Raspberry Pi Paintball Sentry Turret

For getting those peksy burglars off your property in a semi-harmless fashion

Sentry Turret

Project description: The Autonomous Paint-ball Sentry Turret is a legal defence system that can efficiently remove intruders from the owner’s property. The system uses motion detection and tracking algorithms to locate moving targets, and fires either autonomously or manually. An effective motion detection system has been developed using Python along with OpenCV on a Raspberry Pi 3 Single Board Computer that controls three servo motors (pan, tilt, trigger). Motion tracking was implemented using the periodic background estimation subtraction algorithm

Code and Full report available at: https://github.com/Dewald928/PiSentryTurret.

1. Design

A lot of the research and design is based on Project Sentry Gun I replicated the mechanical design and reconfigured the system to work with a raspberry pi such that it can be used as a standalone system.

Design

2. Implementation

I put together the hardware and the software to create a working prototype. The system uses a Raspberry Pi 3, a webcam, and three servo motors to control the turret.

Setup

3. Testing

Now... to find willing subjects. I started with rolling a car tyre to track it's speed and accuracy. But I needed more! So I got a friend to run around the yard while I tested the system. After we've acquired sufficient bruises from the piantball we could make our conclusion.

You can view the whole development process on Youtube

4. Conclusions

The turret was able to track and shoot targets, but not without flaws. Many of the mechanical failures were due to unprecise tolerances that caused gear slipping, which threw out the calibration. The software was good at tracking, but can be improved with higher quality cameras and more advanced tracking algorithms.

Is this practical? For it to be, it will need to be always-on and reliable. Here are some of the downfalls of a system like this:

  • Ammo - You're going to run out of it. A better hopper system is required, if you're going for that ultra rapid fire.
  • Maintenance - The system needs to be checked if it still has CO2 or air in the canister. So more sensors and checking required.
  • Power - The system needs to be powered on all the time. So you're going to need a UPS or a solar panel.
  • Range - The further the target, the less accurate.