scholarly journals Flat-end tool orientation based on rotation-minimizing frame

2019 ◽  
Vol 7 (3) ◽  
pp. 257-269 ◽  
Author(s):  
Xiang Zou ◽  
Hon-Yuen Tam ◽  
Hai-Yin Xu ◽  
Ke Shi
Keyword(s):  
Tool Orientation ◽  
Rotation Minimizing Frame

Robot Trajectory Planning Using Rational Frenet-Serret Curves

Volume 2 ◽  
2004 ◽  
Author(s):  
Reza Ravani ◽  
Ali Meghdari
Keyword(s):  
Trajectory Planning ◽  
Computer Animation ◽  
Rational Curves ◽  
Robot Arm ◽  
Robot Trajectory ◽  
Arm Motion ◽  
Sweep Surface ◽  
And Robotics ◽  
Rotation Minimizing Frame ◽  
Robot Trajectory Planning

The aim of this paper is to demonstrate that the techniques of Computer Aided Geometric Design such as spatial rational curves and surfaces could be applied to Kinematics, Computer Animation and Robotics. For this purpose we represent a method which utilizes a special class of rational curves called Rational Frenet-Serret (RF) [8] curves for robot trajectory planning. RF curves distinguished by the property that the motion of their Frenet-Serret frame is rational. We describe an algorithm for interpolation of positions by a rational Frenet-Serret motion. Further more we provide an analysis on spatial frames (Frenet-Serret frame and Rotation Minimizing frame) for smooth robot arm motion and investigate their applications in sweep surface modeling.

Trajectory Planning for Conformal 3D Printing Using Non-Planar Layers

2018 ◽  
Author(s):  
Aniruddha V. Shembekar ◽  
Yeo Jung Yoon ◽  
Alec Kanyuck ◽  
Satyandra K. Gupta
Keyword(s):  
Additive Manufacturing ◽  
Trajectory Planning ◽  
Industrial Robots ◽  
Complex Geometries ◽  
Robot Arm ◽  
Joint Movement ◽  
Tool Orientation ◽  
3D Objects ◽  
Planar Surfaces ◽  
Build Time

Additive manufacturing (AM) technologies have been widely used to fabricate 3D objects quickly and cost-effectively. However, building parts consisting of complex geometries with multiple curvatures can be a challenging process for the traditional AM system whose capability is restricted to planar-layered printing. Using 6-DOF industrial robots for AM overcomes this limitation by allowing materials to deposit on non-planar surfaces with desired tool orientation. In this paper, we present collision-free trajectory planning for printing using non-planar deposition. Trajectory parameters subject to surface curvature are properly controlled to avoid any collision with printing surface. We have implemented our approach by using a 6-DOF robot arm. The complex 3D structures with various curvatures were successfully fabricated, while avoiding any failures in joint movement, holding comparable build time and completing with a satisfactory surface finish.

scholarly journals Investigation into Hand Scraping: A Microanalysis

2018 ◽  
Vol 2 (4) ◽  
pp. 76 ◽  
Author(s):  
Kai Oßwald ◽  
Ingo Lochmahr ◽  
Yasin Bagci ◽  
Peter Saile
Keyword(s):  
Inertial Measurement Unit ◽  
Three Dimensional ◽  
Movement Pattern ◽  
Measurement Unit ◽  
Surface Finishing ◽  
Future Research ◽  
Tool Orientation ◽  
Inertial Measurement ◽  
Finishing Process ◽  
Basic Characteristics

Hand scraping is a manual surface finishing process that, despite its low productivity and high cost, is still applied in many industries because of its advantages concerning accuracy and tribology. In the presented microanalysis forces, movement patterns and tool orientation of individual hand scraping strokes were measured using a test stand, specifically designed for this purpose. It utilizes a camera, a three dimensional dynamometer, and an inertial measurement unit (IMU). The results show the basic characteristics of hand scraping. Typical courses of relevant quantities like cutting force, passive force, clearance, and directional angle are shown. In addition, the movement pattern of the tool during individual scraping strokes is analyzed. This research aims to contribute to a later implementation of automated scraping. The conducted research creates a base for future research regarding different scraping methods and achieved results.

An Analytical C3 Continuous Local Corner Smoothing Algorithm for Four-Axis Computer Numerical Control Machine Tools

2018 ◽  
Vol 140 (5) ◽  
Author(s):  
Qin Hu ◽  
Youping Chen ◽  
Jixiang Yang ◽  
Dailin Zhang
Keyword(s):  
Machine Tools ◽  
Numerical Control ◽  
Cnc Machine Tools ◽  
Smoothing Algorithm ◽  
Linear Motion ◽  
Tool Orientation ◽  
Cnc Machine ◽  
B Splines ◽  
Rotary Axes ◽  
Tip Position

Linear motion commands of multi-axis computer numerical control (CNC) machine tools need to be smoothed at the transition corners, because the velocity discontinuities at corners can result in fluctuations on machine tool motions and lead to poor surface quality. However, no research has been reported on local corner smoothing algorithm for four-axis CNC machine tools with two rotary axes by considering their special kinematic characteristics. To this end, this paper proposes an analytical C3 continuous local corner smoothing algorithm for four-axis CNC machines with two rotary axes. After coordinates transformation, the tool tip positions and tool orientations are smoothed by locally inserting specially designed three-dimensional (3D) quintic B-splines and one-dimensional (1D) quintic B-splines into the corners between linear motion segments, respectively. The smoothing algorithm guarantees C3 continuity of the tool tip position and C3 continuous synchronization of the tool orientation related to the tool tip position, through analytically evaluating control points of the inserted microsplines. The maximum error tolerances of the tool tip position and tool orientation are mathematically constrained. Experiments on an in-house developed four-axis machine verify the efficacy of the proposed algorithm, where maximal errors caused by the local corner smoothing algorithm are constrained, the synchronization of the tool orientation and the tool tip position are achieved, and the proposed C3 continuous corner smoothing algorithm has lower jerk and jounce but higher tracking and contour accuracy than C2 continuous algorithm.

Development of a System to Generate Tool Orientation Information for Positional 5-Axis Machining of Die and Mold

2008 ◽  
Vol 5 (1-4) ◽  
pp. 434-441 ◽  
Author(s):  
J. G. Lee ◽  
S. J. Yang ◽  
Y. H. Cho ◽  
S. K. Yoo ◽  
J. W. Park
Keyword(s):  
Tool Orientation ◽  
Orientation Information ◽  
Die And Mold

Analytical Method for Obtaining Cut Geometry of Helical Toroidal Cutter during Semi-Finish in 5-Axis Milling

2014 ◽  
Vol 541-542 ◽  
pp. 780-784 ◽  
Author(s):  
Gandjar Kiswanto ◽  
Hendriko Hendriko ◽  
Emmanuel Duc
Keyword(s):  
Analytical Method ◽  
Free Form ◽  
Machining Simulation ◽  
Tool Orientation ◽  
Essential Information ◽  
Simulation And Optimization ◽  
Helical Angle ◽  
Toroidal Cutter

Cut geometry data is an essential information in current machining simulation and optimization. The tool orientation changed continuously during free-form machining become a challenge in predicting cut geometry in 5-axis milling. This paper present an extended analytical method to define cut geometry during semi-finish milling. The algorithm was developed by taken into account the existence of helical angle. The developed model was successfully implemented to generate the shape and the length of cut. From the test it was found that helical angle gives significant effect to the cut geometry.

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