Development of CAM Software to Achieve Automated NC Program Generation: Application to Machining From Near Net Shape Material

Author(s):  
Isamu Nishida ◽  
Keiichi Shirase

Abstract A method to automatically calculate tool paths and apply to machining from near net shape material is proposed. At first, this study proposes a contour line model, in which the product model is minutely divided on the plane along any one axial direction and the contour lines to show the cross section of the product is superimposed. Subsequently, this study proposes a method to calculate the tool positions according to the interference amount between product surface and tool. Furthermore, this study proposes the method to calculate tool paths for near net shape material. The case study was conducted to validate the effectiveness of the proposed method. As the result of this case study, it was confirmed that the proposed method can automatically generate the tool paths for near net shape. The machining efficiency from near net shape material will be better than that from box shape material. The results showed that the proposed method has good potential to perform customized manufacturing, and realize both high productivity and reliability in machining operation.

2020 ◽  
Vol 14 (3) ◽  
pp. 459-466 ◽  
Author(s):  
Isamu Nishida ◽  
◽  
Keiichi Shirase

A method to uniquely calculate the tool path and to modify the tool path during air cutting motion to reduce the machining time is proposed. This study presents a contour line model, in which the product model is minutely divided on a plane along an axial direction, and the contour line of the cross-section of the product is superimposed. A method is then proposed to calculate the tool position according to the degree of interference between the product surface and the tool. Furthermore, this study proposes a technique to reduce the machining time by tool path modification during air cutting motion. This is determined by the geometric relationship between the product surface and the tool, and not based on cutting simulations. A cutting experiment was conducted to validate the effectiveness of the proposed method. Based on the results, it was confirmed that the difference in machining time between the tool path with modification and the tool path without modification was large. Moreover, the machining time was significantly reduced by the tool path modification. The results showed that the proposed method has good potential to perform customized manufacturing, and to realize both high productivity and reliability in machining operation.


2011 ◽  
Vol 41 (5) ◽  
pp. 986-993 ◽  
Author(s):  
Carol A. Rolando ◽  
Michael S. Watt ◽  
Jerzy A. Zabkiewicz

Plantation forests certified by the Forest Stewardship Council have restrictions on herbicide use. Since certified plantations are dependant on herbicides for cost-effective vegetation management, compliance requires a shift from current chemical practices. Using New Zealand plantation forests as a case study, discounted cash flow analyses were used to estimate the cost of certification-compliant vegetation control regimes compared with current non-compliant methods. We examined methods that (i) reduce the quantity of herbicides by using spot control and (ii) avoid the use of herbicides by using weed mats, manual, and mechanical control. Cost analyses were undertaken for low-, medium-, and high-productivity sites. The internal rate of return of the non-compliant regime was between 5% and 5.8% across the productivity range. Spot control was cheaper than current non-compliant practice. However, spot control is limited by site suitability and the availability of labour. Non-chemical control methods were expensive relative to other regimes. Reductions in the internal rate of return varied across low- and high-productivity sites between 0.8% and 0.5% for manual control, 1.3% and 0.8% for mechanical control, and 1.7% and 1.0% for weed mats. Meeting the goals of certification while retaining cost-effective vegetation control presents a challenge to the plantation forestry sector.


Author(s):  
Yogi Baskoro ◽  
Indra Jaya ◽  
Wahyu Caesarendra ◽  
Andika Winardi ◽  
Erix Nugroho ◽  
...  
Keyword(s):  

Author(s):  
Jing Tao ◽  
Huanan Qian ◽  
Suiran Yu

The accuracy of machine is important to achieving highly accurate shapes. This paper is focused on mechanical design of highly accurate mechanical linkage servo press applicable to (near-)net shape forming. The effects of geometric errors, deformations under heavy loads and ram tilting are analyzed. A top-down design for accuracy approach is proposed: First, accuracy model for identification of inaccuracy-causing factors and their interlinking relations is developed. Then, based on this model, top accuracy index are decomposed and translated into structure design specifications at component level. Both analytic and simulation methods are employed for design for accuracy in aspects of dimensional and geometric tolerance allocation, stiffness synthesis and anti-eccentric load capability. A case study of mechanical design for accuracy of a six-linkage mechanical servo press is also presented to demonstrate and test the proposed design approaches.


Author(s):  
Stefan Wo¨lkl ◽  
Kristina Shea

The importance of the concept development phase in product development is contradictory to the level and amount of current computer-based support for it, especially with regards to mechanical design. Paper-based methods for conceptual design offer a far greater level of maturity and familiarity than current computational methods. Engineers usually work with software designed to address only a single stage of the concept design phase, such as requirements management tools. Integration with software covering other stages, e.g. functional modeling, is generally poor. Using the requirements for concept models outlined in the VDI 2221 guideline for systematic product development as a starting point, the authors propose an integrated product model constructed using the Systems Modeling Language (SysML) that moves beyond geometry to integrate all necessary aspects for conceptual design. These include requirements, functions and function structures, working principles and their structures as well as physical effects. In order to explore the applicability of SysML for mechanical design, a case study on the design of a passenger car’s luggage compartment cover is presented. The case study shows that many different SysML diagram types are suitable for formal modeling in mechanical concept design, though they were originally defined for software and control system development. It is then proposed that the creation and use of libraries defining generic as well as more complicated templates raises efficiency in modeling. The use of diagrams and their semantics for conceptual modeling make SysML a strong candidate for integrated product modeling of mechanical as well as mechatronic systems.


2016 ◽  
Vol 15 (2) ◽  
pp. 194
Author(s):  
D Dilahur ◽  
U Umrotun ◽  
P Priyono ◽  
Choirul Amin ◽  
M. Farid Aminudin

This study is carried out in Delanggu, Klaten, that has high productivity of rice but undergoing a decrease in the role of the sector of agriculture. The goal of this study is to observe young people departicipation in the sector od agriculture and fators that influence it. The method used is survey method. The population is all of the young people in Delanggu, 1.419 peoples. The sampling uses stratified proporsional quota sampling where respondents are divided into three groups of age, 15-19 years old, 20-24 years old, and 25-29 years old. Every sampling in eah group is taken 5% proportionally, with its homogenates consideration, while the characteristic, which has determined in order to fulfil the number of determined quota in each age group. Collected data is presented in the form of frequency and cross table. Qualitative data analysis uses logical thought, deducyive-inductive, analogy ang comparison, whereas analyzing frequency and cross table uses quantitative data analysis. The use of both analysis is adjusted to the data and goal of the study.


2021 ◽  
pp. 506-525
Author(s):  
Hai-Hoa Nguyen ◽  
Huy Duc Vu ◽  
Achim Röder

This study aimed to map the status of mangrove forests over the coasts of Hai Ha District and Mong Cai City in Quang Ninh Province by using 2019 Landsat-8 imagery. It then developed the AGB estimation model of mangrove forests based on the AGB estimation-derived plots inventory and vegetation indices-derived from Landsat-8 data. As results, there were five land covers identified, including mangrove forests, other vegetation, wetlands, built-up, and water, with the overall accuracy assessments of 80.0% and Kappa coefficient of 0.74. The total extent of mangrove forests was estimated at 4291.2 ha. The best AGB estimation model that was selected to estimate the AGB and AGC of mangrove forests for the whole coasts of Hai Ha District and Mong Cai City is AGB= 30.38 + 911.95*SAVI (R2=0.924, PValue <0.001). The model validation assessment has confirmed that the selected AGB model can be applied to Hai Ha and Mong Cai coasts with the mean difference between AGB observed and AGB predicted at 16.0 %. This satisfactory AGB model also suggests a good potential for AGB and AGC mapping, which offer the carbon trading market in the study site. As the AGB model selected, the total AGB and AGC of mangrove forests were estimated at about 14,600,000 tons and 6,868,076 tons with a range of from 94.0 - 432.0 tons ha-1, from 44.2 - 203.02 tons ha-1, respectively. It also suggests that the newly-developed AGB model of mangrove forests can be used to estimate AGC stocks and carbon sequestration of mangrove forests for C-PFES in over the coasts of Hai Ha District and Mong Cai City, which is a very importantly financial source for mangrove forest managers, in particular for local mangrove protectors.


Author(s):  
Ebrahim Mazharsolook ◽  
David C. Robinson ◽  
Jonathan D. Casey

Abstract Statistical methods are explored for the use in modelling of discrete manufacturing. The developed methodologies based on Design of Experiments (DOE) and stepwise regression to obtain the product model are described. This model is then embedded within a software system which is used for simulation of design changes, process changes and disturbances. The software is used to predict final test results in respect of up-stream parameter changes. A case study is presented o show the implementation of this method of modelling in Quality Control of manufacture. This case study has successfully been implemented. The system is currently assisting the company in design of similar product. Feasibility of applying Artificial Intelligen (AI) techniques to Model-Based Quality Control (MBQC) is investigated. An outline of the future development of Hybrid MBQC is then presented.


2021 ◽  
Vol 111 (06) ◽  
pp. 368-371
Author(s):  
Sebastian Greco ◽  
Marc Schmidt ◽  
Benjamin Kirsch ◽  
Jan C. Aurich

Additive Fertigungsverfahren zeichnen sich durch die Möglichkeit der endkonturnahen Fertigung komplexer Geometrien aus. Die geringe Produktivität etablierter Verfahren wie etwa dem Pulverbettverfahren hemmen aktuell den wirtschaftlichen Einsatz additiver Fertigung. Das Hochgeschwindigkeits-Laserauftragschweißen (HLA) soll durch deutlich erhöhte Auftragsraten und somit bisher unerreicht hoher Produktivität bei der additiven Fertigung dazu beitragen, deren Wirtschaftlichkeit zu steigern. &nbsp; Additive manufacturing enables the near-net-shape production of complex geometries. The low productivity of established processes such as powder bed processes is currently limiting the economic use of additive manufacturing. High-speed laser direct energy deposition (HS LDED) is expected to improve the economic efficiency of additive manufacturing by significantly increasing deposition rates and thus previously unattained high productivity.


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