Biomedical Engineering Reference
In-Depth Information
Figure 6.7
Contemporary bipedal robots: (a) Wow Wee's RoboSapien, (b) Sony's Qrio
Q
2003, and (c) AIST's
HRP-2P.
bipeds do not receive the shock absorption, ''preflex'' stabilizing advantages, or inverse-pendulum
energy-recycling advantages of mechanically compliant animal locomotion systems.
At least one humanlike biped does take advantage of mechanical compliance: the low cost Wow
Wee ''RoboSapien'' biped (Figure 6.7a) engineered by physicist Mark Tilden. As a result of this,
Robosapien is more energy efficient than other biped humanoids, running for several hours on a
charge (versus Sony's and Honda's bipeds, which run for ~30 min on a charge).
Of the publicly-shown biped robots, the 18 in. tall Sony Qrio (Figure 6.7b) shows the greatest
range of biped functionality and cognitive abilities. As a biped, the robot cannot just walk, but run,
hop, and right itself from a fall. Its movements are extremely swift, graceful, and humanlike, and its
grasping hands enable Qrio to toss a ball.
Of human-scale bipeds, the HRP-2P of Kawada, Japan is remarkable for its ability to climb to its
feet from a lying posture (Figure 6.7c).
The rate of progress in the ability of legged robots and bipeds, in particular, is extremely
encouraging. It is easy to imagine that such devices will be commonplace in entertainment and
service applications in coming years.
6.2.4
Flying, etc.
Many biomimetic or bio-inspired flying robots have shown swift progress of late. Many of these
imitate the small scale flight of insects, while others fly at larger scales, after the fashion of birds.
The Micromechanical Flying Insect (MFI) Project at University of California, Berkeley has
demonstrated a 30-mm MFI prototype (see Figure 6.8), using piezoelectric actuators and a flexible
thorax structure to incur notable thrust force (Dickinson, 2001) and demonstrate flight (MFI
Website, 2002). This performance results from extensive studies of the aerodynamics of fly-wings
in motion, which explain how flies generate three times as much lift as was previously understood
(Dickinson, 2001). This work demonstrates that insect flight results from three phenomena: the
leading-edge vortex (or delayed stall), the rotational lift, and the wake capture. Funded by DARPA,
ONR, and MURI, the ultimate goal of the MFI project is to produce autonomous military robots.
The Mentor robot (1998 to 2002) of SRI International and University of Toronto was the first
flapping wing microaviation vehicle (MAV) capable of hovering in place. Weighing 435 g, and 30
cm in height, the double-hummingbird X-wing model flew in a tethered mode, demonstrating both
hovering and forward flight (DeLaurier, 2003). University of Toronto designed and built the
complete aircraft system and SRI investigated actuating the device with dielectric-type electro-
active polymers (EAP) artificial muscles.
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