Slashdot Mirror
How Wireless Meshing Could Save Energy
An anonymous reader writes "EE Times reports that the future of industrial automation lies in wireless mesh sensor networks. From the article: 'It is the holy grail of the factory floor: hundreds of sensors wirelessly connected, monitoring motors for problems and drastically reducing energy consumption -- all with the precision and rhythm of a philharmonic orchestra.' (Other articles here(1), here(2), and here(3).)"
My dad told me stories of Back In The Day(tm) when AM radio stations would broadcast at 300,000 watts, or more, and streetlights would be lit by the radiant energy. Can't imagine that did people much good living near the antennas...
A feeling of having made the same mistake before: Deja Foobar
...welcome our new job-stealing wireless mechanical overlords.
Seriously, though, this would make my job a whole lot easier...monitoring the operation of a pair of 8MW generators (or a host of other equipment) from a single location vice constantly hopping around from point-to-point looking at every little gage and meter gets real old, real fast.
Given all the slashdot stories about Wardriving and the like, how secure would these networks be? What prevents a competor with a wireless broadcast anteanna from parking in range of your factory, and sending false signals telling your machines to idle?
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You realize, of course, that just means they'd give you more work to make up for what they took away. Right?
Easily done. Just make then in China where all our factories have been relocated.
Worded with a different spin, the tagline could sound all too familiar:
An anonymous reader writes "EE Times reports that the future of police monitoring lies in wireless mesh sensor networks. From the article: 'It is the holy grail of law enforcement: hundreds of sensors wirelessly connected, monitoring citizens for problems and drastically reducing energy consumption -- all with the precision and rhythm of a philharmonic orchestra.'
OK, maybe not a philharmonic orchestra -- a bean burrito perhaps.
This idea strikes me as an implementation or extension of "Munchkins" described in an ancient (1996) paper by Rohit Khare and Adam Rifkin.
The idea basically describes very small, low-power devices that can route messages between each other until they find the target device (or a valid route to the target device). I have to wonder whether new devices like the iPAQ with GSM, WiFi, and Bluetooth are trending towards this behaviour. It wouldn't take a heck of a lot to turn the iPAQ 6340 into a device that can intelligently route incoming packets over any of its connections.
I'd love to be able to pick up my cellphone, and connect to my PC via a network of industrial sensors built into traffic signals, bus stops or the nearest ATM.
gadgetophile.com
As the devices "run for years off a single battery", seems unlikely to pose much of a threat, even in aggregate.
Looking for a Rails developer in Chapel Hill?
Not necessarily. If something were to go wrong with the internals of a machine, odds are better that an electronic sensor would detect the problem before the operator would...a problem detected before serious damage occurs is a lot easier to deal with (and would require less work) than one detected when it causes a component (or an entire machine) to fail.
If the energy is low enough it's probably no worse than that green tan you've been developing from fluorescent lights. I'm miffed about all the stray 2.4 GHz signals whick keep knocking off my satellite radio -- It's a wonder the park isn't filled with mutant squirrels or Man-Spiders or something.
A feeling of having made the same mistake before: Deja Foobar
Either that or he'd get laid off.
I've got more mod points and GMail invi
For the record, I'm an electrical equipment operator in the USN...fortunately (or unfortunately, depending on one's POV), I can't lose my job to automation. If the government were ever willing to change their stance on that point, however, I'm sure I wouldn't be *too* disappointed...
The station transmitted to all of Europe via the powerful transmitter site in Marnach on 1439 kHz (later 1440 kHz), 208 metres in the medium wave band. The transmitter pumped out 1300 kW and was Europe's most powerful (only hit by a Russian site which had more power). Radio Luxembourg ceased transmissions from the 208 transmitter December 30. 1991 to be available on satellite and short wave only. Unfortunately CLT decided to close the station at the end of 1992 because it made no money out of the programmes. Luxy returned on the great 208 for one night only - the date when the station's final programme was aired - December 30. 1992.
http://slashdot.org/~GuyFawkes/journal
Having installed wired and wireless networking on manufacturing floors I can tell you that before this dream of magic wireless connectivity comes true, these machines will need vastly better RF shielding. We had a bugger of a time getting wireless to work and even wired networks would act up if you were not careful where you placed the wires. (One company ran fiber optic to the floor machines because the interference issue couldn't be resolved satisfactorily: not a cheap way to go).
So how long will it take to get those machines updated? Well, one of my first jobs out of the U was making a tape punch work on a PC so they could edit programs and load them from paper tape. That was in 1990. I'm guessing that these will be a great concept for someone building a factory floor from scratch, but retrofitting is going to be a big flop.
Sig under construction since 1998.
I thought P2P communication was supposed to be evil.
For those interested in this kind of wireless mesh for the home check out zensys. I dont have any links or handy info, I just know they work in the same way and are intended for home automation. Lightswitches, thermostats etc.
Safty and reliability are absolutes in industrial control.
A machine like a bottler goes down at pepsi, and they are losing $250k/min when that machine isn't running. Or a pharmacutical company drops a batch worth $3 million. And now that I've climbed in or on huge presses, mixing tanks, 6ft. fans, high preasure steam, and poison vapors... I wouldn't trust thier function to a wireless web.
I can see where this would be great for remote/hazardess sensors and transmittion, but not anytime soon for control. Hell, we still extensivly use rs232 over ethernet.
I am billdar, and I approve this message.
Well, all of the conventional methods of monitoring the equipment would most likely be left installed as a backup for the sensor network (redundancy is a big deal in our field). If the network went down, the operator would resort to monitoring the machines the old-fashioned way, by reading gages and meters.
This is pretty sweet. This way, you don't have to waste more energy by putting a transformer onto the motor's circuit. The best part is that it uses energy that you're normally wasting anyway.
Show me on the doll where his noodly appendage touched you.
Mod me down if you must, but whenever I think of automation on a scale like this I can't help but think of that robot-building factory in Episode II.
Well that, and an 'I, Robot' quote, "Robots building robots... Now that's just stupid."
"...Well, there's egg and bacon; egg sausage and bacon; egg and spam; egg bacon and spam; egg bacon sausage and spam..."
The electric charactaristics of a machine change when it's broken. I don't really understand how putting sensors everywhere will improve that situation rather than just managing eletronic load. For that matter, doesn't wireless need much energy?
Since when has this country used intellectual elite as a pejorative term?
all with the precision and rhythm of a philharmonic orchestra
Didn't John Cage describe an orchestra as an instrument of destruction?
Besides, the focus is understandably across the board, but some industries use vastly more energy than others. Somehow this seems like almost trivial energy use compared to say aluminum processing.
Next time someone throws out "free market" when talking about jobs, it would be prudent to drag this example out.
Politicus
Therefore I don't have high hopes for energy saving via a new energy saving system. I can see visions of technicians rushing around in gas-guzzling trucks to go install/upgrade/repair sensors. Once all the sums are done I don't expect an energy saving.
Engineering is the art of compromise.
Or a pharmacutical company drops a batch worth $3 million.
Uh-huh. That is $3 million retail. The cost of the dropped batch is more like $1500.
Am I the only one that read the title as: "Hot Wireless Meshing" Where's Bender when you need him?
Usually, but for most devices under the 2m wavelength mark (>150MHz or so, which these would probably be), human body absorbption drops quickly.
Of course, this is moot when compared to the EMI that most industrial electrical equipment generates. Hundreds of 3-phase motors, giant transformers, and multi-kilowatt circuits make for a far stronger field at the low end of the spectrum than an army of small sub-watt range transmitters.
Either humans will evolve to read these wireless signals constantly being beamed around us (sort of like a sixth sense)...or...well...we'll all develop cancer from it's radioactive waves.
Real programmers can write assembly code in any language. -- Larry Wall
It's really much closer to the $3 million.
It's called 'opportunity cost', and it's real.
To exaggerate the situation, to make a point, what if they had 'dropped' every batch all year ?
(maybe 1 batch a day)
And you are a stockholder.
What would you say if they said "we really only lost a half million dollars" ?
What about the salaries of all the people on the job, all the equipment being amortized, etc.
The real cost is what they should have been raking in on that batch, and could have utilized the equipment for, etc.
Lost opportunity.
> It is the holy grail of the factory floor:...
Well, here in the U.S. it isn't clear that we'll
have any factories left in the near future to test
this out in.
Just as you point out how automation hasn't reduced labor, but shifted it away from repetitive manual jobs, so wireless monitoring has the potential to free up time and energy to be diverted to some other task. One possibility is that more sensors would be deployed, allowing more detailed analysis of failures. Or more devices requiring monitoring would be deployed, since fewer physical visits would be needed to maintain them.
Most industrial motors are used to drive steady-state processes, and are always on. Examples, are drive motors used in pulp mills and refineries. I don't see how any amount of mesh network monitoring is going to drastically save electricity for these always-on motors. A small savings might be found by looking for inefficiencies in the way the motor operates (i.e. it needs maintenance). However, I find the claims of 10-20 percent savings by monitoring somewhat questionable.
For discrestionary motors, like tank filling pumps, there could be some savings found by using the mesh network to control the asset during off-peak hours, where often the electricity rates are lower.
Sounds great. When this is implemented, $25 in electronics will be able to shut down an entire factory. Sorry, but even if the only potential attacker is a l33t pranksta, I'd have to advise NOT using wireless sensors.
For that matter, I've been wondering when someone would jam EZ-Pass one afternoon and turn Manhattan into solid gridlock.
there's a research project about sensor networks going on at the Swedish Institute for Computer Science (SICS): http://www.sics.se/cna/dtnsn/. one of the researchers, Adam Dunkels, is the guy who posted a TCP/IP stack written in PHP a while ago.
Until someone brought a cell phone in and the whole system went haywire...
The main article and here(1) don't say. All the sensor network would do is sense vibration, temperature, etc. But no explanation of how this would help save energy. Here(2) was farked, I mean slashdotted. Here(3) provides clues: "allowing plant personnel to repair or replace motors before their production capacity drops or they fail entirely," and, "the two-way communications network will enable the use of control applications. For example, if a monitoring system is being used on a generator and has sent notification that it is running too hot, the monitoring personnel could issue wireless commands back to the generator for it to turn on its exhaust fan."
I can see the usefulness of doing these things in terms of fewer breakdowns, but where is the energy-saving tie in, particularly the claim that the sensor system will "increase a motor's efficiency by 10 to 20 percent" ???
First off, this isn't going to save anything in the way of electricity. Somebody's smoking crack on that one.
:)
Other than those motors that people forget to shutoff. But if that's the case, why aren't they controlled by a PLC already?
This network would (hopefully) only be used to annunciate faults/transmit data. They wouldn't be used for control of the equipment (that is until some smooth-talking salesman convinced some idiot to do so). So cracking into the network with dreams of pulling a "Suki" would be a bit farfetched.
And surprise, surprise, much of our newer equipment is already on the network. So worrying about this is peanuts compared to the potential cockup of having your equipment rooted. And we have had systems nearly go down when someone without authorization hooked up to our network and spread a worm. The PLC was getting hammered so hard that it was causing the equipment to act erratically.
This in conjunction with the spread of OSes that are "off the shelf" (be they Windows or be they Linux) instead of being designed solely for the purpose of running the PLC (Programmable Logic Controller) is a disaster waiting to happen. Add consumer hardware to the mix and things get real interesting.
Case in point, not too long ago we had the plant shut down when someone moved a PC to get the serial number off it for an audit. This would not have happened if the equipment was controlled using industrial hardware.
But it was amusing...
However, this will help by way of allowing the plant to monitor motors and allow maintenance to replace/repair them at their convenience. That's a good thing
John
I dream in binary.
Radio Luxembourg is, however, most famous as the source of the "Luxembourg effect." In 1933, shortly after these powerful transmissions started, its modulation was heard in the Netherlands, mixed with that of a German station on another frequency (1). It was soon proposed that this occurred because Radio Luxembourg's signal was so powerful it was heating the ionosphere, producing a nonlinear condition that mixed the two AM signals (2). This effect has since been studied by the HAARP (High Frequency Active Auroral Research Program) in Alaska.
As an aside, B. D. H. Telegen, the discoverer of the Luxembourg effect, was quite an interesting guy. He also invented the pentode vacuum tube (valve).
(1) Telegen, B. D. H., Interaction between radio waves? , Nature, 6, 369, 1933
(2) Bailey, V.A. and D.F. Martyn, Influence of electric waves on the ionosphere, Phil. Mag., 23, 369, 1934
Almost correct. You need AES-128 authentication and message integrity checking, not encryption, but ZigBee has both. Encryption merely makes the message private, but authentication ensures that the source address wasn't spoofed, and integrity checking ensures that it hasn't been corrupted or modified before reaching the recipient.
BTW, the IEEE 802.15.4 spec is available for free download.
What about interference?
Around my area I can detect about 10 linksys routers most using the 2.4ghz freq. I get disconnects every once and a while on my laptop from it.
Will these "hundreds" of wifi devices all use a different frequency? How would they communicate?
If energy saving is the goal, desktop computers should be replaced first. There is no reason why a regular desktop PC should consume 400 Watts, these days - at most companies they are even left on at night. Remember all those energy saving ads about replacing your 100 Watts light balls?
Assuming this e-mail address is valid and has a human at the other end...
I use 'END COMMUNICATION' at the end of my posts for the same reason as people use signatures at the end of their post. Because it amuses me. Because it sounds abrupt and borderline hostile. Because it actually looks like it might belong at the end of a forum post or e-mail.
That, and its an obscure simpsons quote from the episode where Kang and Kodos run for president.
But its not that I am that much of a Simpsons fan. It truly is because the quote amuses me, just as the movie Zardoz provided me with a somewhat cool sounding alias to use.
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