Study Of Reliable Underground Data Transmission Technique Based On CAN Bus

Coal industry is one of the core industries in China's economic development period. Security issue has been the key and difficulty during the production. The main reason leading to the mining accident is the impeded communication restricted by environment condition. This research project is designed to research and solve the underground communication。The research and analysis are based on the national and industrial standard as well as the specific underground condition. First and foremost, the analysis regarding the comparison of five widely used Fieldbus Technology has been conducted. Due to the special requirements for the communication distance, speed, reliability, and real-time performance, this project decides to adopt CAN bus as the protocol of communication system technology in the underground condition. The research also includes the features of CAN Bus and related communication techniques, and the design of CAN Bus whose hardware ports are SJA1000 and PCA82C250.Special functions of underground communication devices should be also taken into consideration. These devices should be provided with blast resistance, anti-interference, power supply safety, shock resistance, and anti-alternating hot and humid. This article proposed measures that could raise the performance of communication based on the requirement mentioned above.Underground surveillance system includes many sub-surveillance system, gas drainage system, belt comprehensive protection system, and personnel location system, which are all critical. This article also analyzed the significant importance of broadcast system and developed transforming system which could transform verbal command into speech broadcast by combining the current forma. The supervisor computer used software equipment by adopting VB programming language, while the senior machine realized the communication between master and slave device by integrating P89VE1RD2FN SCM and XF-S4240A speech chip. Electrical equipment should be in accordance with related national criteria because of the prone to explosion environment. Through the analysis of transportation and anti-explosion parameters, the examination meets the national standard, and will provide qualified, secure, and reliable underground communication.