Application of Automated Balancing Methods for an Attitude Control Test Platform with Non Orthogonal Masses

Abstract

Ground-based spacecraft simulators provide an accessible and necessary platform for testing and evaluating control systems. The Attitude Control System Proving Ground (ACSPG) at the Air Force Research Laboratory (AFRL) allows for testing and verifying the performance of attitude control systems. Through the use of an air bearing, the frictionless environment is replicated, but gravitational torques are still prevalent. Gravitational torques distort and negatively affect the sustained performance of simulators, limiting experimentation time. Cost effective validation efforts require decreasing current set up times and increasing current experimentation times. The distance between the center of rotation (COR) and the center of mass (COM) of the simulator results in unwanted gravitational torques, causing a tilting and unbalanced platform. Developing an automated system to precisely co-locate the COR and the COM will reduce said torques. This research demonstrates two control techniques to improve the current system balancing procedures. The xC;first method is a non-linear adaptive control and is validated with three primary scenarios, demonstrating an ability to reduce angular velocities to zero. Through tuning, the control algorithm balances the platform according to design constraints. The second method estimates the offset between the COM and COR utilizing a least squares estimation method. The second method is validated with two tests of varying lengths and is able to estimate the offset within 0.5 percent.

Open PDF

Document Details

Document Type
Technical Report
Publication Date
Jun 14, 2018
Accession Number
AD1056661

Entities

People

  • Keith A Hudson

Organizations

  • Air Force Institute of Technology

Tags

Communities of Interest

  • Space

DTIC Thesaurus Topics

  • Air Force
  • Air Force Research Laboratories
  • Algorithms
  • Angular Acceleration
  • Angular Momentum
  • Attitude Control Systems
  • Cartesian Coordinates
  • Control Systems
  • Coordinate Systems
  • Differential Equations
  • Equations
  • Filters
  • Gas Bearings
  • Gravitational Fields
  • Guidance
  • Kalman Filters
  • Military Research
  • Moment Of Inertia
  • Simulations
  • Simulators
  • Spacecraft
  • Steady State
  • United States

Readers

  • Computational Modeling and Simulation
  • Robotics and Automation.
  • Systems Analysis and Design

Technology Areas

  • Space
  • Space - Spacecraft Maneuvers