| With the rapid development of urbanization,the negative influence of traffic jam on the social sustainable development is becoming more prominent.There exist great problems of energy consumption and pollution emission in the existing urban transportation network.Among them,the number of express delivery and logistics transportation demand is a multiple growth,as well as the ground vehicle,train number,freight volume continues to increase,is an important reason for the worsening of traffic congestion.The permanent magnet suspension tube rail logistics system(hereinafter referred to as "Maglev tube rail")combines the permanent magnet suspension technology with the urban underground tube rail logistics transportation system.While transferring most of the logistics transportation to the underground,it forms a three-dimensional logistics transportation network,which can effectively reduce the urban surface logistics transport vehicles,relieve traffic congestion and reduce the accident rate.Secondly,maglev tube rail logistics transportation system adopts permanent magnet suspension,which is more energy saving and environmental protection compared with traditional wheelrail technology and electromagnetic levitation technology,and the operation and maintenance cost is lower.The established permanent magnet rail transit infrastructure cannot be built repeatedly.How to further improve the logistics and transportation efficiency on the basis of not adding lines has become one of the core issues in the future development of maglev tube rail logistics and transportation system.In this paper,based on the permanent magnet suspension underground tube rail logistics transportation system,flexible and dynamic marshalling method is adopted,and wireless communication is used to make multiple trains form a whole in control,breaking the existing train protection concept,and further reducing the distance between train tracking and improving the logistics transportation efficiency on the basis of moving block.According to the characteristics of virtual marshalling of trains,The optimization control method of virtual marshalling of maglev tube rail train is studied.The main work of this paper is summarized as follows:(1)According to the operating environment characteristics of maglev tube rail train,dynamic analysis of permanent magnet suspension tube rail train was carried out from the aspects of tube and rail resistance,running reluctance and additional resistance,and the dynamic model of permanent magnet suspension tube rail train was established,providing a reliable mathematical model for virtual coupling of maglev tube rail train.(2)This paper introduces the principle and key technologies of virtual coupling,improves the train control system based on CBTC according to the requirements of virtual coupling of trains,and expounds the control process of virtual coupling of trains.Finally,according to the train safety braking model,the braking scene of virtual coupling train was analyzed,and the safe distance of virtual coupling train was determined,which laid the foundation for virtual coupling train control.(3)Centering on the virtual coupling operation control of permanent magnet suspension tube rail train,according to the operation characteristics of virtual coupling train and the dynamic model of permanent magnet suspension tube rail,an MPC-PID cascade structure control method was proposed based on the uncertainty,nonlinear and parallel characteristics of the virtual coupling speed control process of multiple trains,combined with the advantages of PID and MPC.The train speed of virtual coupling of the permanent magnet suspension tube rail was optimized.(4)The virtual coupling control simulation of the permanent magnet suspension tube rail train was carried out.The simulation platform was built in Matlab/Simulink environment,and the virtual coupling optimization control of permanent magnet suspension tube rail train was carried out.The detailed analysis was made from the dynamic coupling and adaptive cruise stage,and the speed error interference distance error interference was set in the adaptive cruise stage.Further simulate the possible situation in the actual operation process.The experimental results show that,compared with PID and MPC control,the MPC-PID control algorithm has high speed tracking precision,good safety performance and strong stability performance.In this paper,a dynamic model is established according to the special operating environment of maglev tube rail trains.According to the characteristics of virtual marshalling operation,an MPC-PID virtual marshalling optimization control method is proposed.Through simulation,the accuracy of the model and the effectiveness of the control method are verified,and it has faster response speed and stronger robustness.The research content of this paper has certain reference significance for improving the transportation efficiency of permanent magnet suspension tube rail logistics transportation system and promoting the academic research of virtual marshalling. |
