Browsing by Author "Kruger, Carel P"

Now showing 1 - 13 of 13
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    Benchmarking Internet of Things devices
    (IEEE, 2014-07) Kruger, Carel P; Hancke, GP
    The use of commercial off-the-shelf components for implementing Internet of Things devices has become a common practice amongst researchers and solution providers. IOT solutions, based on the Raspberry Pi, BeagleBone and BeagleBone Black, offer cost effective, versatile and uncomplicated platforms for rapid application development. The devices are treated as black box devices and little work has been done to quantify the performance of these devices when the system architecture, software components or communication channels are varied. This paper introduces micro- and macro-benchmarking methods for these devices; quantifying the performance of each device for the varying hardware architectures. Micro-benchmarking was performed using lmbench - a cross platform benchmarking framework for UNIX devices. The macro-benchmarking was implemented using a custom developed CoAP benchmarking utility created using the libCoAP library. The results showed that the selection of the platform processor is a key design requirement and has the most potential to optimise CoAP server performance. The latency associated with the communication channels was found to be a dominating factor for round-trip times associated with CoAP requests.
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    Experimental investigation into deploying a Wi-Fi6 mesh system for underground gold and platinum mine stopes
    (2024-08) Chetty, Brenton L; Walingo, TM; Kruger, Carel P; Isaac, Sherrin J
    Stopes suffer from unreliable wireless communication due to their harsh environment. There is a lack of confidence within industry regarding the effectiveness of existing solutions in providing reliable high-bandwidth performance in hard rock stopes. This work proposes that Wi-Fi6 is a good candidate for reliable high-bandwidth communications in underground hard rock stopes. Experiments in a tunnel and mine stope were conducted to evaluate the performance of Wi-Fi6 in terms of latency, jitter, and throughput. Different criteria, such as multi-hop systems, varying multipath, mesh routing protocols, and frequencies at different bandwidths, were used to evaluate performance. The results show that Wi-Fi6 performance is greater in stopes compared to tunnels. Signal quality evaluations were conducted using the Asus RT-AX53U running OpenWrt, and an additional experiment was conducted on the nrf7002dk running Zephyr OS to evaluate the power consumption of Wi-Fi6 against the industry standard for low-powered wireless communications, IEEE 802.15.4. Wi-Fi6 was found to be more power-efficient than IEEE 802.15.4 for Mbps communications. These experiments highlight the signal robustness of Wi-Fi6 in stope environments and also highlights its low-powered nature. This work also highlights the performance of the two most widely used open-source mesh routing protocols for Wi-Fi.
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    Implementing the Internet of Things vision in industrial wireless sensor networks
    (IEEE, 2014-07) Kruger, Carel P; Hancke, GP
    The authors of this paper explore the use of IPv6 over Low power Wireless Personal Area Networks (6LoWPAN), IPv6 Routing Protocol for Low power and Lossy Networks (RPL) and Constrained Application Protocol (CoAP) as a possible solution for realising the Internet of Things (IOT) vision in Industrial Wireless Sensor Networks (IWSNs). The aim of this paper is to investigate the feasibility of using Internet Engineering Task Force (IETF) standards in industrial environments by identifying and quantifying several attributes of a 6LoWPAN, RPL and CoAP based IWSNs relating to bounded time interval communications. The paper identifies several possible causes of latency in IWSNs and can be used as a basis for deploying Internet Protocol (IP) based IWSNs requiring IOT connectivity.
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    Locomotive monitoring system using wireless sensor networks
    (IEEE, 2014-07) Croucamp, PL; Rimer, S; Kruger, Carel P
    Theft of cables used for powering a locomotive not only stops the train from functioning but also paralyzes the signalling and monitoring system. This means that information on certain locomotive's cannot be passed onto other locomotives which may use the same track at different times hence increasing the possibility of accidents which can be costly. We propose to design and implement a standalone wireless sensor system that can be used to monitor a locomotive and which runs on a separate platform than that used to actually operate the locomotive.
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    Non-invasive sensor network to map stationary bed heights and moving dunes along pipelines larger than NB150
    (Australian Centre for Geomechanics, 2018-04) Ilgner, Hartmut J; Kruger, Carel P
    While the presence of stationary beds is generally regarded as an undesired operating condition, the recent monitoring of industrial pipelines with novel instrumentation has now revealed that beds indeed repeatedly developed under certain operating conditions. The smaller beds depleted routinely after process conditions returned to normal. However, as soon as bed heights increased beyond a certain value, pressures and flow rates were insufficient to prevent subsequent pipeline blockages. This novel instrumentation is now being further enhanced in two ways. Firstly, additional sensors are mounted along the circumference of the pipe so that the actual bed height can be provided as a percentage of the pipe diameter and be used as a single parameter for bed control. Secondly, multiples of these sensor sets can be installed at key locations along the pipeline where settlement is expected. The results from all sensor sets are integrated online for visualisation to provide an instant overview of the actual bed conditions to the operator. In this way the pipeline can intentionally be operated safely with a known bed height. The effects of interventions deployed to change the bed height are immediately available for responsive process control. Based on the experiences from recent field work, the paper concludes with an assessment of trade-offs which were necessary to design a reliable wireless sensor network.
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    Open hardware: a role to play in wireless sensor networks?
    (MDPI, 2015-03) Fisher, R; Ledwaba, Lehlogonolo PI; Hancke, GP; Kruger, Carel P
    The concept of the Internet of Things is rapidly becoming a reality, with many applications being deployed within industrial and consumer sectors. At the ‘thing’ level—devices and inter-device network communication—the core technical building blocks are generally the same as those found in wireless sensor network implementations. For the Internet of Things to continue growing, we need more plentiful resources for building intelligent devices and sensor networks. Unfortunately, current commercial devices, e.g., sensor nodes and network gateways, tend to be expensive and proprietary, which presents a barrier to entry and arguably slows down further development. There are, however, an increasing number of open embedded platforms available and also a wide selection of off-the-shelf components that can quickly and easily be built into device and network gateway solutions. The question is whether these solutions measure up to built-for-purpose devices. In the paper, we provide a comparison of existing built-for-purpose devices against open source devices. For comparison, we have also designed and rapidly prototyped a sensor node based on off-the-shelf components. We show that these devices compare favorably to built-for-purpose devices in terms of performance, power and cost. Using open platforms and off-the-shelf components would allow more developers to build intelligent devices and sensor networks, which could result in a better overall development ecosystem, lower barriers to entry and rapid growth in the number of IoT applications.
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    Smart street lights using power line communication
    (IEEE, 2017-09) Du Toit, P; Kruger, Carel P; Hancke, GP; Ramotsoela, TD
    The increasing popularity of automation has resulted in the development of “smart” systems for a variety of different applications. One such application is street lighting which still mostly uses very primitive methods of maintenance. The use of smart street lighting can significantly reduce power consumption and CO2 emissions and consequently also save money. This paper proposes the use of a smart street lighting system which provides an intelligent method of conserving energy and monitoring street light faults with the use of communication over the power line. The developed system communicates over power lines using modified frequency shift keying (FSK) modulation. The system used an LDR (light dependent resistor) based light sensor and an LED (light emitting diode) luminaire to provide the intelligent control.
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    Towards a demand-side smart domestic electrical energy management system
    (IST Africa 2013 Conference Proceedings, 2013) Dlodlo, N; Smith, Andrew C; Montsi, L; Kruger, Carel P
    Energy conservation concerns call for end-users to regulate their electrical consumption and help achieve a balance between the available energy supply and demand. Therefore there is a need for rigorous research into smart home energy management systems that could assist the end-user in achieving this goal. This paper addresses the issue of electrical energy conservation in the home through the adoption of smart technologies (one instantiation of smart technologies). Smart objects are everyday artefacts augmented with sensing, processing and networking capabilities that enable them not only to communicate with people and other smart objects, but also discover where they are and what objects are in the vicinity. The smart home, on the other hand, is an automated home equipped with smart objects and a home network that is able to transport information between the objects and the Internet. This research focusses on the design and implementation of a smart home energy management system that integrates smart technologies such as the smart phone, cloud, wireless, web server and motes. The research analyses literature on existing smart home energy systems and technologies and draws lessons from the analysis on how the proposed architecture should be structured. When completed this system will allow the end-user to switch single or group of appliances by means of an Android-based smart phone, be they within their home or at a remote location. In emergencies, an authorised authority such as the municipality could potentially control electrical appliances in a whole neighbourhood.
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    Transactive energy: State-of-the-art in control strategies, architectures, and simulators
    (2021-09) Onumanyi, Adeiza J; Isaac, Sherrin J; Kruger, Carel P; Abu-Mahfouz, Adnan MI
    The concept of transactive energy (TE) in smart grid systems is gaining increased research attention for its potential to optimize distributed energy resources, improve system reliability, as well as provide a balanced ecosystem for fair economic transaction between prosumers. TE is defined by the GridWise Architecture Council as a system of economic and control mechanisms that allows the dynamic balance of supply and demand across the entire electrical infrastructure using value as a key operational parameter. With control mechanisms being a key part of TE systems, in this article, we discuss the state-of-the-art in TE control strategies, architectures, and relevant simulators for designing, evaluating, and analysing TE systems. Most importantly, existing TE control strategies are examined and discussed via a hierarchical structure comprising four different levels wherein TE control strategies/controllers can be deployed. Architecturewise, we highlight the different types of TE architectures including the centralized, decentralized, distributed, and hierarchical architecture. In terms of existing and potential simulators for designing and evaluating TE models, we discuss and compare notable software across different characteristics of interest. We conclude this article by highlighting the basic components of a typical TE controller and other future research directions spanning across security concerns, privacy issues, communication challenges, simulation and validation demands. As a main contribution, different from existing survey articles, this article presents a synthesis of existing works regarding TE control strategies, architectures, and TE-based simulators for the benefit of the budding researcher whose interest may lie in the study of TE systems.
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    Transactive energy: State-of-the-art in control strategies, architectures, and simulators
    (2021-09) Onumanyi, Adeiza J; Isaac, Sherrin J; Kruger, Carel P; Abu-Mahfouz, Adnan MI
    The concept of transactive energy (TE) in smart grid systems is gaining increased research attention for its potential to optimize distributed energy resources, improve system reliability, as well as provide a balanced ecosystem for fair economic transaction between prosumers. TE is defined by the GridWise Architecture Council as a system of economic and control mechanisms that allows the dynamic balance of supply and demand across the entire electrical infrastructure using value as a key operational parameter. With control mechanisms being a key part of TE systems, in this article, we discuss the state-of-the-art in TE control strategies, architectures, and relevant simulators for designing, evaluating, and analysing TE systems. Most importantly, existing TE control strategies are examined and discussed via a hierarchical structure comprising four different levels wherein TE control strategies/controllers can be deployed. Architecturewise, we highlight the different types of TE architectures including the centralized, decentralized, distributed, and hierarchical architecture. In terms of existing and potential simulators for designing and evaluating TE models, we discuss and compare notable software across different characteristics of interest. We conclude this article by highlighting the basic components of a typical TE controller and other future research directions spanning across security concerns, privacy issues, communication challenges, simulation and validation demands. As a main contribution, different from existing survey articles, this article presents a synthesis of existing works regarding TE control strategies, architectures, and TE-based simulators for the benefit of the budding researcher whose interest may lie in the study of TE systems.
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    An ultrasonic-based localization system for underground mines
    (IEEE, 2017-07) Jordaan, JP; Kruger, Carel P; Silva, B; Hancke, GP
    Localization is important for a wide range of industries and applications. In underground mining, for instance, it is helpful to know the miners’ locations, particularly in emergency situations. One way this can be achieved is by using ultrasonic based localization. This paper presents the design and implementation of a wireless sensor network which can be deployed in underground mines to perform time-difference-ofarrival based localization. It is shown that the implemented ultrasound receivers are resistant to noisy conditions that may arise in harsh underground environments.
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    Wireless gas sensing in South African underground platinum mines
    (IEEE Xplore, 2014-04) Abu-Mahfouz, Adnan MI; Isaac, Sherrin J; Kruger, Carel P; Niels Aakvaag, N; Britta Fismen, B
    Approximately 70% of South African mines are classified as fiery, where methane gas potentially could cause explosions. The number of flammable gas reports and accidents are increasing steadily for both gold and platinum mines. However, there is less awareness of the hazards of methane in hard rock mines (gold and platinum) than in coal mines. Currently, there is no wireless real-time gas sensing system used in South African hard rock mines. The main objective of this work is to investigate the possibility of using a wireless gas detector called GS01 in underground mines. Several experiments have been conducted to evaluate the GS01 performance, accuracy and the ability to communicate in underground mines. The results demonstrate the suitability of using GS01 in such harsh environments. A second motivation for the work was to evaluate the performance of wireless communication using different frequencies.
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    Wireless Sensor Networks TestBed: ASNTbed
    (IST Africa 2013 Conference Proceedings, 2013-05) Dludla, Angeline G; Abu-Mahfouz, Adnan MI; Kruger, Carel P; Isaac, Sherrin J
    Wireless sensor networks (WSNs) have been used in different types of applications and deployed within various environments. Simulation tools are essential for studying WSNs, especially for exploring large-scale networks. However, WSN testbeds are still required for further testing before the real implementation. In this paper we propose an indoor testbed which is built on the ceiling board of the demonstration room. The purpose of this testbed is to evaluate various types of algorithms and protocols before using them in real world applications. This paper focuses on how to implement such testbed and what are the main challenges that we experienced while implementing the ASNTbed (Advanced Sensor Networks Testbed) and how to solve them. This paper can be considered as a guideline to help other researchers and developers to implement similar testbed.