This paper addresses the issue of designing a feasible set of trajectories for a stratospheric airship model with the help of bifurcation based direct continuation methodology. An airship envelope is framed based on the maneuverability characteristics of the airship in the steady level circular turn maneuver. From the propounded envelope, appropriate trajectories are defined based on the application to which the airship is deployed. The proposed trajectories are then maneuvered using the nonlinear sliding mode based controller in conjunction with the three dimensional lookahead-based steering guidance law. The pertinent simulation results are presented to prove the efficacy of the designed hover corridor for the airship. © 2018

Nandan Kumar Sinha

Department of Aerospace Engineering

Gobiha D

Maneuverability

Trajectories

Autonomous flight

FEASIBLE SET

Lighter-than-air vehicles

NONLINEAR SLIDING MODE

STATION KEEPING

STEERING GUIDANCE

Stratospheric Airships

Airships

Fulltext

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IFAC-PapersOnLine

This paper proposes the design of simulation framework for a coupled, nonlinear, six degrees of freedom stratospheric airship model by integrating continuation approach with nonlinear sliding mode based control technique. Bifurcation based continuation approach has been engaged to provide an insight on the level skid-to-turn performance which is of significant importance in designing nonlinear control based methodologies for the autonomous maneuvering of airship. Nonlinear sliding mode control framework is implemented in closed-loop for the guidance and control of the proposed airship maneuver. Pertinent simulation results are presented to prove the efficacy of the proposed approach. © 2019, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.

AIAA Scitech 2019 Forum

Nonlinear simulation framework based on bifurcation analysis for controlled airship maneuvering

Hover Corridor for a Stratospheric Airship

Tools based on the bifurcation and continuation method have been found to be extremely useful for studying multiparameter nonlinear dynamical systems under state and parameter-constrained conditions. Because of inherent limitations of the existing methodologies, however, application of continuation techniques to certain types of problems has remained cumbersome and even computationally challenging. This paper provides an alternate direct approach in MATLAB® using its continuation subroutine MATCONT to extend the capabilities of continuation techniques in an attempt to accommodate a wide variety of constrained dynamics problems. Published results in the literature are first reproduced for validation of the proposed approach. A control problem of scheduling gains for the longitudinal flight dynamics of an aircraft is next presented to show usefulness of the proposed methodology, followed by solutions to an aircraft conceptual design problem involving wing morphing with eigenvalue constraints, with the difficulties of the selected problems increasing in that order.

Journal of Aircraft

Direct methodology for constrained system analysis with applications to aircraft dynamics

In this paper, bifurcation analysis of a full six degrees of freedom model of an airship is carried out both in unconstrained and constrained conditions. Equations of motion of airship are first modified to a suitable form and a standard as well as constrained bifurcation analysis performed with respect to airship control and design parameters. Typical modes of airship dynamics and regions of stable flights are identified via this analysis. Loss of stability and mode responsible for onset of instability at critical parameter values are also identified. © 2016 IEEE.

Proceedings of 2016 7th International Conference on Mechanical and Aerospace Engineering, ICMAE 2016

Airship trim and stability analysis using bifurcation techniques

Design of maneuvers for carefree access of an aircraft to its complete flight envelope including poststall regimes is useful not only from a combat strategy point of view, but also for devising recovery strategies from an accident scenario. Maneuvers for an aircraft can be efficiently designed if a priori knowledge of its maneuverability characteristics is available to the control designers. Different types of agility metrics that characterize aircraft maneuvering capabilities have been proposed in literature based on different criteria. The concept is based on the assumption that the boundary of the AER is defined by saturation of one or more control surfaces. Therefore, a point lying on the boundary of AER is initially located using a continuation method. Using the trim point on the boundary as a starting condition, a separate continuation procedure is carried out, with the saturated control fixed at its limit value to obtain the envelope containing attainable equilibrium points.

Journal of Guidance, Control, and Dynamics

Accessible regions for controlled aircraft maneuvering

Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering

Optimum area of solar array for stratospheric solar-powered airship

Journal	Data powered by TypesetIFAC-PapersOnLine
Publisher	Data powered by TypesetElsevier B.V.
ISSN	24058963
Open Access	Yes