Maximum Torque and Momentum Envelopes for Reaction Wheel Arrays

摘要

Spacecraft reaction-wheel maneuvers are limited by the maximum torque and/or angular momentum that thenwheels can provide. The torque or momentum envelope for an n-wheel configuration can be obtained by projectingnthe n-dimensional hypercube, representing the domain boundary of individual wheel torques or momenta, intonthree-dimensional space via the 3 u0001 n matrix of wheel axes. This paper elucidates the properties of the projectednhypercube and presents algorithms for determining this maximal torque or momentum envelope for general wheelnconfigurations and for distributing a prescribed torque or momentum among the n wheels. We show that thesenalgorithms provide 22, 27, and 33% more capability than the more conventional pseudoinverse algorithm fornconfigurations of four, five, and sixwheels, respectively. Analysis of a representative slew using six wheels shows thatnthese algorithms can provide either a 25%reduction inmaximumwheelmomentumor a 30%reduction in slewtimenwhen compared with the pseudoinverse algorithm.