Development and validation of an “in-the-loop” simulator for small satellites

This thesis represents the synthesis of almost two years of work within the CubeSat team at the Polytechnic University of Turin, and its scope is to illustrate the development of a user-friendly, multi-functional simulator for small satellites. This simulator, called by the proprietary name of StarSim v2.0, will have to perform at least three different kinds of in-the-loop simulation: Algorithm-in-the-loop, Software-in-the-loop and Hardware-in-the-loop, and each of these has to be consistent with the previous ones. In the first chapter, a general introduction to System Engineering is provided, completed with the necessary knowledge to Model-Based Design and Validation techniques, upon which all the rest of this work is based. Chapter 2 shows in details the completed product, completed with User experience description, basic source code explanation and graphic diagrams to explain the general architecture of the Software for the three different operative modes. In Chapter 3 the standard library is detailed: this library of algorithmical models has been developed in parallel to StarSim and provides all the basic models to perform a standard simulation, such as the orbit propagator, the sun vector computer, the solar panel, the battery models and so on. Chapter 4 is devoted to the case study, a comprehensive dynamic modeling and simulation of the electric power system of an orbiting CubeSat, from the algorithms to the actual hardware, which fulfills the aim of validating all the previous work.