Measurement Principle

Segment period acquisition

Fig 1: Segment Period Acquisition

Courtesy of BMW OF NORTH AMERICA, INC.

The acquisition of the segment period is performed through an angular range of 180° crank angle.

NC_CYL_NR is the number of cylinder.

The segment starts NC_MIS_PHA°CA before TDC.

To compute an engine roughness value for a 4 cylinder engine, n = 9 contiguous valid segments are required.