Development of a Configurable Electronic Engine Control Computer 950010
To meet the need for a flexible electronic controller that is easily configured to meet different operating requirements, a general purpose Electronic Control Unit (ECU) has been developed. The ECU reads engine operating parameters from the sensors and generates output signals to the fuel injectors in response to those parameters as determined by the control software. Multiple signal path options allow a genenc printed circuit board to be configured for different applications by populating alternate components as needed for the specific input and output requirements. Unused component mounting pads are left blank. This ECU has been applied to a variety of advanced electro-hydraulic fuel injection systems for gasoline, diesel, compressed natural gas, propane, and dual-fuel applications.
The configuration flexibility and signal processing power of the ECU make it an appropriate choice for both small volume development projects and OEM or after-market use. Various engine control software strategies including speed and load governing, overspeed protection, and skip-fire have been demonstrated. Generic control software is customized to satisfy the specific requirements of each engine application.
Engine calibration parameters are displayed and can be modified, via a personal computer, during engine tests. These include fuel delivery, timing, and sensor calibration maps. Once the parameters are proven to be satisfactory, a permanent Erasable Programmable Read Only Memory (EPROM) is programmed using the PC. This re-calibration can be performed in the field by an application engineer or test technician.
The ECU was designed for the heavy duty engine environment and to permit two different configurations - standard air cooling or optional fuel cooling.
Environmental tests have been performed to verify reliability - shock, vibration, high and low temperatures, electromagnetic compatibility, liquid splash, salt spray, and power supply transient voltages.