This paper concentrates on the trailing arm air suspensions available on the rear tandem drive axles of some heavy prime movers. On such vehicles, the application of air suspension is believed to have a series of advantages including road friendly characteristics, better load sharing and self ride height adjustment. However, air suspensions are proved unstable under dynamic situations possessing inadequate support, harsh ride and chaotic response. In this paper, some individual components of the air suspension are modeled as well as the suspension vibration model and the pneumatic transmission line model. These models are then simulated using both SIMULINK and analytical techniques to find the causes for the adverse characteristics. From the simulation it is identified, the harsh ride is caused by insufficient flow in the transmission line whereas the chaotic response, at least to some extent, is found to be due to the haphazard design of the analogue feedback control system, especially the ride height control valve (HCV). (Author/publisher) For the covering entry of this conference, please see ITRD abstract no. E208431.
Samenvatting