DEVELOPMENT OF VIRTUAL INSTRUMENT IN CHARACTERISTIC ANALYSIS OF ROTATING MACHINERY BASED ON INSTANTANEOUS FREQUENCY ESTIMATION

Based on the recently quick-developing time-frequency analysis (TFA)technique and virtual instrument (VI) technique, a virtual instrument in characteristic analysis ofrotating machinery is researched and developed successfully. By utilizing instantaneous frequencyestimation (IFE) theoretics of TFA technique, and based on IFE of peak searching on thetime-frequency spectrum, order analysis (OA) functions is put forward and implemented, such as orderspectrum, order spectrum matrix, order tracking, order tracking filtering, and order componentextraction, etc. Unlike the home and abroad existing popular characteristic analyzers, which needkey phasing devices such as shaft encoder, phase-locked loop (PLL), phase-locked multiple frequency,tachometer, etc, to implement constant angle sampling directly or indirectly, whereas thisinstrument only uses the vibration signal of rotating machinery to carry out OA. This instrumentmakes up the shortage of these traditional instruments in analyzing the non-stationary signal ofrun-up and run-down process of rotating machinery. Therefore, it is a great breakthrough for theexisting order analyzers.

V–L decomposition of a novel full-waveform lidar system based on virtual instrument technique

A novel three-dimensional（3D） imaging lidar system which is based on a virtual instrument technique is introduced in this paper. The main characteristics of the system include： the capability of modeling a 3D object in accordance with the actual one by connecting to a geographic information system（GIS）, and building the scene for the lidar experiment including the simulation environment. The simulation environment consists of four parts： laser pulse, atmospheric transport,target interaction, and receiving unit. Besides, the system provides an interface for the on-site experiment. In order to process the full waveform, we adopt the combination of pulse accumulation and wavelet denoising for signal enhancement.We also propose an optimized algorithm for data decomposition： the V-L decomposition method, which combines Vondrak smoothing and laser-template based fitting. Compared with conventional Gaussian decomposition, the new method brings an improvement in both precision and resolution of data decomposition. After applying V-L decomposition to the lidar system, we present the 3D reconstructed model to demonstrate the decomposition method.

The Design and Implementation of the Network Interactive Virtual Experiment Platform for Electronic Information Courses

Experimental teaching plays a crucial role in the trainings of students＇ abilities to analyze and solve problems. Therefore, it is very necessary to continuously carry out experiment teaching reform, improve experiment teaching methods and means, and comprehensively open laboratories so as to provide students with more opportunities of doing experiments. To improve the teaching effect of electronic information experimental courses, a network interactive virtual experimental platform is developed. This platform allows students to finish the construction of all kinds of circuit structures and test virtual instruments in a simulation environment, upload experimental data and also interactively communicate with teachers through the lnternet. The platform can be applied to the teaching activities of related electronic information experimental courses, and also can be used as an aid teaching method for theory teachers. Therefore, it possesses a very good interactivity, and makes up the disadvantages of the experimental teaching in hardware environment, so that a feasible solution is provided for the opening of laboratories.

A Method for Modeling the Virtual Instrument Automatic Test System Based on the Petri Net

Virtual instrument is playing the important role in automatic test system. This paper introduces a composition of a virtual instrument automatic test system and takes the VXIbus based a test software platform which is developed by CAT lab of the UESTC as an example. Then a method to model this system based on Petri net is proposed. Through this method, we can analyze the test task scheduling to prevent the deadlock or resources conflict. At last, this paper analyzes the feasibility of this method.

Reconstruction Model of Ocean Observing Complex Virtual Instrument

With the newly proposed Global Ocean Observing Integration, ocean observing scope has been expanded from the region to the global, therefore the need of large-scale ocean observing system integration has become more and more urgent. Currently, ocean observing systems enabled ocean sensor networks are commonly developed by different organizations using specific technologies and platforms, which brings several challenges in ocean observing instrument （OOI） access and ocean observing system seamless integration. Furthermore, the development of ocean observing systems often suffers from low efficiency due to the complex prograrmning and debugging process. To solve these problems, a novel model, Complex Virtual Instrument （CVI） Model, is proposed. The model provides formal definitions on observing instrument description file, CVI description file, model calculation method, development model and interaction standard. In addition, this model establishes mathematical expressions of two model calculation operations, meanwhile builds the mapping relationship between observing instrument description file and CVI description file. The CVI based on the new model can achieve automatic access to different OOIs, seamless integration and communication for heterogeneous environments, and further implement standardized data access and management for the global unified ocean observing network. Throughout the development, integration and application of such CVI, the rationality and feasibility of the model have been evaluated. The results confirm that the proposed model can effectively implement heterogeneous system integration, improve development efficiency, make full usage of reusable components, reduce development cost, and enhance overall software system quality. We believe that our new model has great significance to promote the large-scale ocean observing system integration.

Virtual Instrument System for Teaching Lab

Virtual Instruments, which have the most brilliant prospect in the domain of instruments, are the combination of the computers and traditional instruments. According to the constructions and the characters of the Teaching Lab Instruments, the paper introduces the principle and design of Virtual Instrument System. Meanwhile, a practical application is indicated.

A virtual logic analyzer implemented with Arduino

A simple,stable and reliable virtual logic analyzer is presented. The logic analyzer had two modules:one was the test pattern generation module,the other was the logic monitoring module. Combining the two modules,one is able to test a digital circuit automatically. The user interface of the logic analyzer was programmed with LabVIEW. Two Arduino UNO boards were used as the hardware targets to input and output the logic signals. The maximum pattern update rate was set to be 20 Hz. The maximum logic sampling rate was set to be 200 Hz. After twelve thousand cycles of exhaustive tests,the logic analyzer had a 100% accuracy. As a tutorial showing how to build virtual instruments with Arduino,the software detail is also explained in this article.

MEMS Test System Based on Virtual Instrument Technology

On account of the multiformity of MEMS devices, it is necessary to integrate with some optical measurement techniques for meeting static and dynamic unit test requirements. In this paper, an automated MEMS test system is built of some commercially available components and instruments based on virtual instrument technology. The system is integrated with stroboscopic imaging, computer micro-vision, microscopic Mirau phase shifting interferometry, and laser Doppler vibrometer, and is used for the measurement of full-view in-plane and out-of-plane geometric parameters and periodical motions and single spot out-of-plane transient motion. The system configuration and measurement methods are analyzed, and some applications of the measurement of in-plane and out-of-plane dimensions and motions were described. The measurement accuracy of in-plane dimensions and out-of-plane dimensional is better than 0.2 um and 5 nm respectively. The resolution of measuring in-plane and out-of-plane motions is better than 15 nm and 2 nm respectively.

Parameter Test of ROIC for IRFPA Based on Virtual Instrument Technology

The readout integrated circuit (ROIC) technology is one of the critical technologies in the research of an infrared focal plane array (IRFPA). Based on the virtual instrument technology, a system for parameter test of ROIC is developed for IRFPA. The complex programmable logic device (CPLD) is applied into the system to increase its flexibility. With high reliability and precision, along with the integrated software and hardware environment, the system can test all kinds of ROICs.

Testing System Based on Virtual Instrument for Readout Circuit of Infrared Focal Plane Array

Readout integrated circuit(ROIC) is one of the most important components for hybrid-integrated infrared focal plane array(IRFPA). And it should be tested to ensure the product yield before bonding. This paper presents an on-wafer testing system based on Labview for ROIC of IRFPA. The quantitative measurement can be conducted after determining whether there is row crosstalk or not in this system. This low-cost system has the benefits of easy expansion, upgrading, and flexibility, and it has been employed in the testing of several kinds of IRFPA ROICs to measure the parameters of saturated output voltage, non-uniformity, dark noise and dynamic range, etc.

Automatic measurement of the working band of a digital attenuator based on virtual instrument

To measure the working band of a digital attenuator automatically,a program based on virtual instrument was carried out,using Agilent E8362B network analyzer as its measuring tool.In the program,the attenuation values can be automatically written into Excel table to form the frequency-attenuation curve.Finally,through analyzing the attenuation in different frequency,the best working band of the digital attenuator can be determined easily,and the whole process is automated.Compared with the traditional way of changing the measured parameters manually and recording the measured data one by one,the developed method in the paper can avoid the cumbersome manual operation and its possible errors to improve the measurement accuracy and efficiency.

Ventilator performance evaluation system based on virtual instruments

A virtual instrument system is proposed to test the performance parameters of local-ventilator installed under coal mines,which can do ventilator parameter acquisition automatically,as well as plot and analyze the ventilator performance curve.The whole system is designed using the virtual instrument technology combined with network technology based on Labview platform.Experimental results show that it can monitor and evaluate ventilator’s performance parameters automatically and efficiently,which provides critical information for ventilator safety under coal mine.

The engine performance LabVIEW virtual instrument test system design

This paper adopts American National Instruments (NI) Company’s LabVIEW and LabVIEW RT virtual instrument softwareplatform and lots of things for this engine performance LabVIEW virtual instrument test system, such as the matched NI PCI dataCollection Card, NI SCXI signal-adjusting instrument and NI compact FieldPoint (cFP) distributed I/O real time system hardware.This system has realized multi performances’parallel test; and it can complete load, torsional moment, rotate speed, power, pressureand temperature’s real time monitoring automatically according to user’s setting; and finally through TCP/IP protocol it realizes testdata’s teleshare and telecontrol that user put on the test system. This system has such character as short development period, highuse efficiency and low cost, at the same time it has strong extensibility and reusability, so it has very high applied cost.

Research on Construction Technology of Optical Radiation Measuring System Based on Virtual Instrument Technolo

Using virtual instrument technology, digital signal processing technology and traditional optical radiation measuring technology to construct optical radiation measuring system breaks the construction methods of traditional instruments. Signal processing, collection, control and process of measuring system are implemented by the software LabVIEW8.2. And they are integrated in a computer. The computer not only is data processing center, but also is instrument control center. While measuring, the user uses the mouse to operate the handles including knobs, switch and buttons of virtual instrument panel to select instrument functions and set various parameters, which realizes measuring optical radiation with different wave bands and different intensity. And the user can change insmament operation panel, modify system software, transform instrument function, and customize instrument parameters, which embodies the idea that the software is the instnnnent.

Study on Vibration Detection System of Wind-driven Generator based on Virtual Instrument

This study analyzes the structural characteristics of wind-driven generator,concludes its comment malfunctions and proposes effective methods by general fault analysis methods,so as to design online detection and fault diagnosis system of wind-driven generator in virtual instrument.This work will realize real-time detection,help engineers to proceed remote fault diagnosis,reduce maintenance time and increase production efficiency.This study is meaningful and practical to develop a fault diagnosis system for wind-driven generators,which shows professionalization of fault diagnosis system.

Application of Virtual Instrumentation in HL-2A DAPS

HL-2A DAPS is a large scale special data system for HL-2A tokamak . Technology of network, communication, data acquisition, data processing, real-time display, data management and systems management have been used in this system. With higher quality products and lower design costs, virtual instrumentation has been widely used in HL-2A DAPS. Vh-tual instrumentation combines mainstream commercial technologies, with flexible software and a wide variety of measurement and control hardware. It＇s easily to create user-defined systems that meet the exact application needs for the experiment.

Underground vibration signal detection and processing system based on LabWindows/CVI

In order to detect and process underground vibration signal, this paper presents a system with the combination of software and hardware. The hardware part consists of sensor, memory chips, USB, etc. , which is responsible for capturing original signals from sensors. The software part is a virtual oscilloscope based on LabWindows/CVI （C vitual instrument）, which not only has the functions of traditional oscilloscope but also can analyze and process vibration signals in special ways. The experimental results show that the designed system is stable, reliable and easy to be operated, which can meet practical requirements.

Measurement and control system for servo pressure pulse testing equipment

Servo pressure pulse testing equipment uses servo-hydraulic technology to build the model of hydraulic system. By improving measurement and control system, the equipment accomplishes signal acquisition, data processing and process con- trol. LabVIEW and programmable logic controller （PLC） are used to carry out the hardware configuration and software de- velopment. The system can communicate between LabVIEW and PLC by virtual instrumentation software architecture （VI- SA） and run automatically in accordance with setting commands. Therefore, accuracy and performance of the equipment are improved.

Performance evaluation methods and instrumentation for mine ventilation fans

Ventilation fans are one of the most important pieces of equipment in coal mines. Their performance plays an important role in the safety of staff and production. Given the actual requirements of coal mine production,we instituted a research project on the measurement methods of key performance parameters such as wind pressure,amount of ventilation and power. At the end a virtual instrument for mine ventilation fans performance evaluation was developed using a USB interface. The practical performance and analytical results of our experiments show that it is feasible,reliable and effective to use the proposed instrumentation for mine ventilation performance evaluation.

THEORY AND APPLICATION OF WAVELET ANALYSIS INSTRUMENT LIBRARY

Some new theory and algorithms on wavelet analysis are proposed, including continuous wavelet transform （CWT）, discrete wavelet transform （DWT）, wavelet package transform （WPT）, wavelet denosing and mother wavelet selection, etc. Using the component-based hierarchy mode, the platform for virtual instrument （VI） is constructed, and the functions such as data sampling, data analysis and data present, etc are provided. Subsequently, the wavelet analysis library is designed and developed. The library consists of expert system, experienced database, development platform and abundant wavelet analysis functional module, which together implement general and special wavelet analysis in the field of mechanical engineering, energy source, transportation and biomedicine, etc. Finally, the wavelet analysis virtual instrument library is applied to detect fault called engine knock. Experimental result indicates that the wavelet analysis virtual instrument library can efficiently solve the engineering problem such as detecting engine knock.