ENHANCED FLIGHT VISION SYSTEMS: PRESENCE OF RUNWAY MARKINGS AND VISIBILITY EFFECTS ON PILOT PERFORMANCE AN D R E W GR E E N H I L L S E P T E MB E R 1 5 T H , 2 0 1 7
AGENDA What is an Enhanced Flight Vision System (EFVS) • Motivation • Background • Millimeter wave radar (MMW) • Forward looking infrared (FLIR) • Light detection and ranging (LiDAR) • Situational awareness • Visual cues • Objective • Pilot performance • Research Plan • Anticipated Contributions • Proposed Timeline • 2
WHAT IS EFVS Enhanced Flight Vision Systems is defined as: “an installed aircraft system which uses an electronic means to provide a display of the forward external scene topography through the use of imaging sensors” (FAA AC 90-106A) Therefore, an EFVS must: Use real time imaging sensor , like a FLIR • Use heads-up display • Be an installed system on the aircraft • EFVS is different from both synthetic vision and enhanced vision systems Images from EFVS presentation by Terry King 3
MOTIVATION New sensors have enabled EFVS to evolve • Millimeter Wave Radar • Light Detection and Ranging • Multispectral IR • EFVS has the ability to extend the capability of aircraft operations • Landing below weather minimums • Reducing delays while waiting for weather to clear • With advancements in EFVS, the FAA is trying to get a head start on operational • approval of these systems Not just setting sensor requirements • How they affect pilot performance • 4
MILLIMETER WAVE RADAR Capabilities Constraints Penetration of various atmospheric Low resolution and noisy signals • • conditions due to frequencies in generated; clustering and filtering which it operates techniques could be required Some weather phenomenon, such Cannot detect and display runway • • as fog, light clouds, and some markings precipitation have shown to Major trade-offs between sensitivity • improve contrast and range of the sensors MMW Radar returns different • textures for different objects and terrain types Image from Yang, 1994 5
FORWARD LOOKING INFRARED (FLIR) Capabilities Constraints Thermal imaging sensor allows for Dissipation rates are different for • • night vision and low-light scenarios materials, which causes thermal reversals and ghosting • Specifically help with runway incursions Weather greatly affects the thermal • Provides distinction between • imaging capabilities concrete and grass areas at most times • Solar Load • Precipitation Can be beneficial in haze or smoke • • Wind speed Some types of FLIR can create • contrast issues by using the iHot spot technique Image from Doehler and Korn, 2006 6
LIGHT DETECTION AND RANGING (LIDAR) Although many sensors can use a Constraints combination, LiDAR typically is utilized Laser scanning techniques pose a • with an INS and GPS system safety vs. effectiveness tradeoff Capabilities Limitations with respect to • Able to detect pavement markings aerosol/cloud particles as well as • on roads and runways weather LiDAR is typically more accurate Databases for checking GPS/INS are • • compared to MMW and FLIR not fully implemented and could lead sensors, could be due to INS/GPS to extreme errors 7
SITUATIONAL AWARENESS Situational Awareness is defined as a state of Level 2 - Interpretation knowledge with three levels of perception, Correct configuration of gears and flaps • interpretation and prediction (Endsley) Appropriate speed and power settings • Level 1 - Perception On the desired glide path, typically about 3° • Flaps configuration • On the extended centerline of the runway • Gear configuration • Whether the landing will be made in the first • Airspeed for flap and gear deployment • 3 rd of the runway Power setting • When to flare during landing • Localizer deviation • Level 3 - Prediction Glideslope deviation • Travel path of traffic and conflicts • Visual of the runway centerline • Travel path of the aircraft and if it conflicts • Visual of the runway sides with any obstacles or terrain • Visual of top and bottom of the runway Location of touchdown spot on the runway • • Visual of the touchdown markers What the next objective of the mission is and • • how to get there Visual of the horizon • 8
VISUAL CUES Visual cues for approach and landing Level 1 - Perception mainly include: Flaps configuration • Terrain • Gear configuration • Airport Environment • Airspeed for flap and gear deployment • Power setting • Factors of a stabilized approach • Localizer deviation • The main visual cues of a stabilized approach are part of Level 1 situational Glideslope deviation • awareness Visual of the runway centerline • Visual of the runway sides • Visual of top and bottom of the runway • Visual of the touchdown markers • Visual of the horizon • Image from Marks, 2017 9
SITUATIONAL AWARENESS AND VISUAL CUES •Glideslope deviation In the figure, the Level 2 situational On the desired glide •Visual of top and bottom of awareness tasks on the left path, typically about 3° runway •Visual of the horizon To the right of each Level 2 task, are the Level 1 tasks that directly •Localizer deviation affect it On the extended •Visual of the runway centerline centerline of the •Visual of runway sides Certain forms of EFVS have: runway •Visual of the touchdown markers Range issues - Blue • No way of displaying runway • •Visual of the touchdown Whether the landing markers markings - Red will be made in the first •Visual of top and bottom of 3 rd of the runway runway •Visual of runway sides When to flare during •Visual of top and bottom of landing runway •Visual of the horizon 10
OBJECTIVE The objective is twofold: Find the effect of how the visibility range of an EFVS affects the pilot performance on • approach and landing Find the effect that the absence of runway markings in EFVS has on the pilot • performance during approach and landing Sensor Visual Situational Properties Cues Awareness Display Characteristics 11
FITTING IN PILOT PERFORMANCE Pilot performance for approach and The stabilized approach criteria align landing can be measured primarily by with level 2 of situational awareness a stabilized approach and some other factors Sensor properties A stabilized approach is when the following criteria are met: Correct configuration of gears and flaps • Visual cues (Level 1 situational awareness) Appropriate speed and power settings • On the desired glide path, typically • about 3° Level 2 situational awareness (Stabilized On the extended centerline of the • approach criteria) runway Whether the landing will be made in the • first 3 rd of the runway Pilot performance 12
EXPERIMENTAL SETUP Simulator Hardware 4 separate monitors • Three make up the • outside view of the environment The fourth screen is • the instrument panel. A yoke • Rudder pedals • Throttle control • system Eye tracker • 13
INDEPENDENT AND DEPENDENT VARIABLES Independent Variables Dependent Variables Presence of runway markings in Stabilized approach criteria • • EFVS • Localizer/glideslope error • Binary true or false Altitude • Visibility range of EFVS • Vertical speed • • Fluctuates between 1, 3 or 12 statue miles Airspeed • Heading • Latitude and longitude • 14
EXPERIMENT DESIGN Subjects Scenarios 21 pilots would be tested Each pilot would fly seven different • approaches, listed below, these would Must be instrument rated and have • be fully balanced using a Latin square a minimum of 150 hours Basic approach, no EFVS • Base Conditions Approach with EFVS, runway markings and 12 • Start at a 5 nautical mile approach • sm visibility Approach with EFVS, runway markings and 3 • Be placed on the glideslope in a • sm visibility cruise condition Approach with EFVS, runway markings and 1 • No flaps added yet • sm visibility The nav instruments would be • Approach with EFVS, no runway markings and • 12 sm visibility tuned into the localizer/glideslope Approach with EFVS, no runway markings and 3 • sm visibility Approach with EFVS, no runway markings and 1 • sm visibility 15
ANTICIPATED CONTRIBUTIONS Identify possible drawbacks or specific benefits of using EFVS • Specifically with respect to pilot performance during approach and landing • Results will be utilized in: • Issuing operational approvals for EFVS • Providing limitations for EFVS • The focus on specific visual cues, will hopefully allow the results to be more • operationally applied than sensor specific requirements Planned papers • Previous literature review concerning the topic of EFVS • Paper summarizing the objective and results of the thesis • 16
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