🚗 Maze‑Solving Autonomous Robot

An autonomous maze‑navigation robot built using an Arduino‑compatible microcontroller, ultrasonic distance sensing, servo‑based directional scanning, and L293D‑driven differential motors. This project demonstrates real‑time obstacle detection, adaptive motion control, and a full Left‑Hand Rule maze‑solving algorithm.

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🚀 Demo

🔧 Robot (AI-enhanced, background removed)

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🧩 Features

• 🔍 180° servo‑based environmental scanning (front, left, right distances)
• 📡 Ultrasonic obstacle detection with adaptive thresholds
• 🤖 Left‑Hand Rule maze‑solving algorithm
• 🔄 Real‑time motion control (forward, pivot left, pivot right, reverse)
• ⚙️ Differential motor driving using L293D
• 🧭 Dead‑end detection and escape logic
• 🔌 Fully autonomous operation with no external input

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🛠️ Tech Stack

Category	Technologies / Components
Programming	Arduino C / C++
Microcontroller	AVR‑Based Board (ATMega32 / Arduino)
Sensors	HC‑SR04 Ultrasonic Sensor
Actuators	Servo Motor (Angle Scanning), DC Motors
Motor Driver	L293D H‑Bridge
Logic Algorithm	Left‑Hand Rule Autonomous Navigation

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🧠 How It Works

1. Directional Scanning

The robot rotates a servo from 0° → 180°, capturing distances at key angles:

• 0° → Right side
• 80° → Front
• 170° → Left

Each reading is obtained using ultrasonic echo timing and converted to centimeters.

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2. Decision‑Making Algorithm (Left‑Hand Rule)

Based on three measurements:

• front_distance
• left_distance
• right_distance

The robot selects movement:

Situation	Behavior
All paths open	Turn left and move forward
T‑junction	Prefer left turn
Right turn only	Turn right
Left turn only	Turn left
Straight available	Move forward
Dead end	Rotate 180° (pivot right twice)

This logic is implemented in the decide() function.

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3. Motion Control

Four primary movement functions:

• move_Forward()
• move_Backward()
• move_Left() (pivot)
• move_Right() (pivot)

All controlled via L293D motor driver outputs.

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🧾 Example Behavior

When the robot detects:

• Front: 12 cm
• Left: 40 cm
• Right: 15 cm

It interprets:

• Left is clear → turn left
• Move forward until front distance ≤ threshold (~20 cm)

The servo keeps the robot centered by continuously re‑scanning after turns.

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👨‍💻 About the Author

Mohammad Alaei AI Researcher & Computer Engineer 🔗 https://alaeimo.ir

This project integrates robotics, control systems, real‑time sensing, and autonomous navigation, demonstrating algorithmic thinking, embedded programming, and hardware‑software integration.