Design Specifications

 Initial Phase

Our initial design for Ball-E included:

  1. Two Transparent Perplex Hemispheres
  2. Yellow part: Front Facing Camera
  3. Two Li-Po Batteries
  4. Two DC Motors to drive Ball-E forward
  5. Four Stepper Motors to rotate the direction Ball-E is facing for directional change
  6. 3D-printed body to house and connect the various components

However, our initial design posed a challenge with regards to precise component fitting. Even a slight deviation in size could potentially disrupt the contact between the wheels and the interior walls of the sphere. Given that we sourced components from online stores, where variations in actual part sizes were inevitable, we recognized the need to enhance the design and reduce our dependence on such high precision.

 

 

Prototype

Our prototype for Ball-E included:

  1. Two Transparent Perplex Hemispheres (20cm diameter)
  2. Front Facing Camera
  3. One 2200 mAH Shang Yi Batteries
  4. Two RS550 DC Motors to drive Ball-E forward
  5. Two Nema 17 Stepper Motors to rotate the direction Ball-E is facing for directional change
  6. 3D-printed body to house and connect the various components
  7. NVIDIA Jetson Nano 4GB

Upon assembling Ball-E, we realised that the 20cm diameter sphere was too small to fit the components within, partly because the parts we bought were not the exact size as specified by the seller, and the weights attachd to the two Nema 17 Stepper Motors were too large to fit in the sphere. Additionally, the actual weight of the sphere was greater than the estimated weight, and the two RS550 DC Motors were unable to provide enough torque for the sphere to move off from rest.

 

Final Product

Assembled Sphere

 

Our final product for Ball-E included:

  1. Two Transparent polycarbonate hemispheres (25 cm diameter)
  2. 8MP Camera for Jetson Nano
  3. One 2200 mAH Shang Yi Batteries
  4. Two JGA25-370 DC Motors to drive Ball-E forward
  5. Two Nema 17 Stepper Motors to rotate the direction Ball-E is facing for directional change
  6. 400 g brass weights to tilt the sphere
  7. 3D-printed body to house and connect the various components
  8. NVIDIA Jetson Nano 4GB
  9. Two  Arduino Nanos
  10. Four Status LEDs
  11. Three Motor Drivers (2 stepper + 1 DC)
  12. Two  ESP32 Wifi development boards (Master + Slave)
  13. Dual Mode Intel Ac8265 Wireless
  14. On/Off Switch
  15. Two  DC Motor Couplers + 2 Stepper Motor Couplers
  16. Tilt Mass Compensator
  17. Digital to Analog Converter
  18. ESP Slave (Wifi)

The completed product featured 2 different piloting modes, joystick control and AI self-piloting. Additionally, the AI algorithm that was trained to identify objects could assist the human operator in recognizing hazards. Finally the completed product had the following specifications:

  1. Maximum torque of 4.7 Nm
  2. Total weight of 2.92 kg, 12.5 cm radius
  3. 18° tilt, 40 cm turn radius (theoretical), 55 cm turn radius (experimental)
  4. 30 min battery lifespan at full operating capacity