Weight difference estimation is crucial in various applications, particularly for identifying items being picked up and put back when people interact with the shelf while shopping in autonomous stores, ensuring precise cost estimation. However, the conventional approach of estimating weight changes requires specialized weight-sensing shelves, which are densely deployed weight scales, incurring intensive sensor consumption and maintenance costs. Prior works explored the vibration-based weight sensing method, but they are limited to the object that can generate vibration through motion. This work demonstrates a system leveraging active vibration sensing for weight difference estimation on shelves at different locations. The main intuition of the system is that the weight placed on the shelf influences the dynamic vibration response of the shelf, thus altering the shelf vibration patterns. Our system achieves a mean absolute error 9.23 grams and mean absolute percentage error 7.9% on the real-store shelf layout.

Precision Swine Farming has the potential to directly benefit swine health and industry profit by automatically monitoring the growth and health of pigs. We introduce the first system to use structural vibration to track animals and the first system for automated characterization of piglet group activities, including nursing, sleeping, and active times. PigSense uses physical knowledge of the structural vibration characteristics caused by pig-activity-induced load changes to recognize different behaviors of the sow and piglets. For our system to survive the harsh environment of the farrowing pen for three months, we designed simple, durable sensors for physical fault tolerance, then installed many of them, pooling their data to achieve algorithmic fault tolerance even when some do stop working. The key focus of this work was to create a robust system that can withstand challenging environments, has limited installation and maintenance requirements, and uses domain knowledge to precisely detect a variety of swine activities in noisy conditions while remaining flexible enough to adapt to future activities and applications. We provided an extensive analysis and evaluation of all-round swine activities and scenarios from our one-year field deployment across two pig farms in Thailand and the USA. To help assess the risk of crushing, farrowing sicknesses, and poor maternal behaviors, PigSense achieves an average of 97.8% and 94% for sow posture and motion monitoring, respectively, and an average of 96% and 71% for ingestion and excretion detection. To help farmers monitor piglet feeding, starvation, and illness, PigSense achieves an average of 87.7%, 89.4%, and 81.9% in predicting different levels of nursing, sleeping, and being active, respectively. In addition, we show that our monitoring of signal energy changes allows the prediction of farrowing in advance, as well as status tracking during the farrowing process and on the occasion of farrowing issues. Furthermore, PigSense also predicts the daily pattern and weight gain in the lactation cycle with 89% accuracy, a metric that can be used to monitor the piglets’ growth progress over the lactation cycle.

Object classification is a vital technology that is widely used to track and identify misplaced and out-of-stock items in shopping centers. While there have been a number of studies utilizing various sensing modalities such as computer vision, RFID, and vibration sensors, these methods are limited in their use due to privacy concerns, scalability, and the inability to identify stationary objects. To overcome these limitations, we propose a novel active vibration-sensing approach for object classification by utilizing music as an excitation source. Different objects can induce different deformations of the surface and further change the surface structural response. Therefore, we leverage vibrations from music on a store shelf and measure the structural responses on the surface when different objects are placed. Our evaluation of a store shelf demonstrates that distinct object characteristics lead to unique vibration responses, enabling accurate classification of 98.6% accuracy in distinguishing five common store objects. This study provides a promising avenue for a reliable, privacy-preserving, and scalable object classification system in various settings beyond shopping centers.

IoT (Internet of Things) devices, such as network-enabled wearables, are carried by increasingly more people throughout daily life. Information from multiple devices can be aggregated to gain insights into a person’s behavior or status. For example, an elderly care facility could monitor patients for falls by combining fitness bracelet data with video of the entire class. For this aggregated data to be useful to each person, we need a multi-modality association of the devices’ physical ID (i.e., location, the user holding it, visual appearance) with a virtual ID (e.g., IP address/available services). Existing approaches for multi-modality association often require intentional interaction or direct line-of-sight to the device, which is infeasible for a large number of users or when the device is obscured by clothing. We present IDIoT , a calibration-free passive sensing approach that fuses motion sensor information with camera footage of an area to estimate the body location of motion sensors carried by a user. We characterize results across three baselines to highlight how different fusing methodology results better than earlier IMU-vision fusion algorithms. From this characterization, we determine IDIoT is more robust to errors such as missing frames or miscalibration that frequently occur in IMU-vision matching systems.

Small unmanned autonomous vehicles (UAVs) swarms are becoming ubiquitous in a number of applications (e.g., surveying, monitoring, and situational awareness). Indoor environments may contain metal equipment that temporarily disrupts radio reception. During these momentary interruptions, a small UAV needs to be able to broadcast a 'heartbeat' to indicate that it is not damaged or lost. Considering alternative messaging modalities, we observe that light-based methods require line-of sight, which is not guaranteed when UAVs are moving through a cluttered environment, while a naive sound-based method is easily drowned out by the UAV's own loud motor and propeller noise.

Cyber-physical systems are used both for sensing the environment around them as well as making changes to that environment (actuation). Interactions between actuators and sensors can create interference or uncertainty, but can also be leveraged to improve the sensing coverage, sensing resolution or capability of a cyber-physical system. The challenge in modifying actuator behavior in a system is to avoid degrading the actuation range or responsiveness. The acceptable range of actuator adaptation can be modelled and tested using physics-based, data-driven, or combination approaches.

Indoor localization systems cannot rely on the same mechanisms, like GPS, that are used for outdoor or large-scale localization. Instead, autonomous or user-carried devices are often localized by measuring the time taken for an emitted signal to reach a known location; this signal can be sound, light, radio waves, or another similar sensed quantity. Autonomous mobile devices already contain motors, which produce sounds as a side effect of their operation, and so can potentially be included in a localization scheme without new hardware. In this paper, we briefly outline the challenges that need to be met for accurate detection and identification of motor-produced signals. We present a method for improving signal resolution for linear chirps that improves cross-correlation based signal detection by up to 2.8X.

In this paper, we present Intercom, a simulator framework that provides separate components to address the interdependent aspects of IoT systems, such as sensing, physical interaction, wireless communication, and computation. We initially evaluate a scalable sensing and communication model, which simulates wireless signal strength measurements with an average error of 6.1dBm.

We describe a step-level indoor localization system which uses the ground vibration induced by human footsteps. Indoor localization is important for various smart building applications, including resources arrangement optimization, patient/customer tracking, etc. Geophones are used to measure the ground vibrations and time difference of arrival (TDoA) for different sensors are used to solve the multilateration localization problem. The advantages of this system include its sparsity and also its stability over time. Lesser dependency on instrument people is another upside of this system. The results of pilot tests show that this system can be successfully used for indoor localization.