| In recent years,coal mine safety production problems occur frequently,so the prevention of coal mine gas safety accidents should be pay more attention to..The main component of coal mine gas is methane.The existing gas methane safety monitoring systems mostly use the wired connection way,which has significant limitations of measuring distance.As the exploitation of the coal mine,the working surface equipment needs to move forward.The mutual position of the equipment also changes,so the cable monitoring network cannot follow the changes of the mine road in time.All this easily leads to a blind monitoring area.Combined with the existing wired network monitoring system,the wireless communication technology is applied to the methane safety monitoring system,which can help build a more comprehensive information transfer underground methane monitoring system and improve the existing problems in the field of gas monitoring.Based on the methane detection technology and wireless communication technology summary,the catalytic combustion type sensor and the Zig Bee wireless technology solutions are chosen.The design of the system is divided into three parts: sensor node,router and network coordinator.The sensor node uses the catalytic type sensing element and efficient pulse width modulation technique of methane detection.The methane concentration in the environment is converted to analog signal by the sensor and its front-end circuit,and the analog signal is sent to the SCM.The wireless communication circuit reads the output information of the single chip microcomputer and establishes the connection between the Zig Bee wireless transmission mode and the router.The main function of router is expanding transmission routing distance and connecting terminal sensor monitoring node.Network coordinator is responsible for building up the Zig Bee sensor network,setting up the network parameters,and displaying monitoring node concentration.The wireless communication circuit in the system uses the CC2530 wireless chip of TI company,and the node uses the intermittent operation mode to save energy,which meets the needs of safety and practicality.Through the test experiment on the prototype system,the results show that the performance of the system designed in this paper meets the national standards for coal mine safety monitoring system,which can reduce the occurrence of safety accidents in mine actual production. |
