Development of a Blade-type Crawler Mechanism for a Fast Deployment Task to Observe Eruptions on Mt. Mihara

摘要

Observing a crater during a volcanic eruption is a dangerous task that is still being performed by volcanologists. Because of the risks involved, it is proposed that this observation be performed by robots rather than humans. Unlike rescue robots that operate inside buildings, those that observe craters during volcanic activities are expected to demonstrate rapid movements because the environmental conditions during an eruption can change in a split second. Furthermore, the cost of the robots to be developed should be kept to a minimum, as there is a high chance that they will be damaged or lost. This study proposes a blade-type crawler vehicle with improved performance over rough terrain. The vehicle does not compromise speed nor does it have complex controls, which keeps the cost low. The objective of the study was to observe eruptions on Mt. Mihara on Izu Oshima Island, where there have been threats of eruption in recent years. The proposed vehicle was tested, and its effectiveness was demonstrated through laboratory experiments and a field test on Mt. Mihara. This vehicle was capable of traveling on scoria desert and vulnerable, uneven, and rough terrain, including bushes, on Izu Oshima Island. In addition, the vehicle recorded a maximum velocity of about 10 km/h and climbed over steps with a height of about 135 mm, which is about 270% of the diameter of its wheel. Moreover, it is small, lightweight (2.5 kg), and it can be operated by one person. Through practical experiments, it was verified that the vehicle demonstrated superior performance and speed over rough terrain as compared with other crawler mechanisms. Therefore, it was found that the mechanism was effective for an unmanned probe device, especially in a hypothetical volcanic eruption site on Izu Oshima Island.