SearcharxivSearch

arXiv subjects

Maarten Weyn

Publications and source records attributed to Maarten Weyn.

7 recordsLinked to original sources

Managing Task Execution for Unknown Workloads in Batteryless IoT: A Hardware-Agnostic Evaluation

In recent years, the Internet of Things (IoT) paradigm has been shifting toward batteryless, energy-harvesting architectures. Sustaining reliable operation in these systems requires intelligent management of highly volatile stored energy. As edge applications grow in complexity, traditional energy-aware schedulers struggle with unpredictable workloads due to their reliance on static execution thresholds or pre-measured, hardware-specific task profiles. To overcome this, we propose two novel, hardware-agnostic dynamic scheduling strategies treating applications as a "black box," requiring no prior energy information: a model-free Reinforcement Learning (RL) agent and an on-the-fly Approximated Prediction (AP) method. We evaluate these methods against an adaptive task rate approach (AsTAR) and optimized static thresholds using a custom-built, physically accurate simulation framework driven by real-world solar data and dynamic LoRa transmission profiles. Rather than claiming universal superiority, our analysis exposes the distinct operational trade-offs of each method: the AP approach delivers lightweight, near-oracle task throughput; the RL agent provides tunable survival-execution balancing; and AsTAR excels at execution pacing across long energy gaps. Finally, we demonstrate that while these advanced strategies provide critical resilience for severely constrained systems with small capacitors, devices with larger energy buffers can efficiently rely on simpler, less computationally expensive static policies.

cs.LG

Feasibility of Energy Neutral Wildlife Tracking using Multi-Source Energy Harvesting

Long-term wildlife tracking is crucial for biodiversity monitoring, but energy limitations pose challenges, especially for animal tags, where replacing batteries is impractical and stressful for the animal due to the need to locate, possibly sedate, and handle it. Energy harvesting offers a sustainable alternative, yet most existing systems rely on a single energy source and infrastructure-limited communication technologies. This paper presents an energy-neutral system that combines solar and kinetic energy harvesting to enable the tracking and monitoring of wild animals. Harvesting from multiple sources increases the total available energy. Uniquely, the kinetic harvester also serves as a motion proxy by sampling harvested current, enabling activity monitoring without dedicated sensors. Our approach also ensures compatibility with existing cellular infrastructure, using Narrowband Internet of Things (NB-IoT). We present a simulation framework that models energy harvesting, storage, and consumption at the component level. An energy-aware scheduler coordinates task execution based on real-time energy availability. We evaluate performance under realistically varying conditions, comparing task frequencies and capacitor sizes. Results show that our approach maintains energy-neutral operation while significantly increasing data yield and reliability compared to single-source systems, with the ability to consistently sample GPS location data and kinetic harvesting data every two minutes while transmitting these results over NB-IoT every hour. These findings demonstrate the potential for maintenance-free, environmentally friendly tracking in remote habitats, enabling more effective and scalable wildlife monitoring.

cs.NI

Seismocardiography for Emotion Recognition: A Study on EmoWear with Insights from DEAP

Emotions have a profound impact on our daily lives, influencing our thoughts, behaviors, and interactions, but also our physiological reactions. Recent advances in wearable technology have facilitated studying emotions through cardio-respiratory signals. Accelerometers offer a non-invasive, convenient, and cost-effective method for capturing heart- and pulmonary-induced vibrations on the chest wall, specifically Seismocardiography (SCG) and Accelerometry-Derived Respiration (ADR). Their affordability, wide availability, and ability to provide rich contextual data make accelerometers ideal for everyday use. While accelerometers have been used as part of broader modality fusions for Emotion Recognition (ER), their stand-alone potential via SCG and ADR remains unexplored. Bridging this gap could significantly help the embedding of ER into real-world applications, minimizing the hardware, and increasing contextual integration potentials. To address this gap, we introduce SCG and ADR as novel modalities for ER and evaluate their performance using the EmoWear dataset. First, we replicate the single-trial emotion classification pipeline from the DEAP dataset study, achieving similar results. Then we use our validated pipeline to train models that predict affective valence-arousal states using SCG and compare them against established cardiac signals, Electrocardiography (ECG) and Blood Volume Pulse (BVP). Results show that SCG is a viable modality for ER, achieving similar performance to ECG and BVP. By combining ADR with SCG, we achieved a working ER framework that only requires a single chest-worn accelerometer. These findings pave the way for integrating ER into real-world, enabling seamless affective computing in everyday life.

cs.HC

Experiences with Sub-Arctic Sensor Network Deployment and Feasibility of Geothermal Energy Harvesting

This paper discusses the experiences gained from designing, deploying and maintaining low-power wireless sensor networks in three geothermally active remote locations in Iceland. The purpose of deploying the network was to collect soil temperature data and investigate the impact of global warming on (sub)Arctic climate and subsequent carbon release. Functional networks from three sites with no direct access to power and the internet have been providing researchers with insight into the warming impacts since 2021. The network employs low-power wireless sensor nodes equipped with DASH7 communication protocol, providing real-time data and remote access to sensors and instruments deployed in the field. In addition to discussing the architecture and deployment of the network, we conduct a primary analysis using models and methods to demonstrate the feasibility of harvesting energy from the temperature gradient between geothermally active soil and air.

cs.NI

Low-latency Symbol-Synchronous Communication for Multi-hop Sensor Networks

Wireless sensor networks (WSNs) have received great interest due to their scalability, energy efficiency, and low-cost deployment. By utilizing multi-hop communication, WSNs can cover a wide area using low transmission power without the need for any communication infrastructure. Traditionally, WSNs rely on store-and-forward routing protocols and Time Division Multiple Access (TDMA)-based schedules that avoid interference between different wireless nodes. However, emerging challenging scenarios, such as the industrial Internet of Things (IoT) and robotic swarms, impose strict latency and reliability requirements, which traditional approaches cannot fulfill. In this paper, we propose a novel symbol-synchronous transmission design that provides reliable low-latency communication with a reasonable data rate on classical sub-6GHz RF frequency bands (e.g., the 2.4GHz ISM band). Instead of avoiding overlapping transmissions, the proposed scheme benefits from concurrent transmissions. Using simulation in MATLAB, we prove that the proposed design allows achieving a wire-like delay of 5ms for a 512-bit packet over multiple hops with only a 0.3% latency increase per extra hop and a low bit error rate (BER) of 0.04%. Compared to similar state-of-the-art approaches it can achieve a significantly higher data rate of 100kbps, which is expected to increase further with future improvements of the system.

cs.NI

Experiences with Sub-Arctic Sensor Network Deployment

This paper discusses the experiences gained from designing, deploying, and maintaining low-power Wireless Sensor Networks (WSN) in three geothermally active remote locations in Iceland. The network was deployed for environmental monitoring and real-time data collection to assist in investigating the impact of global warming on the (sub)Arctic climate and the resulting carbon release from the region. Functional networks with more than 50 sensor nodes from three sites with extreme weather conditions and hard-to-access terrain have been collecting data since 2021. The networks employ primary cell-powered wireless sensor nodes equipped with DASH7 Alliance Protocol (D7A) for low-power data transmission and solar-powered D7A-cellular gateways for the backend connection. The WSNs have so far achieved over three years of uptime with minimal maintenance required throughout this period. We present a detailed discussion of different network components, their architecture, and the networks' overall performance and reliability.

eess.SY

InfiniteEn: A Multi-Source Energy Harvesting System with Load Monitoring Module for Batteryless Internet of Things

This paper presents InfiniteEn, a multi-source energy harvesting platform designed for the Internet of Batteryless Things (IoBT). InfiniteEn incorporates an efficient energy combiner to combine energy from different harvesting sources. The energy combiner uses capacitor-to-capacitor energy transfer to combine energy from multiple sources and achieves a nominal efficiency of 88\%. In addition to multiplexing different sources, the energy combiner facilitates the estimation of the harvesting rate and the calibration of the capacity of the energy buffer. The energy storage architecture of InfiniteEn employs an array of storage buffers that can be configured on demand to cope with varying energy harvesting rates and load's energy requirements. To address the challenge of tracking the energy state of batteryless devices with minimum energy overhead, this work introduces the concept of a Load Monitoring Module (LMM). InfiniteEn is a load-agnostic platform, meaning that it does not require any prior knowledge of the energy profile of the load to track its energy states. The LMM assists InfiniteEn in tracking the energy state of the load and dynamically modifying the storage buffers to meet the load's energy requirements. Furthermore, the module can detect and signal any abnormalities in the energy consumption pattern of the load caused by a hardware or software defect. Experiments demonstrate that LMM has a response time of less than 11 ms to energy state changes.

eess.SP