Design Of Mine Communication System Based On Data Distribution Service

Smart mining is an important direction for the future development of the coal mine industry.It puts forward higher requirements for the safety and reliability of the mining process.Currently,the real-time performance and reliability of data transmission are limited by many factors,such as the structure of network and the amount of data.Therefore,it is of great theoretical significance and engineering value to research on the real-time communication of coal mines and their internal substations.The paper proposes to use Data Distribution Service(DDS)in the field of mine communication and its internal substations regarding of the problems of complex communication structure and high real-time requirements in the current mine communication.The working principle,communication structure and technical characteristics of DDS are compared with the Manufacturing Message Specification(MMS)to analyze their differences and study the law of delay.The main work of this paper includes the following contents.(1)The paper introduces the research background and its significance,analyzes the development and bottleneck of the smart mine.The research status of communication technology for mine and its internal substation is outlined and the chapter arrangement is introduced.(2)The current status of substation communications which is based on IEC 61850 standard and outlines IEC 61850 standard and three layers of network structure for the substation are presented.The seven types of messages and four kinds of application protocols in the substation are researched,which include MMS,Simple Network Time Protocol,Sample Value,and Generic Substation Event.(3)A new communication technology called DDS is proposed to replace the existing MMS,and five kinds of application protocols are compared.The communication structure of DDS based on a data-centric publish/subscribe model is analyzed,and comparative analysis is carried out with two other Ethernet communication models,such as point-to-point and client/server model.Three characteristics and their applicable occasions are compared.The communication process and steps of the publish/subscribe model are analyzed and clarified.(4)The substation information model based on MMS and DDS is investigated,and the operation information for substation based on the DDS protocol is studied.Service primitives are used as the medium to research the TCP protocol of MMS and the UDP protocol of DDS,and the end-to-end delay of the two protocols is analyzed,and their delay law is summarized and compared.(5)Substation simulation model under the star and ring topology is constructed which is based on OPNET.The data flow inside the substation is modeled,then the delay results of substation which is under the DDS and MMS protocols are obtained.The load and link bandwidth as variables are set,such as 10 Mbps,100 Mbps,and 10 Gbps,to analyze and compare the DDS and MMS delays under different loads and link bandwidths,and verify that DDS has better delay performance than MMS.