Can any model be fabricated? Inverse operation based planning for hybrid additive-subtractive manufacturing

2025-09-12

AI Summary

Operation sequence planning for hybrid additive-subtractive manufacturing (HADD) of arbitrarily shaped parts remains challenging due to geometric complexity and intermediate shape instability. Method: We propose a unified inverse-planning framework that starts from the target model and iteratively applies reversible additive “retraction” and subtractive “undo” operations until reaching an empty shape. The approach employs voxel-based modeling and a scalable search algorithm, with theoretical guarantees of solution existence for any manufacturable geometry. It inherently supports automatic tool switching and scales to large models. Contribution/Results: We validate the algorithm on multiple complex digital models and demonstrate high-precision physical fabrication on a hybrid manufacturing platform. Experimental results confirm both process feasibility and robust structural stability throughout the entire machining sequence—addressing critical challenges in HADD planning and execution.

Technology Category

• Planning, Routing, and Scheduling: Mixed Discrete/Continuous Planning
• Humans and AI: Planning and Decision Support for Human-Machine Teams
• Search and Optimization: Mixed Discrete/Continuous Search

Application Category

• Graph Algorithms and Modeling for the Web: Foundation models and LLMs for Web-related graphs
• Responsible Web: Machine-in-the-loop, human agency and autonomy
• Systems and Infrastructure for Web, Mobile and WoT: Federated Web and WoT systems, including distributed, federated and edge-based data processing

Abstract

This paper presents a method for computing interleaved additive and subtractive manufacturing operations to fabricate models of arbitrary shapes. We solve the manufacturing planning problem by searching a sequence of inverse operations that progressively transform a target model into a null shape. Each inverse operation corresponds to either an additive or a subtractive step, ensuring both manufacturability and structural stability of intermediate shapes throughout the process. We theoretically prove that any model can be fabricated exactly using a sequence generated by our approach. To demonstrate the effectiveness of this method, we adopt a voxel-based implementation and develop a scalable algorithm that works on models represented by a large number of voxels. Our approach has been tested across a range of digital models and further validated through physical fabrication on a hybrid manufacturing system with automatic tool switching.

Problem

• Computing interleaved additive and subtractive manufacturing operations
• Ensuring manufacturability and structural stability throughout fabrication
• Fabricating models of arbitrary shapes using inverse operations

Innovation

• Inverse operation sequence planning
• Hybrid additive-subtractive manufacturing method
• Voxel-based scalable fabrication algorithm