Method for acquiring information about state of internal-combustion engine, involves producing quasi-stable signal from measuring signal, and acquiring information about state of engine by frequency analyze of quasi-stable signal

摘要

The method involves providing an internal-combustion engine (1) with a crankshaft (7) and cylinders (3), which cooperate with the crankshaft. Measuring signal of a state variable of the engine is determined in its operation. A measuring signal trend of the digital measuring signal is determined. Quasi-stable signal is produced from the measuring signal by adjusting the trend. Information about the state of the engine is acquired by frequency analyze of the quasi-stable signal. The trend is determined in such a manner that the measuring signal is approximated within an evaluation window.