Subjective and objective vehicle handling behaviour

Abstract

This thesis presents results from a research project seeking to correlate subjective and objective measures of automobile handling. An underlying goal of the work was to demonstrate how a relatively simple lumped parameter model, suitable for effective use at the early stages of vehicle design, could be used to predict both the objective responses and subjective feel of the car. The work associated with the project was centred around sixteen configurations of a prototype saloon car. Objective evaluation included ISO defined steady state, step input, and frequency response testing. Subjective assessments were conducted by eight trained test drivers who supplied feedback in the form of numerical ratings on a questionnaire covering various aspects of handling. Examination of the two sets of data highlighted aspects of handling for which driver ratings correlated with objective data. It was also possible to quantify the average effect each objective response parameter had on driver ratings and thus to identify responses which most strongly influence subjective ratings. In addition a lumped parameter model allowing for lateral, yaw and roll degrees of freedom was validated against the experimental data. This validation demonstrated that the model was capable of accurate steady state and transient predictions both in the linear and non-linear range. The work concludes with a brief discussion about how the validated model, combined with the knowledge gained from the correlation work, could be used by engineers to streamline the design and development process