Equal comfort contours for whole body vertical, pulsed sinusoidal vibration

Jones, A.J.; Saunders, D.J.

doi:10.1016/0022-460x(72)90785-7

Cited by 37 publications

(9 citation statements)

References 5 publications

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“…For a subjective magnitude of 100, greatest sensitivity (i.e., where the acceleration required to cause a given level of discomfort is least) was at 5 Hz, consistent with previous studies using a variety of psychophysical methods for evaluating vibration discomfort (e.g., Dupuis et al, 1972;Jones and Saunders, 1972;Griffin, 1976;Griffin et al, 1982;Corbridge and Griffin, 1986;Morioka and Griffin, 2006a;Zhou and Griffin, 2014b). These studies investigated various ranges of vibration magnitude, vibration frequency, and durations of vibration, but the contours have broadly similar shapes, with the exception of the reduced sensitivity to higher frequencies in the studies reported by Dupuis et al (1972) and Jones and Saunders (1972) (see Figure 10 in Zhou and Griffin, 2014b).…”

Section: In Terms Of Unweighted Vdvsupporting

confidence: 87%

Frequency-dependence of discomfort caused by vibration and mechanical shocks

2018

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The frequency content of a mechanical shock is not confined to its fundamental frequency, so it was hypothesised that the frequency-dependence of discomfort caused by shocks with defined fundamental frequencies will differ from the frequency-dependence of sinusoidal vibration. Subjects experienced vertical vibration and vertical shocks with fundamental frequencies from 0.5 to 16 Hz and magnitudes from ±0.7 to ±9.5 ms. The rate of growth of discomfort with increasing magnitude of motion decreased with increasing frequency of both motions, so the frequency-dependence of discomfort varied with the magnitudes of both motions and no single frequency weighting will be ideal for all magnitudes. At the frequencies of sinusoidal vibration producing greatest discomfort (4-16 Hz), shocks produced less discomfort than vibration with same peak acceleration or unweighted vibration dose value. Frequency-weighted vibration dose values provided the best predictions of the discomfort caused by different frequencies and magnitudes of vibration and shock. Practitioner Summary: Human responses to vibration and shock vary according to the frequency content of the motion. The ideal frequency weighting depends on the magnitude of the motion. Standardised frequency-weighted vibration dose values estimate discomfort caused by vibration and shock but for motions containing very low frequencies the filtering is not optimum.

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Section: In Terms Of Unweighted Vdvsupporting

confidence: 87%

Frequency-dependence of discomfort caused by vibration and mechanical shocks

2018

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“…In the design stage of the vehicle development process when the real vehicle is not available, simulation is the only approach for the vehicle ride quality estimation [22]. Conventionally, ride quality was estimated by calculating jerk, acceleration, and velocity responses separately and applying each in the appropriate frequency interval [23]. Although there is still a great deal of controversy over which variables are most important in the effort on ride rating, many investigators have described vibration criteria in terms of acceleration amplitude as a function of frequency [24][25][26].…”

Section: Vehicle Ride Comfort Evaluation Based On Human Sensitivitymentioning

confidence: 99%

Genetic optimization of a fuzzy active suspension system based on human sensitivity to the transmitted vibrations

Montazeri-Gh

Soleymani

2008

Proceedings of the Institution of Mechanical Engineers, Part D:

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Optimization of a vehicle fuzzy active suspension (AS) controller was previously performed on the basis of the amplitude of transmitted vibrations to the body. However, ride comfort depends strongly on the human sensitivity, which is a function of not only the amplitude but also the frequency contents of the transmitted vibrations. In this paper, genetic optimization of a fuzzy AS system based on the human sensitivity to the transmitted vibrations is presented. For this purpose, a fuzzy logic controller (FLC) is initially proposed for the AS system control. The FLC parameters are then tuned using a genetic algorithm (GA). The tuning process is first formulated as a single-objective optimization problem based on the human sensitivity and conventional r.m.s. amplitude criteria separately. The simulation results reveal that the optimization of a fuzzy AS based on the common r.m.s. amplitude criterion not only does not result in the optimal ride index, but also causes a considerable increase in the energy consumption. Moreover, in order to accommodate the conflicting characteristics of the AS system, the FLC parameters are tuned on the basis of a multi-objective fitness function incorporating human sensitivity, suspension travel, and energy consumption. The simulation results prove the effectiveness of the optimized FLC in hitting the simultaneous targets of ride comfort improvement as well as suspension travel and energy consumption reduction.

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“…There are many published results on the use of shaker table tests to measure discomfort indices. For instance, in [7] 30 men and 30 women participants were exposed for 8-second vibratory inputs in an experimental study with unrestrained sitting positions on the vibrator plate; in [8] 16 subjects participated in the tests and 6 different automotive seat combinations were attached to a shaker to conduct experiments to define "bad", "worst" and "good" seats. Although this area of research has been explored extensively, the test setups may not capture the complexity of vibration input required and further they do not include the effects of the surroundings inside the vehicle.…”

Section: Introductionmentioning

confidence: 99%

“…At around 20-30 Hz head experiences resonance. Four Hz is observed to create discomfort in humans because shoulder, neck and head resonate in some combination at around this frequency [7,9,12].…”

Section: Introductionmentioning

confidence: 99%

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Quantification of Human Discomfort in a Vehicle Using a Four-Post Rig Excitation

Ibicek

Thite

2012

Journal of Low Frequency Noise, Vibration and Active Control

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The ride comfort of a vehicle is a vital aspect determining competitiveness of vehicles. The comfort is intricately related to feelings of discomfort due to vibration. The discomfort depends on various dynamic aspects of the suspension-seat and surrounding system. In industry, the discomfort due to vibration is assessed by road testing on various surfaces; these road tests may not be accurately repeatable. Discomfort, in general, can be assessed by measurements based on a shaker table and seat combination. These results when used for "in vehicle situations" may not accurately indicate the level of human discomfort in a vehicle. In view of this, to quantify seated human discomfort in a vehicle, measurements were performed using a four-post rig simulator; the setup allows controlled in-situ experiments to be conducted. A group of six subjects were exposed to sinusoidal vibration at five magnitudes in the vertical direction for heave, roll and pitch motion. The objective is to develop a discomfort metric which could be used to compare vehicles. The preliminary results show varying significance of roll, pitch and heave motion. The results, however, confirm the nonlinear variation of perception as a function of the physical stimulus. The test setup can be used to study the effects of complex road inputs and eventually may contribute towards reduced reliance on road tests.

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Equal comfort contours for whole body vertical, pulsed sinusoidal vibration

Cited by 37 publications

References 5 publications

Frequency-dependence of discomfort caused by vibration and mechanical shocks

Frequency-dependence of discomfort caused by vibration and mechanical shocks

Genetic optimization of a fuzzy active suspension system based on human sensitivity to the transmitted vibrations

Quantification of Human Discomfort in a Vehicle Using a Four-Post Rig Excitation

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