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![Biomechanical human body model showing the resonance frequencies of individual organs [5]](publication/336820094/figure/fig5/AS:818069056270337@1572054270141/Biomechanical-human-body-model-showing-the-resonance-frequencies-of-individual-organs-5.png)
Source publication
Purpose
The comfort of lift passengers has a significant effect on their general health condition as well as stress levels during travel. This study reports the results of vibration measurements taken during travel in a passenger lift.
Methods
Vibration signals were analyzed by the empirical mode decomposition method and the Hilbert transform.
Re...
Contexts in source publication
Context 1
... with a thickness of 20 mm. The walls of the cabin were made of sheet metal with a thickness of 1.2 mm, and they could generate additional vibration induced by the cabin frame. It can be observed that in subsequent mode modes the periodograms are centered around individual dominant frequencies. Values comprising a range of frequencies listed in Fig. 11 can be observed in the modes (m#4-m#6) (Table ...
Context 2
... the above analysis for passenger comfort assessment, it is worth drawing attention to the modes m#4, m#5 and m#6. The dominant frequencies in these modes may be particularly undesired for lift passengers due to the fact that they correspond to the resonance frequencies of many human body organs, as shown in Fig. ...
Context 3
... 5 m and 1.3 Hz (mod #13 in the ACC signal recorded on outside the cabin) probably related to the diameter of the rope guide wheels (wheel diameter 240 mm, diameter of the rope section 6.5 mm, number of ropes 10 pcs). These frequencies have values below the lower thresholds of harmful ranges for parts of the human body (minimum value is 2 Hz in Fig. 11). However, the disclosed relations may be used for changes in the elevator construction and elevator control system. Additional it may also indicate elements requiring additional inspection, such as guide wheels, to detect any irregularities ...
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Citations
... The vibration of the elevator cabin significantly affects the health condition as well as the stress level of the pupils during travel. The study in [13] measured and reported the results of vibration measurements taken during travel in a passenger elevator. There are guidelines on the possible effects of vibration on health, comfort, cognition, and motion sickness [14][15][16]. ...
... This was the main reason why a methodology was proposed in 2019 [21] to study the impact of vibrations on the drivers of e-scooters to evaluate whether, to what degree and under what conditions the vibrations we receive from these new means of transport influence our comfort and possibly our health, following the UNE-2631 standard [22]. Although there are numerous studies of comfort on other types of vehicles [23][24][25][26][27][28][29], nothing had been published about the need to study vibrations in e-scooters. ...
E-scooter vibrations are a problem recently studied. Theoretical models based on dynamic simulations and also real measurements have confirmed the high impact of e-scooter vibrations on driver comfort and health. Some authors recommend improving e-scooter damping systems, including tyres. However, it has not been suggested nor has any research been published studying how to improve e-scooter frame design for reducing driver vibrations and improving comfort. In this paper, we have modelled a real e-scooter to have a reference. Then, we have developed a multibody dynamic model for running dynamic simulations studying the influence of mass geometry parameters of the e-scooter frame (mass, centre of gravity and inertia moment). Acceleration results have been analysed based on the UNE-2631 standard for obtaining comfort values. Based on results, a qualitative e-scooter frame design guide for mitigating vibrations and increasing the comfort of e-scooter driver has been developed. Some application cases have been running on the multibody dynamic simulation model, finding improvements of comfort levels higher than 9% in comparison with the e-scooter reference model. The dynamic model has been qualitatively validated from real measurements. In addition, a basic sensor proposal and comfort colour scale is proposed for giving feedback to e-scooter drivers.
... Previous research has shown that slight vibration generally will not affect the safety and health of passengers. However, when the amplitude reaches a certain value, it will trigger the resonance phenomenon of the organs of passengers, which results in irreversible damage to their health [4]. Additionally, the human body has a sensitive range for cabin vibrations, which is 4-8 Hz vertically and 1-2 Hz horizontally with a higher sensitivity [5]. ...
Aiming at the problems of inefficient mitigation of the lateral vibration of high-speed elevator cars, which results in low riding comfort, this paper introduces the electromagnetic active rolling guide shoes and incorporates the sky-hook damping control strategy into the high-speed elevator structure. On this basis, it adopts an optimization algorithm based on Sparrow Search Algorithm (SSA) to adjust the parameters of the lateral vibration controller, thereby reducing the amplitude of the lateral vibration and controlling it within the human comfort range. Specifically, this paper first incorporates electromagnetic active rolling guide shoes into the vibration reduction device of the high-speed elevator car. Based on the motion characteristics of lateral vibration, a mathematical model is established in which the sky-hook damping control strategy is introduced. Then, a simulation model is built, and the damping parameters of the controller are optimized using the SSA, resulting in effective control of the lateral vibration amplitude of the high-speed elevator car. Simulations demonstrate that the lateral vibration control model of the high-speed elevator car, optimized by SSA, achieves lower amplitudes within the frequency range of 1–2 Hz compared to the results obtained by the Genetic Algorithm (GA), demonstrating the effectiveness of SSA in optimizing the damping parameters of the car controller. Finally, the simulation results are compared with the measured data, and the research findings indicate that the proposed method for lateral vibration control of the car can effectively suppress the lateral vibration amplitude.
... The elevator has been a major transportation tool to reach different locations of buildings in the modern cities (Szydło et al. 2020). The stability and safety of elevators is extremely related to elevator vibration status during the elevator operation (Feng et al. 2009;Zhang et al. 2019). ...
Collecting data such vibration signal or others from elevators is crucial for a regular maintenance or emergency repair in industry. However, traditional methods for data transmission through compression and decompression process usually require large input data arrays to be assigned. Therefore, a long computational time is unavoidable so that it may affect system performance efficiency significantly. Therefore, an elevator vibration and loading data collection system was developed using simple compression encoding mechanism. First, in Data Acquisition Unit, the signal-acquiring microprocessor is used for data acquisition through Inter-Integrated Circuit (I²C) bus. Second, in Data Storage Unit, the collected data from the signal-acquiring microprocessor is compressed and transmitted to the signal-processing microprocessor. Third, in Monitor Unit, the elevator analysis tool is developed to analyze the vibration data, which can be viewed directly from APP. Experimental results demonstrated that the restored data are consistent with the results measured from the standard instrument. The proposed hexadecimal compression process can make the data transmission mechanism simple, but two times faster than that using traditional way without compression. Consequently, the demanded memory capacity for signal transmission can be therefore reduced considerably.
... Normally, the level of vibrations of the elevator will increase gradually along the time of use, which is caused by the failed moving parts (tracker, hoist rope, and driving machine), and the damping parts being aging. Therefore, checking the vibration of the elevator is an important technical issue that needs to be carried out in order to maintain, repair, and prevent dangerous damage from the elevator [1]- [3]. Measuring the vibration of elevators is a rather complicated technical problem, an international standard ISO 18738-1:2012 (measurement of ride quality-Part 1: Lifts (elevators)) [4] has been established to help supports vibration and noise measurement methods. ...
span lang="EN-US">This paper presents a design of soft-gauge using the low-cost triple-axis accelerometer MMA7361L and LabVIEW software for the purpose of elevator vibration analysis with accuracy according to national standards. The 3-dimensional vibration signals measured and collected respectively by MMA7361L and NI USB6009 are fed into a soft-gauge programmed on LabVIEW to filter, then the fast Fourier transform (FFT) is applied to determine the power spectral density (PSD) and spectrogram of vibrations of filtered vibration signals. The soft-gauge also allows real-time 3-dimensional vibration data to be recorded, this data is used for analyzing later by another professional data software. Practical test results applied for the elevator of the DONGA Plaza building show quite good vibration analysis. Class 1.5 accuracy of the soft-gauge can be obtained by experimental test. This is a fairly cost-effective and inexpensive application that can be made in conditions with limited funds that cannot afford expensive accelerometers in the training of vibration measurement and analysis in high schools and vocational schools in developing countries, like Vietnam.</span
... Recently, the analysis of vibration signals has been widely used for diagnostic purposes of various engine units and systems, as well as other vehicle systems, e.g., gearbox or suspension. Many researchers use methods such as the Fourier transform and the wavelet transform [25][26][27], and Hilbert transform [28][29][30] or neural networks [31] for fault detection and operational parameters in rotating systems. Noteworthy are the papers in which the authors diagnosed fuel supply systems using vibration signals [21; 32] and charge exchange in the combustion chamber [33; 34]. ...
... Their mechanical design and the growing usage of e-scooters make it necessary to analyze the possible effects of the vibrations transmitted to the driver. There are several investigations about this topic for other means of transport [20][21][22][23][24][25][26]. ...
Background: Micro-mobility provides a solution for last mile problem and e-scooter sharing systems are one of the most heavily adopted micro-mobility services. The increasing usages of e-scooters make it necessary to analyze the possible effects of the vibrations transmitted to the drivers.
Purpose: This research has studied for the first time the e-scooter vibrations effects on drivers comfort and health for the actual range of circulation speeds, that can exceed 25 km/h.
Methods: Based on experimental measured stiffness of two different e-scooter wheels and Multibody dynamic simulations, several statistical models have been obtained following the standard UNE2631.
Results: The results show that for a common e-scooter and a road profile with a very good-good roughness level, a velocity of 16 km/h starts to be uncomfortable and for 23 km/h could be harmful for health, for short trip durations. Derived from the statistical models, a new way of measuring the roughness has been proposed and that will be one of the future works to adjust and validate it.
Conclusion: E-scooter suspension systems (front suspension and wheels) must be improved under human comfort and health point of view. Furthermore, results suggest the necessity of study the vibrations effects on real e-scooters due to the maximum speed they can reach is greater than 25 km/h.
... However, the elevators of HRB operated at a high-speed cause problems such as changes in atmospheric pressure inside and outside a lift car, noise, and vibration [4][5][6][7][8][9][10][11][12][13]. In particular, elevator noise and vibration (ENV) cause both mental anxiety for passengers and a consistent negative effect on promoting a comfortable residential area close to the elevator shaft [11,[14][15][16][17][18][19][20][21]. ...
... However, the elevators of HRB operated at a high-speed cause problems such as changes in atmospheric pressure inside and outside a lift car, noise, and vibration [4][5][6][7][8][9][10][11][12][13]. In particular, elevator noise and vibration (ENV) cause both mental anxiety for passengers and a consistent negative effect on promoting a comfortable residential area close to the elevator shaft [11,[14][15][16][17][18][19][20][21]. To secure a sustainable living environment, the impacts can be significant issues related to sound quality, sleeping conditions, and enjoyment within residences [14,[16][17][18][19][20][22][23][24][25]. ...
... This study is precisely processed on HRBs with >12 floors and elevators at a speed of >90 m/min. The change of air pressure, noise, and vibration generated while HRB elevators are being operated cause passengers to be discomforted and has a negative effect on the residential environment of nearby residents [4,8,[11][12][13]. As per the building code of many countries, the characteristic noise level, because of a life within an apartment building, should not exceed 30 dB(A) in any bedroom or living room of apartments [15,[43][44][45]. ...
In high-rise residential buildings (HRBs), elevators run at a high speed, which causes problems such as change of atmospheric pressure, noise, and vibration. Elevator noise and vibration (ENV) of HRBs causes both mental anxiety and a consistently negative effect for promoting a comfortable residential area. Therefore, a solution for alleviating the ENV of HRBs is essential. To date, studies related to ENV have been mostly conducted in the approach of mechanical and electric aspects. There have been few cases conducted from the perspective of construction management (CM), which integrates design and construction. Therefore, the aim of this study is to propose CM solutions to mitigate the ENV of HRB. For this study, the CM solution is presented after identifying the ENV problems of HRBs through documented research and case measurement. By measuring the noise of HRB that the solution was applied to, the noise level, especially in a range of >125 Hz, was extensively reduced. The result of this study will be used as sustainable guidelines that alleviate ENV problems in the process of design and construction of HRB elevators. It is expected that studies for improving ENV problems that occur in high-rise elevators will increase on the basis of the results of this study.
... By decomposing the complex time series data into intrinsic mode functions (IMFs) with trend characteristics and estimating the amplitude and frequency of IMFs, HHT can be used to obtain more information about the features of the time series fluctuations than basic statistics such as the mean, standard deviation, and skewness [26]. Because of the advantages of HHT in analyzing non-stationary and non-linear time series data, this method is widely used in various professional fields, such as geophysics, health monitoring, ocean engineering, chemical engineering, and financial analysis [27][28][29][30][31][32][33]. HHT has also been thoroughly applied in atmospheric turbulence and meteorological analyses [34,35]. ...
To analyze the time–frequency characteristics of the particulate matter (PM10) concentration, data series measured at dry bulk ports were used to determine the contribution of various factors during different periods to the PM10 concentration level so as to support the formulation of air quality improvement plans around port areas. In this study, the Hilbert–Huang transform (HHT) method was used to analyze the time–frequency characteristics of the PM10 concentration data series measured at three different sites at the Xinglong Port of Zhenjiang, China, over three months. The HHT method consists of two main stages, namely, empirical mode decomposition (EMD) and Hilbert spectrum analysis (HSA), where the EMD technique is used to pre-process the HSA in order to determine the intrinsic mode function (IMF) components of the raw data series. The results show that the periods of the IMF components exhibit significant differences, and the short-period IMF component provides a modest contribution to all IMF components. Using HSA technology for these IMF components, we discovered that the variations in the amplitude of the PM10 concentration over time and frequency are discrete, and the range of this variation is mainly concentrated in the low-frequency band. We inferred that long-term influencing factors determine the PM10 concentration level in the port, and short-term influencing factors determine the difference in concentration data at different sites. Therefore, when formulating PM10 emission mitigation strategies, targeted measures must be implemented according to the period of the different influencing factors. The results of this study can help guide recommendations for port authorities when formulating the optimal layout of measurement devices.
