@article{AF_Franceschini_090319,
Title={Towards automatic visual guidance of aerospace vehicles: from insects to robots},
Author={Francescini, N.},
Journal={Acta Futura},
Pages={12-28},
Abstract={Equipped with a less-than-one-milligram brain, insects fly autonomously in
complex environments without resorting to any Radars, Ladars, Sonars or GPS.
The knowledge gained during the last decades on insects' sensory-motor
abilities and the neuronal substrates involved has provided us with a rich
source of inspiration for designing tomorrow's self-guided vehicles and
micro-vehicles, which are to cope with unforeseen events on the ground, in the
air, under water or in space. Insects have been in the business of
sensory-motor integration for more than 100 millions years. They can teach us
useful tricks for designing agile autonomous vehicles at various scales.
Constructing a ``biorobot'' first requires exactly formulating the signal
processing principles at work in the animal. It gives us, in return, a unique
opportunity of checking the soundness and robustness of those principles by
bringing them face to face with the real physical world. Here we describe some
of the visually-guided terrestrial and aerial robots we have developed on the
basis of our biological findings. All these robots react to the optic flow
(i.e., the angular speed of the retinal image). Optic flow is sensed onboard
the robots by miniature vision sensors called Elementary Motion Detectors
(EMDs). The principle of these electro-optical velocity sensors was derived
from optical/electrophysiological studies where we recorded the responses of
single neurons to optical stimulation of single photoreceptor cells in a model
visual system: the fly's compound eye. Optic flow based sensors rely solely on
contrast provided by reflected (or scattered) sunlight from any kind of
celestial bodies in a given spectral range. These passive sensors and systems
offer potential applications to manned or unmanned spacecraft, from robotic
landers and rovers to asteroid explorers and satellite docking, with
interesting prospects in weight- reduction and low consumption.
},
Url={http://dx.doi.org/10.2420/AF03.2008.12},
Volume={3},
Year={2008}
}
@article{AF_Saffiotti_090319,
Title={The Concept of Peis-Ecology: Integrating Robots in Smart Environments },
Author={Saffiotti, A.},
Journal={Acta Futura},
Pages={29-35},
Abstract={The concept of Ecology of Physically Embedded Intelligent Systems, or
Peis-Ecology, combines insights from the fields of ubiquitous robotics
and ambient intelligence to provide a new solution to building intelligent
robots in the service of people. In this note I introduce this concept,
summarize its main technological aspects, and speculate on its potential impact
for space exploration.
},
Url={http://dx.doi.org/10.2420/AF03.2008.29},
Volume={3},
Year={2008}
}
@article{AF_Zauner_090319,
Title={Integration of Cellular Biological Structures Into Robotic Systems},
Author={Gough, J. and Jones, G. and Lovell, C. and Macey, P. and Morgan, H. and Revilla, F.D. and Spanton, R. and Tsuda, S. and Zauner, K.P.},
Journal={Acta Futura},
Pages={36-41},
Abstract={},
Url={http://dx.doi.org/10.2420/AF03.2008.36},
Volume={3},
Year={2008}
}
@article{AF_Beeby_090319,
Title={Kinetic Energy Harvesting},
Author={Beeby, S.P. and Torah, R.N. and Tudor, M.J.},
Journal={Acta Futura},
Pages={44-51},
Abstract={This paper reviews kinetic energy harvesting as a potential localised power
supply for wireless applications. Harvesting devices are typically implemented
as resonant devices of which the power output depends upon the size of the
inertial mass, the frequency and amplitude of the driving vibrations, the
maximum available mass displacement and the damping. Three transduction
mechanisms are currently primarily employed to convert mechanical into
electrical energy: electromagnetic, piezoelectric and electrostatic.
Piezoelectric and electrostatic mechanisms are best suited to small size MEMS
implementations, but the power output from such devices is at present limited
to a few microwatts. An electromagnetic generator implemented with discrete
components has produced a power 120~W with the highest recorded efficiency to
date of 51\% for a device of this size reported to date. The packaged device is
0.8~cm$^3$ and weighs 1.6~grams. The suitability of the technology in space
applications will be determined by the nature of the available kinetic energy
and the required level of output power. A radioactively coupled device may
present an opportunity where suitable vibrations do not exist.
},
Url={http://dx.doi.org/10.2420/AF03.2008.44},
Volume={3},
Year={2008}
}
@article{AF_Halme_090319,
Title={Biomass Based Fuel Cells - Application to Manned Space Exploration},
Author={Halme, A.},
Journal={Acta Futura},
Pages={52-57},
Abstract={Long-term energy-demanding operations in remote off-the-grid locations, like in
space exploration, require small, lightweight energy storage and power sources
that are able to remain functionable over long periods of time. In manned
flights human secretions represent a potential source of methane and hence
hydrogen, which can be used as fuel in fuel cells, or in propellant gas
mixtures. Processing those secretions together with other biological waste
provides fuel from available resources thus reducing fuel transportation from
Earth and contributing to waste disposal in long missions, like Mars
exploration. Fuel cells, in particular biocatalyzed fuel cells, offer a
potential solution to the problem of generating electricity from the available
energy with the aid of bacteria. They convert readily available substrates from
renewable sources such as cereal materials, vegetable, fruits, fish meat and
even human waste, to electricity and useful by-products such as water. Since
the biocatalyzed fuel cells use concentrated sources of chemical energy, they
can be small and lightweight, which is a crucial matter in the space
application. There are in principle three ways to convert the biological
energy available into electricity and heat. One way is to use traditional
anaerobic digestion in order to produce methane and then further process it to
electricity/heat by the aid of high a temperature fuel cell like SOFC. Both of
these technologies are already available at a practical level, although
application to the space environment needs further development. The second way
is to use a bacterial biological fuel cell for direct electricity production.
This technology is fairly new, but has already been the subject of experiments
in several practical tests. The third way is to use biocatalyzed electrolysis
or reforming to produce hydrogen directly, which can then be further processed
into electricity with the aid of a low temperature fuel cell, like PEM. This is
a very new, but promising innovation, which still needs research to prove it's
feasibility. This paper makes a short introduction to the underlying technology
and compares the energy balance of the two first mentioned ways to recover
electricity from biological waste recycling in an imaginary case, where six
astronauts live in a micro ecological life supporting system during their Mars
mission.
},
Url={http://dx.doi.org/10.2420/AF03.2008.52},
Volume={3},
Year={2008}
}
@article{AF_Pelaez_090319,
Title={Orbital energy of natural satellites converted into permanent power for spacecraft},
Author={Peláez, J.},
Journal={Acta Futura},
Pages={58-65},
Abstract={},
Url={http://dx.doi.org/10.2420/AF03.2008.58},
Volume={3},
Year={2008}
}
@article{AF_Yakovlev_090319,
Title={Harnessing of the power of the solar wind particles captured in the Van Allen belts},
Author={Kolesnikov, E.K. and Yakovlev, A.B.},
Journal={Acta Futura},
Pages={66-71},
Abstract={The feasibility of constructing a high-voltage electric generator (HEG) transforming kinetic energy of particles from the radiation belts into electric power is considered. The maximum specific power of the generator is theoretically evaluated for particular cases of setting it inside the natural radiation belts of the Earth (ERB) and in polar region. It is demonstrated that from the viewpoint of weight parameters, the suggested design of the HEG is quite competitive with power sources of low-thrust spacecraft operating on conventional principles.
},
Url={http://dx.doi.org/10.2420/AF03.2008.66},
Volume={3},
Year={2008}
}
@article{AF_Duwez_090319,
Title={Playing with forces and interactions to manipulate single molecules},
Author={Menaa, B. and Duwez, A.S.},
Journal={Acta Futura},
Pages={74-78},
Abstract={Molecular manufacturing is a technology that will allow us to assemble molecular machines and build complex objects atom by atom. The use of scanning probe microscopy-based techniques to manipulate single molecules, to detect binding processes, or to deliver molecules in a precisely controlled manner to a specific target represents a significant step in that direction. It requires the controlled formation and breaking of individual bonds.
Here we show that the atomic force microscope (AFM) can deliver and immobilize single molecules, one at a time, on a surface. Reactive polymer molecules, attached at one end to an AFM tip, are brought into contact with a substrate to which they become linked by a chemical reaction. When the AFM tip is pulled away from the surface, the resulting mechanical force causes the weakest bond the one between the tip and polymer to break. This process transfers the polymer molecule to the substrate.
We also show examples of the use of those AFM tips bearing reactive polymers for molecular recognition applications. We have covalently attached proteins or ligands to those tips to obtain probes sensitive to specific molecular interactions.
We can imagine that the functional principles and concepts found in molecule manipulation by AFM, i.e. playing with mechanical forces, with strong and weak complementary interactions, could be implemented to attach and detach units in the space field.
},
Url={http://dx.doi.org/10.2420/AF03.2008.74},
Volume={3},
Year={2008}
}
@article{AF_Pettazzi_090319,
Title={Electrostatic Force for Swarm Navigation and Reconfiguration},
Author={Pettazzi, L. and Krüger, H. and Theil, S. and Izzo, D.},
Journal={Acta Futura},
Pages={80-86},
Abstract={In this work the concept of a swarm of satellites controlled by a hybrid thrusting electrostatic actuation system is assessed. On one side the propulsion system is investigated. First from the model of the interaction between the space plasma and a charged spacecraft a set of requirements is derived. This allows to define an actuation system for charge control. Then the applicability of the electrostatic actuation for formation keeping and reconfiguration of swarms of satellites is assessed. In particular this work aims at demonstrating that the electrostatic actuation can be exploited in a decentralized control scheme to trigger high fuel savings in reconfiguration maneuvers of swarms of satellites. To this end a novel charging strategy has been developed. The resulting system has been tested under different possible simulations and it has shown good performances in terms of reduction of the fuel expenditure for the whole swarm.
},
Url={http://dx.doi.org/10.2420/AF03.2008.80},
Volume={3},
Year={2008}
}
@article{AF_Sabatini_090319,
Title={Invariant Relative Satellite Motion},
Author={Sabatini, M. and Izzo, D. and Palmerini, G.},
Journal={Acta Futura},
Pages={87-93},
Abstract={Formation flying is a key technology enabling a number of missions which a single satellite cannot accomplish: from remote sensing to astronomy and fundamental physics. The design of relative navigation and control systems of the spacecraft is certainly one of the most challenging topic. In order to ease the tasks of these subsystems, a proper reference trajectory must be conceived, and a relative motion, which shows no drift even in presence of a large disturbance as the $J_2$ effect, could be a very attractive solution. This paper describes the research activities for finding invariant relative orbits under J2 effect. Numerical tools as genetic algorithms enabled the discovery of two special inclinations which represent the necessary conditions for periodicity of the motion. These results generated interest, and analytical explanations for the numerical evidence have been proposed: on-going studies face this problem from different points of view, and basic results are reported.
},
Url={http://dx.doi.org/10.2420/AF03.2008.87},
Volume={3},
Year={2008}
}
@article{AF_Sala_090319,
Title={Pulsar Navigation},
Author={Sala, J. and Urruela, A. and Villares, X. and Romeu, J. and Blanch, S.},
Journal={Acta Futura},
Pages={94-101},
Abstract={This paper evaluates the fundamental performance bounds, signal
processing and technological complexity associated with the
synchronization to radio and X-ray pulsars as well as its impact on
the positioning accuracy of an autonomous spacecraft navigation
system. Performance analysis of synchronization and location
algorithms builds on Maximum Likelihood (ML) estimation which
provides, asymptotically, unbiased minimum variance estimates with
mean square error strictly approaching the Cramer-Rao Lower Bound
(CRLB).
},
Url={http://dx.doi.org/10.2420/AF03.2008.94},
Volume={3},
Year={2008}
}
@article{AF_Seidl_090319,
Title={Insect navigation and path finding},
Author={Seidl, T.},
Journal={Acta Futura},
Pages={102-106},
Abstract={Insects have a brain weighing about a tenth of a milligram. Nevertheless some
insect species exhibit amazing performance in finding their daily paths when
looking for food or shelter. Some species have even found their ecological
niche in being excellent navigators and hence can survive in extreme habitats.
One remarkable and well studied model is the Saharan desert ant
Cataglyphis fortis that outruns its competitors by performing
egocentric navigation. By using skylight cues as a compass and counting steps
it is able to find its way without using external visual cues. In comparison,
the Australian desert ant Melophorus bagoti employs route learning
strategies, where it visually learns and in tests recalls every point of their
route. In studying the insects' strategies we can learn a great deal on how
little information can be used to perform a navigational task. Also the way of
how information is processed within such a tiny brain is intriguing. The
conclusions drawn from this research are nowadays not only used to understand
human behavior but find their way into technical design.
},
Url={http://dx.doi.org/10.2420/AF03.2008.102},
Volume={3},
Year={2008}
}