Inventors:
Ralph W. Carp - Newport News VA
Harold E. Weissler - Newport News VA
Paul R. Kudlaty - Newport News VA
Assignee:
The Bendix Corporation - Southfield MI
International Classification:
F02M 700
G06F 1546
Abstract:
A hybrid electronic control unit for regulating the air/fuel ratio of an internal combustion engine is disclosed. The electronic control unit is divided into two functionally distinct parts including an analog function generator and a digital function generator. The analog function generator receives analog signals to process efficiently by analog scaling, amplification, multiplication, and division while the digital function generator receives digital and logic inputs to process efficiently by addition, subtraction, and comparison. The analog function generator interfaces with the digital function generator by an analog signal from a D/A converter and other unconverted digital output signals from the digital function generator. Preferably, the analog function generator provides an open loop air/fuel ratio calibration based upon a speed density calculation including special condition corrections to the base calibration. Primarily, the digital function generator is a microprocessor implemented closed loop integral controller providing a closed loop correction signal to the open loop scheduler.