Speakers

Title: 
Resonance in the flapping wing flight of insects and robots

Abstract: 
A particular frontier for bio-inspired robotics is centimeter scale locomotion, especially flapping flight. Energetic costs to fly at small body sizes are high, dynamic stability is difficult to ensure, and yet thousands of insect species achieve both power and control often with quite different wingbeat frequencies, mass, and wing morphology. In this talk, I will show how nearly all insects operate as resonant “spring-wing” systems to power flight. This reduces the inertial power costs to accelerate their wings on each stroke. But contrary to the prevailing idea that many insects must operate at their resonant frequency, we find that they are in fact supra-resonant, flapping at frequencies often well above what would seem ideal. Supra-resonance is functionally useful because rapid modulation and control of resonating wings is quite difficult. We will then explore how insects have evolved two different strategies for powering this resonant flight system using muscles that either provide periodic oscillatory forcing or use a stretch-responsive activation to set up self-excited limit cycles. While these two strategies have been known for some time, we find that they can be unified in a single dynamic systems framework that shows how major evolutionary transitions reflect transitions in dynamics. We embody this framework in a dynamically scaled robophysical flapper, where kinematics emerge from mechanics and actuation. We find that these two dynamics regimes are separated by a classic entrainment boundary but also bridged by a region of parameter space enabling smooth transitions between the two flight modes. Finally, we realize this biophysical model in the first at-scale flapping robot that can achieve self-excited oscillations and transition between the two flight modes. Limit cycle based flapping flight provides control advantages including automatic frequency and amplitude tuning to loads and intrinsic perturbation handling.

Biography:
Simon Sponberg is the Glen Robinson Professor in Complex Systems in the School of Physics and the School of Biological Sciences at the Georgia Institute of Technology (Georgia Tech). He received his B.A. in physics and biology from Lewis & Clark College and his Ph.D. in Integrative Biology from the University of California, Berkeley. Afterwards, Simon conducted postdoctoral research at the University of Washington before joining the faculty at Georgia Tech. He and his group (the Agile Systems Lab) has been exploring how neurons precisely orchestrate motor activity at the millisecond scale, how the versatility of muscle arises from the physics of billions of organized tiny molecular motors, how agile flight is powered and controlled at the centimeter scale, and how flowers blow in the wind (and what that does to the pollinators around them). He leads a Multidisciplinary University Research Initiative (MURI) bringing together neuroscientists and engineers from five universities to understand how the brains of organisms achieve fast, flexible perception and decision making in complex sensory environments. He has been the recipient of a Young Investigator Award from the International Society for Neuroethology, a Klingenstein-Simons Fellowship in the Neurosciences, and is a Hertz Fellow.