scholarly journals Applying Rational Envelope curves for skinning purposes

2020 ◽  
Author(s):  
Kinga Kruppa
Keyword(s):  
Minkowski Space ◽  
Interpolation Method ◽  
Computer Numerical Control ◽  
Numerical Control ◽  
Application Area ◽  
Computer Aided Geometric Design ◽  
Numerical Control Machining ◽  
Novel Approach ◽  
Computer Aided ◽  
Pythagorean Hodograph

AbstractSpecial curves in the Minkowski space such as Minkowski Pythagorean hodograph curves play an important role in computer-aided geometric design, and their usages are thoroughly studied in recent years. Bizzarri et al. (2016) introduced the class of Rational Envelope (RE) curves, and an interpolation method for G1 Hermite data was presented, where the resulting RE curve yielded a rational boundary for the represented domain. We now propose a new application area for RE curves: skinning of a discrete set of input circles. We show that if we do not choose the Hermite data correctly for interpolation, then the resulting RE curves are not suitable for skinning. We introduce a novel approach so that the obtained envelope curves touch each circle at previously defined points of contact. Thus, we overcome those problematic scenarios in which the location of touching points would not be appropriate for skinning purposes. A significant advantage of our proposed method lies in the efficiency of trimming offsets of boundaries, which is highly beneficial in computer numerical control machining.

Inquiry-based learning: Development of an introductory manufacturing processes course based on a mobile inverted pendulum robot

2019 ◽  
Vol 48 (4) ◽  
pp. 371-390
Author(s):  
Junkun Ma ◽  
Keith Coogler ◽  
Minjae Suh
Keyword(s):  
Additive Manufacturing ◽  
Product Design ◽  
Inverted Pendulum ◽  
Computer Numerical Control ◽  
Numerical Control ◽  
Manufacturing Processes ◽  
Engineering Technology ◽  
Numerical Control Machining ◽  
Inquiry Based Learning ◽  
Computer Aided

This paper describes the development of an innovative introductory manufacturing processes course designed to expose students to a broad overview of fundamental concepts, methods, procedures, tools, and equipment used in the manufacturing industry. Based on an educational mobile inverted pendulum robot, students are introduced to product design and prototyping by identifying an existing problem with a component in the robot, redesigning the component using computer aided design software, and then building a prototype using additive manufacturing methods. Subsequently, a set of hypothetical design requirement changes is imposed, and various design methods and manufacturing processes that can be used to make components to satisfy these new requirements are discussed. Topics covered include integrated product design, additive manufacturing prototyping based on different technologies, plastic injection molding, sand casting, and fundamentals of both computer aided manufacturing and computer numerical control machining. Tools, fixtures, and accessories required in these processes, as well as associated challenges, are also discussed. This course adapts the inquiry-based learning active learning pedagogical approach and focuses on the development of students’ ability to conduct analytical analysis and to apply a knowledge of mathematics, science, engineering, and technology to solve practical engineering technology problems. As an introductory course designed to be offered to freshman level students, this course engages students in engineering technology related topics and stimulates their interest in manufacturing related subjects. It helps with improving the engineering student retention rate and serves as a pathway connecting students to more advanced specialized manufacturing courses such as computer numerical control machining technology. This paper presents course materials developed and student feedback as well as their evaluation of the course effectiveness based on a summative questionnaire-style survey from the first cohort of students.

scholarly journals Possibilities and Advantages of Rational Envelope and Minkowski Pythagorean Hodograph Curves for Circle Skinning

Mathematics ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 843
Author(s):  
Kinga Kruppa ◽  
Roland Kunkli ◽  
Miklós Hoffmann
Keyword(s):  
Minkowski Space ◽  
Geometric Design ◽  
Computer Aided Geometric Design ◽  
New Class ◽  
Computer Aided ◽  
Pythagorean Hodograph

Minkowski Pythagorean hodograph curves are widely studied in computer-aided geometric design, and several methods exist which construct Minkowski Pythagorean hodograph (MPH) curves by interpolating Hermite data in the R2,1 Minkowski space. Extending the class of MPH curves, a new class of Rational Envelope (RE) curve has been introduced. These are special curves in R2,1 that define rational boundaries for the corresponding domain. A method to use RE and MPH curves for skinning purposes, i.e., for circle-based modeling, has been developed recently. In this paper, we continue this study by proposing a new, more flexible way how these curves can be used for skinning a discrete set of circles. We give a thorough overview of our algorithm, and we show a significant advantage of using RE and MPH curves for skinning purposes: as opposed to traditional skinning methods, unintended intersections can be detected and eliminated efficiently.

scholarly journals Development of integrated intelligent computer-aided design system for mechanical power-transmitting mechanism design

2017 ◽  
Vol 9 (7) ◽  
pp. 168781401771038 ◽  
Author(s):  
Isad Saric ◽  
Adil Muminovic ◽  
Mirsad Colic ◽  
Senad Rahimic
Keyword(s):  
Rapid Prototyping ◽  
Computer Aided Design ◽  
Three Dimensional ◽  
Computer Numerical Control ◽  
Numerical Control ◽  
Mechanical Power ◽  
Design System ◽  
Computer Aided ◽  
Aided Design ◽  
Intelligent Computer

This article presents architecture of integrated intelligent computer-aided design system for designing mechanical power-transmitting mechanisms (IICADkmps). The system has been developed in C# program environment with the aim of automatising the design process. This article presents a modern, automated approach to design. Developed kmps modules for calculation of geometrical and design characteristics of mechanical power-transmitting mechanisms are described. Three-dimensional geometrical parameter modelling of mechanical power-transmitting mechanisms was performed in the computer-aided design/computer-aided manufacturing/computer-aided engineering system CATIA V5. The connection between kmps calculation modules and CATIA V5 modelling system was established through initial three-dimensional models – templates. The outputs from the developed IICADkmps system generated final three-dimensional virtual models of mechanical power-transmitting mechanisms. Testing of the developed IICADkmps system was performed on friction, belt, cogged (spur and bevel gears) and chain transmitting mechanisms. Also, connection of the developed IICADkmps system with a device for rapid prototyping and computer numerical control machines was made for the purpose of additional testing and verification of practical use. Physical prototypes of designed characteristic elements of mechanical power-transmitting mechanisms were manufactured. The selected test three-dimensional virtual prototypes, obtained as an output from the developed IICADkmps system, were manufactured on the device for rapid prototyping (three-dimensional colour printer Spectrum Z510) and computer numerical control machines. Finally, at the end of the article, conclusions and suggested possible directions of further research, based on theoretical and practical research results, are presented.

Parallel acceleration/deceleration feedrate scheduling for computer numerical control machine tools based on bi-directional scanning technique

2017 ◽  
Vol 233 (3) ◽  
pp. 937-947 ◽  
Author(s):  
Jie Huang ◽  
Xu Du ◽  
Li-Min Zhu
Keyword(s):  
Computer Numerical Control ◽  
Numerical Control ◽  
Processing Unit ◽  
Numerical Control Machining ◽  
Computational Burden ◽  
Central Processing ◽  
Scanning Process ◽  
Scanning Technique ◽  
Feedrate Scheduling ◽  
Parallel Acceleration

The acceleration/deceleration feedrate scheduling is one of the most important techniques in computer numerical control systems. Along with this technique, the bi-directional scanning technique is always employed. The bi-directional scanning technique consists of a backward scanning process followed by a forward scanning process. The two scanning processes in the conventional methods are executed in a serial manner by scanning through all the scheduling blocks one by one. Consequently, the feedrate scheduling will suffer from a heavy computational burden when there are massive blocks to be scanned, which deteriorates its real-time performance for computer numerical control machining. To alleviate the computational burden, a parallel acceleration/deceleration feedrate scheduling approach is proposed in this article. With this method, the scheduling blocks are splitted into several scheduling units and the feedrate for each of them is scheduled simultaneously. The feasibility of the proposed approach is validated through the feedrate scheduling for two widely used butterfly and helix paths. For a constructed example of feedrate scheduling, a significant acceleration ratio about 3.7 on a personal computer with a quad-core central processing unit is achieved.

scholarly journals Digital twin control of multi-axis wood CNC machining center based on LinuxCNC

BioResources ◽  
2020 ◽  
Vol 16 (1) ◽  
pp. 1115-1130
Author(s):  
Aleksandar Rakic ◽  
Sasa Zivanovic ◽  
Zoran Dimic ◽  
Mladen Knezevic
Keyword(s):  
Control System ◽  
Virtual Machines ◽  
Computer Numerical Control ◽  
Cnc Machining ◽  
Numerical Control ◽  
Machining Process ◽  
Programming System ◽  
Digital Twin ◽  
Machining Center ◽  
Computer Aided

This paper presents an application of an open architecture control system implemented on a multi-axis wood computer numerical control milling machining center, as a digital twin control. The development of the digital twin control system was motivated by research and educational requirements, especially in the field of configuring a new control system by “virtual commissioning”, enabling the validation of the developed controls, program verification, and analysis of the machining process and monitoring. The considered wood computer numerical control (CNC) machining system is supported by an equivalent virtual machine in a computer-aided design and computer-aided manufacturing (CAD/CAM) environment, as well as in the control system, as a digital twin. The configured virtual machines are used for the verification of the machining program and programming system via machining simulation, which is extremely important in multi-axis machining. Several test wood workpieces were machined to validate the effectiveness of the developed control system based on LinuxCNC.

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