Novel Approach to Dynamic Soaring Modeling and Simulation

Kai, Jean-Marie; Hamel, Tarek; Samson, Claude

doi:10.2514/1.g003866

Cited by 5 publications

(2 citation statements)

References 14 publications

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“…Seabirds such as albatrosses or petrels extract energy from the lower level of the atmospheric boundary layer over the ocean by climbing upwind into the increasing wind gradient and diving downwind into the decreasing gradient of the wind [1]. Researchers have been studying dynamic soaring [2][3][4], especially with the use of remotely-piloted gliders [5,6]. The most recent achievement for a high-speed dynamic soaring flight was demonstrated by Sachs et al, who simulated the feasibility of reaching close to 600 mph flight speed without using a motor, with the help of dynamic soaring [7].…”

Section: Introductionmentioning

confidence: 99%

Flight Testing of Dynamic Soaring Part-1 : Leeward Inclined Circle Trajectory

Bronz

Gavrilovic

Drouin

et al. 2021

AIAA Scitech 2021 Forum

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This paper presents flight experiments of dynamic soaring as an inclined circle trajectory on the leeward side of a ridge. Energy extraction through dynamic soaring can improve the range and endurance performance of fixed-wing vehicles on certain missions such as ocean monitoring, or flying over orographic wind sources. Real-life application of autonomous dynamic soaring presents challenges such as poor and limited sensor measurements, limited computation, estimation of the dynamic wind field. In this study, we assessed the feasibility of dynamic soaring in the shear layer with a small autonomous glider and showed the positive power contributing segments which are ascending into the positive wind gradient, and descending into the negative wind gradient. Flight test results revealed that, without any complex trajectories, on average, the glider can extract close to 60% of its required power from dynamic soaring. Additionally, a 6-DOF simulation environment is developed with a realistic aircraft model for the initial simulation of advanced trajectories. The results from the flight tests will serve as a database for the researchers to close the gap between simulations and the real flights to achieve a fully autonomous dynamic soaring.

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Section: Introductionmentioning

confidence: 99%

Flight Testing of Dynamic Soaring Part-1 : Leeward Inclined Circle Trajectory

Bronz

Gavrilovic

Drouin

et al. 2021

AIAA Scitech 2021 Forum

View full text Add to dashboard Cite

show abstract

“…A detailed review of relevant phenomena concerning dynamic soaring is presented in Mir et al [17], with a particular attention to applications for autonomous vehicles. Recently Kai et al [18] investigated the effect of dynamic soaring in horizontal wind along an inclined circular path crossing a thin wind shear layer. The flight trajectory is prescribed rather than computed for optimal energy extraction and physical parameters for sustained flight, such as speed increase after a cycle and minimum required wind strength, are discussed.…”

Section: Introductionmentioning

confidence: 99%

On the feasibility of the Rayleigh cycle for dynamic soaring trajectories

et al. 2020

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Dynamic soaring is a flight technique used by albatrosses and other birds to cover large distances without the expenditure of energy, which is extracted from the available wind conditions, as brightly perceived five centuries ago by Leonardo da Vinci. Closed dynamic soaring trajectories use spatial variations of wind speed to travel, in principle, indefinitely over a prescribed area. The application of the concept of closed dynamic soaring trajectories to aerial vehicles, such as UAVs, may provide a solution to improve the endurance in certain missions. The main limitation of dynamic soaring is its dependence on the wind characteristics. More than one century ago, Lord Rayleigh proposed a very simple model, based on the repeated crossing of a step wind profile, presently known as Rayleigh cycle, that provides a clear explanation of the physical phenomenon. The present paper studies the feasibility of closed, single-loop, energy-neutral trajectories for a broad set of wind and vehicle conditions. Through the use of trajectory optimization methods, it was possible to see how the shape of the wind profile, the initial flight conditions and the vehicle constraints influence the required wind strength to perform dynamic soaring trajectories and consequently their feasibility. It was possible to conclude that there are optimal values for the initial airspeed and initial height of the vehicle, that minimize the required wind strength. In addition, it was seen how the structural and aerodynamic constraints of the vehicle affect dynamic soaring at high and low airspeeds respectively. Finally, some new trajectories that can be performed in conditions of excess wind are proposed. The purpose is to maximize the time spent aloft and the path length while maintaining the concept of single-loop, energy-neutral trajectories, making them especially useful for aerial vehicles surveillance applications.

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Full-Envelope Flight Control for Compound Vertical Takeoff and Landing Aircraft

KAI

2024

Journal of Guidance, Control, and Dynamics

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This paper presents a flight control design for compound vertical takeoff and landing (VTOL) vehicles. With their multitude of degrees of controllability as well as the significant variations in their flight characteristics, VTOL vehicles present challenges when it comes to designing their flight control system, especially for the transition phase where the vehicle transitions between near-hovering and high-speed wing-borne flights. This work extends previous research on the design of unified and generic control laws that can be applied to a broad class of vehicles such as hovering vehicles and fixed-wing aircraft. This paper exploits this unifying property and presents an extension for the case of compound VTOL vehicles. The proposed control approach consists of nonlinear geometric control laws that are continuously applicable over the entire flight envelope, excluding the use of switching policies between different control algorithms. A transition strategy consisting of a sequence of high-level set points is associated with the flight control laws; it is defined with respect to flight envelope limitations and is applied in this work to a commercially available compound unmanned aerial vehicle. The control algorithms are implemented on a Pixhawk controller; they are evaluated via hardware-in-the-loop simulations and finally validated in a flight experiment.

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Novel Approach to Dynamic Soaring Modeling and Simulation

Cited by 5 publications

References 14 publications

Flight Testing of Dynamic Soaring Part-1 : Leeward Inclined Circle Trajectory

Flight Testing of Dynamic Soaring Part-1 : Leeward Inclined Circle Trajectory

On the feasibility of the Rayleigh cycle for dynamic soaring trajectories

Full-Envelope Flight Control for Compound Vertical Takeoff and Landing Aircraft

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