Course teached as: B024409 - INGEGNERIA INVERSA E PRODUZIONE ADDITIVA Second Cycle Degree in MECHANICAL ENGINEERING Curriculum PROGETTAZIONE
Teaching Language
italian
Course Content
-R.E. motivations, processes and technologies
-Processing of scanned data
-Geometry reconstruction from scanned data
-Practical demonstration of 3D scanners
-Practical demonstration of geometry reconstructions from 3D scanned data
-Practical examples and applications of R.E. techniques
-R.P. motivations and technologies
-The STL file format
-Polymeric materials
-R.P. Techniques
-Rapid Tooling
-Rapid Manufacturing
No reference books are available for the subjects of the course.
Support material consists of a set of slides used by the teacher during the lessons. Students will be provided with such material.
Learning Objectives
AQUIRED SKILLS
Part A: Reverse Engineering
Ability to cope with the issue of 3D model reconstruction of a real object by means of:
-choice of the most suitable 3D scanning device;
-definition of the necessary procedures for simplify/process the scanned data
-definition of the characteristics of the 3D model to be reconstructed and choice of the most suitable reconstruction technique.
Part B: Rapid Prototyping
Ability of pre-processing the CAD model of the starting object, in order to make it “usable” by the prototyping system.
Knowledge of the R.P. machines, techniques and of the respective usable materials.
Ability to define, for a given object to be built, the optimal R.P., rapid tooling and/or rapid manufacturing process.
Prerequisites
Base knowledge of Computer Aided Design and manufacturing technologies
Teaching Methods
Part A: Reverse Engineering
The first part of the program is dedicated to theory and practice of devices and techniques for R.E.; the second deals with practical demonstrations of 3D scanning machines and real case studies.
Part B: Rapid Prototyping
Most of the lessons are dedicated to the presentation of R.P. technologies (machines and processes); afterwards some practical demonstrations, about the CAD model processing and the definition of process parameters, will be provided.
Further information
In order to take the exam, please register to:
http://sol.unifi.it/prenot/prenot
Type of Assessment
The exam test consists of a series of open questions, to be answered mostly in a colloquial form.
Course program
Part A: Reverse Engineering
1. R.E. motivations and application fields
2. R.E. process definition
3. Introduction to R.E. technologies
4. Classification of 3D scanning methodologies
5. Contact systems
a. general characteristics
b. active systems
c. passive systems
d. point mode and scanning mode acquisition
e. scanning strategies and possible error sources
6. No contact systems
a. general characteristics
b. optical systems
i. introduction to cameras and epipolar geometry
ii. calibration of a set of cameras
iii. passive optical systems
1. passive stereo-vision
2. shape from shading
3. shape from texture
4. shape from focus-defocus
5. shape from silhouette
iv. active optical systems
1. laser-camera triangulation
2. active stereo-vision (laser and structured light)
3. time of flight scanning
7. Pre processing of scanned data
a. overlapping and oversampling
b. simplification and registration of point clouds
i. techniques for scan lines
ii. techniques for 2.5 D point clouds
iii. techniques for 3D point clouds
c. error sources and dimensional assessment
8. 3D modeling: geometry reconstruction starting from scanned data
a. tessellation and triangulation
b. reconstruction by means of primitives and features
c. reconstruction by means of sections
d. reconstruction by means of surface patches
9. Practical demonstrations of a series of 3D scanners
10. Practical demonstrations of geometry reconstructions of objects starting from scanned data
11. Case studies
Part B: Rapid Prototyping
1. R.P. Motivations and application fields
2. Introduction to R.P. technologies
3. R.P. techniques classification
4. The STereoLithography Interface Format (STL)
a. file content description
b. geometry errors management and dedicated software packages
5. Polymeric materials
6. R.P. Techniques; processes, machines, materials
a. Stereolithography (SLA)
b. Solid Ground curing (SGC)
c. Fused Deposition Modelling (FDM)
d. Laminated Object Manufacturing (LOM)
e. Selective Laser Sintering (SLS)
f. Polyjet method
g. Three Dimensional Printing (3DP)
h. Multi Jet Modelling (MJM)
i. Ballistic Particle Manufacturing (BPM)
l. Drop On Demand (DOP)
h. R.P. with metal material
i. Selective Laser Melting (SLM)
ii. Electron Beam Melting (EBM)
iii. Laser Engineered Net Shaping (LENS)
7. Rapid Tooling