The relationship between the lateral acceleration experienced by the rear trailer of a multiarticulated vehicle and that input by the drivers steering action is known as lateral acceleration gain (LAG). LAG can be considered as a transfer function between lateral acceleration at the steer axle and rear trailer, which varies with frequency, magnitude and duration of the input. Work conducted for the Western Australian Department of Planning and Infrastructure (DPI) identified that LAG was an important aspect of vehicle dynamics, not fully covered by existing Australian performance-based regulations. This work recommended further research into LAG to improve the understanding of the safety implications of this phenomenon. This paper aims to partially address this recommendation by studying how a range of factors affect LAG. Computer modelling and field test results of an investigation into LAG for two different vehicles are presented. The results show that the LAG characteristics of different vehicles vary markedly, and that the peak response of a vehicle can vary accordingly. This paper also shows that LAG depends on the duration and magnitude of an input, as well as the frequency, and that mechanical suspensions can reduce LAG relative to air suspensions at low input levels. (a) For the covering entry of this conference, please see ITRD abstract no. 0612AR242E.
Abstract