Final Report Summary - ICIEMSET (Innovative Control, Identification and Estimation Methodologies for Sustainable Energy Technologies)
ICIEMSET has been a three-years-long research project involving both theoretical and applied research, carried out at the Department of Mechanical Engineering of the University of California, Santa Barbara (UCSB), for the first two years (outgoing phase) and at the Automatic Control Laboratory of ETH Zürich (ETH) for the third year (return phase). The project started on 1st September 2010 and finished on 31st August 2013. The project’s main field is control engineering, in its broader sense. Controls is the discipline responsible for major accomplishments in diverse modern technological fields, yet new applications pose challenging problems that call for novel fundamental results and further research and development activities. The general aim of ICIEMSET was to devise innovative control design, identification and estimation methodologies and to apply them in advanced energy applications, in particular airborne wind energy. More specifically, the project objectives were:
1. to investigate innovative robust control design techniques that can be employed systematically to address complex problems, characterized by the presence of nonlinearities, constraints and uncertainty;
2. to devise new modelling and identification procedures, that are more appropriate for constrained nonlinear systems and are oriented to robust control design;
3. to study advanced estimation/filtering techniques, able to cope with system nonlinearities and constraints and suitable to be employed for feedback control;
4. to develop techniques and tools for the efficient and practical implementation of the obtained methodologies;
5. to apply the achieved methodological results to the motivating application of wing control for airborne wind energy generation, thus contributing to research and development in the field of sustainable energy technologies.
Along with the technical objectives, another goal of the project was to foster the career development of the involved Marie Curie fellow, through hands-on research, training, dissemination, fund raising and project management activities.
Referring to the mentioned objectives, the following work has been carried out:
1. several control design approaches have been developed to tackle problems with uncertainty, nonlinear dynamics and constraints. The developed techniques include data-driven approaches and novel model predictive control techniques. The latter are based either on set membership models, in an adaptive context, or on randomization methods;
2. new identification approaches have been investigated in conjunction with data-driven control design techniques, moreover a novel method to simulate and analyze stochastic dynamical systems has been developed, based on polynomial chaos expansions;
3. advanced techniques based on direct virtual sensors and moving horizon estimation concepts have been developed, and novel sensor fusion algorithms for airborne wind energy have been conceived and tested experimentally;
4. filtering and control algorithms have been implemented in real-world experiments concerned with airborne wind energy;
5. significant experimental activities have been carried out in the field of airborne wind energy, by using a small-scale prototype completely developed and built during the project (a picture of the prototype is attached, while a movie of the tests is available online at http://youtu.be/2ek65AiIkqM).
In addition to the mentioned research activities, the fellow also carried out important training activities, by attending advanced courses and schools both at UCSB and at international locations, as well as dissemination activities through participation to international conferences. He also gave seminars at major universities and research centres including UC Berkeley, UC Boulder, NREL, EPF Lausanne, ETH Zurich, University of Stuttgart, ABB Corporate Research Zurich.
Finally, the fellow successfully applied for a grant awarded by the California Energy Commission amounting to $95,000 for one year, to carry out experimental activities in the field of airborne wind energy. He successfully managed the grant, achieving the prescribed goal of at least four consecutive hours of autonomous flight of a flexible tethered wing.
The results of the research activities include 17 papers published or accepted for publication on peer-reviewed international journals in the field of controls and 6 papers currently under review, as well as 1 book chapter and 21 papers published or accepted for publication in peer-reviewed international conference proceedings. Moreover, the successful experimental activities demonstrated the feasibility of automatic control of tethered wings for airborne wind energy and allowed to collect a significant amount of data. In particular, the developed control system for tethered wings is one of the few in the world whose successful operation has been demonstrated, and the first that has been published in detail together with extensive experimental data.
Finally, thanks to this research project the fellow was able, towards the end of the return phase, to secure a long-term job in the field of research within the European research area, in particular in a private research institute in Switzerland, hence fulfilling one of the main objectives of the Marie Curie funding scheme.