Patent ID: 7905214
Filing Date: 2011-03-15
Classification: F02D,G01M

Abstract:
1. A method for ascertaining the gas work W K performed by the cylinder pressure of a cylinder of an internal combustion engine on the piston of this cylinder, in which the cylinder pressure p is detected by a cylinder pressure sensor assigned to the cylinder, and the associated stroke volume V α is derived from a crankshaft sensor assigned to a crankshaft, and in which the gas work W K is determined from the areas formed by the cylinder pressure curve over the stroke volume V α , the method comprising the steps of: starting a cylinder-pressure-proportional integrator, which integrates the signals of the cylinder pressure sensor in a number of integrator runs selected as a function of a settable integrator capacitance dp, the integrator capacitance dp being set by presetting a lower and upper threshold value for the integrator value, during at least one of the integrator runs, upon reaching one of the threshold values, starting a new integrator run, at the beginning and end of which the current crankshaft angle α is detected, for each integrator run, determining the associated individual work dW determining the gas work W