Consistent Performance With Fuel Found in Theater: Real-Time Fuel Adaptation With Cylinder Pressure Based Combustion Control

Cylinder Pressure Monitoring (AVL CYPRESS^™) is a technology which provides closed-loop feedback to enable real-time control of combustion in a compression ignition engine. This makes it possible to adapt to the fuel ignition quality and energy density by adjusting the main injection quantity and the placement of the injection events. The engine control system can thus detect fuel quality and adapt the combustion phasing quickly and robustly – and without any prior knowledge of fuel properties. By using a cylinder pressure sensor(s), the engine controller will be able to map the development of the apparent rate of heat release (ARHR) and the mass fuel burn curve - which provides good thermal efficiency correlation. The cylinder pressure map detects the combustion event and the feedback controller adjusts the start of injection to maintain the combustion event at the desired crank position. The cylinder pressure sensor allows for accurate measurement of the power produced. By varying the volume of fuel in each injection shot the controller actively manages the engine power and noise signature with different fuels (e.g. DF-2, JP-8, JP-5, etc.). The initial concept for this approach was derived from AVL’s suite of hardware and software tools developed for base engine combustion research and development. This technology is now licensed to major OEMs and is in production vehicles in Europe. Results of AVL CYPRESS performance on military grade fuels is presented which demonstrate consistent torque performance within 1% regardless of varying fuel properties.