LabVIEWTM Environment Research Articles

SAFIIRA: A heavy-ion multi-purpose irradiation facility in Brazil

This work describes the new facility for applied nuclear physics at the University of Sao Paulo, mainly for irradiation of electronic devices. It is a setup composed of a quadrupole doublet for beam focusing/defocusing plus multiple scattering through gold foils to produce low intensity, large-area, and high-uniformity heavy-ion beams from 1H to 107Ag. Beam intensities can be easily adjusted from 102 particles cm2/s to hundreds of nA for an area as large as 2.0 cm2 and uniformity better than 90%. Its irradiation chamber has a high-precision motorized stage, and the system is controlled by a LabViewTM environment, allowing measurement automation. Design considerations and examples of use are presented.

FPGA Implementation of Steinhart–Hart Equation for Accurate Thermistor Linearization

This paper presents fixed point operation-based Field Programmable Gate Arrays (FPGA) implementation of Steinhart–Hart Equation (SHHE) for thermistor linearization. FPGA implementation issues of SHHE are presented and their solutions are proposed and experimentally validated in a LabVIEWTM environment. Experimental temperature calibration, performed using a M/S Fluke drywell calibrator, revealed a lowest nonlinearity of 0.11% for an industrial grade thermistor in the input temperature range from −20 °C to 120 °C. Therefore, the main contribution of this work is to demonstrate the lowest nonlinearity for a wider temperature range. This work is expected to be very useful to instrumentation engineers as it employs a time-tested technique, for thermistor linearization in FPGA, leading to the lowest nonlinearity for a larger input temperature range.

A cost-effective instrumented walkway for measuring ground reaction forces in rats to assess gait pattern

Abstract Animal experiments have gained importance in human diseases studies, namely neurological diseases and its biomechanical and physiological aspects. As a model of human disease, the rat offers many advantages over other organisms. For the biomechanical aspects of locomotion these studies are based on the analysis of animals’ kinetic parameters, accessed through a locomotion measurement system. However, these systems are not yet thoroughly developed, are still scarce and are also very expensive when developed for studies using small rodents. In this paper, a system capable of measuring contact forces of small rodents is presented. The platform hardware is based on a 5 × 3 matrix of ultra-sensitive force sensors that produce a set of signals acquired in a LabVIEW TM environment, used for data acquisition and processing. The post processing steps include the removal of null data, curve normalization related to the rat’s weight and expressed as percentage of passage, resulting in a gait pattern. The proposed cost-effective system has achieved excellent results regarding the locomotion profile of healthy animals.

ENERGY MANAGEMENT STRATEGY FOR A FUEL CELL/ULTRACAPASITOR/BATTERY HYBRID SYSTEM FOR PORTABLE APPLICATIONS

A proton exchange membrane (PEM) fuel cells (FCs) with ultracapacitor (UC) and battery (BT) hybrid system has fast transient response compare to stand alone FCs. This hybrid system is promising candidates for environmentally friendly alternative energy sources. An energy management system design and control strategy was introduced in this study. The energy management strategy FC/UC/BT hybrid system model has been developed and the control strategy was programmed in the LabVIEWTM environment and implemented using National Instrument (NI) devices. The energy management strategy is able to manage the energy flow between the main power source (FCs) and auxiliary sources (UC and BT). To control the hybrid system and achieved proper performance, a controller circuit was developed with the three energy sources aligned in parallel to deliver the requested power. The developed model demonstrates the proportion power from the FC, UC and BT under various load demand. Experimental results demonstrate that FC/UC/BT hybrid system operated automatically with the varying load condition. The experimental results are presented; showing that the proposed strategy utilized the characteristic of both energy storage devices thus satisfies the load requirement.

Development of Backtracking Search Optimization Algorithm Toolkit in LabVIEW™

Abstract In this paper a Backtracking Search Optimization Algorithm (BSA) toolkit has been developed in the LabVIEW™ environment. LabVIEW™ provides a graphical programming environment to design measurement and control applications. The development of BSA toolkit was motivated by the fact that only Differential Evolution (DE) toolkit was provided in LabVIEW™. Thus to design BSA toolkit, several modular virtual instruments have been developed for each BSA process. Developed BSA toolkit has been tested on several benchmark test functions and a comparative study with inbuilt DE toolkit has been performed, which shows results obtained from BSA toolkit are found superior to DE toolkit.

200W PEM Fuel Cell Stack with Online Model-Based Monitoring System

Although various designs have been introduced to improve the performance of a Proton Exchange Membrane Fuel Cell (PEMFC) stack system, fault conditions, such as drying or flooding, may still occur due to the complexity of the process. The development of a system which can detect these fault conditions is a key to operate PEMFC stack system effectively. In this study, a monitoring system for a 200W commercial PEMFC stack system has been developed by constructing models for determining the flooding and drying conditions inside the cell. Since the membrane resistance and pressure drop across the stack are important parameters for determining either drying or flooding conditions taking place inside the fuel cell, the online model-based monitoring system is developed by adopting existing algorithms. A number of instruments are installed to measure relevant data. The data acquisition system and mathematical models have been programmed under LabVIEW TM environment. To indicate the abnormal conditions inside the fuel cell stack, the model prediction is compared with the experimental measured values and the size of the discrepancy will be an indicator.

Analyzing spinal deformities by spatial data extracted from computer generated moiré images

Moire measuring method is used widely throughout medical protocols, especially in the field of spinal diagnostics. In this article we will present an image processing method (written in National Instruments™ LabVIEW™ environment) to extract the height coordinates of a human back, by using the information provided by the moire phenomenon formed on the surface. These data can be used to improve the accuracy of the two-dimensional deformation analysis (e.g. determination of Cobb Angle), or the relevance of three-dimensional aberrations (such as vertebral protrusions). DOI: 10.17489/biohun/2013/1/34

Modeling and off-design performance of a 1kWe HT-PEMFC (high temperature-proton exchange membrane fuel cell)-based residential micro-CHP (combined-heat-and-power) system for Danish single-family households

A novel proposal for the modeling and operation of a micro-CHP (combined-heat-and-power) residential system based on HT-PEMFC (High Temperature-Proton Exchange Membrane Fuel Cell) technology is described and analyzed to investigate its commercialization prospects. An HT-PEMFC operates at elevated temperatures, as compared to Nafion-based PEMFCs and therefore can be a significant candidate for cogeneration residential systems. The proposed system can provide electric power, hot water, and space heating for a typical Danish single-family household. A complete fuel processing subsystem, with all necessary BOP (balance-of-plant) components, is modeled and coupled to the fuel cell stack subsystem. The micro-CHP system is simulated in LabVIEW™ environment to provide the ability of Data Acquisition of actual components and thereby more realistic design in the future. A part-load study has been conducted to indicate performance characteristics at off-design conditions. The system is sized to provide realistic dimensioning of the actual system.

Development of a Hybrid (numerical-hydraulic) Circulatory Model: Prototype Testing and Its Response to IABP Assistance

Merging numerical and physical models of the circulation makes it possible to develop a new class of circulatory models defined as hybrid. This solution reduces the costs, enhances the flexibility and opens the way to many applications ranging from research to education and heart assist devices testing. In the prototype described in this paper, a hydraulic model of systemic arterial tree is connected to a lumped parameters numerical model including pulmonary circulation and the remaining parts of systemic circulation. The hydraulic model consists of a characteristic resistance, of a silicon rubber tube to allow the insertion of an Intra-Aortic Balloon Pump (IABP) and of a lumped parameters compliance. Two electro-hydraulic interfaces, realized by means of gear pumps driven by DC motors, connect the numerical section with both terminals of the hydraulic section. The lumped parameters numerical model and the control system (including analog to digital and digital to analog converters)are developed in LabVIEW environment. The behavior of the model is analyzed by means of the ventricular pressure-volume loops and the time courses of arterial and ventricular pressures and flows in different circulatory conditions. A simulated pathological condition was set to test the IABP and verify the response of the system to this type of mechanical circulatory assistance. The results show that the model can represent hemodynamic relationships in different ventricular and circulatory conditions and is able to react to the IABP assistance.

Advanced control: Simulation Tools in Labview Environment

A simulation package developed for advanced control education is reported in this paper. The package is aimed to assists students in acquiring the knowledge and to serve as an easy-to-use demonstration tool for lecturing. The simulation blocks, developed in LabVIEW™ environment, are listed and the effectiveness of the simulation package is demonstrated in examples.

A LabVIEW™-based scanning and control system for proton beam micromachining

LabVIEW™ is steadily gaining in popularity as the programming language of choice for scientific data acquisition and control. This is due to the vast array of measurement instruments and data acquisition cards supported by the LabVIEW™ environment, and the relative ease with which advanced software can be programmed. Furthermore, virtual instruments that are designed for a given system can be easily ported to other LabVIEW™ platforms and hardware. This paper describes the new LabVIEW™ based scanning and control system developed specifically for proton beam micromachining (PBM) applications. The new system is capable of scanning figures at 16-bit resolution with improved sub-microsecond scan rates. Support for electrostatic beam blanking and external dose normalization using a TTL signal have been implemented. The new software incorporates a semi-automated dose calibration system, and a number of novel dose normalization methods. Limitations of the current beam scanning hardware are discussed in light of new results obtained from micromachining experiments performed in SU-8 photoresist.