A demodulation algorithm for processing rotational inertia signals using a torsion pendulum method based on differentiation and resonance frequency analysis

Zhang, Lieshan; Wang, Meibao; Lin, Jianguo; Liu, Pu

doi:10.1088/1361-6501/abadbc

Cited by 4 publications

(4 citation statements)

References 24 publications

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“…The centre of gravity (CG) for the swing is investigated in Section 3.1 based on Equation (3). In a next step, an example model is investigated, which is part of a research project at FloWave.…”

Section: Centre Of Gravity (Cg)-examplementioning

confidence: 99%

“…The quality of the results is dependent on an accurate measurement of the distance between the centre of gravity and the pivot point. This approach is reduced to a one degree-of-freedom problem similar to a torsion pendulum method, which can be used to measure rotational inertia [2][3][4]. This approach is practical to conduct, measure and analyse the properties of rigid bodies.…”

Section: Introductionmentioning

confidence: 99%

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Accuracy Analysis of the Measurement of Centre of Gravity and Moment of Inertia with a Swing

et al. 2021

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Floating devices under wave and current loads are typically designed based on numerical methods followed by a validation with experimental investigations. This allows an independent check due to the comparison of two different modelling approaches based on different assumptions. At an early stage of the project, numerical simulations are based on theoretical (ideal) values of the centre of gravity (CG) and moment of inertia (MI). The building process of a scaled model results very often in a requested simplification of certain parts, which can influence the CG and also the MI of the scaled model. Knowing those discrepancies allows us to improve the comparability of both approaches but the measurement of those values is connected with either a higher uncertainty or a high level of effort. A significant improvement of such measurements can be reached by the deployment of a specific experimental set-up. This paper presents the classification of the newly designed swing with a high accuracy inertial inclinometer, which was verified by the marker-based motion capturing system. The achieved experiences are useful for the future use of the set-up as well as similar investigations. The comparison with the theoretical values for the swing as well as an example model showed very good agreements and a high accuracy of few millimetres for the CG and an error smaller 1% for MI.

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Section: Centre Of Gravity (Cg)-examplementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Accuracy Analysis of the Measurement of Centre of Gravity and Moment of Inertia with a Swing

et al. 2021

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“…Measurement standards solely exist for the mass and centre of gravity location [11,12]. Determining the inertia tensor necessitates special, complex, and costly dedicated test rigs [13][14][15]. Two distinct approaches are employed for measuring the mass properties of rigid bodies.…”

Section: Introductionmentioning

confidence: 99%

Mass, Centre of Gravity Location and Inertia Tensor of Electric Vehicles: Measured Data for Accurate Accident Reconstruction

Previati,

Mastinu,

Gobbi

2024

WEVJ

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Accurate accident reconstruction requires the knowledge of the mass properties of vehicles, namely the centre of gravity location, the mass and the inertia tensor. Such data are seldom available, especially in case of newly produced electric vehicles. In this paper, vehicle inertia measurements, performed at Politecnico di Milano, refer to a number of electric vehicles. In addition to the “simple” measurement of vehicle inertia, measured mass properties are analysed to derive the proper empirical formulae for the estimation of the centre of gravity height and the moments of inertia. Both internal combustion and electric vehicles are considered. Data show a significant difference in the mass properties of the two types of vehicles. The proposed formulae can be effectively employed to quickly obtain a reasonable estimation of the mass properties of any vehicle. The results show that electric vehicles are characterised by higher values of mass with respect to internal combustion vehicles, but they present a lower centre of gravity location and proportionally lower values of the moments of inertia.

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“…In an experiment, the object under test is generally set in motion in a certain way, and the measurement of rotational inertia is obtained from the mathematical relationship between motion characteristics and rotational inertia. The torsion vibration response method is a commonly used mechanical performance testing method in engineering [ 18 ], and different torsion vibration testing methods, including the multiple pendulum method [ 13 ], compound pendulum method [ 19 ], and torsion pendulum method [ 20 ], are often used for testing inertial parameters. Among them, the torsion pendulum method is currently the most accurate and reliable method for measuring rotational inertia and is widely used in the measurement of the rotational inertia of large-sized equipment [ 21 , 22 , 23 ].…”

Section: Introductionmentioning

confidence: 99%

Research on the Measurement Technology of Rotational Inertia of Rigid Body Based on the Principles of Monocular Vision and Torsion Pendulum

Chen

Zeng

et al. 2023

Sensors

Self Cite

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Damping is an important factor contributing to errors in the measurement of rotational inertia using the torsion pendulum method. Identifying the system damping allows for minimizing the measurement errors of rotational inertia, and accurate continuous sampling of torsional vibration angular displacement is the key to realizing system damping identification. To address this issue, this paper proposes a novel method for measuring the rotational inertia of rigid bodies based on monocular vision and the torsion pendulum method. In this study, a mathematical model of torsional oscillation under a linear damping condition is established, and an analytical relationship between the damping coefficient, torsional period, and measured rotational inertia is obtained. A high-speed industrial camera is used to continuously photograph the markers on a torsion vibration motion test bench. After several data processing steps, including image preprocessing, edge detection, and feature extraction, with the aid of a geometric model of the imaging system, the angular displacement of each frame of the image corresponding to the torsion vibration motion is calculated. From the characteristic points on the angular displacement curve, the period and amplitude modulation parameters of the torsion vibration motion can be obtained, and finally the rotational inertia of the load can be derived. The experimental results demonstrate that the proposed method and system described in this paper can achieve accurate measurements of the rotational inertia of objects. Within the range of 0–100 × 10−3 kg·m2, the standard deviation of the measurements is better than 0.90 × 10−4 kg·m2, and the absolute value of the measurement error is less than 2.00 × 10−4 kg·m2. Compared to conventional torsion pendulum methods, the proposed method effectively identifies damping using machine vision, thereby significantly reducing measurement errors caused by damping. The system has a simple structure, low cost, and promising prospects for practical applications.

show abstract

A demodulation algorithm for processing rotational inertia signals using a torsion pendulum method based on differentiation and resonance frequency analysis

Cited by 4 publications

References 24 publications

Accuracy Analysis of the Measurement of Centre of Gravity and Moment of Inertia with a Swing

Accuracy Analysis of the Measurement of Centre of Gravity and Moment of Inertia with a Swing

Mass, Centre of Gravity Location and Inertia Tensor of Electric Vehicles: Measured Data for Accurate Accident Reconstruction

Research on the Measurement Technology of Rotational Inertia of Rigid Body Based on the Principles of Monocular Vision and Torsion Pendulum

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