Development of a Fault tolerant control and supervisory system for a NanoSat
Nanosats are miniaturized satellites whose size is around 25cm long and lightweight (1 to 10kg). Such kind of satellites are becoming popular and they are used for a large number of military, civilian and scientific purposes. Nanosats are designed for very specific purposes: atmospheric studies, weather issues, satellite observations, new technology test-bed, among others. Thereby, Nanosats are conformed by a communication device and few instruments. Moreover, due to its small size and weight they can piggyback onto other space missions. Consequently, the construction and put in orbit costs are considerably cheap.
The satellites are usually semi-independent computer controlled systems. Usually an onboard computer attends several tasks: orbit control, attitude control, thermal control, power generation, etc. whereas some other tasks require the intervention of ground control on Earth through telemetry information. Moreover, hardware redundancy is incorporated diminishing in this way the risk of a loss of the mission. Nevertheless, Nanosats are becoming popular in interplanetary missions where communications with the Earth can take several minutes (or even more) and it is too long to receive important instructions such as adjustments in solar panel misalignments, fault diagnosis and corrections, etc. Besides, due to size constraints, hardware redundancy is not affordable. One solution to such kind of problems, is to equip Nanosats with autonomous capabilities for maneuvering as well as with fault diagnosis and correction capacities.
Autonomous guidance and navigation and fault detection and reconstruction algorithms have been studied for diverse space missions, see the references. Such techniques seem to potentially improve the autonomy of the space systems, but there exists a lake of clear guidelines to design a FDIR/FTC (Fault Detection Isolation Recovery/Fault Tolerant Control) solution. Furthermore, the way to manage the interaction between the FDI and FTC units has not been studied in the academic literature. Especially, the problem of guaranteeing stability and performance of the overall fault tolerant scheme taking into account every parts and sub-parts of the FTC strategy as well as the re-configuration mechanism. The stability of the whole system, is often disregarded, even when it is an important aspect outlined by many authors. From a practical point of view, this shortcoming is addressed through a Monte-Carlo campaign. As a direct consequence, even if the stability can be ensured, there does not exist any proof of global optimality of the FTC scheme since the controllers and the FDI/fault estimation algorithms are designed separately.
These drawbacks will be addressed during the thesis. The goal is the design of an autonomous fault tolerant control and supervisory system for Nanosats. The system should have decision capabilities in the context of the interplanetary mission scenarios where most of the decisions should be taken on-line. Moreover, such information may be analyzed off-line for diagnosis to the occurrence of diverse kind of faults (abrupt, incipient, transient, permanent, etc.).
General work planning:
- Revision of the state of art
- Design of robust observers for state estimation in spite of uncertainties considering incomplete and not fully reliable measures (i.e. faults occurrence).
- Detection of faults in order to change the operation mode of the control scheme (active fault tolerant control)
- Fault reconstruction algorithms for on-line compensation and/or posterior off-line analysis and -take off decisions from Earth
- Design of fault detection and fault reconstruction algorithms for actuators and sensors
- Design of fault tolerant control (active/passive schemes)
- Algorithm validation on an industrial simulator at University of Bordeaux
- Writing of scientific articles
Framework
The Master thesis will be cosupervised in collaboration with Dr. Jerome Cieslak and Prof. David Henry that are specialists in model-based FDIR/FTC with many space applications from industries (µScope satellite, Mars Sample Return mission, Myriade satellite, Debris de-orbiting, In Orbit Assembly mission ...) from the IMS Lab (Integration: from materials to systems), University of Bordeaux, Bordeaux, Fr. Prof. David Henry serves as an external expert in GNC (Guidance Navigation Control) for the European Space Agency (ESA).
Candidate profile
- B. Eng. Or B. Sc. Degree in systems and control, electrical, electronic, mechatronic or aerospace, etc.
- Good English level (French is not mandatory).
- Strong analytical and communications skills.
How to apply
Candidates must send a detailed CV and motivation letter to supervisors (dferreira@citedi.mx). The full instructions for the postgraduate call can be checked at
Starting date
Flexible August or February
Workplace / research stays:
CITEDI IPN Tijuana, B.C. (www.citedi.mx), Mx. / IMS Laboratory, University of Bordeaux, Fr. (https://www.ims-bordeaux.fr)
Contact:
Dra. Alejandra Ferreira de Loza (dferreira@citedi.mx) https://www.researchgate.net/profile/Alejandra_Ferreira_de_Loza
References
[1] Zolghadri, A., Henry, D., Cieslak, J, Effimov, D., Goupil, P. (2013) Fault diagnosis and fault tolerant control and guidance for aerospace vehicles: from theory to application. London: Springuer-Verlag.
[2] A. Ferreira de Loza, J. Cieslak, D. Henry, A. Zolghadri, L. Fridman, (2015) Output tracking of systems subjected to peturbations and a class of actuator faults based on HOSM observation and identification, Automatica, 59, 200-205.
[3] H. Wojtkowiak, O. Balagurin, G. Fellinger, H. Kayal, (2013) ASAP: Autonomy through on-board planning, Proceedings of the 6th Conf. on Recent Advance on Space Technologies, pp. 377-382.
[4] Edwards, C., Lombaerts. Smaili, H. (2010) Fault tolerant flight control. Lecture notes in control and information sciences, No. 399 Springuer-Verlag.
[5] J. Cieslak, A. Ferreira de Loza, D. Henry, J. Davila and A. Zolghadri, “Sliding mode observers for multisensors avionics systems”, Euro Guidance Navigation and Control Conference 2015, Apr. 13-15, Toulouse Fr., pp. 323-341
[6] D. Henry, E. Bornschlegl X. Olive and C. Charbonnel. “A model-based solution for fault diagnosis of thruster faults: Application to the rendezvous phase of the Mars Sample Return mission”. Series: “Progress in Flight Dynamics, GNC and Avionics ”. Eds. TORUS, pp 423-442. 2014.
[7] R. Fonod, D. Henry, C. Charbonnel, E. Bornschlegl, D. Losa, S. Bennani. “Robust FDI for fault-tolerant thrust allocation with application to spacecraft rendezvous”. Control Engineering Practice. vol. 42. pp. 12-27. 2015 (10.1016/j.conengprac.2015.05.004),
[8] D. Henry. Fault Diagnosis of the Microscope Satellite Thrusters using Hinf/H- Filters. AIAA Journal of Guidance, Control, and Dynamics. vol 31, n. 3, pp. 699-711, 2008.
[9] C. Pittet, A. Falcoz, D. Henry. “A Model-based diagnosis method for transient and multiple faults of AOCS thrusters”. 20th IFAC Symposium on Automatic Control in Aerospace - ACA 2016. 21-25 August, 2016, Sherbrooke, Quebec, Canada
[10] D. Henry, C. Le Peuvedic, L. Strippoli, F. Ankersen. “Model-based FDIR and fault accommodation for a rendezvous mission around the Mars planet: the Mars Sample Return case”. 4th IFAC International Conference on Intelligent Control and Automation Sciences (ICONS 2016). Reims, France, 1-3 June 2016.