Spark ignition engine control strategies for minimising cold start fuel consumption under cumulative tailpipe emissions constraints

This paper proposes a methodology for minimising the fuel consumption of a gasoline fuelled vehicle during cold starting. It first takes a validated dynamic model of an engine and its aftertreatment reported in a previous study (Andrianov, Brear, & Manzie, 2012) to identify optimised engine control strategies using iterative dynamic programming. This is demonstrated on a family of optimisation problems, in which fuel consumption is minimised subject to different tailpipe emissions constraints and exhaust system designs. Potential benefits of using multi-parameter optimisation, involving spark timing, air–fuel ratio and cam timing, are quantified. Single switching control policies are then proposed that perform close to the optimised strategies obtained from the dynamic programming but which require far less computational effort.