Hebrew University of Jerusalem, Israel
Date(s) : 23/03/2022 iCal
14 h 00 min - 15 h 00 min
Insect flapping-wing flight, alongside many other biological and biomimetic modes of locomotion, has a vibrational character: it is founded on patterns of periodic motion, in stark contrast to the non-periodic patterns utilised by artificial locomotive structures (e.g., propellors). As we try to analyse and understand this vibrational character, the phenomenon of resonance hovers uneasily in the background. Resonance offers the prospect of significant energy savings, and performance improvements, based on close tuning between frequency, elasticity, mass, and other structural properties; but details are cloudy, especially when exploring the complex nonlinearities present in real locomotive structures. In this talk, I will discuss how new theoretical results in nonlinear dynamics paint a new picture of the role of resonance in these vibrational modes of locomotion, with a particular focus on insect flight and flapping-wing micro-air-vehicles (FW-MAVs). These results challenge several core assumptions about how resonant systems behave. I will demonstrate i) how even simple vibrational locomotive systems have multiple different resonant states, motivating new approaches to the analysis of insect thoracic resonant properties; ii) how it is possible to access resonant states using only unidirectional actuation, motivating new designs of FW-MAV; and iii) how it is possible to deviate from the resonant frequency and still maintain resonant energetic optimality, motivating new interpretations for insect flight control behaviour. Together, these results provide new insight into the fundamental relationship between nonlinear resonance, elasticity, and energy in insects and FW-MAVs, and provide new qualitative and quantitative tools for the design and analysis of other forms of vibrational locomotive system.