Longitudinal aerodynamics from a large scale parafoil test program

Iacomini, Christie; Cerimele, Christopher J.

doi:10.2514/6.1999-1732

Cited by 26 publications

(23 citation statements)

References 2 publications

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“…Iacomini and Cerimele have observed, although attributed to brake re ex, the phenomenon of a control reversal for small brake de ections in NASA's X-38 program. 10 In fact, parafoils mostly operate in a skid steering mode when the brake de ections are large. It should be clear from the trends in Figs.…”

Section: Resultsmentioning

confidence: 99%

Aspects of Control for a Parafoil and Payload System

Slegers

Costello

2003

Journal of Guidance, Control, and Dynamics

111

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A parafoil controlled by parafoil brake de ection offers a lightweight and space-ef cient control mechanism for autonomous placement of air-dropped payloads to speci ed ground coordinates. The work reported here investigates control issues for a parafoil and payload system with left and right parafoil brakes used as the control mechanism.It is shown that parafoiland payloadsystems can exhibit two basic modes of lateral control, namely,roll and skid steering. These two modes of lateral steering generate lateral response in opposite directions. For example, a roll steer con guration turns left when the right parafoil brake is activated, whereas a skid steer con guration turns right under the same control input. In transition between roll and skid lateral steering, the lateral response is zero, and the system becomes uncontrollable. Angle of incidence, canopy curvature of the parafoil, and magnitude of brake de ections are important design parameters for a controllable parafoil and payload system and greatly effect control response, including whether the basic lateral control mode is roll or skid steering. It is shown how the steering mode switches when fundamental design parameters are altered and as the magnitude of the brake de ection increases. The mode of directional control transitions toward roll steering as the canopy curvature decreases or the angle of incidence becomes more negative. The mode of directional control transitions away from the roll steering mode as the magnitude of the brake de ection increases, and for "large" brake de ections most parafoils will always skid steer. ; C m0 ; C n0 = rolling, pitching, and yawing moment coef cients from no brake de ection C l ± ; C m ± ; C n ± = rolling, pitching, and yawing moment coef cients from a brake de ection C x0 ; C y0 ; C z0 = force coef cients from no brake de ection C x± ; C y± ; C z± = force coef cients from a brake de ection F

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Section: Resultsmentioning

confidence: 99%

Aspects of Control for a Parafoil and Payload System

Slegers

Costello

2003

Journal of Guidance, Control, and Dynamics

111

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“…Forces and moments from apparent mass and inertia are found by relating the fluid's momentum to its kinetic energy in a similar way as Lissman and Brown [16], and are summarized in Eqs. (13)(14)(15)(16)(17). In the apparent mass contributions, it is assumed that the incidence angle is slowly varying so that its derivative is negligible compared with the body angular rates.…”

Section: Parafoil Dynamic Modelmentioning

confidence: 99%

“…A detailed description of the basic mechanical design of the glide slope control mechanism is provided next. Traditional parafoil dynamic models treat the canopy orientation fixed with respect to the payload [11][12][13][14]. These traditional models allow effects such as apparent mass to be easily incorporated.…”

mentioning

confidence: 99%

Use of Variable Incidence Angle for Glide Slope Control of Autonomous Parafoils

Slegers

Beyer

Costello

2008

Journal of Guidance, Control, and Dynamics

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“…Analysis of previous work [11][12][13]15,[19][20][21][22] that addresses model verification leads to the conclusion that major differences between them lie in the way authors account for the influence of numerous interrelated parameters on the motion of entire system. This paper does not intend to discuss various numerical techniques of parameter identification (PID), 23 but briefly mentions the physical issues (multicriteria essence) behind the identification process.…”

Section: Introductionmentioning

confidence: 99%

On the Development of a Six-Degree-of-Freedom Model of a Low-Aspect-Ratio Parafoil Delivery System

Mortaloni

Yakimenko

Dobrokhodov

et al. 2003

17th AIAA Aerodynamic Decelerator Systems Technology Conference and Seminar

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Numerous papers in the area of parafoil system design have been published over the past 50 years. They cover the following major topics: The future of the Army's air delivery mission includes the use of precision-guided autonomous airdrop methods to resupply troops in the field. High-glide systems, ram-air parafoil-based, allow for a safe standoff delivery as well as wind penetration. This paper addresses the development of a six-degree-offreedom model of a low-aspect ratio controllable parafoil-based delivery system. The model is equally suitable for modeling and simulation and for the design of guidance, navigation and control (GNC) algorithms. This gliding parafoil model was developed in the MATLAB/Simulink ® environment. Apparent mass and inertia effects are included in the model. Initial test cases have been run to check model fidelity.Advanced computational methods for the 3D flow simulation around the parafoil canopy; [1][2][3] Wind-tunnel experiments; [4][5][6][7] Real drop experiments. [8][9][10][11][12][13][14][15][16][17][18]

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Longitudinal aerodynamics from a large scale parafoil test program

Cited by 26 publications

References 2 publications

Aspects of Control for a Parafoil and Payload System

Aspects of Control for a Parafoil and Payload System

Use of Variable Incidence Angle for Glide Slope Control of Autonomous Parafoils

On the Development of a Six-Degree-of-Freedom Model of a Low-Aspect-Ratio Parafoil Delivery System

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