Patent ID: 7270115

Claim:
A method for the pressure regulation of an accumulator fuel injection system for an internal combustion engine ( 1 ) having a common rail from which pressurized fuel is supplied to the various combustion chambers of the engine via fuel injectors under the control of an electronic control unit, said method comprising the steps of: determining a first actual rail pressure (pCR 1 (IST)) from a measured rail pressure (pCR) via a first filter ( 13 ), calculating from a desired rail pressure (pCR(SL)) and the first actual rail pressure (pCR 1 (IST)) a first control deviation (dR 1 ), determining, by a high pressure controller ( 9 ), a volume flow (qV) depending on the first control deviation (dR 1 ), determining from the measured rail pressure (pCR) a second actual rail pressure (pCR 2 (IST)) via a second filter ( 14 ), and using overridingly the second actual rail pressure (pCR 2 (IST)) for the calculation of the control contribution of the high pressure controller ( 9 ) by calculating a first proportional coefficient (kp 1 ) for determining a P-component ( 20 ) of the high pressure controller ( 9 ) via a first characteristic line ( 15 ) depending on the second actual rail pressure (pCR 2 (IST)) and calculating supplementally a delayed action time (TV 1 ) for determining a D-component and a DT 1 component ( 22 ) of the high pressure controller ( 9 ) via a second characteristic line ( 16 ) depending on the second actual rail pressure (pCR 2 (IST)), wherein the first characteristic line ( 15 ) and the second characteristic line ( 16 ) have a stationary range (STAT) in which, independently of the value of the second actual rail pressure (pCR 2 (IST)) a constant first proportional coefficient (kp 1 ) and a constant first action delay time (Tv 1 ) are calculated and in the dynamic range (DYN) the first proportional coefficient (kp 1 ) and the action delay time (Tv 1 ) are calculated based on an ascending function.