In case of design of passenger vehicles, one of the priorities is how the dynamics behavior shall be perceived by the vehicle occupants. One of many such handling parameters is the vehicle body roll, which is usually quantified by the vehicle's Steady State Roll Gradient. This number gives an indication of the rotation of the vehicle body in response to unit lateral force acting on the vehicle, as in the case of cornering. However it does not necessarily indicate the roll as sensed by a person seated inside it.
A study showed that the subjective feel is not entirely dependent on roll gradient. In some cases the occupant may feel more confident and comfortable in a vehicle with a relatively higher roll gradient, or vice versa. In such cases, designing for roll gradient alone may not serve the purpose of secure and comfortable feel. To account for this discrepancy, a study was carried out to quantify the motion felt by the occupant.
It was found that the seating position is a vital element influencing the sensation generated by the rolling motion. Incorporating the same, the already established roll gradient was augmented and the term “Perceptible Roll” was defined. The results were compared to subjective ratings for the same vehicles and were found to have a much better correlation. The parameter gives an accurate index for the magnitude of motion felt by the occupant, thereby giving a better quantification for the discomfort generated as a result of body roll. The same has been detailed in the following work.
