US 7,464,899 B2Granted

Method and system for determining a singularity free momentum path

AssigneeHoneywell International Inc.

InventorsMichael R. Elgersma, Daniel P. Johnson, Gunter Stein, Blaise G. Morton, Dennice F. Gayme, Mason A. Peck

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Abstract

A method for avoiding singularities in the movement of CMGs in an array of CMGs in a spacecraft includes a first step where a maneuver command to rotate a spacecraft orientation is received. Then, the torque needed to rotate the spacecraft's orientation is determined. Then, the torque is integrated to determine a momentum path. The momentum path is decomposed into a sequence of straight line segments. For each line segment, a unit vector along the straight line segments is determined. Then, it is determined if there is a continuous path connecting a start point and an end point of the line segment in a plane perpendicular to the unit vector. For each point along the path in the plane perpendicular to the unit vector, a set of gimbal angles is determined.

Claims9

Dependent claims

A method for avoiding singularities in the movement of CMGs in an array of CMGs in a spacecraft comprising:

receiving a command to adjust an orientation of the spacecraft the spacecraft orientation;
computing a torque needed to satisfy the command;
integrating the torque to determine a momentum path;
approximating the momentum path with a plurality of straight line segments;
for each line segment of the plurality of line segments:
determining a unit vector along the straight line segments;
determining if there is a continuous path connecting a starting point and an ending point of the line segment in a plane perpendicular to the unit vector;
determining a set of momentum vectors;
and
calculating a required gimbal movement for the CMGs in the array of CMGs for the set of momentum vectors determined for each of the line segment.

7 more elements

Dependencies are inferred from the claim text.