Homeostatic Control Systems for Spacecraft Power Supply

Abstract

The article dwells upon a problem of reliability of automatic control systems used in the power supply units of spacecrafts. Preserving the survivability of these systems in the process of long autonomous functioning assumes not only a quantitative reservation of their units but the relevant structural organization of their interaction too. The most perfect prototypes of such organization are the biological systems possessing the attribute of homeostasis, i.e., an ability of adaptation to the changing living conditions. Hence, we discuss here the way of realization of this attribute in a control system of spacecraft power supply based on the principles of modularity, hierarchy and the division of functions that are the elements composing the evolutionary concept of multialternativity. The system itself is a multilevel structure with modular components at each level. Transfer of control functions between different modules and levels of a system is carried out automatically depending on the current value of power consumption, opacity of solar panels and the existence of faulty units in the system. When power sources are not sufficient for full provision of all consumers, the system continues it's functioning with the increased value of regulation error until some critical threshold value is reached and after that the system is triggered to the mode of limited power supply. The problem of stability of such system with a variable structure is solved by way of transfer to an active condition of that part of the whole system which is sufficient for active regulation of power output. The identity of modules provides the invariance of dynamic properties of a system in the whole range of a workload. Moreover, the formation of unblocked sub-ranges or zones of active regulation for each module prevents possible avalanche failures in the system.