reverse engineering – recent advances and applications - OpenLibra

XII Preface
the geometry and topology of complex shapes from low-level unorganized 3D
scanning data, such as point clouds, are presented. The focus here is on robust
extraction of shape information with guaranteed quality properties from such 3D
scans, and also on the efficient computation of such shapes from raw scans involving
millions of sample points. Secondly, methods and techniques are presented which
help the process of manufacturing 3D shapes from information which is reverse
engineered from previously manufactured shapes. Here, the focus is on guaranteeing
required quality and cost related metrics throughout the entire mechanical
manufacturing process.
In Chapter 6, Keller et al. present a multiresolution method for the extraction of
accurate 3D surfaces from unorganized point clouds. Attractive aspects of the method
are its simplicity of implementation, ability to capture the shape of complex surface
structures with guaranteed connectivity properties, and scalability to real-world point
clouds of millions of samples. The method is demonstrated for surface reconstruction
of detail object scans as well as for spatially large point clouds obtained from
environmental LiDaR scans.
In Chapter 7, Kaisarlis presents a systematic approach for geometric and dimensional
tolerancing in reverse engineering mechanical parts. Tolerancing is a vital component
of the accurate manufacturing process of such parts, both in terms of capturing such
variability in a physical model and in terms of extracting tolerancing-related
information from existing models and design artifacts using reverse engineering. A
methodology is presented where tolerancing is explicitly modeled by means of a
family of parameterizable tolerancing elements which can be assembled in tolerance
chains. Applications are presented by means of three case studies related to the
manufacturing of complex mechanical assemblies for optical sensor devices.
In Chapter 8, Chang presents a review of shape design and parameterization in the
context of shape reverse engineering. Extracting 3D parameterizable NURBS surfaces
from low-level scanned information, also called auto-surfacing, is an important
modeling tool, as it allows designers to further modify the extracted surfaces on a high
level. Although several auto-surfacing tools and techniques exist, not all satisfy the
same requirements and up to the same level. The review discusses nine auto-surfacing
tools from the viewpoint of 22 functional and non-functional requirements, and
presents detailed evaluations of four such tools in real-world case studies involving
auto-surfacing.
In Chapter 9, Mello et al. present a model for integration of mechanical reverse
engineering (RE) with design for manufacturing and assembly (DFMA). Their work is
motivated by the perceived added value in terms of lean development and
manufacturing for organizations that succeed in combining the two types of activities.
Using action research, they investigate the use of integrated RE and DFMA in two
companies involved in manufacturing home fixture assemblies and machine
measuring instruments respectively. Their detailed studies show concrete examples of