ThunderBird 6 - Gold-Coin-Ring-BottleTop-Finder
@ Tue, 2009-07-28 22:22
- Actuators / output devices: Hacked A: Drive Stepper Motor
- Control method: autonomous
- CPU: 2 Arduinos - long term Arduino Mega
- Operating system: C
- Power source: 7.2V
- Sensors / input devices: Metal Detector
- Target environment: Beach - Grass - open areas
ThunderBird 6 - Gold-Coin-Ring-BottleTop-Finder
So my latest Bot project is off the ground...... or should i say able to find out whats under the ground......
Objective (primary) :- Get a bot to follow a line of coins. ie line following with a difference.
Objective (Secondary) :- To find treasure..........lots of it ...... all by it self........
Objective (Thirdary) :- Self Funding ... able to detect enough money to Fund its self.
How :- Fix a Hacked Metal detector on to a servo that scans left and right and also Up and Down.
The Up and down is a stepper motor with linear guide-rail hacked from and (old) A: drive floppy disk.
Spin Offs :- It will wander around the garden/beach Autonomously looking for gold/silver/coins etcetcetc.
The Following is a progress of the project so far , just pictures for you to drool over.........
The Hacked Metal Detector is mounted to a scanning servo which is mounted to a linear up/down stepper motor.
Code-ing for stepper motor and servo scan works fine - motor drive now working.
NextToDo:- Metal Detect Strategy
Basic Setup
Coil protected by Plastic cover
You can also see quite clearly the A: Drive Stepper motor top right
The Stepper raises and lowers the probe assembly.
The probe is fixed to a Servo so able to scan Left and Right.
The Metal Detector consists of 2 separate detetor coils wound around a ferrite rod.
The Circuit is a Beat Frequency Oscillator - able to detect metal and also live electrical cable.
The Beat-frequency oscillator (BFO) is the simplest type of metal detector.
The basic beat-frequency metal detector employs two radio frequency oscillators which are tuned near the same frequency. The first is called the search oscillator and the other is called the reference oscillator.
The outputs of the two oscillators are fed into a mixer which produces a signal that contains the sum and difference frequency components. This signal is feed to a low-pass filter removing the harmonics. As long as the two oscillators are tuned to the same frequency, the output will have no signal.
When a metallic object disturbs the magnetic field of the search coil, the frequency of the search oscillator shifts slightly and the detector will produce a signal in the audio frequency range.
@ Tue, 2009-07-28 23:40
ThunderBird 6 - Gold-Coin-Ring-BottleTop-Finder
Yes ThunderBird 6 Is off the Ground.... or should i say looking at things under the Ground.........
This project has been in the back of my mind for a while now and the time is right to bring it into Life.
Basic Idea is a free roaming Robot that will scan an area of land/beach for metal objects.
I will also program it to follow a line of coins (different twist on Line-Following bots)
(-: The ultimate goal would be for it to find its own money to pay for its own developement :-) - now that would be a challenge.
Previously Blogged Here
@ Tue, 2009-07-28 23:39
cool!
@ Tue, 2009-07-28 23:52
You will have to include the BFO circuit
You would have to include some form of Beat Frequency Oscillator circuit.
The output is a variable voltage depending on how close the coil is to the metal.
(however if you where to wave a magnet at the coils then they would give a very-small voltage output ie. without the BFO circuit connected .....not sure if this could be picked up by picaxe though - you would have to try and let us know if it works) - you can find coils similar to this in old am/fm radios
@ Wed, 2009-07-29 00:01
You don't need a beat
The coil is able to detect changes in magnetic fields that pass through it. Without some sort of drive circuit, there's nothing to produce the magnetic field that will interact with the coins, etc.
@ Wed, 2009-07-29 00:46
hmmm...
@ Wed, 2009-07-29 16:08
Just updated info on BFO
Just updated info on BFO, to give idea on how its done.(above)
It would be interesting to remove the BFO circuit and feed a drive frequency to the coils direct from an arduino/pic etc - however my guess is you would still need a few decreet components to interface the coils.....and a frazzled brain working out the software driver ....ekkkk
@ Wed, 2009-07-29 00:44
Gareth, what will it do when
Gareth, what will it do when it's found something?
Perhaps you could mount a mesh shovel behind it, so that upon detection it does a 180 deg turn, backs up and digs the mesh into the ground/sand to pull out whatever it is that it's detected...
after an attempt with the shovel, it could spin back around and suvey the hole to ensure that it got whatever it detected....?
@ Thu, 2009-07-30 00:04
Digging would be a tough job
The design of the bot is quite small - i think it would only cope with digging sand.
The idea i had was to have a tagging system.
Either by dropping a marker (flag) when it finds something..... then moving onto its next goal.....
or attaching a GPS unit to it --- this way its possible to make a form of 2D mapping.
I know GPS is not so accurate (2-3meter)- but i would be able to scan in say 3Meter cells ie make the bot do a 3 meter spiral then move onto next cell GPS 3meter cell. The scanning probe will have lots of overlap anyway - probe scans each time an area covering 300mm x 60mm.
NB. i like your mesh idea and this would work in sand . All i would have to do is lower a mesh or wide comb like thing into the ground when it detects .....carry on forwards and it would get trapped in the mesh.......
@ Wed, 2009-07-29 20:03
Uuuh!! SO very very
Uuuh!! SO very very original. Yet so simple and aahh!! What a cool toy this could be!!!
Uh, G you are topping the list!
@ Wed, 2009-07-29 21:52
Do you remember the Stepper Motor ShoutBox
I didnt forget the Stepper Motor ShoutBox.... i will document the surgical operation of the A:Drive Stepper motor shortly.
The Stepper works a dream and i have found out that interleaving the coils give the best torque for lifting the Detector.
Plan is to give it "Voice" and RF camera so i can sit in my Deck-Chair and wait (lazy mans gold washing).
@ Mon, 2009-08-03 21:36
Cool!!
@ Wed, 2009-07-29 21:53
solid mechanics, brillant
solid mechanics, brillant ideas, cool aesthetic
as usual Gareth is the best
@ Thu, 2009-07-30 11:05
The pictures look great :D
@ Thu, 2009-07-30 20:02
We have to find a way around this.
Super to hear from you ..........
We will have to find a way for you to view LMR robots....
Try this link ThunderBird 6
and tell me if it works - you may have to double click the vids........
@ Fri, 2009-07-31 12:32
Whoo Hoo!
@ Fri, 2009-07-31 13:11
Out of curiosity which video services does china allow
It may be of interest to others - which video services does China allow, or is there a backdoor somewhere ....(evil LöL).
1.5 is better than 0 - cool.... the other .5 is only a close up of the stepper anyway.....
@ Thu, 2009-07-30 12:16
As usual, a great idea for a
As usual, a great idea for a robot, Gareth. Is this an Arduino Mega board, you are using?
@ Thu, 2009-07-30 18:28
The Plan is Arduino Mega ....however...
The Plan is to use an Arduino Mega ..... however........
....... the motor and sound shields designed for the arduino do not work on the Mega :-(
....so its currently got 2 arduinos until i get the basic system working and then i can find a way to intergrate them together..
@ Fri, 2009-07-31 18:17
I2C?
@ Fri, 2009-07-31 18:42
Some_how 2 Arduinos appeal to me
The idea of serial chattering Arduinos does appeal to me.
I have dabbled with the I2C channel before (Wii) but never really understood it - so this would be the perfect chance .......
....hummmmm where to start.....
I have managed to shoe horn all the drive and sensor electronic on to one arduino - looks like the second with have exclusive attention for the voice output.
Serial link between the two would make things easier - as i only have a few spare i/o lines.
@ Fri, 2009-07-31 20:34
Wii I2C isn't a good example
@ Thu, 2009-07-30 12:20
Wow! This is the first robot
Wow! This is the first robot that finds treasures, at least that I remember of! Soon you will be a rich man!! :D This is brilliant!
Will you add some kind of a buldozer robotic arm to digg holes? :D
@ Thu, 2009-07-30 19:02
Awaiting Sponsors - for bigger version
I think poor ThunderBird 6 will need to be a bit bigger for "Autonomous Dig Mode" - it would be neat idea to have "Drone Diggers" to sweep and do the digging for him......... (at the momment the digger is Me!!!!)
I like the robotic arm idea - maybe i could strap a very powerful electromagnet to it and zap the metal direct out of the ground....
....... So if there are any Sponsors out there (JCB-Caterpillar etc) wishing to buy advertising space (albeit small) then look no further .... proceeds will go towards ThunderBird 7
@ Thu, 2009-07-30 21:27
Latest ThunderBird 6 Update - Hardware layout
So its take-ing shape now - much faster than i thought as interest is starting to spread eekkkk.
Current system is So.......
Metal Detector :- Connected to scanning left/right servo (working) which is connected to Up/Down hacked A:Drive stepper motor (working).
Sound Card interface :- Working but not interfaced to metal detector yet - its been programmed with about 15 words so far and will give verbal feedback on what it is doing and hopefully finding.
The Speech is stored on an 1G SD card which the Arduino can decode and playback. (so there is enough space for TB6 to sing a few songs too).
Autonomous mode :- scanning ultrasonic range finder installed - to be programmed.
Motors and tracks :- wired to drivers and awaiting software control
@ Thu, 2009-07-30 20:20
Ok I hate you man :P
It's always a pleasure to see your creations :D
The detector is actually a hacked radio ... right?
10 stars you get :D
@ Thu, 2009-07-30 21:20
Hacked Hand_Held Metal Detector
The sensor part on my system is from a Hacked Hand_Held Metal Detector.
These can be picked up at reasonable cost - sometimes they go as security metal detectors. (mine was originally from RS componants)
However i have seen radios hacked to detect metal but i dont know how sensitive they would be.
NB. ThunderBird 6 will be tuned to detect "Tin" but not sure if the tune-ing would reach as far as "Heads"
@ Sat, 2009-08-01 00:30
TB6 Update Tracks-Stepper-Scanner Servo-Ultrasonic Servo Working
The "Drive" Arduino has been programmed as one routine containing:-
Track Drive Motors 2 (tested fine)
Stepper Motor (tested fine)
Scanner Servo for Metal Detect probe (tested fine)
Ultrasonic Servo for object detection (tested fine)
Edit:- New Videos Posted showing forward motion with detect scanner - including voice.
The Metal-Scan Strategy has to be conjured up now.
Though i have to say i am looking forward 2 include the speech part of the program on the "Speech" arduino........
@ Sat, 2009-08-01 08:18
The voice?
Which voice synthesizer you used?
This bot looks great great with the voice!
@ Sat, 2009-08-01 23:03
Wav Shield controlled by Arduino
The voice was made with a Wav shield Attached to an Arduino.
You basically save wav files to an SD card (mines 1G memory) and slot it into the wav shield direct.
The arduino makes an index of the each wav and you can then select and playback on command - or triggered like TB6.
@ Sat, 2009-08-01 20:25
How did you get ThunderBird