Abstract
Keywords - Transient understeer, Transient oversteer, Subjective assessment, Objective test, Handling test
Abstract - Regarding on the evaluation of handling performance, subjective assessment is currently the only criteria to make the final judgement on the design of a vehicle system. The current vehicle dynamics concept employed to analyze objective tests or computer simulations with respect to the subjective assessment is based on a bicycle model. In using the existing vehicle dynamics for that purpose, it has been known to have two major problems: (1) The existing vehicle dynamics cannot realistically explain the subjective assessment at all. (2) The linear concept of the existing vehicle dynamics cannot practically represent the nonlinear behaviour of a complex vehicle system in reality.
Since a new concept of vehicle dynamics regarding on transient steer characteristic presented here is based on subjective assessment, the concept can naturally explain the subjective assessment in terms of engineering language. This concept is also not limited to any linear assumption at all. Transient understeer and oversteer are successfully formulated here. These formulations are successfully validated through four handling tests with numerous test sets. The correlation results show that there exists a very good correlation between subjective assessment and objective measurement.