|
Centre for Automation and Robotics |
|
| Home | Projects |
|
|
ATLAS
NEW ACTUATION AND CONTROL TECHNOLOGIES FOR EMPOWERING HUMANS AND ROBOTS Spanish Ministry for Innovation and Science (DPI2010-18702) In the last years a new
generation of legged-locomotion robots is atracting the interest of
researchers
of a broad range of areas because of its potential impact in the
society of the
future. Lower-limb exoskeletons and
active orthoses are robotic devices worn by an operator that fit closely and
operate in parallel with the
human legs, and are the best choice for augmenting human performance in
urban,
industrial, and natural scenarios. Exoskeletons and active orthoses are
expected to help the user walk (and even run) while carrying the
human’s weight
and additional payload. The potential benefits of these robotic devices
in
assisting physically challenged persons are impressive. However, in
spite of
the research effort on the subject, there are very few prototypes having the envisaged
performance. The major challenges that
limit their performance are:
(1) The need for energetic autonomy for long periods, (2) as portable devices they have to include all actuators and power source, (3) The requirement of large actuation power, (4) The requirement of being light-weight devices, and (5) they have to safely interact with the human user. These five requirements cannot be met with conventional actuation technology. This builds up a new line
of research aimed at designing energy efficient, large power-to-weight
actuators and energy-efficient-locomotion control schemes for the new
generation of legged robots. This project aims
at establishing this new long-term research by reaching three main
goals: The
first goal is to research, design
and develop novel actuators capable of delivering
the large power to
weight requirements of exoskeletons. The second goal of the project is to study how
to achieve energy efficiency
in the control of locomotion. The
combination of passive dynamics (making use of elastic elements for
storing
energy along some phases of the gait cycle) with the use of
controllable
resistive actuators for achieving variable compliance along the gait
cycle,
should allow to provide active actuation only when it is needed to
infer power
to the system. This will be the means to optimize power consumption and
enlarge
the autonomy of the robot. To show the benefits of the research on new
actuators
and control schemes,
the ultimate goal of the project is to design, develop and test an
active orthosis for a quadriplegic child. The device will
produce her motions in everyday-life activities (stand up, sit down,
walk
stably). The DCA of the CAR (previously IAI-CSIC)
exhibits
extensive expertise in the design, development and control of
legged-locomotion
robots and it is leading the research since 20 years ago.
The ATLAS Lower-Limb Exoskeleton for Gait Assistance in Quadriplegia The
ATLAS exoskeleton falls within the classification of active orthosis as
it is devised for gait assistance, not for load-carrying augmentation.
In orthotic terminology it can be considered as an active THKAFO
(Trunk- Hip-Knee-Ankle-Foot Orthosis). ATLAS is intended to support a
25-kg girl and help her out with walking at a moderate speed
(<1m/s). The particular pathology of ATLAS' user is
quadriplegia:
she is a 8 year-old girl affected by paralysis of both legs and arms
(the girl can only move her left hand). This paralysis was caused by
spinal cord injury, and therefore, she cannot move her extremities, and
she cannot control the torso to keep balance. Besides, biological
signals from the motor cortex do not reach the extremities in
quadriplegic patients. Therefore, in order to command the motion of the
exoskeleton, biosignals cannot even be acquired through typical
non-invasive methods used in exoskeletons, such as Electro-miogram.
With all this in mind, the ATLAS exoskeleton has been thought of as a
lightweight, easy to handle and to put on robotic system composed of
the following main components, sketched in Figure 1.
 Figure 1. Conceptual sketch of the ATLAS exoskeleton
Publications 1.- Arevalo, J.C and Garcia, E. "Impedance Control for Legged Robots: An insight into the Concepts Involved" IEEE Transactions on Systems Man and Cybernetics, (IN PRESS). 2.- E. Garcia, D. Sanz-Merodio, F. Sanchez, J.C. Arevalo and P. Gonzalez de Santos, Development of the ATLAS lower-limb active orthosis, 14th Int. Conf. Climbing and Walking Robots and the Support Technologies for Mobile Machines, Field Robotics ISBN: 13 978-981-4374-27-9 Paris, France, 2011 |
|
Field and Service Robotics Group :: Applied Robotics Department :: Centre for Automation and Robotics :: Spanish National Research Council |
|
