Methodological contribution to generic trajectory generation for additive manufacturing with a robotic manipulator

• Autor(a) principal: Gil, António Pedro Ascenso
• Data de Publicação: 2020
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10362/114032
• topic: Additive Manufacturing; FFF; Trajectory Generation; Robotic Manipulator; Fifth Order Polynomials; Optimization; Domínio/Área Científica::Engenharia e Tecnologia::Engenharia Mecânica

Additive manufacturing as shown substantial improvements on the last decade, however the principles of FFF (Fused Filament Fabrication) technology are essentially unchanged. With the attachment of a material extruding unit to a robotic manipulator, boundaries once set as planar slicing are no longer imposed. A solution for this matter is one of the main focuses of the “Optimal Non Planar Trajectory Generation for Additive Manufacturing” ongoing investigation. This investigation aims to develop 3D object processor (also known as a slicer) coupled with a robotic manipulator. The new slicing program will perform slicing in 3D surfaces, reducing the need for support structures and allowing a 3D surface deposition that best fits mechanical properties of specific materials, increasing structural reliability of the parts. As a part of development to the project, a study is here carried out where, when using a conventional planar slicer, geometries are stripped down to the cloud of points given by G-Code commands, and trajectories are processed to simulate the real movement of the FFF device, using parameterized 5th degree polynomial equations working within a 2D environment. Scenarios demanding closer attention and later described as “sharp edges” (where the FFF process would cause complications) are introduced and a method is proposed on how to perform the polynomial interpolation on these cases. Time instants are normalized, velocities are described and compared with extrusion speeds. Limits for these are calculated. Two case studies are introduced and studied basing on two distinct geometries: a cylinder and a cube. The objectives undertaken that lead to the creation of the present dissertation were overall successfully achieved with the proposed methodology. The applicability of the method has shown to be successful on the cases where there is continuous extrusion that is uninterrupted by G0 commands withing the original G-Code files.