Automatic Paintball defence turret for Base Defence scenarios

Hi

I have been asked by a friend who runs a small paint ball site if I could design an automatic paintball turret for base defence.

I have the turret done and can be controlled via a remote control which is a great first step, at the moment a designated player controls the turret from a protected location, this has added a great deal of strategy to the base defence scenario as the opposing team has to be able to either take out the turret or the player controlling it. The turret also has a small sensor pad that if hit (I may have to redesign this as its just using a switch that the spring pad hits when struck with a paintball, but I think the shock may eventually damage the switch), deactivates the turret for that game.

The turret can also be fitted with whatever weapon of choice for a given scenario, the weapon is mounted to the turret and I have a small actuator that pulls the trigger.

Now for stage 2 and something that is above my learning curve is making the turret fully automatic.

Is there an easy way for target identification and tracking.

I have had a few thoughts.

  1. Image based system - Each team wears a different coloured uniform and the turret tracks this colour and has some way to determine the range to target and then fires once a target has come into its firing range.

The issues with this is lots of players like to come dressed in there own camo and don't want to wear coloured uniforms, I did think about a coloured arm band or some form of coloured identification tag on the front and back of player but thought this would be too easy to hide.

  1. RFID - Each player has an RFID token that they carry with them, the turret tracks the tokens and fires at the coordinates of the RFID tag when it comes into the turrets range.

Again this would be easy for the players to cheat by not carrying the token during the game.

Anyone any advice or experience with this, all suggestions welcome.

Cheers

Druid

1druid1:
2) RFID - Each player has an RFID token that they carry with them, the turret tracks the tokens and fires at the coordinates of the RFID tag when it comes into the turrets range.

How do you get the co-ordinates of a RFID tag ?

  1. A 360o array of appropriately narrow field PIR sensors - won't handle target height well, could maybe fire multiple paintballs at different heights to compensate.
  2. A vertical strip of PIRs optimized for different heights which rotates round the turrent - no idea how well moving PIRs would work, but it would definitely look funky (+LEDs etc) and be an interesting Achilles heel (maybe a push button on turret to press to disable it).
  3. Panasonic GridEYE, though for targets more than 6-7m away it may get tricky.

In any case, you need to be sure that no animals or pets can wander into the firing zone, since they won't be wearing any protection.

PS: Since you have the turrent done, post pics of it. How it is constructed may influence what solution is most appropriate.

@srnet Sorry the RFID tags I was looking at had embedded GPS in them.

As I say don't have much experience in these systems and if they would work at all.

@arduarn Thanks for the reply's. I ruled out those options as the turrets wouldn't be able to distinguish friend or foe or animals, also the PIR sensors would probably get taken out while trying to disable the turret. Same issue I have with an image based identification system.

Like you mentioned the most important factor is not firing on things that are not meant to be shot at, so it needs a friend or foe identifier.

@srnet Just looked more into RFID tags, the tags themselves can give a distance reading back to the RFID reader with an accuracy of a few centimetres, maybe those might just work, only issue could be direction of target.

1druid1:
@srnet Just looked more into RFID tags, the tags themselves can give a distance reading back to the RFID reader with an accuracy of a few centimetres, maybe those might just work, only issue could be direction of target.

Which RFID tags, provide a link. Will the GPS be updated quickly enough to be used for target tracking?

Ignoring the RFID stuff for a second, I would have thought that inverting the logic may make more sense: so possession of the correct token allows you to pass by the turret, no token == foe. No incentive not to carry the token then.

@arduarn The RFID tags don't use GPS unless they have an embedded GPS tracker.

Active RFID readers can all report the distance of there tags using its Broadcast signal, it determines its range by the time it takes for the receiver to get a reply from the RFID tag. (according to a google search)

Yes I agree but then we still have the issue of the turret firing on anything that doesn't posses the tag, which could lead to potential wildlife issues :slight_smile:

Dunno, came across this, but looks proprietary, expensive and probably not available to the hobby maker: Quuppa. That said, there may be finished implementations which could be integrated. You could try emailing them.

PS: Check out their comparison page too.

1druid1:
Active RFID readers can all report the distance of there tags using its Broadcast signal, it determines its range by the time it takes for the receiver to get a reply from the RFID tag. (according to a google search)

Can you provide us with a link to the RFID tags (and receiver) that can use time of flight to calculate distance ?

Hi @srnet

The information comes from this post

I think I may just say that the remote controlled turret is the best solution due to the issues of trying to get a proper tracking and identification system seems to be very hard to achieve.

1druid1:
Hi @srnet

The information comes from this post

Calculate distance to RFID tag? - Stack Overflow

Which as far as I can see only says 'its possible'.

I was aware that it was possible, its being used in some WiFi applications for instance, but I have not seen any practical implementations with RFID tags.