Zero-Power Sensing for Underwater Monitoring
Abstract
Today’s sensors are constantly consuming power, that becomes even more when raw data from transducers are processed to extract information. Moreover, much processing is done also when there is no application-relevant information in the processed data. This constant power consumption limits smart sensors’ lifetimes when, as in many real-world applications, they are supplied by batteries. In fact, in the vast majority of application scenarios today sensor devices’ lifetime is only few weeks or months when operating from state-of-the-art batteries. This limit has also slowed the development of large-scale sensor networks, especially due to the need to redeploy power-depleted smart sensors that affect both cost and time to deploy. In many application scenarios where it is impossible re-charge or change the battery, i.e. in underwater environment monitoring, smart sensors usage is limited, even if they could have huge impact. A traditionally effective way to reduce power consumption is to reduce the activity of the sensor device periodically (duty-cycling), however this technique increases detection latency and/or the probability of missing detections. This is a dangerous tradeoff in continuous monitoring applications, where the events are rare but important. A new promising approach is to move toward a new zero-power sensing paradigm where environmental energy, possibly the same energy produced by the physical measurable we want to track, is used to power the sensor and replenish its energy storage. Zero-power sensing targets energy neutrality which enables always-on perpetual monitory and detection of important events. To achieve this ambitious goal, sensors need on one hand to reduce the power consumption and increase the intelligence capabilities to detect events, on the other hand, they must embed a subsystem able to extract and store energy from the monitored environment. The proposed research aims to enhance the current limitations as well as hardware-software co-design methods for this new promising zero power sensing devices in underwater application scenario. Specifically, the project aims to study and develop the basis for zero-power smart underwater sound sensing by exploring the trade-off between power consumption and smart capabilities in underwater monitoring and by exploiting, microbial fuel cell energy sources, energy harvesting and ultra-low power design. The following challenges will be addressed: Investigate and developing techniques and methods to reduce the power consumption of the sensors’ systems decreasing at the same time the response time of the detection, aiming to achieve always-on behaviour (i.e.eliminating the power-responsiveness trade-off typical of traditional duty-cycling). Proposing novel low power mixed analogue-digital signal processing to detect specific patterns on the audio data with micro-watt power level. A multi-stage architecture will be studied and proposed, including uW-level ultra-low power detectors for partial pre-processing (feature extraction pre-classification) and for triggering more computational intensive processing. Exploiting and optimize novel energy harvesting techniques and technologies such as microbial fuel cells to generate power and recharge batteries. This will be coupled with dedicated power management technique to reduce both the power consumption and link it tightly with energy availability. The combination of energy harvesting and always-on detector will be exploited to achieve always-on zero power sensors for next generation of long-term sensors for IoT and intelligent devices. A complete hardware and software prototype smart sensor system, which includes energy harvesting will be developed to demonstrate the benefits of proposed approach and the capability to achieve perpetual self-sustainability on the challenging scenario of underwater acoustic monitoring.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 23, 2019
- Source ID
- N629091912018
Entities
People
- Michele Magno
Organizations
- Office of Naval Research
- United States Navy