Interface-Based Search and Automatic Reassembly of CAD Models for Database Expansion and Model Reuse

Abstract

This paper introduces a new framework for reassembling CAD models of mechanical parts. The generated CAD assemblies are well-constrained, with collision-free parts, and they are ready-to-use for downstream applications. First, input dead CAD models candidate for the reassembly are sorted following a part-by-part interface-based identification algorithm that is capable of characterizing each part according to the assembly slots and interfaces it offers. The slots are then hashed, and the resulting keys are used for fast search of parts in the database. Thus, the parts that can be assembled are quickly identified, and their assembly can be considered according to various scenarios. To support the reassembly steps and satisfy the constraints associated with the specified interfaces, a collision-free kinematic constraint solver is also proposed. During the reassembly steps, the geometry of the slots can also be automatically modified to adjust their dimensions, in order to ensure a perfect fit and to avoid interference at the level of the interfaces. The resulting database can also be further expanded while modifying the relative positions/orientations of the assembled parts. The approach is illustrated on several test cases covering different exploitation scenarios, ranging from simple model reuse to database expansion for machine learning-based applications. Such an automatic reassembly process is particularly innovative, and it clearly paves the way for smart assembly procedures.