Stopping Cars With Microwave Radiation

Ponca City, We Love You writes "Researchers have created an electromagnetic system that can quickly bring a vehicle to a stop by sending out pulses of microwave radiation to disable the microprocessors that control the central engine functions in a car. A 200-pound unit attached to the roof of a police car can be used to stop fleeing and noncooperative vehicles. The average power emitted in a single shot is about 10 kilowatts at 100 hertz and since each radiated pulse lasts about 50 nanoseconds, the total energy output is 100 joules at a distance of 15 meters. One concern with the device is that it could cause an accident if a car is disabled and a driver loses steering control. The device could also disable other vehicles in the area so the most practical application may be for perimeter protection at remote areas. Criminals have a work-around too. Since electronic control modules were not built into most cars until 1972, the system will not work on automobiles made before that year."

Comments

What happens when...

[cuteseal]

What happens when criminals get their hands on this and start disabling police cars as well? :D

Re:What happens when...

[nocomment]

or worse, the police disable a bystanders pacemaker.

Re:What happens when...

[DirkGently]

No. Aeroplanes use entirely shielded electronics gear. Missiles (especially the nuclear type) are likely to be used in an environment with a high probability of an EMP burst and are built to withstand it (which is why "mil spec" usually equates to badass). Satellites? They contend with a helluvalot more than 100J of energy on a daily basis.

Which also makes me wonder why, if someone were intent on illegality, they couldn't put their own little faraday cage around the car's ECU. A little box made of copper with a drain wire to the car frame too hard to implement?

Re:What happens when...

[Goldenhawk]

I'm seeing a lot of comments here focusing on the overly intelligent criminal.

Problem is, MOST of the car chases you see on TV are:
1) Drunks or druggies, not in their right minds
2) Car thieves (not riding their own wheels anyway)
3) Suicide-by-cop idiots, who WANT to be killed, not stopped safely

Okay, fine, the really intelligent criminals might be able to prevent themselves from being stopped this way. Granted. But the really intelligent criminal is NOT going to find himself involved in a car chase anyway, because he's too smart to let that happen.

Frankly, I've wondered for years why they didn't do something like this. Or mount a piton system in the front of your average police cruiser, that could pneumatically or explosively shoot out a grappling hook that stabbed thru the trunk of the fleeing vehicle and drag it to a stop. Most police chases involve very close pursuit at reasonably slow speeds - so why not nail the guy's trunk and drag him to a halt, instead of trying to PITT him and risking all kinds of damage to both vehicles?

So I'm happy to finally see this kind of technology under real development.

And for those of you who are worried about innocent bystanders, remember that EMF falls off as the square of distance. Whatever power kills a car 45 feet away (100 joules) probably won't even blip an engine 450 feet away (1 joule). There will be plenty of chances in most car chases to SAFELY utilize these things.
https://answers.google.com/answers/threadview?id=409268

Grandma was found dead at the scene

[BadAnalogyGuy]

Grandma was pulled over by the sheriff
Coming home from our house Christmas eve.
Cops say microwaves can be used safely,
But as for me and Grandpa, we disbelieve.

Tinfoil

[megaditto]

Not just for hats anymore.

Faraday cage

[Nimey]

So you put a Faraday cage around the car's ECM. Problem solved?

Also, are these rays energetic enough for, say, crowd control? And what if the cops are chasing someone with a pacemaker?

Re:Faraday cage

[Dunbal]

And what if the cops are chasing someone with a pacemaker?

      Then the cops involved are suspended with pay during the official investigation, which will find that the cops could not be reasonably expected to have known that the person had a pacemaker, so they will be off the hook, AS USUAL.

Re:Faraday cage

[Technician]

No. Each wire entering into the ECM is another vector, thus inputs into the ECM would have to be protected.

Coaxial feed thru capacitors through a RF gasketed cover followed by a small RF choke and ferrite bead should do the trick.

War Zone

[elzurawka]

Seams a lot more useful in a war zone. At a roadblock in Iraq i think people would appreciate their engine getting shut off a little more the getting shot at.

It could even be set up on a speed trap so that if you enter a road block at a certain speed it would shut off the car automatically.

I guess once again the problem may lie in the fact that most cars in Iraq and other hot spots may not have the Electronic components needed for this. But hey if it stops something like http://news.bbc.co.uk/2/hi/europe/4323209.stm then i think its worth it?

Organic shield

[GaryOlson]

Shield the microprocessor with some left-over casserole. Microwaves never fully penetrate the the center of that mass.

Collateral Damage?

[AugustZephyr]

The device could also disable other vehicles in the area

So when there is a chase in a populated area, the cops will leave a wake of disabled cars? That will be fun to clean up later...

Big deal...was done in the 80's

[PortHaven]

Knight Industries K.I.T.T. 2000 was able to do just this. ;)

Nice Gadget, but What I really want

[slntnsnty]

Is a device that causes those obnoxious Bass units that shake every car for 3 blocks to implode. Now that would be a useful gadget.

Re:Nice Gadget, but What I really want

[Anonymous Coward]

Such a device would inevitably be named
"All Your Bass Are Belong to Us"

Concerns are quite valid

[AP2k]

One concern with the device is that it could cause an accident if a car is disabled and a driver loses steering control. This isnt a problem for most of the vehicles on the road today since they use primarilly hydraulically actuated power steering, but you can still steer even without hydraulic pressure. Same thing with standard rack-and-pinion and recirculating ball steering systems. For these three types, only a grandma that doesnt expect to loose hydraulic pressure will have any serious problems controlling the car.

However, steer-by-wire systems are quickly coming into play in America, especially on some of the lower-end GM products. Now I'm no GM engineer yet, but from what I gather the steering system is either on the GMLAN high speed bus or it has its own bus but still gets data off GMLAN.

Now suppose the ECM stops giving out speed information on the GMLAN bus. Hopefully there is a contingency plan in the steering logic so that you can still have some steering I/O even without the vehicle speed information, but if the output isnt on its own bus, I cant say I'd want to be in that car.

Faraday Cage won't necessarily stop this!

[compumike]

I'd like to try to explain why their microwave design might work, and why the "faraday cage" argument isn't enough: Differential vs. Common-Mode Signals. It's because of all the devices connected to the car's central engine controller.

Lots of old school communications protocols are based on single-ended signaling, where one voltage represents a 0 or 1. This includes RS232, Parallel, and even ISA and PCI slots on your motherboard. However, almost everything new that's outside the computer is based on differential signaling -- reading the differential voltage between two wires. This includes 10/100/1000BaseT ethernet over twisted pair, USB, Firewire, etc.

Here's the key difference: when you get noise coupling onto your signal, whether it's a pulse from the engine ignition coil firing or from this car-stopping microwave device, it tends to be the case that the voltage of *both* of the differential wires is increased by the same amount -- so that when the voltages are subtracted, the effect of the noise cancels out.

However, this exploits the fact that no devices have an infinitely large common-mode range. That is, the average voltage of the differential pair must be within some predefined limit, or your circuit won't work. By putting in a big enough pulse, this microwave device might be able to move charges around on the outside of the car body (which happens to be the ground that most devices hook to) enough to move the voltages significantly. This would cause any devices (think an oxygen sensor or a tachometer) to act as though they were momentarily dead.

Thus, even with differential signaling (which cars already use), it's possible to break things by putting too much common-mode noise on top. See Wikipedia article.

--
Can you code? Want to become a hardware hacker? Educational microcontroller kits for a digital generation.

microwaves are a Hazzard

[ChristTrekker]

At least the Duke boys will be safe in that '69 Charger...

Faraday Cages

[Spy der Mann]

Which also makes me wonder why, if someone were intent on illegality, they couldn't put their own little faraday cage...

Faraday Cage: Your CPU's tinfoil hat. Never leave home without it!

Re:Won't stop my 1980s car

[Spy der Mann]

HAH! I use a manual bycicle! Try EMP'ing that!

'67 AMC Rebel

[Arathon]

This is why I love my car.

Also, because the average car thief wouldn't even be able to *start* my car, much less actually drive away in it. It's hard to evade cops when the slightest mistake while sitting at a red light or going through a toll booth causes the engine to die.

Oh, and did I mention that to restart the car while moving, you have to put the transmission halfway in between Reverse and Neutral, turn the key, then quickly shift back over into Drive in case the magical transmission gnome decides that you were closer to Reverse than Neutral?

Re:'67 AMC Rebel

[jag7720]

That is why AMC is no longer making cars..... and no one but you is still driving them

Re:Won't stop my 1980s car

[Skevin]

> No electronics to kill.

That's why this microwave transmitter has a dial with the following settings:

Microprocessor Disruption (default)
Sparky Metal
Mortal Kombat Raiden

That last setting is the most noticeable. I preferred the old microwave emitter, which referred specifically to your driver:

Light
Medium
Dark ...but some police departments interpreted it to refer to the ethnicity of the offending driver, as opposed to how crispy you wanted them to be.

Solomon

My '81

[X86Daddy]

I have a vehicle built in 1981 and I know the electronics on it pretty well. The idle controller is the only part with ICs besides the modern stereo and car PC, and I believe it will simply idle rough without that controller functioning. My steering is rack and pinion, my auto transmission computer has nothing more advanced than a transistor; same for the door lock controller. Everything else is vaccum, steel cable, etc... So the date value for vehicles that are impervious to this attack can be set a little further forward.

Re:Steering?

[Dun Malg]

New luxury cars are being developed (some BMW and Mercedes - I don't know if they're being sold) that don't even have a direct connection between the steering wheel and the drive train. Instead, it's all computerized with some type of central bus system. This allows for much smoother/easier handling. So far, only BMW and Lexus have electronic steering planned, but even those are hybrid systems that maintain a direct mechanical linkage. It's not just a safety issue, but an issue of control. Whether you realize it or not, you get quite a bit of feedback about how the tires are interacting with the road through the movement of the steering wheel. Control is actually better with a direct link. This is why they do not plan to go 100% electronic.

Re:The real scoop on RFI suppression

[Technician]

I tried to be informative, but was modded funny as people just thought I was using buzzwords.

RF on a wire can be shorted directly to the case with no way past due to lead inductance when coaxial feed through capacitors are used. They work well and are used on every microwave oven made. They are on the bottom of the magnitron. The fillimant leads come from the bottom inside a box. They then go through feed through capacitors to keep microwave energy from radiating out the wire.

http://www.freepatentsonline.com/7184256.html

photos here at the bottom of the page..
http://www.samwha.co.th/capacitor.htm

RFI suppression on motors..
http://www.freepatentsonline.com/6307344.html

RFI protection for pacemakers.. PDF alert..
http://www.interferencetechnology.com/ArchivedArticles/medical/Article08web.pdf?regid=

A full filter often includes an inductor. Here is an example. PDF alert..
http://www.dearbornelectronics.com/pdf/EMIFilters.pdf
This shows performance curves of various filters. A 3 DB change is the half power point. To have the same effect on a device 3 DB less sensitive would require double the power. Many of these devices have more than 80 DB attenuation at 10 MHZ and above. This would provide a high degree of immunity as the RFI source would need to be very close and very powerful to overcome the attenuation compared to an unprotected device.

Info on ferrite beads is here...
http://www.google.com/search?hl=en&q=ferrite+bead+RFI

Unlike a capacitor or inductor, a ferrite bead doesn't re-direct the RF current. It converts it to heat, and in the process, attenuates it. A capacitor on a wire, may make a tuned antenna at some frequencies. The ferrite bead is to prevent these tuned peaks by eating the power. Used in combination with a feed-through will prevent a tuned standing wave building on the wire.

A capacitor and inductor simply make a tuned circuit with a venurable frequency. Diodes, discharge tubes, resistors, and ferrite beads prevent a high Q tuned circuit.

http://en.wikipedia.org/wiki/Q_factor

For example, a pendulum suspended from a high-quality bearing, oscillating in air, would have a high Q, while a pendulum immersed in oil would have a low one.

Forget "criminals"

[StarKruzr]

I just want to be able to take out the cop car who chases me down at speed traps.

Cop: "HAHA I'M ON UR HIGHWAYZ CLOCKIN UR CARZ!!1 OMG FIVE MILES OVAR!!!"
Me: "lol noob" *MICROWAVE-PWN*
Cop: D: WTF WALLHAX

Looking for really, really ignorant investors?

[Futurepower(R)]

He didn't fail reading comprehension. My guess and my opinion is that it is either extreme ignorance or deliberate fraud, and maybe someone at Slashdot is taking money to post articles about companies that want "investment" money.

Fraud Alert. Fraud Alert. Fraud Alert.

Read the first comment to the article: "What happens to the pacemaker in the guy driving? Does speeding become a death sentence?"

Another comment: "If there are innocent victims in such incidents - such as hostages - how are you going to microwave the car without hurting the people?"

What about reflections? Fried police car, anyone? "I just looove the smell of burning plastic in the morning"?

I think November 13 is a little early for April Fool's day.

Quote: "These pulses are amplified to 640 kilovolts..."

Did you see the red whiskery antennas that extend in front of the car? Criminal: "There's that dorky police car again. Turn right. Microwaves only go straight." Or, are those not antennas, but an artist's rendering of microwave flames shooting from the top of the police car?

From the article: "The system has been tested on a variety of stationary vehicles and could be ready for deployment in automobiles within 18 months..."

Translations: 1) It hasn't been tested in heavy traffic. 2) As soon as we find some really, really, really dumb people with money to invest, something could happen.

Moral of the story: There is no time to play video games. You need all your time to learn about the world around you, not about fantasies. If you spend all your time with fantasies, anyone can tell you anything, and you won't be able to evaluate if it is the truth.

Quote from the story: "Finally, a specially designed antenna beams the microwave energy toward an opposing vehicle through a part of the car, such as the windshield, window, grill, or spacing between the hood and main body, that is not made of metal. (Metal acts as a shield against microwave energy.)"

Ohhhhh. It must be an opposing car, not one going in the same direction. The car must have no mirror-like surfaces. There must be holes. It can't be a camper going in the same direction.

Has no one who already commented on this story heard of firewalls, the kind in cars? Has anyone heard about tight-fitting hoods? Does the invention work only with hoopties?

Is it really true that no one who reads Slashdot has looked at the insides of a car? Does this "invention" work only with cars that don't have electronics shielded with a metal covering?

Those dumb car makers never heard of electromagnetic noise? Even though spark plug wires have 40,000 volts? Car computers have no shielding?

Are they liable for other cars?

[Shivetya]

So if they are zapping someone and hit another car are they responsible if that car crashes? Will this affect on board safety equipment as well? ABS? Airbags? There is a lot of reliance on microprocessors in many new cars.

It would not be long after entering service before they hit the wrong car and the question becomes, how will the courts treat that?