BEAKERBOT - An Autonomous Mobile Robot

Engineered an autonomous robot that extracts a ping pong ball from a 600mm deep glass beaker without exceeding 150mm height constraints. Instead of building complexity with telescoping arms and depth sensors, I eliminated it by using a gravity-assisted beaker tilting mechanism that achieves 100% repeatability through fundamental physics. 

1. Designed a complete mechanical system in CAD with a differential drive platform, a servo-actuated rack-and-pinion gripper (77N grip force, <50kPa glass-safe pressure), and a geared stepper rotation system. 

2. Implemented Raspberry Pi control coordinating brushless hub motors with integrated Hall sensors (±1mm positioning), dual-camera vision system, and ultrasonic edge detection. 

3. Validated all force calculations (1.92 N·m tilt torque for 1.06kg beaker), achieved 4.98kg total mass with strategic weight distribution (38mm tip-over margin), and demonstrated 38-second autonomous task execution.

Key Innovation: Replaced complex ball manipulation with simple beaker orientation—gravity does the work, eliminating sensors and probabilistic failures.

Critical Calculations:

• Tilt angle: 60° (vs 45.6° critical angle = 24% safety margin)

• Dynamic CG: 162mm from front within 200mm wheelbase → 38mm tip-over margin

• Glass contact pressure: <50kPa (safe for beaker manipulation)

• Weight budget: 4,979g across 12 subsystems (21g under 5kg limit)

Design Validation:

• ±1mm positioning accuracy via Hall sensor odometry

• Physics-guaranteed ball release (deterministic, not probabilistic)

• 280×200×120mm footprint (all constraints met with margin)

Project Report  -