Direct interpolation algorithm for pen-cutting of sculptured surfaces

A direct interpolation algorithm for spatial curves on a surface is proposed for pen-cutting of sculptured surfaces. The algorithm can carry out the direct interpolation for projective curves lying on the sculptured surface. It is based on the geometric and kinetic relationships between drive curves and cutter-contact （C-C） curves. It evaluates the parameter of drive curves corresponding to interpolation points by the Taylor formula. Then it gains coordinates of interpolation points indirectly by inverse calculation. Finally, it generates the motion commands for machine tool controller. This method extends the locus-controlled function in the computer numerical control （CNC） system effectively and improves the efficiency for the numerical control （NC） machining of sculptured surfaces. The simulation shows that the proposed algorithm is feasible and practical. This algorithm can also be applied to the machining of the whole surface.

A NEW ALGORITHM BASED ON TRIANGULATION FOR 5 AXIS MACHINING OF SCULPTURED SURFACES

NC machining path of sculptured surfaces in CAD/CAM system plays an important role on manufacture. This paper describes a new algorithm for 5 axis machining of sculptured surfaces and the algorithm is interference free. The approach includes: (1) the tesselation of the parametric surfaces into triangles; (2) building topological relations among triangles;(3) 5 axis tool path generation; (4) interference detection and tool position correction.

Tool Positioning Algorithm Based on Smooth Tool Paths for 5-axis Machining of Sculptured Surfaces

The current research of the 5-axis tool positioning algorithm mainly focuses on searching the local optimal tool position without gouging and interference at a cutter contact（CC） point,while not considering the smoothness and continuity of a whole tool path.When the surface curvature varies significantly,a local abrupt change of tool paths will happen.The abrupt change has a great influence on surface machining quality.In order to keep generated tool paths smooth and continuous,a five-axis tool positioning algorithm based on smooth tool paths is presented.Firstly,the inclination angle,the tilt angle and offset distance of the tool at a CC point are used as design variables,and the machining strip width is used as an objective function,an optimization model of a local tool positioning algorithm is thus established.Then,a vector equation of tool path is derived by using the above optimization model.By analyzing the equation,the main factors affecting the tool path quality are obtained.Finally,a new tool position optimization model is established,and the detailed process of tool position optimization is also given.An experiment is conducted to machine an aircraft turbine blade by using the proposed algorithm on a 5-axis blade grinding machine,and the machined blade surface is measured with a coordinate measuring machine（CMM）.Experimental and measured results show that the proposed algorithm can ensure tool paths are smooth and continuous,improve the tool path quality,avoid the local abrupt change of tool paths,and enhance machining quality and machining efficiency of sculptured surfaces.

NON-CONTACT MEASUREMENT OF SCULPTURED SURFACE OF ROTATION

A method for measuring the sculptured surface of rotation by using coordinatemeasuring machine (CMM) and rotary table is proposed. The measurement is realized during thecontinuous rotation of the workpiece mounted on the rotary table while the probe moves along thegeneratrix of the surface step by step. This method possesses lots of advantages such as simplicityof probe motion, high reliability and efficiency. Some key techniques including calibration of theeffective radius of the probing system, determination of the position of axis of rotation,auto-centering of the workpiece, data processing algorithm, are discussed. Approaches fordetermining the coordinates on measured surface, establishing workpiece coordinate system andsurface fitting are presented in detail. The method can be used with contact or non-contact probes.Some fragile ceramic and plaster parts are measured by using the system consisting of a CMM, rotarytable, motorized head and non-contact laser triangulation probe. The measuring uncertainty is about0.02 mm which meets the general requirement in most cases.

NC Rough Machining of Sculptured Surface Based on Measured Data

A new method for generating tool paths for rough machining of sculpturedsurface is presented in this paper. The sculptured surface is approximated by a regular mesh ofquadrangular facets. A set of equidistant horizontal planes are assigned to intersect the blank ofmachined part and surface model , resulting in a series of contours, which demarcate the feasiblecutting regions of each layer of material removal. The desired cutter path is computed through NCprogramming and any gouging between the cutter and the part being machined is detected and correctedautomatically. The proposed algorithm successfully solves the problem of layered milling forsculptured surface with nested islands.

Robust Boolean Operation for Sculptured Models

To enhance the ability of current modeling system, an uniformed representation is designed to represent wire frame, solid, surface models. We present an algorithm for Boolean operation between the models under this representation. Accuracy, efficiency and robustness are the main consideration. The geometric information is represented with trimmed parametric patches and trimmed parametric splines. The topological information is represented with an extended half edge data structure. In the process of intersection calculation, hierarchy intersection method is applied for unified classification. Tracing the intersection curve to overcome degenerate cases that occur frequently in practice. The algorithm has been implemented as the modeling kernel of a feature based modeling system named GS CAD98, which was developed on Windows/NT platform.

Adaptive compensation of sculptured surface machining errors by open architecture manufacturing system

Presents the adaptive compensation of sculptured surface machining errors by using the open architecture intelligent manufacturing system to ensure real time high precision machining of sculptured surface, and the tool deflection model constructed for prediction of machining errors to be compensated and analysis of the effect of tool deflection on machining errors, and concludes from experimental results that the open architecture intelligent manufacturing system can effectively improve the machining precision and reduce the machining errors by 30%.

Frame Design and Reality of Numerical Model for Sculptured Part Machining

The importance of the numerical model for sculptured part machining based on virtual environment is introduced. Meanwhile, the general frame of the numerical model is proposed, and the techniques of developing the numerical model are discussed in detail.

Band-Reject Filters for Bragg Mirror Using Perturbed Chiral Sculptured Thin Films

We have theoretically simulated the optical properties of perturbed chiral STF （sculptured thin film） with and without defect. It was revealed that such STFs could act as band-reject filters with tunable Bragg regime of free space wavelengths and different bandwidth through changing the vapor incident angle during glancing angle deposition process. These Bragg filters are narrowing due to the change of vapor incident angle for circularly polarized light. Interestingly, as the vapor incident angle increased, the band-rejected filter exhibited to decrease the bandwidth and shifted in the Bragg regime, indicating that such STF nanostructures have high potential for behaving as unique polarization insensitive Bragg mirror.

A Tool Path Generation Strategy for Sculptured Surfaces Machining

This paper presents a strategy to generate interference-free tool paths for machining sculptured surfaces. The strategy proposed here is first to determine the tool path topology. The values of the step length and the path interval are then calculated based on the machining tolerance requirements. After detecting and eliminating the tool interference, the interference-free tool path is generated. The effectiveness of the developed algorithm is demonstrated through simulation and actual cutting tests.

Dual Drive Curve Tool Path Planning Method for 5-axis NC Machining of Sculptured Surfaces

The problem of finished surface being not first-order continuous commonly exists in machining sculptured surfaces with a torus cutter and some other types of cutters. To solve this problem, a dual drive curve tool path planning method is proposed in this article. First, the maximum machining strip width of a whole tool path can be obtained through optimizing each tool position with multi-point machining （MPM） method. Second, two drive curves are then determined according to the obtained maximum machining strip width. Finally, the tool is positioned once more along the dual drive curve under the condition of tool path smoothness. A computer simulation and cutting experiments are carried out to testify the performance of the new method. The machined surface is measured with a coordinate measuring machine （CMM） to examine the machining quality. The results obtained show that this method can effectively eliminate sharp scallops between adjacent tool paths, keep tool paths smooth, and improve the surface machining quality as well as machining efficiency.

Hypatia of Alexandria:A Fiercely Intelligent Woman

The novel Hypatia:Or New Foes With an Old Face by Charles Kingsley,published in 1853,provided valuable insight into Hypatia’s achievements and the unfortunate circumstances surrounding her untimely demise.Kingsley’s novel portrayed a fiercely intelligent woman,Hypatia,who sparked the interest of many artists,particularly sculptors.They were eager to capture in their statues the personification of this remarkable ancient mathematician,philosopher,and scientist of ancient Egypt,Hypatia of Alexandria(355-415).This essay has two parts.The first provides a brief overview of Hypatia’s life and accomplishments.The second part focuses on four sculptures from the 19th century created by different artists:Hypatia(1873-1876)by the American Howard Roberts,Hypatia(1874)by the Italian Odoardo Tabacchi,Hypatia(1890)by Francis John Williamson,and Hypatia(1894)by Richard Claude Belt.The two latter works are by British sculptors.

Formal Integration of Decorative Elements in the Creation of Figurative Sculpture

Figurative sculpture and decorative elements belong to the same category of art;the development of sculpture art requires innovation and constant exploration of new development paths,while many characteristics of decorative elements can give the creation of sculpture works a variety of inspiration.This paper explores the significance of figurative sculpture and decorative elements,examining their intrinsic connections and historical practices.The study aims to uncover the potential of figurative sculpture in the creation of decorative elements,highlighting how the integration of these forms can contribute to the development of art and the creation of meaningful figurative sculptures.

Application of Chinese Ethnic Minority Themes in Contemporary Figurative Sculpture Creation

In the field of contemporary sculpture creation,the rich culture and historical depth of Chinese ethnic minorities have attracted the widespread attention of artists.These creations not only emphasize external features such as ethnic costumes,totems,or life scenes but also touch deep spiritual contents including historical stories,religious beliefs,and living habits of ethnic minorities.This paper discusses the integration process of Chinese ethnic minority themes in figurative sculpture creation and the inheritance of the profound spirit of ethnic groups in this process.At the same time,this paper also places the diversified expression and innovative practice of these themes in sculpture art in the context of the new era for investigation and explores the far-reaching influence of its development on promoting cultural inheritance and artistic innovation.

The Birth and Custody of Infant Bacchus

This article discusses the visual aspects of the birth of Dionysus/Bacchus,the God of Agriculture,Revelry,and Wine,in classical art.It examines the historical and iconographic aspects of the infant Dionysus’s custody by two deities,Silenus and Mercury,in ancient classical art,particularly in Roman frescoes and sculptural reliefs,and its echoes in Italian Renaissance engravings.

Realization Methodology of a 5-axis Spline Interpolator in an Open CNC System

By making use of the advantages of non-uniform rational B-spline （NURBS） curves to represent spatial curves, an instruction format with double NURBS curves suitable for 5-axis coordinated real-time interpolation is presented to replace the current 5-axis coordinated linear interpolation method defective in low-speed, low-accuracy and enormous numerical control （NC） files in sculptured surface machining. A generation procedure of the NC files with the presented format is introduced and the method to realize the interpolation in an open computer numerical control （CNC） system is developed by ourselves. These illustrated the feasibility of the proposed method and its capability of avoiding all the shortages of 5-axis linear interpolation method.

A new iso-scallop height tool path planning method in three-dimensional space

This paper presents a new approach for designing the tool paths in the machining of sculptured surfaces for computer nu- merical controlled end milling. In the proposed method, the tool paths are determined so that the scallop height formed by two adja- cent machining paths is maintained constant across the machined surface. Unlike previous work on iso-scallop height milling, the present work considers the true 3D configuration of the milling procedure and can be used to generate better results, which is shown by examoles.

Landscape Architecture and Sculpture Made A New Structure of A New Era

Landscape design and sculpture art have gradually integrated into each other, as sculptures are no longer limited in art galleries but adapted to various environments, and gardens are trying to make earth into a great work of art by using sculptures. The interpenetrating and tolerance of sculpture and garden has changed the appearance of environmental landscape, and led to a new era of art and design.

Wideband Antireflection Film Fabricated by Glancing Angle Deposition

Graded-index ZrO2 films has been fabricated on K9 glass by glancing angle deposition. Because the index mismatch at the interface has been reduced, the film results in wideband high-transmission antireflection. From 400nm to 1200nm, the film reflection is lower than 0.8% and the lowest value is 0.2% at 432nm.

A Generic Kinematic Model for Three Main Types of Five-axis Machine Tools

Material removal is one of the most used processes in manufacturing. Five-axis CNC machines are believed to be the best tools in sculptured surface machining. In this study, a generic and unified kinematic model was developed as a viable alternative to the particular solutions that are only applicable to individual machine configurations. This versatile model is then used to verify the feasibility of the two rotational joints within the kinematic chain of three main types of a five-axis machine-tool. This versatile model is very useful applied to the design of five-axis machine tools.