limit and operate at its borderline knock limit when it is knock limited.
During a cold start, the closed-loop controller operates
the engine at its maximum retard limit for fast catalyst light-off
while maintaining combustion stability at desired level. The
control strategy has been validated under steady state and slow
transient operations and the fast transient tests (such as FTP)
have not been completed yet. Combining this quasi-steady-state
oriented ignition timing control strategy with a feedforward
controller for improved transient performance remains a work
in progress.