Search

Mechanization,automation and informatization of coal mining are inevilable courses of safe and effective production in coal mine and the technology of machine vision is an important part of automation,informatization,digitization and visualization of mine production.The paper introduced the concept and characteristics of the technology of machine vision,discussed pratical significance of applying machine vision in mine,and indicated its application prospect in mine industry.Finally,the paper analyzed some problems which must be solvel when the technology of machine vision is applied in mine.

In view of problem of low location precision in fault location method of underground power cable based on traditional wavelet transform caused by asymmetry of wavelet function, the paper proposed a fault location method of underground power cable based on GHM multi-wavelet. It analyzed principle of multi-wavelet theory, and introduced application of the GHM multi-wavelet in fault location of underground power cable. The simulation result shows that singular points of each scale cannot occur migration after signal of fault current of power cable is transformed by the GHM multi-wavelet, which improves precision of fault location.

The paper proposed coal mine communication technology system which was consisted of mine wired dispatching communication system, mine mobile communication system, mine broadcast communication system and mine rescue communication system. It proposed that mine dispatching communication system should use mine wired dispatching communication system. It proposed that all mine mobile communication system should use communication technologies such as WiFi, 3G and 4G. It proposed that mine broadcast communication system can use either remote powered broadcast technology of mine wired dispatching communication system, or IP communication technology based on Ethernet and passive optical network. It proposed that mine rescue communication system should use wireless multimedia communication technology, and should use communication technologies such as WiFi and MESH. It proposed that mine mobile communication system should meet the demand for mobile phone off network, base station off network, access of coal mine wired broadband transmission platform. It pointed out that WiFi is superior to WCDMA, CDMA2000 and TD-SCDMA for communication of mobile phone off network, access of coal mine wired broadband transmission platform, wireless ad hoc networks, mine-used wireless camera, communication of base station off network, multifunction mine mobile communication system and mine wireless broadband transmission. It proposed that WiFi should be used for multifunction mine mobile communication system and mine wireless broadband transmission.

The paper introduced the basic theory and method of triangular fuzzy number,and established an evaluation indexes system of safety production comprehensive quality of miner based on triangular fuzzy number.By appling the evaluation indexes system to evaluate safety production comprehensive quality of miner quantitatively and comprehensively,the relative weights of various factors of evaluation indexes of safety production comprehensive quality of miner were known as W′_1>W′_4>W′_7>W′_6>W′_KG-*25>W′_2>W′_3,namely that the security responsibility and correcting skills of miners were the most important indexes.The method overcomes the limitation of the method named analytic hierarchy process,and accords with fuzziness of human knowledge, which can reduce personal subjective unilateralism and enhance believability of weight of evaluation indexes.

The paper introduced principle of electrical explosion proof and expounded developing situation of intrinsically safe explosion proof mode form the views of theoretical research and product development at home and abroad.It emphatically discussed problems existed in power supply system for mine safety monitoring at home at present,namely adaptability of the system's input,intelligence of the system,optimum design of standby power supply,anti-interference ability of the system,and intrinsically safe power supply with high capacity.It introduced a novel power supply system for mine safety monitoring,which has good anti-interference performance and functions of intelligent monitoring of the system's running parameters,early warning,and fault diagnosis.

In view of the problem that wireless sensor network ca't make remote transmission because of complex underground situation,the paper proposed a design scheme of mine environmental detection system based on ZigBee wireless sensor network and data radio station.It gave general structure of the system,introduced design of sensor node and gateway node which taking CC2430 as core,and expounded implementation of networking scheme of ZigBee wireless sensor tree network.The test result showed that the system uses communication scheme combing with ZigBee wireless sensor network and data radio station is feasible,which solves problems about low power,remote transmission and high reliability,and networking rule of node numbering makes topology of network has pertinence,which improves accurate position function of node and reduces risk of underground operation.

In view of problems that network topology of underground low-voltage power line is complex and multi-path transmission model is difficult to suit channel modeling of underground low-voltage power line, the paper made a test for channel transmission characteristics of underground low-voltage power line. It indicated that attenuation of underground signal increases with increasing of transmission distance and changes with changing of frequency, and has certain selective fading. It took selective fading as resonant frequency point and used model of series resonant circuit to make modeling simulation for channel attenuation characteristics of underground low-voltage power line, and the simulation result shows that the model of series resonant circuit can well reflect channel transmission characteristics of underground low-voltage power line.

For problem of duplication of network deployment of common WiFi communication system and personnel positioning system which both adopt independent network deployment, the paper proposed a design scheme of integrated mine-used wireless communication and personnel positioning system combining WiFi with RFID. The system realizes functions of wireless communication and personnel positioning through integrated base station, achieves integrated transmission of voice, data and image. The practical application results show that the integrated base station can complete mobile communication and card reading function which reduces investment, and the system is easy to maintain and manage.

For status that most coal mine safety monitoring and control systems adopt fixed and wired sensor network which has blind spots, the paper proposed a design scheme of mine environmental data acquisition equipment based on wireless ad hoc networks, and introduced design of low-power wireless ad hoc networks in details. The equipment takes ATmega16L signle-chip microcomputer as master chip, achieves wireless transceiver by RF transceiver chip NRF24L01, and uses planar network topology and on-demand routing mode. It realizes collection of mine environmental data and early warning, reduces monitoring blind spots, and has higher security and reliability.

The paper proposed a design scheme of selective leakage protection circuit based on method of amplitude discrimination and phase discrimination for electrical control equipments of fully mechanized devices of coal mine underground.The selective leakage protection circuit applied the principle that the phase of zero-sequence current in fault line is in contrast to the one in non-fault line and the phase of zero-sequence current delays the phase of zero-sequence voltage in fault line.It realized function of selective leakage protection for electrical control equipments of fully mechanized devices of coal mine underground through comparison of phases of zero-sequence current and zero-sequence voltage as well as their amplitudes and the setted amplitude.The practice showed that the circuit has strong adaption ability,flexible application,and good reliability.