In this paper, we describe and validate the EquiMoves system, which aims to support equine veterinarians in assessing lameness and gait performance in horses. The system works by capturing horse motion from up to eight synchronized wireless inertial measurement units. It can be used in various equine gait modes, and analyzes both upper-body and limb movements. The validation against an optical motion capture system is based on a Bland–Altman analysis that illustrates the agreement between the two systems. The sagittal kinematic results (protraction, retraction, and sagittal range of motion) show limits of agreement of degrees and an absolute bias of degrees in the worst case. The coronal kinematic results (adduction, abduction, and coronal range of motion) show limits of agreement of and degrees, and an absolute bias of degrees in the worst case. The worse coronal kinematic results are most likely caused by the optical system setup (depth perception difficulty and suboptimal marker placement). The upper-body symmetry results show no significant bias in the agreement between the two systems; in most cases, the agreement is within ±5 mm. On a trial-level basis, the limits of agreement for withers and sacrum are within ±2 mm, meaning that the system can properly quantify motion asymmetry. Overall, the bias for all symmetry-related results is less than 1 mm, which is important for reproducibility and further comparison to other systems.
Providing an integrated Product-Service System (PSS) supported by Cyber-Physical Systems (CPS), as a smart solution, is increasingly offered by industrial machinery. In this approach, instead of providing products with after-sale services, the value proposition is mostly based on guaranteeing a trustable operation. As a result, capturing and analyzing information from a machine’s condition during its lifespan becomes an essential part of the smart PSS. Enabling this through lifecycle monitoring, sensing devices are at the core of smart PSS. Thus, the optimal configuration of PSS components is a critical step to ensure the efficiency of the solution. PSS design challenges arise because of the differences between characteristics and specifications of the embedded sensing system and the product. To fulfill this challenge, knowledge extraction and reuse from these domains is crucial during the design process. To do so, a sensor ontology is used as the backbone of the PSS knowledge-based framework. The focus of this paper is on defining the embedded sensing systems tailored to industrial PSS and the use of these systems in providing customized services. As part of the ICP4Life platform, the paper presents a sensing system ontology as a framework to support the smart services in industrial machinery PSS. An industrial use case is conducted to validate the efficiency of the proposed ontology and to show the benefits of the ICP4Life platform to reduce time and cost of PSS development processes.
Speed is an essential parameter in biomechanical analysis and general locomotion research. It is possible to estimate the speed using global positioning systems (GPS) or inertial measurement units (IMUs). However, GPS requires a consistent signal connection to satellites, and errors accumulate during IMU signals integration. In an attempt to overcome these issues, we have investigated the possibility of estimating the horse speed by developing machine learning (ML) models using the signals from seven body-mounted IMUs. Since motion patterns extracted from IMU signals are different between breeds and gaits, we trained the models based on data from 40 Icelandic and Franches-Montagnes horses during walk, trot, tölt, pace, and canter. In addition, we studied the estimation accuracy between IMU locations on the body (sacrum, withers, head, and limbs). The models were evaluated per gait and were compared between ML algorithms and IMU location. The model yielded the highest estimation accuracy of speed (RMSE = 0.25 m/s) within equine and most of human speed estimation literature. In conclusion, highly accurate horse speed estimation models, independent of IMU(s) location on-body and gait, were developed using ML.
This paper provides an overview of scientific and industrial developments of the last decade in the area of sensor networks in The Netherlands (Low Lands). The goal is to highlight areas in which the Netherlands has made most contributions and is currently a dominant player in the field of sensor networks. On the one hand, motivations, addressed topics, and initiatives taken in this period are presented, while on the other hand, special emphasis is given to identifying current and future trends and formulating a vision for the coming five to ten years. The presented overview and trend analysis clearly show that Dutch research and industrial efforts, in line with recent worldwide developments in the field of sensor technology, present a clear shift from sensor node platforms, operating systems, communication, networking, and data management aspects of the sensor networks to reasoning/cognition, control, and actuation.
In computer systems, the storage hierarchy, composed of a disk drive and a DRAM, is responsible for a large portion of the total energy consumed. This work studies the energy merit of interposing flash memory as a streaming buffer between the disk drive and the DRAM. Doing so, we extend the spin-off period of the disk drive and cut down on the DRAM capacity at the cost of (extra) flash. We study two different streaming applications: mobile multimedia players and media servers. Our simulated results show that for light workloads, a system with a flash as a buffer between the disk and the DRAM consumes up to 40% less energy than the same system without a flash buffer. For heavy workloads savings of at least 30% are possible. We also address the wear- out of flash and present a simple solution to extend its lifetime.