2019 Volume 55 Issue 11 Pages 700-708
Investigation of active volcanoes by robots is required to grasp their situation. Considering that volcanic environments are rough terrain, tracked robots are suitable for the investigation. When a tracked robot travels on a volcanic environment, it must climb over obstacles. The obstacles on a volcanic environment can be roughly divided into “fixed obstacles” which can be moved by a robot and “unfixed obstacles” which cannot be moved by a robot. Although a tracked robot climbing over unfixed obstacles such as unstable rocks has risks of sliding-down and tipping-over, there is little research about climbing over unfixed obstacles. On the other hand, grousers on track belts are effective for climbing on fixed obstacles, such as steps or stairs. However, it is unclear whether the grousers are also effective for climbing over unfixed obstacles or not. Therefore, the research purpose is to reveal the effect of grousers for climbing over unfixed obstacles. In this study, the climbing experiment using a cylindrical obstacle and grousers with several conditions of height and gap was conducted. As a result, it was found that grousers also affect to improve the climbing performance for unfixed obstacles. Especially, higher grouser and grouser with a gap which is more than the size the obstacle just fits indicates better performance. Also, the sliding-down condition based on statics was derived to predict the climbing performance of tracked robots. Comparing the condition and the experimental results, it is reasonable for low-height grousers. According to the above research, it becomes clear that the effect of grousers on climbing performance for unfixed obstacles on a two-dimensional plane.
