Development of Firefighter Walking Condition Monitoring System for Floor Collapse Detection

Firefighters are required to work in hazardous fire scenes. They work in collapsed buildings and smoke-filled areas. Firefighters face a considerable risk of injury because of this environment. In particular, a floor collapse is a matter of life and death for firefighters. Therefore, a supplemental safety device can monitor such conditions and lead to improved safety of firefighters. This paper proposes a firefighter walking condition monitoring system to detect floor collapse. The system attaches pressure sensors to the soles of the firefighter’s shoes. Dangerous walking conditions are detected using pressure values measured from the foot pressure sensors. Our research confirms that the voltage of the foot pressure sensor shows cyclicity during the stair-climbing condition. The voltage of the pressure sensor increases once during the floor-collapse condition, then rapidly decreases. After that, it increases again. It is surmised that the firefighter’s foot cannot contact the ground during a floor-collapse condition. The time variation of voltage is trained and predicted using an LSTM-based neural network. The MAE between the measured and predicted values is calculated. The MAE ranged from 0.30 to 0.55 during stair climbing, while it ranged from 0.67 to 1.50 during the floor-collapse condition. For all subjects, the MAE in the floor-collapse condition is at least 1.56 times larger than that in the stair-climbing condition. As a result, this difference can be used to reliably detect dangerous conditions and alert operators and firefighters.