Arduino Based Human Following Robot

An intelligent autonomous robot that can detect, track, and follow a human target while maintaining a safe distance using an Arduino microcontroller, sensors, and motor control systems.

📋 Table of Contents

1. Background and Overview
2. System Architecture
3. Hardware Components
4. Algorithm and Implementation
5. Results and Future Scope

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1. Background and Overview

Project Objective

This project demonstrates the development of an intelligent robotic system capable of autonomously tracking and following a human target in dynamic environments. The robot combines hardware sensors, actuators, and intelligent algorithms to create a responsive human-robot interaction system.

Key Features

• Autonomous Human Detection: Uses IR sensors to detect human presence
• Distance Measurement: Ultrasonic sensor maintains a safe following distance
• Intelligent Navigation: Real-time decision making for movement control
• Obstacle Avoidance: Prevents collisions while following target
• Wireless Potential: Foundation for future remote monitoring capabilities

Applications

• Assistance Robotics: Personal assistance and mobility aid
• Surveillance Systems: Security and monitoring applications
• Interactive Installations: Entertainment and educational purposes
• Research Platform: Human-robot interaction studies
• Emergency Response: Search and rescue operations

Team Information

• Institution: RCC Institute of Information Technology
• Department: Electronics and Communication Engineering
• Supervisor: Dr. Subhrajit Sinha Roy

Team Members:

Name	Class Roll	University Roll
Dwaipayan Bhattacharjee	ECE2021/016	11700321071
Trinjan Dutta	ECE2021/033	11700321018
Rishav Pramanik	ECE2021/038	11700321051

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2. System Architecture

Block Diagram Overview

┌─────────────────┐    ┌─────────────────┐    ┌─────────────────┐
│   IR Sensors    │───▶│   Arduino UNO   │◄──▶│ Ultrasonic      │
│   (Left/Right)  │    │ (Microcontroller)│    │ Sensor          │
└─────────────────┘    └─────────────────┘    └─────────────────┘
                              │
                              ▼
                    ┌─────────────────┐
                    │ Motor Driver    │
                    │ (L298N)         │
                    └─────────────────┘
                              │
                              ▼
                    ┌─────────────────┐    ┌─────────────────┐
                    │ DC Motors       │───▶│ Wheels &        │
                    │ (300 RPM × 4)   │    │ Chassis         │
                    └─────────────────┘    └─────────────────┘
                              ▲
                              │
                    ┌─────────────────┐
                    │ 12V Battery     │
                    │ Power Supply     │
                    └─────────────────┘

Component Roles

• Arduino UNO: Central processing unit managing all system operations
• Motor Driver (L298N): Interface between Arduino and DC motors for speed/direction control
• DC Motors: Four 300 RPM Johnson motors providing movement capability
• Ultrasonic Sensor: Distance measurement for maintaining safe following distance
• IR Sensors: Human heat signature detection for target identification
• Power Supply: 12V rechargeable battery system for portable operation

Circuit Connections

Motor Driver L298N Connections:

L298N Pin	Arduino Pin	Function
ENA	Pin 9 (PWM)	Motor A Speed Control
IN1	Pin 2	Motor A Direction
IN2	Pin 3	Motor A Direction
IN3	Pin 4	Motor B Direction
IN4	Pin 5	Motor B Direction
ENB	Pin 10 (PWM)	Motor B Speed Control

Sensor Connections:

Sensor	Arduino Pin	Function
Ultrasonic Trig	Pin 7	Distance Trigger
Ultrasonic Echo	Pin 6	Distance Echo
Left IR	Pin 11	Left Side Detection
Right IR	Pin 12	Right Side Detection

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3. Hardware Components

Required Components List

Component	Quantity	Specifications	Purpose
Arduino UNO	1	ATmega328P, 16MHz	Main microcontroller
Motor Driver L298N	1	Dual H-Bridge, 2A	Motor control interface
Johnson DC Motors	4	300 RPM, 12V	Locomotion system
IR Sensors	2	Infrared proximity sensors	Human detection
Ultrasonic Sensor	1	HC-SR04, 2-400cm range	Distance measurement
Jumper Wires	20+	Male-to-male/female	Circuit connections
Robot Chassis	1	Aluminum/Acrylic frame	Structural support
Wheels	4	Rubber, compatible with motors	Ground contact
12V Battery Pack	1	Rechargeable Li-ion/NiMH	Power supply
Breadboard	1	Half-size recommended	Prototyping connections

Component Specifications

Arduino UNO

• Microcontroller: ATmega328P
• Operating Voltage: 5V
• Input Voltage: 7-12V (recommended)
• Digital I/O Pins: 14 (6 PWM outputs)
• Analog Input Pins: 6
• Flash Memory: 32KB

L298N Motor Driver

• Logic Voltage: 5V
• Motor Voltage: 5V-35V
• Logic Current: 0-36mA
• Motor Current: 2A (per channel)
• Max Power: 25W

Ultrasonic Sensor (HC-SR04)

• Operating Voltage: 5V DC
• Operating Current: 15mA
• Working Frequency: 40Hz
• Range: 2cm - 4m
• Accuracy: 3mm

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4. Algorithm and Implementation

System Initialization

1. Pin Configuration: Set up motor control pins as outputs and sensor pins as inputs
2. Serial Communication: Initialize debugging interface at 9600 baud rate
3. Motor Calibration: Ensure all motors are stopped initially
4. Sensor Validation: Verify all sensors are responding correctly
5. System Ready: 2-second stabilization delay before operation

Main Control Algorithm

START
│
├── READ SENSORS
│   ├── Ultrasonic Distance Measurement
│   └── IR Sensor Detection (Left/Right)
│
├── DECISION MAKING LOGIC
│   │
│   ├── IF Distance < MIN_DISTANCE (10cm)
│   │   └── EMERGENCY STOP → MOVE BACKWARD
│   │
│   ├── IF Right IR Detected AND Left IR Clear
│   │   └── TURN RIGHT
│   │
│   ├── IF Left IR Detected AND Right IR Clear
│   │   └── TURN LEFT
│   │
│   ├── IF Both IR Sensors Detect Human
│   │   ├── IF Distance in SAFE_RANGE (20-50cm)
│   │   │   └── MOVE FORWARD
│   │   ├── IF Distance > MAX_DISTANCE
│   │   │   └── MOVE FORWARD (APPROACH)
│   │   └── ELSE → MAINTAIN POSITION
│   │
│   └── IF No IR Detection
│       ├── IF Object in Ultrasonic Range
│       │   └── MOVE FORWARD SLOWLY
│       └── ELSE → STOP AND WAIT
│
├── MOTOR CONTROL EXECUTION
│   ├── Set Motor Directions
│   ├── Apply PWM Speed Control
│   └── Monitor Movement
│
└── LOOP BACK TO START

Movement Functions

Forward Movement

• Both motors rotate in forward direction
• Equal speed for straight line motion
• Speed adjustable based on distance

Turning Operations

• Turn Left: Reduce left motor speed, maintain right motor speed
• Turn Right: Reduce right motor speed, maintain left motor speed
• Sharp Turns: Reverse one motor while maintaining forward on other

Safety Features

• Collision Avoidance: Immediate stop when obstacle too close
• Speed Regulation: Variable speed based on target distance
• Emergency Backup: Reverse movement when critically close

Sensor Processing

Ultrasonic Distance Calculation

distance = (pulse_duration * 0.034) / 2;

• Pulse Duration: Time taken for sound wave to return
• Speed of Sound: 343 m/s (0.034 cm/µs)
• Distance Formula: (Time × Speed) ÷ 2 (round trip)

IR Sensor Logic

• HIGH Signal: Human heat signature detected
• LOW Signal: No detection or obstacle
• Dual Sensor: Determines direction of human movement

Code Structure

Key Constants

#define SAFE_DISTANCE 20    // Optimal following distance (cm)
#define MAX_DISTANCE 50     // Maximum detection range (cm)
#define MIN_DISTANCE 10     // Collision avoidance threshold (cm)
#define MOTOR_SPEED 150     // Base movement speed (0-255)
#define TURN_SPEED 100      // Turning operation speed

Main Functions

• readSensors(): Collect data from all sensors
• makeDecision(): Process sensor data and determine action
• moveForward(): Execute forward movement
• turnLeft()/turnRight(): Execute turning movements
• stopMotors(): Emergency stop function

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5. Results and Future Scope

Experimental Results

Testing Phases

1. Component Testing: Individual sensor and motor validation
2. Integration Testing: Combined system functionality verification
3. Distance Calibration: Optimal following distance determination
4. Movement Testing: Navigation accuracy and responsiveness evaluation
5. Real-world Testing: Human following performance in various environments

Performance Metrics

• Detection Range: 2-50 cm effective range
• Following Accuracy: ±5 cm distance maintenance
• Response Time: <200ms for direction changes
• Battery Life: 2-3 hours continuous operation
• Success Rate: 95% human tracking accuracy in a controlled environment

Test Results Summary

Test Parameter	Result	Status
Distance Maintenance	20±3 cm	✅ Excellent
Direction Tracking	95% accuracy	✅ Excellent
Obstacle Avoidance	100% collision-free	✅ Perfect
Battery Performance	2.5 hours average	✅ Good
Response Time	150ms average	✅ Excellent

Future Enhancements

Short-term Improvements (1-3 months)

1. Enhanced Sensor Array

   • Add additional IR sensors for 360° detection
   • Implement camera module for visual tracking
   • Include a gyroscope for better orientation control

2. Algorithm Optimization

   • Implement PID control for smoother movement
   • Add predictive tracking for faster humans
   • Develop machine learning for behavior adaptation

Medium-term Developments (3-6 months)

1. Wireless Communication

   • Bluetooth Integration: Remote monitoring and control
   • Wi-Fi Connectivity: Internet-based operation and data logging
   • Mobile App: Real-time status and control interface

2. Advanced Navigation

   • SLAM Implementation: Simultaneous Localization and Mapping
   • Path Planning: Optimized route calculation
   • Multi-target Tracking: Follow multiple humans simultaneously

Long-term Vision (6-12 months)

1. Military and Security Applications

   • Surveillance Capabilities: Real-time video recording and transmission
   • Perimeter Monitoring: Autonomous patrol functionality
   • Threat Detection: Integration with security systems

2. Disaster Management

   • Search and Rescue: Human detection in disaster scenarios
   • Medical Emergency: First aid supply delivery
   • Environmental Monitoring: Data collection in hazardous areas

3. Multi-Robot Coordination

   • Swarm Intelligence: Coordinated multi-robot operations
   • Task Distribution: Collaborative problem-solving
   • Communication Network: Inter-robot data sharing

Practical Applications

Healthcare and Assistance

• Elderly Care: Personal assistance and mobility support
• Hospital Navigation: Guide patients and visitors
• Rehabilitation: Physical therapy assistance

Commercial and Industrial

• Warehouse Operations: Inventory tracking and management
• Manufacturing: Worker safety and assistance
• Retail: Customer service and navigation

Educational and Research

• STEM Education: Robotics learning platform
• Research Tool: Human-robot interaction studies
• Competition Platform: Robotics contests and demonstrations

Technical Challenges and Solutions

Current Limitations

1. Environmental Sensitivity: IR sensors affected by ambient light
2. Battery Life: Limited operational duration
3. Terrain Limitations: Smooth surface requirement
4. Single Target: Can only follow one person at a time

Proposed Solutions

1. Sensor Fusion: Combine multiple sensor types for reliability
2. Power Management: Implement sleep modes and energy optimization
3. Adaptive Control: Terrain-specific movement algorithms
4. Computer Vision: Camera-based multi-target tracking

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🚀 Getting Started

Prerequisites

• Arduino IDE (version 1.8.0 or higher)
• Basic understanding of electronics and programming
• Soldering equipment (for permanent connections)
• Multimeter for troubleshooting

Installation Steps

1. Hardware Assembly

   1. Mount motors on chassis
   2. Install wheels on motors
   3. Connect the motor driver to Arduino
   4. Mount sensors on the front of the chassis
   5. Connect power supply
   6. Secure all connections
   

2. Software Setup

   1. Download Arduino IDE
   2. Connect Arduino UNO via USB
   3. Select the correct board and port
   4. Upload the provided code
   5. Open Serial Monitor for debugging
   

3. Calibration Process

   1. Test individual motor movements
   2. Calibrate sensor readings
   3. Adjust distance thresholds
   4. Fine-tune movement speeds
   5. Validate complete system operation
   

Usage Instructions

1. Power On: Connect 12V battery and Arduino power
2. Initialization: Wait for system startup (2 seconds)
3. Positioning: Place robot behind target human
4. Operation: The Robot will automatically detect and follow
5. Monitoring: Use Serial Monitor for real-time status

Troubleshooting Guide

Issue	Possible Cause	Solution
Robot doesn't move	Power/connection issue	Check battery and motor connections
Erratic movement	Sensor interference	Recalibrate sensors, check wiring
Poor following	Distance threshold	Adjust SAFE_DISTANCE constant
No detection	IR sensor failure	Test sensors individually
Continuous rotation	Wiring error	Verify motor driver connections

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📊 Technical Specifications

Performance Parameters

• Maximum Speed: 1.2 m/s
• Turning Radius: 30 cm minimum
• Detection Range: 2-50 cm
• Operating Voltage: 12V DC
• Current Consumption: 2-3A (motors active)
• Weight: 2.5 kg approximately
• Dimensions: 25cm × 20cm × 15cm

Environmental Conditions

• Operating Temperature: 0°C to 50°C
• Humidity: 20% to 80% (non-condensing)
• Surface: Flat to moderate inclines (up to 15°)
• Lighting: Indoor/outdoor (IR sensors may vary)

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🤝 Contributing

We welcome contributions to improve this project! Areas for development:

• Enhanced algorithms for better tracking
• Additional sensor integration
• Power optimization techniques
• User interface improvements
• Documentation enhancements

How to Contribute

1. Fork the repository
2. Create a feature branch
3. Make your improvements
4. Test thoroughly
5. Submit a pull request with a detailed description

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📝 License

This project is developed for educational purposes at RCC Institute of Information Technology. Feel free to use and modify for academic and research purposes.

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👥 Authors and Acknowledgments

Development Team:

• Dwaipayan Bhattacharjee - Hardware Integration and Testing
• Trinjan Dutta - Software Development and Algorithm Design
• Rishav Pramanik - Circuit Design and Documentation

Special Thanks:

• Dr. Subhrajit Sinha Roy - Project Supervision and Guidance
• RCC Institute of Information Technology - Laboratory and Resources
• Department of ECE - Technical Support and Facilities

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This project demonstrates the practical application of embedded systems, sensor technology, and robotics in creating intelligent autonomous systems for human-robot interaction.