OPTIMAL FUEL AND GEAR RATIO CONTROL FOR HEAVY TRUCKS WITH PIECE WISE AFFINE ENGINE CHARACTERISTICS

The problem of minimizing fuel consumption for heavy trucks by optimal control of engine fueling and gear choice is studied. This is done by the use of a realistic truck model with prediction ability of fuel consumption. The effect of non-linearities in the engine characteristics is studied by the use of piece wise affine models. This is an extension to earlier work and allows for a more detailed study of how engine characteristics influence the optimal speed profile. The optimal choice of gear ratio is studied, and it is shown how the choice is affected by engine characteristics, especially by engine maximum torque characteristics.