Coldstart Control Analysis Using Dynamic Programming

The need to reduce the negative effects of automotive hydrocarbon emissions on human health has drawn attention to the coldstart period of a combustion engine. The coldstart phase consists of the first few minutes of operation of the engine and generates a large percentage of the total cumulative hydrocarbon emissions. The focus of this study is on developing strategies to reduce emissions without adding extra hardware components to the engine. The control strategy was based on Dynamic Programming. The problem of minimizing hydrocarbon emissions was set up in such a way that optimality could be analyzed for different time horizons. The results explain the tradeoffs involved in the coldstart problem. The resulting optimal control strategy can be used to define tracking profiles in a Dynamic Surface Controller developed previously.