资源类型

期刊论文 821

年份

2024 1

2023 48

2022 62

2021 45

2020 47

2019 53

2018 38

2017 49

2016 35

2015 42

2014 31

2013 35

2012 30

2011 35

2010 43

2009 45

2008 34

2007 37

2006 24

2005 12

展开 ︾

关键词

设计 19

三峡工程 11

优化设计 9

增材制造 8

多目标优化 7

机器学习 5

材料设计 5

创新设计 4

施工 4

3D打印 3

协同设计 3

DSM(设计结构矩阵) 2

D区 2

TRIZ 2

三塔悬索桥 2

不确定性 2

人员疏散 2

仿真 2

创新 2

展开 ︾

检索范围:

排序: 展示方式:

Development of a redundant anthropomorphic hydraulically actuated manipulator with a roll–pitch–yaw spherical

《机械工程前沿(英文)》 2021年 第16卷 第4期   页码 698-710 doi: 10.1007/s11465-021-0646-2

摘要: The demand for redundant hydraulic manipulators that can implement complex heavy-duty tasks in unstructured areas is increasing; however, current manipulator layouts that remarkably differ from human arms make intuitive kinematic operation challenging to achieve. This study proposes a seven-degree-of-freedom (7-DOF) redundant anthropomorphic hydraulically actuated manipulator with a novel roll–pitch–yaw spherical wrist. A hybrid series–parallel mechanism is presented to achieve the spherical wrist design, which consists of two parallel linear hydraulic cylinders to drive the yaw/pitch 2-DOF wrist plate connected serially to the roll structure. Designed as a 1R PRRR-1S PU mechanism (“R”, “P”, “S”, and “U” denote revolute, prismatic, spherical, and universal joints, respectively; the underlined letter indicates the active joint), the 2-DOF parallel structure is partially decoupled to obtain simple forward/inverse kinematic solutions in which a closed-loop subchain “R PRR” is included. The 7-DOF manipulator is then designed, and its third joint axis goes through the spherical center to obtain closed-form inverse kinematic computation. The analytical inverse kinematic solution is drawn by constructing self-motion manifolds. Finally, a physical prototype is developed, and the kinematic analysis is validated via numerical simulation and test results.

关键词: hydraulic manipulator     inverse kinematic     redundant design     spherical wrist    

Optimal design of a linkage–cam mechanism-based redundantly actuated parallel manipulator

《机械工程前沿(英文)》 2021年 第16卷 第3期   页码 451-467 doi: 10.1007/s11465-021-0634-6

摘要: A redundantly actuated parallel manipulator (RAPM) with mixed translational and rotational degrees of freedom (DOFs) is challenged for its dimensionally homogeneous Jacobian modeling and optimal design of architecture. In this paper, a means to achieve redundant actuation by adding kinematic constraints is introduced, which reduces the DOFs of the end-effector (EE). A generic dimensionally homogeneous Jacobian is developed for this type of RAPMs, which maps the generalized velocities of three points on the EE to the joint velocities. A new optimization algorithm derived from this dimensionally homogeneous Jacobian is proposed for the optimal design of this type of RAPMs. As an example, this paper presents a spatial RAPM involving linkages and cam mechanisms. This RAPM has 4 DOFs and 6 translational actuations. The linkage lengths and the position of the universal joints of the RAPM are optimized based on the dimensionally homogeneous Jacobian.

关键词: redundant actuation     parallel manipulator     linkage–cam mechanism     Jacobian     optimal design    

Design and analysis of a class of redundant collaborative manipulators with 2-dimension large rotational

Xiaodong JIN, Yuefa FANG, Dan ZHANG, Xueling LUO

《机械工程前沿(英文)》 2020年 第15卷 第1期   页码 66-80 doi: 10.1007/s11465-019-0570-x

摘要: The parallel spindle heads with high rotational capability are demanded in the area of multi-axis machine tools and 3D printers. This paper focuses on designing a class of 2R1T (R: Rotation; T: Translation) parallel spindle heads and the corresponding collaborative 5-axis manipulators with 2-dimension (2D) large rotational angles. In order to construct 2D rotational degrees of freedom (DOF), a platform with 2-dimension revolute joints is proposed first. Based on the constraint screw theory, the feasible limbs that can be connected in the platform are synthesized. In order to provide constant rotational axis for the platform, a class of redundant limbs are designed. A class of redundant 2R1T parallel spindle heads is obtained by connecting the redundant limbs with the platform and the redundant characteristics are verified by the modified Grübler-Kutzbach criterion. The corresponding 5-axis collaborative manipulators are presented by constructing a 2-DOF series translational bottom moving platform. The inverse kinematics and the orientation workspace as well as the decoupling characteristics of this type of 2R1T parallel spindle heads are analyzed. The results show that these manipulators have large 2D rotational angles than the traditional A3/Z3 heads and can be potentially used in the application of multi-axis machine tools and the 3D printers.

关键词: parallel mechanism     redundant mechanism     large rotational angles     machine tools     2R1T spindle head     collaborative manipulator    

自适应自动程序设计及其在自动售货机中的应用

余世明,丁国正,刘立峰

《中国工程科学》 2007年 第9卷 第11期   页码 147-150

摘要:

对程序故障的处理,通常可以使用返回值或异常来报告。但当状态模型中的程序出现故障后,使程 序仍能回到出现故障处的状态或做进一步的处理,这是返回值或异常做不到的。针对自动处理的实现,提出 了采用组合编码和状态冗余设计相结合的自动程序设计思想,给出了它的一个结构模型和算法。模型通过 减少程序的状态切换故障(预防)和增加系统的故障恢复能力(治疗)来实现这个目标。最后,将这个设计模 型部分成功地应用到自动售货机上,实际运行效果良好。

关键词: 自适应     状态冗余设计     自动程序设计     故障恢复     自动售货机    

Ahybrid biogeography-based optimization method for the inverse kinematics problem of an 8-DOF redundant

Zi-wu REN,Zhen-hua WANG,Li-ning SUN

《信息与电子工程前沿(英文)》 2015年 第16卷 第7期   页码 607-616 doi: 10.1631/FITEE.14a0335

摘要: The redundant humanoid manipulator has characteristics of multiple degrees of freedom and complex joint structure, and it is not easy to obtain its inverse kinematics solution. The inverse kinematics problem of a humanoid manipulator can be formulated as an equivalent minimization problem, and thus it can be solved using some numerical optimization methods. Biogeography-based optimization (BBO) is a new biogeography inspired optimization algorithm, and it can be adopted to solve the inverse kinematics problem of a humanoid manipulator. The standard BBO algorithm that uses traditional migration and mutation operators suffers from slow convergence and prematurity. A hybrid biogeography-based optimization (HBBO) algorithm, which is based on BBO and differential evolution (DE), is presented. In this hybrid algorithm, new habitats in the ecosystem are produced through a hybrid migration operator, that is, the BBO migration strategy and DE/best/1/bin differential strategy, to alleviate slow convergence at the later evolution stage of the algorithm. In addition, a Gaussian mutation operator is adopted to enhance the exploration ability and improve the diversity of the population. Based on these, an 8-DOF (degree of freedom) redundant humanoid manipulator is employed as an example. The end-effector error (position and orientation) and the ‘away limitation level’ value of the 8-DOF humanoid manipulator constitute the fitness function of HBBO. The proposed HBBO algorithm has been used to solve the inverse kinematics problem of the 8-DOF redundant humanoid manipulator. Numerical simulation results demonstrate the effectiveness of this method.

关键词: Inverse kinematics problem     8-DOF humanoid manipulator     Biogeography-based optimization (BBO)     Differential evolution (DE)    

一种用于文本分类的去冗余特征选择新方法 None

You-wei WANG, Li-zhou FENG

《信息与电子工程前沿(英文)》 2018年 第19卷 第2期   页码 221-234 doi: 10.1631/FITEE.1601761

摘要: 特征选择是文本分类领域一种重要降维方法。针对传统特征选择方法所选特征集常包含冗余信息的问题,提出一种能够有效去除冗余信息的特征选择新方法。首先,为衡量两个词之间的关系,引入基于词频的相关性和相对冗余词集的概念;接着,选择一种最优特征选择方法并用其获得一个临时特征子集;最后,为提高算法执行效率,结合预设阈值去除临时特征子集中的冗余特征,并将结果存储在链表结构中。实验以支持向量机和朴素贝叶斯作为分类器,并以WebKB、20-Newsgroups和Reuters-21578作为测试数据集。实验结果表明,该方法分类精度高于传统特征选择方法;相对于基于互信息的方法而言,该方法能够在保证分类精度的同时,有效提高运行效率。

关键词: 特征选择;降维;文本分类;冗余特征;支持向量机;朴素贝叶斯;互信息    

Optimal redundant placement of PMUs in Indian power grid — northern, eastern and north-eastern regions

Pathirikkat GOPAKUMAR, G. Surya CHANDRA, M. Jaya Bharata REDDY, Dusmata Kumar MOHANTA

《能源前沿(英文)》 2013年 第7卷 第4期   页码 413-428 doi: 10.1007/s11708-013-0274-6

摘要: Effective utilization of renewable energy sources and efficient management of electric energy are essential for any developing countries like India. This can be envisioned through the implementation of concepts of smart grid (SG). One of the key requisites for SG implementation is that the grid should be completely observable. Renovation of conventional Indian power grid to a SG necessitates incorporation of the phasor measurement units (PMUs) in the present power grid measurement and monitoring system. Since the cost of PMU is high and any bus containing a PMU makes the neighboring connected buses observable, optimal placement of PMUs is very important for complete observability of the grid. This paper proposes optimal redundant geographical locations in the northern, eastern and north-eastern regions of Indian power grid for PMU placement. The PMUs installed in these geographical locations will make the grid completely observable and maintain the observability under the conditions of failure of some PMUs or branch outages. Integer linear programming has been used for finding the optimal PMU locations. The results proposed in this paper can be a stepping stone for revamping the Indian power grid to a SG ensuring complete observability during different contingency conditions.

关键词: phasor measurement unit (PMU)     smart grid (SG)     Indian power grid     northern region Indian power grid (NRIPG)     eastern region Indian power grid (ERIPG)     north-eastern region Indian power grid (NERIPG)     redundancy     integer linear programing (ILP)    

Precise semi-analytical inverse kinematic solution for 7-DOF offset manipulator with arm angle optimization

《机械工程前沿(英文)》 2021年 第16卷 第3期   页码 435-450 doi: 10.1007/s11465-021-0630-x

摘要: Seven-degree-of-freedom redundant manipulators with link offset have many advantages, including obvious geometric significance and suitability for configu-ration control. Their configuration is similar to that of the experimental module manipulator (EMM) in the Chinese Space Station Remote Manipulator System. However, finding the analytical solution of an EMM on the basis of arm angle parameterization is difficult. This study proposes a high-precision, semi-analytical inverse method for EMMs. Firstly, the analytical inverse kinematic solution is established based on joint angle parameterization. Secondly, the analytical inverse kinematic solution for a non-offset spherical–roll–spherical (SRS) redundant manipulator is derived based on arm angle parameterization. The approximate solution of the EMM is calculated in accordance with the relationship between the joint angles of the EMM and the SRS manipulator. Thirdly, the error is corrected using a numerical method through the analytical inverse solution based on joint angle parameterization. After selecting the stride and termination condition, the precise inverse solution is computed for the EMM based on arm angle parameterization. Lastly, case solutions confirm that this method has high precision, and the arm angle parameterization method is superior to the joint angle parameterization method in terms of parameter selection.

关键词: 7-DOF redundant manipulator     inverse kinematics     semi-analytical     arm angle     link offset    

A redundantly actuated PRPRP radial mechanism in the segment erector of a shield machine for synchronization control

Wanghui BU, Zhenyu LIU, Jianrong TAN, Jin CHENG

《机械工程前沿(英文)》 2011年 第6卷 第4期   页码 463-467 doi: 10.1007/s11465-011-0225-z

摘要:

The shield machine is a heavy construction machine for tunnel excavation, and the segment erector is an important subsystem of the shield machine. It is difficult to achieve precise control in the 6-DOF (degree of freedom) erector in the 2-DOF 5-bar radial mechanism. Hence, this paper proposes a redundantly actuated PRPRP radial mechanism for the segment erector. When the redundant actuator is unlocked, the radial mechanism is able to adjust its posture, which has two degrees of freedom. On the other hand, when the redundant actuator is locked or produces enough pre-tightening tensile force, the PRPRP mechanism can ensure the synchronization of the two driving hydraulic cylinders along the radial direction based on the mechanical structure, which has one degree of freedom. The redundant actuator also facilitates the equal application of two flexural torques at the hydraulic cylinders; thus, preventing the overload of a single cylinder.

关键词: redundant actuation     parallel mechanisms     five-bar mechanisms     segment erectors     shield machines    

自恢复容错系统的建模与分析

郭成昊,刘凤玉

《中国工程科学》 2007年 第9卷 第10期   页码 75-79

摘要:

容错系统不仅会产生硬件故障,由于连续长时间的运行,系统的性能也会逐渐下降或失效,即老化现象。综合考虑容错系统中的硬件故障和老化现象,提出了将传统的冗余技术和软件抗衰技术相结合的策略,并给出了该系统的非马尔可夫随机Petri网模型,随之对基于该模型的系统进行了定量分析。

关键词: 容错系统     软件抗衰     软件老化     冗余策略     非马尔可夫随机Petri网    

具有冗余结构的分布式数据库服务器及其负载平衡模型

田俊峰,刘玉玲,杜瑞忠

《中国工程科学》 2004年 第6卷 第6期   页码 35-42

摘要:

服务器冗余技术在解决传统分布式环境的可用性和性能瓶颈问题的同时给系统的管理带来了新的挑战。介绍了一种分布式数据库服务器的构成原理及工作模型,重点讨论了它的冗余关系、基于移动代理的负载平衡模型及其性能分析等。

关键词: 分布式数据库     冗余     负载平衡     移动代理     性能分析    

网络空间内生安全 Article

邬江兴

《工程(英文)》 2022年 第15卷 第8期   页码 179-185 doi: 10.1016/j.eng.2021.05.015

摘要:

基于未知漏洞后门等产生的不确定威胁是当前网络空间最为严峻和棘手的安全问题。本文分析了系统漏洞后门等“暗功能”存在的哲学与技术层面的原因,并作为系统“内生安全问题”存在的必然性依据,指出“内生安全问题”在理论和工程层面不可能完全彻底地消除,需要“开发或利用”系统架构自身的“内源性安全功能”,使目标对象能够通过“内生的安全体制机制”来有效规避或化解内生安全问题可能引发的安全风险。文中给出了网络空间内生安全的定义和期望的体制机制及其主要技术特征,介绍了基于动态异构冗余架构的内生安全体制机制及其内生安全特性,阐述了创新的基于DHR架构的编码信道理论内涵。

关键词: 网络空间内生安全问题     不确定威胁     网络空间内生安全     相对正确公理     动态异构冗余架构    

Reliability design method for steam turbine blades

SHI Jinyuan

《能源前沿(英文)》 2008年 第2卷 第4期   页码 363-368 doi: 10.1007/s11708-008-0073-7

摘要: Based on theories of probability and statistics, and taking static stresses, dynamic stresses, endurance strength, safety ratios, vibration frequencies and exciting force frequencies of blades as random variables, a reliability design method for steam turbine blades is presented. The purport and calculation method for blade reliability are expounded. The distribution parameters of random variables are determined after analysis and numerical calculation of test data. The fatigue strength and the vibration design reliability of turbine blades are determined with the aid of a probabilistic design method and by interference models for stress distribution and strength distribution. Some blade reliability design calculation formulas for a dynamic stress design method, a safety ratio design method for fatigue strength, and a vibration reliability design method for the first and second types of tuned blades and a packet of blades on a disk connected closely, are given together with some practical examples. With these methods, the design reliability of steam turbine blades can be guaranteed in the design stage. This research may provide some scientific basis for reliability design of steam turbine blades.

关键词: design reliability     force     probability     purport     reliability design    

Assembly design system based on engineering connection

Wensheng YIN

《机械工程前沿(英文)》 2016年 第11卷 第4期   页码 423-432 doi: 10.1007/s11465-016-0382-1

摘要:

An assembly design system is an important part of computer-aided design systems, which are important tools for realizing product concept design. The traditional assembly design system does not record the connection information of production on the engineering layer; consequently, the upstream design idea cannot be fully used in the downstream design. An assembly design model based on the relationship of engineering connection is presented. In this model, all nodes are divided into two categories: The component and the connection. Moreover, the product is constructed on the basis of the connection relationship of the components. The model is an And/Or graph and has the ability to record all assembly schemes. This model records only the connection information that has engineering application value in the product design. In addition, this model can significantly reduce the number of combinations, and is very favorable for the assembly sequence planning in the downstream. The system contains a connection knowledge system that can be mapped to the connection node, and the connection knowledge obtained in practice can be returned to the knowledge system. Finally, VC++6.0 is used to develop a prototype system called Connect-based Assembly Planning (CAP). The relationship between the CAP system and the commercial assembly design system is also established.

关键词: product design     assembly design     engineering connection     assembly sequence planning    

设计科学的争论和设计竞争力

谢友柏

《中国工程科学》 2014年 第16卷 第8期   页码 4-13

摘要:

本文回溯了19 世纪末以来西方关于设计科学的争论,探讨在前工业设计时期、工业设计时期和后工业设计时期中关于设计认知和理念的变化,特别是它们在整个工业设计时期中随同满足物质需求产品生产能力增长而发生的转变。事实表明,当产能不满足物质需求时,工业生产是以规模竞争优先;而当规模发展到极端而导致产能过剩并引发许多社会问题时,工业生产就转向创新竞争。竞争模式改变导致设计认知和理念的变化:从保证大规模物质生产、符合物质演变规律,即理性的系统化的设计,到满足人们对新的和美好生活的追求,并同时满足物质需求、精神需求和社会需求统一的由创意引领的设计。哪一个设计能使创新成功,取决于竞争,不仅仅是市场竞争,而且是在社会发展中的竞争。现在不是会不会设计的问题,而是设计有没有竞争力。中国正处在经济增长方式转变的关键时期,推动设计科学的研究,认识这些变化非常重要。本文提出了“竞争性设计”和“继承性设计”的概念,并将后工业设计时期称为竞争性设计时期。

关键词: 设计     工业设计     设计科学     知识     知识获取    

标题 作者 时间 类型 操作

Development of a redundant anthropomorphic hydraulically actuated manipulator with a roll–pitch–yaw spherical

期刊论文

Optimal design of a linkage–cam mechanism-based redundantly actuated parallel manipulator

期刊论文

Design and analysis of a class of redundant collaborative manipulators with 2-dimension large rotational

Xiaodong JIN, Yuefa FANG, Dan ZHANG, Xueling LUO

期刊论文

自适应自动程序设计及其在自动售货机中的应用

余世明,丁国正,刘立峰

期刊论文

Ahybrid biogeography-based optimization method for the inverse kinematics problem of an 8-DOF redundant

Zi-wu REN,Zhen-hua WANG,Li-ning SUN

期刊论文

一种用于文本分类的去冗余特征选择新方法

You-wei WANG, Li-zhou FENG

期刊论文

Optimal redundant placement of PMUs in Indian power grid — northern, eastern and north-eastern regions

Pathirikkat GOPAKUMAR, G. Surya CHANDRA, M. Jaya Bharata REDDY, Dusmata Kumar MOHANTA

期刊论文

Precise semi-analytical inverse kinematic solution for 7-DOF offset manipulator with arm angle optimization

期刊论文

A redundantly actuated PRPRP radial mechanism in the segment erector of a shield machine for synchronization control

Wanghui BU, Zhenyu LIU, Jianrong TAN, Jin CHENG

期刊论文

自恢复容错系统的建模与分析

郭成昊,刘凤玉

期刊论文

具有冗余结构的分布式数据库服务器及其负载平衡模型

田俊峰,刘玉玲,杜瑞忠

期刊论文

网络空间内生安全

邬江兴

期刊论文

Reliability design method for steam turbine blades

SHI Jinyuan

期刊论文

Assembly design system based on engineering connection

Wensheng YIN

期刊论文

设计科学的争论和设计竞争力

谢友柏

期刊论文