Reconfigurable flight control

Proceedings of the Institution of Mechanical Engineers, Part G:

2008

This article presents a fault tolerant flight control system using multiple model adaptive control (MMAC). To apply this method to the aircraft, model reference adaptive control is extended to a linear discrete-time multiple-input multiple-output system. Multiple models can be determined by various flight conditions with respect to possible aircraft fault situations. In this article, the damages of control effectors are considered as aircraft faults. The aerodynamic coefficients of fault model are derived by a damaged control surface area. In the MMAC, how to select a proper fault model and how to switch into the selected model are significant issues. The conventional mode switching method, however, has a tendency to make the system fluctuate because of frequent mode switching, and therefore may deteriorate the performance of the aircraft. In this study, the modified adaptive mode switching scheme and new decision logic are proposed to improve the adaptiveness in the transient state dynamics of system. Numerical simulations are performed for a linear discrete-time aircraft model to validate the effectiveness of the proposed method.

Section: Model Reference Adaptive Controlmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Fault tolerant flight control system design using a multiple model adaptive controller

Jung

Proceedings of the Institution of Mechanical Engineers, Part G:

2008

2006 American Control Conference

“…The solution to the generalized linear regression with intercept is developed in [8], and is summarized here in Theorem 1.…”

Section: Augmented Regressionmentioning

confidence: 99%

“…Theorem 1 The explicit closed-form solution to the linear regression with intercept (1) is determined in [8]. The minimum variance parameter estimate iŝ…”

Section: Augmented Regressionmentioning

confidence: 99%

Adaptive and reconfigurable flight control using feed-forward action

Nelson¹,

Pachter

2006

Indirect adaptive control for reconfigurable flight control is advocated. Specifically, on-line static system identification using a moving window/batch estimation, is used. The ensuing linear regression is augmented with an intercept to address the effects of trim change associated with the occurrence of a control surface failure. Parameter estimate information is used to adjust the inner loop's control gains and a command derived from the intercept estimate is fed forward to retrim the aircraft automatically. The tracking performance of this automatic retrimming method which uses system identification, surpasses the conventional approach of exclusively relying on integral action for automatic retrimming. The novel adaptive and reconfigurable flight control system successfully handles a horizontal tail control surface loss.

“…2,3 Recently, a new reconfigurable flight control system was suggested to cope with abrupt changes caused by partial wing loss as well as faults in control surfaces by adopting Model Reference Adaptive Control (MRAC) and Automatic Supervisory Adaptive Control (ASCA). [4][5][6][7][8][9] Such damaged aircraft experience abrupt and violent changes of aerodynamics as well as physical characteristics such as weight, center of gravity (CG), and moment of inertia (MOI). Therefore, understanding the effects of the aircraft's damage on the flight dynamic characteristics is crucial for designing a damage-tolerant control system.…”

Section: Introductionmentioning

confidence: 99%

Analysis of partial wing damage on flying-wing unmanned air vehicle

Ahn

Proceedings of the Institution of Mechanical Engineers, Part G:

et al. 2013

This article investigates the effect of asymmetric wing damage on flight dynamic characteristics of a flying-wing single motor unmanned air vehicle. To construct a six degree-of-freedom model of the damaged aircraft, a flying-wing type unmanned aerial vehicle is designed, and the wind tunnel test for damaged configurations is performed to identify the change of aerodynamic coefficients. The changes of mass, center of gravity, and moment of inertia are also calculated for each damage configuration with CATIA. The changed trim states are calculated depending on the severity of damage, and the movements of poles in longitudinal/lateral-directional flight modes are examined to evaluate the change of the dynamic stability and performance. Numerical simulations and eigenvalue analyses are performed to investigate the altered flight dynamics. It is verified that an asymmetrically wing-damaged unmanned air vehicle shows a sluggish roll behavior with longitudinal instability, and the result of this study can be a cornerstone for the future research on reconfigurable flight controller design against aircraft damage.