This paper essentially describes and compares, in generic terms, the characteristics of slow response rear axle connected heavy vehicle bogie suspensions (both single and dual valve) to those of fast response connected axle mean ride height single valve controlled systems. The comparison between existing standard air spring system to state of the art analogue systems considers roll stability, dynamic load sharing, dynamic wheel loads, tyre wear patterns and life, vehicle handling stability, braking characteristics, vehicle bump steer, inherent damping characteristics, sensitivity to erroneous chassis flex feedback, response to terrain or road surface variations, valve state of repair sensitivity, damper state of repair sensitivity, stability during burst bag situations, drive line torsional vibration characteristics, compressed air consumption, drive line component life and most importantly risk of driver fatigue. The comparison is highlighted by examination of the seat pad vibration characteristics of a truck fitted with original and modified air suspension systems operating off road at 15 and 40 km/h, respectively. On road vibration characteristics are also presented. Discussion is supported by brief consideration of air spring suspension analytical models so far developed. It is revealed that fast response mean ride height analogue controlled systems attract considerable advantages, so much so that such systems herald a new benchmark for heavy vehicle genuine road, vehicle and driver friendly suspensions. (Author/publisher) For the covering entry of this conference, please see ITRD abstract no. E205861.
Samenvatting