| 摘要 |
In one aspect of the present invention, an apparatus for analyzing a plurality of events of an internal combustion engine is provided. A crankshaft sensor monitors the rotational position of the crankshaft and responsively produces a crankshaft pulsetrain. A cylinder pressure sensor senses the pressure produced in the engine cylinder and responsively produces a cylinder pressure signal. A memory device stores previously calculated values representing engine cylinder volumes at predetermined crankshaft positions. A microprocessor determines the start of combustion for an occurring engine cycle in response to a cylinder pressure signal magnitude, P2, at a current crankshaft position being equal or greater than the relationship: P1(V1/V2)n where, P1 equals the cylinder pressure corresponding to a previous crankshaft position, V1 equals cylinder volume corresponding to the previous crankshaft position, V2 equals the cylinder volume corresponding to the current crankshaft position, and n equals a predetermined polytropic value. Advantageously, the start of combustion is determined prior to the next occurring engine cycle. |
