A Demonstration of a Retrofit Architecture for Intelligent Control and Diagnostics of a Turbofan Engine

Evaluation of an Outer Loop Retrofit Architecture for Intelligent Turbofan Engine Thrust Control

“…2 The difficulty in implementing a direct thrust control system arises because thrust is not directly measurable and the relationship between fan speed and thrust changes with engine deterioration. If engine deterioration could be estimated, thrust could be reconstructed fairly accurately, but the limited number of sensors on a typical commercial engine makes the deterioration estimation problem underdetermined.…”

“…In this context, worst case is defined as the largest degradation-induced shift in either direction-5% reduction in efficiency and flow capacity of each component in the cold section of engine (fan, LPC, HPC) in one case, and 5% shift in efficiency (reduction) and flow capacity (increase) of each component in the hot section of engine (HPT, LPT) in the other. 2 Again, normalization is performed by dividing the data gathered at each operating point by the nominal thrust level at that operating point. Figure 5 demonstrates the relative size of the estimation error to the magnitude of the degradation-induced shift.…”

“…A conceptual architecture of this type was developed and the outer loop thrust control was demonstrated to reduce pilot workload in cases where the engines suffered from unequal levels of deterioration, by automatically balancing thrust. 2 The current paper focuses on the interaction between the outer loop control portion of the architecture and a single engine, in order to evaluate the effectiveness of the approach in the presence of uncertainty of the forms typically encountered: model mismatch, nonlinearities, noise, etc.…”

Intelligent Situational Control of Small Turbojet Engines

“…This has been pursued by many authors in the recent decades bringing advances in the field of control theory and computational intelligence into control systems of gas turbine engines in order to increase their efficiency and reliability without the need of structural optimizations of the engine's components as comprehensively described in a survey of intelligent technologies for application in gas turbine engines [21,22].…”

“…However, most of them base their results and conclusions solely on simulations like [19,27,30,34] or present only conceptual designs like [21,22,25]. Application of methodologies from the field of computational intelligence can also be seen together with interconnection of diagnostic and control systems [21,22,27], which can further enhance the control system's reliability and efficiency.…”