Snake-inspired robot slithers even better than predecessor 04-19

 Bad news for ophiophobes: Researchers from the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) have developed a new and improved snake-inspired soft robot that is faster and more precise than its predecessor.

 The robot is made using kirigami — a Japanese paper craft that relies on cuts to change the properties of a material.  As the robot stretches, the kirigami surface “pops up” into a 3D-textured surface, which grips the ground just like snake skin.

The first-generation robot used a flat kirigami sheet, which transformed uniformly when stretched. The new robot has a programmable shell, meaning the kirigami cuts can pop up as desired, improving the robot’s speed and accuracy.

The research was published in the Proceedings of the National Academy of Sciences.

“This is a first example of a kirigami structure with non-uniform pop-up deformations,” said Ahmad Rafsanjani, a postdoctoral fellow at SEAS and first author of the paper. “In flat kirigami, the pop-up is continuous, meaning everything pops at once.  But in the kirigami shell, pop up is discontinuous. This kind of control of the shape-transformation could be used to design responsive surfaces and smart skins with on-demand changes in their texture and morphology.”

The new research combined two properties of the material — the size of the cuts and the curvature of the sheet. By controlling these features, the researchers were able to program dynamic propagation of pop ups from one end to another, or  control localized pop-ups.

In previous research, a flat kirigami sheet was wrapped around an elastomer actuator. In this research, the kirigami surface is rolled into a cylinder, with an actuator applying force at two ends. If the cuts are a consistent size, the deformation propagates from one end of the cylinder to the other. However, if the size of the cuts are chosen carefully, the skin can be programmed to deform at desired sequences.  

“By borrowing ideas from phase-transforming materials and applying them to kirigami-inspired architected materials, we demonstrated that both popped and unpopped phases can coexists at the same time on the cylinder,” said Katia Bertoldi, the William and Ami Kuan Danoff Professor of Applied Mechanics at SEAS and senior author of the paper. “By simply combining cuts and curvature, we can program remarkably different behavior.”

Next, the researchers aim to develop an inverse design model for more complex deformations.

“The idea is, if you know how you’d like the skin to transform, you can just cut, roll and go,” said Lishuai Jin, a graduate student at SEAS and coauthor of the article.

China’s state-run press agency has created an ‘AI anchor’ to read the news. 11-12

Xinhua, China’s state-run press agency, has unveiled new “AI anchors” — digital composites created from footage of human hosts that read the news using synthesized voices.

It’s not clear exactly what technology has been used to create the anchors, but they’re in line with the most recent machine learning research. It seems that Xinhua has used footage of human anchors as a base layer, and then animated parts of the mouth and face to turn the speaker into a virtual puppet. By combining this with a synthesized voice, Xinhua can program the digital anchors to read the news, far quicker than using traditional CGI. (We’ve reached out to AI experts in the field to see what their analysis is.)

According to reports from Xinhua and the South China Morning Post, two anchors (one for English broadcasts and one for Chinese) were created in collaboration with local search engine company Sogou. Xinhua says the anchors have “endless prospects” and can be used to cheaply generate news reports for the agency’s TV, web, and mobile output.

Each anchor can “work 24 hours a day on its official website and various social media platforms, reducing news production costs and improving efficiency,” says Xinhua.

The technology has its limitations. In the videos above and below of the English-speaking anchor, it’s obvious that the range of facial expressions are limited, and the voice is clearly artificial. But machine learning research in this area is making swift improvements, and it’s not hard to imagine a future where AI anchors are indistinguishable from the real thing. 

This will strike many as a disturbing prospect, especially as the technology is being deployed in China. There, the press is constantly censored, and it is nearly impossible to get clear reports of even widespread events like the country’s suppression of the Muslim Uighur community. Creating fake anchors to read propaganda sounds chilling.

But what the actual effect on society may be if such anchors become widespread is hard to judge. If Xinhua wants someone to read the news without questioning it they don’t need AI to make that happen. Meanwhile, synthetic characters are slowly finding their way into mainstream culture, with figures like virtual pop star Hatsune Miku and CGI Instagram models familiarizing the public with this sort of creation.

But while these examples fall clearly into the world of entertainment, having AI anchors read the news suggests the technology could become more than a novelty. 

ments

A close up of the Xinhua AI anchor’s face. Only the mouth looks edited.

'Hedgehog' Robots Hop, Tumble in Microgravity 09-06

'Hedgehog'  Robots  Hop,  Tumble  in  Microgravity

While a Mars rover can't operate upside down, the Hedgehog robot can function regardless of which side lands up. Credit: NASA/JPL-Caltech/Stanford

Hopping, tumbling and flipping over are not typical maneuvers you would expect from a spacecraft exploring other worlds. Traditional Mars rovers, for example, roll around on wheels, and they can't operate upside-down. But on a small body, such as an asteroid or a comet, the low-gravity conditions and rough surfaces make traditional driving all the more hazardous.

Enter Hedgehog: a new concept for a robot that is specifically designed to overcome the challenges of traversing small bodies. The project is being jointly developed by researchers at NASA's Jet Propulsion Laboratory in Pasadena, California; Stanford University in Stanford, California; and the Massachusetts Institute of Technology in Cambridge.

"Hedgehog is a different kind of robot that would hop and tumble on the surface instead of rolling on wheels. It is shaped like a cube and can operate no matter which side it lands on," said Issa Nesnas, leader of the JPL team.

The basic concept is a cube with spikes that moves by spinning and braking internal flywheels. The spikes protect the robot's body from the terrain and act as feet while hopping and tumbling.

"The spikes could also house instruments such as thermal probes to take the temperature of the surface as the robot tumbles," Nesnas said.

Two Hedgehog prototypes -- one from Stanford and one from JPL -- were tested aboard NASA's C-9 aircraft for microgravity research in June 2015. During 180 parabolas, over the course of four flights, these robots demonstrated several types of maneuvers that would be useful for getting around on small bodies with reduced gravity. Researchers tested these maneuvers on different materials that mimic a wide range of surfaces: sandy, rough and rocky, slippery and icy, and soft and crumbly.

"We demonstrated for the first time our Hedgehog prototypes performing controlled hopping and tumbling in comet-like environments," said Robert Reid, lead engineer on the project at JPL.

Hedgehog's simplest maneuver is a "yaw," or a turn in place. After pointing itself in the right direction, Hedgehog can either hop long distances using one or two spikes or tumble short distances by rotating from one face to another. Hedgehog typically takes large hops toward a target of interest, followed by smaller tumbles as it gets closer.

During one of the experiments on the parabolic flights, the researchers confirmed that Hedgehog can also perform a "tornado" maneuver, in which the robot aggressively spins to launch itself from the surface. This maneuver could be used to escape from a sandy sinkhole or other situations in which the robot would otherwise be stuck.

The JPL Hedgehog prototype has eight spikes and three flywheels. It weighs about 11 pounds (5 kilograms) by itself, but the researchers envision that it could weigh more than 20 pounds (9 kilograms) with instruments such as cameras and spectrometers. The Stanford prototype is slightly smaller and lighter, and it has shorter spikes.

Both prototypes maneuver by spinning and stopping three internal flywheels using motors and brakes. The braking mechanisms differ between the two prototypes. JPL's version uses disc brakes, and Stanford's prototype uses friction belts to stop the flywheels abruptly.

"By controlling how you brake the flywheels, you can adjust Hedgehog's hopping angle. The idea was to test the two braking systems and understand their advantages and disadvantages," said Marco Pavone, leader of the Stanford team, who originally proposed Hedgehog with Nesnas in 2011.

"The geometry of the Hedgehog spikes has a great influence on its hopping trajectory. We have experimented with several spike configurations and found that a cube shape provides the best hopping performance. The cube structure is also easier to manufacture and package within a spacecraft," said Benjamin Hockman, lead engineer on the project at Stanford.

The researchers are currently working on Hedgehog's autonomy, trying to increase how much the robots can do by themselves without instructions from Earth. Their idea is that an orbiting mothership would relay signals to and from the robot, similar to how NASA's Mars rovers Curiosity and Opportunity communicate via satellites orbiting Mars. The mothership would also help the robots navigate and determine their positions.

The construction of a Hedgehog robot is relatively low-cost compared to a traditional rover, and several could be packaged together for flight, the researchers say. The mothership could release many robots at once or in stages, letting them spread out to make discoveries on a world never traversed before.

Hedgehog is currently in Phase II development through the NASA Innovative Advanced Concepts (NIAC) Program, and is led by Pavone. The flight development and testing were supported by NASA's Center Innovation Fund (CIF) and NASA's Flight Opportunities Program (FOP), which were led by Nesnas. NIAC, CIF and FOP are programs in NASA's Space Technology Mission Directorate, located at the agency's headquarters in Washington. JPL is managed by the California Institute of Technology for NASA. Stanford University, MIT and JPL collaborate on the project.

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