On-Line Parameter Estimation Issues for the NASA IFCS F-15 Fault Tolerant Systems
Mario G. Perhinschi, Marco Lando, Luca Massotti, Giampiero Campa Marcello R. Napolitano, Mario Luca Fravolini *Department of Mechanical and Aerospace Engineering, West Virginia University, Morgantown, WV 26506/6106, -Department of Aeronautical Engineering, Polytechnic of Torino, 10129 Torino, Italy. +Department of Electronic and Information Engineering, University of Perugia, 06100 Perugia, Italy.
Development of a Simulation Environment to Support Aircraft Health Management Education
A simulation environment is developed at West Virginia University (WVU) to support current efforts for the integration into the curriculum of engineering aspects related to aircraft health management. The objective is to provide undergraduate and graduate aerospace engineering students with advanced knowledge and skills in the area of modeling, detection, evaluation, monitoring, and accommodation of abnormal aerospace systems operation within an experiential and active learning environment. A set of dedicated simulation tools is presented, which integrates PC-based simulation with the WVU 6-degrees-of-freedom motion-based flight simulator. Several types of failure of various aircraft sub-systems (actuators, sensors, structure, engine) as well as adverse atmospheric conditions and abnormal human pilot conditions are modeled and implemented. Parameter identification algorithms, failure detection schemes, and fault tolerant control laws are implemented for demonstration and analysis purposes. The use of the simulation environment is illustrated through a classroom simulation experiment designed to put into evidence the dynamic signature of aerodynamic control surfaces failures.
Phase characterisation of simulated high burn-up UO2 fuel
Abstract To determine the lattice constant variation with burn-up and the oxidation behaviour at high temperatures, simulated UO2-spent fuels with burn-ups up to 200 GWd tM−1 were prepared by cold pressing and sintering and characterised by X-ray diffraction analysis and thermogravimetry. The fcc-lattice parameter of the sintered samples determined at room temperature, showed a continuous decrease with the simulated burn-up. During oxidation the conversion of the simulated fuels to the (U,FP)4O9 and (U,FP)3O8-type phases was strongly delayed when the simulated burn-up exceeded 80 GWd tM−1. Also, at high burn-ups (>100 GWd tM−1), large fractions of the (U,FP)4O9-type phase remained untransformed to (U,FP)3O8 after prolonged exposure to air at 950–1000°C. This suggests a marked widening of the (U,FP)4O9-phase field when the amount of substituted uranium atoms exceeds values of about 8%.