R&D Focus

SoPoWake Provides Landslide Surveillance

Video of SoPoWake.

An autonomous landslide surveillance (ALS) system uses soil moisture sensors to monitor the water content in soils and generates alert messages over a wireless network to provide early warnings of possible imminent occurrence of mudslides. Unfortunately, existing combinations of regenerative energy and battery cannot sustain an ALS system throughout an entire year because the regenerative energy subsystem simply cannot produce enough energy during certain periods, e.g., solar energy during rainy seasons, in shade or at night.

Dr. I-Horng Pan, Principal Researcher from ITRI’s Biomedical Technology and Device Research Laboratories.

SoPoWake, a self-sustainable landslide surveillance system.

ITRI’s Soil-Powered Wake-up (SoPoWake) is an improvement to traditional surveillance systems that sense and transmit data at specific periods of time instead of continuously monitoring to save power. Rather than utilizing the “periodic data sensing and transmission” method, SoPoWake applies a self-triggered technology that can greatly improve power efficiency. Compared with other environmental monitoring and warning systems, SoPoWake has a much longer endurance and can last for decades.

SoPoWake solves the energy supply problem of ALS systems by an environmental interrupt mechanism, which wakes up the sensor and communication circuits in an ALS node only when the water content in monitored soils exceeds a certain threshold, and thus completely eliminates the need for an ALS node to periodically wake up, sense, and communicate. As a result, SoPoWake ALS system’s power consumption is close to zero when the water content level is low, and starts to increase after the water content level escalates beyond a threshold, at which point the SoPoWake ALS system draws energy from its battery to operate its sensor and communication circuits. By tightly integrating energy harvesting, environment sensing and circuit wake-up, ITRI’s SoPoWake is the most energy-efficient ALS system designed to monitor water content in soils in the world.

SoPoWake is important because ALS systems can save lives, by providing various early alarms including landslides accompanied by earthquake or mudslides after heavy rainfalls and thus offering a prior warning to evacuate or take other appropriate action. SoPoWake simultaneously captures signals and harvests power using the moisture of the land in which it has been installed.

The application of ITRI’s SoPoWake technology is wide-ranging. It can be used for environment monitoring and positioning because it provides electric energy for autonomous landslide surveillance. It can also act as a backup energy source, because SoPoWake can be equipped to charge a battery in an emergency.