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Results for “formation control testbed (FCT)”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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Flight-Like Ground Demonstrations of Precision Maneuvers for Spacecraft Formations

Synchronized formation rotations are a common maneuver for planned precision formations. In such a rotation, attitudes remain synchronized with relative positions, as if the spacecraft were embedded in a virtual rigid body. Further, since synchronized rotations are needed for science data collection, this maneuver requires the highest precision control of formation positions and attitudes. A recently completed, major technology milestone for the Terrestrial Planet Finder Interferometer is the high-fidelity, ground demonstration of precision synchronized formation rotations. These demonstrations were performed in the Formation Control Testbed (FCT), which is a flight-like, multi-robot formation testbed. The FCT is briefly introduced, and then the synchronized rotation demonstration results are presented. An initial error budget consisting of formation simulations is used to show the connection between ground performance and TPF-I flight performance.

formation flying↗

Ground Demonstration of Synchronized Formation Rotations for Precision, Multi-Spacecraft Interferometers

This paper reports the ground demonstration of precision synchronized formation rotations with better than 6 arcmin/5 cm performance in the Formation Control Testbed (FCT). The FCT currently consists of two, five degree-of-freedom, air bearing-levitated robots. The sixth degree-of-freedom, vertical translation, is being added in November 2007. Each robot has a suite of flight-like avionics and actuators, including a star tracker, fiber-optic gyroscopes, reaction wheels, cold-gas thrusters, inter-robot communication, and on-board computers that run the Formation and Attitude Control System software.

ground demonstrations↗

Optical Pointing Sensor

The optical pointing sensor provides a means of directly measuring the relative positions of JPL s Formation Control Testbed (FCT) vehicles without communication. This innovation is a steerable infrared (IR) rangefinder that gives measurements in terms of range and bearing to a passive retroreflector.

Shields, Joel F.↗

Terrestrial Planet Finder Interferometer : TPF-I Technology Milestone #2 Report : formation control performance demonstration

This document reports the achievement of Terrestrial Planet Finder Interferometer (TPF-I) Technology Milestone #2, a ground-based, system-level demonstration of twospacecraft formation synchronized rotation. We review the milestone specification from the Milestone White Paper (May 25, 2007), summarize the experiments performed in the Formation Control Testbed (FCT), detail the procedures and nalysis of the resulting data, and describe and present the data itself.

Lawson, Peter R.↗

Spacecraft inertia estimation via constrained least squares

This paper presents a new formulation for spacecraft inertia estimation from test data. Specifically, the inertia estimation problem is formulated as a constrained least squares minimization problem with explicit bounds on the inertia matrix incorporated as LMIs [linear matrix inequalities). The resulting minimization problem is a semidefinite optimization that can be solved efficiently with guaranteed convergence to the global optimum by readily available algorithms. This method is applied to data collected from a robotic testbed consisting of a freely rotating body. The results show that the constrained least squares approach produces more accurate estimates of the inertia matrix than standard unconstrained least squares estimation methods.

inertia estimation↗

The Formation Control Testbed

This paper describes the design and construction of the Formation Control Testbed. The FCT consists of three robots navigating on an air bearing floor, propelled by cold gas thrusters. Each robot contains an attitude platform supported on a spherical air bearing which provides three rotational degrees of freedom. The sixth degree of freedom, vertical translation, will be provided by a powered vertical stage, actively controlled to provide a simulated zero-g environment for the attitude platform.

Singh, Gurkirpal↗