Development and Initial Testing of the Aero Testbed: A Large-Scale Unmanned Electric Aerobatic Aircraft for Aerodynamics Research

Abstract

This paper describes the development of a large 35%-scale unmanned aerobatic platform named the UIUC Aero Testbed, which is primarily intended to perform aerodynamics research in the full flight regime. The giant-scale aircraft with a 105-in (2.7-m) wingspan and weight of 37 lb (17 kg) was constructed from a commercially available radio control model aircraft with extensive modifications and upgrades including a 12-kW electric motor system that provides a thrust-to-weight ratio in excess of 2-to-1. It is equipped with an avionics suite that contains a high-frequency, high-resolution six degree-of-freedom (6-DOF) inertial measurement unit (IMU) that allows the system to collect aircraft state data. This information set can be used to generate high-fidelity aerodynamic data that can be used to validate high angle-of-attack flight-dynamic models. Collaboration in this project also led the Aero Testbed to have the capability to fly fully-and semi-autonomously in order to conduct autonomous flight research. A literature review of aerobatic unmanned aircraft used for research is first presented. Then the background and motivations for developing this platform are discussed. This is followed by a description of the planning and development that was involved. Finally, initial test flight results are presented, which include flight path trajectory plots of several aerobatic maneuvers. Nomenclature AV I= avionics integration ARF = almost ready to fly COT S = commercial off the shelf CG = center of gravity DOF = degree of freedom EEG = electroencephalogram IMU = inertial measurement unit RC = radio control

Flight Test Protocol for Electric Powered Small Unmanned Aerial Systems

“…The key unknowns in determining the aircraft drag polar are the zero lift drag coefficient, 0 and the span efficiency factor . The standard flight testing method of determining these parameters is to record the aircraft's airspeed over a range of power settings at a constant altitude [1,2,14]. The lift coefficient is estimated from this data assuming a constant aircraft weight, which is uniquely satisfied using an electrical power system.…”

Development and Modeling of a Low-Cost Unmanned Aerial Vehicle Research Platform

“…Developing a UAV research platform to validate these new principles and technologies is of great importance, and so it is no surprise that many UAV testbeds have been developed by various academic groups, e.g., [9,20,25,26,32,36,38,40,42]. The main goal in building our testbed is to develop a lowcost and reliable fixed-wing UAV platform that can be used to implement relatively complex control algorithms.…”

High-Frequency Sensor Data Acquisition System (SDAC) for Flight Control and Aerodynamic Data Collection

“…10,[22][23][24] The RCAT System and Eagle Tree Systems units seem to be the only data recording devices currently available with a small enough form factor to allow them to be installed in a small to mid-sized UAV without being a major hindrance. The specifications for these units are given in Table 3.…”

“…Also, it should be versatile such that it could be used on any platform. The specific sensor handling requirements for the unit were determined by examining previous developed systems 24,31 and by evaluating other existing units, see Section 1.A. The system should yield: 3D linear and angular accelerations, velocities, and position along with GPS location using an IMU; airspeed using a pitot probe and a differential pressure sensor; 3D magnetic field using a magnetometer for heading; control inputs; and control surface deflections using potentiometers.…”