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Face Tracking Robot

3-Wheeled Robot with Pan-Tilt Mechanism and Vision-Based Tracking

Face Tracking Robot

📋 Project Overview

The Face Tracking Robot is an autonomous robotic system that uses computer vision to detect and track human faces in real-time. The robot features a 3-wheeled omnidirectional base for smooth movement and a pan-tilt camera mechanism for precise face tracking. Built using ROS2, the system demonstrates integration of perception, control, and actuation in a complete robotic application.

This project showcases practical robotics skills including sensor integration, control systems, path planning, and real-time computer vision processing, making it an excellent example of end-to-end robotic system development.

💡 Problem Statement

Building an autonomous face tracking system involves several challenges:

  • Real-time Processing: Face detection and tracking must operate at video frame rates
  • Robust Detection: Handling varying lighting conditions, angles, and occlusions
  • Precise Control: Smooth and accurate pan-tilt movements to keep face centered
  • Robot Navigation: Coordinating base movement with camera orientation
  • System Integration: Seamless communication between vision, control, and actuation modules
  • Latency Management: Minimizing delay between detection and robot response

⚡ Solution Approach

The system integrates multiple components:

  • Face Detection: Haar cascades or deep learning-based face detection (MTCNN/YOLO)
  • Face Tracking: Kalman filter for predictive tracking and smooth following
  • Pan-Tilt Control: PID controllers for precise camera positioning
  • Robot Base Control: Differential drive or omnidirectional control for base movement
  • ROS2 Architecture: Modular nodes for vision, control, and actuation
  • Coordinate Transformation: Converting image coordinates to robot frame

🛠️ Technical Implementation

Hardware Components

  • Robot Base: 3-wheeled omnidirectional platform with encoders
  • Camera System: USB camera or Raspberry Pi camera module
  • Pan-Tilt Mechanism: Two servo motors for camera orientation
  • Computing Unit: Raspberry Pi or onboard computer for processing
  • Motor Controllers: PWM-based control for smooth movement

Software Architecture

  • ROS2 Nodes: Modular architecture with separate nodes for each component
  • Vision Node: OpenCV-based face detection and tracking
  • Control Node: PID controllers for pan-tilt and base movement
  • Actuation Node: Motor control and servo positioning
  • Topic Communication: Camera images, face coordinates, and control commands
  • TF2: Coordinate frame transformations between camera and robot base

Control Algorithms

  • Face Detection: Haar cascades or deep learning models for robust detection
  • Kalman Filtering: Predictive tracking to handle temporary occlusions
  • PID Control: Proportional-Integral-Derivative controllers for smooth tracking
  • Coordinate Mapping: Image pixel coordinates to pan-tilt angles
  • Velocity Control: Smooth velocity commands for base movement

🏆 Key Achievements

  • Real-time face tracking at 30 FPS
  • Smooth and responsive pan-tilt movements
  • Robust tracking under varying lighting conditions
  • Successful integration of vision, control, and actuation
  • Modular ROS2 architecture for easy extension

💡 Challenges Overcome

  • Synchronizing multiple control loops (pan, tilt, base)
  • Handling face detection failures and occlusions
  • Calibrating camera-to-robot coordinate transformations
  • Optimizing PID parameters for smooth tracking
  • Managing computational resources for real-time processing

📚 Key Learnings

  • ROS2 Development: Building modular robotic systems with ROS2
  • Computer Vision: Real-time face detection and tracking techniques
  • Control Systems: PID control implementation for robotic applications
  • Robotic Integration: Combining perception, planning, and actuation
  • Coordinate Systems: Understanding and managing multiple reference frames
  • Real-time Systems: Optimizing for low-latency performance

🚀 Future Enhancements

  • Multi-face tracking and person re-identification
  • Deep learning-based face recognition for personalized interaction
  • Autonomous navigation to follow a person
  • Gesture recognition for human-robot interaction
  • Integration with SLAM for mapping and navigation
  • Voice commands for hands-free control
  • Mobile app for remote monitoring and control

Skills Demonstrated

Robotics ROS2 OpenCV Computer Vision Control Systems PID Control Face Detection Kalman Filter Python C++ Embedded Systems Sensor Integration Real-time Systems Motor Control