microprocessor-based engine control system

[David C. Allen]

The Bendix Corporation, Southfield, MI

http://patent.womplex.ibm.com/details?&pn10=US04242728

A method and apparatus for controlling the various functions of an internal 
combustion engine using a program controlled microprocessor having a memory 
preprogrammed with various control laws and associated control schedules 
receives information relating to one or more actual engine operating 
parameters such as manifold absolute pressure, throttle position, engine 
coolant temperature, air temperature, engine speed or period or the like. 
These parameters are sensed and then supplied to input circuits for signal 
conditioning and conversion to digital words usable by the microprocessor. 
The microprocessor system computes one or more digital words indicative of 
particular computer-commanded engine control operations and output 
circuitry responds to predetermined computer-generated commands and to the 
computed digital command words for generating corresponding pulse-width 
control signals for controlling such engine operations as fuel-injection, 
ignition timing, proportional and/or on-off EGR control, and the like. A 
fuel management control "limp home" circuit is also disclosed which will 
allow a vehicle to be driven for a short distance such as to a repair 
station or the like whenever the microprocessor-controlled fuel injection 
system fails to function properly.