Robotic Bug Gets Wings, Sheds Light On Evolution of Flight 0

Adding wings to a robotic bug improved running performance and stability. However, the boost may not have been good enough for flight. (Credit: Image by Kevin Peterson, UC Berkeley Biomimetic Millisystems Lab, All rights reserved.)

When engineers at the University of California, Berkeley, outfitted a six-legged robotic bug with wings in an effort to improve its mobility, they unexpectedly shed some light on the evolution of flight.

Even though the wings significantly improved the running performance of the 10-centimeter-long robot -- called DASH, short for Dynamic Autonomous Sprawled Hexapod -- they found that the extra boost would not have generated enough speed to launch the critter from the ground. The wing flapping also enhanced the aerial performance of the robot, consistent with the hypothesis that flight originated in gliding tree-dwellers.
The research team, led by Ron Fearing, professor of electrical engineering and head of the Biomimetic Millisystems Lab at UC Berkeley, reports its conclusions online on Oct. 18, in the peer-reviewed journal Bioinspiration and Biomimetics.
Using robot models could play a useful role in studying the origins of flight, particularly since fossil evidence is so limited, the researchers noted.
First unveiled by Fearing and graduate student Paul Birkmeyer in 2009, DASH is a lightweight, speedy robot made of inexpensive, off-the-shelf materials, including compliant fiber board with legs driven by a battery-powered motor. Its small size makes it a candidate for deployment in areas too cramped or dangerous for humans to enter, such as collapsed buildings.
A robot gets its wings
But compared with its biological inspiration, the cockroach, DASH had certain limitations as to where it could scamper. Remaining stable while going over obstacles is fairly tricky for small robots, so the researchers affixed DASH with lateral and tail wings borrowed from a store-bought toy to see if that would help.
"Our overall goal is to give our robots the same all-terrain capabilities that other animals have," said Fearing. "In the real world, there will be situations where flying is a better option than crawling, and other places where flying won't work, such as in confined or crowded spaces. We needed a hybrid running-and-flying robot."
The researchers ran tests on four different configurations of the robotic roach, now called DASH+Wings. The test robots included one with a tail only and another that just had the wing's frames, to determine how the wings impacted locomotion.
With its motorized flapping wings, DASH+Wings' running speed nearly doubled, going from from 0.68 meters per second with legs alone to 1.29 meters per second. The robot could also take on steeper hills, going from an incline angle of 5.6 degrees to 16.9 degrees.
"With wings, we saw improvements in performance almost immediately," said study lead author Kevin Peterson, a Ph.D. student in Fearing's lab. "Not only did the wings make the robot faster and better at steeper inclines, it could now keep itself upright when descending. The wingless version of DASH could survive falls from eight stories tall, but it would sometimes land upside down, and where it landed was partly guided by luck."
The flapping wings improved the lift-drag ratio, helping DASH+Wings land on its feet instead of just plummeting uncontrolled. Once it hit the ground, the robot was able to continue on its way. Wind tunnel experiments showed that it is aerodynamically capable of gliding at an angle up to 24.7 degrees.
Tree-dwellers vs. ground-runners
The engineering team's work caught the attention of animal flight expert Robert Dudley, a UC Berkeley professor of integrative biology, who noted that the most dominant theories on flight evolution have been primarily derived from scant fossil records and theoretical modeling.
He referenced previous computer models suggesting that ground-dwellers, given the right conditions, would need only to triple their running speed in order to build up enough thrust for takeoff. The fact that DASH+Wings could maximally muster a doubling of its running speed suggests that wings do not provide enough of a boost to launch an animal from the ground. This finding is consistent with the theory that flight arose from animals that glided downwards from some height.
"The fossil evidence we do have suggests that the precursors to early birds had long feathers on all four limbs, and a long tail similarly endowed with a lot of feathers, which would mechanically be more beneficial for tree-dwelling gliders than for runners on the ground," said Dudley.
Dudley said that the winged version of DASH is not a perfect model for proto-birds -- it has six legs instead of two, and its wings use a sheet of plastic rather than feathers -- and thus cannot provide a slam-dunk answer to the question of how flight evolved.
"What the experiments did do was to demonstrate the feasibility of using robot models to test hypotheses of flight origins," he said. "It's the proof of concept that we can actually learn something useful about biological performance through systematic testing of a physical model."
Among other robotic insects being tested in the Biomimetic Millisystems Lab is a winged, bipedal robot called BOLT (Bipedal Ornithopter for Locomotion Transitioning) that more closely resembles the size and aerodynamics of precursors to flying birds and insects.
"It's still notable that adding wings to DASH resulted in marked improvements in its ability to get around," said Fearing. "It shows that flapping wings may provide some advantages evolutionarily, even if it doesn't enable flight."
The National Science Foundation's Center of Integrated Nanomechanical Systems and the U.S. Army Research Laboratory helped support this research.
(University of California - Berkeley)

Robot Builds Itself With Foam 0

Foambot (Image: Modular Robotics Laboratory)

Combine off-the-shelf insulation foam and modular robot components and you get a self-assembling robot that could be fit to a variety of tasks.
The Modular Robotics Laboratory at the University of Pennsylvania, in a project led by Shai Revzen, has created a robot that can be assembled from foam that hardens and pieces that allow the robot to move. The “foambot” looks ungainly, and it is. But once you have a shape -- and a task -- in mind, the foam sprayer can lay down a body plan that fits.
For example, lining up a bunch of the actuators (the modular robot parts) can create a snake-like bot that can move into small, narrow spaces, while arranging them in another pattern allows for a more conventional four-legged arrangement.
A key advantage of this kind of construction is that you don’t need to know what your robot has to do beforehand. Robots today are, for the most part, designed with very specific tasks in mind. Think of a Roomba –- it is designed solely to vacuum floors. But if one is sending a robot someplace where it isn’t clear what you need, then it helps to be able to decide on the task and build on the spot.
The robot’s parts are CKBot modules, which can be taken apart and reassemble themselves, because the components can recognize where they are in relation to each other. The foam is commercially available insulation, and it turns out such foams are a great material. Revzen noted in an email that they expand to 30 times their initial size, and are actually quite strong. That means that the apparatus building a robot can be smaller than what it is building.
This has applications in areas such as space exploration, where building a robot that can crawl, slither or climb allows for exploring an unknown landscape, or rescue operations, where the situation is unknown and it isn’t clear what you need a robot to do (crawl through small spaces or clamber over rubble, or both).

Bug-Like Robotic Drones 0

Big Eyes, Tiny Hairs (credit: JJ Harrison via Wikimedia)

Micro air vehicles, or MAVs, make for a tantalizing option for intelligence and surveillance agencies looking to surreptitiously gather information or deliver surveillance devices without being seen. But MAVs--usually modeled after small birds or insects-- are notoriously unstable in flight and difficult to maneuver in cluttered environments. So the Pentagon is handing out research contracts to make the DoD’s little robotic bugs more stable by making them more bug-like. Specifically, the DoD wants big bulging bug eyes and hairy wings for its MAVs.
The main problem with MAVs has to do with the way they respond (or don’t respond) to dynamic environments--things like shifting or gusting winds, moving bodies, and other variables that have to be accounted for in realtime. MAVs are tiny, so there’s not a lot of space for computing assets or sensor payloads, and that leads to a sort of intractable problem: how can engineers make these things smaller and more capable while also adding increased situational awareness and better in-flight processing?
When facing a tough problem like this a little biomimicry never hurts, and that’s exactly where the Pentagon is looking with its recent contracts. If two research stipends recently handed down are any indication, the micro-drones of the future may have tiny hair-like sensors all over their bodies and big, compound eyes.
The cilia-like hairs will serve to keep the drones’ hovering and flight stable by sensing changes in air flow at the tiniest levels. That means the drone could sense a wind gust coming shortly before it arrives, allowing it to compensate for the change in circumstance. It would also aid in maintaining overall stability during flight, as the MAVs central processor would possess a constant awareness of--and the ability to manipulate--the boundary flow layer of air surrounding the drone as it hovers and flies.
The bug-like compound eyes would similarly help MAVs navigate in cluttered spaces by increasing the amount of visual data available to the drones’ processors. An on-board minicomputer would process images in realtime, using those visual cues to automatically avoid obstacles and navigate cleanly and efficiently.
[Danger Room]

At Last, The First Humanoid Robot Astronaut Powers Up Aboard the ISS 0

This Space Station's Not Big Enough for the Two of Us NASA

Our favorite Twitter ‘bot--no, like an actual robot that tweets--is out of the box and live-tweeting its new life on the International Space Station. Robonaut 2 was actually unboxed several months ago (it was delivered by the final Discovery mission in February) but has been sitting idly, waiting for the crew to get around to firing it up. Now R2 is plugged in, and man is it ever chatty.
“Those electrons feel GOOD!,” R2 tweeted yesterday as its visual systems were powered on. “One small step for man, one giant leap for tinman kind.”
Har har. But humanoid humor aside, this is a big step for those who have been following R2’s progress from the labs at NASA to his launch aboard Discovery to his arrival at the ISS (R2 has been tweeting all of this along the way). It is the first humanoid robot ever taken into space, and he very well could be the model for many future generations of humanoid helper ‘bots launched aboard orbiting spacecraft and perhaps even on a future deep space mission. Along the way, future versions of R2 may even assist ISS astronauts during spacewalks.
Right now, R2 is only a waist-up humanoid; his torso is anchored to a pedestal from which he can use his arms to help human crew members in the orbiting lab. But a pair of legs is being designed for R2 and could launch to the ISS in 2013, at which point it will become something of a real life C-3PO capable of following around its human counterparts, getting into all kinds of scrapes, and providing somewhat flat comic relief.

[io9]