An integrated method for identifying the propagation of multi-loop process oscillations and their source location is proposed in this paper. Oscillatory process loop variables are automatically selected based on the c...An integrated method for identifying the propagation of multi-loop process oscillations and their source location is proposed in this paper. Oscillatory process loop variables are automatically selected based on the component-related ratio index and a mixing matrix, both of which are obtained in data preprocessing by spectral independent component analysis. The complex causality among oscillatory process variables is then revealed by Granger causality test and is visualized in the form of causality diagram. The simplification of causal connectivity in the diagram is performed according to the understanding of process knowledge and the final simplest causality diagram, which represents the main oscillation propagation paths, is achieved by the automated cutting-off thresh-old search, with which less significant causality pathways are filtered out. The source of the oscillation disturbance can be identified intuitively through the final causality diagram. Both simulated and real plant data tests are presented to demonstrate the effectiveness and feasibility of the proposed method.展开更多
In confined spaces,conventional ground mobile robots may be unable to reach the target location because of limited maneuvering space or the inability to overcome obstacles.This study presents a ground mobile mechanism...In confined spaces,conventional ground mobile robots may be unable to reach the target location because of limited maneuvering space or the inability to overcome obstacles.This study presents a ground mobile mechanism with a multi-loop reconfigurable trunk(GMMRT)designed to enhance mobility in constrained spaces,such as narrow gaps,ditches,and cross-shaped channels.GMMRT can effectively overcome obstacles in confined spaces through the coordinated motion of its wheels and reconfigurable trunk.Its reconfigurable trunk comprises six limbs and four vertex platforms,forming a versatile,adaptable structure.GMMRT supports two topological structures:wheeled mobility and overall rolling.It features three distinct motion modes:(i)adjusting external dimensions,(ii)performing zero-radius steering,and(iii)overall deformation rolling motion.The kinematic model of GMMRT is established,and its parameters are described using Denavit–Hartenberg parameters.The degrees of freedom under the two topological structures are analyzed on the basis of screw theory.Torque analysis of servo motors is conducted through dynamic analysis.An experimental prototype is designed to validate the three motion modes and servo motor selection,and relevant experiments are performed.Through the development and experimental validation of GMMRT,this work advances mobile robot design for confined spaces and provides a promising approach to overcome the limitations of conventional ground robots.展开更多
In 2005,Gogu,a Frenchman,analyzed 35 different existing formulas for mobility calculation and pointed that the formulas for quick mobility calculation had some limitations and were not general.Therefore,looking for a ...In 2005,Gogu,a Frenchman,analyzed 35 different existing formulas for mobility calculation and pointed that the formulas for quick mobility calculation had some limitations and were not general.Therefore,looking for a general and simple mobility formula is still a hot topic in mechanisms.At the meantime,it is also an important topic to complete the mechanism theory.Gogu proposed a new method that can avoid determining virtual constraints in 2008,but the method is still not general.To solve the problem,this paper defines the new concepts of link-group rank,general-kinematic-pair rank,virtual pair,virtual loop,and virtual-loop rank,and gives a new simple and general formula.Our method converts multi-loop mechanisms into some independent virtual loops,simplifies the problem,avoids calculating virtual constraints,and reduces the calculation difficulty.It is proved that the new formula is simple,general and effective through the mobility analysis of several different kinds of mechanisms.The application of this formula will provide great convenience for general engineers in mobility calculation.展开更多
We construct a class of modules for the twisted multi-loop algebra of type A1 × A1 by applying Wakimoto free bosonic realization. We also discuss the structures and the irreducibility of the Fock space.
针对特高压接入的输电网网架错综复杂、远景适应性差,甚至出现网架规划与开环分区决策相互独立导致资源浪费等问题,该文引入奇异值分解(singular value decomposition,SVD)和特征索引技术,提出了一种考虑电磁环网开环分区和500/220kV典...针对特高压接入的输电网网架错综复杂、远景适应性差,甚至出现网架规划与开环分区决策相互独立导致资源浪费等问题,该文引入奇异值分解(singular value decomposition,SVD)和特征索引技术,提出了一种考虑电磁环网开环分区和500/220kV典型供电结构的输电网多阶段规划方法。首先,提取典型供电结构的路径特征,制定了一种基于标签路径特征的典型供电结构索引策略;然后,构建了一种基于SVD的典型供电结构相似度指标,基于此,以全局典型供电结构相似程度最大为目标,建立了相似度识别规划模型;最后,提出了一种反馈调节机制及求解方法,统筹协调各阶段网架规划和开环分区之间的决策信息。与传统规划方法相比,该文方法不仅能够避免不同阶段开环分区决策导致的资源浪费,还可以减少复杂的规划评估指标计算,构建供电可靠性高、运行方式灵活、远景适应性强的网架结构。基于湖南某地区实际电网算例验证了该文方法的准确性和有效性。展开更多
基金Supported by the National Natural Science Foundation of China （60974061）.
文摘An integrated method for identifying the propagation of multi-loop process oscillations and their source location is proposed in this paper. Oscillatory process loop variables are automatically selected based on the component-related ratio index and a mixing matrix, both of which are obtained in data preprocessing by spectral independent component analysis. The complex causality among oscillatory process variables is then revealed by Granger causality test and is visualized in the form of causality diagram. The simplification of causal connectivity in the diagram is performed according to the understanding of process knowledge and the final simplest causality diagram, which represents the main oscillation propagation paths, is achieved by the automated cutting-off thresh-old search, with which less significant causality pathways are filtered out. The source of the oscillation disturbance can be identified intuitively through the final causality diagram. Both simulated and real plant data tests are presented to demonstrate the effectiveness and feasibility of the proposed method.
基金supported by the Fundamental Research Funds for the Central Universities,China(Grant No.2024JBZX012).
文摘In confined spaces,conventional ground mobile robots may be unable to reach the target location because of limited maneuvering space or the inability to overcome obstacles.This study presents a ground mobile mechanism with a multi-loop reconfigurable trunk(GMMRT)designed to enhance mobility in constrained spaces,such as narrow gaps,ditches,and cross-shaped channels.GMMRT can effectively overcome obstacles in confined spaces through the coordinated motion of its wheels and reconfigurable trunk.Its reconfigurable trunk comprises six limbs and four vertex platforms,forming a versatile,adaptable structure.GMMRT supports two topological structures:wheeled mobility and overall rolling.It features three distinct motion modes:(i)adjusting external dimensions,(ii)performing zero-radius steering,and(iii)overall deformation rolling motion.The kinematic model of GMMRT is established,and its parameters are described using Denavit–Hartenberg parameters.The degrees of freedom under the two topological structures are analyzed on the basis of screw theory.Torque analysis of servo motors is conducted through dynamic analysis.An experimental prototype is designed to validate the three motion modes and servo motor selection,and relevant experiments are performed.Through the development and experimental validation of GMMRT,this work advances mobile robot design for confined spaces and provides a promising approach to overcome the limitations of conventional ground robots.
文摘In 2005,Gogu,a Frenchman,analyzed 35 different existing formulas for mobility calculation and pointed that the formulas for quick mobility calculation had some limitations and were not general.Therefore,looking for a general and simple mobility formula is still a hot topic in mechanisms.At the meantime,it is also an important topic to complete the mechanism theory.Gogu proposed a new method that can avoid determining virtual constraints in 2008,but the method is still not general.To solve the problem,this paper defines the new concepts of link-group rank,general-kinematic-pair rank,virtual pair,virtual loop,and virtual-loop rank,and gives a new simple and general formula.Our method converts multi-loop mechanisms into some independent virtual loops,simplifies the problem,avoids calculating virtual constraints,and reduces the calculation difficulty.It is proved that the new formula is simple,general and effective through the mobility analysis of several different kinds of mechanisms.The application of this formula will provide great convenience for general engineers in mobility calculation.
文摘We construct a class of modules for the twisted multi-loop algebra of type A1 × A1 by applying Wakimoto free bosonic realization. We also discuss the structures and the irreducibility of the Fock space.
文摘针对特高压接入的输电网网架错综复杂、远景适应性差,甚至出现网架规划与开环分区决策相互独立导致资源浪费等问题,该文引入奇异值分解(singular value decomposition,SVD)和特征索引技术,提出了一种考虑电磁环网开环分区和500/220kV典型供电结构的输电网多阶段规划方法。首先,提取典型供电结构的路径特征,制定了一种基于标签路径特征的典型供电结构索引策略;然后,构建了一种基于SVD的典型供电结构相似度指标,基于此,以全局典型供电结构相似程度最大为目标,建立了相似度识别规划模型;最后,提出了一种反馈调节机制及求解方法,统筹协调各阶段网架规划和开环分区之间的决策信息。与传统规划方法相比,该文方法不仅能够避免不同阶段开环分区决策导致的资源浪费,还可以减少复杂的规划评估指标计算,构建供电可靠性高、运行方式灵活、远景适应性强的网架结构。基于湖南某地区实际电网算例验证了该文方法的准确性和有效性。
