detecting that a vehicle has been touched. - Page 1
Forum section: electronics / beginners

author: Simon
author_rank: Unknown
timestamp: June 07, 2013, 03:11:16 pm
content: Flowing my previous topic about people meddling with my car and wanting a deterrent I am still suspicious, Changed the oil today and the sump plug was loose if not part undone, never happened before. I also have a nail in the back tire on the offending side of the car the MOT test told me. So plan is that I'll set up a light in the car so that anyone touching it will set it off.I can preferably use some sort of touch sense or have to resort to pir sensors.Anyone any idea on how to achieve the touch method ? I assume that it's a capacitive measurement ? Once again the problem of needing to use the physical ground as "earth" for sensing a common side for vehicle and "toucher" (scumbag)

author: croberts
author_rank: Regular Contributor
timestamp: June 07, 2013, 04:08:57 pm
content: Hello SimonI don't know if it will help with your car application but I've attached a schematic, pcb and parts list for the touch switch I use in my LED lighting system. Maybe you can substitute the car for the pcb circle area.

author: SeanB
author_rank: Super Contributor
timestamp: June 07, 2013, 05:46:51 pm
content: You can consider a capacitive transducer that uses the car body, with a single insulated chain to provide the ground reference. otherwise the PIR detectors will work as well.

author: Simon
author_rank: Unknown
timestamp: June 07, 2013, 05:58:57 pm
content: what do you mean by insulating chain ?The PIR sensors will be a pain in the ass so I'd rather opt for capacitive if i can

author: lemmegraphdat
author_rank: Frequent Contributor
timestamp: June 07, 2013, 09:33:46 pm
content: You need a camera pointed at the car.

author: Simon
author_rank: Unknown
timestamp: June 07, 2013, 09:46:29 pm
content: Well they are cowards so the risk of being discovered will curtail them. They only do stuff to the side of the car that is obscured. if a whopping light goes off in the car illuminating it and the surrounding area the cowards won't want to stick around. If they persist in touching the car I'll make the horn go off.

author: c4757p
author_rank: Super Contributor
timestamp: June 07, 2013, 10:02:44 pm
content: They'll learn and figure it out and it will become an endless game of cat-and-mouse. You need something that results in discovering their identity and reporting the bastards to the police, not something that entices them to play a game of "how do I screw with his car without him knowing?".

author: Psi
author_rank: Super Contributor
timestamp: June 08, 2013, 01:30:15 am
content: I don't remember the magazine or any details but i'm sure there was a circuit in a magazine many many years ago for detecting if someone touched your car by measuring the car to ground capacitance/inductance and monitoring for a sudden change.I have no idea how well it worked though.This could have been 20+ years ago

author: David_AVD
author_rank: Super Contributor
timestamp: June 08, 2013, 01:33:20 am
content: Have you tried hiding in the bushes with a Jason mask and chainsaw?

author: Legit-Design
author_rank: Frequent Contributor
timestamp: June 08, 2013, 04:04:46 am
content: Quote from: Simon on June 07, 2013, 09:46:29 pmI bet they cannot see in the infrared spectrum, put some infrared leds and modified webcam if you can't get anything else. Webcam+infrared+motion detection with software. Unless those cowards are using nightvision or their cellphone cameras to check the surroundings. Also you didn't make it clear did you want to catch them, or see if the car has been tampered with, or just to scare them off?However I can find perfectly reasonable explanations for loose sump plug and nail in a tire. Unless you didn't drive on the road at all, those kinds of things happen all the time.

author: Falcon69
author_rank: Super Contributor
timestamp: June 08, 2013, 05:25:46 am
content: I hate thiefs.I wish it was legal to just supply a crap load of volts to the ground plane of the car, then that way, when they touch it, they instantly vaporize and kill those suckers.As said by the previous poster, there's no way to stop them. The best way is to get a garage. Other than that, any type of an alarm type system will just make them want to do it more, just to see if they can do it while bypassing your security measures.You can always shoot them, pull them into your house, and say you were afraid of your life when you heard a noise and found them creeping around inside your house.Thiefs and vandals suck.

author: Simon
author_rank: Unknown
timestamp: June 08, 2013, 07:27:54 am
content: So far it seems they are trying to do things out of idleness and think it is clever lossen things that will fall off later. Yes sump plug could be a coincidence, nail too and I'm willing to accept either but added to the loosening of a tire valve and theft (after much tampering with) of a window wiper I can't call them all accidents. All these things happen down the same side of the car, sump plugs have never come loose on me and I do my own oil changes.So what ever they do takes time as they are trying to sabotage the car so if they are seen doing it (on an estate that is regularly getting pass throughs by police) they will be less likely to try. All of the problems I've had have been down the same side of the car where it is dark and can't be seen from the road.

author: kolbep
author_rank: Frequent Contributor
timestamp: June 08, 2013, 07:36:51 am
content: Electric fence energiser in the boot. Hook one end to chassis, and just have a Bare Wire hanging Out under The Car And Touching The Ground for The Other End Of The Eht. But Run It off Its Own Battery So That You do Not Zap Your Cars Ecu.

author: Unknown
author_rank: Unknown
timestamp: June 08, 2013, 08:00:55 am
content: It's a shame you couldn't wire it up to a bird scarer, the unecpected bang those things make would make them crap for a week continuously , and let you know theirs some own messing around, give them a base ball bat welcome and job done, I'll think they'd get the message.

author: notsob
author_rank: Frequent Contributor
timestamp: June 08, 2013, 09:00:42 am
content: Yeah, the dude with the exploding car door handle thief deterrent could never get anyone to take it up

author: Simon
author_rank: Unknown
timestamp: June 08, 2013, 09:07:56 am
content: Not something you'd want to forget to disable

author: amyk
author_rank: Super Contributor
timestamp: June 08, 2013, 12:56:27 pm
content: Quote from: wilfred on June 07, 2013, 11:21:32 pmAnd rain, stray static charge (if the weather is dry) and other atmospheric effects... having it too sensitive is just as bad.

author: 4to20Milliamps
author_rank: Regular Contributor
timestamp: June 08, 2013, 01:50:47 pm
content: There are some commercial proximity detectors available, I suppose they work on the same principle as this circuit:http://www.next.gr/sens-detectors/rf-radiation/microwave-motion-detector-circuit-l14830.htmlhttp://www.viper.com/P-508D/Invisibeam%C2%AE-Field-Disturbance-Sensor

author: Falcon69
author_rank: Super Contributor
timestamp: June 08, 2013, 08:45:59 pm
content: Quote from: Simon on June 08, 2013, 07:27:54 amYou need to try and get this resolved. It could quickly turn into something verious dangerous, causing death or serious injury. For instance, if they loosen a zert fitting on a brake caliper or loosen the brake line. You won't notice it, until you try and get off the freeway doing 70mph and you have no brakes. I'd set-up a video camera somewhere outside the car aimed at the car to try and find out who is doing it. Then take the video tape to the authorities. It might just be fun and games and mischief for who's doing it, but it could become very dangerous.

author: Nitrous
author_rank: Newbie
timestamp: September 12, 2024, 06:13:20 pm
content: Hey folks, for what it’s worth, I have 3 high definition CCTV recordings of these arseho*es stealing our Lexus SUV. THE 3rd time (we installed an IGLA canbus immobilizer) they pop’ed the rear passenger window with a set punch and tore the glove box out to access the ECU. With the VIN and an ECU programmer, they overrode the factor security system and started the car but as soon as they put it in gear, the engine died.These people (including the police) couldn’t care less about video recordings. Their techniques are not propriety. 😂 my other car was parked behind the Lexus so it’s a good thing they couldn’t drive it away. The police told us smashing their way out of a blocking car is no problems. They stayed working at it for a good 5 minutes while the neighborhood listened to a very loud factory horn blaring.I’d like to discourage them from punching out the window in the first place. So, a proximity detector that triggers an interior light and/or horn to startle them.Any suggestions folks?ThanksFrustrated in Ontario

author: Xena E
author_rank: Frequent Contributor
timestamp: September 12, 2024, 10:08:41 pm
content: Get a Glock.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: September 12, 2024, 10:54:51 pm
content: There are many commercial solutions out there. The ones that I am aware of use either capacitance sensing or accelerometer for touch, or some variation of q-killing or field sensing (ala Theremin) to do proximity sensing. They all seem to have a horrible problem with false alarms, and perhaps with false negatives also.That horrible false alarm rate is why you never see anyone responding to a blaring car alarm. After all of the alarms set off by someone touching the wrong button on their key fob (and not knowing how to disarm it) and wind gusts, animals, passing pedestrians and other non-threatening activities setting off the alarm I don't pay any attention anymore, and I see little evidence that anyone else does.Given that really pessimistic view of the possibilities, I think your only hope is a non-lethal discouragement system, or something that actively involves you for threat evaluation on an alarm trigger. Something that might work on the non-lethal side is something you can buy in my area that uses a PIR sensor and triggers a water sprinkler to run for a few minutes covering the area. Loading the sprayer with butyl mercaptan or similar odorant might be interesting. Cameras are the easiest thing I can think of to get you involved. At least you don't have to leave the house to check out alerts. If you record the video you may be able to determine a pattern to their activities which could lead to better deterrents.

author: Andy Chee
author_rank: Super Contributor
timestamp: September 12, 2024, 11:33:27 pm
content: Is your car parked on the side of a public street? or is it parked in a private driveway?I might strategise in fortifying the latter.The use of IR laser beam break sensors would allow a more precise intrusion area than PIR sensors, but might be impractical to align and conceal.

author: Psi
author_rank: Super Contributor
timestamp: September 14, 2024, 03:37:56 am
content: Cats touching your car would also probably set off a touch based system.Motion cameras were you can setup the exact area of the image to detect motion in is the easiest solution.It allows you to remove areas of false trigger, and set an amount of movement required to trip, so it doesn't go off for animals.

author: JustMeHere
author_rank: Frequent Contributor
timestamp: September 14, 2024, 06:47:18 am
content: Yeah, call up Ring.....In the USA we used to have car alarms that went off to touch. The thieves would wait until a rainy day. They would set the alarm off intentionally. Then wait for you to reset it. They'd set it off again...and again...and again...until you got tired of it and disabled the alarm.A motion detect camera is the best option. You also get evidence.

author: coromonadalix
author_rank: Super Contributor
timestamp: September 14, 2024, 01:06:57 pm
content: there was some alarm systems in canada like this. but the biggest problem was sensitivity, they started for almost nothing and everything, rain wind anything touching the car, nearby vehicule(s) making dust etc ...not to be confused with movement detectors, witch too was a pain in the @#$@in the end it annoy everyone around your car, i myself don't react to this anymore, get yourself cameras or find a closed garage sorryoil plug could be your last car service done by a goon ... happened to me the plug came off by hand, i was madfor anything else in the tire could be simply hazard, i had a 1/2 drill bit in my tire once ... how ?? absolutely dont knownot bashing on your problems BUT keep in my the neighbours who can complain ... and give you more problems

author: KE5FX
author_rank: Super Contributor
timestamp: September 14, 2024, 08:53:34 pm
content: Quote from: Simon on June 07, 2013, 03:11:16 pmDude, nobody is messing with your oil drain plug. Check for a CO leak.If that's not the problem, find another oil-change place where they know what they're doing.

author: coppice
author_rank: Super Contributor
timestamp: September 14, 2024, 09:14:06 pm
content: Quote from: KE5FX on September 14, 2024, 08:53:34 pmWhy do you think that? Nails wedged against tyres, so they puncture as you move off, loosening of key accessible parts like a drain plug, etc. are the classic activities of UK yobs.

author: KE5FX
author_rank: Super Contributor
timestamp: September 14, 2024, 09:40:34 pm
content: Quote from: coppice on September 14, 2024, 09:14:06 pmHe said he found a nail in his tire, not that someone had propped one up. If I suspected foul play every time I had to patch a tire, I'd never leave the house.Around here, if someone has access to your car's undercarriage, they won't screw with the drain plug, they'll Sawzall your cat. Maybe our prestoopniks are just more profit-oriented...

author: johansen
author_rank: Super Contributor
timestamp: September 14, 2024, 11:08:46 pm
content: High voltage generator and a wire dangling off of it to charge your car up to 20kv or so.When they get zapped just claim your special tires self generate static electricity

author: Rick Law
author_rank: Super Contributor
timestamp: September 14, 2024, 11:31:06 pm
content: I've been using PIR (via Arduino NANO) to trigger exterior lights, an alarm, and to trigger photo saving on an exterior pointing camera that snap still shots every 4 seconds, normally discarded unless PIR is triggered. It work very well with cats up to 15-20 feet for over a decade. But you are dealing with something a lot heavier than just "is it a cat or what?"If someone is sabotaging your car such as messing with your pump or nails near the tires, the best way to handle that is calling the police. That leads to evidence:the best is probably video. Imagine trying to explain your PIR or Sonic distance sensor log to the police, or to jurors in court...Video will also show you directly whether it is a cat, someone walking the dog, or even perhaps a rat visiting your car to chew on the tasty wire insulation. With a video of what is visiting, you can choose the best next-step.Avoid any drastic. You could be held liable to the damage it did to the saboteur."I was just walking pass the looking for my dog and I got knock to the ground... Now my teeth is broken and I want to press charges...", worst yet, "Sir, you are under arrest for manslaughter -- John Doe slumping over your car is dead with a heart attack after your car gave him an electrical shock... he told his wife, now his widow, he was merely out to look for the dog..."This is a real case:A 77-year-old man has been charged with manslaughter in the death of a neighbor who died when she tried to free one of her pet dogs from the man's electrified fence. The police said James J. Kahl had failed to install a regulator that would have sent a pulsating current through the wire instead of a steady flow of 110 volts that killed his neighbor, Bertha A. Brittingham, 73, on Tuesday. He is free on his own recognizance pending a court hearing.https://www.nytimes.com/1988/05/16/us/electric-fence-kills-woman.html

author: coppice
author_rank: Super Contributor
timestamp: September 16, 2024, 10:35:03 am
content: Quote from: KE5FX on September 14, 2024, 09:40:34 pmIn the UK a lot of punctures are due to this kind of vandalism. The use of a sawzall for car attacks is usually limited to removing the catalytic converter, so its more commercially oriented vandalism.

author: MrAl
author_rank: Super Contributor
timestamp: September 16, 2024, 11:17:21 am
content: Quote from: Simon on June 07, 2013, 03:11:16 pmHi,I would go with the camera setup, either infra red or even visible light, if you have the car in such a position where you have a good place to mount the camera. The actual security cams are much better than web cams because web cams stop working sometimes for almost no reason. If not anything else though a web cam will work for a while and maybe if you get a good one it will work all the time, but you'll also need a dedicated computer for that running 24/7. The security cams of today have exceptional detail too, and can detect motion, or you can just let it run constantly and only check it if you see something has been tampered with.If nothing else, perhaps a light in the car can come on randomly and that way they will never know when it might turn on again.I've had my fair share of this kind of thing so I know exactly where you are coming from.An extreme example was one of my front side lights was replaced with a different color lens. No kidding. The car had orange side lights on both sides, then one day it had orange on one side and clear on the other side, and I have before and after photographs to prove it. That was just nuts. It may have been one of the garages that it was serviced in, but they never said a word.They also have cameras now that can work in very low light so you may not even need an IR illuminator with that kind. The regular security lights come with a set of IR LED's mounted right on the front of the camera so you don't have to get a separate IR source.The security systems are exceptional too. They store the video on a hard drive. They have all kinds of alarms too even audio as well as visual. if something is detected, the video starts recording onto the hard drive. A 1TB hard drive lasts a long time too, several months, and then you can just record over it when nothing has gone wrong with the car.The best bet is to go covert on this though so you can catch who is doing this and have evidence on hard drive or tape. A hidden camera is best so they do not know the car is being monitored all the time. If they find out it is being monitored, they may find another way to cause damage, and it would become that much harder to stop them in the future.What else would be cool to set up would be a dummy camera pointed in the wrong direction while the hidden camera catches everything. For example, one of those rotating cameras that rotate back and forth maybe 180 degrees. When it happens to point in the other direction, they may be tempted to try to fool the camera, thus getting caught red handed. This should probably be a last resort though because it may just scare them into doing something else.One of my neighbors got their wallet stolen out of the car in the driveway. Why they left it in there I have no idea.Another neighbor had someone scratch the whole side of his car with probably a key. Right down the whole length of the car. That's nasty.Good luck.

author: radiolistener
author_rank: Super Contributor
timestamp: September 17, 2024, 04:29:51 am
content: Quote from: Simon on June 07, 2013, 03:11:16 pmIt won't help. If they want to stole something from your car, or your car, it will take for about 5-10 seconds and light, loud alarm or camera cannot stop it.But if you want to scare off the neighbor's cat that plans to nap on your car's hood, a loud siren will do just fine.It will be more difficult with dogs that want to pee on your car's wheel, as a shock sensor won't help here. You'll need a capacitive sensor, which will frequently trigger false alarms.But all these loud car's alarms are quite annoying. For example, here they constantly triggering during the city's bomb shelling, and their wailing makes it hard to sleep at night...