Accession Number : AD1030899


Title :   Experimental Test Rig for Optimal Control of Flexible Space Robotic Arms


Descriptive Note : Technical Report


Corporate Author : Naval Postgraduate School Monterey United States


Personal Author(s) : Griggs,Martin J


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/1030899.pdf


Report Date : 01 Dec 2016


Pagination or Media Count : 141


Abstract : The goal of this thesis was to build an experimental test rig for demonstrations on flexible space systems control. Specifically, an air-bearing test bed incorporated a two-degree of freedom (2DOF) rigid robotic arm and an appendage with flexible joints to test the effects of movement of the robotic arm on the appendage. The two-link, 2DOF rigid robotic arm can be used to simulate a moving space antenna or other movable appendages. Optimal trajectories of the two-link arm to simulate a conventional antenna slewing maneuver were investigated, to illustrate the type of flexible motion that may be produced in the laboratory. An iterative process was used to refine the test bed design and the experimental workflow. Three concepts incorporated various strategies to design a robust flexible link. Inertia measurement units(IMU), a central processor for data analysis, power distribution, and robotics software, are all integrated as part of the test bed design. A single link arm with a torsional, helical spring at the base was finalized to investigate the effects of coupling due to movement of the rigid two-link arm. The torsional spring allowed the vibrating arm to displace sufficiently to have a high signal-to-noise ratio compared to earlier concepts in which IMU noise dominated the response. The test bed was designed to accommodate further testing that may require increased loading due to, for example, the incorporation of reaction wheels or additional instrumentation.


Descriptors :   space systems , computer programming , accuracy , angular acceleration , data processing , equations of motion , gas bearings , spacecraft , trajectories , center of gravity , VIBRATIONAL SPECTRA , robotics , optimization , control , artificial satellites , degree of freedom


Subject Categories : Spacecraft Trajectories and Reentry
      Cybernetics


Distribution Statement : APPROVED FOR PUBLIC RELEASE