FDIR Approach of a Modular Satellite Platform Architecture

摘要

In recent years, constellations of small satellites have been proposed for a wide variety of applications. Given the number of satellites in such constellations, there is a growing need for autonomy of the single satellite to reduce the required ground operations. Here, fault detection, isolation and recovery (FDIR) mechanisms are crucial to ensure maximum operation time with minimal interference from ground. Technische Universitat Berlin developed TUBiX20, a modular nanosatellite platform to support future missions of the university. The TUBiX20 platform implements a hierarchical FDIR concept corresponding with the breakdown of its architecture into four levels: components, devices/nodes, subsystem, and system. Furthermore, the distinction between service layer and user layer enables extensive reuse and results in a clear code structure. The classification of faults regarding the FDIR level is based on which level recovery is performed, not where the fault occurs. This paper gives an overview of the TUBiX20 FDIR implementation on all levels. After introducing relevant aspects of the TUBiX20 platform architecture, the hierarchical FDIR concept is described. Here, the attitude control system as well as the electrical power system are used as examples to illustrate the subsystem level FDIR implementation. The paper concludes with a description of a test framework, which supports the entire development cycle, from testing single PCBs to on-orbit system diagnosis within the FDIR system.