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51.
In reverse engineering, geometrical information of a product is obtained directly from a physical shape by a digitizing device. To fabricate the product, manufacturing information (usually tool-path) must be generated from a CAD model. The data digitized must be processed and in most cases, a surface model is constructed from them using some of the surface fitting technologies. However, these technologies are usually complicated and the process for constructing a surface patch from a massive digitizing data is time-consuming. To simplify the process for getting tool-path information, a simple algorithm is proposed in this paper. The algorithm is used to generate a 5-axis machining tool-path. Instead of implementing any complicated surface fitting techniques, a direct method is proposed for constructing three-dimensional (3D) triangular mesh from the digitizing data with the mesh points considered as the tool contact locations. Depending on the locations of the points digitized, a decimation procedure is applied such that some of the digitizing data will be filtered out. Then, the tool axis orientations which must be determined in 5-axis tool-path are calculated and the tool center locations are determined accordingly. A 3D biarc fitting technique is applied for all the tool center locations so that a complete 5-axis tool-path is obtained. 相似文献
52.
Application of artificial neural network for determination of standard time in machining 总被引:1,自引:1,他引:0
Izabela Kutschenreiter-Praszkiewicz 《Journal of Intelligent Manufacturing》2008,19(2):233-240
The purpose of this article is to present the application of neural network for time per unit determination in small lot production
in machining. A set of features considered as input vector and time consumption in manufacturing process was presented and
treated as output of the neural net. A neural network was used as a machining model. Sensitivity analysis was made and proper
topology of neural network was determined. 相似文献
53.
为解决电主轴因内部温度场复杂而造成冷却效果差的问题,设计了一种用于电主轴冷却的水冷机系统。根据电主轴热特性分析结果,提出了水冷机冷却方案,计算了相关的传热参数,并建立了电主轴温度-流速控制模型。然后,利用ANSYS Fluent软件对电主轴进行了流体冷却有限元仿真,并通过电主轴冷却实验对仿真结果进行了验证。通过对比仿真结果和实验结果可知,冷却后电主轴电机定子最高温度约下降了60%,转轴的形变量约降低了70%。结果表明:利用水冷机系统对电主轴进行冷却具有良好的冷却效果,这可为高精密机床主动热控制技术的研究提供一定的借鉴和参考。 相似文献
54.
介绍一种采用 STEWART机构的新型加工中心 .对这种加工中心加工球面时各“腿”长度变化的规律进行了分析 .结果表明 :各“腿”长度呈正 (余 )弦规律变化 ,且其变化周期与幅度均相同 ;它们的变化曲线依次相差 1 2 0°到达峰顶 ,其顺序与加工球面上截面圆各点的逆时针顺序相互对应 .导出的各“腿”长度变化的公式可用于指导数控编程 相似文献
55.
Recent evolutions on forging process induce more complex shape on forging die. These evolutions, combined with High Speed Machining (HSM) process of forging die lead to important increase in time for machining preparation. In this context, an original approach for generating machining process based on machining knowledge is proposed in this paper. The core of this approach is to decompose a CAD model of complex forging die in geometrical features. Technological data and topological relations are aggregated to a geometrical feature in order to create machining features. Technological data, such as material, surface roughness and form tolerance are defined during forging process and dies design. These data are used to choose cutting tools and machining strategies. Topological relations define relative positions between the surfaces of the die CAD model. After machining features identification cutting tools and machining strategies currently used in HSM of forging die, are associated to them in order to generate machining sequences. A machining process model is proposed to formalize the links between information imbedded in the machining features and the parameters of cutting tools and machining strategies. At last machining sequences are grouped and ordered to generate the complete die machining process. In this paper the identification of geometrical features is detailed. Geometrical features identification is based on machining knowledge formalization which is translated in the generation of maps from STL models. A map based on the contact area between cutting tools and die shape gives basic geometrical features which are connected or not according to the continuity maps. The proposed approach is illustrated by an application on an industrial study case which was accomplished as part of collaboration. 相似文献
56.
A genetic algorithm-based artificial neural network model for the optimization of machining processes 总被引:5,自引:2,他引:3
Artificial intelligent tools like genetic algorithm, artificial neural network (ANN) and fuzzy logic are found to be extremely
useful in modeling reliable processes in the field of computer integrated manufacturing (for example, selecting optimal parameters
during process planning, design and implementing the adaptive control systems). When knowledge about the relationship among
the various parameters of manufacturing are found to be lacking, ANNs are used as process models, because they can handle
strong nonlinearities, a large number of parameters and missing information. When the dependencies between parameters become
noninvertible, the input and output configurations used in ANN strongly influence the accuracy. However, running of a neural
network is found to be time consuming. If genetic algorithm-based ANNs are used to construct models, it can provide more accurate
results in less time. This article proposes a genetic algorithm-based ANN model for the turning process in manufacturing Industry.
This model is found to be a time-saving model that satisfies all the accuracy requirements. 相似文献
57.
58.
Olivier Kerbrat Pascal Mognol Jean-Yves HascoëtAuthor vitae 《Computers in Industry》2011,62(7):684-692
Design for manufacturing (DFM) approaches aim to integrate manufacturability aspects during the design stage. Most of DFM approaches usually consider only one manufacturing process, but product competitiveness may be improved by designing hybrid modular products, in which products are seen as 3-D puzzles with modules realized individually by the best manufacturing process and further gathered. A new DFM system is created in order to give quantitative information during the product design stage of which modules will benefit in being machined and which ones will advantageously be realized by an additive process (such as Selective Laser Sintering or laser deposition). A methodology for a manufacturability evaluation in case of a subtractive or an additive manufacturing process is developed and implemented in a CAD software. Tests are carried out on industrial products from automotive industry. 相似文献
59.
介绍了以MATLABV5 2为平台开发的盘 /轴系统瀑布图的仿真程序 ,仿真的结果可为设计和调整系统参数提供直观 ,可靠的依据。 相似文献
60.
介绍了一种用于数控车床的精确主轴定位准停的实用方法,数控系统发出M19命令给单片机8031系统。单片机系统通过接收主轴位置编码器的反馈信号,并计算后发出1个模拟量控制主轴驱动系统,主轴减速并稳定到设定值,当主轴运行到预设的角度后即到准停位置停止。 相似文献