The recent development of diesel engine fuel injection systems
has been dominated by how to manage the degrees of freedom that
common rail multi-pulse systems now offer. A number of production
engines already use four injection events while in research, work
based on up to eight injection events has been reported.
It is the degrees of freedom that lead to a novel experimental
requirements. There is a potentially complex experimental program
needed to simply understand how injection parameters influence the
combustion process in steady state. Combustion behavior is not a
continuum and as both injection and EGR rates are adjusted,
distinct combustion modes emerge.
Conventional calibration processes are severely challenged in
the face of large number of degrees of freedom and as a consequence
new development approaches are needed.
Our paper will describe the background to a project formulated
to investigate the application of Model Predictive Control (MPC) to
a Caterpillar C6.6 diesel engine. We outline an innovative
experimental facility developed for Rapid Control Prototyping (RCP)
for both air and fuel path using Field Programmable Gate Array
(FPGA) technology. This utilizes a Drivven FPGA injector driving
system coupled with National Instruments™ (NI) hardware (PXI,
CompactRIO) and LabVIEW 8.5 software. A detailed review is
presented of the development stages from an initial single-cylinder
open-loop fuel path control system through to a full-authority
6-cylinder injection system which replaces the Engine Control Unit
(ECU).
The original ECU fuel path control algorithms have been
re-written in LabVIEW Real-Time (RT) to emulate the original ECU
function. Drivven's CalVIEW is used for supervisory control and
to manage engine maps over a local area network link with the NI RT
environment. Two novel techniques are explored for integrating
MathWorks™ Simulink-based controllers through NI's Simulation
Interface Toolkit. Results demonstrate the control of exhaust
temperature using MPC.