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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 modeling methods used in the commercial BikeSim® simulation package to represent alternative suspension design concepts. The modeling method used for automotive suspensions is applied to define generic suspensions for motorcycles. This method can represent multi-link suspension systems as well as traditional motorcycle suspensions with telescopic front forks and rear swing arms. Comparisons of two suspension types show a multi-link suspension can provide advantages over the traditional system for braking, acceleration (throttle), and cornering. Similar comparisons made with a chain-drive powertrain and a shaft-drive powertrain show less jacking with the chain-drive design. Although the math models include complex nonlinear motions, the computational efficiency supports fast operation; on a 2.8 GHz PC the simulation runs eight times faster than real time.

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.