UAS Integration in the NAS ASCI 638 - 3.6

 

Figure 1. UAS in the NAS (Cameron, 2012)

“NextGen is the FAA-led modernization of our nation’s air transportation system” (What is NextGen, 2017).  The goal is to increase safety and efficiency in the national airspace. Replacing ground based navaids, such as an NDB or VOR, with GPS based airways. Radar would be replaced with Satellite GPS tracking and Automatic Dependent Surveillance-Broadcast (ADS-B) of aircraft for ATC. These combined will enable aircraft to fly closer together, yet still safely, since the location is more accurate and up to date compared to radar. More direct routes are able to be taken with GPS than ground based navaids which decreases fuel consumption, brings down the overall cost of the trip and reduces transportation time (What is NextGen, 2017).  

ATC needs to be able to communicate with the UAS controller whenever the UAS is in controlled airspace.  Since the UAS controller is on the ground, and most likely not in line-of-sight communication with ATC the UAS could be used to relay the communication to the ground controller via satellite communications (Pongracz & Palik, 2012).  This would allow direct communication with the UAS controller and it would be similar to contacting an onboard pilot. Of course, this only works for larger UASs, most notable military controlled UASs that have access to satellite communications.  An example would be the Global Hawk that uses Satcom to relay UHF/VHF communication between ATC and the ground controller (Global Hawk UAS, 2018).

According to the Federal Aviation Regulation (FAR) 14CFR 91.111(b) “the operator of an aircraft must maintain vigilance so as to see and avoid other aircraft. The operator must also give way to other aircraft if they have the right of way”.  Since a UAS cannot see to avoid it needs to “sense and avoid”.  ADS-B is used to broadcast to ATC the position, altitude and velocity of an aircraft. Having ADS-B built into a UAS would enable ATC to locate the UAS, any aircraft or person with an ADS-B receiver and let the UAS know of other aircraft in its vicinity and it could navigate to stay clear of the manned aircraft. A company called UASioni has released a line of small ADS-Bs that could easily be fitted into a small UAS, some of these are only an inch by an inch in size (ADS-B Transceivers, n.d.).  

PrecisionHawk has developed Low Altitude Tracking and Avoidance System, or LATAS. LATAS is “onboard system that provides flight planning, tracking and avoidance for every drone in the sky using real-time flight data transmission based on existing world-wide cellular networks” (Say Hello, 2015).  LATAS uses existing cell towers to transmit a UASs location to ATC, which would relay that position to pilots in the area. This is a small bit of electronics, about one inch by two inches, that can be added to any UAS during manufacturing.

NextGen will need to address human factors the same way the previous National Airspace system (OldGen? Maybe PreviousGen?) needed to. We will still have crew rest, human inattention, human mistakes, a need for well designed human machine interface and crew resource management just to name a few. With the advent of ADS-B receivers there has been an advancement in safety. Previously a pilot needed to be visually scanning outside the cockpit when flying VFR, and even IFR at times if not in the clouds, in order to see-and-avoid other aircraft. While this is still a necessity the use of ADS-B has enabled pilots to be able to see other aircraft relative to their position on a moving map or digital display in today’s glass cockpits. If a UAS had an ADS-B transmitting it location even a small hard to visually see UAS will be prominently displayed on a screen for other pilots in the area.

When we fully upgrade to NextGen, or if everyone starts using ADS-B while still fying ground based navaids human factors will always be an issue. We need to continue to train, improve and stay vigilant as members of the aviation industry. As with all aviation it takes skilled people, on the ground, in the tower or in the sky to make it all work safely. 

  

References

ADS-B Transceivers, Receivers and Navigation Systems for Drones (n.d.). Retrieved January 28, 2018 from http://www.unmannedsystemstechnology.com/company/UASionix-corporation/

Cameron, A. (2012, May 22). The System: Fly the Pilotless Skies: UAS and UAV. Retrieved January 28, 2018, from http://gpsworld.com/the-system-fly-the-pilotless-skies-uas-and-uav/

Say Hello to LATAS (January 09, 2015). Retrieved January 28, 2018 from http://www.precisionhawk.com/media/topic/say-hello-to-latas/

Global Hawk UAS of NASA. (2018). Retrieved January 28, 2018, from https://directory.eoportal.org/web/eoportal/airborne-sensors/content/-/article/global-hawk

What is NextGen? (2017, November 21). Retrieved January 28, 2018, from https://www.faa.gov/nextgen/what_is_nextgen/

UAS GCS Human Factors Issue ASCI 638 - 2.6

Predator RQ-1

The RQ-1 Predator is a long-endurance, medium-altitude UAS for surveillance and reconnaissance missions and interdiction. Imagery is provided from synthetic aperture radar, video cameras and a forward-looking infrared (FLIR) can be sent real-time to the front-line soldier, operational commandeer or worldwide via satellite communications. It can be armed with AGM-114 Hellfire missiles.  The ground control station (GCS) is a single 30 foot trailer, containing pilot and payload operator consoles, three Boeing data exploitation and mission planning consoles and two synthetic aperture rater workstations. It is launched with direct line-of-sight control from a semi-improved surface. Line-of-sight data link or satellite links produce continuous video for the operators and all controls are commanded through those communication channels (Predator RQ-1, n.d.).

One human factors issues that lead to an accident was the design of a control lever made it easy to create a mishap. The GCS has two operators who sit at identical consoles. One operator is the pilot and the other is the payload operator. When configured for the pilot the condition lever will start or stop fuel flow and can feather the propeller to reduce drag. When configured for the payload operator the same condition lever will operate the iris on the camera. Per the checklist if control is transferred from one console to the other the condition lever on the payload console must be set to match the pilot console prior to transfer of controls. During a control transfer the checklist was not followed and the condition lever was not matched. Once the transfer of controls was completed the conditions lever which had been set to control the iris was not set to stop fuel flow to the engine, causing the engine to shut down. This was a major contributing factor to a Predator crash in 2016 in Arizona (Carrigan, Long, Cumming & Duffner, n.d.)

This failure mode could be designed out of the system. Something as simple as having two distinct condition levers, one for the iris control and a separate for engine control.  Another would be to prevent or give a warning if pilot control transfer is attempted and the condition lever is not matched between the two control consoles (Carrigan, Long, Cumming & Duffner, n.d.). “While some would advocate for more training to address this problem, humans are imperfect systems, and it is important to design for an operator that may make mistakes” (Carrigan, Long, Cumming & Duffner, n.d.).

Human factors in cockpit design occurs both in unmanned and manned aircraft systems. The cockpit needs to be designed in such as way as to allow the pilot to be efficient and comfortable as possible.  “One of the first formal human factors studies was carried out by Fitts and Jones in 1947 to analyze pilot experiences with display readings” (Flying Towards the Future).  In the late 1970s cockpits had an excess of 100 individual components the pilots were required to monitor and manage, the technology at the time only allowed for a gauge to display one piece of information (Salas, E., Maurino, 2010).

Another human factors issue is the limited field of view for the Predator operator. The original design of the GCS gave approximately a 30-degree field of view from the nose camera. It was stated that it is similar to “driving your care with paper towel tubes over your eyes” (Shiner, 2001). This is shown on one screen for the pilot overlayed with information such as transponder code, airspeed and

Original GCS Cockpit   (It's Better to Share, 2011)

altitude. A second screen providing data such as a map with a symbol of the aircraft and the corridor for its’ route of flight. This limited field of view, and the lack of vestibular and proprioceptive cues, means the pilots rely on visual cues to fly, such as when the runway fills the bottom third of the screen the nose is raised to flare prior to touchdown.

Raytheon designed a new cockpit for the GCS that now has three wide screens and a 270-degree field of view with some synthetic data overlayed. This allows for a large increase in the pilot’s situational awareness. This improved display along with more ergonomic controls, more comfortable

Advanced GCS (Pocock, 2007)

and adjustable seat as well as new interfaces increases the comfort of the pilot as well as their situational awareness (Pocock, 2007).

Limited field of view can occur with manned aircraft as well.  Many military and civilian pilots fly at night under Night Vision Devices (NVD) such as night vision goggles. These goggles limit the field of view to around 40-degrees. The pilot overcomes this limitation by increasing scan rate, looking left and right frequently and not relying on peripheral vision in order to see surroundings.

References

Carrigan, G., Long, D., Cummings, M., & Duffner, J. (n.d.). Human Factors Analysis of Predator B Crash [Scholarly project]. Retrieved January 21, 2018, from https://hal.pratt.duke.edu/sites/hal.pratt.duke.edu/files/u13/Human%20Factors%20Analysis%20of%20Predator%20B%20Crash%20.pdf

Flying Towards the Future: An Overview of Cockpit Technologies (October, 2013). Retrieved January 21, 2018 from http://www.ergonomics.org.uk/flying-towards-the-future/ 

Its Better to Share: Breaking Down UAV GCS Barriers. (2011, October 03). Retrieved January 21, 2018, from https://www.defenseindustrydaily.com/uav-ground-control-solutions-06175/

Pocock, C. (2007, June 16). New UAV Control System May Cut Predator Losses. Retrieved January 21, 2018, from https://www.ainonline.com/aviation-news/defense/2007-06-16/new-uav-control-system-may-cut-predator-losses

Predator RQ-1 / MQ-1 / MQ-9 Reaper UAV. (n.d.). Retrieved January 21, 2018, from http://www.airforce-technology.com/projects/predator-uav/

Salas, E., Maurino, D. E. (2010). Human factors in aviation (2nd ed.). Amsterdam: Academic

            Press/Elsevier

Shiner, L. (2001, April 30). Predator: First Watch. Retrieved January 21, 2018, from https://www.airspacemag.com/military-aviation/predator-first-watch-2096836/?all

Case Analysis Effectiveness ASCI 530 9.4 Research Blog

Peer Review (Dilbert, n.d.)

Overall I appreciated and learned from the peer review process and case analysis within ASCI 530. It was useful to develop my final research paper in several stages, and have it peer reviewed to improve upon it with an outside perspective. We all have most likely written something knowing full well what we intended to say and believing we did. But we misstated something or didn't clarify it enough and needed a set of outside eyes to spot the mistake.

The peer review was helpful and I took many of the comments made by my two reviewers into account and they ended up in the final research paper. One of my reviewers reordered my entire introduction sections, combined paragraphs and moved ideas around. I ended up taking all the comments into account and the final introduction looked vastly different from the rough draft introduction. It ended up being organized much better, with a clearer flow between thoughts.  Without the outside eyes I would not have improved this section of my paper.

Peer review, or collaborative effort, is a large part of my current job and past ones as well. Prior to going to active duty with the military I was a design engineer for Caterpillar. Any design I created would be roughed in by me to prove a concept. I would then share the idea with others asking for improvements and sustains on the design. These would be taken into account for the final version of a design, which itself was vetted by someone else to ensure accuracy and effectiveness. Designs would be constantly displayed to peers either in PowerPoint or with the CAD software projected and discussed to ensure all design requirements were met. 

With the Army I fly Blackhawks. Decisions for how I will execute a flight, what to use as a VFR check point, altitudes, airspeed, approach directions, night vision device considerations, safety, fuel requirements... are all discussed at a minimum with my copilot. Many times I will discuss them with other pilots to ensure I'm not missing something. In a large mission all of the information is put into a PowerPoint and presented to many other pilots so they can vet my decisions as well. Other pilots have different experiences than I do and will normally catch something I did not think of. Their assistance ensures my success in missions.

The one suggestion I would have for this course is to split the research paper up into three parts for peer review. Currently there is a peer review for the abstract, then another for the rough draft. In both cases we had to respond to what comments we would incorporate and what would be ignored, with justifications. I would like to see this broken up into three separate peer reviews.

The first peer review would cover the abstract, as we currently do it in this course. The second would cover the first three sections of the paper; Summary, Issue or Problem and Significance of the Problem. This would focus the student on those three topics as well as giving the peer reviewer less review, allowing them to pay more attention and perhaps do more research themselves into the topic and suggest different issues or problems.  The third peer review would cover Development of Alternative Actions and Recommendation. The same peer reviewer should be used and they would then look over the second peer review to see what changed, then focus their efforts on the last two sections of the paper.  I believe the splitting up the work allows for more focused efforts in the details of the paper, which could then lead to a better, more professional product overall.




Reference:
Dilbert by Scott Adams (n.d.). Retrieved from http://dilbert.com/

Request for Proposal ASCI 530 7.4 Research Blog

UAS Over Wildfire (Folk, 2017)

When battling a wildfire, the firefighters need accurate, real time information where any hotspots are occurring and what direction the fire is moving.  “The conditions wildfires produce make it nearly impossible to obtain real-time situational awareness, especially at night when it’s too dangerous to fly manned aircraft over the flames” (Knight, 2015). This means that in the morning firefighters have little to no idea what occurred with the fire overnight. UAS can provide real time information on the fire, both day and night, allowing critical decisions to be correctly made by the firefighters on the ground. Developing a UAS that can observe hotspots is essential in aiding firefighters.

1.     
Transportability

a.      Entire system (all elements) shall be transportable (in a hardened case) and weight less than 50lbs (one-person lift)

b.     Transportation case shall be designed to fit in the back of a standard SUV (21 cubic feet)

c.      Transportation case shall have a foam interior for protection of sub components

d.     Transportation case shall have cut outs for all sub components of the system

e.      Transportation case shall have cut outs for any tools required for the assembly/disassembly of the UAS system

f.      Transportation case shall provide impact protection for all components inside the case

2.     Air Vehicle Element

a.      Shall be capable of resisting particles created by wildfire such as ash

b.     Shall be resistant to rainfall up to ¼ inch per hour for one hour

c.      Shall be able to “return to home” if data link with the ground control station is lost for more than fifteen seconds

d.     Shall be multi-rotor capable of autonomous stabilized hover

3.     Payload

a.      Shall have thermal infrared camera for detection of hotspots

b.     All video feed shall be receivable by ground control element

c.      Shall have a day video camera for detection of observable smoke

d.     Shall be gyro stabilized for flight

Testing

1.      Transportability

a.      Conduct weight roll up for all off the shelf components and customized parts to ensure total weight is below 50 lbs. Weight final prototype (all elements) to ensure weight is below lbs.

b.     Inspect transportation case to ensure total volume is less than 21 cubic feet

c.      Inspect transportation case to ensure foam interior is present

d.     Test fit all sub components into their respective cut outs in the foam

e.      Test fil all tools for assembly/disassembly into their respective cut outs in the foam

f.      Drop case, loaded with all sub components and tools, from height of five feet to ensure case and components are undamaged from fall

2.     Air Vehicle Element

a.      Perform ground tests to ensure all components are not affected by ash. Provide gaskets/barriers if issues arise and retest

b.     Perform ground run in a controlled environment subjecting UAS to ¼ inch of rain flow in one hour. Provide gaskets/barriers if issues arise and retest

c.      Utilize hardware in loop simulations to ensure UAS will return to home if communication is lost for more than fifteen seconds. Followed by test flights in a controlled environment once software is validated

d.     Utilize hardware in the loop simulations to ensure UAS is capable of stabilized autonomous hover. Conduct test flights in a controlled environment once software is validated

3.     Payload

a.      Conduct thermal infrared test on video equipment to ensure proper operation and resolution at 1000 feet AGL

b.     Conduct tests to ensure all video feed is received by ground control stations at altitude up to 1000 feet AGL

c.      Conduct test of visible light camera to ensure proper operation and resolution at 1000 feet AGL

d.     Utilize hardware in the loop simulations to ensure UAS is capable of stabilized flight. Conduct test flights in a controlled environment once software is validated

Schedule

·       Phase Description – Duration (months)

o   Concept Design - 3

o   Concept Research - 3

o   Preliminary Design - 3

o   Detail Design - 6

o   Specimen Test - 6

o   Prototype Build/Test - 6

o   Modification - 3

o   Certification - 6

o   Production – 24 (total production run, 1 week per UAS)

o   Support – 60

Conclusion

            The air vehicle needs to withstand both weather and smoke/ash generated by the fire. Therefore, I decided on the requirement to handle ¼ in of rainfall per hour. This UAS will be electric as opposed to an engine to combat ash particles. There is no air intake and no combustion chamber to be damaged by means of ash particles. Sealing the inside of the platform with close fitting panels and gaskets will keep most of the ash out. 21 cubic feet for the total volume of the transportation container was chosen since this is the volume of the cargo compartment on a Ford Explorer (2017 Explorer, n.d.).  This is a common sized SUV to be used, and would also ensure it would fit in the back of a pick-up.

            1000 ft AGL was determined to be the needed hover and flight height of the UAS. The initial design requirement was for 500 ft AGL but this UAS will work at higher altitudes. This will ensure there is room for growth within the UAS platform, if next year the customer requests 600 ft AGL it is already validated at that altitude. IR cameras are to be used to detect hotspots as well as allowing the operator to see through smoke for operations in degraded visual elements (Allison, Johnston & Jennings, 2016). Visible light cameras are the be used for flight during the daytime as well as visually detecting smoke which can be a cue for a potential hot spot (Allison, Johnston & Jennings, 2016).

            
           This project has a three-year timeline from concept design to certification. Concept design/research and preliminary design are high level, broad tasks. More time is allocated to detail design, specimen test and prototype build/test.  These are more time consuming and detail oriented, more time is needed to ensure everything is done correctly. Production is estimated to build one UAS per week for a period of two years. Support will run concurrently and for a period of five years total. 

References

Allison, R., Johnston, J., Craig, G., & Jennings, S. (2016, August 18). Airborne Optical and Thermal Remote Sensing for Wildfire Detection and Monitoring. Retrieved from http://www.mdpi.com/1424-8220/16/8/1310/htm

Folk, E. (2017, October 04). Drones Could Be the Answer to Containing Forest Fires. Retrieved from https://www.cleantechloops.com/drones-forest-fires/

Knight, R. (2015, December 09). UAS Fighting Wildfires. Retrieved from http://insideunmannedsystems.com/fighting-wildfires/

2017 Ford Explorer (n.d.). Retrieved from https://www.ford.com/suvs/explorer/2017/models/explorer/

Drones for Anti-Poaching ASCI 530 6.4 Research Blog

Drones are being used in Africa as an anti-poaching tool. Poaching is taking a significant toll on the wildlife population. Over a seven-year period the elephant population declined by 30% and in 2015 around 1300 rhinos were killed for their horns (Nuwer, 2017). Many conservations are utilizing drones to prevent or deter poaching. Poachers can be identified in the park via a camera on a drone. At this point many times the drone is flown directly at the poachers, alerting them to the fact they are being watched, and they flee the area.  Another is to reduce animals contact with humans, by keeping them inside a protected refuge. “DJI Phantom drones can steer elephants away from park boundaries — likely because they sound like a bit like bees, and elephants hate bees” (Nuwer, 2017).

Super Bat (Super Bat, n.d.)

The Super Bat DA-50 is currently being used in Tanzania by the National Park Service (Corrigan, 2017). It is gas powered, fully autonomous with a ceiling of 15,000 feet with an endurance of ten hours. It includes a 20 megapixel camera that can send live video feed to the operator, and can 
automatically follow track and follow targets. Small enough to fit into an SUV, including the catapult to launch. It also has the ability to fly up to 50nm line-of-site from the command center (Super Bat, n.d.). 

Air Shepherd ZT-TIC (Air Shepherd, n.d.)

The Air Shepherd ZT-TIC was developed specifically for anti-poaching and is in use in several parks in Africa. Fully electric with a service ceiling of 4000 feet and an endurance of around five hours. It includes a day and a night camera capable of sending live video feed to an operator up to 30km away. Can fly an automated route and has a control range of 50km line-of-site (Air Shepherd, n.d.).

The long endurance, high altitude, powerful camera and range make the Bat and Air Shepard ideal for covering the large land area that encompasses most refuges. They can both cover a large area of ground faster than anyone on foot or by ground vehicle, both of which could alert poachers to the rangers looking to catch them.  They typical employment of one of these drones is to determine, based on past patterns, where poachers are most likely to enter the park and operate.  Rangers are prepositioned on the ground and the drone is sent up to survey the area. Once poachers are identified the Rangers are sent in to apprehend them (Air Shepard, n.d.). 

The DJI Inspire is in use in Zimbabwe, the Phantom is also in use at the same locations. The Inspire is fully electric with an endurance of 13-18 minutes. With a fully independent camera and a dedicated remote for the camera (Inspire 1 Pro/Raw, n.d.). The Inspire has three advantages over the other two drones listed above. The pure ease of use means little required and any park officer can use one. It’s fully packable and can be easily transported anywhere within the park with just a backpack. The ability to hover means a more precise location and stable images, which is needed for any law proceedings where the poachers are being brought to trial.

DJI Inspire (Inspire 1 Pro/Raw, n.d)

The main disadvantages are that with such a short endurance and range limit this is more of a reactionary tactic. Poachers are identified and the Inspire is sent in to gather images of the criminal act as it’s happening.  It is used in conjunction with a fixed wing. Its powerful camera is the main advantage (Corrigan, 2017).

One of the biggest challenges to using drones for anti-poaching is the efficacy is yet to be determined.  Air Shepherd has made some very large claims about how effective they are.  They claim in a one-year period over a designated area there was a 65% reduction in rhino poaching. The second year they operated there, after learning from the first year and improving tactics, there were no rhino poaching deaths at all, leading to a 100% effectiveness (Corrigan, 2017).  It is important to point out here that this was a study done by Air Shepherd, the company selling drones to that area. It was not peer reviewed or replicated elsewhere. There are many articles claiming how effective drones are, but all the ones I came across ultimately lead back to Air Shepherd as their source material for the data.

There have also been anti-poaching drone operators that show up to national parks promising to stop poaching claiming they have done it in the past. These groups charge a lot of money and fly gas-powered drones low to the ground. These drones lack sensors or cameras of any type, relying on the noise to prevent poaching.  These are likened to snake oil salesman as they claim to stop poaching entirely. Even though poaching in the areas they cover remained the same.  This left many parks hesitant to try drones for anti-poaching as they had wasted valuable money on fraud (Mortimer, 2017).

Kruger National Park, which straddles the border of South Africa and Mozambique, stopped their drone experiment earlier this year. Using Air Shepherd drones, they noted that the results were very disappointing, and no poachers were seen or apprehended (Mortimer, 2017). While the technology is promising on the surface, a lot more development and research needs to be completed. No long-term studies have been done on drones for anti-poaching.

Another large issue facing drones for anti-poaching are that drones are becoming banned in some countries in Africa. Kenya banned all drone activity from wildlife refuges and all private use drones.  Kenya sites “security concerns” over this decision and has stopped any and all research being done in Kenya for anti-poaching drones (Koebler, 2014). South Africa also banned flying drones with cameras for commercial use, the vagueness of the wording meant that all drones with cameras were grounded, including those used for conservation (Andrews, 2015). With a fine of up to 10 years on prison, conservationists aren't willing to risk that they are an exception to the rule (Andrews, 2015).

  

References:

Andrews, C. (2015, April 25). The Promise of Drones in South Africa's Poaching Crisis. Retrieved from https://motherboard.vice.com/en_us/article/bmjaxa/the-promise-of-drones-in-south-africas-poaching-crisis

Air Shepherd. (n.d). Retrieved from http://airshepherd.org/

Corrigan, F. (2017, January 29). 8 Top Anti Poaching Drones For Critical Wildlife Protection. Retrieved from https://www.dronezon.com/drones-for-good/wildlife-conservation-protection-using-anti-poaching-drones-technology/  

Inspire 1 Pro/Raw. (n.d.). Retrieved from https://www.dji.com/inspire-1-pro-and-raw?site=brandsite&from=landing_page

Koebler, J. (2014, June 04). African Nations Are Banning the Drones That Could Stop Poachers. Retrieved from https://motherboard.vice.com/en_us/article/pgaapz/african-nations-are-banning-the-drones-that-could-stop-poachers

Mortimer, G. (2017, March 28). Kruger Park, South Africa, Stops Anti-Poaching Drone Experiment. Retrieved from https://www.suasnews.com/2017/03/kruger-park-south-africa-stops-anti-poaching-drone-experiment/

Nuwer, R. (2017, March 13). High Above, Drones Keep Watchful Eyes on Wildlife in Africa. Retrieved from https://www.nytimes.com/2017/03/13/science/drones-africa-poachers-wildlife.html

Super Bat. (n.d.). Retrieved from http://martinuav.com/uav-products/super-bat-da-50/

UAS in the NAS - ASCI 530 4.5 Research Blog

ATC needs to be able to communicate with the UAS controller whenever the UAV is in controlled airspace.  Since the UAS controller is on the ground, and most likely not in line-of-sight communication with ATC the UAS could be used to relay the communication to the ground controller via satellite communications (Pongracz & Palik, 2012).  This would allow direct communication with the UAS controller and it would be similar to contacting an on board pilot. Of course, this only works for larger UASs, most notable military controlled UASs that have access to satellite communications.

 

According to the Federal Aviation Regulation (FAR) 14CFR 91.111(b) “the operator of an aircraft must maintain vigilance so as to see and avoid other aircraft. The operator must also give way to other aircraft if they have the right of way”.  Since a UAS cannot see to avoid it needs to “sense and avoid”.  Automatic Dependent Surveillance-Broadcast (ADS-B) is used to broadcast to ATC the position, altitude and velocity of an aircraft. Having ADS-B built into a UAS would enable ATC to locate the UAS, any aircraft or person with an ADS-B receiver and let the UAS know of other aircraft in its vicinity and it could navigate to stay clear of the manned aircraft. A company called uAvioni has released a line of small ADS-Bs that could easily be fitted into a small UAS, some of these are only an inch by an inch in size (ADS-B Transceivers, n.d.).   

PrecisionHawk has developed Low Altitude Tracking and Avoidance System, or LATAS. LATAS is “onboard system that provides flight planning, tracking and avoidance for every drone in the sky using real-time flight data transmission based on existing world-wide cellular networks” (Say Hello, 2015).  LATAS uses existing cell towers to transmit a UAVs location to ATC, which would relay that position to pilots in the area. This is a small bit of electronics, about one inch by two inches, that can be added to any UAV during manufacturing. 

(Say Hello, 2015)

These are some options for controlling a UAS in the national airspace. As with all aviation it takes skilled people, on the ground, in the tower or in the sky to make it all work safely. Even with sense and avoid systems in place, aviation personnel will still need to remain vigilant and aware. 

  

References

ADS-B Transceivers, Receivers and Navigation Systems for Drones (n.d.). Retrieved from http://www.unmannedsystemstechnology.com/company/uavionix-corporation/

Say Hello to LATAS (January 09, 2015). Retrieved from http://www.precisionhawk.com/media/topic/say-hello-to-latas/

Weeding out a Solution - ASCI 530 2.5 Research Blog

UAS Sprayer 1 (Agricultural UAV, 2016)

Problem:

 A UAS is to be designed for precision crop-dusting. In the middle of the design process, the system is found to be overweight.

• Two subsystems – 1) Guidance, Navigation & Control [flying correctly] and 2) Payload delivery [spraying correctly] have attempted to save costs by purchasing off-the-shelf hardware, rather than a custom design, resulting in both going over their originally allotted weight budgets. Each team has suggested that the OTHER team reduce weight to compensate.
• The UAS will not be able to carry sufficient weight to spread the specified (Marketing has already talked this up to customers) amount of fertilizer over the specified area without cutting into the fuel margin. The safety engineers are uncomfortable with the idea of changing the fuel margin at all.

Write a response describing how you, as the Systems Engineer, would go about resolving this issue. Use your imagination, and try to capture what you would really do. Take into account and express in your writing the things you’ve learned so far in this module: What are your considerations? What are your priorities? What do you think about the future prospects for the “next generation, enhanced” version of the system as a result of your approach?

My Response:

My priority for this issue is to ensure we deliver the end product that marketing has promised, we can precisely deliver the allotted volume of fertilizer in the correct location with the needed endurance for the UAS.  My second and third priorities are to ensure we are within budget by a few percent and within the promised time frame within reason.  If a UAS is delivered as promised but a few percent more in cost is better than a UAS that doesn’t deliver as marketed but costs what was promised. The initial purchase is a onetime pain for the end user, and can be overcome when the seasonal use of the UAS goes off as promised.  Same thing with the timeline. If it is late by a small amount of time, say within a month, then the repeated seasonal use of a functioning product will most likely overcome the late delivery.  Of course, all attempts will be made to deliver on budget, time, payload and endurance. “Build the right system, and build the system right” (Cantor & Roose, 2006).

I would go to the lead Guidance, Navigation & Control engineer and lead Payload delivery engineer in two separate meetings, both with the same structure.  I’d like to see the weight roll up of all parts they are responsible for.  Using this we would go after the heaviest parts first, and go from there. Assuming the heaviest part is the off the shelf purchase I would ask the engineer to talk to the supplier.  If the supplier knows our requirements, they may have alternative solutions that do not come with the same weight.   The main competitors of the suppliers should also be contacted. If they also know our requirements, to include cost and timeline, they may have a solution the current supplier does not.

What are the options for creating our own systems that are not off the shelf? Again, the suppliers would need to be contacted and a discussion had.  Most likely their parts have some ability to be interchanged within themselves.  If we don’t purchase a box full of electronic components from the supplier, but instead we purchase only some of the electronics inside we may have an opportunity for weight reduction. They have a packaged product that delivers to all of the end users, which may have features we do not need.

I would also let every engineer on the project know we are having weight issues. Perhaps another system has a means to reduce weight which will offset the added weight from these two systems. An example of saving weight is to look at something simple such as brackets and hardware. Let’s take a simple L bracket and discuss ways to reduce weight.  If you have two flat plates that are welded to form the L a flat plate bent into an L would be lighter. It’s also likely a bent bracket would be cheaper as there is less labor and handling on the manufactures end. Assuming the L bracket has holes for mounting if we add welded nuts to it that would reduce the total part count for hardware required, by eliminating the washer that would go under a loose nut.  One washer is not significant, but if you do that all over the UAS is does start to add up. This would also reduce labor time on our end for assembly as well as less total parts that need to be stored along the assembly line.

 Is there a place to use rivets instead of bolts/nuts/washers? Is there places to use bends instead of welds? Working with the suppliers of any mounting brackets they would be able to offer solutions to save weight or cost. Can we change the material? If it’s currently steel is there an option to make it out of some form of plastic? An L bracket is straight forward and not likely to save much, however a fully enclosed box with mounting hardware in it starts to open possibilities.  I spent years as an engineer and would work with suppliers often to reduce weight and cost, they normally had ideas since they built the parts for us.  The ideas varied from changing steel types, removing extra gussets or decreasing their sizes, changing hardware configurations, riveting not bolting or bending instead of welding.

UAS Sprayer 2 (Agricultural UAV, 2016)

Making any changes to hardware or the electronics would have benefits down the line. In the future generations of our product we have already started to customize the “off the shelf” products to our needs. We started the relationship with the supplier now, and any future programs can be started with the supplier from the beginning, instead of later on into the project as is the case now.  Working with suppliers to possibly modify brackets and mounting hardware also educates our engineers on this topic and they can start to design hardware more intelligently. Which would reduce design iterations and save on cost of the engineer’s time.

There is a balance to strike with cost and timeline, however in the end we have to deliver a usable product.  A systems engineer can’t deliver everything required. The “job is not to satisfy all needs, but to select a profitable and practical subset of those needs and attempt to deliver” (Gilb, 2006).  If we focus on delivering the right product, this will pay off in the long run for our company.  

References

Agriculture UAV Crop Dusters Agriculture UAV Sprayers Platforms. (2016, December 21). Retrieved from http://www.uavcropdustersprayers.com/

Glibb, T. (2006). Some Powerful Systems Engineering Heuristics. SE Heuristics.

Cantor, M., & Roose, G. (2006, March 18). The Six Principles of Systems Engineering. Retrieved from http://websphere.sys-con.com/node/196077