Abstract:When monitoring the health status of the axial fans in the tunnel, because of the limitation of computing power, the fault monitoring system cannot judge the fault type locally. The complex transmission environment leads to serious multipath fading of wireless signal transmission. In this case, Long Range Radio(LoRa) spread spectrum chip is used to build a fault monitoring system. Its unique spread spectrum modulation technology enables reliable data transmission in harsh environments. The data transmission rate is low; for this problem, an adaptive transmission mechanism is proposed. When the channel environment is better, the sampling frequency and quantization code bits are increased, and more vibration information details are transmitted to improve the accuracy of fault identification; after the channel environment becomes worse, Reduce the uploaded data to reduce the transmission pressure, and analyze the performance of the fault monitoring system of the adaptive transmission strategy in different channel environments. Finally, through experimental analysis, compared with ordinary 4G transmission, the LoRa fault monitoring system with adaptive transmission strategy can achieve a higher accuracy rate for fault diagnosis of vibration data, and is more suitable for reliable and efficient data transmission in harsh environments such as tunnels. ;