The ball-screw feed drive has varying high-order dynamic characteristics due to flexibilities of the slender screw spindle and joints between components, and an obvious feature of non-collocated control when a direct ...The ball-screw feed drive has varying high-order dynamic characteristics due to flexibilities of the slender screw spindle and joints between components, and an obvious feature of non-collocated control when a direct position measurement using a linear＇scale is employed. The dynamic characteristics and non- collocated situation have long been the source of difficulties in motion and vibration control, and deterio- rate the achieved accuracy of the axis motion. In this study, a dynamic model using a frequency-based sub- structure approach is established, considering the flexibilities and their variation. The position-dependent variation of the dynamic characteristics is then fully investigated. A corresponding control strategy, which is composed of a modal characteristic modifier （MCM） and an intelligent adaptive tuning algorithm （ATA）, is then developed. The MCM utilizes a combination of peak filters and notch filters, thereby shaping the plant dynamics into a virtual collocated system and avoiding control spillover. An ATA using an artificial neural network （ANN） as a smooth parameter interpolator updates the parameters of the filters in real time in order to cope with the feed drive＇s dynamic variation. Numerical verification of the effectiveness and robustness of the orooosed strategy is shown for a real feed drive.展开更多
Since computer system functions are becoming increasingly complex, the user has to spend much more time on the process of seeking information, instead of utilizing the required infor- mation. Information intelligent p...Since computer system functions are becoming increasingly complex, the user has to spend much more time on the process of seeking information, instead of utilizing the required infor- mation. Information intelligent push technology could replace the traditional method to speed up the information retrieval process. The fuzzy cognitive map has strong knowledge representation ability and reasoning capability. Information intelligent push with the basis on fuzzy cognitive map could ab- stract the computer user＇ s operations to a fuzzy cognitive map, and infer the user＇ s operating inten- tions. The reasoning results will be translated into operational events, and drive the computer system to push appropriate information to the user.展开更多
The development of technologies such as big data and cyber-physical systems （CPSs） has increased the demand for product design. Product digital design involves completing the product design process using advanced di...The development of technologies such as big data and cyber-physical systems （CPSs） has increased the demand for product design. Product digital design involves completing the product design process using advanced digital technologies such as geometry modeling, kinematic and dynamic simulation, multi- disciplinary coupling, virtual assembly, virtual reality （VR）, multi-objective optimization （MOO）, and human-computer interaction. The key technologies of intelligent design for customized products include： a description and analysis of customer requirements （CRs）, product family design （PFD） for the customer base, configuration and modular design for customized products, variant design for customized products, and a knowledge push for product intelligent design. The development trends in intelligent design for customized products include big-data-driven intelligent design technology for customized products and customized design tools and applications. The proposed method is verified by the design of precision computer numerical control （CNC） machine tools.展开更多
With the increasing importance of cloud services worldwide, the cloud infrastructure and platform management has become critical for cloud service providers. In this paper, a novel architecture of intelligent server m...With the increasing importance of cloud services worldwide, the cloud infrastructure and platform management has become critical for cloud service providers. In this paper, a novel architecture of intelligent server management framework is proposed. In this framework, the communication layer is based on the Extensible Messaging and Presence Protocol (XMPP), which was developed for instant messaging and has been proven to be highly mature and suitable for mobile and large scalable deployment due to its extensibility and efficiency. The proposed architecture can simplify server management and increase flexibility and scalability when managing hundreds of thousands of servers in the cloud era.展开更多
基金This work was supported by the key project of the National Natural Science Foundation of China （51235009）.
文摘The ball-screw feed drive has varying high-order dynamic characteristics due to flexibilities of the slender screw spindle and joints between components, and an obvious feature of non-collocated control when a direct position measurement using a linear＇scale is employed. The dynamic characteristics and non- collocated situation have long been the source of difficulties in motion and vibration control, and deterio- rate the achieved accuracy of the axis motion. In this study, a dynamic model using a frequency-based sub- structure approach is established, considering the flexibilities and their variation. The position-dependent variation of the dynamic characteristics is then fully investigated. A corresponding control strategy, which is composed of a modal characteristic modifier （MCM） and an intelligent adaptive tuning algorithm （ATA）, is then developed. The MCM utilizes a combination of peak filters and notch filters, thereby shaping the plant dynamics into a virtual collocated system and avoiding control spillover. An ATA using an artificial neural network （ANN） as a smooth parameter interpolator updates the parameters of the filters in real time in order to cope with the feed drive＇s dynamic variation. Numerical verification of the effectiveness and robustness of the orooosed strategy is shown for a real feed drive.
基金Supported by the National Natural Science Foundation of China(61304254)
文摘Since computer system functions are becoming increasingly complex, the user has to spend much more time on the process of seeking information, instead of utilizing the required infor- mation. Information intelligent push technology could replace the traditional method to speed up the information retrieval process. The fuzzy cognitive map has strong knowledge representation ability and reasoning capability. Information intelligent push with the basis on fuzzy cognitive map could ab- stract the computer user＇ s operations to a fuzzy cognitive map, and infer the user＇ s operating inten- tions. The reasoning results will be translated into operational events, and drive the computer system to push appropriate information to the user.
基金The work presented in this article is funded by the National Natural Science Foundation of China （51375012 and 51675478）, the Science and Technology Plan Project of Zhejiang Province （2017C31002）, and the Fundamental Research Funds for the Central Universities （2017FZA4003）.
文摘The development of technologies such as big data and cyber-physical systems （CPSs） has increased the demand for product design. Product digital design involves completing the product design process using advanced digital technologies such as geometry modeling, kinematic and dynamic simulation, multi- disciplinary coupling, virtual assembly, virtual reality （VR）, multi-objective optimization （MOO）, and human-computer interaction. The key technologies of intelligent design for customized products include： a description and analysis of customer requirements （CRs）, product family design （PFD） for the customer base, configuration and modular design for customized products, variant design for customized products, and a knowledge push for product intelligent design. The development trends in intelligent design for customized products include big-data-driven intelligent design technology for customized products and customized design tools and applications. The proposed method is verified by the design of precision computer numerical control （CNC） machine tools.
文摘With the increasing importance of cloud services worldwide, the cloud infrastructure and platform management has become critical for cloud service providers. In this paper, a novel architecture of intelligent server management framework is proposed. In this framework, the communication layer is based on the Extensible Messaging and Presence Protocol (XMPP), which was developed for instant messaging and has been proven to be highly mature and suitable for mobile and large scalable deployment due to its extensibility and efficiency. The proposed architecture can simplify server management and increase flexibility and scalability when managing hundreds of thousands of servers in the cloud era.
