Method and apparatus for controlling the operation of an internal combustion engine

摘要

The operation of an internal combustion engine in the region of its lean-running limit is controlled on the basis of engine roughness as measured by an inductive crankshaft transducer. Its periodic signal gates the counting in a digital down-counter, from a pre-set number, at a frequency proportional to r.p.m. The content of the down counter is counted up or down in a subsequent up-down counter depending on the value of its own most significant bit which indicates the algebraic sign of the phase comparison between the transducer frequency and the r.p.m.-proportional frequency. Two digital integrating stages eliminate effects due to constant engine acceleration. A decoder supplies a control signal to a final control element for fuel, air or exhaust control.