Improved pilot training via bifurcation analysis and robust control for aircraft loss of control problems
08 May 2019-Vol. 233, Iss: 14, pp 5414-5427
TL;DR: A simulator for improved pilot training based on bifurcation and continuation techniques is presented and a robust control-based loss of control handling module is also presented for developing non-intuitive strategies for Loss of control prevention and recovery.
Abstract: Aircraft loss of control is one of the largest contributors to fatal accidents in the aviation environment. The unprecedented change in aircraft dynamics due to loss of control onset and the associ...
Citations
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03 Jan 2022
TL;DR: In this paper , a two-point boundary state problem is formulated for aircraft spiral recovery and a control law based on sliding mode control technique is designed for F-18 High Alpha Research Vehicle (HARV) to demonstrate the proposed work.
Abstract: Aircraft spiral profile is simulated in the present paper. Thereafter, control law based on sliding mode control technique is designed for aircraft spiral recovery. The F-18 High Alpha Research Vehicle (HARV) is considered to demonstrate the proposed work. The present problem is formulated as two-point boundary state problem, wherein, starting point is spiral state and end point is level-trim flight state. Both the reference points are taken from bifurcation analysis of aircraft dynamics. The controller stability for an applied control command is also proved. In the proposed control formulation, aircraft primary controls are derived in a closed-loop form. The chattering free response of control variables is achieved due to implemented power rate reaching law. The contributions of this paper lie in the control formulation, wherein altitude is controlled apart from spiral recovery. Also, the controller is able to achieve the same heading angle and altitude where the recovery attempt was initiated. Moreover, simulation results of the present paper show that the designed control law makes the wing-level flight by controlling the aircraft attitude followed by the altitude control to attain constant-altitude-level flight.
25 Mar 2022
TL;DR: In this article , different autonomous landing profiles are formulated and simulated, and the merits and demerits with respect to the practicality of implementation of these profiles are then discussed, and each landing profile has been demonstrated using sliding mode controller (SMC).
Abstract: In the present paper, different autonomous landing profiles are formulated and simulated. Generic landing is modelled first, wherein, approach and acquired runway heading is considered as same. The second-landing profile involves altitude hold when runway is not clear to land the aircraft. Expedited landing is the third profile modelled with a glide slope-maintained descent to reduce the ground distance required pre-touchdown. In either of the landing profiles, flare is kept the same. The merits and demerits with respect to the practicality of implementation of these profiles are then discussed. Each landing profile has been demonstrated using sliding mode controller (SMC). The asymptotic stability and finite-time proofs of the designed controller are shown using Lyapunov function. F-18 HARV aircraft is considered to test the efficacy of the formulated landing profiles. Expedited landing profile proposed here is a novel approach in which altitude descent gradient is maintained with helical descent path. Additionally, results of this approach show significant improvement in terms of possibility of initiating an unconventional and yet safe as well as economical method much nearer to the runway.
03 Jan 2022
TL;DR: In this paper , a sliding-mode control technique is used to stabilize the aircraft pitch, roll and heading angle and attains the desired attitude in finite time, and the simulation results show that the designed control law succeeds in achieving levelwing flight condition by controlling the aircraft attitude.
Abstract: Aircraft attitude in flat-spin motion is controlled in the present paper using sliding-mode control technique. The designed controller stabilizes the aircraft pitch, roll and heading angle and attains the desired attitude in finite time. In the proposed control formulation, aerodynamic controls namely elevator, aileron and rudder, are derived in a closed-loop form, and chattering free response of control variables is achieved due to the implemented power rate reaching law. This paper contributes to attitude control, even with perturbed inertial property and aerodynamic model of aircraft. Moreover, simulation results of the present paper show that the designed control law succeeds in achieving level-wing flight condition by controlling the aircraft attitude.
References
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08 Jan 2007
TL;DR: The state-of-the-art in the use of bifurcation and continuation methods for the analysis of aircraft trim and stability with a few illustrative examples are described.
Abstract: The bifurcation and continuation methodology has evolved over the last two decades into a powerful tool for the analysis of trim and stability problems in aircraft flight dynamics. Over the years, bifurcation methods have been employed to deal with a variety of problems in aircraft dynamics, such as predicting high angle of attack behavior, especially spin, and studying instabilities in rolling maneuvers. The bifurcation methodology has served as a tool for the design of flight control systems, and is promising to be a useful tool in the aircraft design, simulation, testing, and evaluation process. In the present paper, we describe the state-of-the-art in the use of bifurcation and continuation methods for the analysis of aircraft trim and stability with a few illustrative examples. Both the standard and extended bifurcation analysis procedures are discussed and typical results for instabilities in high-α flight and in inertia-coupled roll maneuvers are shown. This is followed by several problems in nonlinear flight dynamics where bifurcation and continuation methods have been fruitfully applied to yield effective solutions. Finally, the use of bifurcation theory to arrive at analytical instability criteria is demonstrated for the aircraft roll coupling and wing rock problems. 76 references have been cited in the text.
57 citations
"Improved pilot training via bifurca..." refers methods in this paper
...A state-of-the-art review on the use of bifurcation methods for aircraft trim and stability analysis is presented in Paranjape et al.(22) Pilots often rely on their intuitions to solve the LOC problem that they are going through....
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...A state-of-the-art review on the use of bifurcation methods for aircraft trim and stability analysis is presented in Paranjape et al.22 Pilots often rely on their intuitions to solve the LOC problem that they are going through....
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10 Aug 2009
TL;DR: In this paper, the authors examine how these nonlinearities affect the ability to control the aircraft and how they may contribute to loss-of-control, using NASA's Generic Transport Model.
Abstract: The majority of fatal aircraft accidents are associated with ‘loss-of-control’. Yet the notion of loss-of-control is not well-deflned in terms suitable for rigorous control systems analysis. Loss-of-control is generally associated with ∞ight outside of the normal ∞ight envelope, with nonlinear in∞uences, and with an inability of the pilot to control the aircraft. The two primary sources of nonlinearity are the intrinsic nonlinear dynamics of the aircraft and the state and control constraints within which the aircraft must operate. In this paper we examine how these nonlinearities afiect the ability to control the aircraft and how they may contribute to loss-of-control. Examples are provided using NASA’s Generic Transport Model.
56 citations
05 Nov 2002
56 citations
"Improved pilot training via bifurca..." refers background in this paper
...In Shah et al.12 and Cunningham et al.,13 efforts have been made to extend the training database beyond normal envelope by conducting extensive wind tunnel tests....
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...In Shah et al.(12) and Cunningham et al....
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TL;DR: The benefits of the proposed PRERL method is many fold: reducing reaching time, improving chattering alleviation and ensuring settling of the states at its final position with considerable improvement in speed of response.
Abstract: In Sliding Mode Control (SMC), the control action can be split into two regions- the reaching phase and the sliding phase. Considerable research attention has been given to improve the reaching time so as to best utilize the benefit of robustness property of sliding mode motion. Attention has also been on alleviating and/or eliminating chattering during sliding mode motion so that smooth control is obtained which will not hinder practical applications. Exponential Reaching Law (ERL) is one of the methods reported in the literature for alleviating chattering in sliding mode. This paper proposes a Power Rate Exponential Reaching Law (PRERL) whereby substantial improvement both in reaching time and chattering alleviation are achieved compared to ERL. With ERL, the states do not settle at its desired position due to high frequency low magnitude chattering, thus limiting its practical utility. This drawback has been overcome in the PRERL method. Thus the benefits of the proposed method is many fold: reducing reaching time, improving chattering alleviation and ensuring settling of the states at its final position with considerable improvement in speed of response.
55 citations
TL;DR: In this paper, a flight envelope protection system for NASA's Transport Class Model is presented, based on a command-limiting architecture that accounts for aircraft adverse aerodynamics, unusual attitude, and structural integrity and is designed to augment a standard gain-scheduled flight control law.
Abstract: This paper presents a flight envelope protection system for NASA’s Transport Class Model. The developed protection scheme is based on a command-limiting architecture that accounts for aircraft adverse aerodynamics, unusual attitude, and structural integrity and is designed to augment a standard gain-scheduled flight control law. The scheme also includes an energy protection system, which relies on an automatic throttle control loop that implements a total energy control law. In the setup adopted, the limits of the protected envelopes are actively adjusted to ensure, on the one hand, that the aircraft always stays in a safe flight condition and, on the other hand, that the pilot has enough control authority to perform aggressive maneuvers, if needed. Batch simulations demonstrate the efficacy of the protection system in maintaining the aircraft within desired safe conditions.
34 citations