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On-Board System Identification for Uncertainty Modelling and Characterization.

Programme Reference
Prime Contractor
National Technical University of Athens (NTUA)
Start Date
End Date
On-Board System Identification for Uncertainty Modelling and Characterization.

The objective of this activity is to release such accurate and expensive modelling and characterisation task by the on board implementation of adaptive controllers with on-line model determination function to cope with or remove system uncertainties. The feasibility, performance and system level impact of this function need to be evaluated. The applicability for Guidance Navigation and Control systems performing a Rendez Vous on elliptical orbits with unprecise ephemerids will also be analysed.


Future spacecraft missions require high accuracy (in relative and absolute kinematics as well as attitude parameters). Accurate pre-flight knowledge of the plant to be controlled is today necessary for designing accurate Attitude and Orbit Control Systems (AOCS) or instrument pointing systems (including for instance precise structural modal analysis).The on-board modelling techniques addressed in this study shall be categorized as model based estimation and identification techniques for the online dynamic (attitude control) and kinematic (relative orbit for RV) model generation and model calibration. On-line model acquisition techniques shall be developed with the purpose to identify accurately, in a computational efficient and reliable manner the right model parameters that support the AOCS or GNC systems needs. The algorithms to be developed shall rely on on-line filtering, on-line estimation (uncertainty and disturbance observers) and on-line system identification techniques (parametric and non parametric techniques). These techniques are all designed to generate corrective model data and corrections to perturbation signals which cannot be or would not need anymore to be reliably predicted on ground. The validation and verification issues associated with the development of the on-line modeling strategies shall be included in the study.The activity shall include the following tasks:1) Review and select candidates which would benefit from on-board uncertainty modelling techniques 2) Assess the dynamic and kinematic modelling requirements for a high performance mission 3) Perform a trade-off study between the various on-line model identification techniques and perform a final selection of candidate techniques 4) Develop a SW prototype and integrate it in a GNC system functional simulator 5) Evaluate performance and system impact and issue recommendations

Application Domain
Generic Technologies
Technology Domain
5 - Space System Control
8 - System Design & Verification
Competence Domain
3-Avionic Systems
5-Space System Control
Initial TRL
Target TRL
Public Document
Executive Summary
Final Presentation