Trailer Steering: an Australian Research Perspective and Application for By-wire Control

Dangerous goods vehicles, in particular those carrying fluid loads, have been identified as needing to meet stringent performance requirements within the Performance Based Standards (PBS) developed by the National Roads and Transport Commission in Australia. The opportunity to control the lateral dynamics of these multiply-articulated vehicles with active steering systems deployed on the trailers has been identified by a number of groups worldwide, but research into the dynamics, and modern control strategies to modify these dynamics, is sparse. RABiT at the University of Melbourne identified a need to address the gaps in this knowledge and has proposed a prototype vehicle with trailer steer control that could gain unrestricted route access under PBS with significant mass increases when compared to current, similarly configured vehicles. This paper illustrates the modelling approach taken for the development of a trailer steer control algorithm, in which the hitch angle between successive articulated units is allowed to be large (in contrast to most previous work where small angle assumptions are made). It is shown by comparison with simulations performed with a complex, nonlinear 3D model that a single-track, yaw-plane model with linear tyre behaviour (but large hitch angles) is able to capture the dynamics effects important for trailer tracking control (including the onset of jackknife). A partial feedback-linearising controller is developed, which seeks to make the axle of each semitrailer unit track the path of the preceding hitch point. It is shown that considerable improvements in low-speed offtracking can be made, and that rearward amplification of lateral accelerations at high-speeds can be reduced. TRAILER STEERING: AN AUSTRALIAN RESEARCH PERSPECTIVE AND APPLICATION FOR BY-WIRE CONTROL Craig Fletcher, Chris Manzie, Malcolm Good. Research Centre for Advanced By-Wire Technologies (RABiT) Department of Mechanical and Manufacturing Engineering, University of Melbourne