System Bits: June 27

Quantum coding; driving drones; safer autonomous vehicles.


Entangling photons for bug-proof communication
With the increasing processing power of computers, conventional encryption of data is becoming increasingly insecure, reminded Fraunhofer researchers that are proposing one solution is coding with entangled photons. The team is developing a quantum coding source that allows the transport of entangled photons from satellites, expected to be an important step in the direction of tap-proof communication.

Fraunhofer IOF‘s quantum source. Designed to be fully operational even after extreme stress. (Source: Fraunhofer IOF)

Data is currently encrypted mostly based on mathematical methods —no matter if it is information resulting from the communication between two banks, government organizations or private individuals. The problem comes in with the increasing processing power of computers that makes the decoding of encrypted messages progressively easier. Further, developments such as quantum computers could eliminate current encryption methods, since much more effective decryption algorithms can be used in this regard than is possible with conventional computers, the researchers explained.

They noted that encryption by means of a physical principle, the so-called quantum entanglement offers a solution: first, twin-photons are generated which are entangled with each other regarding certain quantum states and which are therefore dependent upon each other. What this means is that if the polarization of the one photon is measured, for example, then that of the twin is also known automatically. This effect is special because it works independently of the distance between the photons.

Then, based on this concept, codes can be generated that allow the sender and receiver to see at a glance whether third parties have attempted to manipulate or tap the codes.

Dr. Erik Beckert of the Fraunhofer Institute for Applied Optics and Precision Engineering IOF in Jena, Germany said, “The central element here is the quantum source in which the photons are entangled. The entangled photons are generated in a sophisticated laser-optic assembly and then directed via different channels to the two parties that want to protect their communication from listeners.”

This begs the questions as to how the entangled photons reach their destination. If they are sent through the air or glass fiber via an open jet line, the range is limited, since the turbulence of the atmosphere or the damping of the glass fiber interferes with the entanglement. The Fraunhofer researchers instead propose that the quantum source distribute the entangled photons from a satellite, which results in the photons only having to travel a relatively short distance through the atmosphere until they reach their receiver. But to place a quantum source on a satellite it must be extremely stable in order to withstand both the impacts of a rocket launch as well as the special conditions in space, such as strong temperature fluctuations and radiation.

To this end, the team is developing a quantum source which is so stable that the precise calibration and the difficult adjustments are not disturbed even by the extreme stress of a rocket launch or the inhospitable conditions in space.

Flying, driving quadcopters
Researchers from MIT’s Computer Science and Artificial Intelligence Laboratory (CSAIL) propose that if robots could be programmed to both walk and take flight, it would open up possibilities including machines that could fly into construction areas or disaster zones that aren’t near roads, and squeeze through tight spaces on the ground to transport objects or rescue people. However, the team said the problem is that robots that are good at one mode of transportation are usually bad at another: Airborne drones are fast and agile, but generally have too limited of a battery life to travel for long distances. Ground vehicles, on the other hand, are more energy efficient, but slower and less mobile.

To this end, the researchers are aiming to develop robots that can both maneuver around on land and take to the skies. In a new paper, the team presented a system of eight quadcopter drones that can fly and drive through a city-like setting with parking spots, no-fly zones, and landing pads.

One of the researchers’ quadcopter drones with wheels.
(Source: Brandon Araki/MIT CSAIL)

PhD student Brandon Araki, lead author on the paper said, “The ability to both fly and drive is useful in environments with a lot of barriers, since you can fly over ground obstacles and drive under overhead obstacles. Normal drones can’t maneuver on the ground at all. A drone with wheels is much more mobile while having only a slight reduction in flying time.”

Araki and CSAIL Director Daniela Rus developed the system, along with MIT undergraduate students John Strang, Sarah Pohorecky, and Celine Qiu, and Tobias Naegeli of ETH Zurich’s Advanced Interactive Technologies Lab. The team presented their system at IEEE’s International Conference on Robotics and Automation (ICRA) in Singapore earlier this month.

Connected technology for safer self-driving cars demonstrated
Helping to move autonomous driving technology closer to real-world use, the University of Michigan’s Mcity Test Facility conducted a series of demonstrations that illustrated the key role connected technology can play in harnessing the safety benefits that self-driving vehicles promise.

In one demonstration, a car barrels through a red light, but a Lincoln MKZ leading the cross traffic doesn’t T-bone it. In fact, the Lincoln never enters the intersection. It gradually slows down and yields to the law-breaking vehicle with time to spare.

In another demonstration, a car is stopped dead in the road around a blind curve, but a Kia Soul that comes up behind it doesn’t rear-end it. The Kia doesn’t even brake hard. It gently comes to a stop before its passengers even register the obstacle.

The Lincoln and the Kia are connected and automated research vehicles—self-driving cars that can make decisions about how to behave based on communication with other vehicles and the infrastructure around them, the researchers said.

“Connectivity and automation together offer the greatest potential to make vehicles safer, as well as reduce fuel use and increase access to transportation to those with few or no options today,” according to Carrie Morton, deputy director of Mcity, a U-M-led public-private partnership working to advance next-generation mobility.

In a typical driverless vehicle prototype, cameras, lidar and radar devices serve as eyes, but these sensors can’t detect obstacles beyond their line of sight—like the stopped car behind the blind curve, for example. Connected technology changes that, the researchers asserted.

Through vehicle-to-vehicle communication, or V2V, cars can wirelessly and securely share data about their location, direction and speed at the rate of 10 messages per second, using Dedicated Short Range Communications (DSRC). V2V communications allow the vehicle to see where other sensors cannot, thereby increasing the safety of all vehicles.