| 摘要 |
PURPOSE: To automatically restore the lost earth direction of the yaw-directional axis of the satellite by making it possible to resupply the energy of a flywheel and an earth sensor, measure the rotational frequency or angular speed of the flywheel, and measure or predict each angular momentum of the satellite when the pitch directional attitude passes a zero point. CONSTITUTION: A new angular speedωc which decreases or increases the rotational frequency of the flywheel 7 alternately is commanded each time the pitch-directional attitude detected by the earth sensor passes another zero point (θ=0). In this case, the variation in the commanded angular speed is qHs /Iw (Hs is the angular momentum of the satellite 2, Iw is the moment of inertia of the flywheel 7, and the coefficient (q) is represented as 1<q<2). Lastly, this is repeated until the angular momentum of the satellite 2 decreases below a previously given value Hso when a zero point is passed. Consequently, the satellite can speedily and automatically be re-set to its correct pitch-directional attitude at low cost.
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