4 min read
Marble Maze-Solving Robot

Marble Maze-Solving Robot is a final-year capstone project designed and built at Monash University by a team of three engineering students over two semesters. The goal: create a robot that could autonomously solve physical marble mazes โ€” and beat humans at their own game.


๐ŸŽฏ Project Overview

Inspired by the classic handheld maze game, this project transformed spatial reasoning and motor coordination into a robotics challenge. The final product combines:

  • ๐Ÿ” Real-time machine vision using a Raspberry Pi camera
  • ๐Ÿค– 3-DOF Stewart platform with Dynamixel AX-12A servo control
  • ๐Ÿ“ก Embedded control via PSoC interfacing
  • ๐Ÿงญ A* pathfinding with robust ball tracking and PID movement logic
  • ๐ŸŽฎ Manual vs. Autonomous play modes with a touchscreen interface

Users can either manually guide the marble or compete against the robot in a timed challenge. A built-in leaderboard displays the fastest solves โ€” with the robot outperforming human participants in 80% of trials.

๐Ÿ“„ Read the full final report:

View Report on Google Drive

๐Ÿ–ผ๏ธ Project Poster:

Poster Thumbnail
Click to view full resolution poster.


๐Ÿ›  Technical Highlights

FeatureDescription
Control SystemPID-based servo control with 12-direction tilt interpolation
VisionRGB masking for ball and marker tracking with real-time camera feed
Platform3-leg triangular Stewart platform with interchangeable mazes
UITouchscreen GUI built in Glade/GTK for selecting modes and viewing results
PathfindingOptimized A* algorithm using skeletonization for computational speed
HardwareRaspberry Pi 4, PSoC 5LP, Dynamixel AX-12A, MCP3008 ADC, 2-axis joystick

๐Ÿงฉ How It Works

๐Ÿง  Vision + Path Planning

A top-mounted Raspberry Pi Camera detects the marble and maze endpoints using colour-coded stickers. The robot uses an A* pathfinding algorithm to compute the optimal route and adjusts dynamically if it goes off-course.

๐Ÿค– Movement & Control

The platform can tilt in 360ยฐ using a 3-servo triangular layout. Movements are calculated using interpolated PID control to adjust the marbleโ€™s speed and trajectory. The robot handles corners, avoids walls, and corrects errors using techniques like:

  • Jitter correction if stuck
  • Waypoint lookahead to skip past overshoots
  • Speed scaling at turns to prevent collisions

๐ŸŽฎ Human vs Robot

Users can toggle between modes using the touchscreen. In manual mode, a 2-axis joystick provides real-time control. The screen updates with timers and saves performance to a leaderboard โ€” directly comparing the robotโ€™s solution with the humanโ€™s.


๐Ÿ“ˆ Results

In real-world trials with 10 participants on Maze 1:

  • ๐Ÿง  Robot avg. time: 43.77s
  • ๐Ÿงโ€โ™‚๏ธ Human avg. time: 59.96s
  • ๐Ÿ† Robot won 80% of the time

The robotโ€™s precise control and vision system led to significantly faster and more reliable performance โ€” even in complex, curved maze layouts.


๐ŸŒฑ Impact & Education

More than a technical build, this robot serves as an interactive STEM education tool, introducing students and the public to:

  • Robotics & control theory
  • Real-time image processing
  • Embedded systems integration
  • Engineering project management

The robot has been showcased in demonstrations and poster competitions, sparking interest and engagement among peers and educators.


๐Ÿ”„ Future Work

Planned enhancements include:

  • Automatic ball reloading
  • Maze holes and fail conditions
  • Integration of neural networks for adaptive solving
  • Enclosed camera system for improved calibration

๐Ÿงช Development Timeline

๐Ÿ—“๏ธ Semester 1

  • Research and simulation
  • Motion modeling & early prototyping

๐Ÿ—“๏ธ Semester 2

  • Full system integration
  • Machine vision and GUI development
  • Testing and user trials

๐Ÿ‘ฅ Team & Acknowledgements

Developers: Travis Barton, Chansophorn Panha In, Mark Jakubowicz
Supervisor: Michael Zenere
Unit: ENG4702 โ€“ Final Year Project

Special thanks to the Design & Build Studios and Robogals for ongoing support and educational outreach.


๐Ÿ“„ Full Report:

๐Ÿ—‚๏ธ Final Report (Google Drive)

๐Ÿ–ผ๏ธ High-resolution Poster