PCB Detection

A hybrid active-learning based defect detection pipeline for industrial PCB AOI systems.
🥇 Winner of the Shokz Global Excellence and Innovative Talent Summer School 2025 Gold Award.

📽️ Demo Video (MP4)

🧩 Introduction

This project addresses the high false-alarm rate in traditional AOI (Automatic Optical Inspection) systems used in PCB manufacturing.
The proposed AI-powered re-inspection system integrates active learning and improved YOLOv11 algorithms to intelligently verify suspected defects detected by AOI, significantly reducing manual workload and false alarms.

Key goals:

• Reduce AOI false alarm rate from ~28%, achieving a miss rate below 0.07% based on real PCB defect data from Huizhou Gaoshengda Technology Co., Ltd.
• Maintain real-time inspection speed of 666 FPS
• Support distributed inference + centralized training
• Enable continuous self-improvement through human-in-the-loop feedback

⚙️ System Architecture

The system follows a “Detection–Training–Annotation” closed-loop design:

1. Detection Frontend – Receives AOI-captured images and performs real-time inference using a lightweight YOLOv11-based model.
2. Training Backend – Performs model retraining using uncertain or misclassified samples, employing the RAC2F feature-fusion module for improved micro-defect detection.
3. Annotation Interface – Provides a user-friendly web interface for rapid human verification and feedback. Corrections are fed back for continuous model improvement.

🏭 Industrial Applications

• Mass Production QA – Real-time, 24/7 defect detection matching SMT production speed.
• Adaptive Model Updating – Self-adjusts for multi-batch production without manual reconfiguration.
• Low-Cost Deployment – Runs on standard GPUs (RTX 3070Ti / 2080Ti), no hardware replacement required.
• Educational Value – Enables teaching and research in AI + Industrial Inspection.

Figure: System deployment architecture of the distributed AI inspection solution. Multiple AOI machines connect to edge inference nodes powered by RTX 3070Ti GPUs, while a central server equipped with an RTX 2080Ti handles model training and data synchronization, forming a "distributed inference + centralized training" closed-loop system.

🧰 Tech Stack

• Backend: Python, PyTorch, YOLOv11, FastAPI
• Frontend: Vue 3 + Vite + TypeScript
• Training: Active Learning, RAC2F Feature Fusion, Distributed Training
• Hardware: RTX 3070Ti (Edge Inference), RTX 2080Ti (Central Training)

Environment Setup

This project is developed with Python 3.10. It is recommended to use Conda to create an isolated virtual environment.

1️⃣ Create and Activate a Conda Environment

conda create -n yolov11 python=3.10
conda activate yolov11

2️⃣ Install JupyterLab (Optional, for Interactive Development)

conda install jupyterlab

3️⃣ Install PyTorch + CUDA 11.8

Please choose the appropriate CUDA version according to your GPU driver. Example for CUDA 11.8:

pip install torch==2.0.0+cu118 torchvision==0.15.1+cu118 --extra-index-url https://download.pytorch.org/whl/cu118

4️⃣ Install Project Dependencies

pip install requirements.txt

If any packages are missing, install them manually according to the error message: pip install <package_name>

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Dataset Directory Structure

The dataset is organized as follows, tailored for the PCB defect detection task:

./
├── backend_detect/                    # Backend: Detection service module (e.g., active learning, inference service)
│   ├── active_learning/               # Core logic for active learning
│   ├── datasets/simulate_ready_push/  # Directory for simulated datasets
│   ├── runs/active_learning/          # Logs and model checkpoints during active learning
│   ├── server.py                      # Entry point for detection service
│   └── pre.py                         # Data preprocessing script

├── backend_model/                     # Backend: Model training module (based on YOLO/Ultralytics)
│   ├── active_learning/               # Shared active learning module with backend_detect
│   ├── docker/                        # Docker deployment configurations
│   ├── docs/                          # Project documentation directory
│   ├── examples/                      # Example scripts and configuration files
│   ├── runs/active_learning/          # Training and inference output results
│   ├── tests/                         # Unit testing module
│   ├── ultralytics/                   # YOLO source code and customized components
│   ├── *.yaml                         # Dataset configuration files (e.g., BJ-PCB, GSD-PCB)
│   ├── detect.py                      # Inference script
│   ├── train.py / val.py / test.py    # Training, validation, and testing scripts
│   ├── server.py                      # Entry point for training service
│   └── image_labeler.py               # Image labeling logic (for interactive annotation)

├── frontend/                          # Frontend: Visualization interface built with Vue + TypeScript
│   ├── public/                        # Static assets directory
│   ├── src/                           # Frontend source code
│   │   ├── assets/                    # Image and media resources
│   │   ├── components/                # Core UI components (e.g., annotation area, results table)
│   │   │   ├── ControlPanel.vue
│   │   │   ├── DetectionArea.vue
│   │   │   ├── LabelArea.vue
│   │   │   ├── ResultTable.vue
│   │   │   └── TransfImg.vue
│   │   ├── stores/                    # State management modules (Pinia)
│   │   │   ├── manageImg.ts
│   │   │   └── manageModel.ts
│   │   └── main.ts / App.vue          # Project entry point
│   ├── package.json                   # Frontend dependency management
│   └── vite.config.ts                 # Build configuration (Vite)

├── requirements.txt                   # Python dependency list (backend environment)
├── README.md                          # Project documentation

Notes

• Dataset_Name/images/ and Dataset_Name/labels/ are used for training, validation, and testing.
• raw/Dataset_Name/Annotations/ contains the original annotation files (e.g., XML) for each defect category.
• raw/Dataset_Name/labels/ stores the converted YOLO-format labels used for training.
• It is recommended to organize the raw data into the YOLO-required structure images/ and labels/ during the preprocessing stage.

Example Annotation File

YOLO-format label file（.txt）：

<class_id> <x_center> <y_center> <width> <height>

All values are normalized to the range [0, 1].

For dataset splitting and format conversion, you may refer to the provided pre.py script or write your own batch processing tool.

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🧭 Usage Instructions

This project consists of two backend modules and one frontend visualization interface. Follow the steps below to set up and run the system:

✅ Install Dependencies

# Install backend dependencies
pip install -r requirements.txt

# Install frontend dependencies
cd frontend
npm install

🚀 Launch Services

# Start Backend Service 1: Detection Service
cd backend_detect
python server.py

# Start Backend Service 2: Model Service
cd backend_model
python server.py

# Start Frontend Service (Vue + Vite)
cd frontend
npm run dev

Figure: Frontend interface of the PCB defect detection system based on YOLOv11. The left panel allows model selection and confidence threshold adjustment; the middle panel visualizes real-time detection results; the right panel supports manual annotation and feedback for active learning.

⚙️ Configure Service Endpoints (Optional)

The communication addresses among different modules are configured through .env files:

路径	功能说明
backend_detect/.env	Defines the IP and port for frontend access to backend\_detect
backend_model/.env	Defines the address for backend\_model to access backend\_detect
frontend/.env	Defines the addresses for the frontend to access both backends

Example configuration for frontend/.env：

VITE_DETECT_API_URL=http://localhost:8000
VITE_MODEL_API_URL=http://localhost:8001

Adjust the IP and port numbers according to your actual runtime environment to ensure smooth communication among services.

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⚠️ Notes

• If your GPU driver does not support CUDA 11.8, please visit the official PyTorch website to select a compatible version.
• The project supports Windows and Linux systems; Conda is recommended for Python environment management.
• If dependency conflicts or installation errors occur, try updating Conda first:

conda update -n base -c defaults conda