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Bioinspired Vision-based Microflyers
Taking inspiration from biological systems to enhance navigational autonomy
of robots flying in confined environments.
The goal of this project is to develop control
strategies and neuromorphic chips for autonomous microflyers capable of
navigating in confined or cluttered areas such as houses or small built
environments using vision as main source of information.
Flying in such environements implies a number of challenges that are not
found in high-altitude, GPS-based, unmanned aerial vehicles (UAVs). These
include small size and slow speed for maneuverability, light weight to stay
airborne, low-consumption electronics, and smart sensing and control. We
believe that neuromorphic vision chips and bio-inspired control strategies
are very promising methods to solve this challenge.
The project is articulated along three, tightly integrated, research
directions:
Mechatronics of indoor microflyers (Adam Klaptocz, EPFL);
Neuromorphic vision chips (Rico Möckel, INI);
Insect-inspired flight control strategies (Antoine Beyeler, EPFL).
We plan to take inspiration from flying insects both for the design of the
vision chips and for the choice of control architectures. Instead, for the
design of the microflyers, we intend to develop innovative solutions and
improvements over existing micro-helicopter and micro-airplanes.
Our final goal is to better understand the minimal set of mechanisms and
strategies required to fly in confined environments by testing theoretical
and neuro-physiological models in our microflyers. A 10-gram microflyer
that flies autonomously in a 7x6m test arena
The purpose of this ongoing experiment is to demonstrate autonomous steering
of a 10-gram microflyer (the MC2) in a square room with different kind of
textures on the walls (the Holodeck). This will first be achieved with
conventional linear cameras before migrating towards aVLSI sensors.
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Artist's view of the project
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Microflyer
The fully autonomous 10-gram MC2 equiped with 2 linear
CMOS cameras, 2 rate gyros, an anemometer, an 8-bit microcontroller and a
Bluetooth radio module.
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Evolution of Analog Networks: Analog Genetic Encoding
(AGE)
Evolutionary Synthesis and Reverse Engineering of Complex Analog Networks
The synthesis and reverse engineering of analog
networks (see sidebar) are recognized as knowledge-intensive activities,
where few systematic techniques exist. Given the importance and
pervasiveness of analog networks, there is a founded interest in the
development of automatic techniques capable of handling both problems.
Evolutionary methods appear as one of the most promising approaches for the
fulfillment of this objective.
Analog Genetic Encoding (AGE) is a new way to represent and evolve analog
networks. The genetic representation of Analog Genetic Encoding is inspired
by the working of biological genetic regulatory networks (GRNs). Like
genetic regulatory networks, Analog Genetic Encoding uses an implicit
representation of the interaction between the devices that form the network.
This results in a genome that is compact and very tolerant of genome
reorganizations, thus permitting the application of genetic operators that
go beyond the simple operators of mutation and crossover that are typically
used in genetic algorithms. In particular, Analog Genetic Encoding permits
the application of operators of duplication, deletion, and transpositions of
fragments of genome, which are recognized as fundamental for the evolution
and complexification of biological organisms. The resulting evolutionary
system displays state-of-the-art performance in the evolutionary synthesis
and reverse engineering of analog networks.
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The AGE Genome
The AGE genome is constituted by one or more strings of
characters (called chromosomes) from a finite genetic alphabet. The
experimenter defines a device set which specifies the kind of devices that
can appear in the network. For example, the device set of an evolutionary
experiment aimed at the synthesis of an analog electronic circuit could
contain a few types of transistors, and the device set of an evolutionary
experiment aimed at the synthesis of a neural network could contain a few
types of artificial neuron models. The experimenter specifies also the
number of terminals of each kind of device. For example, a bipolar
transistor has three terminals, a capacitor has two terminals, and an
artificial neuron could be specified as having one output terminal and one
input terminal. The AGE genome contains one gene for each device that will
appear in the network decoded from the genome, as shown in the figure
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Decoding the AGE Genome
Analog Genetic Encoding specifies the regions of the
genome which correspond to the devices and to their terminals and parameters
by means of a collection of specific sequences of characters that we call
tokens. One specific device token is defined by the experimenter for each
element of the device set. The device token signals the start of a fragment
of genome that encodes an instance of the corresponding device. The
experimenter defines also a terminal token, which delimits the sequences of
characters that are associated with the terminals. The interaction between
genes is represented in terms of a device interaction map I, which
transforms pairs of character sequences associated with two distinct device
terminals, into a numeric value that characterizes the link connecting the
two terminals. The final result is an analog network decoded from the
genome, as shown in the animation
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Evolution of Communication
Exploring the emergence and evolution of communication in social animals
using collective, evolutionary robotics
The aim of this project is to address questions on the
emergence and evolution of communication in groups of social animals by
using evolutionary robotics to build societies of autonomous robots that
evolve a communication system to solve a particular survival task
collectively. Our work is part of the ECAgents project, sponsored by the
Future and Emerging Technologies program of the European Community
(IST-1940), whose aim is to develop embodied agents capable of interacting
with the physical world, including other agents and humans through the use
of communication. In previous and current work we have focused on the
following issues:
- The pre-requisites for communication
- Conditions for the emergence of communication
- The transition to symbolic communication
- Social learning and the evolution of communication
Method
In order to tackle these questions, we evolve neural networks for a
population of agents required to solve a survival task of foraging for food
and avoiding poison. Artificial evolution takes place under a physics-based
simulated environment Enki, where both the robots' sensors and actuators and
the experimental setup are modelled. An evolutionary robotic framework Teem
is then used to evolve the best controllers to survive in this simulated
environment, which are then transferred onto real robots. The resulting
behaviours are compared to biological models and used to answer various
theoretical questions, such as those listed above.
Robots
As a tool for demonstrating various communication mechanisms in artificial
systems between groups of robots, two types of robots are being used within
this project. The first robot, the s-bot was originally designed for the
swarm-bots project (Mondada et al. 2003), which aims to study the self-organisation
and self-assembly of groups of robots. The design of the robot was slightly
modified in order to fit the requirements of a demonstrator for artificial
communication.
Main Findings
The conditions for the emergence of communication were explored in
experiments where two parameters were monitored for their influence on the
emergence of communication (see Fig. 1, left):
1. Genetic relatedness within a group of robots (homogeneous, r=1, vs.
heterogeneous, r=0, colonies)
2. Level of evolutionary selection (individual or group)
Our results show that honest communication evolves in three of the four
tested conditions, thereby increasing fitness compared to a baseline
experiment, where no blue light was allowed (see Fig. 1, right). The robots
evolved two different stable communication strategies, which were not
equally efficient: In the first, they signalled when by the food, whereby
receivers evolved an attraction to blue light (Fig. 2, left). In the second
strategy, less efficient strategy, signallers emitted light by the poison,
while receivers were repelled by blue light (Fig. 2, right). This shows that
evolved communication systems need not be optimal in order to be stable.
When agents were unrelated and selected individually, we observed that
communication reduced the fitness of the groups. Further investigation
revealed that this was caused by the spread of deceptive communication. Due
to the large amount of competition between individuals, it was in the
signallers’ best interest to reduce the fitness of receivers. This was done
by signalling far from the food, given that individuals were attracted to
blue light. One might expect that this would lead receivers to cease to be
attracted to blue light. However, this does not occur. The receiving
strategy is very stable, in conjunction with the deceptive signalling
strategy.
Our hypothesis is that the stability of deceptive communication is due to a
large amount of noise in the selection process. Receivers remain attracted
to blue light because there are always some signallers in the population
that signal by the food. Thus, there was always enough blue light by the
food to make it worth following. These results are currently under
investigation.
In conclusion, we show that in order for honest communication to evolve,
either genetic relatedness or group-level selection is needed. Furthermore,
we show that the use of realistic models can lead to dynamics (such as the
stability of deceptive communication) that one would not observe in
simplified mathematical or game-theoretical models.
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s-bots
The s-bots have a diameter of 12 cm and a height of 15cm
and possess 2 Lilon batteries, which give it about an hour of autonomy. A
400 MHz custom Xscale CPU board with 64 MB of RAM and 32 MB of flash memory
is used for processing, as well as 12 distributed PIC microcontroller for
low-level handling.
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Fig. 1. Left: Four conditions tested in our experiments.
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Fig. 1. Right: Comparison of mean performance with and
without communication in the four cases.
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Fig. 2. Left: Evolved food signalling strategy.
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Fig. 2. Right: Evolved poison signalling strategy
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The Eyebots
'A new swarm of indoor flying robots capable of operating in synergy with
swarms of foot-bots and hand-bots'
Eyebots are autonomous flying robots with powerful
sensing and communication abilities for search, monitoring, and pathfinding
in built environments. Eyebots operate in swarm formation, as honeybees do,
to efficiently explore built environments, locate predefined targets, and
guide other robots or humans.
Eyebots are part of the Swarmanoid, a European research project aimed at
developing an heterogeneous swarm of wheeled, climbing, and flying robots
that can carry out tasks normally assigned to humanoid robots. Within the
Swarmanoid, Eyebots serve the role of eyes and guide other robots with
simpler sensing abilities.
Eyebots can also be deployed on their own in built environments to locate
humans who may need help, suspicious objects, or traces of dangerous
chemicals. Their programmability, combined with individual learning and
swarm intelligence, makes them rapidly adaptable to several types of
situations that may pose a danger for humans.
Eyebots are currently under development at LIS, EPFL. We will post
additional information on this site as soon as technical documents will be
available for public disclosure.
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The Eyebots
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Self Deploying Microglider
Developing a hybrid robotic vehicle capable of deploying itself into the air
and perform goal directed gliding
Gliding flight is powerful -to overcome obstacles and
travel from A to B.
It can be applied in miniature robotics as a very versatile and easy to use
locomotion method. In this project we aim at developing a palm sized
Microglider that possesses the ability to deploy from ground or walls, to
then open its wings, recover from almost every position in mid-air and
perform subsequent goal directed gliding.
A potential source of inspiration on how to accomplish this task efficiently
is nature. In the animal kingdom, many small animals are able to get into
the air by jumping, fast running or by dropping down from trees. Once
air-borne, they recover and stabilize passively or actively and perform goal
directed aerial descent (e.g. gliding frogs, flying geckos, gliding lizards,
locusts, crickets, flying squirrels, gliding fish, gliding ants etc.). These
animals do not use steady state gliding, but change their velocity and angle
of attack dynamically during flight to optimize the trajectory in order to
increase the gliding ratio or land on a spot. The same principles may be
advantageous for small aerial robots as well.
The critical issues on the path towards the realization of an efficient
deploying Microglider at this scale are (i) the trade-off between passive
stability, maneuverability and maximal gliding ratio, (ii) the low Reynolds
number (<10'000) that leads to increased influence of boundary layer effects
and renders the applicability of the conventional and well known large scale
aerodynamics impossible and (iii) the control of the unsteady dynamics
during recovery and flight.
The work in progress addresses these aspects. Embedded mechanisms for
autonomous deployment from ground or walls into the air will be considered
at the next stage.
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A miniature 7g jumping robot
Jumping can be a very efficient mode of locomotion for
small robots to overcome large obstacles and travel in natural, rough
terrain. As the second step towards the realization of the the Self
Deploying Microglider, we present the development and characterization of a
novel 5cm, 7g jumping robot. It can jump obstacles as high as more than 24
times its own size and outperforms existing jumping robots with respect to
jump height per weight and jump height per size. It employs elastic elements
in a four bar linkage leg system to allow for very powerful jumps and
adjustment of jumping force, take off angle and force profile during the
acceleration phase.
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A 1.5g SMA actuated Microglider looking for the Light
As a first step towards the exploration of gliding as an
alternative or complementary locomotion principle in miniature robotics, we
developed a 1.5g ultra light weight microglider. It is equipped with sensors
and electronics to achieve phototaxis (flying towards the light), which can
be seen as a minimal level of control autonomy. To characterize autonomous
operation of this robot, we developed an experimental setup consisting of a
launching device and a light source positioned 1m below and 4m away with
varying angles with respect to the launching direction. Statistical analysis
of 36 autonomous flights indicate its flight and phototaxis efficiency.
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Solar Impulse: Human-Machine Interface - Body Sensing
An adaptive wearable device for monitoring sleep and preventing fatigue
Fatigue is a major source of stress and accidents in
today's world, but there are no objective ways of monitoring and preventing
the build-up of fatigue.
Sleep and wake periods are major factors, but not the only ones, that
contribute to regulate the onset of fatigue. In this project, we start by
developing a non-intrusive, wearable device for monitoring sleep and wake
phases.
Since body signals related to sleep and wake are different from person to
person, our device incorporates learning technologies adapted from our work
on autonomous robotics. This allows the device to self-tune to the user.
The output of the sleep/wake device will then be incorporated into a model
of fatigue that takes into account also other body signals and can adapt to
the style and physiology of the user.
A version of the sleep/wake device will be tested within the framework of
Solar Impulse, where the pilot has to be alert during the entire flight,
which can take up to five days and nights. Our device can be used to predict
the pilots fatigue and to calculate his optimal break times, always taking
into account the mission status.
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Title
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The Solar Impulse plane flying above the EPFL campus (fotomontage)
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The SMAVNET project
Swarming Micro Air Vehicle Networks for Communication Relay
We aim at designing a swarm of Micro Air Vehcles (SMAVs)
capable of autonomously establishing emergency wireless networks (SMAVNETs)
between multiple ground-users in a disaster area. The SMAVNET is required to
be rapidly deployable in any environment following the paradigms of swarm
robotics. MAVs are designed to be minimal (low-cost, light-weight, simple
electronics) and do not use position sensors (cameras, GPS), which are
dependent on the environment, expensive in terms of energy, cost, size and
weight or unusable at large ranges. Rather than that, agents rely on local
communication with immediate neighbors and proprioceptive sensors which
provide heading, speed, altitude and angular velocities. Such SMAVNETs
could replace damaged, inexistent or congested networks and can play an
important role in disaster mitigation. The aerial nature of the system is
interesting in that it allows for line-of-sight transmissions between MAVs,
which is more energy-efficient than communication in cluttered environments
at ground level. Furthermore, MAVs can fly over difficult terrain such as
flooded areas or debris.
In the scope of the SMAVNET project we are developing a generic MAV platform
usable in most aerial robotic applications. The construction of 10 to 20 of
these MAVs will serve as a demonstration platform for developed SMAVNET
swarm algorithms.
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Evolved Swarm Control (2D)
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| Offer Profile |
The Laboratory of Intelligent Systems
The Laboratory of Intelligent Systems (LIS) directed by Prof. Dario Floreano
focuses on the development of robotic systems and artificial intelligence
methods inspired by biological principles of self-organization. Currently, we
address three interconnected research areas:
Flying Robots
We have developed a series of vision-based robots, with weights between 1.5 and
30 grams, capable of flying indoor without human intervention. Current research
efforts focus on shape, aerodynamics, mechatronics, vision processing, and
control of such machines. Biological inspiration in mechatronic design,
materials, and control allowed us to break several world records in miniaturized
autonomous flyers. Such robots include both wing and rotor based systems, as
well as jumping gliders. They operate either as individual units or in swarm
formation. In addition to indoor flying robots, outdoor flying robots (less than
300g) are being developed that won't need GPS or classic autopilot systems for
autonomous navigation.
Artificial Evolution
We have developed several novel approaches to artificial evolution of complex
embedded systems characterized by non-linear interactions of multiple hardware
and software components. The application to robotics, known as Evolutionary
Robotics, is a classic specialty of the laboratory. Current research efforts aim
at evolutionary synthesis of analog electrical circuits, learning neural
controllers, reverse engineering of biological networks (genetic and metabolic
networks), and biomedical signal processing.
Social Systems
In collaboration with evolutionary and behavioral biologists, we have
synthesized methods for control of systems composed of multiple agents and
processes that can display altruistic cooperation, division of labor, and
communication. These methods are applied and developed in teams of robots
(wheeled and flying) as well as to the investigation of biological theories of
emergence of cooperation and communication in insect societies. Current efforts
are aimed at development of novel hardware and control methods that can profit
from such developments, such as multiple and expendable robots for search and
rescue, monitoring, and exploration of areas dangerous for humans. |
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