre/post compressor pressure ratio calculated by a target pre/post compressor pressure ratio calculation part is more than a turbine-limit-time pre/post compressor pressure ratio calculated by a turbine-limit-time pre/post compressor pressure ratio calculation part, an upper limit of the target pre/post compressor pressure ratio is limited by the turbine-limit-time pre/post compressor pressure ratio, and a change rate of the target pre/post compressor pressure ratio is limited by a change rate limit value during a change rate limitation period after upper limit limitation processing starts, thereby preventing the target pre/post compressor pressure ratio from being suddenly fluctuated by a sudden fluctuation in a compressor passage flow rate, and suppressing the occurrence of the over rotation of the turbine and the control hunting.

Methods and systems are provided for controlling boost pressure in a staged engine system comprising a turbocharger and an upstream electric supercharger. In one example, a method may include accelerating an electric supercharger to choke the flow of air to the engine in the event of turbocharger overboost.

A method is provided for modeling the compressor speed of a turbocharger, and includes determining the temperature difference across the compressor, determining the mass flow through the compressor, and calculating a compressor speed value as a function of the temperature difference across the compressor and the mass flow.

A method for controlling an inlet-adjustment mechanism in an air inlet for a compressor so as to switch the mechanism between open and closed positions for adjusting a flow area of the inlet. The method includes an algorithm for determining when the inlet-adjustment mechanism is in a failure mode. In accordance with the method, when the operating point on the compressor map is on the high-flow side of a threshold line at which the inlet-adjustment mechanism is switched from one position to the other, a measured speed or pressure ratio is compared to a theoretical value for the speed or pressure ratio based on a compressor map for the open position of the mechanism. If the measured value differs from the theoretical value by more than a predetermined tolerance, a failure mode is indicated.

A method is provided for modeling the compressor speed of a turbocharger, and includes determining the temperature difference across the compressor, determining the mass flow through the compressor, and calculating a compressor speed value as a function of the temperature difference across the compressor and the mass flow.

A control device (10) for a supercharging system for supplying compressed intake air to an engine (6) includes: an engine controller (10A) including an engine signal input part (10A1) and an engine control part (10A2) configured to control an operational state of the engine and to compute a target boost pressure of a supercharger (4); and a turbo controller (10B2) including a turbo signal input part (10B1) and a turbo control part (10B2) configured to compute a margin of the supercharger. The control device is configured to compute a target boost-pressure corrected value by correcting the target boost pressure in accordance with a magnitude of the margin computed by the turbo control part, and to control a boost-pressure control unit (12) so that the boost pressure of the supercharger reaches the target boost-pressure corrected value.

A supercharging device for an engine is provided, which includes a supercharger provided to an intake passage of the engine, an actuator configured to drive the supercharger, and a controller including a processor configured to control the actuator to drive the supercharger when an operating state of the engine is in a given supercharging range, and to stop the supercharger when the operating state is in a non-supercharging range. The controller causes the actuator to forcibly drive the supercharger in the non-supercharging range when a temperature of the supercharger is lower than a preset temperature, and prohibits the forcible drive of the supercharger when a rotation speed of the supercharger during the forcible drive of the supercharger is lower than a preset rotation speed.

A supercharged internal combustion engine is provided that is capable of introducing EGR gas into an intake passage on an upstream side relative to a compressor. When a required WGV opening degree is less than a lower limit value WGVmin in a case in which introduction of EGR gas is started under a situation in which the temperature of an EGR valve is less than or equal to a predetermined value X1, the WGV opening degree is controlled during a protection time period T3 after introduction of EGR gas starts by using the lower limit value WGVmin as the required WGV opening degree.

Systems, methods, and computer-readable storage media for emulating a turbocharger speed sensor of a turbocharger in an engine. A processor executing the method can receive data from a plurality of sensors in the engine, wherein the data includes: an exhaust manifold pressure of the engine; an exhaust mass flow of the engine; and an injection angle of fuel in the engine. The processor enters the data as inputs into an artificial neural network, where the artificial neural network is trained to receive the inputs and output a speed of the turbocharger of the engine, then receives an output from the artificial neural network which is the speed of the turbocharger.

In a control device for an internal combustion engine, when a target pre/post compressor pressure ratio calculated by a target pre/post compressor pressure ratio calculation part is more than a turbine-limit-time pre/post compressor pressure ratio calculated by a turbine-limit-time pre/post compressor pressure ratio calculation part, an upper limit of the target pre/post compressor pressure ratio is limited by the turbine-limit-time pre/post compressor pressure ratio, and a change rate of the target pre/post compressor pressure ratio is limited by a change rate limit value during a change rate limitation period after upper limit limitation processing starts, thereby preventing the target pre/post compressor pressure ratio from being suddenly fluctuated by a sudden fluctuation in a compressor passage flow rate, and suppressing the occurrence of the over rotation of the turbine and the control hunting.