Calculation of the engine roughness values luts, fluts and dluts (%DMDLFB)

The engine roughness luts (angular acceleration) for each combustion is calculated from several temporarily consecutive segment times as follows:

Fig 1: Calculation Of Engine Roughness Luts

Courtesy of BMW OF NORTH AMERICA, INC.

The compensation time tkomp(n)  is made in the calculation for normal engine operation involving accelerations and decelerations.

dluts  is calculated by subtracting of luts values staggered by 360° CS: (one revolution of the crankshaft)

Fig 2: Calculation Of Engine Roughness Dluts

Courtesy of BMW OF NORTH AMERICA, INC.

For fluts  the cylinder-individual engine roughness values luts(cyl)  are filtered by means of a recursive low pass (fluts(cyl)): 

fluts(cyl)(i) = fluts(cyl)(i-1) + FFLUTN * (luts(cyl)(i) - fluts(cyl)(i -1))

i: camshaft revolutions

FFLUTN: filter constant