Theoretical and Experimental Quantification of Solar Radiation through a Tracking System

This work deals with the estimation of solar radiation through a solar tracker aimed at evaluating the effect of solar tracking on the solar deposit in Burkina Faso. Using a two-axis solar tracking system, we experimentally measured solar radiation at our Joseph KI-ZERBO University site and compared it with that obtained by a numerical simulation run using Fortran programming software based on a mathematical model by Brichambaut. The results obtained from the mathematical and experimental studies show that, with a solar tracker, on a clear-sky day, solar irradiation is between 800 W·m−2 and 1000 W·m−2 between about 8 a.m. and 4 p.m., i.e. a duration of 8 hours of insolation. Analysis of the numerical and experimental results shows very good quantitative and qualitative agreement, with an average relative error of 18%.

Economic Feasibility Assessment of Motorized PV Louver System Considering the Near Shading Parameter, Array Incidence Losses and Other Environmental Factors

Seoul has good weather settings for incorporating renewable energies, hence, given its small land area living mode was mostly set in an apartment condition it is an ideal place for building applied photovoltaic (BAPV) for solar energy harvesting. On the other hand, the BAPV energy self-consumption hasn’t been thoroughly examined considering the overall energy consumption requirement. Therefore, presented in this communication are the viability of PVL to produce electricity from solar energy and insights on modulating and improving energy harvesting efficiency. To accomplish this objective, three major factors were considered: 1) the photovoltaic (PV) positioning;2) the solar tracking scenario;and 3) the mechanistic system energy consumption. The overall louver energy generation was thoroughly scrutinized from the net energy conception of the BAPV up to the mechanistic module energy expenditure. This work intends to provide insights into the economic feasibility of BAPV assessing its technological profitability in the specified location and building size.

Theoretical Comparative Energy Efficiency Analysis of Dual Axis Solar Tracking Systems

This paper developed a theoretical model substantially based on the principle that only the normal component of solar radiation is actually converted into electrical energy. This theoretical model helped to predict minimum and maximum daily energy gain (compared to static PV system tilted with certain angle) when using dual axis PV solar tracking systems, at any given location on earth without prior experimental data. Based on equations derived from model, minimum and maximum energy gain is computed and summarized in tables of minimum and maximum. Furthermore, the model equations could be used to set up future experimental studies related to the matter.

Trajectory tracking guidance of interceptor via prescribed performance integral sliding mode with neural network disturbance observer

This paper investigates interception missiles’trajectory tracking guidance problem under wind field and external disturbances in the boost phase.Indeed,the velocity control in such trajectory tracking guidance systems of missiles is challenging.As our contribution,the velocity control channel is designed to deal with the intractable velocity problem and improve tracking accuracy.The global prescribed performance function,which guarantees the tracking error within the set range and the global convergence of the tracking guidance system,is first proposed based on the traditional PPF.Then,a tracking guidance strategy is derived using the integral sliding mode control techniques to make the sliding manifold and tracking errors converge to zero and avoid singularities.Meanwhile,an improved switching control law is introduced into the designed tracking guidance algorithm to deal with the chattering problem.A back propagation neural network(BPNN)extended state observer(BPNNESO)is employed in the inner loop to identify disturbances.The obtained results indicate that the proposed tracking guidance approach achieves the trajectory tracking guidance objective without and with disturbances and outperforms the existing tracking guidance schemes with the lowest tracking errors,convergence times,and overshoots.

Trajectory Tracking for MmWave Communication Systems via Cooperative Passive Sensing

A cooperative passive sensing framework for millimeter wave(mmWave)communication systems is proposed and demonstrated in a scenario with one mobile signal blocker.Specifically,in the uplink communication with at least two transmitters,a cooperative detection method is proposed for the receiver to track the blocker’s trajectory,localize the transmitters and detect the potential link blockage jointly.To facilitate detection,the receiver collects the signal of each transmitter along a line-of-sight(LoS)path and a non-line-of-sight(NLoS)path separately via two narrow-beam phased arrays.The NLoS path involves scattering at the mobile blocker,allowing its identification through the Doppler frequency.By comparing the received signals of both paths,the Doppler frequency and angle-of-arrival(AoA)of the NLoS path can be estimated.To resolve the blocker’s trajectory and the transmitters’locations,the receiver should continuously track the mobile blocker to accumulate sufficient numbers of the Doppler frequency and AoA versus time observations.Finally,a gradient-descent-based algorithm is proposed for joint detection.With the reconstructed trajectory,the potential link blockage can be predicted.It is demonstrated that the system can achieve decimeterlevel localization and trajectory estimation,and predict the blockage time with an error of less than 0.1 s.

Probe into the double track system reform of the old age insurance system

In recent years, with the development of socialist market economy is gradually perfect, the endowment insurance system gradually affects people＇s daily life, the old-age insurance benefits of the ＂dual track＂ operation of the drawbacks caused by more and more people＇s attention, so the old-age insurance system reform, not only is the national endowment for the special requirements of self. It is the realization of China＇s social security reform priority among priorities. Based on the endowment insurance system of endowment insurance system reform, the interpretation of the resistance, found that at present our country how to deal with the problems of merger reform, discuss how to better realize the merger of the pension insurance system.

Influence of matrix physical properties on flow characteristics in dual network model

The tight oil formation develops with microfractures and matrix pores,it is important to study the influence of matrix physical properties on flow characteristics.At first,the representative fracture and matrix samples are selected respectively in the dual media,the fracture and matrix digital rocks are constructed with micro-CT scanning at different resolutions,and the corresponding fracture and matrix pore networks are extracted,respectively.Then,the modified integration method is proposed to build the dual network model containing both fracture and matrix pore-throat elements,while the geometric-topological structure equivalent matrix pores are generated to fill in the skeleton domain of fracture network,the constructed dual network could describe the geometric-topological structure characteristics of fracture and matrix pore-throat simultaneously.At last,by adjusting the matrix pore density and the matrix filling domain factor,a series of dual network models are obtained to analyze the influence of matrix physical properties on flow characteristics in dual-media.It can be seen that the matrix system contributes more to the porosity of the dual media and less to the permeability.With the decrease in matrix pore density,the porosity/permeability contributions of matrix system to dual media keep decreasing,but the decrease is not significant,the oil-water co-flow zone decreases and the irreducible water saturation increases,and the saturation interval dominated by the fluid flow in the fracture keeps increasing.With the decrease in matrix filling domain factor,the porosity/permeability contributions of matrix system to dual media decreases,the oil-water co-flow zone increases and the irreducible water saturation decreases,and the saturation interval dominated by the fluid flow in the fracture keeps increasing.The results can be used to explain the dual-media flow pattern under different matrix types and different fracture control volumes during tight oil production.

DERIVATION AND INTEGRAL SLIDING MODE VARIABLE STRUCTURE CONTROL OF HYDRAULIC VELOCITY TRACKING SYSTEM

The velocity tracking control of a hydraulic servo system is studied. Sincethe dynamics of the system are highly nonlinear and have large extent of model uncertainties, suchas big changes in load and parameters, a derivation and integral sliding mode variable structurecontrol scheme (DI-SVSC) is proposed. An integral controller is introduced to avoid the assumptionthat the derivative of desired signal must be known in conventional sliding mode variable structurecontrol, a nonlinear derivation controller is used to weaken the chattering of system. The designmethod of switching function in integral sliding mode control, nonlinear derivation coefficient andcontrollers of DI-SVSC is presented respectively. Simulation shows that the control approach is ofnice robustness and improves velocity tracking accuracy considerably.

Simulation study on starting of dual clutch transmission for tracked vehicles

In order to study the application of dual clutch transmission （DCT） on tracked vehicles, a simulation moclel and two control methods were performed for starting analysis. Based on a certain transmission of an existing tracked vehicle, a DCT structure was proposed. Matlab/Simulink was a dopted as a platform to develop the simulation model. The engine speed was controlled to follow the target speed as a launch strategy. Two control methods, a proportional integral derivative （ PID ） control method and a fuzzy control method, were proposed to control the engine throttle and oil pressure in order to track the target engine speed. Simulation results show that either the PID control or fuzzy control method can improve the starting performance compared with no loop control meth od. Fuzzy control method can lead a better starting quality compared with PID control method.

Computation of satellite clock-ephemeris augmentation parameters for dual-frequency multi-constellation satellite-based augmentation system

Dual-frequency multi-constellation(DFMC) satellitebased augmentation system(SBAS) does not broadcast fast correction, which is important in reducing range error in L1-only SBAS.Meanwhile, the integrity bound of a satellite at low elevation is so loose that the service availability is decreased near the boundary of the service area. Therefore, the computation of satellite clockephemeris(SCE) augmentation parameters needs improvement.We propose a method introducing SCE prediction to eliminate most of the SCE error resulting from global navigation satellite system GNSS broadcast message. Compared with the signal-inspace(SIS) after applying augmentation parameters broadcast by the wide area augmentation system(WAAS), SIS accuracy after applying augmentation parameters computed by the proposed algorithm is improved and SIS integrity is ensured. With global positioning system(GPS) only, the availability of category-I(CAT-I)with a vertical alert level of 15 m in continental United States is about 90%, while the availability in the other part of the WAAS service area is markedly improved. With measurements made by the stations from the crustal movement observation network of China,users in some part of China can obtain CAT-I(vertical alert limit is 15 m) service with GPS and global navigation satellite system(GLONASS).

Trajectory tracking control of the bionic joint of the musculoskeletal leg mechanism

Pneumatic artificial muscles(PAMs) have properties similar to biological muscles,which are widely used in robotics as actuators.It is difficult to achieve high-precision position control for robotics system driven by PAMs.A 3-DOF musculoskeletal bionic leg mechanism is presented,which is driven by PAMs for quadruped robots.PAM is used to simulate the compliance of biological muscle.The kinematics of the leg swing is derived,and the foot desired trajectory is planned as the sinusoidal functions.The swing experiments of the musculoskeletal leg mechanism are conducted to analyse the extension and flexion of joints.A proportional integral derivative(PID) algorithm is presented for controlling the flexion/extension of the joint.The trajectory tracking results of joints and the PAM gas pressure are obtained.Experimental results show that the developed leg mechanism exhibits good biological properties.

Design, Integration and Characterization of a Tracking Patch: Application to Elderly Monitoring

According to the latest studies, the French population witnesses a high level of elderly. It follows from this phenomenon health troubles, fragility, and for some people suffering from cognitive problems, a daily need of monitoring and tracking in the fugues cases. It is in this context that comes our research program SACHA (Search and Computerize Human Acts). Our ambition is to develop an electronic patch able to trigger alarms, detect falls and provide geolocation service. Our studies were focused on the conception and the integration of different antennas and functionalities of this system in aim to ensure a good compromise “integration/performances”. Several prototypes have been tested and validated in a nursing home.

Application of linear active disturbance rejection control for photoelectric tracking system

Dynamic characteristics and tracking precision are studied in the photoelectric tracking system and a linear active disturbance rejection control( LADRC) scheme is proposed for position loop. A current and speed controller is designed by a transfer function model,which is obtained by adaptive differential evolution. Model error,friction and nonlinear factor existing in position loop are treated as ‘disturbance',which is estimated and compensated by generalized proportional integral( GPI)observer. Comparative results are provided to demonstrate the remarkable performance of the proposed method. It turns out that the proposed scheme is successful and has superior features,such as quick dynamic response,low overshoot and high tracking precision. Furthermore,with the proposed method,friction is suppressed effectively.

基于双通道Residual-LSTM的SINS/GNSS组合导航算法

针对全球导航卫星系统信号中断情况下SINS/GNSS组合导航系统无法持续进行误差校正的问题,提出一种基于双通道Residual-LSTM的SINS/GNSS组合导航算法。首先,考虑到SINS经度、纬度误差传播特性不同所导致的模型输入、输出信息之间的非线性相关性差异化,构建具有不同权重系数的双通道长短期记忆神经网络模型结构,并引入遗忘信息共享机制自适应地利用历史导航数据对经度、纬度信息进行拟合预测。其次,针对深层神经网络存在的模型退化和梯度消失问题,在多层双通道LSTM网络之间建立残差高速通道形成Residual-LSTM模型结构,以增加不同网络层次之间的信息传播路径。最后,通过实船数据验证本文所提算法的有效性。实验结果表明,与基于常规智能方法的SINS/GNSS组合导航算法相比,所提组合导航算法在GNSS信号中断期间经度误差降低了51.97%,纬度误差降低了31.45%。

基于模糊滑模控制的双6-DOF机械臂协同控制方法

目前,双机械臂搬运系统的传统搬运策略存在搬运效果差、双机械臂同步性较差等问题,同时双机械臂的轨迹规划只针对末端轨迹,并未考虑运动状态下机械臂关节处产生的力矩。通过建立UR5机械臂的模型,分析双机械臂搬运状态的运动特点,建立了一种新的基于模糊滑模控制的双机械臂协同控制方法。首先通过对双机械臂建立运动学闭链约束关系,使得双机械臂能够实现期望轨迹运动,其次建立双机械臂的相邻误差交叉耦合同步策略,意在解决双机械臂之间的同步性问题,最后提出的模糊滑模控制策略,通过建立滑模面和滑模趋近律,实现机械臂的轨迹跟踪效果与关节处的控制输入稳定。最后通过对UR5机械臂进行滑模控制仿真,验证了该策略的可行性。

The Feasibility of a Novel Dual-Task Exercise Program Which Integrates Balance, Gaze, Mobility and Cognition in Community Dwelling Older Adults: Protocol for a Randomized Clinical Pilot Trial

Background: Mobility limitations and cognitive impairments which are common with ageing often coexist, causing a reduction in the levels of physical and mental activity and are prognostic of future adverse health events and falls. Consequently, multi-task training paradigms that simultaneously address both mobility and cognition benefit healthy ageing are important to consider in rehabilitation as well as primary prevention. Objectives: An exploratory RCT is being conducted to: a) describe the feasibility and acceptability of the study design and process, procedures, resources and management in two game-based dual-task training programs delivered in the community;b) to explore the lived experiences of the study participants who completed their respective exercise programs. A secondary objective is to obtain preliminary data on the therapeutic effectiveness of the two dual-task training programs. Methods: Thirty healthy older community dwelling participants aged 70 - 85 with previous history of falls will be recruited and randomized to either dual- task treadmill walking (experimental group) or dual-task recumbent bicycle (control group). Data analysis: The qualitative data will be analyzed by two investigators using a content analysis approach. For the quantitative data, outcome measures will be collected pre and post intervention and included measures to assess core balance, spatial-temporal gait variables, visual tracking and cognitive function, as well as, balance and gait analysis under dual-task conditions. Discussion: This research will demonstrate the feasibility of the dual-task training programs in the community, and demonstrate the system’s ability to improve targeted and integrated (dual-task) aspects of balance, mobility, gaze, and cognitive performance. A blended analysis of balance, mobility gaze and cognition will also contribute to a better understanding of the functional consequences of decline in physical and mental skills with age. Trial registration: This pilot clinical trial has been registered at ClinicalTrials.gov Protocol Registration System: NCT01940055.

Analysis of vibration reduction characteristics and applicability of steel-spring floating-slab track

A coupled dynamics computation model for metro vehicles, along with a steel-spring floating-slab track, is developed based on the theory of vehicle-track coupled dynamics. Using the developed model, the influences of the thickness, length and mass of floating-slab, spring rate and its arrangement space, running speed, etc. on the time and frequency domain characteristics of steel-spring fulcrum force are analyzed. The applicability of steel-spring floatingslab track is discussed through two integrated example cases of metro and buildings possessing distinct natural vibra- tion characteristics. It is concluded that, it is quite significant, in the optimization modular design of the parameters of steel-spring floating-slab track, to take the matching relationship of both the amplitude-frequency characteristics of steel-spring fulcrum force and natural vibration characteristics of integrated structures into comprehensive consideration. In this way the expensive steel-spring floating-slab track can be economically and efficiently utilized according to the site condition, and at the same time, the economic losses and bad social impact resulted from the resonance during usage of steel-spring floating-slab track can be avoided.

Robust Fuzzy Tracking Control for Nonlinear Networked Control Systems with Integral Quadratic Constraints

This paper investigates the robust tracking control problcm for a class of nonlinear networked control systems （NCSs） using the Takagi-Sugeno （T-S） fuzzy model approach. Based on a time-varying delay system transformed from the NCSs, an augmented Lyapunov function containing more useful information is constructed. A less conservative sufficient condition is established such that the closed-loop systems stability and time-domain integral quadratic constraints （IQCs） are satisfied while both time-varying network- induced delays and packet losses are taken into account. The fuzzy tracking controllers design scheme is derived in terms of linear matrix inequalities （LMIs） and parallel distributed compensation （PDC）. Furthermore, robust stabilization criterion for nonlinear NCSs is given as an extension of the tracking control result. Finally, numerical simulations are provided to illustrate the effectiveness and merits of the proposed method.

Development Path of Urban-rural Integration

The urban and rural areas are regarded as two major components of the regional economic system. Only through joint balanced development of the two can we achieve overall economic optimization and social welfare maximization. But the great social division of labor has separated urban areas from rural areas,which casts the shadow of city-oriented theory on cooperative relations between urban and rural areas. Mutual separation between urban and rural settlements and independent development trigger off a range of social problems. We must undertake guidance through rational development path of urban-rural integration,to eliminate the phenomenon of urban-rural dual structure,and promote the sustainable development of population,resources and environment in urban and rural areas as soon as possible.

Enhancement of the CO_(2)adsorption and hydrogenation to CH_(4)capacity of Ru–Na–Ca/γ–Al_(2)O_(3)dual function material by controlling the Ru calcination atmosphere

Integrated CO_(2)capture and utilization(ICCU)technology requires dual functional materials(DFMs)to carry out the process in a single reaction system.The influence of the calcination atmosphere on efficiency of 4%Ru-8%Na_(2)CO_(3)-8%CaO/γ-Al_(2)O_(3)DFM is studied.The adsorbent precursors are first co-impregnated onto alumina and calcined in air.Then,Ru precursor is impregnated and four aliquotes are subjected to different calcination protocols:static air in muffle or under different mixtures(10%H_(2)/N_(2),50%H_(2)/N_(2)and N_(2))streams.Samples are characterized by XRD,N_(2)adsorption-desorption,H_(2)chemisorption,TEM,XPS,H_(2)-TPD,H_(2)-TPR,CO_(2)-TPD and TPSR.The catalytic behavior is evaluated,in cycles of CO_(2)adsorption and hydrogenation to CH_(4),and temporal evolution of reactants and products concentrations is analyzed.The calcination atmosphere influences the physicochemical properties and,ultimately,activity of DFMs.Characterization data and catalytic performance discover the acccomodation of Ru nanoparticles disposition and basic sites is mostly influencing the catalytic activity.DFM calcined under N_(2)flow(RuNaCa-N_(2))shows the highest CH_(4)production(449μmol/g at 370℃),because a well-controlled decomposition of precursors which favors the better accomodation of adsorbent and Ru phases,maximizing the specific surface area,the Ru-basic sites interface and the participation of different basic sites in the CO_(2)methanation reaction.Thus,the calcination in a N_(2)flow is revealed as the optimal calcination protocol to achieve highly efficient DFM for integrated CO_(2)adsorption and hydrogenation applications.