1. ECE 492 - Computer Engineering Design Project
Automated Tilting Ball-Maze Using Live Image Processing and Pathfinding
Jacob Charlebois, Andrea McIntosh, David Ross, Dominic Trottier
2017
Introduction
The goal of our project was to create a system to autonomously solve a tilting ball maze using image processing, pathfinding, and servo motor control.
Step 1: Initial Image
Step 2: Identify start, end and play space
Step 3: Find path
For colour ideas, University Visual Identity Guidelines can be found here:
Software Design
Initial Processing
Server gets image of maze from camera
Image processing creates a graph representing the start, end, and maze surface using colour thresholds
Graph used to compute path using Breadth-First Search
Control Loop
Camera takes an image of the maze and finds the current ball position
Based on path and ball position server determines next servo instruction and sends it to the DE2 board
DE2 board controls two servos using signal pulse widths to tilt maze in correct direction to move ball along path
Data Rates
Serial communication at a rate of baud
PWM pulses in the range 0.5ms to 2.5ms
30FPS camera operating at latency of ~35ms
Schematic of system
Hardware Components
Pre-built tilting base with a custom maze surface.
A camera mounted above the maze
Servo motor attached to the knobs are used to tilt the maze
Server connects to the camera via USB
Server connects to DE2 board via serial to control servos
System mounted on frame built by machine shop
Software Components
Image processing libraries OpenCV and NumPy
GUI built with Tkinter
Department of Electrical & Computer Engineering