Our vehicle for the Medical Express 2018 competition is called the RhinoHawk EX. It is a hybrid system in many ways, including flight dynamics, power system, materials, hardware, and software. We are building a multi-rotor with a boost motor to allow for precision landing as well as high speed flight. The multiple propellers provide sufficient control, even without any control surfaces like ailerons or elevators, while allowing for power to be distributed from vertical to horizontal flight.
The energy required for 1 hour of high speed flight is very demanding. As the vehicle gets heavier, it requires more batteries, and as more batteries are added, it gets heavier still. this loop causes the total weight to increase dramatically. In order to get the needed power and energy with the minimal weight, we have elected to build a unique hybrid gas/electric power system. The vehicle will have a gasoline engine and a liquid fuel tank. The engine will power a generator to create the electricity needed to spin the motors. A system this small yet powerful does not currently exist in the commercial market, and we are very excited to be creating something new and useful for the rapidly expanding UAV markets around the world.
We are building our system out of carbon fiber to minimize weight and maximize stiffness. Our vehicle will have a lot of vibration so we have chosen to build it as strong as possible using the most advanced material solutions available on the commercial market. We use a combination of tools to make these parts including CNC machines, Thermoformers, Vacuum Infusers, and Filament Winders.
The electronics system is a complex arrangement of commercial hardware running modified open-source software. The small size and great power of modern electronics enables this impressive system at low cost, but a lot of tweaking and tuning is required to bring it all together. The communications system is also a big challenge in this competition. We are using several electronics boards to process images and calculate vehicle position, as well as several radios to ensure a constant communication link.