Dynamic calibration uncertainty of three-axis low frequency accelerometers

Self Cite

Abstract. Two alternative experimental procedures for the calibration of tri-axial accelerometers have been compared with traditional methods, performed according the procedures stated in the standard ISO 16063-21. Standard calibration is carried out by comparison with a laser Doppler vibrometer (LDV), used as a primary reference transducer. The main sensitivities have been investigated and, where applicable, also transverse ones. Many aspects have been evaluated: the hypotheses about transverse sensitivities, the simplicity of the procedure, the number of measurements needed, and the effect of typology of transducer, depending on electrical and geometrical contributions. Two different accelerometers have been tested, a piezo-electric accelerometer and a capacitive MEMS accelerometer. A low-frequency range of vibration has been investigated, 3 and 6 Hz, with amplitude of acceleration ranging from 2 to 20 ms−2. A satisfactory reproducibility of methods has been verified, with percentage differences less than 2.5 %. Anyway, pros and cons of each method are also discussed with reference to their possible use for easy and quick calibration of low-cost tri-axial accelerometers.

Section: Methodsmentioning

confidence: 99%

“…The second one, Method 2 (Schiavi et al, 2015), allows us to determine the three main sensitivities, simultaneously. The last one (Method 3;D'Emilia et al ,2015D'Emilia et al , , 2016a gives the possibility of obtaining the main sensitivities, transverse sensitivities and offset terms. In Sect.…”

Section: Introductionmentioning

confidence: 99%

Calibration of tri-axial MEMS accelerometers in the low-frequency range – Part 1: comparison among methods

D’Emilia

Gaspari

Mazzoleni

et al. 2018

Self Cite

“…Method 3 (D'Emilia et al, 2015(D'Emilia et al, , 2016a is based on the following model, describing the relation between the input accelerations and the output signals as in Eq. 7:…”

Section: Methodsmentioning

confidence: 99%

Calibration of tri-axial MEMS accelerometers in the low-frequency range – Part 2: Uncertainty assessment

D’Emilia

Gaspari

Mazzoleni

et al. 2018

Self Cite

Abstract. A comparison among three methods for the calibration of tri-axial accelerometers, in particular MEMS, is presented in this paper, paying attention to the uncertainty assessment of each method. The first method is performed according to the ISO 16063 standards. Two innovative methods are analysed, both suitable for in-field application. The effects on the whole uncertainty of the following aspects have been evaluated: the test bench performances in realizing the reference motion, the vibration reference sensor, the geometrical parameters and the data processing techniques. The uncertainty contributions due to the offset and the transverse sensitivity are also studied, by calibrating two different types of accelerometers, a piezoelectric one and a capacitive one, to check their effect on the accuracy of the methods under comparison. The reproducibility of methods is demonstrated. Relative uncertainty of methods ranges from 3 to 5 %, depending on the complexity of the model and of the requested operations. The results appear promising for low-cost calibration of new tri-axial accelerometers of MEMS type.

“…Unfortunately this technique furnishes local information only on discrete points. Moreover, the measurement volume depends on the strain gauge dimensions, and often it is not lower than 1 mm (D'Emilia et al, 2015;Speranzini et al, 2016).…”

Section: Introductionmentioning

confidence: 99%

TSA infrared measurements for stress distribution on car elements

Marsili

Rossi

2017

Abstract. Because of the continuous evolution of the market in terms of quality and performance, the car production industry is being subjected to more and more pressing technological challenges. In this framework the use of an advanced measurement technique such as thermoelasticity allows the engineers to have a fast and reliable tool for experimental investigation, optimization and validation of the finite element method (FEM) of those critical parts, such as parts of car-frame tables (Marsili and Garinei, 2013;Ju et al., 1997). In this work it is shown how the thermoelastic measurement technique can be used to optimize a Ferrari car frame, as a method of experimental investigation and as a technique of validation of numerical models.The measurement technique developed for this purpose is described together with the calibration method used in the test benches normally used for fatigue testing and qualification of this car's components. The results obtained show a very good agreement with FEM models and also the possibility of experimentally identifying the concentration levels of stress in critical parts with a very high spatial resolution and testing the effective geometry and material structure.