Laboratory Test Bed Research Articles

Using Mobile Devices for Mixed-Reality Interactionswith Educational Laboratory Test-Beds

This paper explores a novel human–machine interaction (HMI) paradigm that utilizes the sensing, storage, computation, and communication (SSCC) power capabilities of mobile devices to provide intuitive interactions with dynamic systems. The HMI paradigm addresses the fundamental challenges by integrating computer vision, 3D virtual graphics, and touchscreen sensing to develop mobile apps that provide interactive augmented reality (AR) visualizations. While prior approaches used laboratory-grade hardware, e.g., personal computer (PC), vision system, etc., for streaming video to remote users, the approach exploits the inherent mobility of mobile devices to provide users with mixed-reality (MR) environments in which the laboratory test-bed and augmented visualizations coexist and interact in real-time to promote immersive learning experiences that don’t yet exist in engineering laboratories. By pointing the rear-facing cameras of the mobile devices at the system from an arbitrary perspective, computer vision techniques retrieve physical measurements to render interactive AR content or perform feedback control. Future work is expected to examine the potential of our approach in teaching fundamentals of dynamic systems, automatic control, robotics, etc. through inquiry-based activities with students.

Experimental investigation on synchronized optical code division multiple access transmission

In this paper an experimental study on the performance of our previously reported optical CDMA co-channel interference reduction is presented, where an end-to-end synchronized CDMA network, implementing a point-to-point fiber-optic link, is modeled in the laboratory test bed. For the first time, the experimental and simulation results on bit-error rates of various prime code families using this laboratory based optical link are presented and compared both in the presence and absence of our previously reported MAI cancellation scheme. Also, to reduce the simulation time during the transmission and verify our results, we have modeled this system in the OptiSystem software. Our experimental results clearly validate all simulations results that we have reported previously.

A new local backup scheme considering simultaneous faults of protection IEDs in an IEC 61850-based substation

Importance of protection IEDs in IEC 61850-based substations has increased by enhancing performance of IEDs but local backup scheme in the substation is not considered important. In the existing local backup method, two protection IEDs are installed for one protection target. This method is useful for local backup of the IEDs. However, local backup at simultaneous fault of the protection IEDs is not performed in conventional substation because it has limitations on operational environment. However, IEC 61850-based substation improves operational environment with high speed communication network and high performance IEDs; and the simultaneous fault problem can be resolved by developing new devices and schemes. Therefore, this paper proposes a new local backup scheme for simultaneous faults of protection IEDs in an IEC 61850-based substation. The proposed backup scheme is configured as self-supervision-based monitoring, new improved local backup IED, and local backup scheme; and the proposed scheme is implemented and tested using IEC 61850 SISCO library on a laboratory test bed.

Development of a Home Energy Management System in Smart Grids: A Laboratory Test-bed and a Mobile Application

The current electricity grid in Morocco is facing challenges due to its conventional nature. The conventional sources of energy used are one of the major participants in pollution, and they are inefficient and unreliable in securing the national energy security. Morocco is energy dependent as it imports about 97% of its energy needs. To improve the current situation, the energy in the residential sector needs to be managed in order to reduce peak demand, protect the environment, reduce cost, avoid energy deficit, involve consumer, and efficiently use its renewable energy potential. This paper tackles the building blocks of smart grids, namely, the residential microgrid. The paper focuses on developing a home energy management system using a laboratory test-bed and a mobile application on smart devices (phones, tablets, etc.) in order to establish a two-way flow of power and data, and manage residual energy. The design, architecture and implementation of the mobile application and the test-bed are detailed. Test-bed hardware components are described. Methods for testing the application are suggested, and finally, algorithms for home energy demand optimization are presented as an extension of the home energy management mobile application features.

Low-Cost Diagnosis of Rotor Asymmetries in Induction Machines Working at a Very Low Slip Using the Reduced Envelope of the Stator Current

Fault diagnosis of rotor asymmetries in induction machines working at a very low slip, through Fourier-based methods, usually requires a long acquisition time to achieve a high spectral resolution and a high sampling frequency to reduce aliasing effects. However, this approach generates a huge amount of data, which makes its implementation difficult using embedded devices with small internal memory, such as digital signal processors and field programmable gate arrays or devices with low computing power. In this paper, a new simplified diagnostic signal designated as the reduced envelope of the stator current is introduced to address this problem. The reduced envelope signal is built using only one sample of the current per cycle without any further processing, and it is demonstrated that it carries the same spectral information about the fault as the full-length current signal. Based on this approach, an embedded device has only to store and process a minimal set of samples compared with the raw current signal for a desired resolution. In this paper, the theoretical basis of the proposed method is presented, as well as its experimental validation using two different motors with broken bars: 1) a high-power induction motor working in a factory; and 2) a low-power induction motor mounted in a laboratory test bed.

Image quality modeling and characterization of Nyquist-sampled framing sensors with operational considerations for remote sensing

The effect of increasing Q on image interpretability is explored, and the fidelity of general image quality equation (GIQE) predictions is assessed for Nyquist-sampled (Q=2) imagery at low signal-to-noise ratio. A digital image chain simulation is developed and validated against a laboratory test bed using objective and subjective assessments. Using the validated model, additional test cases are simulated to study the effects of increased detector sampling on image quality with operational considerations for space-based remote sensing. Variants of the GIQE are evaluated against subject-provided ratings, and modifications that increase prediction accuracy for Q=2 imagery are proposed. Finally, using the validated simulation and modified image quality equation, trades are conducted to ascertain the feasibility of implementing Q=2 designs in future electro-optical systems.

Validation of Pulsar Phase Tracking for Spacecraft Navigation

Previous theoretical work has shown that pulsars have fascinating potential as aids for autonomous, deep space navigation. In this paper, phase tracking is investigated as a technique to measure the distance traveled by a spacecraft over an observation interval. Phase tracking was experimentally validated using photons emitted by a modulated x-ray source and detected by a silicon-drift detector using the NASA Goddard X-Ray Navigation Laboratory Testbed. Models of the Crab pulsar and PSR B1821-24 were used. Three simulated, one-dimensional trajectories were considered: one stationary, one with constant velocity, and one with constant acceleration. For constant signal frequency, a maximum-likelihood phase estimator was used. Otherwise, the observation window was broken into smaller blocks over which maximum-likelihood phase estimates were looped through a digital phase-locked loop to reduce errors and estimate the Doppler frequency. The maximum-likelihood phase estimator tracked the initial phase within 0.15% for the simulations and 2.5% in the experiments. The maximum-likelihood phase estimator–digital phase-locked loop cascade tracked the phase and frequency in both the simulations and experiments. The phase error and Doppler frequency error tended toward zero in under 250 and 100 s, respectively, with the Crab pulsar.

Ocena skuteczno�ci zak��ce� odzewowych w sieciach mobilnych

This article concerns the issues related to efficiency of intentional jamming, of wireless networks, and their immunity against them. The work presents, the issue of communication jamming and laboratory test bed for response jamming effectiveness evaluation. The automation, methodology and example test results for personal radios are shown. In summary, directions for further work and possibilities of test bed development, are indicated. (Evaluation of response jamming effectiveness in mobile networks). Slowa kluczowe: radiokomunikacja, walka elektroniczna, zaklocanie odzewowe, emulator kanalu radiowego.

An Enforceable Scheme for Packet Forwarding Cooperation in Network-Coding Wireless Networks With Opportunistic Routing

The performance of wireless networks can be significantly improved by using network coding with opportunistic routing. In such a wireless network, selfish nodes may not cooperate when they are supposed to forward packets. This fundamental cooperation problem in packet forwarding is closely related to the incentive problem in network-coding wireless networks with opportunistic routing, and to the incentive-compatible packet-forwarding problem in conventional wireless networks, but different from both of them. In this paper, we propose incentive-compatible packet opportunistic forwarding for network-coding wireless networks (INPAC), a solution using a combination of game-theoretic and cryptographic techniques. We formally prove that, if INPAC is used, then being cooperative in packet forwarding is a subgame perfect equilibrium. That is, nodes have incentives to follow the protocol and forward packets. We have implemented and evaluated INPAC on the Orbit Lab test bed. Our evaluation results verify the incentive compatibility of INPAC and also its efficiency.

Transient Engine Emulation within a Laboratory Testbed for Aircraft Power Systems

Transient Engine Emulation within a Laboratory Testbed for Aircraft Power Systems

Feedback Linearization Control of the Inertia Wheel Pendulum

Abstract In this paper, two feedback linearizing control laws for the stabilization of the Inertia Wheel Pendulum are derived: a full-state linearizing controller, generalizing the existing results in literature, with friction ignored in the description and an inputoutput linearizing control law, based on a physically motivated definition of the system output. Experiments are carried out on a laboratory test bed with significant friction in order to test and verify the suggested performance and the results are presented and discussed. The main point to be made as a consequence of the experimental evaluation is the fact that actually the asymptotic stabilization was not achieved, but rather a limit cycling behavior was observed for the full-state linearizing controller. The input-output linearizing controller was able to drive the pendulum to the origin, with the wheel speed settling at a finite value

System Integration and Hierarchical Power Management Strategy for a Solid-State Transformer Interfaced Microgrid System

This paper investigates, and for the first time presents, the system integration of a novel solid-state transformer (SST) interfaced microgrid system. Accordingly, a hierarchical power management strategy is proposed for this system to enable islanding mode operation, SST enabled operation, and the seamless transfer between two modes. The proposed power management strategy includes three control levels: primary control for the local controller; secondary control for the dc microgrid bus voltage recovery; and tertiary control to manage the battery state of charge. The proposed system architecture and control strategies are detailed in this paper and a lab test bed is constructed to verify the system performance. Finally, several typical case studies are carried out. The experimental results verify the proposed system and distributed power management strategy.

HMTP: Multipath transport protocol for multihoming wireless erasure networks

AbstractThis paper proposes a fountain‐code‐based multipath transport protocol, called heterogeneous multipath transport protocol (HMTP), and evaluates its performance. HMTP improves the throughput performance and path utilisation of multihoming wireless erasure networks. It solves the receive buffer blocking problem and eliminates the need for retransmissions and in‐order packet delivery, both of which severely degrade the performance of existing multipath transport protocols in multihoming networks. The encoding and decoding algorithms of HMTP are based on efficient and computationally inexpensive coding algorithms such as LT codes. To minimise the fountain encoding/decoding overhead, complexity and computational cost while ensuring the desired decoding performance, the appropriate values of the parameters of the LT codes are determined. We implement and extensively evaluate the performance of HMTP using both NS‐2 simulator and an 802.11 wireless local area network laboratory test bed. Our simulations and experimental results show that HMTP significantly outperforms the concurrent multipath transfer stream control transmission protocol, especially in multihoming 802.11 wireless local area networks. Copyright © 2014 John Wiley & Sons, Ltd.

Energy harvesting from organic liquids in micro-sized microbial fuel cells

Micro-sized microbial fuel cells (MFCs) are miniature energy harvesters that use bacteria to convert biomass from liquids into usable power. The key challenge is transitioning laboratory test beds into devices capable of producing high power using readily available fuel sources. Here, we present a pragmatic step toward advancing MFC applications through the fabrication of a uniquely mobile and inexpensive micro-sized device that can be fueled with human saliva. The 25-μl MFC was fabricated with graphene, a two-dimensional atomic crystal-structured material, as an anode for efficient current generation and with an air cathode for enabling the use of the oxygen present in air, making its operation completely mobile and free of the need for laboratory chemicals. With saliva as a fuel, the device produced higher current densities (1190 A m−3) than any previous air-cathode micro-sized MFCs. The use of the graphene anode generated 40 times more power than that possible using a carbon cloth anode. Additional tests were performed using acetate, a conventional organic material, at high organic loadings that were comparable to those in saliva, and the results demonstrated a linear relationship between the organic loading and current. These findings open the door to saliva-powered applications of this fuel cell technology for Lab-on-a-Chip devices or portable point-of-care diagnostic devices. A micro-sized (75 ml) MFC with graphene anode and air cathode fueled by human saliva producing higher current densities (1190 A m−3) than any previous air-cathode micro-sized MFCs and generated 40 times more power than that possible with a carbon cloth anode. In microbial fuel cells, microorganisms in the anode compartment carry out a biochemical reaction that oxidizes the fuel. The electrons produced are transferred to the cathode compartment through an external circuit, generating an electrical current. The development of micro-sized microbial fuel cells is attractive owing to their potential for use in portable devices, such as point-of-care diagnostic units. A team of researchers led by Muhammad M. Hussain at the King Abdullah University of Science and Technology, Saudi Arabia, has now shown that multi-layered graphene serves as an efficient anode material for these devices. The graphene anode was prepared through chemical vapor deposition and combined with an air cathode — which enables the use of oxygen from the air — to produce a mobile 25-microliter microbial fuel cell. When saliva was used as a fuel, good power generation (of nearly 1 microwatt) was observed, holding promise for the development of biointegrated electronics.

New Repetitive Control With Improved Steady-State Performance and Accelerated Transient

In repetitive control (RC), the enhanced servo performance at the fundamental frequency and its higher order harmonics is usually followed by undesired error amplifications at other frequencies. In this paper, we discuss a new structural configuration of the internal model in RC, wherein designers have more flexibility in the repetitive loop-shaping design, and the amplification of nonrepetitive errors can be largely reduced. Compared to conventional RC, the proposed scheme is especially advantageous when the repetitive task is subject to large amounts of nonperiodic disturbances. An additional benefit is that the transient response of this plug-in RC can be easily controlled, leading to an accelerated transient with reduced overshoots. Verification of the algorithm is provided by simulation of a benchmark regulation problem in hard disk drives, and by tracking-control experiments on a laboratory testbed of an industrial wafer scanner.

The Application of Bayesian Change Point Detection in UAV Fuel Systems

A significant amount of research has been undertaken in statistics to develop and implement various change point detection techniques for different industrial applications. One of the successful change point detection techniques is Bayesian approach because of its strength to cope with uncertainties in the recorded data. The Bayesian Change Point (BCP) detection technique has the ability to overcome the uncertainty in estimating the number and location of change point due to its probabilistic theory. In this paper we implement the BCP detection technique to a laboratory based fuel rig system to detect the change in the pre-valve pressure signal due to a failure in the valve. The laboratory test-bed represents a Unmanned Aerial Vehicle (UAV) fuel system and its associated electrical power supply, control system and sensing capabilities. It is specifically designed in order to replicate a number of component degradation faults with high accuracy and repeatability so that it can produce benchmark datasets to demonstrate and assess the efficiency of the BCP algorithm. Simulation shows satisfactory results of implementing the proposed BCP approach. However, the computational complexity, and the high sensitivity due to the prior distribution on the number and location of the change points are the main disadvantages of the BCP approach

Mobile satellite reception with DVB‐SH receiver architecture and performance

SUMMARYWithin the Digital Video Broadcasting (DVB) family of standards, DVB‐SH (satellite to handheld devices) is the first standard for a hybrid system offering parallel reception of satellite and terrestrial signals. In this paper, we discuss the architecture and implementation of a full‐featured DVB‐SH receiver. In addition, a laboratory test bed including a DVB‐SH signal generator that can be used for DVB‐SH system validation and receiver characterization is presented. We provide some key results of receiver performance measurements in typical channel conditions. Finally, we highlight the advantage of a multi‐frequency network configuration in case of a hybrid reception scenario. Copyright © 2013 John Wiley & Sons, Ltd.

Tradable Planning Permits to Control Land Development in Germany: A Laboratory Testbed Experiment

This article reports on the results of a market experiment with a trading system, where several municipalities in Germany were obliged to submit ‘planning permits’ for land development outside existing planning boundaries. This study was motivated by current literature proposals for the design of a nationwide permit scheme and tests this market-based policy with 11 communities in the Hanover Region. Subjects were equipped with specific field data about future building areas and their fiscal impact on community budgets for the period 2010–2024. The experiment consisted of two sessions, the first with urban planners and the second with students. The researchers set a proposed regulatory target and varied the initial allocation method for permits across two treatments. Prior to trading, permits were periodically allocated via grandfathering or increasingly substituted by auctions. Results show that a permit scheme could realize substantial cost savings compared with alternative command and control standards, even under market power (MP) conditions. Market efficiency and gains from trade were lower in the planner session. The substitution of permit auctioning for grandfathering did not lead to significant differences in price development, MP and efficiency.

Impact Analysis of Interference Sources on Data Communication System for CBTC Application

We study the anti-interference performance of the 802.11 system when it works as Data Communication System (DCS) in Communication Based Train Control (CBTC). We first conduct extensive experiments on a 802.11b network to assess the ability on a lab test bed, then the outdoor experiments are also conducted. In the presence of jammer, we find that in each case of interference model, there exists a C/I threshold which determine the DCS-Access Point (DCS-AP) and DCS-Station Adapter (DCS-STA) communication performance. In the outdoor environment, different interference sources are adopted to investigate the data throughput value and other parameters of the DCS system under the critical state.

An open virtual testbed for industrial control system security research

Industrial control system security has been a topic of scrutiny and research for several years, and many security issues are well known. However, research efforts are impeded by a lack of an open virtual industrial control system testbed for security research. This paper describes a virtual testbed framework using Python to create discrete testbed components including virtual devices and process simulators. The virtual testbed is designed such that the testbeds are inter-operable with real industrial control system devices and such that the virtual testbeds can provide comparable industrial control system network behavior to a laboratory testbed. Two virtual testbeds modeled upon actual laboratory testbeds have been developed and have been shown to be inter-operable with real industrial control system equipment and vulnerable to attacks in the same manner as a real system. Additionally, these testbeds have been quantitatively shown to produce traffic close to laboratory systems.