MSc dissertation proposal 2014/2015

 

Interpolators for Computer Controlled Machines

 

 

Introduction:

 

Computer Numeric Control (CNC) machines can be controlled directly [Yaman13]. However, the most common situation is that a host computer produces motion commands for the machine, and the machine interprets the motion commands by interpolating the given via points [Farouki14]. G-coding (RS-274) is the oldest commanding language, and still the most commonly found in CNC machines, but is in essence limited to the specification of lines and arcs. More general curves, e.g. parametric curves as B-Splines and NURBS, only recently started to be adopted in high-end CNC machines [Hu09]. There is however a large amount of work to be done to allow the technology to be well integrated into most of the CNC machines.

 

 

Objectives:

 

The main objective of this work is the revision of older interpolation methodologies, as the Digital Data Analyser (DDA), and the proposal of novel interpolation methodologies which can be effective for example NURBS. Interpolation can be designed to work both for single or multiple axis CNC machines, in which case inverse kinematics needs to be involved.

 

 

Detailed description:

 

Interpolation is found in many domains of technology. For example rendering in graphics cards has seen impressive results in the last two decades. Interpolation research and development, within the printers and CNC machining domains, evolve at a slower pace. In particular a number of numerical interpolation modalities found in standard simulation tools, e.g. Matlab/Simulink, are yet to be thought for CNC. In this work is proposed the study of Non-Uniform Ration B-Splines (NURBS) in the vein of their rendering, i.e. their sampling (discretization) and interpolation.

 

The work is therefore organized in the following main steps:

- Do a historical research on DDA

- Study and simulation of DDA

- Study on parametric curves and inverse kinematics

- Simulation of the rendering of NURBS

 

 

References:

 

[Yaman13] "Direct command generation for CNC machinery based on data compression techniques", U. Yaman, M. Dolen, Robotics and Computer-Integrated Manufacturing 29 (2013) 344–356

 

[Hu09] "An Adaptive Real-time NURBS Interpolator for CNC Machine Tools", H. Hu and X.T. Zhang, 2009 IEEE/ASME International Conference on Advanced Intelligent Mechatronics, 2009

 

[Farouki14] "Inverse kinematics for optimal tool orientation control in 5-axis CNC machining", Rida T. Farouki, Chang Yong Han,ShiqiaoLi, Computer Aided Geometric Design 31 (2014) 13–26

 

 

Requirements (grades, required courses, etc):

-

 

Expected results:

 

At the end of the work, the students will have enriched their experience in robot kinematics, control and interpolation.

 

 

Place for conducting the work-proposal:

ISR / IST

 

 

 

More MSc dissertation proposals on Computer and Robot Vision in:

 

http://omni.isr.ist.utl.pt/~jag