Method for detecting rotational speed
AssigneeSiemens Aktiengesellschaft
InventorsRalf Böhnig, Achim Przymusinski, Christian Stahl
Life of this patent
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Abstract
In a method for detecting rotational speed of an internal combustion engine (1), a sector wheel (4) which is driven by the internal combustion engine (1) is scanned, the run of a specific segment of the sector wheel is detected, the duration of said segment-run is measured and a rotational speed value is determined therefrom, the duration of the run a specific segment is re-measured, a relative variation between two consecutive segment-runs is determined and the rotational speed value is determined therefrom.
Claims20
A method for ascertaining the rotational speed of an internal combustion engine, comprising the steps of:
- a) scanning a sector wheel which is driven by the internal combustion engine,
- b) detecting a pass of a specific segment of the sector wheel and measuring the duration of this segment pass and ascertaining a rotational speed value therefrom,
- c) detecting a pass of a specific part of the segment repeatedly and measuring the duration of this part-segment pass and determining a relative variation of the duration of the part-segment pass between two consecutive passes of the specific part of the segment, and
- d) using the relative variation to correct the rotational speed value.
A method for ascertaining the rotational speed of an internal combustion engine, comprising the steps of:
- a) scanning a sector wheel which is driven by the internal combustion engine,
- b) measuring a pass of a specific segment of the sector wheel and evaluating a rotational speed value therefrom,
- c) measuring a pass of a specific part of the segment repeatedly and determining a relative variation of the duration of the part-segment pass between two consecutive passes of the specific part of the segment, and
- d) using the relative variation to correct the rotational speed value.
A arrangement for ascertaining the rotational speed of an internal combustion engine, comprising:
- a sensor for scanning a sector wheel which is driven by the internal combustion engine,
- means for detecting a pass of a specific segment of the sector wheel and measuring the duration of this segment pass and ascertaining a rotational speed value therefrom,
- means for detecting a pass of a specific part of the segment repeatedly, measuring the duration of this part-segment pass, and determining a relative variation of the duration of the part-segment pass between two consecutive passes of the specific part of the segment, and
- means for using the relative variation to correct the rotational speed value.
Dependencies are inferred from the claim text.