Gamera-S: Designing and Flying a Manned Solar-Powered Helicopter

Abstract

The University of Maryland's Solar Gamera, or Gamera-S, is a solar-powered quadrotor that has demonstrated piloted flights using only on-board solar panels. Made of carbon fiber and mylar, the structure remains lightweight yet durable, allowing for the achievements in flight accomplished by Gamera-S thus far. There are several solar-powered rotorcrafts that are unpiloted, most significantly being the NASA drone exploring the Martian surface. This creates a question: can we make a viable solar-powered rotorcraft for piloted flight? Gamera-S currently holds the record of 9 seconds in hover at an altitude of 0.1 meters. The team aims for a new flight record of 60 seconds in sustained hover. To achieve this, rotor blade twists are being studied through parametric modeling and finite element analysis to optimize the power efficiency. Scale prototypes of the rotors will also be developed and tested in wind tunnels to validate the optimization outcome. In addition, attitude feedback control methods are being surveyed to improve flight stability and pilot control in the presence of gusts and ground effects. The control law will be verified in SiL simulations prior to being implemented on custom avionics hardware. Furthermore, methods to mitigate power fluctuations and losses, including the addition of bypass diodes and MPPT charging circuits, will be investigated. The effectiveness of such methods will be tested and quantified through solar panel shade testings. Lastly, full-scale flight tests will be conducted to demonstrate that a sustained, or even perpetual, flight through a manned solar-powered helicopter is possible.