A practical guide to intelligent recognition and integration of CAD drawings enabled by large models

1. CAD drawing intelligent recognition technology architecture

1. Multimodal data preprocessing (core step)

•  The vector graphics structured analysis uses the frame recognition technology of the Wanyi drawing large model to automatically cut the sub-graph modules such as the plan, elevation, and node details in the drawing to establish the spatial topological relationship between the drawings. Through the object detection capability of the DeepSeek Janus-Pro model, the outlines of building components such as doors, windows, and pipelines can be accurately identified, with a positioning accuracy of ±0.5mm.

•  Semantic annotation enhancement Combined with the text understanding ability of the "XiTu" large model of the Fourth Construction Group, semantic analysis of design instructions and annotation symbols in CAD drawings is performed. For example, the "GL1" annotation is automatically associated with the corresponding I-beam attribute parameters to achieve triangular mapping of component ID-attribute-position.

2. Large model selection strategy

2. The whole process of intelligent processing of CAD drawings

1. Drawing parsing and knowledge extraction

•  Intelligent component identification uses a multi-model collaborative mechanism. DeepSeek first detects the contours of equipment such as compressors and condensers, and then the "Xitu" model parses attribute fields such as power parameters and connection relationships, and finally generates a BOM list with three-dimensional coordinates.

•  Design specification verification integrates the intelligent drawing review function of the Wanyi large model to automatically detect whether the pipeline spacing meets the requirements of GB50755 specifications, and the error positioning accuracy reaches pixel level.

2. Knowledge Graph Construction

3. Intelligent integration solution for drawings

1. Dynamic tile generation technology

•  Parametric block creation is based on the block storage process recommended by the Tencent Cloud Developer Community. Standard components recognized by large models (such as air-conditioning fan coils) are automatically encapsulated into smart blocks with attribute labels, supporting dynamic adjustment of size parameters.

•  Intelligent matching recommendation When the designer draws the air conditioning system diagram, the system automatically recommends the fan model that meets the GB/T19232 standard and associates the three-dimensional information such as installation spacing and pipe connection direction.

2. Multi-system collaborative interface

•  The BIM platform docking calls the ezdxf library through Python, automatically writes the identified device coordinates and attribute parameters into the Revit family library, and realizes the conversion of two-dimensional drawings to three-dimensional models in seconds.

•  The ERP system integration utilizes the RAG technology of the Wanyi large model to intelligently match the equipment list in the drawing with the material coding of the procurement system, increasing the efficiency of procurement list generation by 5 times.

4. Industry Implementation Cases

Implementation effect of a central air conditioning manufacturer :

1. Drawing analysis: complete annotation of more than 100,000 equipment components within 2 hours (traditionally it takes 2 weeks)
2. Error detection: Automatically found 137 design defects such as insufficient slope of condensate pipes
3. Drawing efficiency: Standard module drawing time is shortened from 6 hours to 15 minutes
4. Cost control: Reduce material waste by 5% through intelligent calculation

V. Implementation Path Suggestions

1. Initial preparation (1-2 weeks) • Build a GPU cluster (NVIDIA A100*8 is recommended) • Clean historical drawing data (focus on processing versions below DWG2007)

2. Model deployment (3-4 weeks) • Select hybrid architecture: Wanyi Model (design management) + DeepSeek (manufacturing analysis) • Develop data middleware: support AutoCAD2025 and ZWCAD2024 dual platforms

3. System Integration (2-3 weeks) • Connect with PLM system: develop drawing version comparison API • Build smart library: store 50,000+ standard parts by GB/T classification