Explicit laws for tuning power gyroscopic complexes of multiple circuits in problems of controlling the orientation of a spacecraft

1Yefymenko, MV
1«Hartron-UKOM» scientific manufacturing company, Limited Liability Company, Zaporizhia, Ukraine
Space Sci. & Technol. 2019, 25 ;(1):27-37
Publication Language: Russian
Currently, the most effective way to obtain data on the Earth's surface is satellite imagery. To obtain high-quality images of the earth's surface, the satellite must be oriented in space with very high accuracy. The required orientation accuracy is 2–5 angular minutes, and the error of stabilization in angular velocity, depending on the spatial resolution, should be no worse than 10–3 … 10–4 degrees per second. In addition, such devices are subject to high demands on the dynamic characteristics of spatial turns during shooting. The turn must be carried out from any current to any given position. The angular velocity during the rotation can reach a value of 2¾3 degrees per second. Power gyroscopic complexes (PGC) are usually used as the actuators to ensure such high dynamic characteristics of satellites in their orientation systems. PGC is a redundant system (more than 3) of two-degree power gyroscopes (gyrodynes).
      The article deals with the problem of spatial reorientation of a spacecraft using a PGC.  A control algorithm for the PGC is proposed, which ensures a given orientation of the spacecraft and the optimal configuration of gyrodynes. The proposed algorithm is based on explicit laws for tuning gyroscopic complexes, which are nonlinear algebraic equations relative to tuning options. In contrast to the well-known works, it is proved that the nonlinear algebraic equations underlying the explicit laws of the setting are compressive mappings. Thereby, the simple iteration method can be applied to find the settings from these equations. Computationally, the method is very simple and can be used in onboard algorithms. The results of numerical modeling of the proposed algorithm are given.
Keywords: attitude control, gyrodyne, spacecraft