A current design objective of the automotive engineer is to control engine for minimizing fuel consumption for a given level of exhausts emission. The need to achieve the best possible control has motivated the application of the mathematical optimization technique to this problem. Therefore a procedure has been developed for establishing optimum engine performance, in term of fuel consumption and exhaust emission constraints, as a function of air-to-fuel ratio and spark advance.
The features of the procedure are:
(ⅰ) it is based on mathematical engine model,
(ⅱ) it is based on solving a nonlinear programming problem on primary domain with inequality constraints,
(ⅲ) the results of the optimization are used to develop control that can be implemented on a vehicle,
(ⅳ) the trade off analysis between fuel consumption and emission is developed, and
(ⅴ) when emission constraint is decreased, the trend of combustion temperature is obtained.
This study describes the procedure to determine suboptimal controls for a fuel injected spark ignition engine under warm-up operating conditions.
