The basic connotation, core problem and key technology of smart mine

(2) Deep mining of mine data. The original perception data reflects the characteristics of large quantity and low value density, so it is necessary to obtain the judgment of equipment and environment status, the monitoring of abnormal events and the early warning of potential dangers through data analysis and mining. There are many types of mine data [11], such as data reflecting the working status of various equipment, environmental parameters such as temperature, gas concentration and pressure, data reflecting the stress of working face support and the state of coal and rock formations, data reflecting the geographical location of workers and other information. Therefore, the deep mining of mine data must have the ability to mine multi-source data. In addition, the deep mining of mine data should pay special attention to the mining of the relationship between different data.

(3) Mine safety production and management decision support. On the basis of condition judgment, abnormal monitoring and danger early warning, reasonable decisions must be made automatically in combination with mine professional knowledge to realize the adjustment and control of personnel, equipment and environment, so as to ensure the efficiency and safety of production.

3. Key technologies of smart mine

Corresponding to the three core issues of smart mine, the key technologies of smart mine include coal mine Internet of things technology, coal mine big data technology and coal mine intelligent decision support technology.

(1) Coal mine Internet of Things technology. Coal mine Internet of Things technology mainly solves the problem of mine state depth perception, and the core is to obtain more comprehensive data and provide a source for the generation of "wisdom". The sources of mine data are complex, including geology, mining, surveying and mapping, production, machinery and equipment, personnel, finance, etc. The data types include images, graphics, text, tables, etc. [12], and the data changes dynamically in the process of mining. On the basis of expanding network, storage and other facilities, the Internet of Things in coal mines should use intelligent sensors, intelligent cameras, RFID readers, three-dimensional laser scanners [13] and other devices to further broaden the orientation of data acquisition. With the help of coal mine Internet of Things technology, the depth and dynamic perception of all aspects of the state of the mine can be realized, and finally the mass data can be gathered.

(2) Coal mine big data technology. To rise from data to "wisdom", it is necessary to rely on coal mine big data technology, which is mainly used to predict the change of geological environment, detect the abnormal working state of equipment and predict the possible dangerous events in the environment [14-16]. The coal mine big data technology should focus on the comprehensiveness of the analyzed data, and based on this requirement, design an analysis platform that can accommodate both structured and unstructured data, and combine sensor data, monitoring video stream, audio stream and artificially generated data to participate in the big data analysis platform [5,17]. Different big data analysis applications can share computing resources in the same cluster but are logically isolated from each other, ensuring the normal running of heterogeneous services. Big data technology can be used to analyze the change trend of mine geological environment, detect the abnormal state of production equipment, predict the occurrence of dangerous events in the environment, etc., which is conducive to more scientific production safety management [18].

(3) Coal mine intelligent decision support technology. After capturing the changing trend of the environment, the abnormal state of equipment and the occurrence of dangerous events, the smart mine must automatically and quickly handle and respond, such as the automatic alarm of the dangerous area of coal and gas outburst, the automatic fault diagnosis of equipment, lines and ventilation system, and the automatic generation and dynamic update of emergency plans and rescue plans. These need to rely on coal mine intelligent decision support technology. The technology specifically includes three aspects: (1) With the experience of coal mine experts, various expert knowledge bases such as mine safety, production, washing, equipment maintenance, operation and management are built [19] to form an automatic diagnosis and response system for coal mine to ensure the reliability of smart mine decision-making; (2) Through virtual reality and augmented reality technology, the excavation process, gas extraction process, emergency rescue and personnel evacuation are simulated, so as to accumulate new experience and constantly expand the knowledge base; (3) By identifying the ontology of the coal mine field and extracting the relationship between the ontology [20], the knowledge map of the coal mine field is constructed, which is conducive to the construction of a more perfect expert system and provides strong support for coal mine safety production and management.