Scania Cv Ab (Publ)

Mikael Hanson

Fredrik Swartling

Mikael Persson

Mats Jennische

When controlling an engine provided with Variable Turbine Geometry (VTG), the VTG is closed to a maximally acceptable closed position without endangering the VTG when performing an up-shift. The VTG is kept in such a position during the gear shift which, allows for a quick retardation of the engine speed.

Method of controlling a VTG engine

In a method and a system for controlling the Variable Turbine Geometry (VTG) of a combustion engine during up-gear shift, the VTG is opened based on a prediction when exhaust gas pressure is stabilized. During up-gear shift the VTG is closed to a closed position () to build an exhaust gas pressure and reduce engine speed, and a parameter from which the engine acceleration can be deduced is recorded. The VTG is determined to be opened to an open positioning response to the recorded parameter and a target engine speed of the up-gear shift (), and the VTG is opened at a time corresponding to said determination to reduce the exhaust gas pressure (). Hereby the up-gear shift can be made in a short time and at smooth operational conditions.

Gearshift control method

When controlling an engine having a Variable Turbine Geometry (VTG) the VTG is closed some predicted time period before an up-gear shift is performed. This is advantageous because when the gear shift begins the engine breaking is already maximized and full engine brake can be obtained during the entire gear shift operation.

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Årsta, Sweden

Mikael Hanson