TY - JOUR PY - 2018// TI - A guided vehicle under fire conditions based on a modified ultrasonic obstacle avoidance technology JO - Sensors (Basel) A1 - Li, Sen A1 - Feng, Chunyong A1 - Liang, Xiaoge A1 - Qin, Hengjie A1 - Li, Haihang A1 - Shi, Long SP - s18124366 EP - s18124366 VL - 18 IS - 12 N2 - Low visibility and hot smoke environment under fire conditions can largely hamper the related fire rescue processes. Ultrasound obstacle avoidance technology is then useful for guidance. However, the biggest challenge of adopting ultrasound technology comes from accurate distance measurements under the disturbances of high temperature and soot particle concentration. It is critical to measure the propagation speed under the complicated fire conditions. Therefore, in this study, a baffle calibration method was proposed to improve the accuracy of distance measurement of an obstacle. The method is based on two ultrasound measurement systems, while one is used to calibrate the propagation speed of ultrasound based on the fixed distanced baffle and the other is for the dynamic measurement of obstacle distance based on the calibrated speed. The viability of this method on the guided vehicle was confirmed based on the experiments. From its comparison to those existing methods, such as constant speed and temperature compensation methods, it was known from that the proposed baffle calibration method provides the best prediction. It was obtained that the maximum errors based on the baffle calibration method are 2.75% and 2.62% under the two representative fire scenarios, respectively, which are much lower than those of constant speed (7.81% and 8.4%) and temperature compensation methods (10.4% and 5.12%).
Language: en
LA - en SN - 1424-8220 UR - http://dx.doi.org/10.3390/s18124366 ID - ref1 ER -