Hoang-Vu Phan1,2 and Hoon Cheol Park1
1Department of Smart Vehicle Engineering, Konkuk University, Seoul, Korea
2Current address: Laboratory of Intelligent Systems, École Polytechnique Fédérale de Lausanne, Lausanne,
Rhinoceros beetle is one of the largest insects that performs many remarkable modes of locomotion such as flying, crawling, and even burrowing their way underground. In addition, their hindwings can be folded and tucked under the elytra for protection when at rest, and unfolded to operate as flat membranes that generate the aerodynamic forces required for flight. The beetle thus is a good reference for developing a similar-scale flapping-wing robot. In this talk, we first introduce the 16 g beetle-inspired, motor-driven, KUBeetle-S robot, which is truly insect-like in terms of tailless and two-winged configuration, attitude control approach, and hovering flight capability. The robot could remain up to 9 minutes in the air, making it the lightest two-winged robot so far that can sustain free controlled flight with all onboard components. We then present a study on how the beetle and robot survive in-flight wing collision. We demonstrated that the folding mechanism in the beetle’s hindwing serves a crucial shock-absorbing function during in-flight collisions by collapsing and redeploying rapidly (< 5 ms) within a single stroke. We then built a beetle-inspired collapsible wing that can be passively folded and rapidly unfolded (< 7 ms). Implementing the wing on a flapping-wing robot, we showed that the folding mechanism enables the robot to fly safely after collisions. Otherwise, in absence of the folding mechanism, the robot tumbles. This initial result promises to develop a collision-tolerant robot for applications in confined space and cluttered environments.