TY - GEN
T1 - Rotary versus flapping flight
T2 - ASME 2018 Dynamic Systems and Control Conference, DSCC 2018
AU - Ghanaatpishe, Mohammad
AU - Bayiz, Yagiz E.
AU - Cheng, Bo
AU - Fathy, Hosam K.
N1 - Funding Information:
which was initialized using OSS solutions uniformly distributed across the stead-state Pareto front. Figure 6 illustrates the optimization search results after 50 generations of the initial population with blue stars. The corresponding Pareto front is seen to be superior to that of the rotary flight as predicted by the pi test. Figure 7 shows the periodic stroke and pitch angle trajectories for a select optimized solution marked by a blue triangle on the Pareto front of Fig. 6. The small red circles in Fig. 7 represent the optimized values at the discretization points. Finally, Fig. 8 provides a visualization for the optimal flapping and revolving wing flight regimes. Each bar in this figure depicts a side view of the positioning of the wing tip at a given moment in time. The green dots at the top endpoints of these bars denote the leading edge. The time span between the consecutive snapshots of the wing locations is fixed. Therefore, the spacing between the bars is representative of the rate of change of stroke and pitch angles. As seen from Fig.7 and 8, in contrast to the rotary flight, the stroke velocity and the wing’s angle of attack change vary dynamically during the course of each flapping cycle. The wing travels with low angle of attack values and relatively fast speed during mid-stroke to minimize the drag forces. Then, stroke reversal occurs at a rapid pitch rate to decrease the angle of attack for the next half-stroke. 5 Conclusions This paper introduces a framework for analyzing the relative optimality of flapping and revolving wing motions in insect flight models. Due to the small scale of flying insects, viscous effects are substantially amplified, reducing the aerodynamic efficiency of steady-state rotary flight. Flapping flight exploits additional unsteady lift generation mechanisms by dynamically interacting with the surrounding air flow. The flapping flight optimization problem is posed in this work as an OPC problem whose steady-state solution is the best rotary flight configuration. The pi test is then incorporated to assess the impact of periodic perturbations around this optimal steady-state solution. An application of the pi test to a quasi-steady fruit fly model shows that best flapping trajectory always outperforms the optimal revolving wing flight. The manuscript concludes with obtaining the unsteady optimal lift-power Pareto front using a pseudospectral transcription of the optimal flapping flight. The superiority of this Pareto front compared to its steady-state counterpart for rotary flight confirms the predictions of the pi test results. ACKNOWLEDGMENT This research was funded in part by NSF grant #1538300. The authors gratefully acknowledge this support. REFERENCES [1] Ma, K. Y., Chirarattananon, P., Fuller, S. B., and Wood, R. J. “Controlled flight of a biologically inspired, insect-scale robot”. Science, 340. [2] Roll, J. A., Cheng, B., and Deng, X., 2015. “An elec-tromagnetic actuator for high-frequency flapping-wing mi-croair vehicles”. IEEE Transactions on Robotics, 31(2), pp. 400–414. [3] Pines, D. J., and Bohorquez, F., 2006. “Challenges facing future micro-air-vehicle development”. Journal of aircraft, 43(2), pp. 290–305. [4] Ellington, C. P., Van Den Berg, C., Willmott, A. P., and Thomas, A. L., 1996. “Leading-edge vortices in insect flight”. Nature, 384(6610), p. 626. [5] Dickinson, M. H., Lehmann, F.-O., and Sane, S. P., 1999. “Wing rotation and the aerodynamic basis of insect flight”. Science, 284(5422), pp. 1954–1960. [6] Fry, S. N., Sayaman, R., and Dickinson, M. H., 2003. “The aerodynamics of free-flight maneuvers in drosophila”. Sci-ence, 300(5618), pp. 495–498. [7] Sane, S. P., and Dickinson, M. H., 2001. “The control of flight force by a flapping wing: lift and drag production”. Journal of experimental biology, 204(15), pp. 2607–2626. [8] Lentink, D., and Dickinson, M. H., 2009. “Rotational accelerations stabilize leading edge vortices on revolving fly wings”. Journal of the American Helicopter Society, 212(16), pp. 2705–2719. [9] Mayo, D. B., and Leishman, J. G., 2010. “Comparison of the hovering efficiency of rotating wing and flapping wing micro air vehicles”. Journal of Fluid Mechanics, 55(2), pp. 25001–25001. [10] Nabawy, M. R., and Crowther, W. J., 2015. “Aero-optimum hovering kinematics”. Bioinspiration & biomimetics, 10(4), p. 044002.
PY - 2018
Y1 - 2018
N2 - This paper uses optimal periodic control (OPC) theory as a framework for assessing the relative efficiency of revolving versus flapping wing trajectories in insect-sized flight problems. The literature already offers both experimental and simulation-based comparisons between these two flight modes. A collective conclusion from these studies is that the potential advantages of flapping flight depend on many factors such as Reynolds number, wing size/morphology, wing kinematic constraints, aerodynamic efficiency metrics, etc. This makes it necessary to develop a unified framework for comparing these flight modes under various conditions. We address this need by using the π test from OPC theory as a tool for analyzing the degree to which one can improve the efficiency of steady rotary hovering flight through periodic trajectory perturbations. A quasi-steady insect flight model from the literature is adopted as a case study. The paper applies the π test to this model. It then concludes by solving for the optimal lift-power Pareto fronts for both flight modes, and using these Pareto fronts to confirm the results predicted by the π test.
AB - This paper uses optimal periodic control (OPC) theory as a framework for assessing the relative efficiency of revolving versus flapping wing trajectories in insect-sized flight problems. The literature already offers both experimental and simulation-based comparisons between these two flight modes. A collective conclusion from these studies is that the potential advantages of flapping flight depend on many factors such as Reynolds number, wing size/morphology, wing kinematic constraints, aerodynamic efficiency metrics, etc. This makes it necessary to develop a unified framework for comparing these flight modes under various conditions. We address this need by using the π test from OPC theory as a tool for analyzing the degree to which one can improve the efficiency of steady rotary hovering flight through periodic trajectory perturbations. A quasi-steady insect flight model from the literature is adopted as a case study. The paper applies the π test to this model. It then concludes by solving for the optimal lift-power Pareto fronts for both flight modes, and using these Pareto fronts to confirm the results predicted by the π test.
UR - http://www.scopus.com/inward/record.url?scp=85057332460&partnerID=8YFLogxK
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U2 - 10.1115/DSCC2018-9118
DO - 10.1115/DSCC2018-9118
M3 - Conference contribution
AN - SCOPUS:85057332460
T3 - ASME 2018 Dynamic Systems and Control Conference, DSCC 2018
BT - Advances in Control Design Methods; Advances in Nonlinear Control; Advances in Robotics; Assistive and Rehabilitation Robotics; Automotive Dynamics and Emerging Powertrain Technologies; Automotive Systems; Bio Engineering Applications; Bio-Mechatronics and Physical Human Robot Interaction; Biomedical and Neural Systems; Biomedical and Neural Systems Modeling, Diagnostics, and Healthcare
PB - American Society of Mechanical Engineers (ASME)
Y2 - 30 September 2018 through 3 October 2018
ER -