fiber optic project (for university, help required)

[cameron_john]

hello all,
i have just started my second year of university, i am studying aircraft engineering and we have been tasked with a year long project that will ultimately play a large part in our final grade.

the basic brief for the project is to come up with, or innovate upon any aspect of an aircraft (non-military) it will involve a 10,000 word report.

i am looking at doing the project on the replacement of copper wires in aircraft with fiber optics.

within the coarse so far we have only had the basic classes covering logic and basic theory. i have an external interest in electronics from a young age and have done several projects on my own, simple things like a headphone amp in a tin..but enough to involve getting a board and soldiering components in.

now i am aware power transfer via fiber optics is not as efficient as copper, however as far as information transfer (radar, sensors as well as control surface commands) due to the bandwidth multiple signals could be transferred via a single lead (with a backup) hopefully saving weight. Cost is an issue, but as this is a project the time scale can extend to a point where the price of fiber optics would make it a viable alternative.


The bit i need help with.

i would like to make a simple mock up as part of my final demonstration, actually make a working fibre optic transfer system. i once saw a system where audio was transferred in a fairly simplistic looking system, with what looked like a pulsating led (probably a simple laser) something like that would be ideal (transfer of data, moving a servo would be the bee's knee's)

first thing is first, getting the basic system working, but i would like to go as far as having a mock up control setup.

budgets not huge on my part, but the uni says it will supply any parts it can get free of charge (but i assume i will need to purchase some of the more specialized stuff)


so there we go, can anybody help me?

this is my first post also, my name is John, and i look forward to hearing from you

 

[(*steve*)]

Well, the first question you need to ask yourself is "What are the strengths and weaknesses of copper wires in this application?" and then "How can fibre optic perform better?"

You might look at some recent aircraft incidents to try to determine what problems there are to be solved.

You might, for instance, look at the turbine disc failure on the Qantas A380. Parts of the disc severed cables carrying control information to/from the engine. When those were severed, the engine was stuck at the last power setting and also could not be shut off.

Would fibre optic have helped? If it results in a significant enough weight saving then maybe it would allow for a duplicated data path through some other part of the wing?

Perhaps something else would be more beneficial? Maybe bluetooth? (although in practice you wouldn't use something so easily accessible to the passengers )

The whole point is, look for problems needing solutions, not solutions needing problems.

 

[cameron_john]

thanks for the reply!

the main advantages of fiber optics i can see are,

high bandwidth, low signal loss, immune to emi and other noise, secure signal, no risks of sparks, weight less than copper, corrosion resistant.

there are probably many many more.

you make a good point, that aside from general weigh saving, the overall safety of on board systems could be improved by having multiple backup connections to the same device, so if as in that incident one is severed, normal operation can continue(that concept could play a large part)

unfortunately wireless technologies tend not to be used on board aircraft (aside for passenger utilities, wi-fi for example, and uhf radio for external comms) as they are deemed too at risk to interference.

"The whole point is, look for problems needing solutions, not solutions needing problems"

haha, very well said, and very true

 

[Digital_Angel_316]

I agree with Steve. I would like to see a proposal that is a result of market research
with a set of comparisons and tradeoffs with a brief technical analysis that leads you
into further work on your project. It would include a bibliography - two simple examples
of which are below.

I would look into the various fiber optic network topologies also, they are well
documented and understood and can be summarized in a diagram and a page of text.
I would look into Mil-Std-1553 data bus for communications and it's fiber optic cousin
Mil-Std-1773. Another keyword for review would be FDDI (Fiber Distributed Data
Interface.

I don't know much about a 10,000 word report so much as a set of documents that
show the design process (re-posted from another thread on this forum below).

• PROPOSAL
• REQUIREMENTS SPECIFICATION
• DESIGN SPECIFICATION
• DESIGN DISCLOSURE

With appropriate use of tables/charts/spreadsheets and graphs and diagrams and
careful references to your bibliography, you might be able to stay within your 10k word
total budget. The process is critically important -- the technology is the
implementation of the requirements, good science and good engineering.

Reference articles (2):
(1) Fiber Optics on a Plane:

Monday, September 25, 2006 By Kate Greene
Monday, S than a hundred miles of electrical wires in the average plane, controlling
nearly everything from landing gear to flight-attendant calls. All that insulated copper
wire is a big liability: it's heavy, it's susceptible to electromagnetic interference, and
when not properly maintained, it can cause system failures and fires.
http://www.technologyreview.com/Infotech/17533/

(2) Under federal contract, Northrop Grumman seeks to
replace copper-based aircraft wire, cabling with carbon nanotubes

Nov 10, 2010
Nanocomp Technologies, Inc. (Concord, NH), a developer of energy-saving performance
materials and component products from carbon nanotubes (CNTs), announced it has
been awarded a manufacturing contract from Northrop Grumman under the U.S. Army
Manufacturing Technology Program (ManTech).


http://www.interconnectionworld.com...ace/2010/november/under-federal_contract.html


Posted from a previous thread regarding a University Project approach on this forum:

I would start the project with a Requirements Specification, your professor
(teacher?) should require it. Detail the features and functions that are
required. A rough draft outline may be just a page or two. Follow up when
you have had a peer review with others on your team to finalize at least a draft
copy. Make a table of Frequencies, Times, User Interactions, Outputs and
Processing. It may contain a simple block diagram and flow chart of the
requirements (a processor is not a requirement, it is an implementation detail).
You should also develop a simple SCHEDULE and BUDGET outline. This should
be presented to your professor as a key milestone of your work effort and each
subsequent design phase should also go through peer review and higher level
(professor, boss, client, customer) review and acceptance.

The next step is to develop a Design Specification. This will take the
REQUIREMENTS and relate them to an implementable design. It is not until
this step that you concern yourself with choosing components. The DESIGN
implementation is inferred from the REQUIREMENTS.

From there you can begin to think about design implementation details. What
input devices, what processor, what output mechanisms (switches,
Ucontrollers, speakers, printers, recording media, packaging, layout etc.)

Finish up with a Design Disclosure document. This will describe the theory of
operation, have a block diagram and flow chart and walk through the
operation. Much of it can be pulled from the Requirements and Design
Specifications if done properly. This will also include a Schematic, Code
listings Bill of Materials, and perhaps operating instructions (to save you from
writing a 'Users Manual' which some might also require depending on the
project scope)

The PROCESS is just as (more) important than the implementation. You could
do it on a PC, in a cell phone app or a dedicated device you design and build.
The requirements will drive these sorts of selections and involve Research and
Tradeoffs.

Sorry, I took out all the fun and haphazard approach. It is a real discipline to
walk through the design process. In the end it saves a lot of time and money
from false starts, misunderstood 'requires and desires' and provides greater
satisfaction to the designer (or design team) and most imortantly to the
'customer' / end-user.

Time and cost constraints are a part of the tradeoff process and the above
mentioned process is not completely linear / sequential. You may already
have a favored platform or development tools, or expertise for example that
leads you to 'require' certain implementation details -- same concept with
budgetary aspects.

Best wishes and Godspeed. Get back to us when you are further into the
project.

Self-healing Ring Topology ..........................................................................Star Network Topology ........................................Bus Network with Backbone