Real-time sensor data integration in vertical transport systems

In this project, mobile connectivity and an innovative approach to sensor data gathering and integration have been employed to automate maintenance inspection, performance monitoring and ride quality measurement in vertical transportation systems. An Inertial Navigation System (INS) has been proposed, implemented and tested to track lift car movement profile. The inherent characteristics of vertical motion have been used to minimize errors and obtain higher accuracy in the integration results. The measurement of a correlation between kinematic profiles constructed from lift-car tracking data compared to its nominal values provides key information on the lift condition at any time. A frequency analysis was applied to processing vibrations and noise data, effectively adding another dimension to the lift ride quality measurement. This approach enabled lift performance profiles to be compiled automatically and transmitted in real time, which significantly rationalized and improved the process of maintenance inspection and monitoring. An advanced prototype, AdInspect, has been produced, with the full set of described features. Industry partners are currently evaluating it

iMag+: An Accurate and Rapidly Deployable Inertial Magneto-Inductive SLAM System

Localisation is an important part of many applications. Our motivating scenarios are short-term construction work and emergency rescue. These scenarios also require rapid setup and robustness to environmental conditions additional to localisation accuracy. These requirements preclude the use of many traditional high-performance methods, e.g. vision-based, laser-based, Ultra-wide band (UWB) and Global Positioning System (GPS)-based localisation systems. To overcome these challenges, we introduce iMag+, an accurate and rapidly deployable inertial magneto-inductive (MI) mapping and localisation system, which only requires monitored workers to carry a single MI transmitter and an inertial measurement unit in order to localise themselves with minimal setup effort. However, one major challenge is to use distorted and ambiguous MI location estimates for localisation. To solve this challenge, we propose a novel method to use MI devices for sensing environmental distortions for accurate closing inertial loops. We also suggest a robust and efficient first quadrant estimator to sanitise the ambiguous MI estimates. By applying robust simultaneous localisation and mapping (SLAM), our proposed localisation method achieves excellent tracking accuracy and can improve performance significantly compared with only using a Magneto-inductive device or inertial measurement unit (IMU) for localisation

OBTAINING HYSTERESIS LOOPS AT LOW FREQUENCY FOR CHARACTERIZATION OF MATERIALS TO BE USED IN BIOMEDICAL APPLICATIONS

The promising development of magnetic sensors in biomedical field demands an appropriate level of understanding of the magnetic properties of the materials used in their fabrication. To date only few of the types of magnetic materials are encountered where their magnetic properties, characterization techniques and magnetization behavior are yet to be explored more suitably in the light of their applications. This research work studies the characterization of materials by using a cost effective and simple circuit consisting of inductive transducer and an OP-AMP as a voltage integrator. In this approach the circuit was simulated using PSPICE and experiments have been conducted to achieve the desired results. The simulation and experimental results are obtained for three test materials namely iron, steel and plastic. The novelty lies in applying the simple circuit for material testing and characterization via obtaining simulation results and validating these results through experiment. The magnetic properties in low external magnetic field are studied with materials under test. The magnetization effect of a magneto-inductive sensor is detected in low frequency range for different magnetic core materials. The results have shown magnetization behaviour of magnetic materials due to the variation of permeability and magnetism. The resulted hysteresis loops appeared to have different shapes for different materials. The magnetic hysteresis loop found for iron core demonstrated a bigger coercive force and larger reversals of magnetism than these of steel core, thus obtaining its magnetic saturation at a larger magnetic field strength. The shape of the hysteresis loop itself is found to be varying upon the nature of the material in use. The resulted magnetization behaviors of the materials proved their possible applicability for use in sensing devices. The key concern of this work is found upon selecting the appropriate magnetic materials at the desired frequency of operation for magneto resistive applications, magneto-resistive sensors and for an extensive range of biomedical sensor application.

Signals in the Soil: An Introduction to Wireless Underground Communications

In this chapter, wireless underground (UG) communications are introduced. A detailed overview of WUC is given. A comprehensive review of research challenges in WUC is presented. The evolution of underground wireless is also discussed. Moreover, different component of UG communications is wireless. The WUC system architecture is explained with a detailed discussion of the anatomy of an underground mote. The examples of UG wireless communication systems are explored. Furthermore, the differences of UG wireless and over-the-air wireless are debated. Different types of wireless underground channel (e.g., In-Soil, Soil-to-Air, and Air-to-Soil) are reported as well

A Survey on Subsurface Signal Propagation

Wireless Underground Communication (WUC) is an emerging field that is being developed continuously. It provides secure mechanism of deploying nodes underground which shields them from any outside temperament or harsh weather conditions. This paper works towards introducing WUC and give a detail overview of WUC. It discusses system architecture of WUC along with the anatomy of the underground sensor motes deployed in WUC systems. It also compares Over-the-Air and Underground and highlights the major differences between the both type of channels. Since, UG communication is an evolving field, this paper also presents the evolution of the field along with the components and example UG wireless communication systems. Finally, the current research challenges of the system are presented for further improvement of the WUCs

Energy harvesting and wireless transfer in sensor network applications: Concepts and experiences

Advances in micro-electronics and miniaturized mechanical systems are redefining the scope and extent of the energy constraints found in battery-operated wireless sensor networks (WSNs). On one hand, ambient energy harvesting may prolong the systems lifetime or possibly enable perpetual operation. On the other hand, wireless energy transfer allows systems to decouple the energy sources from the sensing locations, enabling deployments previously unfeasible. As a result of applying these technologies to WSNs, the assumption of a finite energy budget is replaced with that of potentially infinite, yet intermittent, energy supply, profoundly impacting the design, implementation, and operation of WSNs. This article discusses these aspects by surveying paradigmatic examples of existing solutions in both fields and by reporting on real-world experiences found in the literature. The discussion is instrumental in providing a foundation for selecting the most appropriate energy harvesting or wireless transfer technology based on the application at hand. We conclude by outlining research directions originating from the fundamental change of perspective that energy harvesting and wireless transfer bring about