Initial Development of Ground Robot-based Launching Device for Volcano Lake pH and Temperature Measurement

Sampling or monitoring crater lakes is a meaningful way to determine volcanic emissions composition. However, close in situ monitoring exposes volcanologists to volcanic chemicals and eruption danger. A robotic remote monitoring system significantly reduces volcanologists’ risk during eruptive phenomena. But, ground robots generally still have difficulties performing crater lake monitoring; it is beyond its immediate vicinity.A capsule launching device from a mobile robot allows for obtaining information on the crater lake conditions. Thus, this paper proposes using a tethered-capsule launching robot for volcano lake monitoring. This capsule contains pH and temperature sensors, as suggested by the Philippine Institute of Volcanology and Seismology (PHIVOLCS). It is also equipped with a wireless transmission module. A unique control technique for the launching and retrieval mechanism of the capsule is also presented. The launching and retrieval mechanism is tested by its ability to launch the capsule by 3 meters and its capability to retrieve it. Testing the pH sensor in three different pH solutions yielded an average error of 1.23 percent. On the other hand, the average difference of the readings from the thermocouple and the laboratory thermometer was 1.03 percent.