Influence of steering vibration on vehicle speed recognition and comfortableness in cabin.
Time: 6:20 am
Author: Eiji Yoshioka
Abstract ID: 2006
In recent years, electric vehicles are becoming more popular. This transition makes interior noise and vibration smaller according to the engine rest and makes interior more comfortable. On the other hand, this reduction has a possibility to decrease important information for drivers. In this study, we focused on the steering vibration as the vehicle speed information and investigated the influence on the comfortableness in cabin for the compatibility through subjective evaluation test using a simple driving simulator. In the test, vehicle speed controlling task was given to the participants without speed meter at acceleration conditions. In addition, subjective evaluation about the comfortability to the presented sound and vibration was conducted after the speed recognition test. As the presented steering vibration, the following four patterns were prepared. 1: internal combustion engine noise and vibration with road and wind noise (background noise), 2: electric-powered vehicle noise without vibration (background noise without vibration), 3: tire vibration with background noise, 4: motor vibration with background noise. As the result, the steering vibration of internal combustion engine or motor was found to be suitable stimuli for compatibility between the speed recognition performance and the comfortability in cabin.
Frequency dependence of vertical whole-body vibration perception – is your car rattling or humming?
Time: 6:00 am
Author: Anna Schwendicke
Abstract ID: 2885
Humans perceive whole-body vibration in many daily life situations. Often they are exposed to whole-body vibration in combination with acoustic events. Sound and vibration usually stems from the same source, for example concerts or travelling in vehicles, such as automobile, aircrafts, or ships. While we can describe acoustic stimuli using psychoacoustic descriptors such as loudness or timbre, the description human perception of whole body vibration frequently has been reduced to comfort or quality in the past. Unlike loudness or timbre, comfort and quality are dependent on the overall context. Especially in vehicles expectations might differ lot between different vehicle classes. Previous studies have evaluated a large range of suitable descriptors for whole-body vibrations that are independent of context. They suggest that certain descriptors are driven to a large extend by the frequency content of the vibration. This study systematically investigates the influence of frequency content on the perception of whole-body vibration varying frequency content and intensity of the vibrations. The results verify the frequency dependence of specific descriptors and identify the respective frequency ranges.
Perception thresholds for whole-body vibrations on an airplane seat
Time: 6:40 am
Author: Louis Krause
Abstract ID: 2107
The comfort during a flight on an aircraft is important for passengers. Like many other physical factors, vibrations of the airplane may negatively affect comfort. To understand the impact of vibration on comfort, it is important to know in which way the vibrations transmitted through the seat affects the perception of whole-body-vibrations. In this study, perception thresholds for vertical sinusoidal whole-body vibrations with frequencies between 20 Hz and 75 Hz were determined on a vibration platform with a typical economy class aircraft seat bench. Acceleration levels were recorded with accelerometers placed at the right rear seat rail and inside a seat cushion between the seat surface and the participant. The results show a distinct frequency dependency of the detection thresholds when measured at the seat rail. When taking the difference between the two measurement positions into account and describing the thresholds by the acceleration levels at the seat cushion, the determined perception thresholds are nearly frequency independent up to 50 Hz. This finding is in good agreement with literature data suggesting that the specific experimental setup does not play a big role in this frequency range. Differences above 50 Hz might be explained by the additional armrests in the present study.