The controls team recently completed a successful test of an autonomous crosswind flight – checking off another major research and development milestone for the Joby Energy airborne wind turbine.
The controls team tested a 7 ft. (2.5 meter) wingspan prototype with a tail at its local test site near Davenport, CA on September 23, 2010.
“We went into overdrive to achieve our goal and accomplished it,” said Joby Energy engineer, Greg Horn. “We proved autonomous flight on a tether with full computer control for more than seven minutes.”
According to Horn, developing reliable and robust autonomous controls is a main engineering challenge to technology development.
“Mastering autonomous controls is essential to the development of airborne wind turbines,” he said. “It’s important to have robotic pilots fly systems when we launch multiple commercial systems for economic, safety and reliability reasons.”
The controls team is working steadily to progress on smaller vehicles.
“Using small prototypes, we can make rapid advances to gain technology leadership,” he said. “The next incremental step is to get the vehicle to achieve autonomous flight with a canard or without a tail.
In addition to Horn, the controls team is comprised of: Mike Sherback, Ph.D. Frederick Bourgault, Ph.D., Henry Hallam, Piotr Esden-Tempski, Allen Ibara, and Fergus Noble.
The next major milestone for the controls team is to successfully demonstrate longer-duration autonomous crosswind flight for 24 hours.
Controls Engineer Michael Sherback, Ph.D., noted that in addition to the successful autonomous controls test, the team made significant progress with unconventional VTOL aircraft.
“Our Mercury 9 prototype completed testing of the feedback loops required to fly it on the tether: angle of attack, sideslip angle, and roll,” he said. “The flight software was also reconfigured to allow it to be tested in simulation which contributed to attaining the autonomous milestone.”
Sherback said that the Mercury 9 prototype vehicle has since taken up a quiet and intact retirement and its successor will soon be available for tethered flight-testing.
Construction of the next generation Joby Energy prototype vehicle is underway at the Windward Performance facility in Bend, OR. Windward Performance is a designer and manufacturer of high performance gliders and aircraft.
Composites team members Jessie Chebot and Ben Bancroft recently decamped for a three-week composites residency program.
Carter, Joby Energy’s chief composites technician, said the experience is designed to improve the skill sets of the team members and to advance prototype build processes.
“It’s a great learning opportunity for Jessie and Ben,” Carter said. “We’re all excited and look forward to an exchange of knowledge and learning new techniques.”
Windward Performance owner Greg Cole will collaborate on the build, and offer his workshop and expertise to accommodate the building and assembly of the next generation 20 kW prototype vehicle.