b. Bio-inspired Ornithopter

Principal Investigator: Jae-Hung Han
Participating Researcher: Addo-Akoto Reynolds
Related Projects: NRF-UVARC(한국연구재단-무인이동체원천기술개발사업단)

Bioinspired ornithopter research group in the SSHS Lab. ultimately pursues the development of agile, stable, and autonomous ornithopter platforms, motivated from the flight mechanism/control strategy of biological flyers. We are seeking efficient methodologies for modeling structural, aerodynamic, and flight dynamic characteristics of ornithopters through investigating semi-empirical flapping-wing aerodynamic model, modal-based flexible multi-body dynamics, and system identification strategy using Magnetic Suspension and Balance System (MSBS). For more detailed research activities, refer to the contents below or our multimedia channel.

Related Recent Publication:

Han, J.-S. and Han, J.-H., “A contralateral wing stabilizes a hovering hawkmoth under a lateral gust,” Scientific Reports, Vol. 9, pp. 393-406, Oct. 2019.
Addo-Akoto, R., Han, J.-S. and Han, J.-H., “Infuence of aspect ratio on wing–wake interaction for fapping wing in hover,” Experiments in Fluids, Vol. 60, No.11, Article ID 164, Oct. 2019.
Han, J.-S.,Nguyen, A. T. and Han, J.-H., “Aerodynamic characteristics of flapping wings under steady lateral inflow,” Journal of Fluid Mechanics, Vol. 870, pp. 735-759, Jul. 2019.
Han, J.-S., Kim, H.-Y. and Han, J.-H., “Interactions of the wakes of two flapping wings in hover,” Physics of Fluids, Vol. 30, Issue 2, Article ID 021901, Feb. 2019.
Addo-Akoto, R. and Han, J.-H., “Bidirectional actuation of buckled bistable beam using twisted string actuator,” Journal of Intelligent Material Systems and Structures, Vol. 30, No. 4, pp. 506-516, Mar. 2019.
Kim, H.-Y., Han, J.-S. and Han, J.-H., “Aerodynamic effects of deviating motion of flapping wings in hovering flight,” Bioinspiration & Biomimetics, Vol. 14, No. 2, Article ID 026006, Feb. 2019.
Han, J.-S., Chang, J. W., and Han, J.-H., “An aerodynamic model for insect flapping wings in forward flight,” Bioinspiration & Biomimetics, Vol. 12, No. 3, Article ID 036004, Jun. 2017.
Han, J.-S., Chang, J.-W., Han. J.-H., “The advance ratio effect on the lift augmentations of an insect-like flapping wing in forward flight,” Journal of Fluid Mechanics, Vol. 808, No.12, pp. 485-510 Dec. 2016.
Han, J.-S., Kim, J.-K., Chang, J.-W., Han, J.-H., “An improved quasi-steady aerodynamic model for insect wings that considers movement of the center of pressure”, Bioinspiration & Biomimetics, Vol. 10, pp.14, Jul. 2015.
Han, J.-S., Chang, J.-W., Kim, J.-K.,Han, J.-H., “Role of Trailing Edge Vortices on the Hawkmoth-like Flapping Wing”, Journal of Aircraft, Vol. 52, pp.1256-1266, Jul. 2015.

1. Goal

– Develop efficient computational methods to simulate the unsteady aerodynamics of insect flapping wings.

– Study the characteristics of dynamic flight stability of insect-like flapping-wing MAVs.

2. Approaches

– Computational models based on the potential flow theory for the unsteady aerodynamics of insect flapping wings

– Multi-flexible body dynamics simulation

3. Past Achievements

▶ SF-3 design and development

– Computer-based design approach for the SF-3 development

SSHS Lab ornithopter, SF-3 simulation model and HW prototype

SSHS Lab ornithopter SF-3 HSC recording for pitch attitude tracking experiment

▶ Wing beat frequency-dependent multiple trim conditions of the ornithopters

– Inherently oscillatory flight states at trimmed flights due to the flapping motion
– Multiple trim conditions with respect to the wing beat frequency (characterized as a stable limit-cycle oscillation)
– Stable limit-cycle trim trajectories: recovered to trim condition after the disturbance

▶ Pitch attitude stabilization for the ornithopter flight

– Ornithopters suffer from constantly oscillating flight dynamic characteristics due to their inherent flapping propulsion mechanisms, and it degrades the quality of obtained image/video
– Bioinspired preshaped tail wing motion (harmonic & phasically synchronized w/ main wing motion)
– Prediction-Error Method (PEM) for the system identification
– LQG regulator design for pitch stabilization, and comparison with Bioinspired preshaped motion

▶ Flow Visualization and Aerodynamic Characteristics of an Insect-like Flapping

Hovering Flight with PIV Analysis


Forward Flight Test using Flapping Robot

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