Virtual Instrument Software Research Articles

Instrumentation for Verification of Shunt Active Power Filter Algorithms.

This article presents a comprehensive system for testing and verifying shunt active power filter control methods. The aim of this experimental platform is to provide tools to a user to objectively compare the individual control methods. The functionality of the system was verified on a hardware platform using least mean squares and recursive least squares algorithms. In the experiments, an average relative suppression of the total harmonic distortion of 22% was achieved. This article describes the principle of the shunt active power filter, the used experimental platform of the controlled current injection source, its control system based on virtual instrumentation and control software and ends with experimental verification. The discussion of the paper outlines the extension of the experimental platform with the cRIO RTOS control system to reduce the latency of reference current generation and further planned research including motivation.

Preliminary Development of an upgrade of a chamber to measure the response of quartz crystal resonators

Quartz crystal microbalance (QCM) sensors have been frequently used as weighing devices, since they have proven to be sensitive due to shifts in their resonant frequency due to increments in the mass attached to their surface. These, are normally used as sensor arrays for systems known as "Electronic Noses", to detect and analyze gases, fluids, medical and environmental applications, and biological compounds, among others. For the implementation of such systems, it is necessary to characterize the response of the sensors at different types of compounds, primarily in temperature-controlled environments, which implies the use of control systems with a high cost. This work presents the preliminary design of a static system to measure the response of quartz crystal gas sensors, as a lower cost proposal, using an open-loop controlled temperature environment, through an electronic communication system with the computer and a virtual instrumentation software to monitoring and manipulating the temperature. To observe the effectiveness of the system, real QCM gas sensors with a coat of sensing film of ethyl cellulose were used, applying concentrations of ethanol. In addition, temperatures of 25°C, 35°C and 45°C were adjusted, obtaining typical results of the response of this type of sensors.

Experimental research on terahertz scanning imaging system based on S-parameters

Due to the limitations of the detector in the terahertz (THz) scanning imaging process and the problems of low contrast and poor visualization effect of original image, a THz continuous-wave scanning imaging system from 75 to 110 GHz is presented. The system is comprised of vector network analyzer (VNA), spread spectrum module, transmit and receive antennas, scanning stage and host computer. In addition, the automatic acquisition and storage of S-parameters is realized by Virtual Instrument Software Architecture (VISA) protocol, and the gray imaging method based on S-parameters is proposed. High-precision structural resolution test board is designed based on printed circuit board (PCB) method and the imaging experiment for the resolution test board is carried out. By comparing with original imaging results, better imaging quality of the system designed in this paper is obtained and imaging results show that the resolution of 1.8 mm could be achieved.

Performance analysis and enhancement of brain emotion-based intelligent controller and its impact on PMBLDC motor drive for electric vehicle applications

ABSTRACT Growing awareness of electric vehicles insists on the necessity of Permanent Magnet Brushless Direct Current Motor (PMBLDCM) worldwide. This paper involves building a simulation model of the complete PMBLDCM drive system using Matlab/Simulink to control the speed and Torque. Using the Simulink model, speed parameters with various controllers of the drive system are studied and analyzed. The conventional PI controller is capable of controlling the speed of the PMBLDC motor. H1owever, it cannot give assurance of the stability of the motor throughout the load variation. In a speed loop, Improved Brain Emotional Learning Based Intelligent Controller (IBELBIC) is proposed in this paper. The proposed IBELBIC-based PMBLDC motor drive system with a rating of 3 phase, 30 V, 400 W, 3000 RPM is implemented using Spartan 3 Field Programmable Gate Array (FPGA) from Xilinx. This paper presents an IBELBIC design for enhancing the speed performance of the drive system at various set speeds and different load conditions of 1.2 Nm load, 0.6 Nm load, and no load. The proposed PMBLDCM drive system is realized with the help of a Very high speed integrated circuit Hardware Description Language (VHDL) programming algorithm of digital Pulse Width Modulation (PWM) generator topology. Various test cases are evaluated under different operating conditions to demonstrate the learning capability and the applicability of the proposed controller. In this paper, simulation validation is done using hardware setup, and experimental results are monitored on a computer using a customized program developed using LabVIEW (Laboratory Virtual Instrumentation Engineering Workbench). Instead of a Data Acquisition (DAQ) card, the Virtual Instrument Software Architecture (VISA) tool of LabVIEW software is used in this work and results in cost minimization of the experimental setup.

Power Sharing Control in a Grid-Tied DC Microgrid: Controller Hardware in the Loop Validation

This article presents the development of a low-cost control hardware in the loop platform for the validation and analysis of controllers used for the management of power sharing between the main grid and a DC microgrid. The platform is made up of two parts: a main grid interconnection system emulator (MGISE) and a controller under test (CUT). The MGISE operates on a 260 V DC bus and includes a 1000 W photovoltaic array, a DC variable load and a single H full bridge converter (HFBC). The CUT includes a phase locked loop and a main cascade control structure composed of two PI controllers. Both the MGISE and the CUT were embedded on an NI myRIO-1900 development board and programmed using LabVIEW virtual instrumentation software. These devices communicate with each other using analog signals representing the AC side current, the DC side voltage, and the HFBC control signal. The MGISE operates with an integration time of 6 µs and its performance is validated by comparing it with a simulation in PSIM. The integration time of the MGISE, the development boards used, as well as its programming environment, and the results obtained from the comparison with PSIM simulation, show that the proposed platform is useful for the validation of controllers for power sharing, with a simple implementation process compared to other hardware description methods and with a low-cost platform.

Development of a Didactic Educational Tool for Learning Fuzzy Control Systems

This paper presents the development of a virtual didactic tool for students of mechatronic engineering taking an intelligent system course. The objective of the tool is for students to learn the structures for fuzzy control systems. This tool makes it easier for students to understand the behavior of the membership functions of input and output variables, the evaluation of the set of fuzzy rules, and the method of defuzzification, giving the students the possibility of applying a fuzzy controller in industrial processes using a data acquisition board. The proposed tool was developed with the virtual instrumentation software LabVIEW. It has the advantage that students can manipulate the internal structure of the fuzzy logic control system in a unique window where students can analyze the behavior of internal signals by looking at the response graphs. The fuzzy controller can be easily translated to a real application by using LabVIEW compatible hardware. To have feedback from students on the use of the tool and to understand if this tool allows an improvement in their academic performance, a 2-hour workshop on the proposed application was given to a group of 93 students. At the end of the workshop, a knowledge assessment and a perception survey were applied to the participants. The academic performance achieved by students who were given the workshop using the proposed teaching tool was compared with the academic performance of students who witnessed the workshop using Matlab tools. The statistical analysis of the results obtained for the knowledge assessment shows that the students that had taken the workshop using the proposed teaching tool had better compression of the topic compared to the students that had taken the workshop using the Fuzzy Logic Toolbox provided by Matlab MathWorks. The students that had taken the workshop using the proposed teaching tool obtained a mean grade of 89.63/100, while students that had taken the workshop using Matlab’s tools obtained a mean grade of 69.85/100. Also, the students’ perception of the proposed tool was that it allowed the design of fuzzy control systems in a simple and intuitive way.

SCPI based integrated test and measurement environment using LabVIEW

Test and Measurement processes play a vital role on the quality of hardware functionality testing. Automating these processes provides a better reduction in “time to market” and is more concerned on achieving higher test coverage area when it comes to mass production. Functional testing deals with the observation on the characteristics of the hardware to determine whether it replicates the needs for which it was actually designed. This can be achieved using set of Test and Measurement Instruments which can replicate the environmental condition in which the hardware is to be deployed. This paper provides an environment to integrate set of measurement instruments in a single platform (LabVIEW) and automate the measurement control using command language know as Standard Command for Programmable Instrumentation (SCPI). Script based control commands provide an easy configuration and remote control of instruments. And also programming interface control using Virtual Instrument Software Architecture (VISA) to control instruments using Ethernet and USB protocol.

Two-stage segment linearization as part of the thermocouple measurement chain

An implementation of a two-stage piece-wise linearization method for reduction of the thermocouple approximation error is presented in the paper. First, the whole thermocouple measurement chain of a transducer is described, and possible error is analysed to define the required level of accuracy for linearization of the transfer characteristics. Evaluation of linearization functions and analysis of approximation errors are performed by the virtual instrumentation software package LabVIEW. The method is appropriate for thermocouples and other sensors where nonlinearity varies a lot over the range of input values. The basic principle of this method is to first transform the abscissa of the transfer function by a linear segment look-up table in such a way that significantly nonlinear parts of the input range are expanded before a standard piece-wise linearization. In this way, applying equal-segment linearization two times has a similar effect to non-equal-segment linearization. For a given examples of the thermocouple transfer functions, the suggested method provides significantly better reduction of the approximation error, than the standard segment linearization, with equal memory consumption for look-up tables. The simple software implementation of this two-stage linearization method allows it to be applied in low calculation power microcontroller measurement transducers, as a replacement of the standard piece-wise linear approximation method.

A Wireless Instrumentation Control System Based on Low-Cost Single Board Computer Gateways

Nowadays, most of the automatized measurement processes are carried out by VISA (Virtual Instrument Software Architecture) compatible instruments, that execute the instructions provided by a host computer connected through wired standard buses, as USB (Universal Serial Bus), GPIB (General-Purpose Instrumentation Bus), PXI (PCI eXtensions for Instrumentation) or Ethernet. To overcome the intrinsic limitations associated to these wired systems, this work presents an instrumentation control system based on the IEEE 802.11 wireless communications standard. Intended for instruments having a USB control port, this port is connected to a gateway based on a compact Raspberry Single Board Computer (SBC) and thus the instrument can be connected to the host computer via Wireless Fidelity (WiFi), easily allowing the deployment of an ad-hoc instruments communication network in the working area or its connection to a previously deployed general purpose WiFi network. Developed under Python, the operation commands, wireless link protocol, and USB connection allow two modes of operation to provide system flexibility: a live mode, where commands are sent individually from the host computer to the selected instrument; and a standalone mode, where a full measurement process can be entirely downloaded in the gateway to be autonomously executed on the instrumentation. The system performance in both operation modes, distance of operation, time latencies, and operating lifetime in battery operation have been characterized.

Design y development of a graphical user interface in LabVIEW for acquisition and visualization of climatological data (temperature and relative humidity)

This paper describes the design and development of a Graphical User Interface through the virtual instrumentation software NI LabVIEW using the VISA function, to graphically visualize and storage the data of the climatological variables of temperature and relative humidity. The graphical interface offers the option to export the date, time and data of the two variables to text documents with extension “.txt”, which acquires the information of the electronic board wireless monitoring and control, which uses a main device PIC16F877A microcontroller. AMT1001 Precision Analog Sensor was used to sense temperature and relative humidity. The PIC16F877A was programmed using a C programming language in the CCS Compiler compiler, to the data acquisition, and send it via RS232 communication to the computer, using the PL2303 module USB to TTL converter. To check the GUI operation, the electronic wireless monitoring and control card was connected to the computer equipment by wire, however, the monitoring of the climate variables can be done wirelessly by XBEE technology. Future work aims to monitor the climate of a horticultural greenhouse with XBBE technology, so that the data is sent wirelessly to a computer that has the GUI, and is also connected to Ethernet or WIFI, which will have the LabVIEW graphical interface explained in this article, and the data will be displayed / analyzed through the internet.

A novel test rig development for experimental study of fluid mechanics of hydraulic orifice and/or gaps under high or low temperature conditions

To meet the demand of ever operating in extreme environments of modern high-end vehicles or machineries, it is meaningful to perform basic research on fluid mechanics of hydraulic orifices and/or gaps under high or low temperature conditions. In this study, a novel compact experimental module which integrates the oil, the oil supply mechanism, the testing damping valve with orifices and/or gaps and several sensors was proposed, the experimental module has avoided the bulky method of using a full hydraulic system for oil supply and can be wholly placed into a high/low temperature chamber to undertake experiments; Based on the integrated experimental module, a test rig employing a variable-frequency-motor-driven ball screw driver to excite the testing module was developed. By using the virtual instrument technology, the hardware and software of automatic measurement and control system was further developed, so the automatic control and data collection of the test rig was realized. Final results show that the test rig can conveniently perform fluid mechanics experiments for various hydraulic orifices and/or gaps under high or low temperature conditions with high efficiency, so the test rig can be a very good platform for pertinent basic research works.

Detection of Heart Abnormalities Using Fuzzy Decision Making and Wireless Transmission of Disease Information

Abstract This research work aims to implement the automatic detection of heart abnormality type without doctor’s assessment using electrocardiogram (ECG) features. First, the ECG signal is acquired via Ag-AgCl electrodes, preprocessed using the adaptive Wiener filter to remove the noises and classified with the help of feature extraction techniques and fuzzy decision making (FDM) algorithm. The FDM also finds the type of heart abnormality based on ECG features, such as RRp interval, R peak amplitude detection, and QRS complex interval, and then sends the classified type to the doctor wirelessly via a ZigBee module. The virtual instrument software has been used to validate the proposed concept, and results of both software and hardware parts have been presented to show the effectiveness of the work.

Design of seed respiration measurement system using virtual instrument

In the seed breathing CO2 detection system, the traditional method cannot measure the concentration of CO2 in the seed breathing in real time. According to the characteristics of seed breathing CO2, a seed breathing detection system based on virtual instrument LabVIEW is designed based on tunable diode laser absorption spectroscopy (TDLAS). The system mainly includes laser light source and its controller, seed breathing container based on multiple reflecting pool structure. The upper computer software is mainly set with data acquisition, signal processing, concentration inversion and other functional modules, in which the concentration inversion uses the orthogonal vector phase-locked amplification algorithm to avoid the error caused by the phase difference between the reference signal and the signal to be measured. The experimental results show that the CO2 detection system for seed respiration implemented by virtual instrument software can effectively detect the change of seed respiration, and has good anti-interference and stability, which lays a foundation for the subsequent experimental research and development.

Diseño e implementación de un sistema de medición de respuesta de sensores de gas

Gas sensors are widely used in devices known as electronic Noses. Which are used for the detection of gas leaks, environmental quality and food, etc. However, it is necessary to perform a quantitative and qualitative analysis of these sensors based on the measurement of their response to obtain their characterization. In the present work is shown the design and implementation of a measurement system for gas sensors response. Therefore, a sealed stainless-steel chamber that internally contains the sensors is designed. On the other hand, a temperature controller is implemented using a PID controller governed by an interface developed using virtual instrumentation software. Particularly, this system has the ability to measure the response of gas sensors, such as: metal-oxide and quartz crystal microbalance. The development of this project, presents an alternative to measure the response of sensors to commercial, contemplating a lower cost and same functionality. Measurements were performed at different temperatures, applying samples of ethanol, obtaining typical results in the response of this type of gas sensors. Therefore, it can be said that the system operates satisfactorily.

Multi Axis Robot Coordinate Detection Method Based on LabVIEW

In view of the fact that the need of high precision and safe production of multi-axis robot, a real-time coordinate detection method is designed by using virtual instrument software structure VISA. Programmable multi-axes controller (PMAC) is used as the control system of the lower computer, LabVIEW as the upper computer, PMAC board communicates with the upper computer through industrial Ethernet, and sends command data and pulse signal to the servos through the bus. LabVIEW uses VISA software interface to communicate with the servo drivers, uses Modbus protocol to obtain absolute position data, and calculates the current coordinates of the workbench. Experiments show that the multi-axis robot coordinate detection method based on LabVIEW can realize the coordinate detection of the moving platform, and the following error current value can also be displayed in the working interface.

Generation of Long-time Complex Signals for Testing the Instruments for Detection of Voltage Quality Disturbances

Abstract Software supported procedure for generation of long-time complex test sentences, suitable for testing the instruments for detection of standard voltage quality (VQ) disturbances is presented in this paper. This solution for test signal generation includes significant improvements of computer-based signal generator presented and described in the previously published paper [1]. The generator is based on virtual instrumentation software for defining the basic signal parameters, data acquisition card NI 6343, and power amplifier for amplification of output voltage level to the nominal RMS voltage value of 230 V. Definition of basic signal parameters in LabVIEW application software is supported using Script files, which allows simple repetition of specific test signals and combination of more different test sequences in the complex composite test waveform. The basic advantage of this generator compared to the similar solutions for signal generation is the possibility for long-time test sequence generation according to predefined complex test scenarios, including various combinations of VQ disturbances defined in accordance with the European standard EN50160. Experimental verification of the presented signal generator capability is performed by testing the commercial power quality analyzer Fluke 435 Series II. In this paper are shown some characteristic complex test signals with various disturbances and logged data obtained from the tested power quality analyzer.

Evaluation of natural frequencies and damping ratios of coconut shell particles reinforced epoxy composites

Modal analysis comprises of determination of natural frequency, mode shapes and damping factor of dynamic structures. It is essential in analyzing the response of a structure in real-life situations to avoid resonance condition under excitation. Now a days, composites with natural fiber/particle materials are in considerable demand for structural applications as an alternative material to conventional synthetic fiber composites. However, adequate amount of work on modal analysis of these composites has not been noticed in the literature. The objective of the present work is to evaluate the influence of coconut shell particle size and its volume fraction on natural frequencies and damping factor of coconut shell particles filled epoxy composites. Coconut shell particles reinforced composites (CSPE) were developed using open mould technique with particle sizes of 0.25, 0.5,1 and 2 mm and particle volume fractions of 40%, 50% and 60%. The experimental set up consists of a composite cantilever beam (270 mm × 40 mm × 12 mm), impact hammer, accelerometer and computer interfaced data acquisition system. Acceleration v/s Time plots were acquired using LAB VIEW virtual instrumentation software and converted into Amplitude v/s Frequency plot by Fast Fourier Transform (FFT) using MAT LAB. The natural frequencies are also predicted theoretically and numerically (using ANSYS). The damping ratio was determined using half power band width method. The results reveal that as the particle size and its volume fraction increases, the natural frequency decreases whereas it is vice versa in case of damping factor. The experimental, theoretical and numerical values of natural frequencies are found to be in good agreement. It is concluded that CSPE composites possesses the damping ratios comparable to conventional composite materials such as glass fiber filled epoxy composites.

SOFTWARE BASED EXPERIMENTAL SYSTEM FOR ELECTRICAL POWER QUALITY MEASUREMENT USING THE WIRELESS SENSOR NETWORK MODULES

Experimental system for measurement of standard electrical power quality (PQ) parameters, based on wireless sensor network (WSN), is presented in this paper. System includes generator of reference voltage waveforms, software application for measurement of standard PQ parameters and two microcontroller based wireless sensor modules for transmitting and receiving of measurement results. Reference voltage signals are provided using signal generator with possibility for simulation of typical network disturbances, presented in some previously published papers. This PQ signal generator is functionally supported by the virtual instrumentation software and data acquisition card. Measurements of basic quality parameters for reference test signals are performed using the LabVIEW software application. Time interval for each measurement cycle is 1 s. For communication is used wireless sensor network based on communication standard IEEE 802.15.4 (Zigbee). Hardware configuration includes two wireless sensor modules SPaRCMosquito v.2, based on the microcontroller with Cortex M3 architecture. Transfer of measurement results, between computer and wireless sensor modules on transmitter and receiver points, are provided using standard USB interface.

Diseño de Herramientas Didácticas Enfocadas al Aprendizaje de Sistemas de Control Utilizando Instrumentación Virtual

This paper describes the design of three didactic tools focused on learning of control systems implemented in LabVIEW virtual instruments software. These tools are dedicated to stability analysis in control systems, compensator design using root locus approach and Bode diagrams in the frequency domain. Each of them has a friendly interface with the user. The advantage of these didactic tools is the several options to simulate some characteristics referent to control in contrast with others teaching tools.

Roll Stability Early Warning System Based on Tilt Sensor

In view of the over-speed phenomenon of heavy haul vehicles at high speed, the estimation of the effective range of the dynamic stability and inclination angle of the truck was carried out a rollover stability alarm system based on liquid pendulum angle sensor and virtual instrument software was developed. The working principle and data processing module of tilt sensor are discussed, through the data lines to output analog voltage signal transmitted to the vehicle electronic control unit. A control command is sent by the electronic control unit and sent to the driver via an alarm device, which enables the driver to control the speed in time, and so it reduces the risk of a rollover accident. The results show that the warning system is of good accuracy. The early warning system preventing malignant road traffic accidents has important social significance and actual application value for a safe vehicle.