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Continually increasing the maximum specific power output of engines used in military vehicles is vital to maintaining a battlefield advantage. An enabling technology for power optimization on existing engine architectures is advanced engine control based on real-time feedback control of the combustion. An engine equipped with intelligent controls and multi-fuel capable components has been used to demonstrate power improvements based on feedback control of the fueling by means of in-cylinder pressure measurements. In addition to optimized power output for the engine, the technology suite provides the capability to utilize both standard diesel fuel and alternatives such as jet fuel, biodiesel, or any mixture. A cylinder-balancing algorithm adjusts the fueling to achieve even power distribution between cylinders for improved performance and durability, or to operate all cylinders at the cylinder pressure limit when maximum power is required.

This paper discusses the design and control of a two-stage electro-hydraulic camless Variable Valve Actuation (VVA) system designed for gasoline engines that encompass a wide rpm range. The VVA portion of each engine valve assembly in the system consists of two miniature pilot valves, a proportional valve, a compound engine valve actuator and an engine valve return mechanism. The design and proper control of these devices allow for variable valve timing, lift, duration, seating velocity and flank velocity. This flexibility enables an array of combustion strategies. Many of these strategies (such as Miller cycle operation, cylinder and valve deactivation, etc.) have been tested on fired engines that have been redesigned to incorporate the VVA system. Test results for both bench and fired engines running in a dynamometer cell are presented. These results indicate the current level of controllability of the system and the power consumed by the system in a variety of test conditions.