Page 291 - Handbook of Biomechatronics

284 Andres F. Ruiz-Olaya et al.

biology, which refers to systems that expand or augment a person’s physical
abilities (Kazerooni, 2008). For instance, those devices help a person lift or
carry heavier loads, run faster, and jump higher. Table 1 shows an analogy
between the biological exoskeleton and the exoskeleton system in the engi-
neering field, and their potential applications. Upper and lower exoskeletons
could offer humans the kind of protection, support, enhancement, and
sensing which they afford in nature.
Exoskeletons have segments and joints that correspond to some extend
to those of the human body (Fig. 1). Those devices can be seen as a tech-
nology to extend, complement, substitute, or enhance the human function
and capability or to empower the human limb where it is worn out
(Maciejasz et al., 2014). There is a one-to-one correspondence between
human anatomical joints and the robot joints or sets of joints. This kinematic
compliance is a key aspect in achieving ergonomic human-robot interfaces.
Taking into account that humans and exoskeletons are in close physical
interaction, there is an effective transfer of power between the human
and the robot (Ruiz et al., 2008).

1.2 Classification and Applications of Exoskeletons
Thereareseveralclassificationsforexoskeletons.Accordingtotheprincipleof
action, they could be divided into active and passive exoskeletons. Active
devices use an external power source, whereas the mechanics of the passive
exoskeletons relies on kinetic energy and human strength (Pons, 2008).
Exoskeletons can also be classified according to the human limb onto
which the external framework couple to the human body. Thus, exoskel-
etons can be classified in upper-limb (either including or excluding the
hand), lower-limb, and full-body exoskeletons. Upper-limb exoskeletons
enhance the manipulation function, and normally include the shoulder,
elbow, and wrist articulations. A number of investigations devoted to the
application of the exoskeletons for the upper limbs suggest a wide scope
of possible usage. Lower-limb exoskeletons provide support, stability, and
mobility (locomotion).
Applications of exoskeletons include power amplifier, telemanipulation,
rehabilitationandmotor training, virtualreality, andhaptics(Ruiz etal., 2008).

1.2.1 Power Amplifier
The main purpose of a robotic exoskeleton in this application is to amplify
the physical capacities of a human. As a result, the person provides control
signals to the exoskeleton, while the device delivers mechanical power in