Patent Document ID: 4831992
Application ID: 07123147
Patent Flag: 1

Claim One:
1. Method for compensating for a tank venting error occurring in an adaptive learning system for metering the required fuel quantity to an internal combustion engine, the method comprising the steps of: determining said fuel quantity by means of a closed loop control wherein an actual value is evaluated (lambda control) and wherein open loop precontrol quantities stored in a first memory are taken as a basis which are also corrected by means of an adaptive learning process likewise using said actual value in an averaged form supplying a fuel flow to the intake region of the engine supplementary to said metered fuel quantity, said fuel flow resulting from an intermediate container (active charcoal filter) which takes up fuel vapor from the tank to thereby regenerate said container; switching over between closed tank venting and open tank venting phases, the latter leading to the supplementary fuel flow while at the same time maintaining the adaptive learning from lambda control for both operating conditions in such a manner that second precontrol quantities are established which are related to the disturbing quantities occurring during said open tank venting; storing said second precontrol quantities in a separate memory function; and, switching between the respective stored learned values for each change between basic adaptation phase and tank venting adaptation phase.