Simulation of the Performance Based Standards (PBS) Low-Speed 90° Turn Test in TruckSim by Jumping Back in Time

In 2008 the Australian National Transport Commission (NTC) published a reference document titled Performance Based Standards Scheme - The Standards And Vehicle Assessment Rules [1]. This document describes a series of testing requirements known as Performance Based Standards (PBS) to be used for certifying truck configurations acceptable for the Australia highway system. The PBS specification allows for both in-vehicle testing and numerical analysis using simulation tools such as TruckSim [2].

Several of the PBS tests require a Low-Speed 90° Turn, used to measure tracking behavior and tire friction utilization. This test presents an unusual simulation challenge because the driver is required to closely track a path with the outer sidewall of the outside front tire. A human driver must learn the response of the vehicle in order to steer it accurately through the test. This paper describes how the learning process was simulated in TruckSim by using the built-in scripting language to monitor the tracking of the point of interest (outer sidewall of a tire) for drifting from the target path. If the drifting exceeds a limit, the script commands the simulation to jump back in time and continue with modified control settings. The simulation option to jump back in time requires software considerations that have not been included in commercial vehicle dynamics software until recently. This paper describes how the new capability is applied to mimic an advanced driver for this standard PBS maneuver using TruckSim.