Generalized math model for simulation of high-altitude balloon systems

Modeling and stability of balloon-borne gondolas with coupled pendulum-torsion dynamics

“…Table 1 presents the frequencies of the eigenmodes predicted by the proposed model, i.e. the solutions in ω of the characteristic equation det(Mω 2 − K) = 0 where M and K are defined by equations (18) and (19), respectively.…”

“…The pendulum modes 3 and 4 represented a large contribution to the telescope's pointing error during the FIREBall 2018 flight [3]. Modes 3 and 4 can be excited by wind gusts [18], but also by the azimuth control of the gondola because of the inertia coupling. Pendulum modes of higher frequency (5 and more) are essentially oscillations of the elements of the flight train.…”

“…Although the stiffness is generally experimentally determined by system identification, which requires to deploy the whole system and process in-flight data, the bifilar pendulum model allows to analytically derive the stiffness of balloon flight chains [16,17]. About the two other axes, balloon flight trains experience a dynamic behavior typical of a floating multiple pendulum, which can be modeled with Lagrange's mechanics [11,18] or multi-body approaches [19,20]. These dynamics have received less attention in the literature, and even when they are modeled, the azimuth control is most often designed by considering only a model of the torsion of the flight train around the vertical axis.…”

A Raspberry Pi-Based Attitude Sensor

“…zodiacal light or airglow) with wide field of view (FOV) instruments. A key requirement for these observations is accurate and stable pointing in spite of the wind speeds of tens of knots and local turbulence known to exist at altitudes above 30 km [Chingcuanco, 1989], which cause the payload to sway and rotate [Hazen, 1985;Nigro et al, 1985]. We are developing a 3-axis stabilization system to correct for these random motions, where the first step is development of an attitude sensor to determine the pointing direction.…”

Practical analytical model to predict high-altitude balloon shape and film tension

“…With wider applications of high-altitude balloons as a cost-effective means in the Earth's atmosphere, there is growing interest in assessing balloon performance and failure mechanism. 1 Various experimental [2][3][4] and analytical 2,5,6 techniques have been developed to predict geometrical shape and stress state of high-altitude balloon. Most of experimental methods are still largely based on experience and empirical data for balloon analysis.…”