Wireless sensor network-based real-time monitoring system for large ship airbag launching: design and field validation

Traditional monitoring solutions for airbag launching of large ships rely on mechanical pressure gauges with limited spatial coverage, slow response times (from several hundred milliseconds to a few seconds), and an inability to monitor dynamically changing attitude parameters during the launching procedure. This paper introduces a WSN-based real-time monitoring solution that combines IMUs and pressure sensors installed at strategic positions on the ship hull and airbags. The solution uses the hierarchical Zigbee mesh with edge computing nodes and the TDMA protocol to deliver real-time, high-speed communication with low end-to-end latency, even under challenging shipyard conditions. The Kalman filter fuses multi-sensor data to provide comprehensive monitoring of pitch, roll, heave displacement, velocity, and acceleration. In-field validation tests have been performed on cargo ships with 1500-2000 DWT capacities during the actual launching process at cooperating shipyards. The system achieves a sampling rate of 100 Hz for inertial data and 50 Hz for pressure data, end-to-end latency under 60 ms (95%), and measurement accuracy of ±0.3° for attitude angles and ±1.5% full scale for pressure measurement. Comparative analysis showed that the proposed system outperforms traditional mechanical gauges with a 75% reduction in spatial blind spots (60%→15% hull coverage), 20–100× faster temporal resolution (50–100 Hz vs. 1–5 Hz), and an 85% reduction in installation time (3.0 h vs. 19.5 h).