skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Accuracy improvement in a calibration test bench for accelerometers by a vision system

Abstract

A procedure is described in this paper for the accuracy improvement of calibration of low-cost accelerometers in a prototype rotary test bench, driven by a brushless servo-motor and operating in a low frequency range of vibrations (0 to 5 Hz). Vibration measurements by a vision system based on a low frequency camera have been carried out, in order to reduce the uncertainty of the real acceleration evaluation at the installation point of the sensor to be calibrated. A preliminary test device has been realized and operated in order to evaluate the metrological performances of the vision system, showing a satisfactory behavior if the uncertainty measurement is taken into account. A combination of suitable settings of the control parameters of the motion control system and of the information gained by the vision system allowed to fit the information about the reference acceleration at the installation point to the needs of the procedure for static and dynamic calibration of three-axis accelerometers.

Authors:
; ; ;  [1]
  1. University of L’Aquila, Department of Industrial and Information Engineering and Economics (DIIIE), via G. Gronchi, 18, 67100 L’Aquila (Italy)
Publication Date:
OSTI Identifier:
22608645
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 1740; Journal Issue: 1; Conference: 12. international A.I.VE.LA. Conference on vibration measurements by laser and noncontact techniques: Advances and applications, Ancona (Italy), 29 Jun - 1 Jul 2016; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ACCELERATION; ACCELEROMETERS; ACCURACY; CALIBRATION; CAMERAS; CONTROL SYSTEMS; EQUIPMENT; EVALUATION; FREQUENCY RANGE; GAIN; INSTALLATION; PERFORMANCE; SENSORS

Citation Formats

D’Emilia, Giulio, E-mail: giulio.demilia@univaq.it, Di Gasbarro, David, E-mail: david.digasbarro@graduate.univaq.it, Gaspari, Antonella, E-mail: antonella.gaspari@graduate.univaq.it, and Natale, Emanuela, E-mail: emanuela.natale@univaq.it. Accuracy improvement in a calibration test bench for accelerometers by a vision system. United States: N. p., 2016. Web. doi:10.1063/1.4952690.
D’Emilia, Giulio, E-mail: giulio.demilia@univaq.it, Di Gasbarro, David, E-mail: david.digasbarro@graduate.univaq.it, Gaspari, Antonella, E-mail: antonella.gaspari@graduate.univaq.it, & Natale, Emanuela, E-mail: emanuela.natale@univaq.it. Accuracy improvement in a calibration test bench for accelerometers by a vision system. United States. doi:10.1063/1.4952690.
D’Emilia, Giulio, E-mail: giulio.demilia@univaq.it, Di Gasbarro, David, E-mail: david.digasbarro@graduate.univaq.it, Gaspari, Antonella, E-mail: antonella.gaspari@graduate.univaq.it, and Natale, Emanuela, E-mail: emanuela.natale@univaq.it. Tue . "Accuracy improvement in a calibration test bench for accelerometers by a vision system". United States. doi:10.1063/1.4952690.
@article{osti_22608645,
title = {Accuracy improvement in a calibration test bench for accelerometers by a vision system},
author = {D’Emilia, Giulio, E-mail: giulio.demilia@univaq.it and Di Gasbarro, David, E-mail: david.digasbarro@graduate.univaq.it and Gaspari, Antonella, E-mail: antonella.gaspari@graduate.univaq.it and Natale, Emanuela, E-mail: emanuela.natale@univaq.it},
abstractNote = {A procedure is described in this paper for the accuracy improvement of calibration of low-cost accelerometers in a prototype rotary test bench, driven by a brushless servo-motor and operating in a low frequency range of vibrations (0 to 5 Hz). Vibration measurements by a vision system based on a low frequency camera have been carried out, in order to reduce the uncertainty of the real acceleration evaluation at the installation point of the sensor to be calibrated. A preliminary test device has been realized and operated in order to evaluate the metrological performances of the vision system, showing a satisfactory behavior if the uncertainty measurement is taken into account. A combination of suitable settings of the control parameters of the motion control system and of the information gained by the vision system allowed to fit the information about the reference acceleration at the installation point to the needs of the procedure for static and dynamic calibration of three-axis accelerometers.},
doi = {10.1063/1.4952690},
journal = {AIP Conference Proceedings},
number = 1,
volume = 1740,
place = {United States},
year = {Tue Jun 28 00:00:00 EDT 2016},
month = {Tue Jun 28 00:00:00 EDT 2016}
}
  • This work presents the results of the design study, investigations of the features and a calibration of double-slit ion energy analyzer prototype at the test-bench in IPP NSC KIPT, Kharkov, Ukraine, with beam energy up to 10 keV. Hitherto obtained accuracy for both analyzer slits is {delta}G-2x10{sup -3} and {delta}F-3x10{sup -3}, which is limited by the existing step motor accuracy 0.1 mm for entrance slits moving. The presented study work is considered as the first step to the multi-slit analyzer elaboration.
  • Image-guided radiotherapy using a three-dimensional (3D) camera as the on-board surface imaging system requires precise and accurate registration of the 3D surface images in the treatment machine coordinate system. Two simple calibration methods, an analytical solution as three-point matching and a least-squares estimation method as multipoint registration, were introduced to correlate the stereo-vision surface imaging frame with the machine coordinate system. Both types of calibrations utilized 3D surface images of a calibration template placed on the top of the treatment couch. Image transformational parameters were derived from corresponding 3D marked points on the surface images to their given coordinates inmore » the treatment room coordinate system. Our experimental results demonstrated that both methods had provided the desired calibration accuracy of 0.5 mm. The multipoint registration method is more robust particularly for noisy 3D surface images. Both calibration methods have been used as our weekly QA tools for a 3D image-guided radiotherapy system.« less
  • The insulating materials and insulation distance of electrical apparatus are selected based on their life time of practical use. Estimation of this life time and evaluation of the reliability generally require a testing method with high accuracy, efficiency and adaptability. As an evaluation test for the insulation deterioration on the surface of the insulating materials due to electrical energy and moistened dust, the tracking test method has been prescribed. There are still many problems concerning the reliability of the test, including the considerable scattering of test data. For this reason, the following aspects have been studied: (1) Scintillant discharge ormore » ignition phenomena; (2) Tracking phenomena and actual packing conditions; and (3) Causes and improvement of the scattering of test data. Experiments have been performed concerning the differences between the IEC recommended method and a revised method. As a result, a method has been found which would increase the accuracy of the tracking test by the IEC revised method and would make it possible for evaluation in conformity with practice.« less
  • A hierarchical model calibration and validation is proposed for quantifying the confidence level of mass transfer prediction using a computational fluid dynamics (CFD) model, where the solvent-based carbon dioxide (CO2) capture is simulated and simulation results are compared to the parallel bench-scale experimental data. Two unit problems with increasing level of complexity are proposed to breakdown the complex physical/chemical processes of solvent-based CO2 capture into relatively simpler problems to separate the effects of physical transport and chemical reaction. This paper focuses on the calibration and validation of the first unit problem, i.e. the CO2 mass transfer across a falling ethanolaminemore » (MEA) film in absence of chemical reaction. This problem is investigated both experimentally and numerically using nitrous oxide (N2O) as a surrogate for CO2. To capture the motion of gas-liquid interface, a volume of fluid method is employed together with a one-fluid formulation to compute the mass transfer between the two phases. Bench-scale parallel experiments are designed and conducted to validate and calibrate the CFD models using a general Bayesian calibration. Two important transport parameters, e.g. Henry’s constant and gas diffusivity, are calibrated to produce the posterior distributions, which will be used as the input for the second unit problem to address the chemical adsorption of CO2 across the MEA falling film, where both mass transfer and chemical reaction are involved.« less
  • The first part of this paper (Part 1) presents a numerical model for non-reactive physical mass transfer across a wetted wall column (WWC). In Part 2, we improved the existing computational fluid dynamics (CFD) model to simulate chemical absorption occurring in a WWC as a bench-scale study of solvent-based carbon dioxide (CO2) capture. To generate data for WWC model validation, CO2 mass transfer across a monoethanolamine (MEA) solvent was first measured on a WWC experimental apparatus. The numerical model developed in this work has the ability to account for both chemical absorption and desorption of CO2 in MEA. In addition,more » the overall mass transfer coefficient predicted using traditional/empirical correlations is conducted and compared with CFD prediction results for both steady and wavy falling films. A Bayesian statistical calibration algorithm is adopted to calibrate the reaction rate constants in chemical absorption/desorption of CO2 across a falling film of MEA. The posterior distributions of the two transport properties, i.e., Henry’s constant and gas diffusivity in the non-reacting nitrous oxide (N2O)/MEA system obtained from Part 1 of this study, serves as priors for the calibration of CO2 reaction rate constants after using the N2O/CO2 analogy method. The calibrated model can be used to predict the CO2 mass transfer in a WWC for a wider range of operating conditions.« less