考虑新机场投运的多式联运组织演化博弈——以北京大兴国际机场为例

为迎合市场需求,激发北京市新机场及周边企业运输潜力,发展多式联运并合理调动运输供给资源成为关键。通过建立航空运输企业、公路运输企业及多式联运经营人三方演化博弈模型,对各参与方组建多式联运组织的策略、选择演化路径及合作机制进行研究。各参与方在成本投入与可获得的额外收益之间权衡,决策是否选择组成联运组织。研究过程中设置合作意愿,对多式联运组织各参与方策略选择的演化路径进行仿真分析,并分别改变业务规模系数、运输收益系数及新市场损失系数,就各参与方行为对其策略选择的演化结果进行分析。结果表明:各参与主体初始意愿的变化对多式联运组织的建立和有效运营产生直接影响,即运输企业对合作策略的初始意愿是多式联运组织形成的关键;经营人企业的行为策略选择也将影响航空运输企业和公路运输企业的成本付出与新市场带来的额外收益获得,组织内部因素(例如合理收益分配)有助于促进多式联运组织有效形成;组织业务规模、市场发展状况变化等外部环境因素也对多式联运组织成员的意愿值有所影响,即不同运输企业行为会影响经营人企业的经营态度,也将作用于组织的演化方向及到达均衡状态的演化时间。

西江航道船闸管理的制度分析

以西江航道船闸管理制度体系为研究对象,分析西江航道船闸管理制度存在的顶层制度缺失、联动机制缺失和具体管理制度不完善等问题,从建立西江航道船闸管理顶层制度、建立多层次西江航道船闸管理联动机制、完善西江航道船闸具体管理制度体系等方面阐述相应对策。

Modeling and motion control simulation of tendon based parallel manipulator translation mechanism for sensor based high value waste processing

A novel sorting system based on one degree of freedom (DOF) tendon based parallel manipulator (TBPM) for high value waste processing was presented and designed. In order to control the motion of loads, nonlinear state feed forward control algorithm in the tendon length coordinate was used. Considering the system redundancy and actuation behavior, algorithms of optimal tension distribution and forward kinematics were designed. Then, the simulation experiments of motion control were implemented. The results demonstrate that the proposed TBPM translation system performs robust capacities. It can transfer the loads 1 m away within 1.5 s. With further optimization, the translation duration can be further reduced to be about 1 s and the optimized translation is followed with 43.59 m/s2 maximum acceleration. The translation errors at the aim position remain below 0.4 mm.

The Design of a Motion Control System for a Parallel Robot with Image Positioning

A motion control system for a parallel robot with image positioning was implemented in this paper. The system is composed of a machine vision device, a delta robot and a linear stage, and the concerned hardware, software and working methods were developed completely and verified successfully. During the phase of machine vision, the image of object was captured by camera, and then the process of smoothing filter, threshold algorithm and edge detection, was applied so as to obtain the edges of image. Finally, DV-GHT （Displacement Vector Generalized Hough Transformation） algorithm was used to recognize the center of multiple and arbitrary 2-D shapes objects. After the center of objects was recognized, the objects were delivered to the workspace of a delta robot by a motorized stage. Through the coordinate transformation between the camera and the robot system, the information of center can be converted to control commands for every working motors. Following, the delta robot picks up objects to the specified position sequentially by the trajectory planning and tracking controls. The software of C＋＋/CLI is used to achieve the phase of motion controls and the program of DV-GHT is used to detect and conduct the positions for four different characteristics of the objects simultaneously so as to indicate the delta robot to classify the objects successfully.

Coupling mechanism of mathematical models for sediment transport based on characteristic theory

This paper aims to explore the coupling mechanism between flow movement, sediment transport and riverbed evolution in currently widely used mathematical models for sediment transport. Based on characteristic theory, analytic forms of eigenvalues,eigenvectors and characteristic relationships of total-sediment transport model, bed-load transport model and suspenedload transport model were derived, respectively. The singular perturbation technology was implemented to obtain the asymptotic solutions to different families of eigenvalues. The results indicate that, interactions between motion variables were explicitly coupled in the characteristics of total-sediment transport model and bed-load transport model. Further qualitative and quantitative analysis demonstrates that high sediment transport intensity and significant riverbed change will inevitably affect the property of flow movement. In the process of deposition, sediment-laden flow will move faster when sediment transport intensity becomes stronger. In contrast, the wave of flow will propagate at slower speed as erosion intensity becomes stronger.For most existing suspended-load transport models, however, the characteristics are decoupled as the interactions between motion variables cannot be integrally illustrated in eigenvalues, eigenvectors and characteristic relationship.

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.