Research And Implementation Of Long-distance Transmission Monitoring System For Coal Face Based On CAN Bus

In order to improve the production efficiency of coal mine and_reduce the coal mine labor accident, the monitoring system for coal mine face integration is absolutely necessary. A new type of industrial control based on CAN bus has perfect performance at reliability and real-timing, which is used widely in control field for these years.In this paper, the packet structure and working principle of CAN bus were introduced, and the composition of mine face equipment field were analyzed. Intelligent monitoring system based on STM32F103was designed, which is according to the requirements of mine face equipment and spot environment. The circuits were designed in this papers which are about main control, peripherals and other branch node, improvement of the CAN communication transmission, power supply module and communication..This paper selected the bus network topology structure, the priority structure of system was designed by using three different priorities and interrupt responding mechanism, which can distribute the corresponding ID number to lower computer, the multi-node signal transmission were tested. Thesis selected right transmission line for interference conditions of the underground, the CAN bus’s real-time communication rate was tested, the study of the relationship between transmission rate and the transmission distance, which can be the basis for the selection.In order to achieve the functions of underground work face equipment’s monitoring and control and protection, the affecting factors in CAN bus transmission distance were analyzed, and the optimization method for the aspects of bus’s bit timing, termination resistors and network topology was raised. Three analog nodes were used in this paper,2000meters was took as the communication distance, simulation testing about the sign of belt conveyor’s speed, coal face temperature, device operating voltage and control testing about the machine button were accomplished by using simulation verification with some of possible problems in the underground.The experimental results indicates that the system in the aspects of signal acquisition and real-time display and control meet the design requirements. System has a better reliability, when have a long-distance transmission, the signal attenuation distortion is in the controllable range.