Mass air flow engine control system with mass air event integrator

摘要

In an internal combustion engine control system, an electronic circuit accepts a non-linear analog signal from a Mass Air Flow (MAF) sensor and converts it to a digital signal by means of a linear or non- linear analog to digital (A/D) converter. The digital signal is then processed by a two- dimensional look-up table which includes corrections for the MAF sensor non-linearity and additional corrections for non- linearity of the A/D converter. This linearized MAF signal is then integrated or averaged to provide air mass per engine event or average mass air flow during an event. This circuit is useful in obtaining better accuracy in fuel management systems that use MAF sensors, particularly if variable valve control is included as part of the control system. The look up table and integrator can be easily implemented in a digital signal processor or microcontroller. The integrated or averaged MAF value can be used to control the various functions of the internal combustion engine in conjunction with other inputs (e.g., coolant level, engine speed or period, throttle position, etc.). An engine load factor representing the trapped mass or air in the combustion chamber is calculated by multiplying the MAF signal by the engine period. The load factor may be used to program ignition timing, control the air and fuel delivery systems, etc.