🤖 Autonomous Line Follower Robot

Overview

This project presents the design and implementation of an autonomous line follower robot capable of navigating a predefined path using infrared sensing. The robot detects contrast differences between a guiding line and the surrounding surface, enabling real-time path correction through differential motor control.

The system is built around the Arduino Uno microcontroller and integrates a dual-sensor feedback mechanism with a motor driver to control four DC motors. A custom chassis was designed in Autodesk Fusion 360 and fabricated using 3D printing, ensuring a compact, robust, and modular structure.

🧰 Hardware Components

• Microcontroller: Arduino Uno
• Sensors: 2 × Infrared (IR) line tracking sensors
• Actuators: 4 × 3–6V DC motors with wheels
• Motor Driver: L298N dual H-bridge module
• Structure: Custom-designed 3D printed chassis (Fusion 360)
• Power Supply: 9V Battery pack
• Interfacing: Jumper wires and connectors

Circuit Diagram

System Architecture

The robot operates as a feedback-driven embedded system where sensing, processing, and actuation are tightly integrated.

• Control Flow: IR Sensors → Arduino Uno → L298N Motor Driver → DC Motors → Robot Motion
• The IR sensors continuously monitor the surface.
• Sensor signals are processed by the Arduino.
• Based on the input, control signals are sent to the motor driver.
• The motor driver regulates motor direction and speed to maintain alignment with the path.

System Features

• Real-time line detection and tracking
• Differential drive control for smooth navigation
• Compact and durable 3D-printed chassis design
• Scalable architecture for future enhancements (e.g., PID control, additional sensors)
• Energy-efficient and fully portable system

🔌 Hardware Integration

IR Sensors

• Left sensor output → Digital pin (e.g., D2)
• Right sensor output → Digital pin (e.g., D3)
• Power → 5V and GND

Motor Driver

• IN1, IN2 → Left motor control
• IN3, IN4 → Right motor control
• Connected to digital pins (e.g., D8–D11)

Motors to Driver

• Left motors → OUT1 & OUT2
• Right motors → OUT3 & OUT4

Power Distribution

• External battery → L298N (motor supply)
• Arduino powered via battery or USB interface

⚙️ System Operation

• The robot follows a simple yet effective control logic:
• The IR sensors detect the presence or absence of the line.
• The Arduino processes sensor inputs in real time.
• Motion decisions are made based on sensor states:
• Both sensors detect the line → Forward motion
• Left sensor loses the line → Adjust left
• Right sensor loses the line → Adjust right
• Both sensors lose the line → Stop or recovery behavior
• Control signals are sent to the motor driver.
• Motors respond accordingly to maintain path alignment.

🎥 Demonstration