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混联机械系统方案设计特征状态空间理论与方法 被引量:12
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作者 张利萍 王德伦 《机械工程学报》 EI CAS CSCD 北大核心 2006年第12期26-35,共10页
提出混联机械系统运动方案设计与综合的运动功能特征状态空间理论模型。构建混联运动功能特征状态空间,转换设计空间对象到特征状态空间元素,分析特征状态空间构成要素的空间关联关系。进一步探讨空间及其元素性质,研究对偶矢量间运算... 提出混联机械系统运动方案设计与综合的运动功能特征状态空间理论模型。构建混联运动功能特征状态空间,转换设计空间对象到特征状态空间元素,分析特征状态空间构成要素的空间关联关系。进一步探讨空间及其元素性质,研究对偶矢量间运算规则和度量方式,形成抽象有序的封闭空间框架。总结特征状态空间与设计解空间相互映射的方案综合理论,实现运动功能分析的数学求解模式,得到特征状态空间理论对系统设计的运用指导过程。设计实例说明该方法的可行性和实用性。 展开更多
关键词 概念设计 混联系统 对偶矢量 特征状态空间
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一种自动化单元批量生产质量分析新方法 被引量:1
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作者 杜广宇 王德伦 +1 位作者 董惠敏 钱峰 《组合机床与自动化加工技术》 北大核心 2016年第2期153-156,共4页
以机械制造企业自动化单元的生产过程质量控制为研究对象,提出了一种自动化单元批量生产质量分析的新方法,对生产过程的中零件质量建立状态空间模型,提取质量特征矢量来描述某一阶段的加工状态。以质量状态变换方程刻画零件的加工过程,... 以机械制造企业自动化单元的生产过程质量控制为研究对象,提出了一种自动化单元批量生产质量分析的新方法,对生产过程的中零件质量建立状态空间模型,提取质量特征矢量来描述某一阶段的加工状态。以质量状态变换方程刻画零件的加工过程,通过状态变换方程的串联叠加实现对多工序生产系统的数学描述;通过数控生产线监控管理系统获取生产过程中零件质量相关信息,以这些数据为基础条件求解生产系统特征矩阵,并结合生产过程特征熵来评价生产过程,实现质量控制。实例分析说明该方法正确性和有效性,为自动化单元批量生产提供一种有效的生产过程评价和产品质量分析方法。 展开更多
关键词 特征状态空间 质量分析 生产评价 生产特征
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智能车辆弧线跟踪控制算法 被引量:6
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作者 王荣本 张荣辉 +2 位作者 游峰 储江伟 金立生 《吉林大学学报(工学版)》 EI CAS CSCD 北大核心 2006年第5期731-735,共5页
建立了车辆预瞄运动学模型,通过最优控制选取切换超平面,采用滑模变结构控制实现了智能车辆弧线跟踪中弧线曲率小变化时的导航控制。根据模糊控制快速跟踪弧线曲率大变化时的导航路径,结合车辆转向系统当前状态和最快动态响应能力建立... 建立了车辆预瞄运动学模型,通过最优控制选取切换超平面,采用滑模变结构控制实现了智能车辆弧线跟踪中弧线曲率小变化时的导航控制。根据模糊控制快速跟踪弧线曲率大变化时的导航路径,结合车辆转向系统当前状态和最快动态响应能力建立了智能车辆弧线跟踪时的变结构控制输出集。仿真分析和实验验证了该融合控制算法在智能车辆弧线跟踪过程中的平稳性和可靠性。 展开更多
关键词 自动控制技术 预瞄运动学 滑模变结构控制 模糊控制 状态特征空间 智能车辆
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五轴多工序加工检测夹具下的误差成本优化分析 被引量:2
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作者 丁杰雄 李菲 +2 位作者 吕强 杜丽 王伟 《计算机集成制造系统》 EI CSCD 北大核心 2018年第12期2941-2952,共12页
为平衡多工序制造系统中质量与成本的问题,提出一种在机检测夹具间接影响质量与成本的求解方式。在该求解方式中,分析了在机检测夹具变量误差的特点,采用状态空间法建立了误差传递模型;分析了在机检测夹具的成本,采用显著性检验的方法... 为平衡多工序制造系统中质量与成本的问题,提出一种在机检测夹具间接影响质量与成本的求解方式。在该求解方式中,分析了在机检测夹具变量误差的特点,采用状态空间法建立了误差传递模型;分析了在机检测夹具的成本,采用显著性检验的方法建立了检测成本模型,并将检测成本融入包含公差成本和质量损失成本的成本模型中。在此基础上,提出以成本模型为目标函数、误差传递模型为约束条件的优化函数,找出零件满足质量的最优成本。以两类零件加工的质量成本为例,验证了在机检测夹具方式的有效性。 展开更多
关键词 五轴加工 串并联多工序 状态空间方程统计特征 在线检测成本
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分水板固定机构的创新设计研究
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作者 徐世福 王超 +1 位作者 蒋亚南 程子川 《机械研究与应用》 2019年第3期79-81,84,共4页
水槽是现代厨房必不可少的器具。目前市面上的水槽在针对不同大小的蔬菜或水果的清洗过程中,会因清洗对象体积不同而产生过量用水或清洗不充分现象。因此提出一种可调节水槽,基于特征状态空间方法设计分水板固定机构,实现水槽体积大小... 水槽是现代厨房必不可少的器具。目前市面上的水槽在针对不同大小的蔬菜或水果的清洗过程中,会因清洗对象体积不同而产生过量用水或清洗不充分现象。因此提出一种可调节水槽,基于特征状态空间方法设计分水板固定机构,实现水槽体积大小的改变。将手动旋转转化为输入运动特征矢量,压紧板的固定压紧运动转化为输出运动特征矢量,建立相应运动特征状态变化方程。通过对运动特征状态变换矩阵的分解与匹配,解得112种机械运动方案。基于运动链的拓扑性能评价选出两种方案作为设计结果。 展开更多
关键词 特征状态空间方法 分水板 运动方案设计 运动链
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State Space-Time and Four States of Universe 被引量:5
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作者 Jinzhong Yan 《Journal of Physical Science and Application》 2013年第2期127-134,共8页
All things in the universe possess a state and characteristics of state, resultantly in presence of space-time, which is perceived by human beings. An outlook of space-time is shaped in human by perceiving the existen... All things in the universe possess a state and characteristics of state, resultantly in presence of space-time, which is perceived by human beings. An outlook of space-time is shaped in human by perceiving the existence and change of objects. The state space is all state characteristics exhibited in objects whilst the state time refers to the duration of an object's state. The time is a spatial property and not an independent dimension. The state space-time is a unity of internal and external space-time. The internal space-time is stemmed from the overall internal forces and internal energies and is a covert space-time. The external space-time refers to a space-time manifested by the external characteristics and movement of an object and is an overt space-time. In physics, there are four kinds of forces and four state space-times: bonding force and three-dimensional space-time; strong interaction of exchangeable n meson and two-dimensional space-time; quark confinement and one-dimensional space-time; and weak interaction and zero-dimensional space-time. The universe is constituted by dissimilar state space-times. Newton space-time is a three-dimensional state space-time; Einstein's theory of relativity is a two-dimensional state space-time. Newton and Einstein were different observers. Temporal and spatial perception of human is dependent upon human's intemal energy and quality. Through Qigong exercises, the human is able to enter the three-dimensional, two-dimensional, one-dimensional and zero-dimensional space-times. The relativity theory of human body will solve the time problems at the interplanetary voyage of astronauts. 展开更多
关键词 State space-time UNIVERSE four states.
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六相双Y移30°感应电机稳定性分析 被引量:2
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作者 梅仕锋 欧阳红林 杨民生 《电机技术》 2006年第1期35-37,共3页
以六相双Y移30°感应电机为对象,从建立电机数学模型入手,导出状态空间方程,应用特征值稳定判据分析多相感应电机的稳定性。该方法适合线性化的系统在稳定工作点附近微小振动的稳定性分析。针对电机定、转子参数和转动惯量的变化,... 以六相双Y移30°感应电机为对象,从建立电机数学模型入手,导出状态空间方程,应用特征值稳定判据分析多相感应电机的稳定性。该方法适合线性化的系统在稳定工作点附近微小振动的稳定性分析。针对电机定、转子参数和转动惯量的变化,对系统稳定性进行实例计算和分析。 展开更多
关键词 六相双Y移30° 感应电机 稳定性 状态空间方程特征
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Real-time road traffic states estimation based on kernel-KNN matching of road traffic spatial characteristics 被引量:2
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作者 XU Dong-wei 《Journal of Central South University》 SCIE EI CAS CSCD 2016年第9期2453-2464,共12页
The accurate estimation of road traffic states can provide decision making for travelers and traffic managers. In this work,an algorithm based on kernel-k nearest neighbor(KNN) matching of road traffic spatial charact... The accurate estimation of road traffic states can provide decision making for travelers and traffic managers. In this work,an algorithm based on kernel-k nearest neighbor(KNN) matching of road traffic spatial characteristics is presented to estimate road traffic states. Firstly, the representative road traffic state data were extracted to establish the reference sequences of road traffic running characteristics(RSRTRC). Secondly, the spatial road traffic state data sequence was selected and the kernel function was constructed, with which the spatial road traffic data sequence could be mapped into a high dimensional feature space. Thirdly, the referenced and current spatial road traffic data sequences were extracted and the Euclidean distances in the feature space between them were obtained. Finally, the road traffic states were estimated from weighted averages of the selected k road traffic states, which corresponded to the nearest Euclidean distances. Several typical links in Beijing were adopted for case studies. The final results of the experiments show that the accuracy of this algorithm for estimating speed and volume is 95.27% and 91.32% respectively, which prove that this road traffic states estimation approach based on kernel-KNN matching of road traffic spatial characteristics is feasible and can achieve a high accuracy. 展开更多
关键词 road traffic kernel function k nearest neighbor (KNN) state estimation spatial characteristics
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一种变胞式作角机构设计 被引量:5
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作者 郭晓宁 张敏 《机械设计与研究》 CSCD 北大核心 2014年第4期21-23,共3页
针对以单张牛皮纸作为包装材料的半自动纸浆打包机不能实现包装纸的自动折叠问题,运用串联机械系统运动方案设计的特征状态空间方法,结合变胞机构的自适应特性,提出一种变胞式自动包装作角机构,以实现纸浆打包机的包装作角自动化,提高... 针对以单张牛皮纸作为包装材料的半自动纸浆打包机不能实现包装纸的自动折叠问题,运用串联机械系统运动方案设计的特征状态空间方法,结合变胞机构的自适应特性,提出一种变胞式自动包装作角机构,以实现纸浆打包机的包装作角自动化,提高纸浆包装的生产效率。 展开更多
关键词 变胞 特征状态空间 机构综合 作角机构
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ASYMPTOTIC STABILITY AND RIESZ BASIS PROPERTY FOR TREE-SHAPED NETWORK OF STRINGS 被引量:1
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作者 YanniGUO Genqi XU 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2011年第2期225-252,共28页
This paper discusses the asymptotic stability and Riesz basis generation for a general tree-shaped network of vibrating strings. All exterior vertices are assumed to be fixed and interior vertices are imposed linear d... This paper discusses the asymptotic stability and Riesz basis generation for a general tree-shaped network of vibrating strings. All exterior vertices are assumed to be fixed and interior vertices are imposed linear damping feedbacks. This paper shows that the system is well-posed and asymptotically stable by C0-semigroup theory. With some additional conditions, the spectrum of the system is shown to be located in a strip that is parallel to the imaginary axis and the set of all generalized eigenfunctions is completed in the state space. These lead to the conclusion that there is a sequence of generalized eigenfunctions of the system, which forms a Riesz basis with parenthesis for the state space. 展开更多
关键词 COMPLETENESS network of strings riesz basis with parentheses stability.
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Bi-dimension decomposed hidden Markov models for multi-person activity recognition
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作者 Wei-dong ZHANG Feng CHEN Wen-li XU 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2009年第6期810-819,共10页
We present a novel model for recognizing long-term complex activities involving multiple persons. The proposed model, named ‘decomposed hidden Markov model’ (DHMM), combines spatial decomposition and hierarchical ab... We present a novel model for recognizing long-term complex activities involving multiple persons. The proposed model, named ‘decomposed hidden Markov model’ (DHMM), combines spatial decomposition and hierarchical abstraction to capture multi-modal, long-term dependent and multi-scale characteristics of activities. Decomposition in space and time offers conceptual advantages of compaction and clarity, and greatly reduces the size of state space as well as the number of parameters. DHMMs are efficient even when the number of persons is variable. We also introduce an efficient approximation algorithm for inference and parameter estimation. Experiments on multi-person activities and multi-modal individual activities demonstrate that DHMMs are more efficient and reliable than familiar models, such as coupled HMMs, hierarchical HMMs, and multi-observation HMMs. 展开更多
关键词 Multi-channel setting Hierarchical modeling Hidden Markov model Activity recognition
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A geometric interpretation of the transition density of a symmetric Lévy process
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作者 JACOB Niels KNOPOVA Victorya +1 位作者 LANDWEHR Sandra SCHILLING RenéL. 《Science China Mathematics》 SCIE 2012年第6期1099-1126,共28页
We study for a class of symmetric Levy processes with state space R^n the transition density pt(x) in terms of two one-parameter families of metrics, (dt)t〉o and (δt)t〉o. The first family of metrics describes... We study for a class of symmetric Levy processes with state space R^n the transition density pt(x) in terms of two one-parameter families of metrics, (dt)t〉o and (δt)t〉o. The first family of metrics describes the diagonal term pt (0); it is induced by the characteristic exponent ψ of the Levy process by dr(x, y) = √tψ(x - y). The second and new family of metrics 6t relates to √tψ through the formula exp(-δ^2t(x,y))=F[e^-tψ/pt(0)](x-y),where Y denotes the Fourier transform. Thus we obtain the following "Gaussian" representation of the tran- sition density: pt(x) = pt(O)e^-δ^2t(x,0) where pt(O) corresponds to a volume term related to √tψ and where an "exponential" decay is governed by 5t2. This gives a complete and new geometric, intrinsic interpretation of pt(x). 展开更多
关键词 transition function estimates Levy processes metric measure spaces heat kernel bounds in-finitely divisible distributions self-reciprocal distributions
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