The modulation and control of gecko＇s foot movements were studied electrophysiologically in order to design the motor control system of a gecko-mimic robot. In this study （1） the anatomy of the peripheral nerves co...The modulation and control of gecko＇s foot movements were studied electrophysiologically in order to design the motor control system of a gecko-mimic robot. In this study （1） the anatomy of the peripheral nerves controlling the gecko＇s foot movements was determined; （2） the relationship between the limb nerves of the gecko and its foot motor patterns was studied; （3） the afferent impulses of the nerves evoked by rubbing the gecko＇s toes and palm were recorded; （4） copying the natural patterns of movement of the gecko＇s foot （abduction, adduction, flexion, and revolution） and its limb nerve modulation and control mechanism, the nerves were stimulated under computer control, and the results recorded by CCD. Results suggest that gecko＇s foot movements can be successfully controlled by artificial electrical signals.展开更多
As a typical rhythmic movement, human being＇s rhythmic gait movement can be generated by a central pattern generator （CPG） located in a spinal cord by self- oscillation. Some kinds of gait movements are caused by g...As a typical rhythmic movement, human being＇s rhythmic gait movement can be generated by a central pattern generator （CPG） located in a spinal cord by self- oscillation. Some kinds of gait movements are caused by gait frequency and amplitude variances. As an important property of human being＇s motion vision, the attention selection mechanism plays a vital part in the regulation of gait movement. In this paper, the CPG model is amended under the condition of attention selection on the theoretical basis of Matsuoka neural oscillators. Regulation of attention selection signal for the CPG model parameters and structure is studied, which consequentially causes the frequency and amplitude changes of gait movement output. Further, the control strategy of the CPG model gait movement under the condition of attention selection is discussed, showing that the attention selection model can regulate the output model of CPG gait movement in three different ways. The realization of regulation on the gait movement frequency and amplitude shows a variety of regulation on the CPG gait movement made by attention selection and enriches the controllability of CPG gait movement, which demonstrates potential influence in engineering applications.展开更多
As a new sort of mobile ad hoc network(MANET), aeronautical ad hoc network(AANET) has fleet-moving airborne nodes(ANs) and suffers from frequent network partitioning due to the rapid-changing topology. In this work, t...As a new sort of mobile ad hoc network(MANET), aeronautical ad hoc network(AANET) has fleet-moving airborne nodes(ANs) and suffers from frequent network partitioning due to the rapid-changing topology. In this work, the additional relay nodes(RNs) is employed to repair the network and maintain connectivity in AANET. As ANs move, RNs need to move as well in order to re-establish the topology as quickly as possible. The network model and problem definition are firstly given, and then an online approach for RNs' movement control is presented to make ANs achieve certain connectivity requirement during run time. By defining the minimum cost feasible moving matrix(MCFM), a fast algorithm is proposed for RNs' movement control problem. Simulations demonstrate that the proposed algorithm outperforms other control approaches in the highly-dynamic environment and is of great potential to be applied in AANET.展开更多
Based on optimM velocity car-following model, in this paper, we propose a new railway tramc model for describing the process of train movement control. In the proposed model, we give an improved form of the optimal ve...Based on optimM velocity car-following model, in this paper, we propose a new railway tramc model for describing the process of train movement control. In the proposed model, we give an improved form of the optimal velocity function V^opt, which is considered as the desired velocity function for train movement control under different control conditions. In order to test the proposed model, we simulate and analyze the trajectories of train movements, moreover, discuss the relationship curves between the train allowable velocity and the site of objective point in detail. Analysis results indicate that the proposed model can well capture some realistic futures of train movement control.展开更多
Structural superlubricity(SSL)refers to a state where the friction and wear between two directly contacted solid surfaces are virtually zero.The realization of microscale SSL in 2012 rapidly explored SSL technologies ...Structural superlubricity(SSL)refers to a state where the friction and wear between two directly contacted solid surfaces are virtually zero.The realization of microscale SSL in 2012 rapidly explored SSL technologies which hold great potential in the development of reliable and energy⁃efficient micro devices.A key to a successful superlubric device is to control the movements of the superlubric slider.To solve this challenge,here two general principles are shown to guide and control the motion of the slider,i.e.,by minimization of interfacial energy and minimization of electrostatic energy.When the shapes of the slider and substrate are designed appropriately,the excess interfacial energy of the contact⁃pair provides restoring and constraining forces to the slider.Similarly,tunable driving and constraining forces are enabled by the electric fields induced by the electrodes buried in the substrate.These concepts are demonstrated on the design of a superlubric resonator whose natural frequency of the lateral translational mode is well⁃defined and unfavorable rotation is constrained.The above design principles should be applicable to superlubric devices in general and help the development of future applications of structural superlubricity.展开更多
In this paper the definitions of generalized transfer functios of control system and itscontinuity are presented.Using generalized transfer function as a tool,a set of theorems fordeciding movement stability have been...In this paper the definitions of generalized transfer functios of control system and itscontinuity are presented.Using generalized transfer function as a tool,a set of theorems fordeciding movement stability have been constructed.Thus basing understanding of thecharacteristics of a control dynamics system on its measured procedure will simplify thedecision method of movement stability problems.展开更多
Air traffic controllers are the important parts of air traffic management system who are responsible for the safety and efficiency of the system.They make traffic management decisions based on information acquired fro...Air traffic controllers are the important parts of air traffic management system who are responsible for the safety and efficiency of the system.They make traffic management decisions based on information acquired from various sources.The understanding of their information seeking behaviors is still limited.We aim to identify controllers′ behavior through the examination of the correlations between controllers′eye movements and air traffic.Sixteen air traffic controllers were invited to participate real-time simulation experiments,during which the data of their eye ball movements and air traffic were recorded.Tweny-three air traffic complexity metrics and six eye movements metrics were calculated to examine their relationships.Two correlational methods,Pearson′s correlation and Spearman′s correlation,were tested between every eye-traffic pair of metrics.The results indicate that controllers′two kinds of information-seeking behaviors can be identified from their eye movements:Targets tracking,and confliction recognition.The study on controllers′ eye movements may contribute to the understanding of information-seeking mechanisms leading to the development of more intelligent automations in the future.展开更多
车车通信列车运行控制系统中移动授权的生成对城市轨道交通运营效率有着较大的影响。通过分析车车通信列车运行控制系统中移动授权的生成过程及性能,建立基于有色Petri网(colored Petri net,CPN)的车车通信移动授权信息交互的模型,进行...车车通信列车运行控制系统中移动授权的生成对城市轨道交通运营效率有着较大的影响。通过分析车车通信列车运行控制系统中移动授权的生成过程及性能,建立基于有色Petri网(colored Petri net,CPN)的车车通信移动授权信息交互的模型,进行性能分析。研究移动授权生成过程中端对端通信传输时延的延时概率,根据不同信道质量下统计传输时延的平均值,计算移动授权完成的成功率。分析结果表明,基于车车通信的列车运行控制系统移动授权的生成过程,符合地铁长期演进(long term evolution for metro,LTE-M)系统端到端延时时间不大于150 ms的概率不小于98%,时延随着信道质量的下降而增加。展开更多
基金This work was funded by Hi-tech Research and Development Program of China(2002AA 423230)National Natural Science Foundation of China(90205014,30400086).
文摘The modulation and control of gecko＇s foot movements were studied electrophysiologically in order to design the motor control system of a gecko-mimic robot. In this study （1） the anatomy of the peripheral nerves controlling the gecko＇s foot movements was determined; （2） the relationship between the limb nerves of the gecko and its foot motor patterns was studied; （3） the afferent impulses of the nerves evoked by rubbing the gecko＇s toes and palm were recorded; （4） copying the natural patterns of movement of the gecko＇s foot （abduction, adduction, flexion, and revolution） and its limb nerve modulation and control mechanism, the nerves were stimulated under computer control, and the results recorded by CCD. Results suggest that gecko＇s foot movements can be successfully controlled by artificial electrical signals.
基金supported by the National Natural Science Foundation of China(Nos.11232005 and11472104)the Doctoral Fund of Ministry of Education of China(No.20120074110020)
文摘As a typical rhythmic movement, human being＇s rhythmic gait movement can be generated by a central pattern generator （CPG） located in a spinal cord by self- oscillation. Some kinds of gait movements are caused by gait frequency and amplitude variances. As an important property of human being＇s motion vision, the attention selection mechanism plays a vital part in the regulation of gait movement. In this paper, the CPG model is amended under the condition of attention selection on the theoretical basis of Matsuoka neural oscillators. Regulation of attention selection signal for the CPG model parameters and structure is studied, which consequentially causes the frequency and amplitude changes of gait movement output. Further, the control strategy of the CPG model gait movement under the condition of attention selection is discussed, showing that the attention selection model can regulate the output model of CPG gait movement in three different ways. The realization of regulation on the gait movement frequency and amplitude shows a variety of regulation on the CPG gait movement made by attention selection and enriches the controllability of CPG gait movement, which demonstrates potential influence in engineering applications.
文摘As a new sort of mobile ad hoc network(MANET), aeronautical ad hoc network(AANET) has fleet-moving airborne nodes(ANs) and suffers from frequent network partitioning due to the rapid-changing topology. In this work, the additional relay nodes(RNs) is employed to repair the network and maintain connectivity in AANET. As ANs move, RNs need to move as well in order to re-establish the topology as quickly as possible. The network model and problem definition are firstly given, and then an online approach for RNs' movement control is presented to make ANs achieve certain connectivity requirement during run time. By defining the minimum cost feasible moving matrix(MCFM), a fast algorithm is proposed for RNs' movement control problem. Simulations demonstrate that the proposed algorithm outperforms other control approaches in the highly-dynamic environment and is of great potential to be applied in AANET.
基金Supported by the National Natural Science Foundation of China under Grant Nos.60634010 and 60776829the State Key Laboratory of Rail Traffic Control and Safety (Contract No.RCS2008ZZ001 and RCS2010ZZ001),Beijing Jiaotong University
文摘Based on optimM velocity car-following model, in this paper, we propose a new railway tramc model for describing the process of train movement control. In the proposed model, we give an improved form of the optimal velocity function V^opt, which is considered as the desired velocity function for train movement control under different control conditions. In order to test the proposed model, we simulate and analyze the trajectories of train movements, moreover, discuss the relationship curves between the train allowable velocity and the site of objective point in detail. Analysis results indicate that the proposed model can well capture some realistic futures of train movement control.
基金National Natural Science Foundation of China(Grant Nos.11572173,11890671,51961145304 and 11921002)the National Key Basic Research Program of China(Grant No.2013CB934200)+3 种基金the Cyrus Tang Foundation(Grant No.202003)the Beijing Municipal Science&Technology Commission(Grant No.Z151100003315008)the Tsinghua University Initiative Scientific Research(Grant Nos.2014Z01007 and 2012Z01015)the State Key Laboratory of Tribology Tsinghua University Initiative Scientific Research(Grant No.SKLT2019D02).
文摘Structural superlubricity(SSL)refers to a state where the friction and wear between two directly contacted solid surfaces are virtually zero.The realization of microscale SSL in 2012 rapidly explored SSL technologies which hold great potential in the development of reliable and energy⁃efficient micro devices.A key to a successful superlubric device is to control the movements of the superlubric slider.To solve this challenge,here two general principles are shown to guide and control the motion of the slider,i.e.,by minimization of interfacial energy and minimization of electrostatic energy.When the shapes of the slider and substrate are designed appropriately,the excess interfacial energy of the contact⁃pair provides restoring and constraining forces to the slider.Similarly,tunable driving and constraining forces are enabled by the electric fields induced by the electrodes buried in the substrate.These concepts are demonstrated on the design of a superlubric resonator whose natural frequency of the lateral translational mode is well⁃defined and unfavorable rotation is constrained.The above design principles should be applicable to superlubric devices in general and help the development of future applications of structural superlubricity.
文摘In this paper the definitions of generalized transfer functios of control system and itscontinuity are presented.Using generalized transfer function as a tool,a set of theorems fordeciding movement stability have been constructed.Thus basing understanding of thecharacteristics of a control dynamics system on its measured procedure will simplify thedecision method of movement stability problems.
基金supported by the National Natural Science Foundation of China (No.61304190)the Fundamental Research Funds for the Central Universities (No.NJ20150030)the Natural Science Foundation of Jiangsu Province of China (No.BK20130818)
文摘Air traffic controllers are the important parts of air traffic management system who are responsible for the safety and efficiency of the system.They make traffic management decisions based on information acquired from various sources.The understanding of their information seeking behaviors is still limited.We aim to identify controllers′ behavior through the examination of the correlations between controllers′eye movements and air traffic.Sixteen air traffic controllers were invited to participate real-time simulation experiments,during which the data of their eye ball movements and air traffic were recorded.Tweny-three air traffic complexity metrics and six eye movements metrics were calculated to examine their relationships.Two correlational methods,Pearson′s correlation and Spearman′s correlation,were tested between every eye-traffic pair of metrics.The results indicate that controllers′two kinds of information-seeking behaviors can be identified from their eye movements:Targets tracking,and confliction recognition.The study on controllers′ eye movements may contribute to the understanding of information-seeking mechanisms leading to the development of more intelligent automations in the future.
文摘车车通信列车运行控制系统中移动授权的生成对城市轨道交通运营效率有着较大的影响。通过分析车车通信列车运行控制系统中移动授权的生成过程及性能,建立基于有色Petri网(colored Petri net,CPN)的车车通信移动授权信息交互的模型,进行性能分析。研究移动授权生成过程中端对端通信传输时延的延时概率,根据不同信道质量下统计传输时延的平均值,计算移动授权完成的成功率。分析结果表明,基于车车通信的列车运行控制系统移动授权的生成过程,符合地铁长期演进(long term evolution for metro,LTE-M)系统端到端延时时间不大于150 ms的概率不小于98%,时延随着信道质量的下降而增加。
