ASCI 638, Assignment 3.6, UAS Integration in the NAS

The purpose of the Federal Aviation Administration (FAA) Next Generation (NextGen) program is to improve the daily operations of the National Airspace (NAS) System (FAA, 2016).  Unmanned aerial systems (UAS) will require the capability to interface with the infrastructure and abide by the regulations of NextGen to operate in the NAS.  Compliance with the FAA’s new program will bring challenges to UAS operations most likely similar to those faced by manned platforms.

The NextGen program plans for comprehensive airborne equipment and ground infrastructure upgrades and additional satellite resources to improve NAS operations and handling of projected increase in air traffic.  One component of NextGen is the incorporation of Automated Dependent Surveillance-Broadcast (ADS-B) by 2020.  ADS-B uses transmission and reception equipment in aircraft and on the ground to improve position tracking and separation of air traffic.  ADS-B also increases safety by providing continuously updated weather information.   Other planned components include new instrument landing systems at airfields to improve and increase safety of flight under instrument flight rules (IFR) meteorological conditions.  Additional satellite platforms will also provide improved navigation resources for aviators (FAA, 2016).

UAS operating in the NAS will benefit from implementation of the NextGen program.  ADS-B will be a valuable resource for sensing, detection, and avoidance of other air traffic.  According to the FAA (2015), a UAS operating by visual flight rules (VFR) is required to give way to all manned aircraft but not to a UAS operating under IFR (p. 4).  A pilot would need to rely on onboard sensors such as cameras or radar or have the UAS within line of sight to comply with this requirement.  A UAS operating under IFR is handled the same as manned aircraft operating under IFR, with considerations given to a specific UAS’ handling characteristics (FAA, 2015, p. 4).   IFR unmanned aircraft rely on air traffic controllers and non-visual onboard sensors to maintain safe separation from other manned or manned aircraft.  ADS-B would greatly improve situational awareness, navigation, and safety for all manned and unmanned aircraft pilots operating under VFR or IFR.  This system will also assist controllers in maintaining safe separation of air traffic.

In the event of a command, control, and communication link outage, “lost link”, a UAS must be pre-programmed with a contingency plan.  A UAS allowed to “run wild” would be a significant safety hazard.  A lost link plan will, ideally, distance a UAS from other traffic as quickly as possible, attempt to re-establish the link as soon as possible, and remove the aircraft from the air as quickly and safely as possible if required.  The FAA (2015) requires lost link procedures in a Certificate of Authorization and to be provided to air traffic controllers (p. 4).  However, mechanical and system failures are always a possibility and a UAS may not obey lost link procedures.  NextGen programs, particularly ADS-B, would assist in keeping all manned and unmanned air traffic clear of this hazard and assist operators and air traffic controllers in tracking the stricken UAS.

The design of interfaces on the UAS control console to present NextGen data will be the primary human factors issue.  The display design and format must contribute to and complement the aircraft systems information and data already being presented to the pilot.  A well designed interface will not significantly add to the existing workload on UAS operators.

           The FAA’s NextGen program promises increased situational awareness, navigation resources, and safety for increased operations in the NAS.  Manned and unmanned aircraft will benefit from the enhancements featured in NextGen.  As long as the interfaces for pilots will be user-friendly, human factors will not present a significant issue.

References:

Federal Aviation Administration.  (2016).  NextGen [Fact Sheet].  Retrieved from https://www.faa.gov/nextgen/

Federal Aviation Administration.  (2015).  Unmanned Aircraft Operations in the National

Airspace System (N JO 7210.889).  Washington DC: U.S. Government Printing Office. 

ASCI 638, Assignment 2.6, UAS GCS Human Factors Issue

  

A ground control station (GCS) for an unmanned aerial system (UAS) is the primary system through which a pilot operates the aircraft.  The composition of a GCS varies widely depending on the platform it supports.  A control system can be comprised of a modular shelter, electrical power generators, satellite communication arrays, and multiple computers, such as those used for the General Atomics MQ-9 Reaper.  A GCS can also be comprised of a single, handheld wireless controller and first person view (FPV) goggles, such as those used by FPV UAS racers.  An issue faced by FPV racers with this control system is the limited field of view for the operator.  Another issue is that the view provided by the FPV goggles during aerobatics or sharp maneuvering can be disorienting for the pilot.

            A FPV UAS operator’s field of view (FOV) is dependent on the FOV capability of the specific model of camera mounted on the aircraft.  Depending on the lens dimensions, FOVs can range from 78 to 185 degrees of FOV (Unmannedtech, 2015).  This is also assuming that parts of the UAS, such as rotors, are not obstructing the camera’s FOV.  However, despite a wide angle FOV, the pilot’s view is still limited by the fixed camera, much like flying a computer flight simulator on a single screen.  Motorized pan and tilt equipment and motion sensors would be required to allow the camera to match an operator’s head movements and provide the appropriate view.  This equipment would most likely add weight to the UAS and require additional procurement funds.  However, the benefits of this equipment may be worth the additional investment and weight.  In the video “Anti-Gravity” (2015), FPV UAS pilot “Skitzo” performs impressive aerobatics and sharp, precise maneuvers around trees and buildings.  The close clearance of the tree limbs suggests that the pilot scouted the location and planned some of his flight route.  The probability that an operator could fly such a route for the first time, sight unseen is unlikely.  The equipment necessary to allow FPV UAS pilots to look around and not be limited to a fixed forward view would improve their ability to avoid obstacles.  An alternative to motorized pan and tilt equipment and motion sensors would be a multiscreen display.  However, a multiscreen display may not provide the immersive environment provided by FPV goggles.  Whether using googles or multiple screens, good visibility and the capability to quickly scan one’s surroundings is extremely important to a pilot performing aerobatics or competing in an air race (Interview with Steve Hinton, 2012).

            Aerobatics and sharp maneuvers can cause disorientation and motion sickness in pilots flying manned aircraft.  Operators of FPV UAS have discussed in online forums that the immersive visual environment provided by FPV goggles can induce the similar reactions (Freas, 2012).  Motion sickness could degrade performance to the point where a pilot is unable to execute precise maneuvers or continue safe operations.  These symptoms could also make flying FPV UAS unpleasant enough to cause an operator to cease flying.  Freas (2012) discusses with other forum members about alternatives.  One forum member, “benderfly”, used a flatscreen video display in lieu of FPV goggles.  Another forum member, “Daemon”, related his experiences with allowing guests to watch through his FPV goggles while he flew his UAS.  Some of his guests reported disorientation and motion sickness after his flights.  “Daemon’s” guests could look in a different direction than the UAS’ heading via a full pan and tilt head tracker.  He theorized that they would become disoriented when their view rapidly shifted during his maneuvers since they were not expecting them.  “Daemon” also theorized that he did not suffer these effects since he was flying the UAS and knew when and how he was maneuvering and could anticipate the movements.

            FPV goggles are a valuable component of a racing UAS’ GCS.  The view from the UAS’ perspective aids the operator in flying the aircraft.  Improving the video systems to provide pilots a greater range of visibility would aid in navigating the course and maneuvering more tightly around obstacles.  Improved image quality could also decrease the probability of motion sickness in operators.  These enhancements would increase performance in UAS racing competitions.

References:

Anti-Gravity [Video File].  Retrieved from https://www.youtube.com/watch?v=UvhLrgvfy0w

Unmannedtech.  (2015, November 28).  FPV Cameras For Your Drone - What You Need to Know Before You Buy One.  DroneTrest.  Retrieved from http://www.dronetrest.com/t/fpv-cameras-for-your-drone-what-you-need-to-know-before-you-buy-one/1441

Interview with Steve Hinton (Part 1) Air Racers 3D IMAX – Being an Air Race Pilot [Video File].  Retrieved from https://www.youtube.com/watch?v=UDMkKUx9jKA

Freas, M.  (2012, September 7).  Adverse physical effects after flying FPV under goggles? [Msg 7].  Message posted to http://www.rcgroups.com/forums/showthread.php?t=1727642

Blog is Back!

This blog is back for Embry-Riddle's ASCI 638!  Stay tuned for more discussion posts on developments and issues on unmanned systems.

UNSY 605, Assignment 7.5, Sense and Avoid Sensor Selection

     Unmanned aerial systems’ (UAS) sensor systems for sense-and avoid (SAA) functions present a formidable challenge.  The system must provide a level of safety at least equal to that provided by a human operator’s SAA capabilities.  This threshold must be met for the Federal Aviation Administration (FAA) to approve of UAS operations in the National Airspace (NAS) and, ultimately, for the public’s approval.  A Group 2 category UAS is relatively small and light, restricting a SAA system to compact, lightweight, and power-efficient components.
    The Advanced Scientific Concepts (ASC) Peregrine 3D Flash laser detection and ranging (LIDAR) system is a suitable sensor for SAA functions on a Group 2 category UAS.  The Peregrine weighs only one pound and measures only 2 inches by 3 inches by 6 inches.  The LIDAR requires 24 watts of starting power with 13 watts for continued operation and operates at 20 Hertz.  The Peregrine features a 60 degree field of view (FOV) lens and a Class I eye-safe laser.  Figure 1 presents a view of the exterior of the Peregrine.

Figure 1.  The Peregrine 3D Flash LIDAR.

The sensor also features widely compatible support equipment and operating software.  The Peregrine can withstand environmental conditions that make it suitable for an aerial platform.  The maximum detection range of the LIDAR varies depending on laser power and the reflectivity of the detected object (“ASC”, 2015).  Tests by LIDAR technology enthusiasts have produced detection ranges of approximately 1,200 feet (400 meters) (LIDAR News Staff, 2015).
    The Peregrine LIDAR uses a solid state three-dimensional staring array.  By comparison, a LIDAR using a scanning array usually contains an oscillating mirror to sweep the laser pulses through an arc and an inertial measurement unit to measure the aircraft’s orientation.  These components ensure the position of each pulse is recorded to ensure accuracy in the data collected (Anderson et al., 2006). 
Figure 2 provides an example of a scanning array (Glennie et al., 2013).

Figure 2.  A example of a mirror and prism in a LIDAR scanning array.

The Peregrine does not require these moving parts to achieve similar results.  These properties allow for a reduction in size and weight of the overall system.  The lack of requirement for an inertial system to record orientation also means the Peregrine would be more forgiving of a carrying UAS’ maneuvers or light turbulence.  ASC’s product page (2015) explains that their LIDAR illuminates an area incorporating the FOV with a single 5 nanosecond pulse per frame.  The reflected laser light is captured in the form of three-dimensional point clouds and co-registered intensity data.  Resolution of 128 x 32 pixels can be achieved with a 4:1 aspect ratio.  Standard Ethernet ports and power connectors ensure the Peregrine is easily integrated into UAS platforms.
    The Peregrine 3D Flash LIDAR presents a SAA capability for independent operation.  SAA systems such as Automated Dependent Surveillance-Broadcast (ADS-B) have been recommended for UAS operations in the NAS (Marshall, 2013, p. 1-2).  However ADS-B relies on cooperation among aircraft and ground stations.  An aircraft without ADS-B installed will not be detected by the system.  ADS-B would also not be of any help during an encounter with a flock of large birds such as Canada geese.  A LIDAR such as the Peregrine would provide a very useful, independent SAA system to supplement ADS-B coverage.

References

Advanced Scientific Concepts (ASC).  Peregrine 3D Flash LIDAR Vision System [Product Sheet].  Retrieved from http://www.advancedscientificconcepts.com/products/Peregrine.html

Anderson, H., McGaughey, R., Reutebuch, S., Schreuder, G., & Agee, J.  (2006, July 31).  Website of Report to U.S. Forest Service, Joint Fire Science Program: The Use of High-Resolution Remotely Sensed Data in Estimating Crown Fire Behavior Variables – LIDAR Overview.  Retrieved from http://forsys.cfr.washington.edu/JFSP06/index.htm


Glennie, C., Carter, W., Shrestha, R., & Dietrich, W.  (2013, July 5).  Geodetic Imaging With Airborne LiDAR: The Earth's Surface Revealed.  Reports on Progress in Physics, 76(8).


LIDAR News Staff.  (2015, January 26).  Lower Cost Flash LIDAR.  LIDAR News.  Retrieved from http://blog.lidarnews.com/lower-cost-flash-lidar/

Marshall, P.  (2013, July 12).  The Tech That Will Make Drones Safe for Civilian Skies.  GCN.  Retrieved from https://gcn.com/articles/2013/07/12/drone-uav-sense-and-avoid-technologies-civilian-airspace.aspx

UNSY 605, Assignment 6.4, Control Station Analysis

A method of control for an unmanned ground vehicle (UGV) is a first-person view (FPV) system.  This control system allows operators to “see” from the point of view of the vehicle.  FPV control systems are useful in beyond line-of-sight (BLOS) operations, particularly in confined spaces or cluttered areas.  However, potential issues with field of view (FOV) and command, control, and communication (C3) links must be addressed with this type of control system.

            The Inspector Bots Trackbot UGV utilizes FPV in its control system.  The Trackbot is a lightweight, highly portable system (Inspector Bots, 2014).  The vehicle weighs only 10 pounds and can be transported in a single hard case.  The UGV features rubber, caterpillar-type tracks that allow the vehicle to travel over uneven terrain, obstructions, slick surfaces such as snow, inclines of up to 45 degrees, and allows it to turn 360 degrees within the space of its own footprint.  The chassis of the vehicle is also water resistant and the battery compartment provides easy access to swap batteries for continued operation.  The Trackbot’s compact design allows the UGV to enter confined spaces such as pipes, underneath vehicles, crawlspaces, and caverns.  Headlights and upgradeable infrared cameras also provide capability for low light operations (“Trackbot”, 2012).

            The control system of the Trackbot consists of a hand held control unit, transmitter, receiver, and video screen.  All control system hard/software fits into a portable hard case.  Figure 1 displays the Trackbot’s control system setup.

Figure 1.  The Trackbot’s portable control unit within its transporter case.

The video screen provides the view from the Trackbot’s on-board wide field-of-view (FOV) camera.  The Trackbot can be operated line-of-sight (LOS) using the hand held control unit.  The FPV screen is utilized for operations in which the Trackbot turns a corner in a structure or enters a confined space that prevents LOS to the operator.  The wide FOV afforded by the UGV’s camera allows the operator excellent situational awareness (“Trackbot”, 2012).

The Trackbot’s FPV system is also upgradeable to virtual reality (VR) goggle use (Inspector Bots, 2014).  The VR goggles would provide a view to the operator similar to operators of FPV racing drones.  Stock (2015) writes that FPV drone racer, Matt Denham, states that VR goggles provide an “entirely new dimension with your surroundings” and “it’s as close to being a bird as you can get”.  VR goggles would provide an immersive environment to allow a Trackbot user to operate the UGV as if he/she were the vehicle itself.  An additional improvement to the FPV system would be to utilize a motorized, gimbaled camera on the UGV.  A headset with integrated sensors would sense the orientation of the operator’s head.  Control software would link the UGV’s camera and the operator’s headset to allow the operator to look 360 degrees around the vehicle.  This improvement would provide exponentially improved situational awareness for the operator.  The immersive environment would provide benefits similar to the immersive full flight simulators used to train commercial airline pilots (AAG Staff, 2015).          

            The Trackbot’s control system utilizes a powerful transmitter and receiver to maintain C3 link between the vehicle and operator.  However, radio frequency interference can disrupt the C3 link and, potentially, control of the vehicle.  A variety of electronic equipment nearby, such as wireless/cell phones, radio towers, wi-fi routers, and power lines, can interfere with the C3 link (Derene, 2011).  This could be a particular problem with operating a Trackbot in an urban environment.  Proper bandwidth management and transmitter/receiver power would be needed to maintain the integrity of the link.  The improvement of a gimbaled camera on the UGV and linked operator headset would also require a robust C3 link and sufficient bandwidth.  These concerns would be critical to ensuring the view provided to the operator is seamless and smooth to prevent disorienting and motion-sickness inducing jerkiness.

References:
  
Alpha Aviation Group Staff.  (2015, October 30).  How AAG’s Level D Airbus A320 Full Flight Simulator Delivers Top Quality Training.  Alpha Aviation Group News and Updates.  Retrieved from http://aag.aero/how-aags-level-d-airbus-a320-full-flight-simulator-delivers-top-quality-training/

Derene, G.  (2014, March 10).  How to Fight RF Interference with Your Gadgets.  PopularMechanics.  Retrieved from http://www.popularmechanics.com/technology/gadgets/how-to/a11792/how-to-fight-rf-interference-with-your-gadgets/

Inspector Bots.  (2014).  The Trackbot [Fact Sheet].  Retrieved from http://www.inspectorbots.com/Trackbot.html

Stock, D.  (2015, August 16).  The New, Underground Sport of First-Person Drone Racing.  ArsTechnica.  Retrieved from http://arstechnica.com/gadgets/2015/08/the-new-underground-sport-of-first-person-drone-racing/

Trackbot Tracked Robot Robotic Platform [Video File].  Retrieved from

https://www.youtube.com/watch?v=7ZP90aOvJ5w