F2008-12-003
Methodologies and Tools for Objectivising Subjective Aspects of Long Distance Driving Vehicle Comfort
Methodologies and Tools for Objectivising Subjective Aspects of Long Distance Driving Vehicle Comfort
Authors: Dr. Jens Meschke, Urs Reichart, VOLKSWAGEN AG Group Research
"Driving longer and arriving more relaxed" - What are the costumer needs? This is the main question to be answered by results of investigations which were done by Volkswagen Group Research. Charac-terisation of vehicle comfort considering especially long distance rides by objective parameters was investigated. Former results indicated that seating comfort, interior acoustics, interior climate and driv-ing behaviour play a main role for subjective impression of test candidates. Drivers evaluation de-pends on his personal experience, the characteristics of the vehicle and environmental conditions (road characteristics, traffic, weather etc.). To investigate this more deeply and to achieve validated objec-tive parameters one single vehicle with different properties concerning driving behaviour (suspension, gear shift points of transmission), seating and interior acoustics was evaluated by a number of certain test persons. Test persons were all men with similar age, size, weight and experience in long distance driving. Tests were conducted on the same highway in the middle of a week and similar weather and traffic conditions. The suspension and steering wheel behaviour of the test vehicle could be modified in two conditions, one comfort oriented and the other sporty. Also in the comfort mode the interior acoustics were modified in that way that two dominating engine orders were reduced by use of an active noise cancellation system. In the sporty mode other engine orders were amplified to achieve a powerful "V8-sound". To differentiate between sporty and comfort drive two different seats were mounted on drivers side. Drivers evaluation was investigated by questionnaires during the driving tests by an automatic record system and at the end of each test. In parallel several data of the vehicle CAN-Bus were recorded (e.g. vehicle and engine speed, acceleration) and also interior noise and accelerations at relevant positions (e.g. seat rail, floor) were measured. Main objective of these tests was to find correlations between the subjective ratings of the test persons and vehicle characteristics/conditions. Concerning acoustics for instance sound pressure level (SPL) and Speech Intelligibility Index (SII) were investigated. This paper presents a model of the interaction between environment (traffic conditions), driver and vehicle. It can be stated that a vehicle is the "mediator" between environment and driver. The drivers evaluation of vehicle characteristics depend on environment (e.g. sunny weather, rough road) and traf-fic conditions. To perform the task of driving a long distance the driver quests for an optimum within his personal range of "challenge" and "work load". This means challenge must not be to high (stress) but also not too low (boredom). Results show that considering the overall evaluation of the vehicle characteristics its differences were noticed significantly, whereas differences in ratings of test persons were not significant. Traffic condi-tions seem to be significant, too.
This abstract is supplemented by a PDF, which can be viewed here.
Session: Comfort, Body