The Safety Monitoring And Warning System Of Rail Vehicles In Collieries Based On WLAN

With the continuous development of economy and society, more and more attention is paid to the security situation in collieries, thus a wide variety of safety monitoring and control systems have been developed to apply to specific application environments. However, the safety monitoring and controlling measures of rail auxiliary vehicles have not yet been improved correspondingly. Therefore, we propose a safety monitoring and warning system in collieries based on WLAN technology and realize a prototype.Firstly, both of the overall function and the structure of the system are designed in detail, based on in-depth usage requirements analysis in the practical application scenarios. The whole system is divided into four different functional blocks, they are namely the vehicle monitoring unit CMU, the winch control unit WCU, the video display unit VDU and the tunnel network communication block. Among them, the CMU is for real-time monitoring of obstacles in the front of carts, the WCU is for automatic brake handle of rail vehicles, the VDU is in charge of real-time displaying of video and working status information, and the tunnel network block completes reliable transmission of data instruction information and video image. Then the communication transmission protocol is designed specifically, including the working principle and the data frame format. At the last, each of the functional modules is designed in detail and then implemented respectively. We complete the construction of the hardware circuit, block building and interfacing, and the upper application development, achieving a prototype of all basic expected functions.Meanwhile, the AP handoff issues which involving the tunnel video communication process is studied specifically. We come up with an AP fast handoff scheme which is suitable for the system. The channel allocation strategy, the handoff mechanism and the authentication mechanism are designed and implemented for the AP handoff scheme. On the basis of this scheme, we further put forward a corresponding improvement strategy and give the concrete analysis in theory.Finally, the system while is designed and developed is tested, including function test and performance test. The results of function test show that the system is able to complete all the basic required functions. The results of performance test show that the performance of the system is able to reach to a certain standard, and it can basically meet the practical application requirement. On the whole, the safety monitoring and warning system of rail vehicles in collieries based on WLAN can play the expected in collieries and thus improve the safety of at least the coal mining industry, and it can also play an important role to promote a further study of the safety monitoring and control system.