The increasing use and implementation of computer simulation in the vehicle engineering process has allowed for complex vehicles to be designed and tested in a virtual environment prior to a full-size vehicle being built. This approach is of particular importance in the commercial truck markets of Australia, New Zealand, and South Africa where large truck-trailer combinations, often referred to as “road trains”, are becoming more common. Such trucks can carry more freight per vehicle; however their overall length and mass means additional safety standards must be in place to ensure a safely operating vehicle. To that end the National Transport Commission (NTC) Australia has been developing vehicle specifications called Performance Based Standards, or PBS. Performance Based Standards include specifications for longitudinal performance such as Startability, Gradeability, Acceleration Capability, and Tracking ability on a straight path. Directional performance tests are Low Speed Swept Path, Frontal Swing and Tail Swing, Steer Tire Friction Demand, Static Rollover Threshold, Rearward Amplification, High-Speed Offtracking, and Yaw Damping Coefficient.
The PBS specification allows both in-vehicle testing and numerical analysis. This paper describes how the PBS procedures are handled in the commercially available TruckSim vehicle simulation tool. It also describes how a set of large vehicle models made with a five-axle towing unit and various numbers of trailers with four axles are used to represent a majority of the “road train” vehicles.