Abstract:
An active control approach to air vehicle design can significantly expand the flight envelope and improve vehicle
performance characteristics. In some cases it can be attained by implementing the aerodynamically unstable
configuration or expanding operation at flight regimes with dynamic instability, which are then purposely stabilized
by the flight control system. An important issue in stabilization of unstable dynamics is connected with the size of the
controllability region, which is the set of all states of the aircraft dynamics that can be stabilized by some realizable
control action. This region is bounded because of nonlinear actuator constraints, and its size can be considered as
a measure for allowable level of external disturbances. In this paper an algorithm based on convex optimization
technique is proposed for computation of the controllability region of an unstable linear system under amplitude
and rate control constraints. Examples of the controllability region analysis for an aeroservoelastic airfoil system
and unstable aircraft dynamics are presented to illustrate the capabilities of the proposed algorithm.
Description:
This output describes an approach based on geometrical and optimisation principles that resulted in efficient software tools for computation of null controllability region of unstable dynamical systems. The software toolset, “Stabcalcs” has been created and tested on several flight dynamics applications and delivered to DERA/QinetiQ Ltd. within Computational Framework for flight clearance applications (in 2002-2003, DERA/QinetiQ Ltd Technical Manager Yoge Patel, yoge@bbsr.co.uk). The research was sponsored by QinetiQ Ltd.
