Power and Actuation Autonomy for Flapping Wing Insect-scale Robots

Abstract

This work aims to advance the field of Flying Insect-scale Robots (FIRs) by presenting solutions for key outstanding problems in wireless power, control, and actuation autonomy. Previous work in was the first ever wireless lift-off of an FIR powered by external laser, and subsequent work has shown an additional wireless power solution using magnetically coupled resonators to be more than adequate for FIRs and also human safe. In ICRA2021 my work proved that the onboard PEU can linearly modulate the thrust required for roll and altitude control, which was an important prerequisite for flight control. Further, the same work also demonstrates that an unaided repetitive control law can learn to regulate output waveforms to reference with zero phase within the span of a few wing strokes, thus providing a valuable feedforward term to waveform generator control in a computationally lightweight form. The primary aim of this body of work is to advance the technology needed for wireless operation of the FIRs. No discrete or off-the-shelf solution yet existed to drive two independent piezoelectric actuators typically selected for FIR flight muscles within the size, weight, and power (SWaP) budget of a robot weighing less than 200 mg. To-date, FIRs have relied on a physical tether to large specialized benchtop systems for power and control signals to the flight muscles and any onboard systems for experiments, thus severely restricting their utility. Power and actuation autonomy represents a key bottleneck in the development of this technology, yet for decades there has been relatively little advancement toward true autonomy. This work presents an exploration of state of the art solutions, and presents new power electronics and waveform generation control to enable such advancement. Specifically, the waveform generation and power electronics work together to result in a doubling of the effective power capacity of our FIRs by improving end-to-end efficiency over the previous state of the art, from 28% to 54% with approximately 75% the weight. This advance in waveform generation and power electronics is the first to demonstrate independent wing control of a comparable FIR by an onboard PEU. This unlocks new frontiers in onboard flight control, sensing, and payload.