Unmanned Gold Detector Vehicle

brad28b wrote:Hey gcause was this one of them drag coils you were talking about?

http://www.coiltekmanufacturing.com.au/40-20elliptical-drag.html

Yep thats the one I was thinking of. It should be a good size patch finder for the platform you are using. The other alternative is a standard 24x12 UFO coil.

You might also want to consider some form of electrical shielding at the back of your vehicle to reduce interference with the coil. The driving platform would need to have the equivalent of a faraday cage to remove the possibility of it interferring with the coil. It depends on the voltages you are going to use, if everything is low voltage i.e less than 12v interference shouldnt be that much of an issue.

The amount of interference will also depend on how long your tow cable / pole is from the vehicle. I would suggest you use at least the same length as a standard metal detector shaft i.e. about 1m in length.

I would still consider some kind of wooden or ABS plastic sled for your vehicle to tow the coil on as the coil can operate 1 to 2 inches off the ground and its much better for the coil than dragging it directly on the ground. As the coil is quite large it will penetrate to some depth anyway due to the shape and nature of the magnetic field it will be putting out. If you use a sled you could try out a range of standard coils and see how these go with it.

I would also suggest using the lowest gear you can the 3.5 km / hour as the old saying goes about swinging the coil "low and slow is the go".

Hi,

Have been working on this idea myself for a few months after my last trip out gold hunting. this is quite an involved proposition .


The audio analysis is actually not that simple to do , Also the device would have to be programmed to recover signals to get a couple of samples so as not to waste your time when recovering signals.

you would need to write scripting to handle object detection e.t.c , Although you can get most of it off the shelf how you operate the sensors with the coil behind you would be interesting.

There are a couple of good development boards which could host this level of script development (the stuff used on DIY drones). Something If i get time I might have a play with. I am talking about an automated platform.

Chatted to quite a few people about it on my last trip and they liked the sound of it. If you get it working well I think you might have a few customers!

themrburns

Hey Brad, check out this article:

http://www.minelabmods.com/joomla/index.php?option=com_content&task=view&id=29&Itemid=40

Good morning Brad,

I am not sure what kind of `footprint' weight is required to set off a landmine but it may be worth checking out. If your motorized device were not heavy enough to detonate a mine then the thought occurs that this could have real military implications. If you were under the weight that causes detonation then you might get a grant from the defence department. I imagine that there are not too many situations where mines are laid in dead flat areas like the WA desert but a grant may enable you to explore having a wide axled device along the moon buggy type of vechicle with independently shock absorbing wheels.

Yes, ideas are ten cents a dozen but you threw it out there for comment.

Yours tropically, Harry

harryopal wrote:Good morning Brad,

I am not sure what kind of `footprint' weight is required to set off a landmine but it may be worth checking out. If your motorized device were not heavy enough to detonate a mine then the thought occurs that this could have real military implications. Yours tropically, Harry

Hey Harry they already have these things, they are called "SAPPERS" not to be confused with Succkers...Heheheheh
X RAE man.
regards
Tony

Hey Brad how is that project of yours going have not heard from you for a while, I was looking forward to the next installment, my offer of help still stands
regards..
Tony

goldfather wrote:Hey Brad how is that project of yours going have not heard from you for a while, I was looking forward to the next installment, my offer of help still stands
regards..
Tony

Hi Tony

I ran into a lot of problems with the steering of the vehicle. Unlike most RC vehicles, the steering doesn't center itself automatically. If you turn, it stays turned. That is making it really difficult. I am also in the middle of selling my business so I haven't had a great deal of time to work on it. I probably won't have the time to put into it for another month or so.

All been done before mate by a guy that was a regular on Finders Forum, whose name I can't recall. The machine was like something off a Mars Lander, well made but cumbersome, mounted on a quad bike. It musta cost a fortune. When he ditched it and his lady he buggered off to Kazhakstan or some such place. I was asked did I want to try it out. I accepted and me, my wife, a mate and the lady concerned took it "North of Meeka" up near The Frenchmans Patch. After only two days with it, I was ready to walk away from the bloody thing. It was good at collecting the data and using Ozi-Explorer to map and track the signals - just as you plan to do. All good stuff - in principle. But in anything other than dead flat ground it was useless. It took ages to set up, calibrate, etc, etc. By the time it was ready to go it was damn near "stubby time". Too much trouble and PITA. Although I had great hopes, I went back to swinging a coil. There was a bit of "Personality Conflict" in the whole deal, but that's me. I'd give it 4 out of 10 as a useful tool. I think it may be on Meeka rubbish tip by now.

But that was years ago,,,,,,,,,,,,so fill yer boots anyway.

Brad, full points for tenacity, however your project is riddled with problems some of which may be insurmountable. I feel the trap you have fallen into is "technology for technology's sake". In 1987 Minelab built a prototype EMDAR (electronic metal detecting and recovery). This System used a hopper, conveyer belt, and a reject gate controlled by a metal detector beneath the belt. A timer opened the gate and reclosed as a signal passed above it seperating the material containing the signal. Systems like this are used in the food industry but EMDAR was designed to remove specimens from oversize. An EMDAR was sent from Adelaide for testing with a deep lead heap that had proved to have many overlooked nuggets of decent size as well as a lot of junk. A loader was required to load the hopper and clear the rejected material. There were a few bugs but the system worked. After a certain tonnage was put through I suggested that we push out the same amount with small crawler, hand detect it and compare the results. The EMDAR took far longer and was not as accurate as we also checked its reject pile by flattening it and hand detecting. By the way, the EMDAR cost $80,000. I don't mean to be a wet blanket, but can you see my point . Minelab was not too pleased with me, but i was just trying to save them grief. Shoot the messenger. Please don't get me wrong, I hope you pull this off as you seem most determined. ps. I don't know what happened to EMDAR.

Crikey, swing any faster and I think that thing would take off............. I am betting they used a windscreen wiper motor and mechanism for the swinging function.

Would be a great piece of equipment, just re engineer the metal detector to a manageable size and as others have said be sure to keep any metal clear of the coil. As for swinging the detector a simple cam mechanism linked to wheel movement could work. The wind screen wiper might be fast but use a speed control on it.

You could make the body of the vehicle from poly sheet and plastic weld the joints.
UHF CB has 2 data channels on 22 & 23 that you could legally use for remotely sending data packets of info to your laptop that you could then act on as required.

I wanted to put a couple of links here re: the English girl mentioned in a previous post but as I'm a new member I'm not allowed, but to get around that. (sorry) just put the usual http, www etc in front of this.

dailymotion.com/video/xjvufs_decima-machine-remote-controlled-on-radio_webcam
dailymotion.com/video/xikocp_decima-2_shortfilms
She's not the sharpest tool in the shed but she's found a lot of stuff.
I'm sure you could come up with something better than that, and I look forward to seeing it on here first.

Good luck with it.

Nice Idea Mr Spock! I wish you well,...........but next time just take one of the red ones and one of the green ones
Regards
Wayne.

What about one of these babies.....

Any update on this project?

Personally I would rather having a tow blanket behind a quad bike, and either stop for each target, or have a gps pointer like SPOT, mounted on the handlebars, when you get a beep you push the button and move on, then when you come back (possibly the next day with the amount of ground you would of covered) and with the waypoints reprogrammed into a handheld GPS, stop at each point and sweep with a normal detector until you find your target.

The beauty of using a coil blanket is that it will most proberly miss the smaller stuff and just focus on larger noteworthy nuggets possibily a bit deeper.