Patent ID: 6167868
Filing Date: 2001-01-02
Classification: F02P,Y02T

Abstract:
A method for determining ignition angles for individual cylinders in a multicylinder internal combustion engine, which comprises the steps of: adjusting shift values (ZW.sub.1 [KF.sub.1 (z)]) for families of characteristics (KF.sub.1 (z)) for individual cylinders in a first adaptation loop, in a ""late"" direction when engine knocking occurs and in an ""early"" direction when engine knocking ceases, based on an invariable ""global"" basic family of characteristics (KF.sub.B) dependent on load (L) and engine speed (n) and associated with all of the cylinders (z); globally shifting by a global shift value (ZW.sub.2) in the ""late"" direction or back in the ""early"" direction, in a second adaptation loop, when a magnitude of the adjusted ignition angle (ZW.sub.1), averaged over all of the cylinders, of the first adaptation loop exceeds a predetermined maximum value (ZW.sub.1max) or is less than a predetermined minimum value (ZW.sub.1min) at an operating point P(n, L); initiating a third adaptation loop when the internal combustion engine is stopped; using the shift values (ZW.sub.1 [KF.sub.1 (z)]) of the families of characteristics (KF.sub.1 (z)) for individual cylinders in the first adaptation loop, the global shift value (ZW.sub.2) in the second adaptation loop and the families of characteristics and values in the third adaptation loop from a previous running of the engine in the third adaptation loop to form new shift values (ZW.sub.3 [KF.sub.3 ]) for a global family of characteristics (KF.sub.3) and shift values (ZW.sub.3 (z)) for individual cylinders, and storing in a non-volatile manner in the third adaptation loop; and using the values after the engine is started again to form shift values (ZW.sub.B [KF.sub.B (z)]) for new ""basic families of characteristics"" (KF.sub.B (z)) for individual cylinders, and commencing ignition angle determination and knocking control in the new running of the engine using the first and second adaptation loop.