Meccanica Magazine n. 4

meccanica magazine
36
ENG
The DIGES project: DIGital twin project of Lunar Exploration Systems
DIGES is a research project between the Italian Space Agency (ASI)
and the Politecnico di Milano (POLIMI) aimed at developing a preliminary
design of a Digital-Twin (DT) model of space rover systems for
lunar surface exploration.
Space exploration has always been of interest equally for the scientific
and civil society for both its inner charm, which always nourished
the human fantasy, and for the scientific opportunities that
from it might arise. Among the different phases of space exploration,
the analysis of the surface of those celestial objects plays a
central role, both for a greater understanding of the formation of the
solar system and the universe in general, and for the ancient desire
of man to find traces of new life forms. In this context, the Moon was
the first target of a space exploration, which, more recently, has also
extended to other celestial bodies, in particular through the use of
rovers (think for example of the exploration of the surface of Mars).
Rovers allow exploring the surface by collecting samples of scientifically
valuable material, such as ambient images and data, rock samples,
etc. Clearly, the role played by the rovers has become crucial
and that their reliability is fundamental to the success of the mission
itself. Nowadays, the high complexity and costs of these exploration
platforms call for high reliability and efficiency, even operating autonomously.
In fact, the possibility of unexpected failures, anomalies,
or performance degradation (usually unavoidable) could give rise to
consistent losses and catastrophic consequences, especially due
to the impossibility of direct human interventions. In order to avoid
that failures or anomalies compromise the success of the mission,
the scientific community, supported by the industries of the sector,
recently developed a series of advanced technologies that can
be applied to the remote and real-time health monitoring of the rover.
Among others, the development of a detailed DT model of the
system turns out essential, being able to accurately reproduce the
operation of the rover, and to simulate the signals acquired through
the on-board sensors, by modeling the multi-physical interactions
between the different subsystems, thus allowing a more informed
management of the system throughout its life cycle operating. To
this aim, the research group of the Department of Mechanical Engineering
will provide its major contribution. Leveraging on the
activities carried out in the past, our research group has already developed
Health and Usage Monitoring Systems (HUMS) for complex
platforms applications, especially for the aeronautical industry. This
methodology makes use of DT models, which in the DIGES project
can be used in order to optimize both the design of the systems and
their operational management. In particular, the methodology can
be used in different stages of the rover’s life, including:
- the design phase,
- the testing phase,
- the operational and decision-making phase of the mission,
- the residual life optimization phase.
The project therefore proposes the preliminary development of a
DT architecture for a rover-type space system for lunar exploration.
This DT will be based on the creation of multi-physical models, representative
of the spatial system, to be used for the generation of
characteristic patterns useful for the interpretation of the signals
acquired in real time, both in healthy and damaged / anomalous conditions.
These will be processed by artificial intelligence algorithms
and, more generally, by statistical signal processing, in order to return
a real-time “photograph” of the system. In this context, three
main project objectives will ensure the future implementation of the
technology on real platforms:
- the model must have a relatively low computational weight allowing
real-time access, possibly through the implementation of
surrogate models.
- the model must be able to adapt immediately and autonomously
to the inevitable changes occurring during operation phases, which
will be possible via the implementation of model-updating/filtering
algorithms.
- the model must be able to interact with other DT models, as those
related to other space modules or representing the interaction with
the lunar surface, etc.
The achievement of these objectives is expected to ensure faster
planning and greater reliability of future missions to explore the lunar
soil and other celestial bodies in general.
The project is coordinated by the multidisciplinary research group
of the Department of Mechanical Engineering of the Politecnico di
Milano, with strong experience in project management in the field of
monitoring and prognostics of mechanical and aerospace structures
and systems. The research team is made up of Prof. Marco Giglio,
Prof. Claudio Sbarufatti and Prof. Francesco Cadini, active in
the fields of multi-physics modeling and artificial intelligence, and
will also involve PhD students, MSc students and researchers.