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Instrumentation and Measurement Technology Conference, 1993. IMTC/93. Conference Record., IEEE

Date 18-20 May 1993

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Displaying Results 1 - 25 of 158
  • Robot skills development using a laser range finder

    Publication Year: 1993 , Page(s): 448 - 452
    Cited by:  Papers (1)
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    One of the sensors being used to develop robot skills is a wrist-mounted laser ranger finder. This is an active sensor which projects a spot of laser light that is scanned across a surface measuring the range by triangulation. The scanning range finder and its calibration are described. Acquiring reliable and accurate data is only one step toward increased robot capabilities. Interpretation of the data, how the data affects the control loop, and how these steps can be combined to create a required functionality are addressed by a new computational paradigm called SKORP. Robot operations are described in terms of a sequence of robot skills, which may be reused in other operations. The objective is to develop a computational environment where the realtime systems programming using sensor data is separate from the application-oriented programming. The application level programming environment is iconic, and examples are shown of how the robot operation is specified at this level. The systems programmer develops the skills on a multiprocessor architecture. This level of the SKORP paradigm is exemplified by describing the development of a skill which uses the wrist-mounted range finder to follow an edge on an undulating surface while maintaining the orientation of the wrist-mounted range finder constant with respect to the edge in five degrees of freedom. View full abstract»

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  • 1993 IEEE Instrumentation and Measurement Technology Conference

    Publication Year: 1993
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    Freely Available from IEEE
  • Simultaneous hydrostatic pressure and temperature measurement employing a LP01-LP11 fiber-optic polarization-sensitive intermodal interferometer

    Publication Year: 1993 , Page(s): 426 - 429
    Cited by:  Papers (1)
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    The authors propose a polarization-sensitive LP01-LP 11 two-mode interferometer employing a highly birefringent fiber for the direct simultaneous measurement of high hydrostatic pressure and ambient temperature. The results show that the most suitable type of birefringent fiber for this type of two-parameter sensing is the bow-tie fiber, whereas elliptical-core and D-shaped fibers exhibit nonlinear dependence of their sensitivities. The results are found to be in agreement with a recently developed Müller-Stokes formalism describing polarization effects in the case of two-mode interference. Initial calibration of the two parameter simultaneous pressure-and-temperature sensor has also been performed up to 100 MPa using a primary pressure standard View full abstract»

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  • Coherence dependence of fiber-optic laser Doppler velocimeter output using self-mixing laser diode

    Publication Year: 1993 , Page(s): 420 - 425
    Cited by:  Papers (2)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (476 KB)  

    A new laser Doppler velocimeter (LDV) employing a self-mixing laser diode (SM-LD), which has a long optical fiber of 10 m to 1 km, as a light guide. This new LDV can measure a Doppler best signal with high signal to noise ratio in the range of 20-40 dB. The reason why the Doppler beat signal is obtained from a photodiode accommodated in the SM-LD having such a long fiber is attributed to the coherence length enhancement of the SM-LD, which extends to 400 m or more View full abstract»

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  • Accurate spectral estimation based on measurements with a distorted-timebase digitizer

    Publication Year: 1993 , Page(s): 699 - 704
    Cited by:  Papers (4)
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    To accurately measure amplitude and phase of the spectral components of a multispectral microwave signal an equivalent time broadband sampling oscilloscope with an appropriate triggering can be used. A method is described which allows an accurate estimation of the values of the spectral components of a signal, with significant timebase error present in a digitized sine wave. Once this error is characterized one complex function, called kernel, is calculated for each frequency component present in the signal. This kernel will be dependent on the timebase error and the set of frequencies. It is constructed so that the result of an inner product between kernel and measured signal equals the value of the spectral component with the associated frequency. These kernels are stored and used for calculating accurate spectral estimations of signals present at the scopes input port, by calculating the inner products between the different kernels and the measured signals. When properly applied the use of windowing techniques can improve accuracy View full abstract»

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  • CCD near infrared temperature imaging in the steel industry

    Publication Year: 1993 , Page(s): 299 - 303
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (368 KB)  

    The development of a charge coupled device CCD near infrared (NIR) temperature imaging technique is discussed. The authors describe the CCD NIR temperature imaging system configuration and the calibration approaches to achieve absolute temperature measurement. The CCD NIR sensor only measures relative temperatures. Therefore appropriate calibration methods are required to measure absolute temperature. Several successful applications of the CCD NIR imaging technique have been implemented in areas such as the coke ovens, sinter plant, hot plate and strip mill production lines. These steel industry applications are outlined View full abstract»

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  • Design of a very high resolution network analyser

    Publication Year: 1993 , Page(s): 470 - 475
    Cited by:  Papers (2)  |  Patents (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (540 KB)  

    A major characteristic of a network analyzer is its frequency resolution; i.e. the minimal distance between two adjacent frequency lines the analyzer can handle. The authors show how this frequency resolution can be enhanced. The frequency resolution can be improved either by decreasing the sampling frequency or increasing the number of time samples. The solution adopted is real-time interpolation in the generator and real-time subsampling in the acquisition unit. With this technique the generated output signal is computed in real-time starting from a small set of samples. This small set cannot contain enough information to cover the entire frequency band. However it is possible to put that narrow-band signal in any desired portion of the frequency band so that the instrument bandwidth is not reduced. Likewise, on the acquisition side the large amount of incoming samples is immediately decimated to a much smaller set and only this set has to be stored in memory. This also implies that during one measurement cycle only a fraction of the total bandwidth can be measured. The process of interpolation and subsampling is described, with the emphasis on the practical implementation choices that have to be made View full abstract»

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  • Applications of rare-earth-doped fibres

    Publication Year: 1993 , Page(s): 290 - 294
    Cited by:  Papers (1)  |  Patents (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (432 KB)  

    Rare-earth-doped fiber lasers and their applications are reviewed. Erbium-doped fiber lasers operating around 1.55 μm and thulium-doped fiber lasers operating around 1.9 μm are described. Mode-locking, Q-switching, wavelength tuning, and narrow and broad linewidth operation are discussed. Presented applications of fiber lasers include lidar, remote sensing, coherent detection, and fiber gyroscope sources View full abstract»

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  • A laser-interferometer measuring displacement with nanometer resolution

    Publication Year: 1993 , Page(s): 410 - 415
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    In material science there are certain classes of problems that require strain measurement over base lengths as small as 100 μm and still demand a resolution limit of about 10 microstrains. The author presents an interferometric strain sensor that is able to cope with that demand. The optical principle is given and the digital signal processing involved is detailed. Some experimental data for crack-tip opening displacement measurements on micro cracks and the measurement of thermal dilatation coefficients of copper are given View full abstract»

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  • Analysis of a constant voltage anemometer circuit

    Publication Year: 1993 , Page(s): 731 - 736
    Cited by:  Papers (9)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (376 KB)  

    A new circuit arrangement using an operational amplifier that maintains a constant voltage across a sensor connected between a node in the circuit and ground is described. The basic circuit consists of a T resistor network in the feedback of an operational amplifier where the sensor is connected in place of the center grounded element. The analysis of such a circuit arrangement is presented for a particular application to a hot-wire/film anemometer. An introduction is given to focus on the requirements of such a circuit to function as an anemometer, considering the hot-wire as a first order low-pass filter due to its thermal inertia. An innovative internal compensation method for the thermal inertia effects is presented which would extend the bandwidth. The expression for the overall bandwidth of such a circuit is derived with its sensitivity. An approach to extend the bandwidth even further using a composite amplifier configuration is presented. Experimental results showing excellent agreement with conventional approaches are presented. The advantage of the constant voltage operation in terms of insignificant cable capacitance effects and higher signal to noise ratio is discussed View full abstract»

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  • On-line measurement of fluid density using ultrasonic techniques

    Publication Year: 1993 , Page(s): 341 - 344
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (156 KB)  

    The possible use of ultrasonic techniques for the measurement of density for water and sulphuric acid is investigated. The relation of density, speed and acoustic impedance with temperature is determined. In an experiment, the relation between the speed of sound in H2SO4 and the specific gravity of H2SO 4 was examined. The results obtained matched those of the literature View full abstract»

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  • A monolithic six-port module for built-in-test applications

    Publication Year: 1993 , Page(s): 123 - 126
    Cited by:  Papers (2)
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    A fully monolithic six-port module is described. It includes a six-port junction, matched FET diode detectors, logarithmic amplifiers, and tunable Gunn-effect oscillators on a 3-mm × 3-mm GaAs die. On-chip temperature compensation of the detectors results in improved measurement reproducibility and increased dynamic range. In a reflectometer configuration, the monolithic six-port module (MSPM) demonstrates good agreement with National Institute of Standards and Technology (NIST) measurements on the same components. A built-in-test (BIT) demonstration of the MSPM allows the measurement of incident and reflected signals in an antenna feed while coupling less than 0.7% of the system power into the MSPM View full abstract»

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  • Fitting the exogenous model to measured data

    Publication Year: 1993 , Page(s): 366 - 370
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    The authors deal with the problem of fitting a statistical model to observations. The proposed approach relies on modeling data as drawn from an exogenous process, namely, a doubly stochastic random sequence, where a real non-negative process modulates a Gaussian, possibly complex, one. It is demonstrated that the problem of ascertaining to what extent the proposed model applies can be posed as a binary hypothesis testing problem; in particular, proper data processing leads to a distribution-free test statistic which is one and the same independent of the data distribution and correlation. The proposed procedure is validated where the operation characteristics of the test are evaluated with reference to a properly designed experimental setup View full abstract»

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  • Limited dynamic range of spectrum analysis due to roundoff errors of the FFT

    Publication Year: 1993 , Page(s): 47 - 50
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    Roundoff errors of the block-float fast Fourier transform (FFT) are treated. Special emphasis is given to the case when signals containing sine waves are analyzed. In the detection and analysis of sine waves, root-mean-square values and overall signal-to-noise ratios do not provide adequate information. An analysis of the maximum values is suggested, and the achievable dynamic range is given. It is shown that in contrast to the common understanding, the dynamic range does not significantly depend on the point number of the FFT, when the roundoff errors originate dominantly from the arithmetic roundings within the FFT View full abstract»

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  • Multifrequency binary measurement using frequency shift keyed symbols

    Publication Year: 1993 , Page(s): 360 - 365
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (456 KB)  

    A new approach to designing signals for multifrequency binary testing (MBT) depends on digital modulation, which uses shift keyed symbols. This allows a variety of ways in which the binary energy may be concentrated in arrays of dominant harmonics. Phase shift keyed (PSK) signals have been previously shown to give narrowband detail with a high spectral resolution. Frequency shift keyed (FSK) symbols with the aid of harmonic arrays are designed to obtain wideband frequency information. The power is concentrated in a lower and a higher harmonic array whose spacing may be adjusted by a wideband factor. New designs, which have both wideband and narrowband detail, are obtained by combining PSK and FSK symbols View full abstract»

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  • Charge amplifiers for piezoelectric sensors

    Publication Year: 1993 , Page(s): 465 - 468
    Cited by:  Papers (5)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (384 KB)  

    Research activities devoted to study and develop new piezoelectric tactile sensors for robotics show primary requirements of this class of sensor in terms of analog processing features. Charge amplifiers designed for this purpose are examined from the theoretical and experimental point of view showing performance data and limits in their application. A statistical approach has been adopted to validate experimental results obtained by testing a large number of devices. A new balanced circuit is proposed and analyzed to overcome the intrinsic disadvantages of the previous version of charge amplifiers. The experimental results obtained by testing the old and the new single-charge amplifier configuration show the benefits of adopting dedicated analog-processing structures for advanced piezoelectric sensors. Several considerations from the measurement and hybrid microelectronic point of view are presented View full abstract»

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  • High resolution distance measurement of laser-induced diffraction signals by digital signal processing

    Publication Year: 1993 , Page(s): 492 - 495
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (308 KB)  

    A diameter measurement method is presented offering an extremely good resolution, high signal-to-noise ratio and a high measuring rate. The measuring principle is based on the evaluation of the diffraction of a laser beam at fibers or thin wires for the determination of the diameter. The high accuracy of up to 0.1 μm resolution and the robustness are obtained by using digital signal processing and with the aid of a signal processor. Signal processing methods are discussed for a laser-induced diffraction signal by using the fast Fourier transform. The measuring method was implemented on a signal processor board placed in a PC. The diffraction signal is generated by a measuring head, consisting of a semiconductor laser collimator and charged coupled device line scan camera. The measuring head and evaluation unit are applicable as a complete measuring system for quality assurance in the production of fibers and thin wires. Experimental results are presented View full abstract»

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  • Real-time data-acquisition within a standard UNIX environment: Advantages of a divide-and-conquer strategy

    Publication Year: 1993 , Page(s): 687 - 689
    Cited by:  Papers (1)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (240 KB)  

    UNIX based workstations offer excellent tools for software development but are ill equipped for data-acquisition. Coupling of UNIX workstations with additional processors dedicated to measurement activities is feasible. In this way, using standard UNIX, real-time response can be achieved especially when little steering of the acquisition is necessary. Essential ingredients for this are an abstract description of the acquisition process and in most cases a dedicated processor for the actual acquisition. Some approaches are discussed and illustrated with setups used for among others proton induced X-ray emission measurements. Some realizations of virtual instruments are discussed View full abstract»

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  • Small and large signal device characterization made easier and faster with an integrated test system

    Publication Year: 1993 , Page(s): 6 - 9
    Cited by:  Papers (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (260 KB)  

    The authors describe a microwave test set that can be automatically reconfigured to perform linear and nonlinear characterization. Particular attention was devoted to speeding up the load pull contour tracking process. The test set measures S-parameters, power levels, gains, and harmonics up to 26 GHz. The software can set different loads randomly or by a special algorithm which automatically tracks power, gain, or efficiency contours. The test set was used to fully characterize several MESFETs up to 20 GHz. The system can be computer or manually driven and is particularly oriented to production tests View full abstract»

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  • A digital method for the identification of the source of distortion in electric power systems

    Publication Year: 1993 , Page(s): 658 - 662
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (488 KB)  

    The correct identification of the source of distortion in voltages and currents in the electric power systems is an important factor to attain an effective compensation of the non-active components of power. The authors illustrate a method based on the evaluation of the sign of the harmonic active powers that can identify the source of distortion in three-phase systems. The practical application of this method requires the accurate determination of the frequency-domain components of voltages and currents both in amplitude and phase. An instrument is also described based on digital signal processing techniques, specially realized to perform such a frequency-domain analysis in real-time and to indicate whether the current distortion is caused by load nonlinearity or by nonsinusoidal supply voltages. The results of some experimental work are reported and the instrument accuracy is discussed View full abstract»

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  • Unified approach to measurand reconstruction

    Publication Year: 1993 , Page(s): 403 - 408
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    Basic notions of measurement science are overviewed. A general scheme of measurement is proposed that emphasizes the key role of measurand reconstruction. The problems of measurand reconstruction are classified. Two classes being of particular importance in practical applications are identified and discussed in more detail. These are the nonlinear reconstruction of a scalar static measurand in the presence of a scalar influence quantity, and the linear reconstruction of a scalar dynamic measurand. Considerations of a tutorial and theoretical nature are illustrated with practical examples View full abstract»

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  • A capacitive sensor for the detection of humans in a robot cell

    Publication Year: 1993 , Page(s): 164 - 166
    Cited by:  Papers (10)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (304 KB)  

    To increase operator safety in robotic work cells, a capacitive sensor for detection of humans has been developed. The capacitive sensor has an antenna above the robot. The antenna covers the entire area of the robot cell. The floor of the robot cell is covered with an electrically insulated, conducting sheet. The sensor detects objects roughly in the shape of humans, placed between the antenna and the floor, and with an electrical conductivity similar to that of seawater. A person entering the cell causes a change of capacitance between the sheet and the antenna. This change is measured with a capacitance-voltage converter. The output voltage is used as a signal for human presence. The floor can be sectioned into several sheets separated from each other by guards. If the area is sectioned the sensor is not only able to give information about the presence of a person in the cell but also about the location of that person View full abstract»

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  • Source nonlinearity calibration using Volterra adaptive filters

    Publication Year: 1993 , Page(s): 663 - 667
    Cited by:  Papers (2)
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    A novel source nonlinearity calibration technique using Volterra adaptive filters is proposed. It provides a better result than the conventional methods with respect to speed, accuracy and memory size. The improvements are achieved at the cost of some additional computations, but this is not a significant problem in the context of current computational hardware. Most of the added computation can be done off-line. The authors explore the Volterra filters, a modified Volterra filter, and its use in nonlinearity calibrations. Simulation results using a practical case demonstrate the analytical results View full abstract»

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  • Solid state device for the measurement of light aircraft roll attitude

    Publication Year: 1993 , Page(s): 637 - 642
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (308 KB)  

    The authors describe a non-gyroscopic solid state device which provides an indication of the roll altitude of a light aircraft. The difference in altitude between the left and right wing tips is measured by commercially available solid state pressure sensors. For an average light aircraft with a wingspan of about 40 feet, the electrical signal corresponding to 1 degree in the roll attitude is of the order of 0.2 mV, but this measurement is also subject to ripple and drift noises of the same order of magnitude as the useful data. A microprocessor-based digital filter is described which cancels these effects and produces a reliable indication of roll attitude. The filtering philosophy uses an observation technique based on the dynamics of the lateral motion of the aircraft system. It is shown that even an approximate knowledge of the mathematical model results in effective filter operation and acceptable instrument fidelity View full abstract»

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  • An active load-pull set-up for the large signal characterization of highly mismatched microwave power transistors

    Publication Year: 1993 , Page(s): 2 - 5
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (260 KB)  

    The authors propose an active load-pull setup providing a solution to the problem of large signal measurement of highly mismatched microwave power transistors. The basic principle of the proposed measurement technique consists of using an appropriate mismatched power source to drive the output port of the device under test (DUT). It is possible to synthesize any highly mismatched load by using a classical active load-pull setup, but large incident power waves driving the output port of the DUT are required. If the phase of the injected power wave at the transistor output port is not properly controlled, the component may be damaged. The active load pull technique presented overcomes these limitations. A medium power silicon bipolar transistor was characterized at 1.8 GHz. A power silicon transistor was also characterized at 1.7 GHz under Class A operating conditions. Results are shown View full abstract»

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