Vol. 41 - Dependable control and measurement systems modeling for unmanned spacecraft

Reliability and processing performance modeling is an important issue for aerospace and space equipment designers. From system level perspective, one has to choose from multitude of possible architectures, redundancy levels, component combinations in a way to meet desired properties and dependability and finally fit within required cost and time budgets. Modeling of such systems is getting harder as its levels of complexity grow together with demand for more functional and flexible, yet more available systems that govern more and more crucial parts of our civilization's infrastructure (aerospace transport systems, telecommunications, exploration probes). In this thesis promising method of modeling complex systems using Petri networks is introduced in context of qualitative and quantitative dependability analysis. This method, although with some limitation and drawbacks offer still convenient visual formal method of describing system behavior on different levels (functional, timing, random events) and offers straight correspondence to underlying mathematical engine, suitable for simulations and engineering support. Proposed modeling methodology being focal point of this thesis is then shown in use, for evaluation of several variants of mission – functionality – technology trade-off. This is common part of every space endeavor and every additional of supporting decision making process is invaluable. Real life example of analysis performed using proposed methodology is shown on case of Coronagraph Control Box equipment designed and built for European Space Agency PROBA3 mission. PROBA3 and accompanying equipment is designed to be technology sandbox allowing some experimental solution to be flown in space and collect operational heritage.