README.md

Ball-Balancing-PID-System

This project consists in the realization of a Ball-Plate system with 2 degree of freedom which will control the position of the ball by tilting the plate.

• Two servomotors will allow the table to be oriented with a certain angle of inclination to counterbalance the movements of the ball.

• A Pi camera placed above the device will feed live images of the plate to a Raspberry PI 4B.

• A Python program will then be responsible for processing these images, analyzing them to draw conclusions such as the position of the ball, its speed and acceleration.

• Then it is feed to PID controller and transmitting the result by USB to the Arduino which will control the rotation of both servos independently.

• All the data will be sent to the Python program running in another computer using MQTT protocol. And the results would be plotted.

Video of Implementation

Team members:

• Amoghavarsha S G
• Niranjana Jois H C
• Kiran C N

Block Diagram

Requirements

• Hardware
  • Raspberry Pi 4B
  • Pi Camera
  • PC
  • Arduino
  • 2 Servo motors
  • Universal Joint
  • 2 Push rods
• Software
  • On both Raspberry Pi and PC
    • opencv-contrib-python
    • numpy
    • json
    • paho_mqtt
    • threading
  • On Raspberry PI
    • pyserial
    • mosquitto broker
  • On PC
    • pyqtgraph
    • Qt5

Setting up

• Raspberry pi

  • Install raspberry pi os.
  • Install mosquitto broker on your Raspberry PI.
    • sudo apt install mosquitto
  • Install all the python packages mentioned above.
  • git clone this repositiory
  • we only need on-pi directory files here

• Arduino

  • Clone this repository on PC
  • Upload the on-arduino.ino file in on-arduino directory to the Arduino.
  • By default pin 5 is for X-axis servo and 6 for Y-axis servo.

• PC

  • Go to interface-on-pc directory

  • run startInterface.sh if on linux or startInterface.bat if on windows

  • Interface Image

    

• Table

  • Table Image

    

  • Aruco Marker order (aruco.DICT_4X4_50)

    • Top left: ID 0
    • Top Right: ID 1
    • Bottom Right: ID 2
    • Bottom Left: ID 3

  • You can change the ID's or their order. If you do, then:

    • In on-pi/main.py change the list aruco_marker_order in order mentioned above.

• Servo Motors

  • Servo Placement

    

  • Distance from centre to both x and y axis servo: 8cm

• Raspberry Pi and Pi Camera

  

• Overall Structure