Much research has been carried out in recent years to estimate perceived comfort levels for passengers in motor vehicles. This interest is in part due to the introduction of specific provisions (e.g. Law 81/08 in Italy). Another factor is the increased interest and attention of customers. These studies have concentrated in large part on driver position. However, this work describes an application of postural analysis of with results obtained via data acquired during the interaction between the passenger and the dashboard.
Tests were carried out in the Virtual Reality Laboratory (VR Lab) at the University of Salerno using a physical mock-up of a passenger car seat involving a fully reconfigurable seating buck. The interior of a FIAT Grande Punto, MY 2013, was configured by setting the seating-buck parameters. Twenty participants were asked to sit in the car seat with their shoulders against the seatback. They were then asked to reach each of the dashboard buttons. To acquire the angles of the subject’s joints, pictures were taken and processed using KINOVEA® software. Each subject was subsequently given a questionnaire to analyze subjective comfort perception for their neck, back, shoulders, arms, upper-arms and wrists. A virtual model of the front seat of a Fiat Grande Punto was developed in CATIA software environment, and each action involved in reaching a position and using a command was simulated using DELMIA® software. The anthropometric data for each subject was used to perform the virtual analyses. Reachability and visibility analyses - important factors in comfort perception - were carried out. CaMAN® software was used for the virtual assessment of upper-limb postural comfort. Statistical analyses were performed using SPSS® software to investigate potential correlations between:
anthropometric data and comfort perceptions resulting from the questionnaires;
anthropometric data and comfort indexes obtained by CaMAN® software;
comfort indexes obtained by CaMAN® and from the questionnaires.
The analyses showed a lack of strong correlations between anthropometric and comfort indexes calculated both by the questionnaires and by CaMAN®. Further analyses allowed us to understand the reasons for the weak correlation between the CaMAN and questionnaire results. Reachability was shown to strongly affect global comfort perception due to the perception of postural comfort. To understand the influence of reachability on global comfort perception, a new comfort perception function was developed, leading to some very interesting results.