Introduction
The ride comfort concept sweeps over many disciplines in automotive engineering. The vehicle parameters such as suspension spring stiffness and damping coefficient, the temperature control inside the cabin, the ergonomics of the car and many other factors contribute to this quality. When vehicles travel on the irregular roads, they are always subjected to excitation from braking, acceleration and inertial forces on a curved track, which causes discomfort to the driver. The excitation sources for these vibrations can be road roughness, wheel assembly, driveline excitation, engine excitation, aerodynamic forces and transmission excitation. Usually, road roughness will be the major source that excites the car body through wheel assembly …show more content…
The first one is implemented for the purpose of obtaining the necessary data for calculating the ride index and the second one is for the purpose of collecting the fundamental parameter values used in the modeling phase of the full-car simulation. Firstly, four convenient vehicles were chosen, namely two of them are medium sedan passenger cars and the other two of them are light commercial vehicles. After choosing the vehicles, another important task is choosing convenient roads. Six roads having different properties (asymmetric traverse, dirt road, paved, highway, test track, and patched road) were chosen for the same purposes as choosing the vehicles. Observing the effect of engine vibrations on the ride comfort and exploring its importance are main purposes of the …show more content…
A linear relationship exists between subjective and objective results. The correlation of unweighted, ISO 2631 and BS 6841 weighted values are analyzed to determine which of the methods give good correlation. All three of the methods (unweighted, ISO 2631 and BS 6841) are found to give good correlation as far as the RMS, RMQ, VDV and eVDV values are concerned for vertical acceleration as well as multi-axis translation values. The multi-axis values are however dominated significantly by the vertical acceleration values. All the correlations, except AAP, exhibit a linear trend. The trend for AAP is well defined but non-linear and a big increase in objective value only results in a small increase in subjective value as the terrain roughness increases. The trends for ISO 2631 and BS 6841 are in very good agreement. The difference can be attributed to the relatively small difference in the weighting curves. It can be concluded that the vertical acceleration gives the best, and in fact the only reliable correlation between subjective and objective ride comfort values. The same conclusion can be made from the AAP and VDI 2057 correlation where only vertical values were used. The pitch and roll acceleration of the vehicle body is experienced as vertical acceleration by the respondents and therefore the pitch
The ride comfort concept sweeps over many disciplines in automotive engineering. The vehicle parameters such as suspension spring stiffness and damping coefficient, the temperature control inside the cabin, the ergonomics of the car and many other factors contribute to this quality. When vehicles travel on the irregular roads, they are always subjected to excitation from braking, acceleration and inertial forces on a curved track, which causes discomfort to the driver. The excitation sources for these vibrations can be road roughness, wheel assembly, driveline excitation, engine excitation, aerodynamic forces and transmission excitation. Usually, road roughness will be the major source that excites the car body through wheel assembly …show more content…
The first one is implemented for the purpose of obtaining the necessary data for calculating the ride index and the second one is for the purpose of collecting the fundamental parameter values used in the modeling phase of the full-car simulation. Firstly, four convenient vehicles were chosen, namely two of them are medium sedan passenger cars and the other two of them are light commercial vehicles. After choosing the vehicles, another important task is choosing convenient roads. Six roads having different properties (asymmetric traverse, dirt road, paved, highway, test track, and patched road) were chosen for the same purposes as choosing the vehicles. Observing the effect of engine vibrations on the ride comfort and exploring its importance are main purposes of the …show more content…
A linear relationship exists between subjective and objective results. The correlation of unweighted, ISO 2631 and BS 6841 weighted values are analyzed to determine which of the methods give good correlation. All three of the methods (unweighted, ISO 2631 and BS 6841) are found to give good correlation as far as the RMS, RMQ, VDV and eVDV values are concerned for vertical acceleration as well as multi-axis translation values. The multi-axis values are however dominated significantly by the vertical acceleration values. All the correlations, except AAP, exhibit a linear trend. The trend for AAP is well defined but non-linear and a big increase in objective value only results in a small increase in subjective value as the terrain roughness increases. The trends for ISO 2631 and BS 6841 are in very good agreement. The difference can be attributed to the relatively small difference in the weighting curves. It can be concluded that the vertical acceleration gives the best, and in fact the only reliable correlation between subjective and objective ride comfort values. The same conclusion can be made from the AAP and VDI 2057 correlation where only vertical values were used. The pitch and roll acceleration of the vehicle body is experienced as vertical acceleration by the respondents and therefore the pitch