Order Tracking in Vibro-acoustic Measurements:A Novel Approach Eliminating the Tacho Probe

Herlufsen, H.; Hansen, Hans Konstantin

doi:10.4271/2005-01-2266

Cited by 18 publications

(19 citation statements)

References 3 publications

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“…In particular, it has been verified that the accelerometer signal spectrum shows a high energy content in correspondence of the revolution frequency (f R ) or one of its multiples, such as the blade frequency (f B ) [4,5]. In order to clarify this consideration, Figure 2 shows the frequency spectrum of the vibration signal acquired during Test 5, evaluated through the Short Time Fourier Transform algorithm.…”

Section: Turbocharger Speed Calculationmentioning

confidence: 98%

“…(3) This differential equation can be written in the crank angle frequency domain applying a Fourier expansion. Average values of the Fourier expansion applied to Equation (3) return the usual balance equation for the turbocharger assembly: (4) In this case, the effect of turbocharger speed fluctuations on η o (mechanical efficiency) is neglected, since the amplitude of speed fluctuations is very low with respect to turbocharger speed mean value. Taking into account the frequency domain transform of Equation (3) evaluated in correspondence of the combustion harmonic component (harmonic 4, that corresponds to engine order 2 for a 4 cylinders engine with evenly-spaced combustions) and considering that only turbine power will show significant order 2 fluctuations, due to the pulsating exhaust gas flow entering the turbine, it can be obtained: (5) Assuming that a proportional correlation between average power and pulsating power due to the flow exiting by each cylinder exists [11,12], it is possible to write: (6) In addition, since the only speed fluctuation of interest is the one corresponding to engine order 2 (harmonic 4), amplitude, i.e.…”

Section: Turbocharger Speed Fluctuations Estimationmentioning

confidence: 99%

“…Many works, carried out over the last years, demonstrate the feasibility of rotational speed calculation based on a proper processing of vibration [4] or acoustic emission [5] signals. The main limit of these methodologies consists in the fact that only turbocharger rotational speed mean value (evaluated over a complete revolution) can be estimated, while no information about the amplitude of speed fluctuations is provided.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Non-Intrusive Methodology for Estimation of Speed Fluctuations in Automotive Turbochargers under Unsteady Flow Conditions

Ponti¹,

Ravaglioli²,

Corti³

et al. 2014

SAE Int. J. Engines

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The optimization of turbocharging systems for automotive applications has become crucial in order to increase engine performance and meet the requirements for pollutant emissions and fuel consumption reduction. Unfortunately, performing an optimal turbocharging system control is very difficult, mainly due to the fact that the flow through compressor and turbine is highly unsteady, while only steady flow maps are usually provided by the manufacturer. For these reasons, one of the most important quantities to be used onboard for optimal turbocharger system control is the rotational speed fluctuation, since it provides information both on turbocharger operating point and on the energy of the unsteady flow in the intake and exhaust circuits.This work presents a methodology that allows determining the instantaneous turbocharger rotational speed through a proper frequency processing of the signal coming from one accelerometer mounted on the turbocharger compressor. Consequently, the developed algorithm can be used to determine both rotational speed mean value and the amplitude of speed fluctuations that are caused by unsteady flows. From this last evaluated quantity, it is also possible to obtain an estimation of power delivered by the turbine, that might be used for control and diagnostic purposes.The whole estimation algorithm has been developed and validated for a light duty turbocharged Diesel engine installed in a test cell at the University of Bologna. This paper reports the experimental layout used in this work and the accuracy obtained applying the speed fluctuations estimation procedure to the turbocharged Diesel engine under study.

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Section: Turbocharger Speed Calculationmentioning

confidence: 98%

Section: Turbocharger Speed Fluctuations Estimationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Non-Intrusive Methodology for Estimation of Speed Fluctuations in Automotive Turbochargers under Unsteady Flow Conditions

Ponti¹,

Ravaglioli²,

Corti³

et al. 2014

SAE Int. J. Engines

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show abstract

“…The authors in [8] emphasize that a typical technique to measure the fundamental frequency of rotary machines requires proximity probes or photo-sensors which can be hard task. In this work, mechanical vibration and/or acoustic signals are used to exact the fundamental frequency of an automotive passenger car.…”

Section: Spectrogram Approach: State Of the Artmentioning

confidence: 99%

Spectrogram Analysis: An Approach to Identify The Quadrotor Thrust Model

Brandão¹,

Pizetta²,

Pizziolo³

et al. 2018

Preprint

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Abstract:This paper deals with a non-contact method to identify the aerodynamic propeller parameters of the Parrot AR.Drone quadrotor. The experimental set consists in a camera recording the vehicle flights, the audio signal is extracted and is used a spectrogram analysis to estimates the propeller velocity. First, the aerial vehicle takes off and starts a hovering maneuver. The experiment is repeated with different additional masses attached to its rigid body. If the weight over the UAV increases/decreases, then the propeller must rotates faster/slower to produce a higher/lower thrust, and consequently, the sound frequency increases/decreases. Finally, this proposition is validated experimentally, and the estimated velocity is used to identify the quadrotor thrust parameters.

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“…This is not appropriate in this case as the initial and end values of a data block are important for accurate frequency estimation. For further details, refer to[2].…”

mentioning

confidence: 99%

Estimation of Instantaneous Speed for Rotating Systems: New Processing Techniques

Vemuri

Allemang

Phillips

2016

Rotating Machinery, Hybrid Test Methods, Vibro-Acoustics &Amp; Laser Vibrometry, Volume 8

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Table of Figures viii Nomenclature xiv vi 4.2 Iterative Improvements to the Procedure 4.3 Procedure for the Improved Bayesian Algorithm 4.4 Model with Two or More Dominant Frequencies 4.5 Smart Algorithm 4.6 Comparison to Spline Fit Estimate: 5. The Pulse Algorithm (nPA) 41 5.1 Need for a Better Instantaneous Speed Estimation Process 5.2 Analysis of the Cause for Fluctuations in the Instantaneous Speed Curve

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Order Tracking in Vibro-acoustic Measurements:A Novel Approach Eliminating the Tacho Probe

Cited by 18 publications

References 3 publications

Non-Intrusive Methodology for Estimation of Speed Fluctuations in Automotive Turbochargers under Unsteady Flow Conditions

Non-Intrusive Methodology for Estimation of Speed Fluctuations in Automotive Turbochargers under Unsteady Flow Conditions

Spectrogram Analysis: An Approach to Identify The Quadrotor Thrust Model

Estimation of Instantaneous Speed for Rotating Systems: New Processing Techniques

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