Research Summaries

Back Control Moment Gyroscopes Duty Cycle for Analysis for Agile Spacecraft

Fiscal Year 2013
Division Graduate School of Engineering & Applied Science
Department Mechanical & Aerospace Engineering
Investigator(s) Ross, Isaac M.
Sponsor National Reconnaissance Office (DoD)
Summary New discoveries at the Naval Postgraduate School show that complex state-dependent geometry of the torque envelopes for CMG spacecraft can be characterized by using the appropriate set of nonlinear dynamical equations. Modem-day embedded microprocessor systems are quite capable of handling the kinds of equations used to describe the CMG torque envelopes. As such, these discoveries can be embedded in the computing hardware and electronics sub-systems of next generation CMG control systems. Doing so will not only extend the capabilities of future CMG systems but will also provide for new ways of designing and operating CMGs, for example advanced power management and fault tolerant control. We propose to explore the issues surrounding the implementation of these new discoveries from the perspective of CMG hardware design. In particular, operating CMGs in a manner that is different from the status-quo can place hereto unknown mechanical demands on the CMG system. We intend to advance our initial discoveries by studying how CMG duty cycles and other mechanical loading characteristics are influenced under full-envelope torque control. This will be done using a combination of theoretical analysis and experimentation on a laboratory scale CMG system. The results can be used alongside the new nonlinear control theories to enhance system performance by removing the restrictive assumptions associated with the current state of the art. Thus, NRO intelligence collection capacity can potentially be revolutionized by enabling unprecedented access to the full torque capability of the spacecraft ACS.
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Data Publications, theses (not shown) and data repositories will be added to the portal record when information is available in FAIRS and brought back to the portal