Application of the GWPS for Machining of a Transmission Housing

2000 ◽  
Author(s):  
Suren B. Rao ◽  
Gary L. Neal ◽  
Edward C. DeMeter ◽  
Martin W. Trethewey
Keyword(s):  
Reference Frame ◽  
Surface Current ◽  
Prototype System ◽  
Specific Information ◽  
Accuracy And Precision ◽  
Machining System ◽  
Housing Component ◽  
Set Up ◽  
Novel Concept ◽  
Machining Operations

Abstract One component of a modern machining system that has remained virtually unchanged, since time immemorial, is part location. The fundamental basis of current methods of part location is the concept of a physical datum surface, which is created in the first machining operation and conducting all the further machining operations with reference to this physical surface. Current workpiece positioning practice utilizes physical contacts between the fixture and workpiece for location. Due to contact feature variations, the positioning is inconsistent and variable for sequential machining set-ups. Consequently, geometric errors are induced in machined features. This paper proposes a novel concept, the Global Workpiece Positioning System (GWPS), for datum establishment. Precision artifacts are strategically located on the rough workpiece and a part reference frame is defined, with respect to these artifacts, at a qualification station. This part specific information now travels with the part to the machining station. At the machining station a probe is used to locate the artifacts on the part and determine their location with reference to the machine tool’s reference frame. Since the part reference frame is known with respect to the artifacts, its location can be derived with respect to the machine tool’s reference frame. The part program can then be modified to reflect the actual location of the part and the machining of the features carried out with a greater degree of accuracy and precision. A prototype system using the GWPS concept is implemented and presented. Experimental results validate the GWPS concept. A three-hole pattern is drilled and bored in an aircraft transmission housing component in a two set up operation. The GWPS located workpieces retained a hole center location accuracy within the required drawing specification without the use of the traditional location fixtures that are typically used for the two operational set-ups.

Development of STEP-NC Based Machining System for Machining Process Information Flow

2013 ◽  
Vol 315 ◽  
pp. 278-282
Author(s):  
Noordiana Kassim ◽  
Yusri Yusof ◽  
Mahmod Abd Hakim Mohamad ◽  
Mohd Najib Janon ◽  
Rafizah Mohd Hanifa
Keyword(s):  
Information Flow ◽  
Machining Process ◽  
Planning System ◽  
Specific Information ◽  
Cad Model ◽  
Machining Feature ◽  
Process Planning System ◽  
Depth Study ◽  
Cad Cam ◽  
Machining System

To realize the STEP-NC based machining system, it is necessary to perform machining feature extraction, generating machine-specific information, and creating a relationship between STEP-NC entities. A process planning system of a STEP-NC information flow that starts with constructing a machining feature from a CAD model will be developed. In this paper, a further in-depth study of the implementation and adaptation of STEP-NC in manufacturing is studied. This study will help to understand how the data from CAD/CAM can be converted into STEP-NC codes and the machining process will be based on the STEP-NC codes generated.

Parallel-Process (Simultaneous) Machining and its Stability

1999 ◽  
Author(s):  
O. Burak Ozdoganlar ◽  
William J. Endres
Keyword(s):  
Initial Conditions ◽  
General System ◽  
Parallel Process ◽  
Analytical Stability ◽  
Multiple Processes ◽  
Or Practice ◽  
Machining System ◽  
Eigenvector Analysis ◽  
The Stability ◽  
Machining Operations

Abstract This paper presents a mathematical perspective, to complement the intuitive or practice-oriented perspective, to classifying machining operations as parallel-process (simultaneous) or single-process in nature. Illustrative scenarios are provided to demonstrate how these two perspectives may lead in different situations to the same or different conclusions regarding process parallelism. A model representation of a general parallel-process machining system is presented, based on which the general parallel-process stability eigenvalue problem is formulated. For a special simplified case of the general system, analytical methods are employed to derive a fully analytical stability solution. Thorough study of this solution through eigenvector analysis sheds light on some fundamental phenomena of parallel-process machining stability, such as dependence of the stability solution on phasing of the initial conditions (disturbances). This establishes the importance, when employing numerical time-domain simulation for such analyses, of specifying initial conditions for the multiple processes to be arbitrarily phased so that correct results are achieved across all spindle speeds.

An Approach for Efficient CFD Simulations of an Ejector Air Injection System for Active Aerodynamic Compressor Stabilization

2017 ◽  
Author(s):  
Sebastian Brehm ◽  
Felix Kern ◽  
Jonas Raub ◽  
Reinhard Niehuis
Keyword(s):  
Large Scale ◽  
Armed Forces ◽  
Air Injection ◽  
Injection System ◽  
Cfd Simulations ◽  
Data Set ◽  
Numerical Effort ◽  
Enhance Efficiency ◽  
Set Up ◽  
Novel Concept

The Institute of Jet Propulsion at the University of the German Federal Armed Forces Munich has developed and patented a novel concept of air injection systems for active aerodynamic stabilization of turbo compressors. This so-called Ejector Injection System (EIS) utilizes the ejector effect to enhance efficiency and impact of the aerodynamic stabilization of the Larzac 04 two-spool turbofan engine’s LPC. The EIS design manufactured recently has been subject to CFD and experimental pre-investigations in which the expected ejector effect performance has been proven and the CFD set-up has been validated. Subsequently, optimization of the EIS ejector geometry comes into focus in order to enhance its performance. In this context, CFD parameter studies on the influence of in total 16 geometric and several aerodynamic parameters on the ejector effect are required. However, the existing and validated CFD set-up of the EIS comprises not only the mainly axisymmetric ejector geometry but also the highly complex 3D supply components upstream of the ejector geometry. This is hindering large scale CFD parameter studies due to the numerical effort required for these full 3D CFD simulations. Therefore, an approach to exploit the overall axissymmetry of the ejector geometry is presented within this paper which reduces the numerical effort required for CFD simulations of the EIS by more than 90%. This approach is verified by means of both experimental results as well as CFD predictions of the full 3D set-up. The comprehensive verification data set contains wall pressure distributions and the mass flow rates involved at various Aerodynamic Operating Points (AOP). Furthermore, limitations of the approach are revealed concerning its suitability e.g. to judge the response of the attached compressor of future EIS designs concerning aerodynamic stability or cyclic loading.

Pneumatic and similar breakwaters

1955 ◽  
Vol 231 (1187) ◽  
pp. 457-466 ◽  
Keyword(s):  
Small Amplitude ◽  
Wave Motion ◽  
Surface Current ◽  
Water Velocity ◽  
Air Injection ◽  
Air Bubbles ◽  
Surface Currents ◽  
Damping Effect ◽  
Water Jets ◽  
Set Up

The process of calming waves by injecting air bubbles beneath the surface has been known to civil engineers for nearly 50 years. It has been little used for its results have been erratic, its method of working was unknown and its effect could not be predicted. The investigation described in this paper has shown that the surface currents set up by air injection, and the distribution of the water velocity within the currents, can be matched by currents set up by water jets, and that the two currents so matched have almost the same wave-damping effect whether they are set up by water jets or by air. It is concluded that the bubbles as such have at most a very small effect on the wave motion. It is found that waves of small amplitude are stopped in the way predicted theoretically, but that as the amplitude increases the surface current necessary to stop waves of a given length increases.

Small Cattle for Small Farms

2008 ◽  
Author(s):  
Margo Hayes
Keyword(s):  
Prior Experience ◽  
Specific Information ◽  
Small Farms ◽  
Small Farm ◽  
Beef Industry ◽  
Set Up ◽  
The Many ◽  
Stocking Rates

There are more small farms in Australia than there are large, and this trend continues as an increasing number of larger farms are subdivided into smaller parcels. A growing demand for lifestyle blocks, in Australia and overseas, is fuelling an interest in the quieter, smaller breeds of cattle which have particular appeal as they are more manageable to control and maintain. Small Cattle for Small Farms is ideal for those people considering buying a small farm for lifestyle or commercial purposes. Written in response to the many questions the author was asked by those seeking to purchase small cattle, this practical and easy to understand guide provides an excellent introduction to small farming. The book assumes no prior experience with cattle, and covers all the basics to help you set up your small farm, including: types of cattle available, how to select your stock and care for them, stocking rates, fencing needs, vaccination requirements, methods of identification, and government requirements for land and stockowners. For those wishing to show their cattle, there is a chapter explaining how to prepare for competitions. A section on marketing details how to make a successful entry into the commercial beef industry, and a list of cattle organisations directs readers to more specific information for their chosen breeds.

Error Compensation of a NC Machining System Based on a Dynamic Feedback Neural Network

2011 ◽  
Vol 52-54 ◽  
pp. 1890-1894 ◽  
Author(s):  
Huang Lin Zeng ◽  
Yong Sun ◽  
Xiao Hong Ren ◽  
Li Xin Liu
Keyword(s):  
Neural Network ◽  
Error Compensation ◽  
Nc Machining ◽  
Machining Process ◽  
Dynamic Feedback ◽  
Machining System ◽  
Nc Machine ◽  
Feedback Neural Network ◽  
Set Up ◽  
Errors Analysis

Machining error of a NC machining system is a kind of comprehensive error in dynamically machining process; especially it is of errors with non-linear characteristics. In this paper, we will set up a kind of model of comprehensive errors analysis for a NC machining system and present an error compensation for high-precision a NC machining system by a dynamic feedback neural network embedded in a NC machine tool. The results obtained shows that this approach can effectively improve compensation precision and real time of error compensation on machine tools.

Fabrication Technology of Involute Micro Gear Based on Two-Photon of Femtosecond Laser

2010 ◽  
Vol 44-47 ◽  
pp. 670-674 ◽  
Author(s):  
Shu Feng Sun
Keyword(s):  
Femtosecond Laser ◽  
Light Source ◽  
Single Photon ◽  
Three Dimensional ◽  
Photon Absorption ◽  
Micro Electro Mechanical Systems ◽  
Excitation Light ◽  
Two Photon ◽  
Machining System ◽  
Set Up

Microfabrication is a kind of critical technology for the development of Micro Electro-Mechanical Systems (MEMS). The frequently-used microfabrication technologies are electric discharge machining, photoetching, LIGA and laser fabrication, et al. Micro structures may be fabricated by these technologies. The polymerization principle of two-photon of femtosecond laser is different from that of single-photon. Photoinitiator of photosensing material absorbs two photons simultaneously to accomplish energy level transition and to induce the material to occur photochemical reaction. For the material absorbing two photons, the energy of each photon is equivalent to half of the energy that needed by the material transiting from ground state to excited state. It is also equal to half of the energy needed by the material occurring single-photon absorption. Therefore, the photonic frequency of two-photon excitation light source is half of the single-photon light source. According to two-photon fabrication principle, machining system of two-photon of femtosecond laser is set up. Which includes light path transmission equipment, three dimensional micro displacement scanning stage and control software, et al. Involute micro gear is fabricated by two-photon of femtosecond laser generated by the system.

Study on Location Based Services Driven Mobile E-Commerce System

2013 ◽  
Vol 734-737 ◽  
pp. 3214-3219
Author(s):  
Hai Dong Zhong ◽  
Ping Li ◽  
Shao Zhong Zhang ◽  
Wen Ting Yuan ◽  
Xu Dong Zhao ◽  
...  
Keyword(s):  
Mobile Devices ◽  
Mobile Device ◽  
Location Based Services ◽  
Prototype System ◽  
Security Risks ◽  
Privacy And Security ◽  
Positioning Accuracy ◽  
Business Markets ◽  
Key Issues ◽  
Novel Concept

With the tremendous advances in mobile computing and communication capabilities, rapid proliferation of mobile devices, increasing powerful functions, and decreasing device costs, we are seeing a explosively growth in mobile e-commerce in various consumer and business markets. On the basis of analyzing demands of both buyers and seller in mobile e-commerce, the paper put forward a novel concept and technological framework of Location Based Services (LBS) driven mobile e-commerce. Some LBS related functions, in mobile device terminal, of the prototype system based on the architecture put forward are implemented. Also, some key issues of LBS based mobile e-commerce, such as positioning accuracy and new privacy and security risks, are discussed in detail.

Research on Surface Machining System for Light Metal Thin-Walled Parts Based on Spherical Coordinate

2010 ◽  
Vol 97-101 ◽  
pp. 1841-1844
Author(s):  
Shi Huan Wang ◽  
Zhi Gang Cai ◽  
Li Fang Lin
Keyword(s):  
Light Metal ◽  
Interpolation Algorithm ◽  
Spherical Coordinate ◽  
Surface Machining ◽  
Spiral Path ◽  
System A ◽  
Machining System ◽  
Thin Walled ◽  
Set Up

Surface machining system based on spherical coordinate is present for the large thin-walled director sphere part turning, to improve the efficiency and quality of part machining. In this system, a thickness surface B-spline model is set up based on spherical coordinates, the space spiral path generation method is planned, row spacing angle is determined by scallop height and blunt radius of cutting tool, and back cutting depth optimization treatment and space spiral interpolation algorithm are present.

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