ESA GNC Conference Papers Repository

ESA are currently funding a study aimed at prototyping several AOCS sensor and actuator models to be used for AOCS performance analysis and validation on a range of test environments, including Avionics test benches. The development of such models offers the potential for reductions in effort through the reuse of validated unit models throughout the design, verification and validation lifecycle, and across the European AOCS community. A consortium, led by Tessella, including Thales Alenia Space, EADS Astrium, and unit suppliers, is working together to develop these generic models for specified units, ensuring that development guidelines are specified in order to meet the needs of the AOCS community, and that the models are validated against real hardware. Currently, the project is starting the model development phase. These models will follow the development guidelines to ensure they will be: • Usable on the full range of simulators and benches used in AOCS design, verification and validation, from Matlab/Simulink simulations through to real time test benches. • Applicable across different missions and therefore to different unit manufacturers, but able to be tuned to represent the performance of specific unit examples. • Able to be used across the community of AOCS providers in Europe. The guidelines consider issues such as functional scope and architecture of model development, model fidelity, interfaces, implementation environment and model verification and validation. During the development of the guidelines, in order to capture the views from the wider AOCS community outside of the core team, a round table event was held at ESTEC. Detailed specifications have been prepared for generic models for three unit examples (star tracker, gyro and reaction wheel). The models will then be implemented, verification tested, tuned using data from unit suppliers and then validated as follows: • For representative performance against real hardware for two unit examples. • For operation on real time test bench environments. This paper presents the results of the completed activities and plans for the model development and validation. The resultant validated models will be made available to the AOCS community in Europe and will be a valuable resource in the future in supporting AOCS design and verification & validation activities.