Relay movement control for maintaining connectivity in aeronautical ad hoc networks

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.

Modelling and Simulation for Train Movement Control Using Car-Following Strategy

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.

Control strategy of central pattern generator gait movement under condition of attention selection

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.

The Modulation and Control of the Gecko's Foot Movement

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.

Controlled Movements in Superlubric MEMS

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.

Identification of Information-Seeking Behaviors from Air Traffic Controllers′ Eye Movements

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.

SIMULATING RHYTHMIC MOVEMENT OF HUMAN ELBOW JOINT USING A NEURAL NETWORK PREDICTIVE MODEL

Human brain is hypothesized to store a geometry and dynamic model of the limb.A multilayer perceptron (or MLP) network is used to stand for the model.In this paper the human elbow joint rhythmic movement is simulated in three cases:1)Parameters of the MLP,the limb geometry and dynamic model match completely,2)Parameters mismatch between them,and 3)Disturbance exists.The results show that parameters mismatch is the main error source,which causes the elbow joint movement to be aberrant.From this we can infer that movement study is a process in which the internal model is updated continuously to match the geometry and dynamic model of limb.

信息搜索策略对DCS排险绩效的影响——认知负荷的中介效应研究

为探究在集散式控制系统(distributed control system,DCS)危险排除过程中控制员不同信息搜索策略对排险任务绩效的影响及认知负荷的中介效应,基于虚拟现实技术、皮肤电采样和眼动追踪技术构建模拟DCS工控平台,招募20名相关专业被试参与模拟排险实验并对其认知负荷及排险绩效进行量化,使用眼动轨迹匹配法判断被试的信息搜索模式,研究认知负荷的中介效应及中介机理。研究结果表明:不同信息搜索策略会显著影响任务绩效;认知负荷对该影响的中介效应高达89.66%,表明信息搜索策略主要通过影响认知负荷来间接作用于排险任务绩效,认知负荷越高,任务绩效越低;逻辑系统搜索策略能通过高效图式匹配减少认知资源消耗,显著抑制认知负荷增长,任务绩效表现最佳;空间系统搜索较难抑制认知负荷,任务绩效较差;随机搜索被试认知负荷显著高于其他组,绩效表现最差;此外,不同认知负荷水平下被试的信息搜索策略没有明显转变倾向。研究结果可为DCS控制人员的考核和培训提供理论支撑。

受限空间环境下的架桥机横移架梁施工技术研究

针对狭窄空间和特殊地形条件下架桥机的横向移传与放置桥梁节段所面临的技术挑战展开了深入探讨与分析,并通过对多个城市轨道交通项目进行采样分析,构建了模拟横移架梁过程的精确数值模型,确立了横移过程中的关键影响因子,同时,对于特异性地质与空间限制条件,创新性地提出了一套模块化横移支架系统,该系统具备快速组装融合与位置精确调整的优势,显著提升了在受限空间内的架梁工作效率和可行性。

矸石胶结充填体力学特性及充填效应研究

传统的垮落法采空区处理方式造成岩层大范围移动破坏、地表沉陷变形等生态环境问题不断发生。地下煤炭采出后顶板发生破碎、垮冒现象,在覆岩压力作用下各岩层移动不断活化、破断,进而向地表方向发展形成地面沉陷和破坏,由此引发了水土流失、地下水断流、地表建筑物破坏、居民搬迁等一系列问题。结合煤矿矸石胶结充填开采技术的特点,在研究胶结充填材料力学特性的基础上,深入研究矸石胶结充填采煤采场顶板岩层受力、移动、变形规律以及采空区充填率对采空区上覆岩层活动的影响等方面。研究成果矸石胶结充填技术既能够充分利用固废,减少煤矸石及粉煤灰给环境带来的污染问题,而且保护地面建筑物稳定不破坏,对于解决“三下”压煤问题具有极高的应用价值,为充填开采采场矿压规律、上覆岩层移动控制、矸石胶结充填材料选择设计、地表沉陷预计等方面提供理论依据和技术支持,进一步丰富和完善充填开采基础理论,有利于促进充填开采技术的推广应用。

基于阻抗控制的钢筋绑扎机器人横向移动控制

当前建筑业仍然是劳动密集型产业,工地作业往往有较高的强度和重复性,其中以钢筋绑扎工序为最。因此,为了节省了人力资源,降低工人劳动强度,以轮腿式钢筋绑扎机器人为平台,对其横向运动控制展开研究,提出了一种基于阻抗控制的横向移动控制。采用雅可比矩阵法对机器人横向移动机构进行了运动学分析,采用拉格朗日法对其进行了动力学分析。实验采用阻抗控制使机器人适应横向移动带来的冲击,阻抗控制所跟踪S型曲线轨迹使机器人运动更加柔顺。实验观测和结果表明,机器人运动平稳,横向移动机构两侧同步性较高,力矩输出符合预期,完全实现了机器人在钢筋网面的横向移动。为钢筋绑扎机器人的运动控制提供了一个可行且实用的解决方案。

Modeling and simulation of high-speed passenger train movements in the rail line

In this paper, we propose a new formula of the real-time minimum safety headway based on the relative velocity of consecutive trains and present a dynamic model of high-speed passenger train movements in the rail line based on the proposed formula of the minimum safety headway. Moreover, we provide the control strategies of the high-speed passenger train operations based on the proposed formula of the real-time minimum safety headway and the dynamic model of highspeed passenger train movements. The simulation results demonstrate that the proposed control strategies of the passenger train operations can greatly reduce the delay propagation in the high-speed rail line when a random delay occurs.

Smoke movement in a tunnel of a running metro train on fire

Research on the distribution of smoke in tunnels is significant for the fire emergency rescue after an operating metro train catches fire. A dynamic grid technique was adopted to research the law of smoke flow diffusion inside the tunnel when the bottom of a metro train was on fire and to compare the effect of longitudinal ventilation modes on the smoke motion when the burning train stopped. Research results show that the slipstream curves around the train obtained by numerical simulation are consistent with experimental data. When the train decelerates, the smoke flow first extends to the tail of the train. With the decrease of the train's speed, the smoke flow diffuses to the head of the train. After the train stops, the slipstream around the train formed in the process of train operation plays a leading role in the smoke diffusion in the tunnel. The smoke flow quickly diffuses to the domain in front of the train. After forward mechanical ventilation is provided, the smoke flow inside the tunnel continues to diffuse downstream. When reverse mechanical ventilation operates, the smoke in front of the train flows back rapidly and diffuses to the rear of the train.

Multiscale entropy:A tool for understanding the complexity of postural control

Clinical disorders often are characterized by a breakdown in dynamical processes that contribute to the control of upright standing.Disruption to a large number of physiological processes operating at different time scales can lead to alterations in postural center of pressure(Co P)fluctuations.Multiscale entropy(MSE) has been used to identify differences in fluctuations of postural Co P time series between groups with and without known physiological impairments at multiple time scales.The purpose of this paper is to:1) review basic elements and current developments in entropy techniques used to assess physiological complexity;and 2) identify how MSE can provide insights into the complexity of physiological systems operating at multiple time scales that underlie the control of posture.We review and synthesize evidence from the literature providing support for MSE as a valuable tool to evaluate the breakdown in the physiological processes that accompany changes due to aging and disease in postural control.This evidence emerges from observed lower MSE values in individuals with multiple sclerosis,idiopathic scoliosis,and in older individuals with sensory impairments.Finally,we suggest some future applications of MSE that will allow for further insight into how physiological deficits impact the complexity of postural fluctuations;this information may improve the development and evaluation of new therapeutic interventions.

Adaptability of anticipatory postural adjustments associated with voluntary movement

The control of balance is crucial for efficiently performing most of our daily motor tasks, such as those involving goal-directed arm movements or whole body displacement. The purpose of this article is twofold. Firstly, it is to recall how balance can be maintained despite the different sources of postural perturbation arising during voluntary movement. The importance of the so-called "anticipatory postural adjustments"(APA), taken as a "line of defence" against the destabilizing effect induced by a predicted perturbation, is emphasized. Secondly, it is to report the results of recent studies that questioned the adaptability of APA to various constraints imposed on the postural system. The postural constraints envisaged here are classified into biomechanical(postural stability, superimposition of motor tasks),(neuro) physiological(fatigue), temporal(time pressure) and psychological(fear of falling, emotion). Overall, the results of these studies point out the capacity of the central nervous system(CNS) to adapt the spatio-temporal features of APA to each of theseconstraints. However, it seems that, depending on the constraint, the "priority" of the CNS was focused on postural stability maintenance, on body protection and/or on maintenance of focal movement performance.

MECHANICAL ANALYSIS OF ORBIT TRACKING MOVEMENT OF FEED SYSTEM IN LARGE SPHERICAL RADIO-TELESCOPE

The curve equation and its mechanics analysis of suspended-cable under the condition of end load are given. Then on the basis of it, the mechanical analysis of suspended-cable system for large spherical radio-telescope is studied, and procedures of the control for the orbit tracking movement of the line feed in large spherical radiotelescope are given. The validity of the results mentioned above is confirmed by means of computer simulations.

Electromyography Control of a Computer Model of the Arm

Human arm movements may be adversely affected in the event of stroke or spinal cord injuries, eventually causing the patient to lose control of arm movements. Electromyography (EMG) is con-sidered the most effective technique for the restoration of arm movement in such cases. The reha-bilitation period for such patients is usually long. Moreover, complex treatment techniques may demoralize them. Therefore, this study, attempts to contribute to the development of a relaxing rehabilitation environment through electromyography control of a computer model of the arm. The model is created using MATLAB? and Data LINK software and other requisite components for training the targeted participants to control their arm movements. Six male participants with no history of injury to the arms or back were selected using the set protocol. The results and data collected are analysed using three performance measures i.e. the number of target hits, average time to target, and path efficiency for each target. Then, the main results in terms of the obtained performance measures are discussed and compared with those of previous studies.

Sea surface temperature data from coastal observation stations:quality control and semidiurnal characteristics

Sea surface temperature(SST)data obtained from coastal stations in Jiangsu,China during 20102014 are quality controlled before analysis of their characteristic semidiurnal and seasonal cycles,including the correlation with the variation of the tide.Quality control of data includes the validation of extreme values and checking of hourly values based on temporally adjacent data points,with 0.15℃/h considered a suitable threshold for detecting abnormal values.The diurnal variation amplitude of the SST data is greater in spring and summer than in autumn and winter.The diurnal variation of SST has bimodal structure on most days,i.e.,SST has a significant semidiurnal cycle.Moreover,the semidiurnal cycle of SST is negatively correlated with the tidal data from March to August,but positively correlated with the tidal data from October to January.Little correlation is detected in the remaining months because of the weak coastal offshore SST gradients.The quality control and understanding of coastal SST data are particularly relevant with regard to the validation of indirect measurements such as satellite-derived data.

新型列控系统列车行车许可CTC显示方案研究

调度集中(CTC)系统中的列车运行状态信息实时显示功能可帮助列车调度人员高效开展行车指挥。新型列控系统下列车采取移动闭塞方式运行,既有CTC系统中的列车行车许可显示无法准确反映列车运行情况,为此需要对列车行车许可在CTC系统中的显示与更新方案进行研究。通过提取列车精准位置信息,分别研究列车位于站内和站间两种情况下行车许可显示范围计算方法,并根据行车许可显示范围计算显示光带的起止点,从而实现列车位置和行车许可范围在CTC终端界面的实时显示及更新。该方案在CTC仿真测试平台及现场试验线路上进行了验证,满足新型列控系统下调度集中系统中列车运行状态信息显示的规范要求,能够准确及时地反映列车运行状态,有利于提升列车调度指挥的准确性和效率。