System for controlling powertrain components to achieve fuel economy goals

摘要

A system for controlling a vehicle driveline in a fuel economy manner, in one embodiment, includes a control computer that operates to determine a number of engine load / engine speed limit conditions as functions of brake specific fuel consumption (BSKV) contours based on an engine output characteristic map it defines a range U for undesired engine operation. As long as at least one of the gear ratios of the vehicle transmission is engaged for the engine, the control computer works in such a way that it keeps or effects engine operation outside the U range. In another embodiment, the control computer operates to define a contour from a substantially zero engine load to an engine load that is substantially full load, the contour preferably corresponding to a fuel economy path from engine operating conditions with no load to full load. In the case of gear shift transmissions, the control computer works in such a way that it controls transmission shift points around the contour. In the case of continuously variable transmissions, the control computer works by changing its effective transmission ratio in order to keep the motor operation on the contour or around it. In both cases, fuel economy operations can be optimized.