An Overview of the NASA Flying Test Platform Research

Abstract

A methodology for improving attitude stability and control for low-speed and hovering air vehicle is under development. In addition to aerodynamically induced control forces such as vector thrusting, the new approach exploits the use of bias momenta and torque actuators, similar to a class of spacecraft system, for its guidance and control needs. This approach will be validated on a free-flying research platform under development at NASA Langley Research Center. More broadly, this platform also serves as an in-house testbed for research in new technologies aimed at improving guidance and control of a Vertical TakeOff and Landing (VTOL) vehicle. 1 Research Motivation This paper gives an overview of the ongoing research in precision guidance and robust control based on the NASA Flying Test Platform (NFTP) research vehicle currently under development at NASA Langley Research Center. The research is motivated by core GN&C objectives that include optimal guidance and navigation, and robust attitude and position stabilization under uncertain exogenous disturbances and model variations. A key goal of this research is to investigate novel technologies to improve attitude stability particularly during hovering or at low airspeed flight wherein conventional control effectors become ineffective. This particular need arises from current limitations in attitude stabilization performance for

A New Approach to Attitude Stability and Control for Low Airspeed Vehicles

“…This paper outlines recent results in our continuing R&D efforts as first reported in [6]. In the next section, a research vehicle under development at NASA Langley Research Center for maturing this control technology is described, and its equations of motion are given.…”

Hovering Dual-Spin Vehicle Groundwork for Bias Momentum Sizing Validation Experiment

“…These are simplified by fixing the body axes to the vehicle cg. The resulting equations (1,2,3) show coupling between all axes due to both inertial and gyric effects.…”

“…This earlier paper provides expressions for sizing an angular momentum bias given a disturbance environment bandwidth and Power Spectral Density (PSD), and the desired Mean Square Response (MSR) of the vehicle Euler angles and body rates. The hardware, the Dual-Spin Test Device (DSTD) and related support equipment, was in a preliminary state in 2003 and was described in reference [3]. Now the hardware has matured and is ready for both experimental verification of bias momentum sizing expressions and experimental validation of bias momentum sizing methods.…”

Bias Momentum Sizing for Hovering Dual-Spin Platforms

“…A pair of control vanes are attached to the aft of each duct and a momentum wheel is attached to the bottom of the main platform. For more details on the DSTD, see [19], [20], [21]. Table 1 in the system.…”