Last fall, the Defense Advanced Research Projects Agency (DARPA), the U.S. Army and Rockwell Collins demonstrated Damage Tolerance Control (DTC) on the RQ-7B Shadow Unmanned Aircraft System (UAS), marking the first time that the technology has been tested on a fielded platform. Video of that historic flight test was viewed for the first time during a Rockwell Collins media briefing at AUVSI Unmanned Systems North America 2011.
Flight testing took place over several weeks at Dugway Proving Ground in Utah. The testing verified performance of DTC to determine the limits of damage aircraft can handle, provided the Army with an understanding of DTC’s operational benefits to the Shadow UAS mission and generated awareness of overall progress in adaptive controls technology to encourage continued advancement in operational applications.
“These tests mark an important milestone for DARPA, the Army and Rockwell Collins as we take DTC to the next level of performance on fielded UAS platforms,” said Dave Vos, senior director of Rockwell Collins Control Technologies and Unmanned Aircraft Systems.
“We are now approaching the point where UAVs and manned aircraft can coexist because we can instantly and automatically compensate for failure or damage in flight.” The tests included ejecting 20 inches of the Shadow’s wing during flight. Despite the damage sustained by the Shadow, it remained steady in-flight and landed successfully. These flights also included the first-ever automatic rolling take-off for Shadow, as well as GPS-based automatic landing.
Other maneuvers demonstrating failure and immediate automatic recovery through DTC that were conducted during the flight tests include: Locking the right aileron in neutral position in-line with the rest of the airplane Locking the right aileron in a full-up position, which caused an uncontrolled roll Engine idle test – engine command is idle, which means there is no throttle up or down The right rudder locked at neutral Engine killed during flight to zero RPMs
All these flights ended with the damaged aircraft performing a successful automatic landing.
Damage tolerance is an enabling capability for increasing the mission reliability of UAVs operating in hazardous and high-threat environments. The technology provides for real-time autonomous accommodation of damage, followed by an adaptation process that alters the flight control system to compensate for the effects of the damage. During the flight tests, Rockwell Collins demonstrated a capability that could be applicable to all military aircraft operating in combat environments and to commercial, business and general aviation aircraft for full flight automation and backup.