Volcano Robots

To forecast debris flow in case of a volcanic eruption, our research group made field experiments of robotic technologies in Unzen-Fugen-dake, Nov. 2016. The first experiment was a soil-sampling. The UAV and soil-sampling device returned less than 100g soil. The second experiment was a simple permeability survey with a UAV and a suspended device. It cannot act an actual permeability measurement, but a tendency of permeability can be observed by popping a water balloon. The last experiment was to retracted UGV by UAV’s capturing net. All experiments were conducted in the construction area of Unzen-Fugen-dake, and the sampling device worked in an actual restricted area.

 

In 2013, we succeeded in an initial experiment of robotic observation in volcanic areas for a UGV deployed by a UGV on Mt. Asama. However, the system could not bring the UGV back to the base, because it did not include the function to capture the UGV. Therefore, in this research, we developed a capturing net for retracting a small-sized UGV suspended by UAV. In this videoclip, we introduce a basic experiment for deploying and retracting the UGV with a capturing net hung by a UAV.

 

When an active volcano erupts, a restricted area is imposed around the crater of the volcano for safety. On the other hand, it is important to observe inside of the restricted area. Particularly, sampling and analyzing of volcanic products inside the restricted area is very important for a forecast of volcanic activity and disasters. In our past research, we have been developing a roller type sampling device to obtain small volcanic materials, and carried out indoor experiments and outdoor field tests. Through the experiments, we found that some issues were uncovered. Therefore, in this research, we developed a new sampling devices to solve them. In this video clip, we introduce our new sampling devices, and report outdoor field tests using the devices.

 

In this research, we aim at developing observation technologies of debris flow after volcano eruption using multiple units of multi-rotor MUAVs (Micro Unmanned Aerial Vehicles). On Dec.8-9, 2014, verification tests of volcanic observation were conducted in Sakurajima-Island. In one of the test missions was to observe the active volcano crater. Our MUAV flew to the Showa crater (4km away from the departure point) based on the pre-determined path and returned within 20 minutes. In addition, 3D terrain map was generated by many 2D high-resolution photos based on Structure From Motion (SFM) technique. Smart3Dcapture, commercially available software, was used for the purpose. This video clip includes the above topics and soil-sampling experiment using multi-rotor UAV.

 

Our research group have been developing a roller type sample-return device, which was hanging down from a multi-rotor UAV, and carried out indoor experiments and outdoor field tests. Through the experiments, we found that some issues were uncovered. Therefore, in this research, we developed a new sampling device to solve them. In this video clip, we introduce our recent developed devices, and report outdoor experiments in Mt. Asama.

 

Observation of an active volcano is very important to determine a strategy for estimating its eruptive activity and providing residents with an evacuation warning. Therefore, we have been conducting field tests of robotic observations in a volcanic area using a multi-rotor UAV (unmanned aerial vehicle) and a small ground robot. In this videoclip, we introduce our recent field test of cooperative motion between UAV and small UGV in Sept, 2014, on Mt. Asama. It is almost the same as the demonstration in Sept. 2013, shown the below. It used tether landing to improve its safety, and completed automatic delivering of the small ground robot. The ground robot was tele-operated 3km far away from the robot.

 

When an active volcano erupts, it is important to observe in the area for forecasting debris flood and/or a pyroclastic flow for inhabitants. However, typically, a restricted area is set, such as within a few kilometers radius of the crater. Therefore, we proposed an observation system based on a tele-operated mobile robot via radio communication in active volcanoes. To evaluate the system, we conducted some field tests via 3G communication in Mt. Asama and Mt. Mihara etc. During the experiments, we faced some critical situations that the robot stopped all motion because of weakness of communication signal of 3G. To solve the problem, in this research, we developed a hybrid connection system with multi-robots that is composed of two radio communication lines. In this movieclip, we explain how the system works, introduce our new robots equipped with the system, and report some operation tests on them.

 

In this research, we aim at developing a mobile robot for volcano exploration using a mechanism of roll downhill. This is a mechanical challenge to save energy of locomotion on steep slopes, such as volcano fields. Some steering results are introduced in this videoclip.

 

We developed an improved version of TrackWalker, called TrackWalker-II, that had low center of gravity, and longer tracks. To validate the mechanism, we conducted outdoor experiments in Mt. Mihara in Nov. 2011. In the field experiment, the robot traversed abot 460m on a climbing route of Mt. Mihara (angle:15-25 deg, difference of elevation:85m) and climbed weak and steep slope (32 deg) on Ura-Sabaku.

 

A performance of track mechanism is also much better than wheeled mechanism on loose soil, typically. However, it sometimes slips while traversing slopes comprising loose soil. To realize high mobility on weak soil, we developed a new locomotion mechanism, referred to as surface-contact-type locomotion, called BladeWalker. However, it has the disadvantage of low mobility on irregular terrain. To solve the problem of the above trade-off, we developed the leg-track hybrid locomotion mechanism by fusing the two locomotion mechanisms. It consists of three track modules. It mounts six actuators: three motors for standard tracked locomotion, two motors for sub-tracks' motion to change mounting angles, and one motor for simple legged motion. To validate the mechanism, we conducted outdoor experiments in Mt. Asama.