Dp 249 en
Failure Detection Expert Software[editovat]
Author: Mulacova Jana
Survival of both, manned and unmanned space missions is a critical and decisive issue. The very expensive costs in research and development, scientific components, and the most important of all, human lives are magnifying the burden on dependability requirements.
The complexity of the avionic systems in spacecrafts is rising as space missions become increasingly more sophisticated. This complexity emphasizes the need for more dependable systems with minimal anomalies. As satellite manufacturers seek to convert many hardwareimplemented functionalities into software, the On-Board Software (OBSW) is becoming a major component in every satellite. Noticeably, more tasks for Fault Detection, Isolation and Recovery (FDIR) are being implemented in software, where the need comes for a welldefined software architecture that supports a cost-effective implementation of the FDIR functions. An effective FDIR implementation is seen as imperative to guarantee a dependable and autonomous system with a minimal risk of ruinous failures. Late definition and incorporation of FDIR technologies in the on-board software life cycle is considered an urgent problem by different satellite manufacturers.
The aim of ground control system developments is a more autonomous system, which can support the operators of a spacecraft in their supervisory and diagnostic tasks and can replace partially the spacecraft controllers in their monitoring tasks. In this case the system shall:
- 1. include prediction functionality, which: monitors mission critical parameters and provides long term trends provides a forecast of these parameters and highlights potential future problems to the spacecraft operations engineer
- 2. include diagnostic functionality, which: provides some initial diagnostic based on considered failures analysis and hints towards the possible contingency procedures for this case.
This could be implemented by extending the functionality of the mission control software or as external application. In order to be mission independent, the envisaged software should be a framework, which needs to be tailored for each mission. In the context of this master thesis the following tasks are foreseen: Analyse the current existing approaches for FDIR and Mission Control Systems Identify and categorise types of failures
Identify and categorise types of failures for an example mission (Venus Express Simulator) Analyse approaches for failure prediction and diagnostic Develop a concept for expert software, which could provide failure prediction and diagnostic functionality Develop a simple prototype of this expert software system to prove the concept The aim of this master thesis is to analyse and develop a concept for an expert software system, which provides diagnostic functionality for existing failures and prediction for likely failures. It should be noted that the aim of the master thesis is not to identify all possible failures for Venus Express Mission, the aim is the concept and the proof of concept.