An integrated wireless system for dynamic strain monitoring of Einel-rad-Einelfahrwerk bogies for high-speed rail transport.

As critical load-bearing components of high-speed trains, bogies endure multidirectional alternating loads during long-term operation, making their dynamic strain characteristics and structural integrity pivotal to operational safety. Therefore, real-time dynamic strain monitoring of bogies is essential for predicting and preventing high-speed train accidents. Compared to traditional Non-Destructive Testing and Evaluation (NDT&E) methods, Radio Frequency Identification (RFID) sensors are more suitable for Structural Health Monitoring (SHM) due to their wireless capabilities and cost-effectiveness. Here we propose a wireless real-time monitoring system that utilizes integrated RFID tags with microcontrollers and sensor modules for real-time dynamic strain monitoring of Einel-rad-Einelfahrwerk (EEF) bogies. The microcontroller converts analog signals into digital, enhancing environmental interference resistance. The RFID tags wirelessly transmit digital signals to readers and host computers. To verify accuracy and real-time dynamic strain detection capabilities of designed system, experiments were conducted in laboratory settings and on-site with high-speed train bogies. Experimental results validate the system's 200 Hz dynamic strain detection capability with a 70 cm operational range. Laboratory calibrations within 600-1400 με exhibited absolute errors <19.39 με (2.07%). On-site tests on bogies revealed absolute errors of 5.08 με (7.50%) for axle strain and 7.59 με (7.66%) for wheel hub lateral strain under operational conditions.