Planar Aerial Reorientation of an Insect Scale Robot Using Piezo-Actuated Tail Like Appendage

Abstract

Robots today, though capable of performing a growing number of increasingly complex tasks, lack the agility that would be required to perform in a rapidly changing or dynamic environment, especially when compared to animals and insects, they are very rigid in performance. Recent developments in the field of insect-scale flapping wing micro-robots include controlled hovering flight, sensor integration and controlled landing. However, their ability to perform rapid, dynamic motions has not been explored in depth. We present the design, fabrication, and actuation of a insect-sized (142~mg) aerial robot that is equipped with a bio-inspired tail. Incorporating a tail allows the robot to perform rapid inertial reorientation as well as to shift weight to actuate torques on its body. Here we present the first analysis of tail actuation using a piezo actuator, departing from previous work to date that has focused exclusively on actuation by DC motor. The primary difference is that unlike a geared motor system, the piezoelectric-tail system operates as a resonant system, exhibiting slowly-decaying oscillations. We present a dynamic model of piezo-driven inertial reorientation, along with an open-loop feedforward controller that reduces excitation of the resonant mode. Our results indicate that incorporating a tail can allow for more rapid dynamic maneuvers and could stabilize the robot during flight.