16.886 Human Factors for Autonomous Formation Flying Mary (Missy) Cummings Humans and Automation Division Aeronautics & Astronautics Formation Flight Basics ? Section v. division differences ? The tighter the formation, the higher the workload – Implications for system management ? Wingman uses significantly more fuel ? Formation flights account for 14 percent of all midairs U.S. Navy photo Autonomous Formation Flying in Action Keeping Position ? http://www.dfrc.nasa.gov/Gallery/Movie/AFF/HTML/EM-0081-01.html Refueling ? http://www.dfrc.nasa.gov/Gallery/Movie/AAR/HTML/EM-0053-01.html Position Issues ? Wing must stay within 10% of lead’s wingspan for 30% fuel savings (Proud et al., 1999): – Military: C-17: 171’, C-141: 160’, C-5: 223’ – Commercial: 747: 196’, A300: 147’ ? Previous flights – 2001: 55’ (two F/A-18s) (12% savings) – 2003: 200’ (DC-8/F/A-18) (29% savings) ? Pilots most sensitive to changes in roll – The most significant vortex disturbance when positioned for maximum drag reduction is a strong rolling moment effect (Hansen et al., 2002) ? Vortex turbulence generally avoided – Step up and down Spatial Disorientation ? A false perception of one’s position and motion with respect to the earth – Sensory illusions ? Primarily due to transition between inside/outside scans ? Especially prominent in transition between VMC/IMC in formation flying – False horizons – “The leans are most commonly felt when flying formation on the wing in the weather or at night (Wright Patt).” Vigilance Issues ? Sustained attention – Not a human strength ? Vigilance can deteriorate significantly after 30 mins ? What is the threshold for pilot intervention? – False alarms – Cost of premature pilot intervention ? Reaction times could be affected ? Alerting systems can help – Advisories versus warnings Previous Flight Test Results ? Air Force Flight Test Center, 2 & 3 T-38s – October 2001 ? Pilot workload assessments ? They found that maintaining the minimum drag formation was a comparable workload to maintaining other types of formations. (not a good thing) ? The longest duration the pilots could maintain the position operationally was approximately 20-30 minutes. – Recall vigilance discussion General Research Areas ? Alerting systems –Prediction – Probabilistic representations – Signal detection theory ? 2D versus 3D displays – Is one remarkably better or more confusing than the other? – Which one produces more false alarms? ? Situation awareness – How do these design issues impact pilot’s SA for both AFF alerting system as well as other systems? Signal Detection Theory Correct Rejection Miss False AlarmHit True in the World Pilot Response Signal Occurred Signal Did Not Occur Signal Occurred Signal Did Not Occur d’ = sensitivity to signal B = criterion Graph generated at http://psych.hanover.edu/Krantz/STD/ Receiver Operating Curves Graph generated at http://psych.hanover.edu/Krantz/STD/ 2D Versus 3D Displays ? Human is supervising, not actively flying ? Need to know where the system is now and where it is predicted to be at some point in the future. ? Is one type a better alerting system? ? Does one promote SA more than the other? Situation Awareness ? Knowing what is going on around you both now and in the near-term future – Geospatial – Temporal – System – Environmental ? Mental model – Categorization mapping ? Not the same as workload ? Automation impact Other Research Areas ? Relationship of distance/size of aircraft to pilot workload/vigilance – Ability to respond to problems/failures ? Trust issues – Stress at close ranges ? Long range missions – Both physical and cognitive fatigue ? Division issues ? Take the human out of the loop? – Ground controller