Gearshift control method
AssigneeScania CV AB (publ)
InventorsFredrik Swartling, Mikael Hanson
Life of this patent
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Abstract
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 (301) 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 (303), and the VTG is opened at a time corresponding to said determination to reduce the exhaust gas pressure (305). Hereby the up-gear shift can be made in a short time and at smooth operational conditions.
Claims16
A method of controlling a Variable Turbine Geometry (103) of a combustion engine (101) powering a motor vehicle (10) during an up gear shift, characterized by the steps of:
- closing (301) the Variable Turbine Geometry to a maximally permitted closed position for building an exhaust gas pressure,
- recording a parameter from which the engine acceleration can be calculated,
- determining (303) when the Variable Turbine Geometry should be opened based on at least said recorded parameter and a target engine speed for the up gear shift, and
- opening (305) the Variable Turbine Geometry at a time corresponding to said determination to reduce the exhaust gas pressure.
A control system for controlling the position of a Variable Turbine Geometry (103) of a combustion engine (101) powering a motor vehicle (10) during an up gear shift, characterized by:
- means (107) for closing the Variable Turbine Geometry to a maximally permitted closed position for building an exhaust gas pressure,
- means (107) for recording a parameter from which the engine acceleration can be calculated,
- means (107) for determining when the Variable Turbine Geometry should be opened based on at least said recorded parameter and a target engine speed for the up gear shift, and
- means (107) for opening the Variable Turbine Geometry in relation to said determination.
A computer program product for controlling the position of a Variable Turbine Geometry (103) of an internal combustion engine (101) powering a motor vehicle (10) during an up gear shift, characterized in that the computer program product comprises program segments which when executed on a computer for controlling the Variable Turbine Geometry cause the computer to perform the steps of:
- controlling (301) the Variable Turbine Geometry to a maximally permitted closed position for building an exhaust gas pressure,
- recording a parameter from which the engine acceleration can be calculated,
- determining (303) when the Variable Turbine Geometry should be opened based on at least said recorded parameter and a target engine speed of the up gear shift, and
- controlling (305) the Variable Turbine Geometry to open at a time corresponding to said determination to reduce the exhaust gas pressure.
Dependencies are inferred from the claim text.