Jack W. Langelaan, Ph.D.
Associate Professor of Aerospace Engineering
229 Hammond Building
Penn State University
University Park, PA 16802
Phone: 814-863-6817 / Fax: 814-865-7092
E-mail: jlangelaan@psu.edu
An eagle can soar for many miles and many hours without ever flapping its wings. Jack Langelaan, a Penn State assistant professor of aerospace engineering, wants to build a small robotic glider that can do the same thing on its own – no pilot, no motor, no remote control. In fact, he can foresee a time when flocks of these little gliders flying about 500 feet off the ground collect data about wind gust fields and other atmospheric goings-on that are valuable to meteorologists and other scientists, as well as to the military.
The data they collect will also be valuable to designers of future robotic gliders. As Langelaan sees it, the trick to keeping these small autonomous vehicles aloft lies in understanding the interaction between micro-gusts and things that fly, be they human-made vehicles or nature-made birds. Ultimately, the gliders’ success will depend on how appropriately and readily their computers and control systems can mimic the birds – making tiny adjustments to the control surface configurations of their wings and tail so they can bounce along on the air. “There is a lot of energy in the atmosphere,” Langelaan says. “We want to figure out how to exploit it.”
As of Spring 2009, Langelaan had four autonomous vehicles under construction in his lab in 210 Unit C, behind the Hammond Engineering Building on the Penn State University Park campus. The largest has a wingspan of 14 feet and weighs about 20 pounds, while the smallest has a wingspan of 4 feet and weighs about 2 pounds. All of the aircraft can be hand-launched, which makes operating them simple. Beginning with off-the-shelf radio-control airplanes, graduate students then equip the craft with a GPS receiver to compute position and speed with respect to the Earth; sensors to measure air speed, acceleration, rotation rate, and the Earth’s magnetic field; and microprocessors to collect and process the data and to direct the function of the control surfaces. The sensors and microprocessors are powered using a high-end, off-the-shelf lithium polymer battery. Maiden flights were set for Summer 2009.
To tell the robotic gliders how to fly, Langelaan and his team have devised planning and control algorithms based on data collected by big planes flying at high altitudes. Just how closely that data reflects the realities at lower altitudes, Langelaan won’t know until gliders collect data of their own.
In fact, there has never been a good way to gather the low-altitude information Langelaan envisions his flocks of gliders amassing. The only means of doing so now are sensors mounted on balloons or poles, both of which provide only limited data. Pole-mounted sensors do not move, and thus collect data only at a single point; balloon-borne sensors drift where the wind carries them. A small aircraft can fly where the scientist wants it to go, gathering data at multiple points. Even better, a flock of them could do this while moving in a coordinated way over terrain. Among the benefits of this information could be new insights into how tornados and thunderstorms arise, how particulate matter and other pollution is dispersed, and how air behaves over a forest in contrast to how it behaves over bare land.
Langelaan would like to say he was lying in a meadow pondering the sky when an eagle flew over, giving him the idea for the project. But the facts are more prosaic. A conference was coming up, and he needed an idea for a paper. At the same time, though, he was inspired by Penn State’s proximity to the Allegheny-Bald Eagle Ridge, a mecca for soaring, which also makes it a natural place to embark on a glider-based project. The research also suited Langelaan’s own background. His dad, an architect by profession, flew gliders in his spare time. Langelaan says he pretty much grew up at the glider field, earning his own license to soar at 16.
Professor Langelaan was born in Holland and moved with his family to Canada when he was three years old. Growing up in Calgary, Alberta, and in the suburbs of Toronto, Ontario, he was interested in model rocketry. He attended Queen’s University in Kingston, Ontario, where he earned his bachelor of science degree in Engineering Physics, then went on to earn a master’s degree at the University of Washington, and his doctorate in the Department of Aeronautics and Astronautics at Stanford University. He joined the Penn State faculty in 2006 and in 2008 was awarded a prestigious National Science Foundation Early Career Development grant to fund his glider project. The title of the proposal was "Theory and Practice of Autonomous Soaring for Aerial Robots."
Langelaan teaches upper division classes on aerospace controls and flight dynamics and graduate classes on global positioning systems and estimation, a way of using mathematics to combine noisy, uncertain measurements with predictions, yielding best guesses that can be used for making computer models of things like the interaction between micro-gusts and autonomous aerial vehicles. He lives a bike-able three miles from the Penn State campus with his wife and three children, the oldest one in elementary school. None of the children has yet identified a career interest in aerospace, but when they hear a plane overhead, they all look up and wait for Dad to identify it.