Data Acquisition Control Research Articles

Automatic emissive probe apparatus for efficient plasma potential measurements.

The improved inflection point method of emissive probe is the most accurate method for plasma potential measurements, but its manual operation is quite cumbersome and time-consuming. This paper describes the design and test of an automatic emissive probe apparatus for efficient plasma potential measurements. The apparatus consists of a computer controlled data acquisition (DAQ) card, a working circuit composed of a biasing unit and a heating unit, as well as the emissive probe. The main feature of the apparatus is that both the biasing scan and the heating scan of the probe are controlled by the computer program through analog outputs of the DAQ card, which easily realizes the required timing between the biasing and heating scans of the probe. The apparatus can automatically execute the improved inflection point method of emissive probe and give the plasma potential result. The advantages of high-accuracy, high-efficiency, and durability of probe filament make the apparatus promising for extensive use in plasma potential measurements.

Design of Measuring System for Conical Shell Gluing Platform and Analysis of Factors Influencing Measurement

As a cover to prevent the inside system from being destroyed, conical shell is widely used in national defense and meteorological fields. Radial runouts at specific cross sections of conical shell need to be measured before and after gluing for coaxiality requirement between conical shell and connecting ring. So a measuring system of vertical gluing platform was designed. Noncontact laser displacement sensor was adopted in the measuring system for advantages of quick data acquisition, high measuring accuracy and no surface scratch. Compared with traditional measuring method by a dial indicator, laser displacement sensor is more appropriate to carry out the measurement on the surface of conical shell. An open CNC system was developed for the measurement. It was based on industry personal computer (IPC) which and took motion control board and data acquisition board as its core. Experiments were conducted on the designed measuring system to find out the factors which influence measuring results. Measuring data showed that measuring results appeared to be a parabolic distribution in the working range of the sensor and the symmetry axis of the parabola was at the middle position. The variation of incident angle has no obvious influence on measuring results.

Abstracting application deployment on Cloud infrastructures

Deploying a complex application on a Cloud-based infrastructure can be a challenging task. In this contribution we present an approach for Cloud-based deployment of applications and its present or future implementation in the framework of several projects, such as “!CHAOS: a cloud of controls” [1], a project funded by MIUR (Italian Ministry of Research and Education) to create a Cloud-based deployment of a control system and data acquisition framework, “INDIGO-DataCloud” [2], an EC H2020 project targeting among other things high-level deployment of applications on hybrid Clouds, and “Open City Platform”[3], an Italian project aiming to provide open Cloud solutions for Italian Public Administrations. We considered to use an orchestration service to hide the complex deployment of the application components, and to build an abstraction layer on top of the orchestration one. Through Heat [4] orchestration service, we prototyped a dynamic, on-demand, scalable platform of software components, based on OpenStack infrastructures. On top of the orchestration service we developed a prototype of a web interface exploiting the Heat APIs. The user can start an instance of the application without having knowledge about the underlying Cloud infrastructure and services. Moreover, the platform instance can be customized by choosing parameters related to the application such as the size of a File System or the number of instances of a NoSQL DB cluster. As soon as the desired platform is running, the web interface offers the possibility to scale some infrastructure components. In this contribution we describe the solution design and implementation, based on the application requirements, the details of the development of both the Heat templates and of the web interface, together with possible exploitation strategies of this work in Cloud data centers.

A Testing System for a Safety Lock based on LabVIEW

This paper proposes an accurate and efficient testing system for the safety lock that is used in the suspended access platforms. The measurement methods conform to the standard EN 1808:2015. First, the whole architecture of the system is designed, including the mechanical structure unit, lower control unit, sensors and data acquisition. Second, the upper control software based on LabVIEW is presented. In addition, manual and automatic testing modes are proposed. The field experimental results demonstrated that the proposed testing system has the advantage of high accuracy, high automation and high efficiency.

Simple Harmonics Motion experiment based on LabVIEW interface for Arduino

In this work, we developed an affordable modern innovative physics lab apparatus. The ultrasonic sensor is used to measure the position of a mass attached on a spring as a function of time. The data acquisition system and control device were developed based on LabVIEW interface for Arduino UNO R3. The experiment was designed to explain wave propagation which is modeled by simple harmonic motion. The simple harmonic system (mass and spring) was observed and the motion can be realized using curve fitting to the wave equation in Mathematica. We found that the spring constants provided by Hooke’s law and the wave equation fit are 9.9402 and 9.1706 N/m, respectively.

Overview of Keda Torus eXperiment initial results

The Keda Torus eXperiment (KTX) is a new reversed field pinch (RFP) device at the University of Science and Technology of China. The construction and assembly of KTX, including the vacuum chamber, conducting shell, magnetic field windings, power supply system, active control coils, vacuum pump and data acquisition system, have been completed on August 1, 2015. Immediately following that, the first plasma was obtained on August 15, 2015. Intensive conditioning of the machine is underway to ramp up the plasma current toward its full operation. An active feedback mode control system has been built and has been implemented to control the error field around the vertical gaps of the conducting shell. The pulsed power supply systems of ohmic heating field and toroidal field (TF), using thyristor and energy storage capacitors, have been tested and commissioned. The TF power supply has flexibility in being able to operate with a reversed TF configuration and stable TF configuration. The fundamental diagnostic tools are developed for early KTX operation. Currently, the plasma current is up to 205 kA and the maximum discharge length is 21 ms, approaching to the conducting shell penetration time. Furthermore, typical RFP discharges are being produced with RFP state lasting 2 ms. These initial operation results for KTX are described in detail.

Positive ion mass spectrometry for fragmentation of anthracene by low energy electron impact

SynopsisWe have studied the fragmentation of anthracene molecules induced by low energy electron impact. A reflectron time-of-flight mass spectrometer has been used to mass resolve and detect positively charged fragments. Using computer controlled data acquisition, mass spectra have been measured as a function of electron impact from 5 to 100 eV. The mass spectra show clear indications of double and triple ionization. Ion yield curves and appearance energies for most of the positive ions have been extracted from the data.

Hard real-time closed-loop electrophysiology with the Real-Time eXperiment Interface (RTXI).

The ability to experimentally perturb biological systems has traditionally been limited to static pre-programmed or operator-controlled protocols. In contrast, real-time control allows dynamic probing of biological systems with perturbations that are computed on-the-fly during experimentation. Real-time control applications for biological research are available; however, these systems are costly and often restrict the flexibility and customization of experimental protocols. The Real-Time eXperiment Interface (RTXI) is an open source software platform for achieving hard real-time data acquisition and closed-loop control in biological experiments while retaining the flexibility needed for experimental settings. RTXI has enabled users to implement complex custom closed-loop protocols in single cell, cell network, animal, and human electrophysiology studies. RTXI is also used as a free and open source, customizable electrophysiology platform in open-loop studies requiring online data acquisition, processing, and visualization. RTXI is easy to install, can be used with an extensive range of external experimentation and data acquisition hardware, and includes standard modules for implementing common electrophysiology protocols.

Versatile synchronized real-time MEG hardware controller for large-scale fast data acquisition.

Versatile controllers for accurate, fast, and real-time synchronized acquisition of large-scale data are useful in many areas of science, engineering, and technology. Here, we describe the development of a controller software based on a technique called queued state machine for controlling the data acquisition (DAQ) hardware, continuously acquiring a large amount of data synchronized across a large number of channels (>400) at a fast rate (up to 20 kHz/channel) in real time, and interfacing with applications for real-time data analysis and display of electrophysiological data. This DAQ controller was developed specifically for a 384-channel pediatric whole-head magnetoencephalography (MEG) system, but its architecture is useful for wide applications. This controller running in a LabVIEW environment interfaces with microprocessors in the MEG sensor electronics to control their real-time operation. It also interfaces with a real-time MEG analysis software via transmission control protocol/internet protocol, to control the synchronous acquisition and transfer of the data in real time from >400 channels to acquisition and analysis workstations. The successful implementation of this controller for an MEG system with a large number of channels demonstrates the feasibility of employing the present architecture in several other applications.

Design of Feed Control System for Micro EDM Machine Tool

This paper designs the closed-loop feedback control system of MEDM, which is based on the motion control card and data acquisition card. To ensure the accuracy of the process, the gap can be regulated through the analysis of discharge condition and the analysis and treatment of the gap voltage, and then a servo control scheme on small holes machining is presented. Through this way, the electrode loss compensation scheme can be solved, which can improve the efficiency and practicality of MEDM.

A PC-based shutter glasses controller for visual stimulation using multithreading in LabWindows/CVI

Background and objectives: Amblyopia, commonly known as “lazy eye,” is poor vision in an eye from prolonged neurologic suppression. It is a major public health problem, afflicting up to 3.6% of children, and will lead to lifelong visual impairment if not identified and treated in early childhood. Traditional treatment methods, such as occluding or penalizing the good eye with eye patches or blurring eye drops, do not always yield satisfactory results. Newer methods have emerged, based on liquid crystal shutter glasses that intermittently occlude the better eye, or alternately occlude the two eyes, thus stimulating vision in the “lazy” eye. As yet there is no technology that allows easy and efficient optimization of the shuttering characteristics for a given individual. The purpose of this study was to develop an inexpensive, computer-based system to perform liquid crystal shuttering in laboratory and clinical settings to help “wake up” the suppressed eye in amblyopic patients, and to help optimize the individual shuttering parameters such as wave shape, level of transparency/opacity, frequency, and duty cycle of the shuttering.Methods: We developed a liquid crystal glasses controller connected by USB cable to a PC computer. It generates the voltage waveforms going to the glasses, and has potentiometer knobs for interactive adjustments by the patient. In order to achieve good timing performance in this bidirectional system, we used multithreading programming techniques with data protection, implemented in LabWindows/CVI.Results: The hardware and software developed were assessed experimentally. We achieved an accuracy of ±1Hz for the frequency, and ±2% for the duty cycle of the occlusion pulses. We consider these values to be satisfactory for the purpose of optimizing the visual stimulation by means of shutter glasses. The system can be used for individual optimization of shuttering attributes by clinicians, for training sessions in clinical settings, or even at home, aimed at stimulating vision in the “lazy” eye.Conclusions: Multithreading offers significant benefits for data acquisition and instrument control, making it possible to implement time-efficient algorithms in inexpensive yet versatile medical instrumentation with only minimum requirements on the hardware.

Shipborne Over- and Under-Water Integrated Mobile Mapping System and Its Seamless Integration of Point Clouds

ABSTRACTThe rapid acquisition techniques of over- and under-water geoinformation is urgently needed. The Shipborne Over- and Under-water integrated Mobile Mapping System (SiOUMMS) applies plug-in and multi-process network technology to achieve integrated data acquisition and cooperative control of multi-sensors, such as Global Navigation Satellite System, Inertial Measurement Unit, laser scanner, and multi-beam echo sounder. The proposed system can meet the requirements of diverse application scenarios and sensors, allowing for flexibility and scalability. Meanwhile, coarse calibration based on a set of common points and fine calibration using the plane feature constraint are proposed for integratedly obtaining the exterior orientation elements of the laser scanner and the multi-beam echo sounder. Together, these methods provide theoretical support and technical help to the seamless integration of over- and under-water point clouds. Experiments are also described, proving that the root mean square error of over-water point clouds is 0.133 m, the average elevation clearance spacing between adjacent over- and under-water point clouds is less than 0.3 m, and the average horizontal clearance spacing is less than 0.2 m. At the same time, cases in this paper show that SiOUMMS has made important achievements in the integrated measurement of reefs, coastal zone, and inland waterways, and has broad prospects for future applications.

Instrumentation and control system architecture of ECRH SST1

The Electron Cyclotron Resonance Heating (ECRH) system is an important heating system for the reliable start-up of tokamak. The 42GHz and 82.6GHz Gyrotron based ECRH systems are used in tokomaks SST-1 and Aditya to carry out ECRH related experiments. The Gyrotrons are high power microwave tubes used as a source for ECRH systems. The Gyrotrons need to be handled with optimum care right from the installation to its Full parameter control operation. The Gyrotrons are associated with the subsystems like: High voltage power supplies (Beam voltage and anode voltage), dedicated crowbar system, magnet, filament and ion pump power supplies and cooling system. The other subsystems are transmission line, launcher and dummy load. A dedicated VME based data acquisition & control (DAC) system is developed to operate and control the Gyrotron and its associated sub system. For the safe operation of Gyrotron, two level interlocks with fail-safe logic are developed. Slow signals that are operated in scale of millisecond range are programmed through software and hardware interlock in scale of microsecond range are designed and developed indigenously. Water-cooling and the associated interlock are monitored and control by data logger with independent human machine interface.

FPGA SoC Based Multichannel Data Acquisition System with Network Control Module

Normally, Data acquisition (DAQ) is used to acquire the signals from different devices like sensors, transducers, actuators etc. The data acquisition is also used to analyze the signals, digitizing the signals and acquiring the signals from different inputs. The main drawbacks in data acquisition system are data storage, hardware size and remote monitoring. The System-on-Chip Field Programmable Gate Array (SoC-FPGA) is used in the proposed system in the aim to reduce the hardware and memory size. Further to provide remote monitoring with Ethernet/Wi-Fi, the Network Control Module (NCM) is integrated with Data acquisition and processing module for the communication between the systems. This developed system achieves high resolution with memory reduction, reduced hardware size, fast remote monitoring and control. It is used for real time processing in DAQ and signal processing. For fault tolerance and portability, the full system reconfigurability based FPGA acts as the best solution and the system can be reused with different configurations. The control of data acquisition and the subsequent management of data are coded in LabVIEW. LabVIEW tool is used to design and develop a four-channel Data Acquisition and Processing (DAQP) unit. National Instruments Data Acquisition (NIDAQ) and National Instruments Field Programmable Gate Array (NIFPGA) are used to test and implement the design for real time processing. This is designed to provide high accuracy, storage and portability.

Service data acquisition and onboard control for “GRIS-BD” unit in “GRIS” space experiment

Problems of onboard space scientific devices control, collecting auxiliary service information about working capacity, conditions of experiment carrying out and preliminary data processing for real time calibration and stabilizing of operational parameters are actual for any space devices. In this paper we describe and discuss service data acquisition and onboard control for “GRIS-BD” unit in “GRIS” space experiment onboard ISS. This system provides temperature measurements in different equipment parts (in power supplies, on scintillation crystals for energy ranges correction, etc.), precision thresholds measurements in discrimination circuits, status different switching on/off (in real time), precision control detector parameters by high-voltage regulation, fine thresholds changing (analog regulation), different switching on/off (in real time), statistical analysis of data flows and change of operation modes of the device.

A Reduced-Order Controller Considering High-Order Modal Information of High-Rise Buildings for AMD Control System with Time-Delay

Time-delays of control force calculation, data acquisition, and actuator response will degrade the performance of Active Mass Damper (AMD) control systems. To reduce the influence, model reduction method is used to deal with the original controlled structure. However, during the procedure, the related hierarchy information of small eigenvalues will be directly discorded. As a result, the reduced-order model ignores the information of high-order mode, which will reduce the design accuracy of an AMD control system. In this paper, a new reduced-order controller based on the improved Balanced Truncation (BT) method is designed to reduce the calculation time and to retain the abandoned high-order modal information. It includes high-order natural frequency, damping ratio, and vibration modal information of the original structure. Then, a control gain design method based on Guaranteed Cost Control (GCC) algorithm is presented to eliminate the adverse effects of data acquisition and actuator response time-delays in the design process of the reduced-order controller. To verify its effectiveness, the proposed methodology is applied to a numerical example of a ten-storey frame and an experiment of a single-span four-storey steel frame. Both numerical and experimental results demonstrate that the reduced-order controller with GCC algorithm has an excellent control effect; meanwhile it can compensate time-delays effectively.

EPICS-based control system and data acquisition system of small angle X-ray scattering beamline

EPICS-based control system and data acquisition system of small angle X-ray scattering beamline

Design and implementation of a platform for experimental testing and validation of analog-to-digital converters: static and dynamic parameters

This paper presents an implementation of a data acquisition system for analog-to-digital converters (ADCs) using “Laboratory Virtual Instrument Engineering Workbench (LabVIEW)” as software for data analysis. The designed and implemented platform allows interaction with the device under test through means of data acquisition and instrument controls. Developing custom tests in LabVIEW can result in reduced test time, which in turn will help reduce costs in testing. This system was developed for evaluation purposes of ADC's static and dynamic parameters (gain error, offset error, DNL, INL, SNR, SINAD, IMD, etc.) using single and multi-frequency signals. The virtual control and analysis instrument was created in “LabVIEW” environment to control test signals generation and data acquisition. The testing performance of the platform is demonstrated using the classical ADC circuit “ADC0804”. A comparison with experimental results obtained by CANTEST platform from Bordeaux University (France) is also presented to highlight our platform.

Microcontroller Based Prototype for Reactive Power Compensation in Local Distribution Networks

Efficient use of electricity could be a way by which significant savings can be achieved. One of the most important is represented by the improvement of the power supply quality through power factor correction to optimal values. This paper aims to present an implementation of a solution for power factor correction in the distribution networks of consumers using modern technology based on real time data acquisition, signal processing and numerical controls by using programmed in high-level languages microcontrollers. The paper describes the experimental prototype and the test results to determine the performance of the proposed solution are also presented.

Fault Diagnosis of Wind Turbine Gearboxes Through Temperature and Vibration Data

Gearbox faults are one of the most common and severe causes of energy losses in large wind turbine technology. Further, degradation of gearboxes is an elusive phenomenon by the point of view of diagnostics. Yet, nowadays the widespread diffusion of Supervisory Control And Data Acquisition (SCADA) control systems is a keystone for fault prevention. It is desirable to conjugate accuracy of the outputs with intuitiveness and reasonable computational cost. The present work deals with these issues: some methods are proposed for data mining of SCADA gearbox temperature and vibration measurements. In particular, a model based on Artificial Neural Networks (ANN) is proposed and its performances are compared against similar approaches in the literature. It arises that vibration analysis at the time scale of SCADA data isn’t effective for fault diagnosis, even if powered by the artificial intelligence of the ANN, while the proposed ANN model for gearbox temperatures is useful for early fault diagnosis. The method is tested on the data sets of a wind farm in southern Italy and it is shown that the method is capable of diagnosing incoming faults to three out of nine wind turbines of the site.