Sunday, December 21, 2014

Case Analysis Effectiveness

This is the first class in which I have done a Case Analysis of this kind, and perhaps because of the small number of people in the class, it did not seem to be terribly effective. I never received any real feedback on my paper other than “it looks good, keep going”. I feel that the whole process would have worked better if the course had not been online. If we had been able to sit down together each week and bounce ideas off of each other. The obvious response to this is that I should have used the message board more, but I find that a five minute face to face conversation can solve more than a week of back and forth on the boards.

In the writing of the paper, I did find the list of learning objectives on the syllabus to be very helpful. It kept me on topic and gave me some very specific questions to answer with my research.

As far as practical application, the Case Analysis tool does not have any direct application in my day job of repairing radios and aerospace navigation equipment. However, I do see the benefit moving forward, as I hope to eventually be a part of a team that designs and builds UAS. The recommendations portion of the Case Analysis is probably the most important in that regard. I see the value in using an accumulation of research to recommend corrective action for the future of a design project. All of the design projects I am involved in now are part of my hobbies, and so I work on them alone. However, as part of a team, well thought out recommendations would be very valuable.

Sunday, November 30, 2014

Task Specific UAS Design

As the popularity of unmanned aerial systems grows many different groups have tailored designs to fit their particular need. Unmanned systems have been proposed to do everything from providing worldwide cell and wifi service, to replacing your mailman. However, the times when UAS shine the brightest is when they can perform a task that prevents a human from risking life and limb. Many unmanned systems have been designed or modified to  assist firefighters by detecting and tracking fires and also by delivering water directly onto the blaze.

Just this month a joint team from Lockheed Martin partnered with Kuman unmanned aircraft gave a demonstration of a K-MAX helicopter with an upgraded sensor package that was able to autonomously detect fires and deliver up to 680 gallons of water per trip (Gabbert, 2014). Originally a manned helicopter, the K-MAX was converted to a UAS by Lockheed back in 2007. The K-Max has a  high payload to weight ratio and this made it an ideal choice for a water delivery system (K-MAX, 2014).

Back in 2007 the United States Forest Service bought 2 SkySeer UAS to help monitor wildfires. The SkySeer is much better at tracking fires because it’s infrared cameras are not hindered by the smoke. Unfortunately, due to current FAA regulations the Forest Service is not allowed to operate UAS (Gabbert, 2013). The SkySeer is small, lightweight, and with a price tag around $30,000, much less expensive than other options (Bowes, 2006).

The lifting capacity of the K-MAX and the low cost of the SkySeer make them well suited for assisting firefighters, especially when it comes to battling forest fires.

References:

Bowes, P. (2006, June 6). Retrieved November 29, 2014, from http://news.bbc.co.uk/2/hi/americas/5051142.stm

Gabbert, W. (2014, November 18). Fire Aviation. Retrieved November 29, 2014, from http://fireaviation.com/tag/uav/

Gabbert, W. (2013, December 4). Fire Aviation. Retrieved November 29, 2014, from http://fireaviation.com/2013/12/04/forest-service-not-using-100000-drones/

K-MAX. (2014, July 1). Retrieved November 29, 2014, from http://www.lockheedmartin.com/us/products/kmax.html

Sunday, November 16, 2014

UAV integration into the NAS

Deconfliction of small and medium scale UAVs comes down to data-link capability. Loading such an aircraft down with all the sensors required to detect and avoid other aircraft is simply not cost effective. However, given a reliable data link, each aircraft can report it’s own position to a central ATC facility and receive warnings about potential hazards at the same time. However, even sending these updates once a second can be a huge amount of data with enough aircraft in the sky. The DoD estimates the needed data throughput at 20 Gbps for a fleet of some 700 drones. While this data rate itself is not insurmountable, when you consider that it must be reliable and available over a large geographic area, the situation becomes more complicated. While this estimate includes the video and control feeds, it does give an idea of the order of magnitude of bandwidth needed. By that I mean that a military drone has a much higher need for an HD video feed for target designation and surveillance reasons than a standard civilian cargo UAV would need (Milsat, 2012).

Once the use of data links helps UAVs avoid each other, then each individual aircraft can worry about avoiding other obstacles, such as birds. The difficulty of this task decreases rapidly with increasing altitude. Also, most of these obstacles move relatively slow when compared to aircraft, providing a slightly longer timescale to detect and avoid them.

References:

Furstenberg, D. (2012, March 1). Intel: Meeting The Growing Bandwidth Demands Of A Modern Military. Retrieved November 13, 2014, from http://www.milsatmagazine.com/story.php?number=855426811

Sunday, November 2, 2014

Systems Engineering - Conflict Resolution

In the event that a systems engineer must act as an intermediary between two groups that have gone outside their design specifications in order to reduced cost there are many different things that must be considered
In this example the Navigation & Control team  and the Payload delivery team have both gone over their weight allowance in order to use COTS hardware in an attempt to reduce cost and production time. In order to get the project back on track the systems engineer needs to consider several different aspects of the problem:

How much to both systems weigh, and by what percentage did they go over the allotted weight limit?
How close is the production deadline and how much time and money will it likely cost in order to design custom systems for both approaches?
How much of a benefit is COTS hardware?

The first question is important because the system that weighs more will probably have an easier time reducing its weight. For example, if the amount that the Payload team went over was more than the entire weight of the navigation system, then there is no point asking the Nav team to try and make up the slack.
The second aspect is time. If production is far enough out, both teams can be expected to give plans for alternate, lower weight (although higher cost) systems. Obviously this is not always an option, but having both teams attack the problem will often yield better results than insisting that any 1 team fix the problem alone.
The third question is about determining how much of a benefit you are getting out of COTS hardware in the first place. There are many possible benefits including reduced cost, availability of parts, and warranties. All of these things must be weighed against the cost of redesigning large systems of the UAS in order to meet the weight requirements.

During the process of attempting to validate the weight requirements it is important to keep the customer in the loop. They need to know up front about the potential cost overrun that will come with keeping to the original design specifications. At that point, they can make the decision if they would rather have reduced capability or increased cost (Loewen, 2013).

References:
Loewen, H. (2013). Requirements-Based UAV Design Process Explained. MicroPilot.

Sunday, October 26, 2014

The AQM-34Q Firebee and the MQ-9 Reaper: Then and Now

The Teledyne-Ryan AQM-34Q Combat Dawn Firebee was converted from a target drone to a reconnaissance aircraft after a North Korean MIG shot down a manned reconnaissance aircraft killing the entire crew. The Firebee was only able to stay aloft for a maximum of 8 hours with the use of external fuel tanks, but this was offset by its ability to maintain high-subsonic flight and its ceiling around 75,000 feet. This remarkably adapted drone was able to intercept radio signals from hundreds of miles away and transmit them back to sensor operators. Like many early unmanned aircraft it suffered from difficulties in recovery. Unable to land itself, it would deploy a parachute and then be recovered in the air or splash down in the ocean (AQM-34Q).
Over the years, the need for extended surveillance became apparent, and unmanned aircraft designs changed to fit the new mission requirements. For example, in order to stay over a target to gain visual information, high-subsonic flight is probably not the best fit. The MQ-9 Reaper was designed with these lessons in mind. By utilizing a turboprop instead of a turbojet engine the top speed was reduced to around 230 miles per hour, but the tradeoff was a huge increase in endurance to over 24 hours. The reaper is also equipped with 6 wing stations capable of carrying munitions. This allows the crew to not only observe, but to react if necessary. Because of the number of sensors on board, it requires a two man crew to operate. One to pilot and another to operate the surveillance equipment (MQ-9).
Disregarding the fact that almost 40 years passed between the first use of the AQM-34Q for surveillance and the initial operation of the MQ-9, one major difference stands out when considering the design and the effectiveness of the two platforms. The Reaper was designed with a specific role in mind from the drawing board, whereas the Firebee was made from several components duct taped together to fit a newly realized niche. This key difference shows the growth of the industry over those four decades.




References:

Factsheet: Teledyne-Ryan AQM-34Q Combat Dawn Firebee. (2014, April 15). Retrieved
October 23, 2014, from http://www.nationalmuseum.af.mil/factsheets/factsheet.asp?id=4044

Factsheet: MQ-9 Reaper. (2010, August 18). Retrieved October 23, 2014, from http://www.af.mil/AboutUs/FactSheets/Display/tabid/224/Article/104470/mq-9-reaper.aspx