- The paper proposes a novel Fusion 360 plugin that automates CAD assembly synthesis using a three-tier subtyping system.
- It leverages knowledge-based engineering to annotate parts and generate functional assemblies, enabling faster and reusable designs.
- The approach improves design exploration efficiency while highlighting challenges in detailed performance specification.
Overview
Computer-aided design (CAD) is an essential tool in product development that aids in visualizing and creating detailed models for various parts and assemblies. However, the design of assemblies can often involve repetitive steps, which can be time-consuming and costly. To tackle this issue, a plugin for the CAD software package "Fusion 360" has been developed. This plugin aims to enhance the software with capabilities from knowledge-based engineering to automate the creation of assemblies, potentially lowering costs and development times.
Subtyping
The plugin introduces a subtyping system, which is key to managing how parts are characterized in the design process. The system is divided into three hierarchies: formats, parts, and attributes. In the formats hierarchy, types are associated with the physical geometry of connections, ensuring compatibility between mating parts. The parts hierarchy categorizes the intent of a part so that only sensible connections are considered in an assembly. Lastly, the attributes hierarchy captures any additional significant characteristics. By managing these hierarchies, the plugin can impact the synthesis of results, enhancing the design process's efficiency.
Annotating and Requesting
For the CAD parts to be prepared for automation, they must be annotated with types using the plugin's graphical user interfaces which are integrated into Fusion 360. This includes assigning unique identifiers to the parts and defining how they can be used in different configurations. To generate assemblies, users can request a set of assemblies by selecting a combination of types and specify propagated types, which represent the characteristics of the parts not directly annotated but can be deduced from elsewhere in the assembly.
Assembling
Once the parts are annotated and the types are requested, the plugin can automatically create synthesized assemblies. Using the information stored in JSON files, the plugin follows a set of instructions that depict the order in which parts should be inserted and how they should be structured to form the final CAD model. This method ensures that well-formed and functional assemblies are generated, such as robotic arms with varying degrees of freedom.
Accomplishments and Limitations
This new approach implemented via CLS-CAD showcases an important development in utilizing knowledge-based engineering within the CAD design stage. One notable accomplishment is that the plugin allows for parts to be reused across different product lines, aiding in exploring a wider design space without manual labor. However, there are limitations to the system's specification capabilities. Obtaining sufficient levels of detail in functionality and performance remains challenging, and there is currently a lack of mechanisms for filtering results based on specific numeric performance criteria.
Conclusion
The plugin represents an innovative solution for enhancing the reusability and automation of parts in the CAD design process. By synthesizing assemblies with a guarantee of correctness, the plugin saves designers time, allows for better exploration of design alternatives, and increases the reliability of the design process. Future work aims to address the current specification limitations and further integrate and optimize the plugin’s capabilities.