Development of a Microgravity Uas Test Bed

Abstract

The ultimate goal is to develop a vehicle that can produce a microgravity environment for space system research within a small to medium sized UAV. This weight class of vehicle provides a platform that is more available and less expensive than other methods of generating microgravity which ultimately makes it a better choice for underfunded researchers. It is possible to achieve weightlessness with manual flight but due to the nature of smaller aircraft, pilot input must be more responsive to counteract the larger effects of atmospheric conditions on the airframe. Alternatively, an on board computer can control the vehicle with enough responsiveness to mitigate these effects. The first step in creating an autonomous microgravity UAS is the development of the flight control logic. Multiple concepts for controlling the vehicle are discussed and ultimately a flight path and throttle controller are selected. Aerodynamic models were developed and validated in digital Datcom and X-Plane so that simulation results were more realistic. A Simple 3 DOF simulator was created to show that the proposed controller can generate a microgravity environment with high repeatability. The next step is to then integrate the flight model and controller into a higher fidelity 6DOF X-Plane simulation. Here, HIL tests can be conducted using X-Plane software which shows the ability of the system to create microgravity. A HIL test plan has been developed to determine the systems ability to respond to to simulated gust effects. The microgravity system is ultimately judged on duration and quality of the weightlessness during HIL. Finally, the flight computer was integrated into a COTS vehicle and a flight test plan was developed.