Abstract: A physics-based charge temperature model to calculate a charge air temperature for an automobile vehicle includes multiple variables. The multiple variables include: a first variable defining an engine speed of an engine defining revolutions per minute of a crankshaft of the engine; a second variable defining a cam position; a third variable defining an engine coolant temperature; a fourth variable defining an air intake temperature; a fifth variable defining an engine air flow; and a sixth variable defining a firing fraction of the engine. A controller provides multiple lookup tables. The controller controls operation of the engine using the multiple variables and data in the multiple lookup tables to calculate a charge air temperature for individual intake strokes of at least one cylinder of the engine.

Abstract: A method for compressor surge detection to enable model based air estimation includes determining if an intake air compressor pressure ratio is within a predetermined surge pressure range. Then the differences between mass air flow sensor signals measured at a start and finish of each count of a predetermined string length counter when the compressor pressure ratio is within the predetermined surge pressure range. Next, a transition is made to an air mass estimation model output signal from a mass air flow sensor signal when a sum of the air flow differences is greater than a predetermined compressor surge threshold.

Abstract: A method for compressor surge detection to enable model based air estimation includes determining if an intake air compressor pressure ratio is within a predetermined surge pressure range. Then the differences between mass air flow sensor signals measured at a start and finish of each count of a predetermined string length counter when the compressor pressure ratio is within the predetermined surge pressure range. Next, a transition is made to an air mass estimation model output signal from a mass air flow sensor signal when a sum of the air flow differences is greater than a predetermined compressor surge threshold.