Third-order chord error estimation for freeform contour in computer-aided manufacturing and computer numerical control systems

2018 ◽  
Vol 233 (3) ◽  
pp. 863-874 ◽  
Author(s):  
Xu Du ◽  
Jie Huang ◽  
Li-Min Zhu ◽  
Han Ding
Keyword(s):  
Control Systems ◽  
Computer Numerical Control ◽  
Second Order ◽  
Numerical Control ◽  
Machining Accuracy ◽  
Order Method ◽  
Third Order ◽  
Computer Aided Manufacturing ◽  
Chord Error ◽  
Computer Aided

The chord error employed in computer-aided manufacturing and computer numerical control systems is a crucial index to evaluate the machining accuracy of machined parts. It is usually estimated by the second-order method, that is, the osculating circle method. The second-order estimation only takes the curvature of the curve into account, which will bring about great estimation error when applying to freeform curves. In this article, a third-order method that estimates the chord error using conical helices is proposed. By investigating the geometric properties of the conical helix, it is found that there exists a conical helix that has third-order contact with the freeform curve. With the aid of this conical helix, a third-order model for estimating the chord error of freeform curves is developed. Numerical examples of three freeform curves are provided to verify the effectiveness of the proposed estimation model.

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.

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.

scholarly journals Accuracy of Implant Surgical Guides Fabricated Using Computer Numerical Control Milling for Edentulous Jaws: A Pilot Clinical Trial

2020 ◽  
Author(s):  
Jinyou Chai ◽  
Xiaoqian Liu ◽  
Ramona Schweyen ◽  
Jürgen Setz ◽  
Shaoxia Pan ◽  
...  
Keyword(s):  
Clinical Trial ◽  
Computer Numerical Control ◽  
Numerical Control ◽  
Cnc Milling ◽  
Implant Position ◽  
Surgical Guides ◽  
Computer Aided ◽  
Cad Cam ◽  
The Mean ◽  
Edentulous Jaws

Abstract Background To evaluate the accuracy of a computer-aided design and computer-aided manufacturing (CAD-CAM) surgical guide for implant placement in edentulous jaws. Methods Nine patients with twelve edentulous jaws seeking implants were recruited. Radiographic guides with diagnostic templates were fabricated from try-in waxup dentures. Planning software (Organical® Dental Implant, Berlin, Germany) was used to virtually design the implant positions, and the radiographic templates were converted into surgical guides using computer numerical control (CNC) milling. Following the guided implant surgery protocol, forty-four implants were placed into twelve edentulous jaws. Cone-beam computed tomography (CBCT) scans were performed post-operatively for each jaw, and the deviations between the planned and actual implant positions were measured. Results All 44 implants survived, and no severe haematomas, nerve injuries or unexpected sinus perforations occurred. The mean three dimensional linear deviation of implant position between virtual planning and actual placement was 1.53 ± 0.48 mm at the implant neck and 1.58 ± 0.4 mm at the apex. The angular deviation was 3.96 ± 3.05 degrees. The mean deviation between virtual and actual implant position was significantly smaller in the maxilla than in the mandible. No significant differences were found in the deviation of implant position between cases with and without anchor pins. Conclusions The guides fabricated using the CAD-CAM CNC milling technique provided comparable accuracy as those fabricated by Stereolithography. The displacement of the guides on edentulous arch might be the main contributing factor of deviation. Trial registration: Chinese Clinical Trial Registry, ChiCTR-ONC-17014159

The Development of a Profile-Milling Program for Teaching Computer-Aided-Manufacturing and CNC Programming

1997 ◽  
Author(s):  
Anthony Hotchkiss
Keyword(s):  
Computer Aided Design ◽  
Undergraduate Curriculum ◽  
Numerical Control ◽  
Computer Aided Manufacturing ◽  
Machining Center ◽  
Vertical Milling ◽  
Computer Aided ◽  
Cad Cam ◽  
Cnc Programming ◽  
Aided Design

Abstract At SUNY College at Buffalo, a new course, TEC302, CAD/CAM, computer-aided-design and computer-aided-manufacturing was added to the Industrial Technology (IT) undergraduate curriculum in the fall of 1994. At that time, the technology department had been using the AutoCAD system for design/drafting, and SmartCAM for demonstrating computer-aided-manufacturing. SmartCAM is a sophisticated product that takes a great deal of training to use, does not work directly in AutoCAD, and with only four licenses, was not available to all the students. For these reasons, the author developed a CAM program, VAL-CAM, that works inside AutoCAD, and has most of the aspects of a more sophisticated CAM program, yet is simpler to use, is available to all students, and automatically generates CNC (computer-numerical-control) code suitable for driving the departments’ vertical milling machining center. This paper discusses the development of VAL-CAM, which is written in the AutoLISP language for compatibility with AutoCAD. The dialogue control language (DCL) of AutoCAD was also used for part of the user interface for VALCAM. The algorithms, flow diagrams, pseudo code and actual LISP code for some of the more interesting parts of the program are presented. VAL-CAM is under continuous development, and later sections of the program will be discussed in future papers.

Feature-based automatic NC programming for aero-engine casings

2018 ◽  
Vol 233 (4) ◽  
pp. 1289-1301
Author(s):  
Nan Zhou ◽  
Xu Liu
Keyword(s):  
Manufacturing Systems ◽  
Numerical Control ◽  
Programming Approach ◽  
Programming System ◽  
Computer Aided Manufacturing ◽  
Nc Programming ◽  
Computer Aided ◽  
Aero Engine ◽  
Feature Based ◽  
Low Efficiency

Traditional numerical control (NC) programming methods based on commercial computer-aided manufacturing systems usually require a large number of manual interactions with high-skilled experience, which not only results in low efficiency but also unstable machining quality. Especially since the structural complexity and machining requirements keep increasing, the NC programming is becoming a bottleneck problem in machining complex parts like aero-engine casings. This article proposes a feature-based automatic NC programming approach for aero-engine casings. A machining feature classification towards the geometric and machining characteristics of aero-engine casings is given. Then, a feature-based method to extract machining regions by considering the alternatives in selecting turning or milling operations is discussed. After the construction of machining operations, an undercut region detection method is also presented to evaluate the interim machining effects reasoned by each individual machining operation for excessive cutting avoidance. By implementing the proposed approach, a feature-based NC programming system is developed on a commercial computer-aided manufacturing platform and a real aero-engine casing is chosen to demonstrate the feasibility of the proposed approach.

A Multi-Platform Compatible and Open Software Architecture for Computer Numerical Control Systems

2012 ◽  
Vol 468-471 ◽  
pp. 430-433
Author(s):  
Jing Jie Jiang ◽  
Hua Qing Tan ◽  
Bo Yao
Keyword(s):  
Software Architecture ◽  
Control Systems ◽  
Interface Layer ◽  
Computer Numerical Control ◽  
Numerical Control ◽  
Component Technology ◽  
Software Architectures ◽  
Business Logic ◽  
Data Layer ◽  
Business Layer

Abstract. By analyzing the current open software architectures for PC-based master-slave Computer Numerical Control(CNC) systems and soft-CNC systems, this paper put forward a multi-platform compatible open software architecture for the two types of CNC systems. The architecture is composed by five different function layers: CNC presentation Layer, CNC Business Layer, CNC Data Layer, NC Interface Layer and NCK Layer. Firstly, the WPF and the MVVM pattern decouple the User Interface (UI) presentation and business logic. Secondly, the component technology is used to decouple the business logic and Numerical Control(NC) functions. Thirdly, the implementation of NC tasks is put into non-RT environment and RT environment. The experiment results of developing the application based on the architecture show that the layered software architecture improves the maintenance and development efficiency, and running the application in the “non-RT+RT” environment proves that the architecture is available for PC-based master-slave CNC systems and soft-CNC systems.

An Integrated Methodology for the Teaching of Computer Aided Tools for Automated Machining

2011 ◽  
Vol 692 ◽  
pp. 8-15
Author(s):  
Pedro Jose Núñez López ◽  
Eustaquio García Plaza ◽  
Angel Ramon Martín ◽  
A. Egido
Keyword(s):  
Computer Aided Design ◽  
Mechanical Design ◽  
Computer Numerical Control ◽  
Numerical Control ◽  
Design Stage ◽  
Full Potential ◽  
Solid Modelling ◽  
Early Design ◽  
Early Design Stage ◽  
Computer Aided

To date a wide variety of computer aided tools are available for computer numerical controlled (CNC) automated machine-tools. Solid modelling software and 3D computer-aided design (CAD) are know firmly established in the early design stage whereas computer aided machining (CAM) and computer numerical control (CNC) simulator software is employed during the manufacturing stage. Training in the use of these systems is often undertaken in separate technical disciplines and training courses (e.g., graphic representation, mechanical design, computer numerical control programming, computer-aided machining, manufacturing technology, etc.), but students often lack a sound global understanding of these tools and fail to comprehend the full potential of integrating these applications. Thus, the aim is to propose a global methodology for the teaching of computer aided automated machining systems by integrating an array of computer aided tools (3D solid modelling, CAD/CAM software, CNC simulators, DNC communication, etc.) in order to enhance knowledge and develop skills of the entire manufacturing process i.e., to provide practical hands-on tasks from the early design stages to the final stages of the computer aided automated machining of a product.

scholarly journals Total talar prosthesis with and without ankle ligament reconstruction using the three-dimensional computer-aided design and computer numerical control manufacturing techniques

2020 ◽  
Vol 12 (3) ◽  
Author(s):  
Chayanin Angthong ◽  
Prasit Rajbhandari
Keyword(s):  
Computer Aided Design ◽  
Ligament Reconstruction ◽  
Three Dimensional ◽  
Computer Numerical Control ◽  
Numerical Control ◽  
Ankle Ligament ◽  
Computer Aided ◽  
The Mean ◽  
Aided Design

Severe damage and bone loss of the talus are problematic issues because of its unique shape, function, and characteristics. This present study’s objective is to propose the process of customized total talar prosthesis manufacturing, using three-dimensional (3D) Computer-Aided Design (CAD) with Computer Numerical Control (CNC) production along with evaluation of the results of total talar prosthesis replacement with or without ankle ligament reconstruction in patients with severe conditions of talus. The case series included five patients (mean age: 27.6 years) with severe talar loss or damage. The mean follow-up time was 17.8±8.4 months. Related complications were: i) mild subsidence in 1 patient (20%) and ii) periprosthetic fracture in another patient (20%). The mean clinical scores including VAS-FA and SF-36 were improved following surgeries. Customized total talar prosthesis appears to provide satisfactory outcomes for the treatment of severe talar loss or damage at a short-term follow-up.

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