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 ...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.展开更多
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 smoo...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.展开更多
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 num...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.展开更多
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 too...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%.展开更多
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...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.展开更多
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...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.展开更多
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 ...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.展开更多
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 th...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.展开更多
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 d...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.展开更多
By analyzing the role of public art in the construction and development of urban landscape, the concept of public art and its regional meaning are analyzed, the relation between public art and city sculpture is explai...By analyzing the role of public art in the construction and development of urban landscape, the concept of public art and its regional meaning are analyzed, the relation between public art and city sculpture is explained, it is pointed out that city sculpture could enhance the landscape of urban space and enrich public art. The functions of city sculpture are expounded in details, including guiding spatial communication, creating the sociality of humanistic environment, and communicating space with human. With the design of city sculpture at the entrance of Xiasi County in Southeast part of Guizhou Province for example, its location and status are analyzed, highlighting its special location advantages as well as the historical business climate, the sculpture integrates the ancient corn which represents commercial culture with butterfly which embodies the totem of Miao nationalities in Southeast Guizhou Province, therefore brings both the visual impact and culture features. Here the significance of regional city sculpture is summarized, it is emphasized that the city sculpture is the material carrier of city culture, the cultural source of original design elements and the concrete manifestation of regional spirit.展开更多
The algorithm is divided into two steps. The first step pre-locates the blank by aligning its centre of gravity and approximate normal vector with those of destination surfaces, with largest overlap of projections...The algorithm is divided into two steps. The first step pre-locates the blank by aligning its centre of gravity and approximate normal vector with those of destination surfaces, with largest overlap of projections of two objects on a plane perpendicular to the normal vector. The second step is optimizing an objective function by means of gradient-simulated annealing algorithm to get the best matching of a set of distributed points on the blank and destination surfaces. An example for machining hydroelectric turbine blades is given to verify the effectiveness of algorithm.展开更多
The water-conducting network of capillaries in vascular plants has evolved over hundreds of millions of years in order to be able to cope with bubble clogging,a problem which also affects modern microfluidic devices.D...The water-conducting network of capillaries in vascular plants has evolved over hundreds of millions of years in order to be able to cope with bubble clogging,a problem which also affects modern microfluidic devices.Decades of anatomical studies have revealed that plants growing in habitats in which the formation of bubbles,or emboli,is likely to be a frequent occurrence often have various forms of geometrical sculpturing on the internal surfaces of the xylem conduits.The possible function of such wall sculpturing has long been the subject of speculation.We have investigated the hypothesis that wall sculpturing is a functional adaptation designed to increase the wettability of the walls of xylem conduits,an effect which could be described as the inverse of the well-known lotus-effect.Our results show that wall sculpturing does enhance wettability.Importantly,theoretical calculations reveal that the geometric parameters of various types of wall sculpturing are such that the resulting surfaces are sufficiently rough to enhance wettability,but not significantly rougher.The results provide an appealing answer to the long-standing debate on the function of wall sculpturing in xylem conduits,and may provide biomimetic clues for new approaches to the removal of bubbles in microfluidic channels.展开更多
Bitmap (BMP) is a widely used format in image processing. With the combination of the digital image processing and computer numerically controlled (NC) techniques, we developed a bitmap-based NC single-step and mu...Bitmap (BMP) is a widely used format in image processing. With the combination of the digital image processing and computer numerically controlled (NC) techniques, we developed a bitmap-based NC single-step and multi-dot method. An example was provided to illustrate the application and principle of this bitmap-based method in our newly innovated sandblasting glass NC sculpture system.展开更多
Public art may promote the image and inner culture of the city, build and accumulate the gentle pulse of history and the cultural atmosphere, make public environment serve the people better, meet modern demand more to...Public art may promote the image and inner culture of the city, build and accumulate the gentle pulse of history and the cultural atmosphere, make public environment serve the people better, meet modern demand more to whom spirit enjoy. How are the whole development, cultural inside information, living standard of a city, can be embodied through the state of development of observing its public art at first, public art and development of the city complement each other.展开更多
Campus is a direct carrier for higher education and culture communication. Good landscape sculpture can produce great cohesion and impetus, and it can play an important role in campus landscape construction and cultur...Campus is a direct carrier for higher education and culture communication. Good landscape sculpture can produce great cohesion and impetus, and it can play an important role in campus landscape construction and cultural communication. Based on the premise of constructing a high-level experience campus culture, this paper analyzes and studies the landscape sculptures of three polytechnic universities in Chengdu from the perspective of perceptual engineering, and analyzes the historical inheritance and school-running characteristics of the three universities, to compare the campus spirit conveyed by the sculptures and the perceptual cognition felt by the teachers and students. The differences between the existing campus landscape sculptures and the campus culture construction goal are obtained, and the corresponding campus landscape sculpture promotion strategy is proposed.展开更多
Human beings rely on natural instinct to feel the world from the beginning of life, the experience in the spatial place reveals the essential point contacting man and environment, also sublimates the relationship betw...Human beings rely on natural instinct to feel the world from the beginning of life, the experience in the spatial place reveals the essential point contacting man and environment, also sublimates the relationship between man and environment. To deepen the understanding of the experience in the spatial place, we shift the origin of environmental landscape design from "design environment" to "design experience". The essence of experience is to arouse perception, such as senses, emotions, spirits, thinking, action to participate, among which "form, space, quality" as the carrier of landscape sculpture's place spirit and experience co-form a complete spatial place imagery of landscape sculpture. Place experience makes people able to experience a more detailed and richer world, these construction activities bring innovation consciousness with inner vitality, and detail the means of man observing the world while seeking a pluralistic world.展开更多
At the end of the seventies,science,philosophy and arts became a succulent material for poets,especially for those belonging to experimental groups like Susan Howe.Debths(2017),probably Howe’s last book,is a museum f...At the end of the seventies,science,philosophy and arts became a succulent material for poets,especially for those belonging to experimental groups like Susan Howe.Debths(2017),probably Howe’s last book,is a museum for any reader as it is not just an ensemble of memoirs and related poems,but also a source of pictorial and literary information.It includes extracts from 19th and 20th century texts(fairy tales,essays,and other genres)by her favorite influential authors as well as her ekphrastic poems that evocate paintings and sculptures from the Isabella Gardner Museum where she once found the inspiration.Even music has a place in this book,as Howe tends to include sound effects,interferences and references to musical pieces in her poems to make them multidimensional works of art.Along the pages,Howe highlights the materiality of writing,as well as the relevance of the form,especially in“Tom Tit Tot”,where she shows her mastery of the collage technique.All these carefully chosen pieces have the mission of representing the eternal return,the relativity of time,and how death can also be a beginning.展开更多
Chicago Millennium Park is a place where "post-modern architecture" concentrates, Cloud Gate, Crown Fountain and Jay Pritzker Music Pavilion are three representative post-modern architectures in the park. Mi...Chicago Millennium Park is a place where "post-modern architecture" concentrates, Cloud Gate, Crown Fountain and Jay Pritzker Music Pavilion are three representative post-modern architectures in the park. Millennium Park is an urban public space of Chicago City, its design concepts such as resource sharing and adaptation to local conditions are worth learning.展开更多
文摘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.
基金supported by National Natural Science Foundation of China (Grant No. 50875012)National Hi-tech Research and Development Program of China (863 Program, Grant No. 2008AA04Z124)+1 种基金National Science and Technology Major Project of China (Grant No. 2009ZX04001-141)Joint Construction Project of Beijing Municipal Commission of Education of China
文摘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.
文摘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.
文摘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%.
文摘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.
文摘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.
文摘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.
基金Partially supported by a grant from NSFC (60821002)
文摘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.
文摘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.
文摘By analyzing the role of public art in the construction and development of urban landscape, the concept of public art and its regional meaning are analyzed, the relation between public art and city sculpture is explained, it is pointed out that city sculpture could enhance the landscape of urban space and enrich public art. The functions of city sculpture are expounded in details, including guiding spatial communication, creating the sociality of humanistic environment, and communicating space with human. With the design of city sculpture at the entrance of Xiasi County in Southeast part of Guizhou Province for example, its location and status are analyzed, highlighting its special location advantages as well as the historical business climate, the sculpture integrates the ancient corn which represents commercial culture with butterfly which embodies the totem of Miao nationalities in Southeast Guizhou Province, therefore brings both the visual impact and culture features. Here the significance of regional city sculpture is summarized, it is emphasized that the city sculpture is the material carrier of city culture, the cultural source of original design elements and the concrete manifestation of regional spirit.
文摘The algorithm is divided into two steps. The first step pre-locates the blank by aligning its centre of gravity and approximate normal vector with those of destination surfaces, with largest overlap of projections of two objects on a plane perpendicular to the normal vector. The second step is optimizing an objective function by means of gradient-simulated annealing algorithm to get the best matching of a set of distributed points on the blank and destination surfaces. An example for machining hydroelectric turbine blades is given to verify the effectiveness of algorithm.
文摘The water-conducting network of capillaries in vascular plants has evolved over hundreds of millions of years in order to be able to cope with bubble clogging,a problem which also affects modern microfluidic devices.Decades of anatomical studies have revealed that plants growing in habitats in which the formation of bubbles,or emboli,is likely to be a frequent occurrence often have various forms of geometrical sculpturing on the internal surfaces of the xylem conduits.The possible function of such wall sculpturing has long been the subject of speculation.We have investigated the hypothesis that wall sculpturing is a functional adaptation designed to increase the wettability of the walls of xylem conduits,an effect which could be described as the inverse of the well-known lotus-effect.Our results show that wall sculpturing does enhance wettability.Importantly,theoretical calculations reveal that the geometric parameters of various types of wall sculpturing are such that the resulting surfaces are sufficiently rough to enhance wettability,but not significantly rougher.The results provide an appealing answer to the long-standing debate on the function of wall sculpturing in xylem conduits,and may provide biomimetic clues for new approaches to the removal of bubbles in microfluidic channels.
基金the Scientific and Technological Research Project of Ningxia Autonomous Region(Grant No.2002-014-05)
文摘Bitmap (BMP) is a widely used format in image processing. With the combination of the digital image processing and computer numerically controlled (NC) techniques, we developed a bitmap-based NC single-step and multi-dot method. An example was provided to illustrate the application and principle of this bitmap-based method in our newly innovated sandblasting glass NC sculpture system.
文摘Public art may promote the image and inner culture of the city, build and accumulate the gentle pulse of history and the cultural atmosphere, make public environment serve the people better, meet modern demand more to whom spirit enjoy. How are the whole development, cultural inside information, living standard of a city, can be embodied through the state of development of observing its public art at first, public art and development of the city complement each other.
文摘Campus is a direct carrier for higher education and culture communication. Good landscape sculpture can produce great cohesion and impetus, and it can play an important role in campus landscape construction and cultural communication. Based on the premise of constructing a high-level experience campus culture, this paper analyzes and studies the landscape sculptures of three polytechnic universities in Chengdu from the perspective of perceptual engineering, and analyzes the historical inheritance and school-running characteristics of the three universities, to compare the campus spirit conveyed by the sculptures and the perceptual cognition felt by the teachers and students. The differences between the existing campus landscape sculptures and the campus culture construction goal are obtained, and the corresponding campus landscape sculpture promotion strategy is proposed.
文摘Human beings rely on natural instinct to feel the world from the beginning of life, the experience in the spatial place reveals the essential point contacting man and environment, also sublimates the relationship between man and environment. To deepen the understanding of the experience in the spatial place, we shift the origin of environmental landscape design from "design environment" to "design experience". The essence of experience is to arouse perception, such as senses, emotions, spirits, thinking, action to participate, among which "form, space, quality" as the carrier of landscape sculpture's place spirit and experience co-form a complete spatial place imagery of landscape sculpture. Place experience makes people able to experience a more detailed and richer world, these construction activities bring innovation consciousness with inner vitality, and detail the means of man observing the world while seeking a pluralistic world.
文摘At the end of the seventies,science,philosophy and arts became a succulent material for poets,especially for those belonging to experimental groups like Susan Howe.Debths(2017),probably Howe’s last book,is a museum for any reader as it is not just an ensemble of memoirs and related poems,but also a source of pictorial and literary information.It includes extracts from 19th and 20th century texts(fairy tales,essays,and other genres)by her favorite influential authors as well as her ekphrastic poems that evocate paintings and sculptures from the Isabella Gardner Museum where she once found the inspiration.Even music has a place in this book,as Howe tends to include sound effects,interferences and references to musical pieces in her poems to make them multidimensional works of art.Along the pages,Howe highlights the materiality of writing,as well as the relevance of the form,especially in“Tom Tit Tot”,where she shows her mastery of the collage technique.All these carefully chosen pieces have the mission of representing the eternal return,the relativity of time,and how death can also be a beginning.
文摘Chicago Millennium Park is a place where "post-modern architecture" concentrates, Cloud Gate, Crown Fountain and Jay Pritzker Music Pavilion are three representative post-modern architectures in the park. Millennium Park is an urban public space of Chicago City, its design concepts such as resource sharing and adaptation to local conditions are worth learning.