首都机场T3航站楼空调系统冷源侧运控策略的研究

针对T3航站楼空调系统冷源侧的气象因素和能耗变化进行分析。首先,分析气象因素对能耗分布及变化的影响;其次通过单位产值综合能耗的对比,分析探索优化运控策略的措施。由于大型单体航站楼的负荷特点相似,对运控策略优化的措施在指导冷源测系统运行上具有一定的参考价值。

Seat inventory control methods for Chinese passenger railways

Railway seat inventory control strategies play a crucial role in the growth of profit and train load factor. The railway passenger seat inventory control problem in China was addressed. Chinese passenger railway operation features and seat inventory control practice were analyzed firstly. A dynamic demand forecasting method was introduced to forecast the coming demand in a ticket booking period. By clustering, passengers' historical ticket bookings were used to forecast the demand to come in a ticket booking period with least squares support vector machine. Three seat inventory control methods: non-nested booking limits, nested booking limits and bid-price control, were modeled under a single-fare class. Different seat inventory control methods were compared with the same demand based on ticket booking data of Train T15 from Beijing West to Guangzhou. The result shows that the dynamic non-nested booking limits control method performs the best, which gives railway operators evidence to adjust the remaining capacity in a ticket booking period.

Athletes who train on unstable compared to stable surfaces exhibit unique postural control strategies in response to balance perturbations

Background:Athletes have been shown to exhibit better balance compared to non-athletes(NON).However,few studies have investigated how the surface on which athletes train affects the strategies adopted to maintain balance.Two distinct athlete groups who experience different types of sport-specific balance training are stable surface athletes(SSA) such as basketball players and those who train on unstable surfaces(USA) such as surfers.The purpose of this study was to investigate the effects of training surface on dynamic balance in athletes compared to NON.Methods:Eight NON,eight SSA,and eight USA performed five 20-s trials in each of five experimental conditions including a static condition and four dynamic conditions in which the support surface translated in the anteroposterior(AP) or mediolateral(ML) planes using positive or negative feedback paradigms.Approximate entropy(Ap En) and root mean square distance(RMS) of the center of pressure(Co P) were calculated for the AP and ML directions.Four 3 × 5(group × condition) repeated measures ANOVAs were used to determine significant effects of group and condition on variables of interest.Results:USA exhibited smaller Ap En values than SSA in the AP signals while no significant differences were observed in the ML Co P signals.Generally,the negative feedback conditions were associated with significantly greater RMS values than the positive feedback conditions.Conclusion:USA exhibit unique postural strategies compared to SSA.These unique strategies seemingly exhibit a direction-specific attribute and may be associated with divergent motor control strategies.

AUV Modeling and Motion Control Strategy Design

To provide a suitable model for AUV simulation and control purposes, a general nonlinear dynamic model including a novel thruster hydrodynamics model was derived. Based on the modeling method, the "AUV-XX" simulation platform was established to carry out fundamental tests on its motion characteristics, stability, and controllability. A motion control strategy consisting of both position and speed control in a horizontal plane was designed for different task assignments of underwater vehicles. Combined control of heave and pitch was adopted to compensate for the reduction of vertical tunnel thrusters when the vehicle is moving at a high speed. An improved S-surface controller based on the capacitor plate model was developed with flexible gain selections made possible by different forms of restricting the error and changing the rate of the error. Simulation results show that the derived general mathematical model together with simulation platform can provide a test bed for fundamental tests of motion control. Additionally, the capacitor plate model S-surface control shows a good performance in guiding the vehicle to achieve the desired position and speed with sufficient accuracy.

Control strategy for multi-pump emulsion power station in coal mine face

Shearer and hydraulic support are matching equipments. To increase the operating speed of the shearer, the following speed of hydraulic support must be increased. This means increasing the volume of flow from emulsion power station. Analyzing the operating characteristics of hydraulic supports, the number of simultaneously operating supports is obtained by means of pressure parameter and time history at a certain time, which is a theory base for development of control system to multi-pump emulsion power station.

Operation control strategy of series-parallel hydraulic hybrid vehicle

A series-parallel hydraulic hybrid system applied to public buses is put torwaro, ano parameters of key components are analyzed and determined. Energy management strategy based on logic thresh- old is designed which is aimed at efficient operation of the overall system considering the operational characteristic of the components and taking the curves of engine, hydraulic pump/motor and hydrau- lic pump as the main design basis; regenerative control strategy which makes regenerative brake sys- tem and frictional brake system work harmoniously is designed to raise recovery rate of regenerative brake energy. System dynamic modeling and simulation results show that the energy control strategy designed here is able to adapt system to changes of working condition and switch the operating mode reasonably. The regenerative braking control strategy is effective in raising the utilization of energy and improving fuel economy.

GLOBALLY ASYMPTOTICALLY STABLE FORMATION CONTROL OF THREE AGENTS

This paper considers the formatiomshape control of three agents in the plane. By adding an adaptive perturbation to any agent＇s movement direction, a novel control strategy is proposed. It is shown that the proposed novel control law can not only guarantee the global asymptotical stability of the desired formation shape, but also ensure the collision avoidance of agents between each other. Simulation results are provided to illustrate the effectiveness of the control algorithm.

An Improved Discrete-Time Model for Heterogeneous High-Speed Train Traffic Flow

This paper aims to present a simulation model for heterogeneous high-speed train traffic flow based on an improved discrete-time model（IDTM）.In the proposed simulation model,four train control strategies,including departing strategy,traveling strategy,braking strategy,overtaking strategy,are well defined to optimize train movements.Based on the proposed simulation model,some characteristics of train traffic flow are investigated.Numerical results indicate that the departure time intervals,the station dwell time,the section length,and the ratio of fast trains have different influence on traffic capacity and train average velocity.The results can provide some theoretical support for the strategy making of railway departments.

Study on the Online Mode of Micro-Grid

Smooth switchover of micro-grid from parallel operation mode to island operation mode is a signif icant method to guarantee the continuous power supply to important loads.This paper puts forward an online work mode on the basis of analyzing the features of parallel operation mode and island operation mode.According to the features of online work mode,the paper gives a f ixed and unf ixed DC bus voltage control strategy and builds the simulation model of unf ixed DC bus voltage control strategy based on Matlab/Simulink.The simulation results show that online work mode based on the unf ixed DC bus voltage control strategy can avoid the unstable problem caused by handoff process between parallel mode and island mode,ensure uninterrupted power supply for important loads,and achieve maximum power tracking of photovoltaic power generation,in addition to reducing the complexity and cost of the system.