Yann Quinsat

Characterization of 3D surface topography in 5-axis milling

Within the context of 5-axis free-form machining, CAM software offers various modes of tool-path generation, depending on the geometry of the surface to be machined. Therefore, as the manufactured surface quality results from the choice of the machining strategy and machining parameters, the prediction of surface roughness in function of the machining conditions is an important issue in 5-axis machining. The objective of this paper is to propose a simulation model of material removal in 5- axis based on the N-buffer method and integrating the Inverse Kinematics Transformation. The tooth track is linked to the velocity giving the surface topography resulting from actual machining conditions. The model is assessed thanks to a series of sweeping over planes according to various tool axis orientations and cutting conditions. 3D surface topography analyses are performed through the new 3D roughness parameters proposed by recent standards.

Voxel-based Path Planning for 3D Scanning of Mechanical Parts

The paper deals with an original approach to scan path planning that applies for any type of sensors. The approach relies on the representation of the part surface as a voxel map. The size of each voxel is defined according to the sensor FOV. To each voxel, a unique point of view is associated in function of visibility and quality criteria. Whatever the sensor, the method provides a set of admissible points of view to ensure the surface digitizing with a given quality.

Towards a New Concept of In-Line Crankshaft Balancing by Contact Less Measurement: Process for Selecting the Best Digitizing System

Controlling the part’s balance of crankshafts are important issues for automotive manufacturers. Unbalance measurement is usually carried out using high-precision mechanical machines. The main objective of the present work is to replace mechanical measuring systems by a non-contact digitizing system, which permits the acquisition of the crankshaft surface. As the geometry to be measured presents a large variety of shapes and textures with accessibility issues, the definition of the best-suited scanning system related to geometrical and industrial constraints is a major issue.In this direction, the paper deals with the definition of a protocol based on quality indicators associated to the collected data to compare various digitizing systems. Those quality indicators are assessed thanks to simple artifacts measurement according to a specific procedure. The comparison protocol is applied to evaluate three triangulation based digitizing systems: Results allow us to identify well-adapted digitizing systems in relation to crankshaft balancing requirements.© 2012 ASME

Multi-scale surface characterization in additive manufacturing using CT

In additive manufacturing, the part geometry, including its internal structure, can be optimized to answer functional requirements by optimizing process parameters. This can be performed by linking process parameters to the resulting manufactured geometry. This paper deals with an original method for surface geometry characterization of printed parts (using Fused Filament Fabrication FFF) based on 3D Computer Tomography (CT) measurements. From 3D measured data, surface extraction is performed, giving a set of skin voxels corresponding to the internal and external part surface. A multi-scale analysis method is proposed to analyse the relative internal area of the total surface obtained at different scales (from sub-voxel to super-voxel scales) with different process parameters. This analysis turns out to be relevant for filling strategy discrimination.

Simulation of Laser-Sensor Digitizing for On-Machine Part Inspection

Integrating measurement operations for on-machine inspection in a 5-axis machine tool is a complex activity requiring a significant limitation of measurement time in order not to penalize the production time. When using a laser-plane sensor, time optimization must be done while keeping the quality of the acquired data. In this paper, a simulation tool is proposed to assess a given digitizing trajectory. This tool is based on the analysis of sensor configurations relatively to the geometry of the studied part.