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Width-pulse control of a flexible satellite at damping and guidance on the Sun and on the Earth

After a spacecraft branching from a launcher the spacecraft (SC) attitude control system begin to work at a damping mode for decreasing the satellite angular momentum vector. For this objective the angular rate sensor block and the orientation engine unit are applied. After the SC damping with needed accuracy there are carried out the Sun initial guidance mode and the Earth initial guidance mode which is completed with a momentum of a rotor by the gyromoment stabilizer. The direction models on the Sun and on the Earth for any SC position at elliptic orbit, models of attitude motion for spacecraft with a flexible structure and models of needed components by the attitude control system, are presented. These components include the jet engines with width-pulse modulation of the thrust control and a physical time delay. There are described elaborated algorithms for the Sun and the Earth search, algorithms for multiply discrete filtering the accessible discrete measures which are carried out also with a time delay.
The solved problem of structure-parametric synthesis by discrete algorithms for the onboard processing information and for the jet engines’ control have the peculiarity: a essential influence of the solar array panels’ flexibility at weak own damping – the oscillation decrement for each tone. The discrete control algorithms’ structure is picked out at modeling motion of the SC at a rigid body.
At example of the communication satellite Sesat there was carried out the stability analysis of processes by the SC control at the initial modes. Parametric synthesis of the discrete algorithms for multiply filtering and for the width-pulse control was elaborated for simplified models of the SC motion on the channels on the base linearization, spectral and frequency methods, and also the Lyapunov function method. Complete parametric synthesis of the discrete control algorithms for full spatial model of the flexible spacecraft motion at its guidance on the Sun and on the Earth with a starting the gyromoment stabilizer rotor was carried out by computer imitation.
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