AirSTAR: A UAV Platform for Flight Dynamics and Control System Testing

Abstract

As part of the NASA Aviation Safety Program at Langley Research Center, a dynamically scaled unmanned aerial vehicle (UAV) and associated ground based control system are being developed to investigate dynamics modeling and control of large transport vehicles in upset conditions. The UAV is a 5.5% (seven foot wingspan), twin turbine, generic transport aircraft with a sophisticated instrumentation and telemetry package. A ground based, real-time control system is located inside an operations vehicle for the research pilot and associated support personnel. The telemetry system supports over 70 channels of data plus video for the downlink and 30 channels for the control uplink. Data rates are in excess of 200 Hz. Dynamic scaling of the UAV, which includes dimensional, weight, inertial, actuation, and control system scaling, is required so that the sub-scale vehicle will realistically simulate the flight characteristics of the full-scale aircraft. This testbed will be utilized to validate modeling methods, flight dynamics characteristics, and control system designs for large transport aircraft, with the end goal being the development of technologies to reduce the fatal accident rate due to loss-of-control.

Investigation of Optimal Control Allocation for Gust Load Alleviation in Flight Control

“…The internal moment about local beam direction 2, 2 M , is the bending moment used as the measured load at the critical points passed to the control allocator in the simulation. The calculation for the internal moment for the beams is given by  M 2  EI 22 k 22 (16) where E is Young's modulus, 22 I is the second moment of inertia about the local 2 beam axis, and 22 k is the curvature about the local 2 beam axis, which is calculated from the displacement solutions and the beam finite element shape function.…”

“…The simulation uses a dynamically scaled representative transport model that is derived from a model of NASA's AirSTAR testbed. The AirSTAR testbed is being developed as part of NASA's Aviation Safety Program to investigate dynamics modeling and control of large transport vehicles in upset conditions 16 . The AirSTAR unmanned aerial vehicle (UAV) is a 5.5% dynamically scaled aircraft based on wind tunnel and flight test data 17 .…”

Flight Dynamics Modelling and Experimental Validation for Unmanned Aerial Vehicles

“…In most projects where time and budget permit, researchers favour to build their own flight models in Matlab and Simulink, or using other generic computer languages like C++ or C for embedded systems (Rasmussen & Chandler, 2002;Berndt, 2004;Buschmann et al, 2004;Jordan et al 2006) . Apparently building a model from scratch is the best way to have full control over the model, and hence can effectively customize the model to meet their specific applications.…”

Avionics Design for a Sub-Scale Fault- Tolerant Flight Control Test-Bed

“…The first approach is to develop a highly realistic experimental environment in simulating a full-scale aircraft operation. For example, the Airborne Subscale Transport Aircraft Research Test bed (AirSTAR) program at NASA Langley research centre uses dynamically scaled airframe equipped with customized avionics for aviation safety research (Jordan et al, 2006) (Murch, 2008). During the research portion of the flight, the aircraft is controlled by a ground research pilot augmented by control algorithms running at a mobile ground station.…”