July 23, 2012
Despite unforeseen flying challenges beyond their control, the UT Austin Unmanned Aerial Vehicle (UAV) team still managed to receive 3rd place in the journal paper award at the 2012 Association for Unmanned Aerial Vehicle Systems International (AUVSI) Student Unmanned Aircraft Systems (UAS) Competition, which took place in Lexington Park, Maryland this past June. This was the fourth year that the team participated in the competition.
UAV team lead Ben Harrison said the paper received such a high score because it followed a logical progression from mission requirements to the resulting subsystem design, testing and risk assessment. Team members read the rules thoroughly and ensured that the journal paper discussed topics that were most important to the judges. Their hard work paid off with a $2,000 cash prize and a plaque, which is now proudly displayed in the UT Air Systems Design Laboratory.
For team members who had been working on designing and refining the Phoenix II aircraft and the accompanying system over the past year, flying in the competition was what they had been looking forward to most. Members of the team spanned across a discipline of majors, including computer sciences, electrical engineering and aerospace engineering. Students who attended the competition, all aerospace majors, included Ben Harrison, Wiley Mosely, Jason Kish and Will Chaney.
The UT UAV team had the unique advantage of being only one of three other teams that designed and built their own airplanes in-house. A total of 26 teams entered the competition.
“There were only three other teams that built their own aircraft,” said Harrison. “Design and construction of the aircraft in-house allows for optimization of aircraft characteristics for this specific mission including payload volume, wing area, material used, camera mounting, control panel, etc.—plus, we had the best looking airplane.”
June had finally arrived, and it was time for the team to travel to Maryland where they would finally have the opportunity to fly the specified competition mission— to autonomously navigate waypoints with precision following a manual take-off, which would be performed by safety pilot, Mark Maughmer II. During the waypoint navigation, video would be transmitted to the ground station where two members would analyze targets. The landing was to be manual.
Based on previous tests performed in Austin, the UAV team predicted they would be able to accurately identify at least six to eight targets (Lat, Lon, orientation, color, shape, alphanumeric symbol, and alpha color) on Webster Field where the competition would take place.
The Flight
On the first day of the competition, the team completed its flight readiness review, breezed through the safety inspection and was informed that their team report had placed among the top six teams. Team members left the field in good spirits and with high hopes for their mission flight, which was scheduled to take place the next day.
Little did the team know what fate would have in store for the Phoenix II as they made their final preparations for the competition mission.
Harrison’s written synopsis of the flight experience tells all:
“The team set up the ground station without issue. We followed checklists and double checked that the connections were secure and battery voltages optimal. Everything went very smoothly during assembly of the station and initialization of the programs. The mission brief was delivered to the judges and everyone was ready for the mission. Once we were on the clock, we had 40 minutes to complete the mission. We could then turn on our transmitters, so we ensured that the autopilot configured properly with pre-flight checks. A range test for the safety pilot (Mark) verified the controller was operating properly, and the automatic antenna tracking station was calibrated.
"The plane was wheeled to the center of the runway, directed towards the wind. All clear commands were relayed over our team’s walkie-talkies and the propeller motor was armed. Mark then began to execute the take-off.
"At roughly 100 feet, Phoenix rolled left and appeared to stall. The aircraft then seemed to enter failsafe mode momentarily, but the spin towards the ground had already begun. There was not enough time to recover control before a nose-first impact sealed the fate of our mission. The motor mount was crushed in, the batteries had been thrown into the autopilot computer and the antenna for the receiver was severed. The plane was clearly unable to fly (even with all the replacement parts we had available to us in the pits). There was no intelligence to turn into the judges, so the full time out was taken. We returned to the pits to come up with a strategy for earning as many points as possible without an aircraft, but to no avail.
"Dr. Chaput (team faculty advisor) and Mark spoke with the judges monitoring the spectrum analyzer. From what we understand, it was discovered that local law enforcement transmitted on the frequency we were using for our remote control. Their abstinence from using that frequency was requested when Delhi Institute of Technology flew after us (they crashed on 433 MHz the previous day and replaced their plane). This interference on 433 MHz is likely the cause for the crash. Our airplane received false commands it seems.”
The Learning Experience
With heavy hearts, team members were now forced to accept the fact that the aircraft was irreparable and they would not be able to fly their mission. They had never anticipated such a disaster would occur. With the many flight tests they had conducted in the previous weeks, they had not once seen anything like what happened in the competition.
“I think we were all satisfied that we had put forth our best effort. The outcome of the flight test did not change the fact that we had developed a very good system, and we were all well trained in our roles for this mission,” Harrison said. “I was proud of what we had accomplished even though we did not have a flight demonstration to show for it.”
Despite the fact that the team was unable to complete their flight mission in the competition, the UT UAV team still placed 14th among the 26 teams.
Harrison said the learning experience was beneficial for all students involved and gave them the real-world experience of selling an unmanned aerial system to a potential customer—in this case, the military.
“Specifically, this competition reinforces the importance of testing, risk assessment and contingency planning and ensuring the safety of the system and personnel,” Harrison said. “These are key to developing a professional product. I feel that without this competition, my undergraduate experience would have been lacking this lesson.”
The best part of the experience, of course, was bringing home the paper award and $2,000 cash prize—this alone is no small feat and a testament that UT aerospace students are successfully developing and applying learned skills in systems engineering, transforming them into our future engineering leaders.
The cash award will go toward preparing for next year’s competition.
