Author: Christopher Simon Beaverstock

Publisher:

Published: 2012

Total Pages:

ISBN-13:

A closely integrated Flight Control System (FCS) design is fundamental to the successful develop- ment of modern aircraft. The FCS must provide adequate control authority to the pilot operator, along with a robust systems design that provides sufficient reliability and performance to ensure ad- equate handling qualities throughout the operational flight envelope. Using feedback controllers, the static and dynamic characteristics can be augmented, ultimately to improve the performance. In- cluding feedback control into the conceptual design process can in many cases improve not only the static and dynamic performance, but the operational efficiency. Essentially, the stability requirements are relaxed, where the additional parameters supplied by the controller are used to recover the lost performance. Furthermore, this is bounded by the performance of the command-actuation system. Parameters such as rate and maximum actuation output limit the systems designs performance, as well as the system dynamics which modifies the response. This thesis considers the task of integrating classical control and systems design under a single design framework. It is shown that by expanding the design space parameters, the overall aircraft perfor- mance and efficiency can be improved. The intended application of these methods is for integration into the conceptual design phase, where commitment of resources is normally at its greatest. Prin- ciples of this thesis are embodied in the FCS design environment Flight Control Systems Designer Toolkit (FCSDT), a sub-component of the Computerised Environment for Aircraft Synthesis and In- tegrated Optirnisation Methods (CEASIOM) software framework developed by Simulation of aircraft Stability And Control (SimSAC), an European Union (EU) funded Framework 6 Program, of which the author was a part of the development team. It is hypothesised that the FCS topology, systems architecture and control design are intrinsically linked, and that modifying these concurrently can lead to an improved design. This is demon- strated using data for a Boeing 747-100 published by National Aeronautics and Space Adminis- tration (NASA), selected due to the wealth of data and information available. Furthermore, with multiply-redundant surfaces and varying response and control power characteristics, provides a non- trivial example for FCS design. The NASA model was used to investigate static and dynamic per- formance across the operational ftight envelope. FCSDT was then used to explore the interaction between the topology and systems design whilst integrating feedback control. Results show the pos- sible performance benefits of. and the system limitations on. the control system design.