Future Automotive Wiring: Fiber Optics

[ExplorerDMB]

Fiber Optics​

It has been brought to my attention recently that fiber optics is the new way for automotive wiring. A few technicians at my work have been to a few classes regarding it and some of the information on it. Fiber Optics is using "light" instead of normal non-visible current. Light is sent through a delivery fiber and reflects off the microcantilever. The reflected light is then sent through a collection fiber to a photon detector. The new, fiber-optic based sensors will be energy efficient, inexpensive, accurate, and immune to eltromagnetic interference - qualities that will ultimately improve the performance and efficiency of power electronic inverters by enabling very precise switching. Obviously, most fiber optic technology is being used in the new hybrid vehicles (some). BMW, Lexus, and all the lead manufacturers in the automotive world are currently using fiber-optics.

Benefits:

-Reduced weight and volume
-Fast, accurate measuremets
-Cheaper to manufacture and lower life-cycle costs through better long term operation.
-Functions in the harsh enviroment of an automobile; high temperature operational capabilities.
-Not affected by electromagnetic or radio frequency interference.


There are, however, disadvantages to using fiber optics. Splicing fiber cables requires skills not yet learned by many professionals. Fiber cables are also nonconductive. So, if an electrical communication link is needed, then an additional conducting member will need to be added to the total cable configuration. Optical fibers are made from glass; which in turn will decay when exposed to water over a long period of time. Water breaks down the glass and will eventually cause disintegration. Despite the cost, fiber does not last forever. One other disadvantage is that if the wire does become useless - you will (right now) have to replace to whole wire from end to end; which can be a long and intensive job.

I am not exactly "all knowing" in this technology, so if anyone has anything else to add; please do so. I would be interested in learning anything new.

-Drew

 

[IronCamel]

We actually covered this at a computer conference recently. They were discussing innovations to lower costs in order to help American carmakers get back into the black. You hit on the biggest points, but there is one advantage they haven't talked about yet. They're waiting for the nerds to hammer out how to make it work reliably.

The other major advantage to this is actually a byproduct of home theatre and computer integration. It will allow a vehicles electrical system to perform as a mini netowork that can be self repairing with computer aid. It will allow engineers to build systems that automaticaly reroute signals to good cables when others fail bypassing the problem. This would allow the vehicle to operate temoprarily till it could be taken in for servicing. It would reduce downtime due to minor issues.

The MAJOR disadvantage will be a diminished ability for DIY since these systems will probably be proprietary and difficult to alter without problems.

 

[Glacier991]

Also remember that a multiplexed system is already here. In a multiplexed system, just like computers, there is a main bus that handles all the traffic, and interrupts will allow servicing of individual component requests - just like how our computers work - instead of having each component have its own wire to the computer as has been the case... FORD calls their multiplexed system CAN (Computer Area Network)... BMW and Mercedes are already a few years into their systems.

I wonder how fiber optics will play into multiplexed systems?

 

[BrooklynBay]

Some vehicles have some small scale optical fibers in use. A neighbor of mine has a small car alarm installation shop. His worker thought that a fiber in one of the doors was a ground wire, and cut it for some unknown reason. It was for the turn signal on a mirror! The light was actually mounted somewhere else (possibly in the door, or another location in the vehicle). When he cut the cable, he wasn't able to repair it. I wonder if heat shrink tubing would work on it, or possible a barrel crimp? I know that they make some sort of coupling (maybe like a compression coupling). I think a regular crimp might cut through it.

 

[ExplorerDMB]

I don't think you can do that. Fiber optics uses light source - so if you crimp it you'll be squeezing the ends together which will reduce the light feed. May cause issues with the lighting source (turn signal), but if it was feeding a computer and it wasn't seeing exactly what it ssuppose to...only more issues.

-Drew

 

[Doug]

I wonder if they're going to use true fiber optics or just optical cables (ala home theater surround sound). I'm 3m certified in ST/FC/SC hot melt & expoy connectors as well as mechanical and fusion splicing. If they plan on using "true" fiber optics I don't see where the cost saving is. fiber optic cable is expensive, the connectors are expensive, and the tools to make the cables are very expensive.

To give you an idea how expensive the cables are a 3ft SC-SC cable like a commercial router would use is about 120 dollars. Some of the equipment I work on has fiber optics in it. A basic fiber kit which would give you the connector heater, polishing stone/paper/holders, cleaving tool, cutting tool, strippers,a basic scope, etc. will run you about $2000. If you want a decent scope you're looking at another 2000 easily. There is also fiber testing equipment to tell you how much loss there is over your cable (I beleive you want .03 db or less but it's been a while) and the testing equipment starts at around 2000 and goes up from there.

Making fiber optic cables is tedious work, you're dealing with a piece of glass thinner than a human hair. Considering the costs of the tools, the labor involved in building the cables this isn't a do it yourself kind of thing. HOWEVER I wouldn't be suprised if automobile manufacturers would go with something more like an optical cable your home stereo system would use. Those cables are an optical grade plastic and are much cheaper to manufacture than traditional fiber. Even if they did use something along those lines aftermarket modification would be more of a challenge not to mention if you damaged one of the cables replacing/ repairing it would become much more difficult.

I don't think we're ever going to see total use of fiber in vehicles for a long time if ever. I would imagine they're using fiber to connect items like the ECU, Gem, navigation systems, transmission control, etc. I think fiber will mostly change the way we modify the engine controls on our vehicles. In time I imagine the aftermarket will catch up so instead of cleaning off the pins on the ecu to make your chip work correctly you'll just be popping out the fiber connecter and plugging your chip inline with the ecu. Not to mention if everything is networked in that fashion imagine what one aftermarket part could manage? It could allow you to customize everything from engine control, to transmission shift points to how everything in the vehicle's electrical system operates.

 

[spindlecone]

Wonder what it cost for comcast to run buried 3 inch FO cable on my street last year, never hooked up to any homes

 

[Glacier991]

There are optical cables, and fiber optic cables. Fiber optic cables handle each hair thin fiber as a separate channel. Optical cables are unitary, one piece of light carrying cabling - usually a core of some plastic (not THAT small) sheathed with a cover and can be used for either light transmission (as in the Olympus Endoscopes doctors use to look inside your (ok ok TMI) and FORD uses to illuminate the turn signals in mirrors. Those are used to carry a single channel of LIGHT, not information.

Fiber optic cables are another matter entirely. They consist of bundled strands that carry modulated light as and for information.

Woe be unto the guy who acidentally digs up a 3 inch FIBER OPTIC CABLE. I bet that repair bill could be way into the tens or even hundreds of thousands of dollars.

Moral... Call USA before U DIG !

 

[d-wolf]

fiber optics

just wanted to add that fiber optics were used in american made automobiles during the 70's and 80's,not sure about other years. optics were used 2 illuminate the ash trays in ford and gm cars,may have ben used in other areas as well. i used 2 own a 71 torino boss,its ash tray was lit this way,i now own a 92 gmc vandura conversion van,its ash tray is also lit by fiber otics. as for newer cars,all i've owened have normal lighting in ashtrays. my 98 PONTAIC GTX SUPERCHARAGED NASCAR ED. DOESN'T HAVE ANY FIBER OPTICS NOR DOES MY 98 EXPLORER XLT V8 AWD OR MY 98 PORSCHE 928 SE4 V8 WITH 6 SPEED. REASON I NO THIS IS EVER CAR I BUY,I REMOVE ALL INTERRIOR,DASH,ECT TO DO UPGRADES. STEREO ECT.I'VE STRIPED OUT SO MANY CARS, I'VE GOTTEN 2 WHERE I CAN DO THIS IN ABOUT 10 MIN. GIVE OR TAKE A MIN OR TWO UNDER NORMAL CONDITIONS,UNLESS THERES A STUCK BOLT OR SOMETHING HOLDING ME UP. IF ANYONE EVER NEEDS ADVICE ON REMOVING ANY PART OF THE INTERRIOR OF A VEHICLE,HIT ME UP,I'VE PROBABLY DONE IT.I ALSO HAVE OWNED A DETAIL SHOP FOR OVER 20 YRS. WE STRIP NEARLY EVER CAR 2 CLEAN EVERTHING,MAKES FOR AN INTERRIOR THAT LOOKS AS CLOSE 2 UNUSED AS POSSIABLE. THE USED AUTO DEALERS HERE ARE REALLY PICKY AND INSIST ON THIS.SO , IF ANYONE NEEDS ANY HELP,YELL. D-WOLF

 

[IZwack]

Caps lock issues.

 

[briwayjones]

How does water decay the glass? Glass(silicon) does not decay or chemically weather.