Sensor Needs for Control and Health Management of Intelligent Aircraft Engines

NASA and the U.S. Department of Defense are conducting programs which support the future vision of “intelligent” aircraft engines for enhancing the affordability, performance, operability, safety, and reliability of aircraft propulsion systems. Intelligent engines will have advanced control and health management capabilities enabling these engines to be self-diagnostic, self-prognostic, and adaptive to optimize performance based upon the current condition of the engine or the current mission of the vehicle. Sensors are a critical technology necessary to enable the intelligent engine vision as they are relied upon to accurately collect the data required for engine control and health management. This paper reviews the anticipated sensor requirements to support the future vision of intelligent engines from a control and health management perspective. Propulsion control and health management technologies are discussed in the broad areas of active component controls, propulsion health management and distributed controls. In each of these three areas individual technologies will be described, input parameters necessary for control feedback or health management will be discussed, and sensor performance specifications for measuring these parameters will be summarized. INTRODUCTION NASA and the U.S. Department of Defense are pursuing revolutionary technology advances to achieve the realization of intelligent aircraft engines, which will be self-diagnostic, selfprognostic, self-optimizing, and mission adaptable. These engines will require advanced Propulsion Control and Health Management (PCHM) [1] capabilities including sensors, diagnostics and prognostics, adaptive/active controls, and integrated controls and diagnostics. PCHM is a technology investment that will directly support the NASA goal to enable a safer, more secure, more efficient, and environmentally friendly air transportation system [2]. The objectives of NASA include: 1) decrease the aircraft fatal accident rate and the vulnerability of the air transportation system to threats, and mitigate the consequences of accidents and hostile acts; 2) protect local and global environmental quality by reducing aircraft noise and emissions; and 3) enable more people and goods to travel faster and farther, with fewer delays. PCHM technology also plays a prominent role in the Department of Defense Versatile Affordable Advanced Turbine Engine (VAATE) Program which is focused on achieving a 10 times improvement in the combined areas of engine capability and affordability [3]. The VAATE program balances the emphasis on capability (performance, operability, survivability and robustness), and affordability (development, production and maintenance costs). The VAATE Intelligent Engine focus area spans diverse technologies, including active control and engine health management, to achieve a self-optimizing, selfdiagnosing, mission-adaptable propulsion system. Sensing technology is the foundation upon which a PCHM system is based as it is relied upon to accurately collect the data required for engine control and health management. Today’s aircraft propulsion systems are typically equipped with a suite of control sensors (temperatures, pressures, rotor speeds, etc.), the outputs of which are used as inputs by the engine control logic. Additionally, engines are typically equipped with various sensors for health monitoring purposes and cockpit displays. These can include lubrication and fuel system sensors (pressure and flow), accelerometers, and gas-path instrumentation for performance monitoring purposes. NASA/TM—2004-213202 1 Inlet Fan Comp. Combustor