Research by Rensselaer Polytechnic Institute Professor Carlos Varela Develops “Active Data” System
Thirty lines of computer code might have saved Air France flight 447, and 228 passengers and crew aboard, from plunging into the Atlantic Ocean on June 1, 2009, according to new research by Carlos Varela, an associate professor of computer science at Rensselaer Polytechnic Institute. Varela and his research group have developed a computer system that detects and corrects faulty airspeed readings, such as those that contributed to the AF447 crash. Their approach to detecting errors could be applicable in many systems that rely on sensor readings.
GNU Free Documentation License Copyright © 2007 David Monniaux
Pitot tube from an Airbus A380.
“During this flight, important sensors failed, and reported erroneous data. But the autopilot didn’t know that, and it acted as if the data were correct,” said Varela. “We have computers that can beat the best human Jeopardy! players, and yet we rely on these relatively weak autopilot systems to safeguard hundreds of people on each flight. Why don’t we add more intelligence to autopilot systems?”
Varela’s research, aimed at developing “active data,” was funded by the Air Force Office of Scientific Research under the Dynamic Data Driven Application Systems (DDDAS) program. The goal of the grant is to develop mathematical and programming elements that enable otherwise passive data systems to search for patterns and relationships, and discover knowledge in data streams. Varela, who is himself a pilot, recognized that robust “active data” systems could have prevented the crash of flight AF447. Shigeru Imai, a computer science graduate student, originally presented their research and results at the 2nd International Conference Big Data Science and Engineering in December 2013.
AF447 crashed into the Atlantic Ocean more than 400 miles off Brazil’s northeastern coast. When recovered, the “black box” flight recorders revealed a chain of events beginning with erroneous readings from the pitot tubes – instruments that use air pressure to calculate airspeed. The pitot tubes, presumably blocked by ice, reported a drop in airspeed from 461 to 182 knots. The autopilot, unaware of the error, lowered the nose of the airplane in an attempt to increase airspeed. Unable to maintain altitude, the autopilot disengaged, at which point three human pilots were not able to correct for the error.
Varela and his research group focused on failure of the airspeed sensors. In the event of a pitot tube failure, airspeed can be accurately calculated using groundspeed and wind speed data gathered from onboard instruments that monitor GPS satellites, and weather forecasting information obtained prior to the flight. The relationship between the three data streams provided the group with an opportunity.
“If we can capture the mathematical relationship between the data streams, we can look at the patterns that arise upon known failures, which we call ‘error signatures,’” Varela said. “Then we can say ‘oh, this anomaly in the data corresponds to a known hardware failure. We know what is happening.’”
The group created a programming language called the “ProgrammIng Language for spatiO-Temporal data Streaming applications,” or “PILOTS,” and used it to write a program that examines the three data streams and searches for an error signature. If a signature is detected, the system corrects the error using data from the other two streams. In test runs, the PILOTS program – which uses about 30 lines of high-level code to govern a constant analysis of the data – prevented the AF 447 crash.
“We put the data from the black box of this Air France flight in our model, and in five seconds we were able to detect that the pitot tubes had iced, and we were able to compute the correct airspeed,” said Varela. “During the actual flight, the pitot tubes were only iced for 40 seconds, but by the time they were functioning properly again, the plane was descending at about 10,000 feet per minute.”
Varela said the approach has many other applications. In the context of autopilot systems, Varela said active data could potentially prevent errors like those behind the 2005 crash of Tuninter Flight 1153, in which pilots trusted a faulty fuel indicator, and could aid pilots in situations like the 2009 controlled ditch of US Airways Flight 1549 into the Hudson River.
Varela said the concept could also be helpful in other applications that rely on sensors, such as healthcare, where sensors used to collect data from patients could detect early signs of seizures or heart attacks based on patterns in the data.
Mary Martialay | newswise
New technique controls autonomous vehicles on a dirt track
24.05.2016 | Georgia Institute of Technology
Engineers take first step toward flexible, wearable, tricorder-like device
24.05.2016 | University of California - San Diego
A biological and energy-efficient process, developed and patented by the University of Innsbruck, converts nitrogen compounds in wastewater treatment facilities into harmless atmospheric nitrogen gas. This innovative technology is now being refined and marketed jointly with the United States’ DC Water and Sewer Authority (DC Water). The largest DEMON®-system in a wastewater treatment plant is currently being built in Washington, DC.
The DEMON®-system was developed and patented by the University of Innsbruck 11 years ago. Today this successful technology has been implemented in about 70...
Permanent magnets are very important for technologies of the future like electromobility and renewable energy, and rare earth elements (REE) are necessary for their manufacture. The Fraunhofer Institute for Mechanics of Materials IWM in Freiburg, Germany, has now succeeded in identifying promising approaches and materials for new permanent magnets through use of an in-house simulation process based on high-throughput screening (HTS). The team was able to improve magnetic properties this way and at the same time replaced REE with elements that are less expensive and readily available. The results were published in the online technical journal “Scientific Reports”.
The starting point for IWM researchers Wolfgang Körner, Georg Krugel, and Christian Elsässer was a neodymium-iron-nitrogen compound based on a type of...
In the Beyond EUV project, the Fraunhofer Institutes for Laser Technology ILT in Aachen and for Applied Optics and Precision Engineering IOF in Jena are developing key technologies for the manufacture of a new generation of microchips using EUV radiation at a wavelength of 6.7 nm. The resulting structures are barely thicker than single atoms, and they make it possible to produce extremely integrated circuits for such items as wearables or mind-controlled prosthetic limbs.
In 1965 Gordon Moore formulated the law that came to be named after him, which states that the complexity of integrated circuits doubles every one to two...
Characterization of high-quality material reveals important details relevant to next generation nanoelectronic devices
Quantum mechanics is the field of physics governing the behavior of things on atomic scales, where things work very differently from our everyday world.
When current comes in discrete packages: Viennese scientists unravel the quantum properties of the carbon material graphene
In 2010 the Nobel Prize in physics was awarded for the discovery of the exceptional material graphene, which consists of a single layer of carbon atoms...
24.05.2016 | Event News
20.05.2016 | Event News
19.05.2016 | Event News
27.05.2016 | Awards Funding
27.05.2016 | Life Sciences
27.05.2016 | Life Sciences